Weaning from mechanical ventilation in the operating room: a systematic review

BACKGROUND

Postoperative pulmonary complications (PPCs) are associated with postoperative mortality and prolonged hospital stay. Although intraoperative mechanical ventilation (MV) is a risk factor for PPCs, strategies addressing weaning from MV are understudied. In this systematic review, we evaluated weaning strategies and their effects on postoperative pulmonary outcomes.

METHODS

Our protocol was registered on PROSPERO (CRD42022379145). Eligible studies included randomised controlled trials and observational studies of adults weaned from MV in the operating room. Primary outcomes included atelectasis and oxygenation; secondary outcomes included lung volume changes and PPCs. Risk of bias was assessed using the Cochrane Risk of Bias (RoB2) tool, and quality of evidence with the GRADE framework.

RESULTS

Screening identified 14 randomised controlled trials including 1719 patients; seven studies were limited to the weaning phase and seven included interventions not restricted to the weaning phase. Strategies combining pressure support ventilation (PSV) with positive end-expiratory pressure (PEEP) and low fraction of inspired oxygen (FiO2) improved atelectasis, oxygenation, and lung volumes. Low FiO2 improved atelectasis and oxygenation but might not improve lung volumes. A fixed-PEEP strategy led to no improvement in oxygenation or atelectasis; however, individualised PEEP with low FiO2 improved oxygenation and might be associated with reduced PPCs. Half of included studies are of moderate or high risk of bias; the overall quality of evidence is low.

CONCLUSIONS

There is limited research evaluating weaning from intraoperative MV. Based on low-quality evidence, PSV, individualised PEEP, and low FiO2 may be associated with reduced postoperative pulmonary outcomes.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO (CRD42022379145).

Impact of spinal or epidural anaesthesia on perioperative outcomes in adult noncardiac surgery: a narrative review of recent evidence

Spinal and epidural anaesthesia and analgesia are important anaesthetic techniques, familiar to all anaesthetists and applied to patients undergoing a range of surgical procedures. Although the immediate effects of a well-conducted neuraxial technique on nociceptive and sympathetic pathways are readily observable in clinical practice, the impact of such techniques on patient-centred perioperative outcomes remains an area of uncertainty and active research. The aim of this review is to present a narrative synthesis of contemporary clinical science on this topic from the most recent 5-year period and summarise the foundational scholarship upon which this research was based. We searched electronic databases for primary research, secondary research, opinion pieces, and guidelines reporting the relationship between neuraxial procedures and standardised perioperative outcomes over the period 2018-2023. Returned citation lists were examined seeking additional studies to contextualise our narrative synthesis of results. Articles were retrieved encompassing the following outcome domains: patient comfort, renal, sepsis and infection, postoperative cancer, cardiovascular, and pulmonary and mortality outcomes. Convincing evidence of the beneficial effect of epidural analgesia on patient comfort after major open thoracoabdominal surgery outcomes was identified. Recent evidence of benefit in the prevention of pulmonary complications and mortality was identified. Despite mechanistic plausibility and supportive observational evidence, there is less certain experimental evidence to support a role for neuraxial techniques impacting on other outcome domains. Evidence of positive impact of neuraxial techniques is best established for the domains of patient comfort, pulmonary complications, and mortality, particularly in the setting of major open thoracoabdominal surgery. Recent evidence does not strongly support a significant impact of neuraxial techniques on cancer, renal, infection, or cardiovascular outcomes after noncardiac surgery in most patient groups.

ARISCAT and LAS VEGAS risk scores for predicting postoperative pulmonary complications after cardiac surgery: a cohort study

Background

Postoperative pulmonary complications (PPCs) could lead to morbidity, mortality, and prolonged hospital stay. Different risk-scoring systems are used to predict the identification of patients at risk of developing PPCs. The diagnostic accuracies of the Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) and Local Assessment of Ventilatory Management During General Anaesthesia for Surgery (LAS VEGAS) risk scores are compared in prediction of PPCs taking pulmonary complication as the gold standard in cardiac surgery.

Materials and methods

A prospective cohort study with consecutive sampling technique. A total of 181 patients were included. Quantitative data is presented as simple descriptive statistics giving mean and standard deviation, and qualitative variables are presented as frequency and percentages. Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracies are also calculated.

Results

Total 181 post-cardiac surgery patients were analyzed. The median [interquartile range] of age, height, weight, and BMI were 60.0 [52.0-67.0] years, 163.0 [156.0-168.0] cm, 71.0 [65.0-80.0] kg and 27.3 [24.2-30.4] kg/m2. 127 (70.2%) were male, and 54 (29.8%) were female. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of ARISCAT for the prediction of PPCs were (94.9%, 4.65%, 76.1%, 22.9% and 73.4%), whereas LAS VEGAS were (97.1%, 4.65%, 76.5%, 33.3% and 75.1%), respectively.

Conclusion

Both the ARISCAT and LAS VEGAS risk scores are of limited value in cardiac surgery patients for the prediction of postoperative pulmonary complications, based on the predicted scores in this study.

Combining Spirometry and the ARISCAT Respiratory Risk Assessment Can Improve Postoperative Outcomes and Reduce Mortality Risk in Mexico

Introduction

Although a major goal of preoperative evaluation is to identify risk factors and improve postoperative outcomes, current clinical guidelines in Mexico indicate that preoperative spirometry should only be performed on patients with pulmonary disease. The aim of this study was to compare the incidence of postoperative complications (POC), mortality, and risk factors among adults who did or did not undergo preoperative spirometry, based on their Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) risk level.

Material and methods

An observational, retrospective and comparative study design was used to identify 2059 patients from the General Hospital of Mexico who had an ARISCAT assessment during 2013-2017. Patients were classified in two groups: ARISCAT with spirometry (n = 1306) and ARISCAT without spirometry (n = 753). Chi-square, Fisher's exact test and the Student's t-tests were used to compare groups. Logistic regression was used to identify factors associated with an increased risk of POC and mortality.

Results

In the ARISCAT with spirometry group, 11% of patients had POC, compared with 48% of patients in the ARISCAT without spirometry group. High-risk ARISCAT patients who did not receive spirometry had higher mortality (18%), than those who underwent spirometry (0.4%). Logistic regression results indicate that not performing preoperative spirometry increases the probability of POC and mortality.

Conclusions

Our findings suggest that the combined use of preoperative spirometry and ARISCAT is associated with reduced POC and mortality. Future clinical guidelines should recommend the use of preoperative spirometry for patients with a moderate or high ARISCAT level in Mexico.

Exploring phenotype-based ventilator parameter optimization to mitigate postoperative pulmonary complications: a retrospective observational cohort study

PURPOSE

To identify tidal volume (VT) and positive end-expiratory pressure (PEEP) associated with the lowest incidence and severity of postoperative pulmonary complications (PPCs) for each phenotype based on preoperative characteristics.

METHODS

The subjects of this retrospective observational cohort study were 34,910 adults who underwent surgery, using general anesthesia with mechanical ventilation. Initially, the least absolute shrinkage and selection operator regression was employed to select relevant preoperative characteristics. Then, the classification and regression tree (CART) was built to identify phenotypes. Finally, we computed the area under the receiver operating characteristic curves from logistic regressions to identify VT and PEEP associated with the lowest incidence and severity of PPCs for each phenotype.

RESULTS

CARTs classified seven phenotypes for each outcome. A probability of the development of PPCs ranged from the lowest (3.51%) to the highest (68.57%), whereas the probability of the development of the highest level of PPC severity ranged from 3.3% to 91.0%. Across all phenotypes, the VT and PEEP associated with the most desirable outcomes were within a small range of VT 7-8 ml/kg predicted body weight with PEEP of between 6 and 8 cmH2O.

CONCLUSIONS

The ranges of optimal VT and PEEP were small, regardless of the phenotypes, which had a wide range of risk profiles.

Association between reversal agents (sugammadex vs. neostigmine) for neuromuscular block and postoperative pulmonary complications: A retrospective analysis

AIMS

Residual neuromuscular blockade has been linked to pulmonary complications in the postoperative period. This study aimed to determine whether sugammadex was associated with a lower risk of postoperative pulmonary complications (PPCs) compared with neostigmine.

METHODS

This retrospective cohort study was conducted in a tertiary academic medical center. Patients ≥18 year of age undergoing noncardiac surgical procedures with general anesthesia and mechanical ventilation were enrolled between January 2019 and September 2021. We identified all patients receiving rocuronium and reversal with neostigmine or sugammadex via electronic medical record review. The primary endpoint was a composite of PPCs (including pneumonia, atelectasis, respiratory failure, pulmonary embolism, pleural effusion, or pneumothorax). The incidence of PPCs was compared using propensity score analysis.

RESULTS

A total of 1786 patients were included in this study. Among these patients, 976 (54.6%) received neostigmine, and 810 (45.4%) received sugammadex. In the whole sample, PPCs occurred in 81 (4.54%) subjects (7.04% sugammadex vs. 2.46% neostigmine). Baseline covariates were well balanced between groups after overlap weighting. Patients in the sugammadex group had similar risk (overlap weighting OR: 0.75; 95% CI: 0.40 to 1.41) compared to neostigmine. The sensitivity analysis showed consistent results. In subgroup analysis, the interaction P-value for the reversal agents stratified by surgery duration was 0.011.

CONCLUSION

There was no significant difference in the rate of PPCs when the neuromuscular blockade was reversed with sugammadex compared to neostigmine. Patients undergoing prolonged surgery may benefit from sugammadex, which needs to be further investigated.

Oxygenation Index and Oxygen Saturation Index for Predicting Postoperative Outcome in Patients Undergoing Emergency Surgery: A Prospective Cohort Study

Background

The OI was originally evaluated as a prognostic tool for acute hypoxemic respiratory failure in children and was an independent predictor for mortality in adult patients with acute respiratory distress syndrome (ARDS).

Methods

Oxygenation index and OSI of 201 adult patients undergoing emergency surgery were evaluated at different time points. The primary objective of this study was to find the correlation between OI and OSI. The secondary objectives were to find the prognostic utility of OI and OSI for postoperative mechanical ventilation and mortality.

Results

Significant statistical correlation was found between OI and OSI both at the beginning (r 2 = 0.61; p < 0.001) and immediately after surgery (r 2 = 0.47; p < 0.001). Oxygen saturation index at the beginning [area under the receiver operating characteristics curve (AUROC) (95% CI) 0.76 (0.62-0.89); best cutoff 3.9, sensitivity 64% and specificity 45%] and immediately after surgery [AUROC (95% CI) 0.82 (0.72-0.92); best cutoff 3.57, sensitivity 79%, and specificity 62%] were reasonable predictors of the requirement of invasive ventilatory support. Exploratory analysis reported that older age (p = 0.02), higher total leukocyte count (p = 0.002), higher arterial lactate (p = 0.02), and higher driving pressure (p < 0.001) were independently associated with hospital mortality.

Conclusion

In adult patients undergoing emergency laparotomy under general anesthesia, OI and OSI were found to be correlated. Both metrics demonstrated reasonable accuracy in predicting the need for invasive ventilatory support beyond 24 hours and hospital mortality.

How to cite this article

Thakuria R, Ernest EE, Chowdhury AR, Pangasa N, Kayina CA, Bhattacharjee S, et al. Oxygenation Index and Oxygen Saturation Index for Predicting Postoperative Outcome in Patients Undergoing Emergency Surgery: A Prospective Cohort Study. Indian J Crit Care Med 2024;28(7):645-649.

Incidence and risk factors of pulmonary complications after lung cancer surgery: A systematic review and meta-analysis

Postoperative pulmonary complications (PPCs) are associated with high mortality rates after lung cancer surgery. Although some studies have discussed the different risk factors for PPCs, the relationship between these factors and their impact on PPCs remains unclear. Hence, this study aimed to systematically summarize the incidence and determine the risk factors for PPCs. We conducted a systematic search of five English and four Chinese databases from their inception to April 1, 2023. A total of 34 articles (8 cohort studies and 26 case-control studies) (n = 31696, 5833 with PPCs) were included in the analysis. The primary outcome was the incidence of PPC. The secondary outcome was the odds ratio (OR) of PPCs based on the identified risk factors calculated by RevMan 5.4. A narrative descriptive summary of the study results was presented when pooling the results or conducting a meta-analysis was not possible. The pooled incidence of PPCs was 18.4 %. This meta-analysis demonstrated that TNM staging (OR 4.29, 95 % CI 2.59-7.13), chronic obstructive pulmonary disease (COPD) (OR 2.47, 95 % CI 1.80-3.40), smoking history (OR 2.37, 95 % CI 1.33-4.21), poor compliance with respiratory rehabilitation (OR 1.64, 95 % CI 1.17-2.30), male sex (OR 1.62, 95 % CI 1.28-2.04), diabetes (OR 1.56, 95 % CI 1.07-2.27), intraoperative bleeding volume (OR 1.44, 95 % CI 1.02-2.04), Eastern Cooperative Oncology Group score (ECOG) > 1 (OR 1.37, 95 % CI 1.04-1.80), history of chemotherapy and/or radiotherapy (OR 1.32, 95 % CI 1.03-1.70), older age (OR 1.18, 95 % CI 1.11-1.24), and duration of surgery (OR 1.07, 95 % CI 1.04-1.10) were significantly associated with a higher risk of PPCs. In contrast, the peak expiratory flow rate (PEF) (OR 0.99, 95 % CI 0.98-0.99) was a protective factor. Clinicians should implement targeted and effective interventions to prevent the occurrence of PPCs.

Association between driving pressure-guided ventilation and postoperative pulmonary complications in surgical patients: a meta-analysis with trial sequential analysis

BACKGROUND

Prior studies have reported inconsistent results regarding the association between driving pressure-guided ventilation and postoperative pulmonary complications (PPCs). We aimed to investigate whether driving pressure-guided ventilation is associated with a lower risk of PPCs.

METHODS

We systematically searched electronic databases for RCTs comparing driving pressure-guided ventilation with conventional protective ventilation in adult surgical patients. The primary outcome was a composite of PPCs. Secondary outcomes were pneumonia, atelectasis, and acute respiratory distress syndrome (ARDS). Meta-analysis and subgroup analysis were conducted to calculate risk ratios (RRs) with 95% confidence intervals (CI). Trial sequential analysis (TSA) was used to assess the conclusiveness of evidence.

RESULTS

Thirteen RCTs with 3401 subjects were included. Driving pressure-guided ventilation was associated with a lower risk of PPCs (RR 0.70, 95% CI 0.56-0.87, P=0.001), as indicated by TSA. Subgroup analysis (P for interaction=0.04) found that the association was observed in non-cardiothoracic surgery (nine RCTs, 1038 subjects, RR 0.61, 95% CI 0.48-0.77, P< 0.0001), with TSA suggesting sufficient evidence and conclusive result; however, it did not reach significance in cardiothoracic surgery (four RCTs, 2363 subjects, RR 0.86, 95% CI 0.67-1.10, P=0.23), with TSA indicating insufficient evidence and inconclusive result. Similarly, a lower risk of pneumonia was found in non-cardiothoracic surgery but not in cardiothoracic surgery (P for interaction=0.046). No significant differences were found in atelectasis and ARDS between the two ventilation strategies.

CONCLUSIONS

Driving pressure-guided ventilation was associated with a lower risk of postoperative pulmonary complications in non-cardiothoracic surgery but not in cardiothoracic surgery.

SYSTEMATIC REVIEW PROTOCOL

INPLASY 202410068.

Regional anesthesia in a patient with primary ciliary dyskinesia: A case report

BACKGROUND

Primary ciliary dyskinesia (PCD) is an inherited autosomal-recessive disorder of impaired mucociliary clearance characterized by chronic respiratory diseases, otolaryngological diseases, central nervous system abnormalities, reproductive system abnormalities, and cardiac function abnormalities. General anesthesia in these patients is associated with a higher incidence of respiratory complications than in patients without the disease.

CASE SUMMARY

A 16-year-old male patient was referred to the emergency room complaining of right ankle pain due to distal tibiofibular fracture. Three years prior, he had been diagnosed with PCD. At that time, he had experienced several episodes of pneumonia, sinusitis, and chronic middle ear infections, for which he underwent surgical interventions. At the current admission, he presented with cough and sputum but no other respiratory symptoms. A chest computed tomography scan revealed centrilobular ground-glass opacities in both lower lobes and a calcified nodule in the left lower lobe. For the surgical procedure and postoperative pain management, combined spinal-epidural anesthesia was employed. The patient's postoperative pain score was measured by the numerical rating scale (NRS). On the day of surgery, his NRS was 5 points. By the second postoperative day, the NRS score had decreased to 2-3 points. The epidural catheter was removed on the fourth day following the operation. The patient was subsequently discharged no respiratory complications.

CONCLUSION

We performed combined spinal-epidural anesthesia in a patient with PCD. The patient experienced no additional respiratory complications and was discharged with a low NRS score for pain.

Risk of Adverse Events Following Total Knee Arthroplasty in Asthma Patients

INTRODUCTION

Total knee arthroplasty (TKA) is a common procedure for which patient factors are known to affect perioperative outcomes. Asthma has not been specifically considered in this regard, although it is the most common inflammatory airway disease and predisposes to osteoarthritis.

METHODS

Adult patients undergoing TKA were identified from 2015 to 2021-Q3 M157 PearlDiver data sets. Asthma patients were matched to those without 1:1 based on age, sex, and Elixhauser Comorbidity Index (ECI). The incidence of 90-day adverse events and 5-year revisions were compared using multivariable logistic regression ( P < 0.0023). The matched asthma group was then stratified based on disease severity for analysis of 90-day aggregated (any, severe, and minor) adverse events.

RESULTS

Among 721,686 TKA patients, asthma was noted for 76,125 (10.5%). Multivariable analysis revealed that patients with asthma were at increased odds of multiple 90-day pulmonary, non-pulmonary, and aggregated adverse events, as well as emergency department visits. Furthermore, patients with asthma had 1.17 times greater odds of 5-year revisions ( P < 0.0001). Upon secondary analysis stratifying asthma by severity, patients with all severity levels of asthma showed elevated odds of adverse events after TKA. These associations increased in odds with increasing severity of asthma.

DISCUSSION

Over one-tenth of patients undergoing TKA were identified as having asthma, and these patients were at greater odds of numerous pulmonary and non-pulmonary adverse events (a trend that increased with asthma severity), as well as 5-year revisions. Clearly, patients with asthma need specific risk mitigation strategies when considering TKA.

LEVEL OF EVIDENCE

III.

Incidence and risk factors of postoperative pulmonary complications following total hip arthroplasty revision: a retrospective Nationwide Inpatient Sample database study

BACKGROUND

Postoperative pulmonary complications (PPCs) are among the most severe complications following total hip arthroplasty revision (THAR), imposing significant burdens on individuals and society. This study examined the prevalence and risk factors of PPCs following THAR using the NIS database, identifying specific pulmonary complications (SPCs) and their associated risks, including pneumonia, acute respiratory failure (ARF), and pulmonary embolism (PE).

METHODS

The National Inpatient Sample (NIS) database was used for this cross-sectional study. The analysis included patients undergoing THAR based on NIS from 2010 to 2019. Available data include demographic data, diagnostic and procedure codes, total charges, length of stay (LOS), hospital information, insurance information, and discharges.

RESULTS

From the NIS database, a total of 112,735 THAR patients in total were extracted. After THAR surgery, there was a 2.62% overall incidence of PPCs. Patients with PPCs after THAR demonstrated increased LOS, total charges, usage of Medicare, and in-hospital mortality. The following variables have been determined as potential risk factors for PPCs: advanced age, pulmonary circulation disorders, fluid and electrolyte disorders, weight loss, congestive heart failure, metastatic cancer, other neurological disorders (encephalopathy, cerebral edema, multiple sclerosis etc.), coagulopathy, paralysis, chronic pulmonary disease, renal failure, acute heart failure, deep vein thrombosis, acute myocardial infarction, peripheral vascular disease, stroke, continuous trauma ventilation, cardiac arrest, blood transfusion, dislocation of joint, and hemorrhage.

CONCLUSIONS

Our study revealed a 2.62% incidence of PPCs, with pneumonia, ARF, and PE accounting for 1.24%, 1.31%, and 0.41%, respectively. A multitude of risk factors for PPCs were identified, underscoring the importance of preoperative optimization to mitigate PPCs and enhance postoperative outcomes.

Electrical Impedance Tomography-based Ventilation Patterns in Patients after Major Surgery

Rationale: General anesthesia and mechanical ventilation have negative impacts on the respiratory system, causing heterogeneous distribution of lung aeration, but little is known about the ventilation patterns of postoperative patients and their association with clinical outcomes. Objectives: To clarify the phenotypes of ventilation patterns along a gravitational direction after surgery by using electrical impedance tomography (EIT) and to evaluate their association with postoperative pulmonary complications (PPCs) and other relevant clinical outcomes. Methods: Adult postoperative patients at high risk for PPCs, receiving mechanical ventilation on ICU admission (N = 128), were prospectively enrolled between November 18, 2021 and July 18, 2022. PPCs were prospectively scored until hospital discharge, and their association with phenotypes of ventilation patterns was studied. The secondary outcomes were the times to wean from mechanical ventilation and oxygen use and the length of ICU stay. Measurements and Main Results: Three phenotypes of ventilation patterns were revealed by EIT: phenotype 1 (32% [n = 41], a predominance of ventral ventilation), phenotype 2 (41% [n = 52], homogeneous ventilation), and phenotype 3 (27% [n = 35], a predominance of dorsal ventilation). The median PPC score was higher in phenotype 1 and phenotype 3 than in phenotype 2. The median time to wean from mechanical ventilation was longer in phenotype 1 versus phenotype 2. The median duration of ICU stay was longer in phenotype 1 versus phenotype 2. The median time to wean from oxygen use was longer in phenotype 1 and phenotype 3 than in phenotype 2. Conclusions: Inhomogeneous ventilation patterns revealed by EIT on ICU admission were associated with PPCs, delayed weaning from mechanical ventilation and oxygen use, and a longer ICU stay.

Utilising intraoperative respiratory dynamic features for developing and validating an explainable machine learning model for postoperative pulmonary complications

BACKGROUND

Timely detection of modifiable risk factors for postoperative pulmonary complications (PPCs) could inform ventilation strategies that attenuate lung injury. We sought to develop, validate, and internally test machine learning models that use intraoperative respiratory features to predict PPCs.

METHODS

We analysed perioperative data from a cohort comprising patients aged 65 yr and older at an academic medical centre from 2019 to 2023. Two linear and four nonlinear learning models were developed and compared with the current gold-standard risk assessment tool ARISCAT (Assess Respiratory Risk in Surgical Patients in Catalonia Tool). The Shapley additive explanation of artificial intelligence was utilised to interpret feature importance and interactions.

RESULTS

Perioperative data were obtained from 10 284 patients who underwent 10 484 operations (mean age [range] 71 [65-98] yr; 42% female). An optimised XGBoost model that used preoperative variables and intraoperative respiratory variables had area under the receiver operating characteristic curves (AUROCs) of 0.878 (0.866-0.891) and 0.881 (0.879-0.883) in the validation and prospective cohorts, respectively. These models outperformed ARISCAT (AUROC: 0.496-0.533). The intraoperative dynamic features of respiratory dynamic system compliance, mechanical power, and driving pressure were identified as key modifiable contributors to PPCs. A simplified model based on XGBoost including 20 variables generated an AUROC of 0.864 (0.852-0.875) in an internal testing cohort. This has been developed into a web-based tool for further external validation (https://aorm.wchscu.cn/).

CONCLUSIONS

These findings suggest that real-time identification of surgical patients' risk of postoperative pulmonary complications could help personalise intraoperative ventilatory strategies and reduce postoperative pulmonary complications.

Postoperative Gastrointestinal Dysfunction After Neuromuscular Blockade Reversal With Sugammadex Versus Cholinesterase Inhibitors in Patients Undergoing Gastrointestinal Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Postoperative gastrointestinal dysfunction (POGD) commonly occurs following gastrointestinal (GI) surgery and is associated with specific anesthetic agents. Cholinesterase inhibitors employed for reversing neuromuscular blockade have been implicated in development of POGD. Sugammadex, a novel reversal agent, is linked with reduced POGD. However, there is a lack of comprehensive comparative review between these agents regarding their impact on POGD following GI surgery. This study aims to systematically review the effects of sugammadex on POGD compared to cholinesterase inhibitors following GI surgery.

METHODS

MEDLINE, EMBASE, and CENTRAL were searched as of July 2022 to identify articles comparing sugammadex with cholinesterase inhibitors in patients undergoing gastrointestinal surgery, specifically in relation to POGD. Secondary endpoints included length of hospital stay, readmission rates, pulmonary complications, and postoperative morbidity.

RESULTS

From 198 citations, 2 randomized controlled trials (RCTs) and 3 retrospective cohorts with 717 patients receiving sugammadex and 812 patients receiving cholinesterase inhibitors were included. Significantly lower rates of prolonged postoperative ileus (OR .44, 95% CI .25-.77, P < .05, I2 = 56%, low certainty evidence) was observed with sugammadex. No significant difference in any other outcome was observed. Narrative review of readmission data demonstrated no significant difference.

CONCLUSION

The use of sugammadex following gastrointestinal surgery is associated with significantly lower rates of prolonged postoperative ileus compared to cholinesterase inhibitors. However, these do not translate into a significant reduction in length of stay, morbidity, or postoperative nausea and vomiting. Results are limited by the numer of studies included and missing data, more robust RCTs are needed before recommendations can be made.

Increased postoperative complications after laparoscopic gastrectomy in patients with preserved ratio impaired spirometry

BACKGROUND

Preserved ratio impaired spirometry (PRISm), defined as decreased forced expiratory volume in the first second in the setting of normal ratio, is associated with an increased risk of respiratory disease and systemic comorbidities. Unlike severe obstructive pulmonary disease, little is known about the impact of PRISm on short-term outcomes in patients undergoing laparoscopic gastrectomy (LG) and its association with small airway dysfunction (SAD).

METHODS

This study enrolled 830 patients who underwent preoperative spirometry and LG between January 2021 and August 2023. Of these, 228 patients were excluded. Participants were categorized into 3 groups based on their baseline lung function, and postoperative outcomes were subsequently analyzed. Potential associations between postoperative outcomes and various clinical variables were examined using univariate and multivariate analyses.

RESULTS

PRISm was identified in 16.6% of the patients, whereas SAD was present in 20.4%. The incidence of postoperative pulmonary complications (PPCs) was notably higher in the SAD group (20.3% vs 9.8%, P = .002) and the PRISm group (28.0% vs 9.8%, P < .001) than the normal group. Among the 3 groups, pneumonia was the most frequently observed PPC. Multivariate analysis revealed that both SAD (odds ratio [OR], 2.34; 95% CI, 1.30-4.22; P = .005) and PRISm (OR, 3.26; 95% CI, 1.80-5.90; P < .001) independently constituted significant risk factors associated with the occurrence of PPCs. Univariate analysis showed that female was a possible risk factor for PPCs in PRISm group.

CONCLUSION

Our study showed that PRISm and SAD were associated with the increased PPCs in patients undergoing LG for gastric cancer.

The incidence of hypoxemia in dogs recovering from general anesthesia detected with pulse-oximetry and related risk factors

The postoperative period is critical for the development of complications, including hypoxemia. To detect hypoxemia early and provide appropriate care, continuous monitoring of saturation is necessary: pulse oximetry is an easily accessible and simple method for this purpose. However, a SpO2 cut-off value to detect hypoxemia in dogs recovering from general anesthesia is lacking in the veterinary literature. The objectives of this clinical study are to validate the room air SpO2 test (SpAT), to identify a cut-off value to discriminate hypoxemia (Phase 1), and to apply the SpAT to study the incidence of transient postoperative hypoxemia (TPH) (Phase 2) in dogs with healthy lungs recovering from general anesthesia. Phase 1: 87 dogs recovering from general anesthesia with an arterial line were included. After extubation, SpAT was performed simultaneously with arterial blood sampling. A PaO2 < 80 mmHg was considered hypoxemia. Phase 2: 654 dogs were enrolled. They underwent general anesthesia with different ventilation settings for different procedures. After extubation, dogs were classified as hypoxemic if the SpO2 was lower than the cut-off obtained in phase 1. Phase 1 showed that the SpO2 cut-off is < 95% (sensitivity 100%, specificity 97.4%; area under the curve, AUC = 0.996; 95% Confidence Interval = 0.944-1; P<0.0001). In Phase 2, 169 dogs were hypoxemic. Body Condition Score (BCS) > 3/5, dorsal recumbency, FiO2 1, absence of Positive End-Expiratory Pressure (PEEP) had a significant odds ratio to induce TPH (5.8, 1.9, 3.7, 1.7, respectively). These results showed that SpO2 < 95% indicates PaO2 < 80 mmHg in dogs and TPH occurs in up to 28% of cases. Identification of associated risks could be useful to prevent and to increase awareness for monitoring and treatment.

Comparison of lung aeration loss in open abdominal oncologic surgeries after ventilation with electrical impedance tomography-guided PEEP versus conventional PEEP: a pilot feasibility study

BACKGROUND

Existing literature lacks high-quality evidence regarding the ideal intraoperative positive end-expiratory pressure (PEEP) to minimize postoperative pulmonary complications (PPCs). We hypothesized that applying individualized PEEP derived from electrical impedance tomography would reduce the severity of postoperative lung aeration loss, deterioration in oxygenation, and PPC incidence.

METHODS

A pilot feasibility study was conducted on 36 patients who underwent open abdominal oncologic surgery. The patients were randomized to receive individualized PEEP or conventional PEEP at 4 cmH2O. The primary outcome was the impact of individualized PEEP on changes in the modified lung ultrasound score (MLUS) derived from preoperative and postoperative lung ultrasonography. A higher MLUS indicated greater lung aeration loss. The secondary outcomes were the PaO2/FiO2 ratio and PPC incidence.

RESULTS

A significant increase in the postoperative MLUS (12.0 ± 3.6 vs 7.9 ± 2.1, P < 0.001) and a significant difference between the postoperative and preoperative MLUS values (7.0 ± 3.3 vs 3.0 ± 1.6, P < 0.001) were found in the conventional PEEP group, indicating increased lung aeration loss. In the conventional PEEP group, the intraoperative PaO2/FiO2 ratios were significantly lower but not the postoperative ratios. The PPC incidence was not significantly different between the groups. Post-hoc analysis showed the increase in lung aeration loss and deterioration of intraoperative oxygenation correlated with the deviation from the individualized PEEP.

CONCLUSIONS

Individualized PEEP appears to protect against lung aeration loss and intraoperative oxygenation deterioration. The advantage was greater in patients whose individualized PEEP deviated more from the conventional PEEP.

Association of point-of-care lung ultrasound findings with 30-day pulmonary complications after cardiac surgery: A prospective cohort study

Background

Several studies have shown that bedside lung ultrasound findings in postanaesthesia care units (PACUs) and intensive care units (ICUs) correlate with postoperative pulmonary complications(PPCs) after noncardiac major surgery. However, it remains unclear whether lung ultrasound findings can be used as early predictors of PPCs in patients undergoing cardiac surgery. The main aim of our study was to evaluate the relationship between early postoperative point-of-care lung ultrasound findings and PPCs after cardiac surgery.

Methods

Two board-certified physicians performed a point-of-care pulmonary ultrasound on cardiac surgery patients approximately 2 h after the patient was admitted to the ICU. Pulmonary complications occurring within 30 days postoperatively were recorded. Logistic regression modeling was used to analyze the relationship between lung ultrasound findings and PPCs.

Results

PPCs occurred in 61 (30.9 %) of the 197 patients. Lung ultrasound scores(LUS), number of lung consolidation(NLC), and depth of pleural effusion(DPE) were more significant in patients who developed PPCs (P < 0.001). According to the multivariate analysis, NLC≥3(aOR 2.71,95%CI 1.14-6.44; p = 0.024)and DPE >0.95(aOR 3.79,95%CI 1.60-8.99; p = 0.002) were found to be independently associated with PPCs during this study.

Conclusions

Our study demonstrated that DPE >0.95 and NLC ≥3 were associated with PPCs after cardiac surgery based on bedside lung ultrasound findings in the ICU. When these signs manifest perioperatively, the surgeon should be alerted and the necessary steps should be taken, especially if they present simultaneously.

Dexmedetomidine Attenuates Inflammation in Elderly Patients Following Major Hepatobiliary and Pancreatic Surgery: A Randomized Clinical Trial

Background

Dexmedetomidine (Dex) may have anti-inflammatory properties and potentially reduce the incidence of postoperative organ injury.

Objective

To investigate whether Dex protects pulmonary and renal function via its anti-inflammatory effects in elderly patients undergoing prolonged major hepatobiliary and pancreatic surgery.

Design and Setting

Between October 2019 and December 2020, this randomized controlled trial was carried out at a tertiary hospital in Chongqing, China.

Patients

86 patients aged 60-75 who underwent long-duration (> 4 hrs) hepatobiliary and pancreatic surgery without significant comorbidities were enrolled and randomly assigned into two groups at a 1:1 ratio.

Interventions

Patients were given either Dex or an equivalent volume of 0.9% saline (Placebo) with a loading dose of 1 μg kg-1 for 10 min, followed by 0.5 μg kg-1 hr-1 for maintenance until the end of surgery.

Main Outcome Measures

The changes in serum concentrations of interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) were primary outcomes.

Results

At one hour postoperatively, serum IL-6 displayed a nine-fold increase (P<0.05) in the Placebo group. Administration of Dex decreased IL-6 to 278.09 ± 45.43 pg/mL (95% CI: 187.75 to 368.43) compared to the Placebo group (P=0.019; 432.16 ± 45.43 pg/mL, 95% CI: 341.82 to 522.50). However, no significant differences in TNF-α were observed between the two groups. The incidence of postoperative acute kidney injury was twice as high in the Placebo group (9.30%) compared to the Dex group (4.65%), and the incidence of postoperative acute lung injury was 23.26% in the Dex group, lower than that in the Placebo group (30.23%), although there was no statistical significance between the two groups.

Conclusion

Dex administration in elderly patients undergoing major hepatobiliary and pancreatic surgery reduces inflammation and potentially protects kidneys and lungs.

Registration

Chinese Clinical Trials Registry, identifier: ChiCTR1900024162, on 28 June 2019.

Risk factors for pulmonary complications after colorectal cancer surgery: a Japanese multicenter study

PURPOSE

Pulmonary complications (PC) are a serious condition with a 20% mortality rate. However, few reports have examined risk factors for PC after colorectal surgery. This study investigated the frequency, characteristics, and risk factors for PC after colorectal cancer surgery.

METHODS

Between January 2016 and December 2022, we retrospectively reviewed 3979 consecutive patients who underwent colorectal cancer surgery in seven participating hospitals. Patients were divided into patients who experienced PC (PC group, n = 54) and patients who did not (non-PC group, n = 3925). Clinical and pathological features were compared between groups.

RESULTS

Fifty-four patients (1.5%) developed PC, of whom 2 patients (3.7%) died due to PC. Age was greater (80 years vs 71 years; p < 0.001), frequency of chronic obstructive pulmonary distress was greater (9.3% vs 3.2%; p = 0.029), performance status was poorer (p < 0.001), the proportion of underweight was higher (42.6% vs 13.4%, p < 0.001), frequency of open surgery was greater (24.1% vs 9.3%; p < 0.001), and blood loss was greater (40 mL vs 22 mL; p < 0.001) in the PC group. Multivariate analysis revealed male sex (odds ratio (OR) 2.165, 95% confidence interval (CI) 1.176-3.986; p = 0.013), greater age (OR 3.180, 95%CI 1.798-5.624; p < 0.001), underweight (OR 3.961, 95%CI 2.210-7.100; p < 0.001), and poorer ASA-PS (OR 3.828, 95%CI 2.144-6.834; p < 0.001) as independent predictors of PC.

CONCLUSION

Our study revealed male sex, greater age, underweight, and poorer ASA-PS as factors associated with development of PC, and suggested that pre- and postoperative rehabilitation and pneumonia control measures should be implemented for patients at high risk of PC.

Does coronavirus disease 2019 history alone increase the risk of postoperative pulmonary complications after surgery? Prospective observational study using serology assessment

BACKGROUND

Concern exists about the increasing risk of postoperative pulmonary complications in patients with a history of coronavirus disease 2019 (COVID-19).

OBJECTIVE

We conducted a prospective observational study that compared the incidence of postoperative pulmonary complications in patients with and without a history of COVID-19.

METHODS

From August 2022 to November 2022, 244 adult patients undergoing major non-cardiac surgery were enrolled and allocated either to history or no history of COVID-19 groups. For patients without a history of confirming COVID-19 diagnosis, we tested immunoglobulin G to nucleocapsid antigen of SARS-CoV-2 for serology assessment to identify undetected infection. We compared the incidence of postoperative pulmonary complications, defined as a composite of atelectasis, pleural effusion, pulmonary edema, pneumonia, aspiration pneumonitis, and the need for additional oxygen therapy according to a COVID-19 history.

RESULTS

After excluding 44 patients without a COVID-19 history who were detected as seropositive, 200 patients were finally enrolled in this study, 100 in each group. All subjects with a COVID-19 history experienced no or mild symptoms during infection. The risk of postoperative pulmonary complications was not significantly different between the groups according to the history of COVID-19 (24.0% vs. 26.0%; odds ratio, 0.99; 95% confidence interval, 0.71-1.37; P-value, 0.92). The incidence of postoperative pulmonary complications was also similar (27.3%) in excluded patients owing to being seropositive.

CONCLUSION

Our study showed patients with a history of no or mild symptomatic COVID-19 did not show an increased risk of PPCs compared to those without a COVID-19 history. Additional precautions may not be needed to prevent PPCs in those patients.

Risk factors for postoperative pulmonary complications in elderly patients undergoing video-assisted thoracoscopic surgery lobectomy under general anesthesia: a retrospective study

BACKGROUND

The objective of this study is to identify and evaluate the risk factors associated with the development of postoperative pulmonary complications (PPCs) in elderly patients undergoing video-assisted thoracoscopic surgery lobectomy under general anesthesia.

METHODS

The retrospective study consecutively included elderly patients (≥ 70 years old) who underwent thoracoscopic lobectomy at Xuanwu Hospital of Capital Medical University from January 1, 2018 to August 31, 2023. The demographic characteristics, the preoperative, intraoperative and postoperative parameters were collected and analyzed using multivariate logistic regression to identify the prediction of risk factors for PPCs.

RESULTS

322 patients were included for analysis, and 115 patients (35.7%) developed PPCs. Multifactorial regression analysis showed that ASA ≥ III (P = 0.006, 95% CI: 1.230 ∼ 3.532), duration of one-lung ventilation (P = 0.033, 95% CI: 1.069 ∼ 4.867), smoking (P = 0.027, 95% CI: 1.072 ∼ 3.194) and COPD (P = 0.015, 95% CI: 1.332 ∼ 13.716) are independent risk factors for PPCs after thoracoscopic lobectomy in elderly patients.

CONCLUSION

Risk factors for PPCs are ASA ≥ III, duration of one-lung ventilation, smoking and COPD in elderly patients over 70 years old undergoing thoracoscopic lobectomy. It is necessary to pay special attention to these patients to help optimize the allocation of resources and enhance preventive efforts.

Effects of non-invasive respiratory support in post-operative patients: a systematic review and network meta-analysis

BACKGROUND

Re-intubation secondary to post-extubation respiratory failure in post-operative patients is associated with increased patient morbidity and mortality. Non-invasive respiratory support (NRS) alternative to conventional oxygen therapy (COT), i.e., high-flow nasal oxygen, continuous positive airway pressure, and non-invasive ventilation (NIV), has been proposed to prevent or treat post-extubation respiratory failure. Aim of the present study is assessing the effects of NRS application, compared to COT, on the re-intubation rate (primary outcome), and time to re-intubation, incidence of nosocomial pneumonia, patient discomfort, intensive care unit (ICU) and hospital length of stay, and mortality (secondary outcomes) in adult patients extubated after surgery.

METHODS

A systematic review and network meta-analysis of randomized and non-randomized controlled trials. A search from Medline, Embase, Scopus, Cochrane Central Register of Controlled Trials, and Web of Science from inception until February 2, 2024 was performed.

RESULTS

Thirty-three studies (11,292 patients) were included. Among all NRS modalities, only NIV reduced the re-intubation rate, compared to COT (odds ratio 0.49, 95% confidence interval 0.28; 0.87, p = 0.015, I2 = 60.5%, low certainty of evidence). In particular, this effect was observed in patients receiving NIV for treatment, while not for prevention, of post-extubation respiratory failure, and in patients at high, while not low, risk of post-extubation respiratory failure. NIV reduced the rate of nosocomial pneumonia, ICU length of stay, and ICU, hospital, and long-term mortality, while not worsening patient discomfort.

CONCLUSIONS

In post-operative patients receiving NRS after extubation, NIV reduced the rate of re-intubation, compared to COT, when used for treatment of post-extubation respiratory failure and in patients at high risk of post-extubation respiratory failure.

Can resistance prehabilitation training bring additional benefits in valvular cardiac surgery? protocol for a randomized controlled trial

INTRODUCTION

Cardiovascular diseases (CVD) are a group of illnesses that include coronary heart disease, cerebrovascular disease, congenital heart disease and deep vein thrombosis. Major surgery is often chosen as the treatment of choice for CVD. The concept of fast-track rehabilitation after surgery appeared in the 1970s. Participation in these exercise-based prehabilitation programmes may decrease postoperative complications and length of hospital stay. The primary aim of the present study is to evaluate whether the implementation of an additional resistance training (RT) prehabilitation protocol within cardiac exercises based prehabilitation can reduce intensive care unit (ICU) length of stay, postoperative complications and hospital length of stay (LOS).

METHODS

A protocol of a prospective, parallel, randomised clinical trial includes 96 adult patients diagnosed with valvular pathology and who have been scheduled for surgery. The participants will be randomly assigned to two groups of 48. Control group will be treated with ventilatory and strengthening of respiratory muscles, and aerobic exercise. Experimental group, in addition, will be treated with RT of peripheral muscles. Both hospital stay and ICU stay will be assessed as main variables. Other secondary variables such as exercise capacity, quality of life and respiratory values will also be assessed. Quantitative variables will be analysed with a T-Test or ANOVA, or Mann Witney if the distribution is non-parametric.

RESULTS AND CONCLUSION

This will be the first controlled clinical study focused on adding strength exercise as an additional treatment during prehabilitation. The results of this study will focus on helping to improve rehabilitation and prehabilitation protocols, considering that it is essential to maintain pulmonary training, as well as the inclusion of peripheral exercises that help people with heart disease to be in a better physical condition in order to increase their participation and sense of quality of life.

Association of Mechanical Energy and Power with Postoperative Pulmonary Complications in Lung Resection Surgery: A Post Hoc Analysis of Randomized Clinical Trial Data

BACKGROUND

Mechanical power (MP), the rate of mechanical energy (ME) delivery, is a recently introduced unifying ventilator parameter consisting of tidal volume, airway pressures, and respiratory rates, which predicts pulmonary complications in several clinical contexts. However, ME has not been previously studied in the perioperative context, and neither parameter has been studied in the context of thoracic surgery utilizing one-lung ventilation.

METHODS

The relationships between ME variables and postoperative pulmonary complications were evaluated in this post hoc analysis of data from a multicenter randomized clinical trial of lung resection surgery conducted between 2020 and 2021 (n = 1,170). Time-weighted average MP and ME (the area under the MP time curve) were obtained for individual patients. The primary analysis was the association of time-weighted average MP and ME with pulmonary complications within 7 postoperative days. Multivariable logistic regression was performed to examine the relationships between energy variables and the primary outcome.

RESULTS

In 1,055 patients analyzed, pulmonary complications occurred in 41% (431 of 1,055). The median (interquartile ranges) ME and time-weighted average MP in patients who developed postoperative pulmonary complications versus those who did not were 1,146 (811 to 1,530) J versus 924 (730 to 1,240) J (P < 0.001), and 6.9 (5.5 to 8.7) J/min versus 6.7 (5.2 to 8.5) J/min (P = 0.091), respectively. ME was independently associated with postoperative pulmonary complications (ORadjusted, 1.44 [95% CI, 1.16 to 1.80]; P = 0.001). However, the association between time-weighted average MP and postoperative pulmonary complications was time-dependent, and time-weighted average MP was significantly associated with postoperative pulmonary complications in cases utilizing longer periods of mechanical ventilation (210 min or greater; ORadjusted, 1.46 [95% CI, 1.11 to 1.93]; P = 0.007). Normalization of ME and time-weighted average MP either to predicted body weight or to respiratory system compliance did not alter these associations.

CONCLUSIONS

ME and, in cases requiring longer periods of mechanical ventilation, MP were independently associated with postoperative pulmonary complications in thoracic surgery.

EDITOR’S PERSPECTIVE

Retrospective Analysis of Postoperative Nonhepatic Outcomes Following Major Liver Resection

Background Liver surgery is a major and challenging procedure for the surgeon, the anesthetist, and the patient. The objective of this study was to evaluate the postoperative nonhepatic complications of patients undergoing liver resection surgery with perioperative factors. Methods We retrospectively analyzed 79 patients who underwent liver resection surgeries at the Shaukat Khanum Memorial Cancer Hospital and Research Centre in Lahore, Pakistan, from July 2015 to December 2022. Results The mean age at the time of surgery was 53 years (range: 3-77 years), and the mean BMI was 26.43 (range: 15.72-38.0 kg/m2). Of the total patients, 44.3 % (n = 35) had no comorbidities, 26.6% (n=21) had one comorbidity, and 29.1% (n=23) had two or more comorbidities. Patients in whom the blood loss was more than 375 ml required postoperative oxygen inhalation with a significant relative risk of 2.6 (p=0.0392) and an odds ratio of 3.5 (p=0.0327). Similarly, patients who had a surgery time of more than five hours stayed in the hospital for more than seven days, with a statistically significant relative risk of 2.7 (p=0.0003) and odds ratio of 7.64 (p=0.0001). The duration of surgery was also linked with the possibility of requiring respiratory support, with a relative risk of 5.0 (p=0.0134) and odds ratio of 5.73 (p=0.1190). Conclusion Patients in our cohort who had a prolonged duration of surgery received an increased amount of fluids, and a large volume of blood loss was associated with prolonged stay in the ICU (>2 days), hospital admission (>7 days), ICU readmission, and increased incidence of cardiorespiratory, neurological, and renal disturbances postoperatively.

Association of remaining tooth number with postoperative respiratory complications in heart valve surgery patients

OBJECTIVES

This study examined the association between the number of remaining teeth and the incidence of postoperative respiratory complications in patients undergoing heart valve surgery.

METHODS

We retrospectively enrolled 157 patients who underwent heart valve surgery between April 2010 and March 2019. Data on patient characteristics including systemic and oral conditions were extracted and postoperative respiratory complications were set as outcomes. Patients were divided into two groups according to the number of remaining teeth (≥20, <20). After adjusting for confounding factors with propensity scoring, logistic regression analysis was performed to examine the association of remaining teeth number with the incidence of postoperative respiratory complications. In addition, subgroup analysis was performed by stratifying the data into quintiles based on the propensity score.

RESULTS

Univariate analysis showed significant differences between the two groups in factors, including age, past cardiac surgery experience, New York Heart Association functional classification class IV, denture use, tooth extraction before surgery, occlusal support, and periodontitis. Logistic regression analysis showed that patients with <20 remaining teeth had a significantly higher incidence of postoperative respiratory complications than those with ≥20 remaining teeth, with an odds ratio of 29.800 (p = 0.004). Subgroup analysis showed that the odds ratio for the patients with <20 remaining teeth was 9.000 (p = 0.038).

CONCLUSIONS

The results suggest that heart valve surgery patients shall get attention on oral disease prevention by dental care practitioners to maintain a sufficient number of teeth for the prevention of postoperative respiratory complications.

Pro-Con Debate: Universal Versus Selective Continuous Monitoring of Postoperative Patients

In this Pro-Con commentary article, we discuss use of continuous physiologic monitoring for clinical deterioration, specifically respiratory depression in the postoperative population. The Pro position advocates for 24/7 continuous surveillance monitoring of all patients starting in the postanesthesia care unit until discharge from the hospital. The strongest arguments for universal monitoring relate to inadequate assessment and algorithms for patient risk. We argue that the need for hospitalization in and of itself is a sufficient predictor of an individual's risk for unexpected respiratory deterioration. In addition, general care units carry the added risk that even the most severe respiratory events will not be recognized in a timely fashion, largely due to higher patient to nurse staffing ratios and limited intermittent vital signs assessments (e.g., every 4 hours). Continuous monitoring configured properly using a "surveillance model" can adequately detect patients' respiratory deterioration while minimizing alarm fatigue and the costs of the surveillance systems. The Con position advocates for a mixed approach of time-limited continuous pulse oximetry monitoring for all patients receiving opioids, with additional remote pulse oximetry monitoring for patients identified as having a high risk of respiratory depression. Alarm fatigue, clinical resource limitations, and cost are the strongest arguments for selective monitoring, which is a more targeted approach. The proponents of the con position acknowledge that postoperative respiratory monitoring is certainly indicated for all patients, but not all patients need the same level of monitoring. The analysis and discussion of each point of view describes who, when, where, and how continuous monitoring should be implemented. Consideration of various system-level factors are addressed, including clinical resource availability, alarm design, system costs, patient and staff acceptance, risk-assessment algorithms, and respiratory event detection. Literature is reviewed, findings are described, and recommendations for design of monitoring systems and implementation of monitoring are described for the pro and con positions.

Trends in the Utilization of Multiorgan Support Among Adults Undergoing High-risk Cardiac Surgery in the United States

OBJECTIVES

To examine trends in the prevalence of multiorgan dysfunction (MODS), utilization of multi-organ support (MOS), and mortality among patients undergoing cardiac surgery with MODS who received MOS in the United States.

DESIGN

Retrospective cohort study.

SETTING

183 hospitals in the Premier Healthcare Database.

PARTICIPANTS

Adults ≥18 years old undergoing high-risk elective or non-elective cardiac surgery.

INTERVENTIONS

none.

MEASUREMENTS AND MAIN RESULTS

The exposure was time (consecutive calendar quarters) January 2008 and June 2018. We analyzed hospital data using day-stamped hospital billing codes and diagnosis and procedure codes to assess MODS prevalence, MOS utilization, and mortality. Among 129,102 elective and 136,190 non-elective high-risk cardiac surgical cases across 183 hospitals, 10,001 (7.7%) and 21,556 (15.8%) of patients developed MODS, respectively. Among patients who experienced MODS, 2,181 (22%) of elective and 5,425 (25%) of non-elective cardiac surgical cases utilized MOS. From 2008-2018, MODS increased in both high-risk elective and non-elective cardiac surgical cases. Similarly, MOS increased in both high-risk elective and non-elective cardiac surgical cases. As a component of MOS, mechanical circulatory support (MCS) increased over time. Over the study period, risk-adjusted mortality, in patients who developed MODS receiving MOS, increased in high-risk non-elective cardiac surgery and decreased in high-risk elective cardiac surgery, despite increasing MODS prevalence and MOS utilization (p<0.001).

CONCLUSIONS

Among patients undergoing high-risk cardiac surgery in the United States, MODS prevalence and MOS utilization (including MCS) increased over time. Risk-adjusted mortality trends differed in elective and non-elective cardiac surgery. Further research is necessary to optimize outcomes among patients undergoing high-risk cardiac surgery.

Restoration of Pulmonary Compliance after Laparoscopic Gynecologic Surgery Using a Recruitment Maneuver

BACKGROUND/OBJECTIVES

This study aimed to investigate the hypothesis that an alveolar recruitment maneuver can restore lung compliance to initial values after laparoscopic gynecological surgery.

METHODS

A total of 31 patients who underwent laparoscopic gynecological surgery were enrolled. Protective mechanical ventilation was applied, and the radial artery was catheterized in all patients. An alveolar recruitment maneuver (incremental and decremental positive end-expiratory pressure) was applied ten minutes after the release of pneumoperitoneum. The respiratory mechanics and blood gas results were recorded at eight different time points: after induction of anesthesia (T1), in the lithotomy position (T2), in the Trendelenburg position (T3), 10 and 90 min after insufflation of carbon dioxide (T4 and T5), in the supine position (T6), after desufflation (T7), and 10 min after an alveolar recruitment maneuver at the end of surgery (T8).

RESULTS

Pneumoperitoneum and the Trendelenburg position caused a decline of 15 units in compliance (T7 vs. T1; p < 0.05) compared to baseline. After the alveolar recruitment maneuver, compliance increased by 17.5% compared with the mean value of compliance at time T1 (T8 vs. T1; p < 0.05). The recruitment maneuver had favorable results in patients with low initial compliance (41.5 mL/cmH2O, IQR: 9.75 mL/cmH2O), high Body Mass Index 30.32 kg/m2 (IQR: 1.05 kg/m2), and high initial plateau airway pressure (16.5 cmH2O, IQR: 0.75 cmH2O).

CONCLUSIONS

Lung compliance does not return to initial values after performing laparoscopic gynecological procedures. However, after the release of pneumoperitoneum, an alveolar recruitment maneuver is beneficial as it improves compliance and gas exchange.

Modified Frailty Index Associates With Transoral Robotic Surgery Complications and Survival: A National Database Study

OBJECTIVE

The modified frailty index (mFI-5) is a National Surgical Quality Improvement Program-derived 5-factor index that has been proven to reflect frailty and predict morbidity and mortality. We hypothesize that mFI-5 is a valid predictive measure in the transoral robotic surgery (TORS) population.

METHODS

Retrospective study utilizing the TriNetX US-collaborative health records network querying for TORS patients. Cohorts were stratified by mFI-5 score which uses five ICD-10 codes: nonindependent functional status, hypertension, obstructive respiratory disease, heart failure, and diabetes mellitus. Cohorts were matched by age using propensity score matching. Outcome measures included survival, infection, pneumonia, tracheostomy dependence, and percutaneous endoscopic gastrostomy dependence. Reported odds ratios were normalized to mFI-5 = 0.

RESULTS

A total of 9,081 patients were included in the final analysis. Greater mFI-5 scores predicted decreased survival and increased incidence of postoperative infection and pneumonia. Odds of 5-year mortality were 1.93 (p = 0.0003) for mFI-5 = 2 and 1.90 (p = 0.0002) for mFI-5 = 3. Odds of 2-year mortality were 1.25 (p = 0.0125) for mFI-5 = 1, 1.58 (p = 0.0002) for mFI-5 = 2, and 1.87 (p = 0.003) for mFI-5 = 3. Odds of postoperative infection were 1.51 (p = 0.02) for mFI-5 = 2 and 1.78 (p = 0.05) for mFI-5 = 3. Two-year odds of developing pneumonia were 1.69 (p = 0.0001) for mFI-5 = 2 and 2.84 (p < 0.0001) for mFI-5 = 3. Two-month odds of pneumonia were 1.50 (p = 0.0259) for mFI-5 = 2 and 2.55 (p = 0.0037) for mFI-5 = 3. mFI-5 = 4 or 5 had too few patients to analyze. Using polynomial regression to model age versus incident 5-year post-TORS death (R2 = 0.99), mFI-5 scores better predicted survival than age alone.

CONCLUSION

This study demonstrates that mFI-5 predicts mortality, pneumonia, and postoperative infection independently of age.

LEVEL OF EVIDENCE

4 Laryngoscope, 2024.

Comparison of Hemodynamic Parameters Based on the Administration of Remimazolam or Sevoflurane in Patients under General Anesthesia in the Beach Chair Position: A Single-Blinded Randomized Controlled Trial

Background: We aimed to evaluate whether the administration of remimazolam as a maintenance agent for general anesthesia affects the occurrence of hypotension compared with sevoflurane when switching to the beach chair position (BCP). Methods: We conducted a prospective randomized controlled trial from June 2023 to October 2023 in adult patients undergoing orthopedic surgery under general anesthesia in the BCP. A total of 78 participants were randomly allocated to the remimazolam (R) or sevoflurane (S) groups. The primary outcome was the incidence of hypotension that occurred immediately after switching to a BCP. The secondary outcomes included differences between the study groups in perioperative blood pressure (BP), heart rate (HR), endotracheal tube extubation time, postoperative complications, and hospital length of stay (LOS). Results: The incidence of hypotension immediately after switching to a BCP was significantly higher in the S group. The risk factors associated with hypotension included sevoflurane administration and a high baseline systolic BP. In the receiver operating characteristic curve analysis for the occurrence of hypotension after the transition to a BCP, the cutoff value for systolic BP was 142 mmHg. The perioperative BP and HR were higher in the R group at several timepoints. Postoperative endotracheal tube extubation time was shorter in the R group. There were no significant differences in the postoperative complications or hospital LOS between the two groups. Conclusions: Remimazolam should be considered as an anesthetic agent to prevent hypotension when switching to BCP, and hypotension may occur frequently in patients with high baseline BP.

Noninvasive respiratory support in the perioperative setting: a narrative review

The application of preoperative noninvasive respiratory support (NRS) has been expanding with increasing recognition of its potential role in this setting as a physiological optimization for patients with a high risk of developing atelectasis and postoperative pulmonary complications (PPC). The increased availability of high-performance anesthesia ventilator machines providing an easy way for NRS support in patients with reduced lung function should not be under-evaluated. This support can reduce hypoxia, restore lung volumes and theoretically reduce atelectasis formation after general anesthesia. Therapeutic purposes should also be considered in the perioperative setting, such as preoperative NRS to optimize treatment of patients' pre-existing diseases, e.g., sleep-disordered breathing. Finally, the recent guidelines for airway management suggest preoperative NRS application before anesthesia induction in difficult airway management to prolong the time needed to secure the airway with an orotracheal tube. This narrative review aims to revise all these aspects and to provide some practical notes to maximize the efficacy of perioperative noninvasive respiratory support.

Single-Lung Ventilation in Infants for Surgical Repair of Coarctation of The Aorta Without Cardiopulmonary Bypass

OBJECTIVE

To investigate the effect of improving the operative field and postoperative atelectasis of single-lung ventilation (SLV) in the surgical repair of coarctation of the aorta (CoA) in infants without the use of cardiopulmonary bypass (CPB).

METHODS

This was a retrospective cohort study. The clinical data of 28 infants (aged 1 to 4 months, weighing between 4.2 and 6 kg) who underwent surgical repair of CoA without CPB from January 2019 to May 2022 were analyzed. Fourteen infants received SLV with a bronchial blocker (Group S), and the other 14 infants received routine endotracheal intubation and bilateral lung ventilation (Group R).

RESULTS

In comparison to Group R, Group S exhibited improved exposure of the operative field, a lower postoperative atelectasis score (P<0.001), reduced prevalence of hypoxemia (P=0.01), and shorter durations of operation, mechanical ventilation, and ICU stay (P=0.01, P<0.001, P=0.03). There was no difference in preoperative information or perioperative respiratory and circulatory indicators before SLV, 10 minutes after SLV, and 10 minutes after the end of SLV between the two groups (P>0.05). Intraoperative bleeding, intraoperative positive end-expiratory pressure (PEEP), and systolic pressure gradient across the coarctation after operation were also not different between the two groups (P>0.05).

CONCLUSION

This study demonstrates that employing SLV with a bronchial blocker is consistent with enhanced operative field, reduced operation duration, lower prevalence of intraoperative hypoxemia, and fewer postoperative complications during the surgical repair of CoA in infants without the use of CPB.

Positive end-expiratory pressure and the incidence of postoperative pulmonary complications in patients undergoing general anaesthesia

AIM OF THE STUDY

To evaluate the effect of intraoperative positive end-expiratory pressure and driving pressure on the development of postoperative pulmonary complications.

METHOD

The prospective study included 83 patients undergoing abdominal surgery and receiving general anaesthesia. Patients were divided into two groups: with low intraoperative positive end-expiratory pressure (0-2cm H2O) and with high intraoperative positive end-expiratory pressure (8-10cm H2O). The primary endpoint is the development of postoperative pulmonary complications during follow-up.

RESULTS

The incidence of postoperative pulmonary complications in the group of low intraoperative positive end-expiratory pressure was 9.8%, while in the group of high positive end-expiratory pressure was 7.1% (p = 0.6), demonstrating that high positive end-expiratory pressure used during general anaesthesia does not affect the frequency of complications (odds ratio = 0.71, p = 0.6). In the multivariate analysis that controls for all confounders, driving pressure resulted in a significant and independent risk factor for complications.

CONCLUSION

High intraoperative positive end-expiratory pressure does not affect the frequency of postoperative pulmonary complications. The increase in driving pressure is a risk factor for complications. Positive end-expiratory pressure is easily implemented, and its use does not result in significant economic costs.

Association of ketamine use during procedural sedation with oxygen desaturation and healthcare utilisation: a multicentre retrospective hospital registry study

BACKGROUND

We investigated the effects of ketamine on desaturation and the risk of nursing home discharge in patients undergoing procedural sedation by anaesthetists.

METHODS

We included adult patients who underwent procedures under monitored anaesthetic care between 2005 and 2021 at two academic healthcare networks in the USA. The primary outcome was intraprocedural oxygen desaturation, defined as oxygen saturation <90% for ≥2 consecutive minutes. The co-primary outcome was a nursing home discharge.

RESULTS

Among 234,170 included patients undergoing procedural sedation, intraprocedural desaturation occurred in 5.6% of patients who received ketamine vs 5.2% of patients who did not receive ketamine (adjusted odds ratio [ORadj] 1.22, 95% confidence interval [CI] 1.15-1.29, P<0.001; adjusted absolute risk difference [ARDadj] 1%, 95% CI 0.7-1.3%, P<0.001). The effect was magnified by age >65 yr, smoking, or preprocedural ICU admission (P-for-interaction <0.001, ORadj 1.35, 95% CI 1.25-1.45, P<0.001; ARDadj 2%, 95% CI 1.56-2.49%, P<0.001), procedural risk factors (upper endoscopy of longer than 2 h; P-for-interaction <0.001, ORadj 2.91, 95% CI 1.85-4.58, P<0.001; ARDadj 16.2%, 95% CI 9.8-22.5%, P<0.001), and high ketamine dose (P-for-trend <0.001, ORadj 1.61, 95% CI, 1.43-1.81 for ketamine >0.5 mg kg-1). Concomitant opioid administration mitigated the risk (P-for-interaction <0.001). Ketamine was associated with higher odds of nursing home discharge (ORadj 1.11, 95% CI 1.02-1.21, P=0.012; ARDadj 0.25%, 95% CI 0.05-0.46%, P=0.014).

CONCLUSIONS

Ketamine use for procedural sedation was associated with an increased risk of oxygen desaturation and discharge to a nursing home. The effect was dose-dependent and magnified in subgroups of vulnerable patients.

Effect of incremental PEEP titration on postoperative pulmonary complications in patients undergoing emergency laparotomy: a randomized controlled trial

Postoperative pulmonary complications (PPC) has a significant negative impact and are associated with increased length of hospital stay and cost of care. Emergency surgery is a well-established risk factor for PPC. Previous studies reported that personalized positive end-expiratory pressure (PEEP) might reduce postoperative atelectasis and postoperative pulmonary complications. N = 168 adult patients undergoing major emergency laparotomy under general anesthesia were recruited in this study. A minimum driving pressure based incremental PEEP titration was compared to a fixed PEEP of 5 cmH2O. The primary outcome was PPC up to postoperative day 7. The mean (standard deviation) of the recruited patients was 41.7(16.1)y, and 48.8% (82 of 168 patients) were female. The risk of PPC at postoperative day 7 was similar in both the study groups [Relative risk (RR) (95% Confidence interval, CI) 0.81 (0.58, 1.13); p = 0.25]. In addition, the incidence of intraoperative hypotension [p = 0.75], oxygen-free days at day 28 [p = 0.27], duration of postoperative hospital stay [p = 0.50], length of postoperative intensive care unit stay [p = 0.28], and in-hospital mortality [p = 0.38] were similar in two groups. Incidence of PPC was not reduced with the use of an individualized PEEP strategy based on lowest driving pressure. However, the incidence of hypotension and bradycardia was also not increased with titrated PEEP.Trial Registration: www.ctri.nic.in ; CTRI/2020/12/029765.

A predictive model for post-thoracoscopic surgery pulmonary complications based on the PBNN algorithm

We constructed an early prediction model for postoperative pulmonary complications after thoracoscopic surgery using machine learning and deep learning algorithms. The artificial intelligence prediction models were built in Python, primarily using artificial intelligencealgorithms including both machine learning and deep learning algorithms. Correlation analysis showed that postoperative pulmonary complications were positively correlated with age and surgery duration, and negatively correlated with serum albumin. Using the light gradient boosting machine(LGBM) algorithm, weighted feature engineering revealed that single lung ventilation duration, history of smoking, surgery duration, ASA score, and blood glucose were the main factors associated with postoperative pulmonary complications. Results of artificial intelligence algorithms for predicting pulmonary complications after thoracoscopy in the test group: In terms of accuracy, the two best algorithms were Logistic Regression (0.831) and light gradient boosting machine(0.827); in terms of precision, the two best algorithms were Gradient Boosting (0.75) and light gradient boosting machine (0.742); in terms of recall, the three best algorithms were gaussian naive bayes (0.581), Logistic Regression (0.532), and pruning Bayesian neural network (0.516); in terms of F1 score, the two best algorithms were LogisticRegression (0.589) and pruning Bayesian neural network (0.566); and in terms of Area Under Curve(AUC), the two best algorithms were light gradient boosting machine(0.873) and pruning Bayesian neural network (0.869). The results of this study suggest that pruning Bayesian neural network (PBNN) can be used to assess the possibility of pulmonary complications after thoracoscopy, and to identify high-risk groups prior to surgery.

Postoperative pulmonary complications in patients undergoing upper abdominal surgery: risk factors and predictive models

Postoperative pulmonary complications (PPCs) are unexpected disorders that occur up to 30 days after surgery, affecting the patient's clinical status and requiring therapeutic intervention. Therefore, it becomes important to assess the patient preoperatively, as many of these complications can be minimized with proper perioperative strategies following a thorough preoperative checkup. Herein, we describe the PPCs and risk factors associated with developing PPCs in patients undergoing upper abdominal surgery. Additionally, we compared the accuracy of the American Society of Anaesthesiologists (ASA) score, the Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) score, the 6-Minute Walk Test (6MWT), and spirometry in predicting PPCs. Consenting patients (>18 years) undergoing elective upper abdominal surgery were recruited from November 2021 to April 2023. Clinical history was noted. Spirometry and 6MWT were both performed. Pre-operative ASA and ARISCAT scores were recorded. Postoperative follow-up was conducted to assess respiratory symptoms and the occurrence of PPC. PPC was defined as per EPCO guidelines. A total of 133 patients were recruited, predominantly male. A total of 27 (20.3%) patients developed PPCs. A total of 14 (10.5%) patients had more than one PPC. The most common PPCs developed were pleural effusion (11.3%), respiratory failure (7.5%), and pneumonia (4.5%). We obtained ten statistically significant associated variables on univariable analysis, viz obstructive airway disease (p=0.002), airflow limitation (p=0.043), chest radiography (p<0.001), albumin (p=0.30), blood urea nitrogen (BUN) (p=0.029), aspartate aminotransferase (p=0.019), alanine aminotransferase (p=0.009), forced expiratory volume in one second/forced vital capacity ratio (p=0.006), duration of surgery (p<0.001), and ASA score (p=0.012). On multivariable regression analysis, abnormal chest radiograph [odds ratio: 8.26; (95% confidence interval: 2.58-25.43), p<0.001], BUN [1.05; (1.00-1.09), p=0.033], and duration of surgery [1.44; (1.18-1.76), p<0.001] were found to be independently associated with PPC. The ASA score was found to have better predictive power for the development of PPCs compared to the ARISCAT score but is of poor clinical significance. Additionally, 6MWD and spirometry results were found to lack any meaningful predictive power for PPC. To conclude, preoperative evaluation of the chest radiograph, BUN, and duration of surgery are independently associated with developing PPCs. The ASA score performs better than the ARISCAT score in identifying patients at a higher risk of developing PPCs and implementing preventive measures.

Effects of Intra-operative Cardiopulmonary Variability On Post-operative Pulmonary Complications in Major Non-cardiac Surgery: A Retrospective Cohort Study

Intraoperative cardiopulmonary variables are well-known predictors of postoperative pulmonary complications (PPC), traditionally quantified by median values over the duration of surgery. However, it is unknown whether cardiopulmonary instability, or wider intra-operative variability of the same metrics, is distinctly associated with PPC risk and severity. We leveraged a retrospective cohort of adults (n = 1202) undergoing major non-cardiothoracic surgery. We used multivariable logistic regression to evaluate the association of two outcomes (1)moderate-or-severe PPC and (2)any PPC with two sets of exposure variables- (a)variability of cardiopulmonary metrics (inter-quartile range, IQR) and (b)median intraoperative cardiopulmonary metrics. We compared predictive ability (receiver operating curve analysis, ROC) and parsimony (information criteria) of three models evaluating different aspects of the intra-operative cardiopulmonary metrics: Median-based: Median cardiopulmonary metrics alone, Variability-based: IQR of cardiopulmonary metrics alone, and Combined: Medians and IQR. Models controlled for peri-operative/surgical factors, demographics, and comorbidities. PPC occurred in 400(33%) of patients, and 91(8%) experienced moderate-or-severe PPC. Variability in multiple intra-operative cardiopulmonary metrics was independently associated with risk of moderate-or-severe, but not any, PPC. For moderate-or-severe PPC, the best-fit predictive model was the Variability-based model by both information criteria and ROC analysis (area under the curve, AUCVariability-based = 0.74 vs AUCMedian-based = 0.65, p = 0.0015; AUCVariability-based = 0.74 vs AUCCombined = 0.68, p = 0.012). For any PPC, the Median-based model yielded the best fit by information criteria. Predictive accuracy was marginally but not significantly higher for the Combined model (AUCCombined = 0.661) than for the Median-based (AUCMedian-based = 0.657, p = 0.60) or Variability-based (AUCVariability-based = 0.649, p = 0.29) models. Variability of cardiopulmonary metrics, distinct from median intra-operative values, is an important predictor of moderate-or-severe PPC.

Individualised, perioperative open-lung ventilation strategy during one-lung ventilation (iPROVE-OLV): a multicentre, randomised, controlled clinical trial

BACKGROUND

It is uncertain whether individualisation of the perioperative open-lung approach (OLA) to ventilation reduces postoperative pulmonary complications in patients undergoing lung resection. We compared a perioperative individualised OLA (iOLA) ventilation strategy with standard lung-protective ventilation in patients undergoing thoracic surgery with one-lung ventilation.

METHODS

This multicentre, randomised controlled trial enrolled patients scheduled for open or video-assisted thoracic surgery using one-lung ventilation in 25 participating hospitals in Spain, Italy, Turkey, Egypt, and Ecuador. Eligible adult patients (age ≥18 years) were randomly assigned to receive iOLA or standard lung-protective ventilation. Eligible patients (stratified by centre) were randomly assigned online by local principal investigators, with an allocation ratio of 1:1. Treatment with iOLA included an alveolar recruitment manoeuvre to 40 cm H2O of end-inspiratory pressure followed by individualised positive end-expiratory pressure (PEEP) titrated to best respiratory system compliance, and individualised postoperative respiratory support with high-flow oxygen therapy. Participants allocated to standard lung-protective ventilation received combined intraoperative 4 cm H2O of PEEP and postoperative conventional oxygen therapy. The primary outcome was a composite of severe postoperative pulmonary complications within the first 7 postoperative days, including atelectasis requiring bronchoscopy, severe respiratory failure, contralateral pneumothorax, early extubation failure (rescue with continuous positive airway pressure, non-invasive ventilation, invasive mechanical ventilation, or reintubation), acute respiratory distress syndrome, pulmonary infection, bronchopleural fistula, and pleural empyema. Due to trial setting, data obtained in the operating and postoperative rooms for routine monitoring were not blinded. At 24 h, data were acquired by an investigator blinded to group allocation. All analyses were performed on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov, NCT03182062, and is complete.

FINDINGS

Between Sept 11, 2018, and June 14, 2022, we enrolled 1380 patients, of whom 1308 eligible patients (670 [434 male, 233 female, and three with missing data] assigned to iOLA and 638 [395 male, 237 female, and six with missing data] to standard lung-protective ventilation) were included in the final analysis. The proportion of patients with the composite outcome of severe postoperative pulmonary complications within the first 7 postoperative days was lower in the iOLA group compared with the standard lung-protective ventilation group (40 [6%] vs 97 [15%], relative risk 0·39 [95% CI 0·28 to 0·56]), with an absolute risk difference of -9·23 (95% CI -12·55 to -5·92). Recruitment manoeuvre-related adverse events were reported in five patients.

INTERPRETATION

Among patients subjected to lung resection under one-lung ventilation, iOLA was associated with a reduced risk of severe postoperative pulmonary complications when compared with conventional lung-protective ventilation.

FUNDING

Instituto de Salud Carlos III and the European Regional Development Funds.

Intraoperative effects of an alveolar recruitment manoeuvre in patients undergoing laparoscopic colon surgery

INTRODUCTION

Pulmonary atelectasis is common in patients undergoing laparoscopic abdominal surgery under general anaesthesia, which increases the risk of perioperative respiratory complications. Alveolar recruitment manoeuvres (ARM) are used to open up the lung parenchyma with atelectasis, although the duration of their benefit has not been clearly established. The aim of this study was to determine the effectiveness of an ARM in laparoscopic colon surgery, the duration of response over time, and its haemodynamic impact.

METHODS

Twenty-five patients undergoing laparoscopic colon surgery were included. After anaesthetic induction and initiation of surgery with pneumoperitoneum, an ARM was performed, and then optimal PEEP determined. Respiratory mechanics and gas exchange variables, and haemodynamic parameters, were analysed before the manoeuvre and periodically over the following 90 min.

RESULTS

Three patients were excluded for surgical reasons. The alveolar arterial oxygen gradient went from 94.3 (62.3-117.8) mmHg before to 60.7 (29.6-91.0) mmHg after the manoeuvre (P < .05). This difference was maintained during the 90 min of the study. Dynamic compliance of the respiratory system went from 31.3 ml/cmH2O (26.1-39.2) before the manoeuvre to 46.1 ml/cmH2O (37.5-53.5) after the manoeuvre (P < .05). This difference was maintained for 60 min. No significant changes were identified in any of the haemodynamic variables studied.

CONCLUSION

In patients undergoing laparoscopic colon surgery, performing an intraoperative ARM improves the mechanics of the respiratory system and oxygenation, without associated haemodynamic compromise. The benefit of these manoeuvres lasts for at least one hour.

Improving Neuromuscular Monitoring Through Education-Based Interventions and Studying Its Association With Adverse Postoperative Outcomes: A Retrospective Observational Study

BACKGROUND

We assessed the association between education-based interventions, the frequency of train-of-four (TOF) monitoring, and postoperative outcomes.

METHODS

We studied adults undergoing noncardiac surgery from February 1, 2020 through October 31, 2021. Our education-based interventions consisted of 3 phases. An interrupted time-series analysis, adjusting for patient- and procedure-related characteristics and secular trends over time, was used to assess the associations between education-based interventions and the frequency of TOF monitoring, postoperative pulmonary complications (PPCs), 90-day mortality, and sugammadex dosage. For each outcome and intervention phase, we tested whether the intervention at that phase was associated with an immediate change in the outcome or its trend (weekly rate of change) over time. In a sensitivity analysis, the association between education-based interventions and postoperative outcomes was adjusted for TOF monitoring.

RESULTS

Of 19,422 cases, 11,636 (59.9%) had documented TOF monitoring. Monitoring frequency increased from 44.2% in the first week of preintervention stage to 83.4% in the final week of the postintervention phase. During the preintervention phase, the odds of TOF monitoring trended upward by 0.5% per week (odds ratio [OR], 1.005; 95% confidence interval [CI], 1.002-1.007). Phase 1 saw an immediate 54% increase (OR, 1.54; 95% CI, 1.33-1.79) in the odds, and the trend OR increased by 3% (OR, 1.03; 95% CI, 1.01-1.05) to 1.035, or 3.5% per week (joint Wald test, P < .001). Phase 2 was associated with a further immediate 29% increase (OR, 1.29; 95% CI, 1.02-1.64) but no significant association with trend (OR, 0.96; 95% CI, 0.93-1.01) of TOF monitoring (joint test, P = .04). Phase 3 and postintervention phase were not significantly associated with the frequency of TOF monitoring (joint test, P = .16 and P = .61). The study phases were not significantly associated with PPCs or sugammadex administration. The trend OR for 90-day mortality was larger by 24% (OR, 1.24; 95% CI, 1.06-1.45; joint test, P = .03) in phase 2 versus phase 1, from a weekly decrease of 8% to a weekly increase of 14%. However, this trend reversed again at the transition from phase 3 to the postintervention phase (OR, 0.82; 95% CI, 0.68-0.99; joint test, P = .05), from a 14% weekly increase to a 6.2% weekly decrease in the odds of 90-day mortality. In sensitivity analyses, adjusting for TOF monitoring, we found similar associations between study initiatives and postoperative outcomes. TOF monitoring was associated with lower odds of PPCs (OR, 0.69; 95% CI, 0.55-0.86) and 90-day mortality (OR, 0.79; 95% CI, 0.63-0.98), but not sugammadex dosing (mean difference, -0.02; 95% CI, -0.04 to 0.01).

CONCLUSIONS

Our education-based interventions were associated with both TOF utilization and 90-day mortality but were not associated with either the odds of PPCs or sugammadex dosing. TOF monitoring was associated with reduced odds of PPCs and 90-day mortality.

Respiratory effects of pressure support ventilation in spontaneously breathing patients under anaesthesia: Randomised controlled trial

BACKGROUND

Lung volume loss is a major risk factor for postoperative respiratory complications after general anaesthesia and mechanical ventilation. We hypothesise that spontaneous breathing without pressure support may enhance the risk for atelectasis development. Therefore, we aimed at characterising whether pressure support prevents changes in lung function in patients breathing spontaneously through laryngeal mask airway.

METHODS

In this randomised controlled trial, adult female patients scheduled for elective gynaecological surgery in lithotomy position were randomly assigned to the continuous spontaneous breathing group (CSB, n = 20) or to the pressure support ventilation group (PSV, n = 20) in a tertiary university hospital. Lung function measurements were carried out before anaesthesia and 1 h postoperatively by a researcher blinded to the group allocation. Lung clearance index calculated from end-expiratory lung volume turnovers as primary outcome variable was assessed by the multiple-breath nitrogen washout technique (MBW). Respiratory mechanics were measured by forced oscillations to assess parameters reflecting the small airway function and respiratory tissue stiffness.

RESULTS

MBW was successfully completed in 18 patients in both CSB and PSV groups. The decrease in end-expiratory lung volume was more pronounced in the CSB than that in the PSV group (16.6 ± 6.6 [95% CI] % vs. 7.6 ± 11.1%, p = .0259), with no significant difference in the relative changes of the lung clearance index (-0.035 ± 7.1% vs. -0.18 ± 6.6%, p = .963). The postoperative changes in small airway function and respiratory tissue stiffness were significantly lower in the PSV than in the CSB group (p < .05 for both).

CONCLUSIONS

These results suggest that pressure support ventilation protects against postoperative lung-volume loss without affecting ventilation inhomogeneity in spontaneously breathing patients with increased risk for atelectasis development.

TRIAL REGISTRATION

NCT02986269.

Incidence and risk factors of postoperative pulmonary complications after oral cancer surgery with free flap reconstruction: A single center study

BACKGROUND

Postoperative pulmonary complications (PPCs) increase the risk of morbidity and mortality in patients who underwent oral cancer surgery with free flap reconstruction. The association between PPC and preoperative risk factors has been investigated; however, reports on intraoperative factors are limited. Therefore, we investigated PPC incidence and its associated preoperative and intraoperative risk factors in these patients.

METHODS

We retrospectively analyzed medical records of patients who underwent free flap reconstruction between 2009 and 2019. PPC was defined as presence of atelectasis, pneumonia, and respiratory failure based on radiological confirmation and clinical symptoms during hospitalization. Mortality, hospital stay, preoperative factors (including age and tumor stages), American Society of Anesthesiologists (ASA) classification, and intraoperative factors (including intraoperative fluids and medications) were recorded.

RESULTS

PPC incidence among the 993 patients included in this study was 25.8% (256 patients). Six patients with PPCs died; death was not observed among patients without PPCs (p < 0.001). Patients with PPCs had longer hospitalization than those without PPCs (30.3 vs 23.3 days; p < 0.001). Tumor stage (stage I: reference; stage II [OR]: 3.3, p = 0.019; stage III: 4.4, p = 0.002; stage IV: 4.8, p = 0.002), age (OR: 1.0; p < 0.001), and ASA grade >2 (OR: 1.4; p = 0.020) were independent risk factors of PPC; using labetalol was a borderline significant factor (OR: 1.4; p = 0.050).

CONCLUSION

The PPC incidence was 25.8% in patients undergoing oral cancer surgery with free flap reconstruction. Tumor stage, age, and ASA >2 were risk factors of developing PPC.

Adherence to lung protective mechanical ventilation in patients admitted to a surgical intensive care unit and the associated increased mortality

Background

The adherence rate to the lung protective ventilation (LPV) strategy, which is generally accepted as a standard practice in mechanically ventilated patients, reported in the literature is approximately 40%. This study aimed to determine the adherence rate to the LPV strategy, factors associated with this adherence, and related clinical outcomes in mechanically ventilated patients admitted to the surgical intensive care unit (SICU).

Methods

This prospective observational study was conducted in the SICU of a tertiary university-based hospital between April 2018 and February 2019. Three hundred and six adult patients admitted to the SICU who required mechanical ventilation support for more than 12 h were included. Ventilator parameters at the initiation of mechanical ventilation support in the SICU were recorded. The LPV strategy was defined as ventilation with a tidal volume of equal or less than 8 ml/kg of predicted body weight plus positive end-expiratory pressure of at least 5 cm H2O. Demographic and clinical data were recorded and analyzed.

Results

There were 306 patients included in this study. The adherence rate to the LPV strategy was 36.9%. Height was the only factor associated with adherence to the LPV strategy (odds ratio for each cm, 1.10; 95% confidence interval (CI), 1.06-1.15). Cox regression analysis showed that the LPV strategy was associated with increased 90-day mortality (hazard ratio, 1.73; 95% CI, 1.02-2.94).

Conclusion

The adherence rate to the LPV strategy among patients admitted to the SICU was modest. Further studies are warranted to explore whether the application of the LPV strategy is simply a marker of disease severity or a causative factor for increased mortality.

The effects of prone position ventilation on patients with acute respiratory distress syndrome after cardiac surgery

BACKGROUND

This study aimed to investigate the effects of prone position ventilation treatment on patients with acute respiratory distress syndrome (ARDS) after cardiac surgery.

METHODS

Clinical data were collected from 93 hospitalized patients with acute respiratory distress syndrome (ARDS) in the intensive care unit (ICU) of cardiology from February 2021 to February 2023. Patients were divided into supine position group (n = 45) and prone position group (n = 48). The difference in 28-days survival rates, blood gas indicators, respiratory mechanics indicators, and adverse events before and after treatment was analyzed.

RESULTS

We found that within 28 days of admission, 8.33% of ARDS patients in prone position group and 11.11% in supine position group died of all causes (p > .05). After treatment, the levels of arterial PaO2 (103.25 ± 9.44 in prone position group and 91.62 ± 9.18 in supine position group), PaCO2 (30.26 ± 5.54 and 36.56 ± 6.37), blood LAC (1.35 ± 0.37 and 1.68 ± 0.42), oxygenation (232.23 ± 28.56 and 205.13 ± 31.34) and diffusion index (453.48 ± 63.30 and 395.18 ± 58.54) in both groups were improved (p < .001). Moreover, the increase in prone position group was more remarkable. After treatment, the respiratory mechanics indexes of the lung compliance as well as respiratory resistance were improved (p < .05). Moreover, the increase in supine position group was more remarkable (p < .05). The incidence of atelectasis in prone position group was lower than that in supine position group (p < .05). Additionally, the alteration in other adverse events showed no significant difference between the two groups (p > .05).

CONCLUSIONS

Taken together, prone position ventilation in patients with ARDS after cardiac surgery improved blood gas indexes, hypoxemia, and respiratory mechanics indexes, as well as reduced the incidence of atelectasis.