Routine lung ultrasound to detect postoperative pulmonary complications following major abdominal surgery: a prospective observational feasibility study

Can the lung ultrasound score predict pulmonary complications after non-thoracic surgery in patients with blunt thoracic trauma: A single-center observational study

STUDY OBJECTIVE

Patients with blunt thoracic trauma have a high risk of developing postoperative pulmonary complications (PPCs). In this study, we aimed to identify the risk factors for PPCs after non-thoracic surgery in patients with blunt thoracic trauma and investigate the efficacy of perioperative lung ultrasound scores in predicting PPC occurrence.

DESIGN

Prospective observational study.

SETTING

A Chinese tertiary orthopedic hospital.

PARTICIPANTS

This observational study included 369 patients with blunt thoracic trauma who underwent surgery for pelvic and upper or lower extremity fractures.

INTERVENTIONS

Lung ultrasonography was performed pre- and postoperatively.

MEASUREMENTS

Patients were followed up for 1 week to assess PPCs and assigned to the PPC or non-PPC groups. We identified risk factors for PPCs using univariate and multivariate logistic regression analyses. The predictive value of these risk factors was evaluated using receiver operating characteristic (ROC) curves.

MAIN RESULTS

PPCs incidence was 36.58 %. The two groups differed significantly in Injury Severity Scores, American Society of Anesthesiologists (ASA) classification, chronic obstructive pulmonary disease, hydrothorax, preoperative hypoxemia, lung ultrasound score, preoperative hemoglobin level, intraoperative infusion volume, and Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) scores (P < 0.05). Independent risk factors for PPCs included ASA classification III, higher postoperative lung ultrasound scores, preoperative anemia, higher intraoperative infusion volume, and higher ARISCAT scores. ROC curve analysis revealed that postoperative lung ultrasound score (area under the curve [AUC]: 0.810, cutoff: 10), preoperative hemoglobin level (AUC: 0.627, cutoff: 97), intraoperative infusion volume (AUC: 0.701, cutoff: 886.51 mL/h) and ARISCAT score (AUC: 0.718, cutoff: 33) predicted postoperative outcomes effectively.

CONCLUSIONS

Postoperative lung ultrasound scores reliably predicted pulmonary complications after non-thoracic surgery in patients with blunt thoracic trauma. ASA classification III, preoperative anemia, excessive intraoperative fluid infusion, higher ARISCAT, and postoperative lung ultrasound scores were significant risk factors associated with PPCs.

TRIAL REGISTRATION

Clinical Trial Number: 1900023408. Registered on May 26, 2019.

Lung Ultrasound Score on Postoperative Day 1 Is Predictive of the Occurrence of Pulmonary Complications after Major Abdominal Surgery: A Multicenter Prospective Observational Study

BACKGROUND

Postoperative pulmonary complications after major abdominal surgery are frequent and carry high morbidity and mortality. Early identification of patients at risk of pulmonary complications by lung ultrasound may allow the implementation of preemptive strategies. The authors hypothesized that lung ultrasound score would be associated with pulmonary postoperative complications. The main objective of the study was to evaluate the performance of lung ultrasound score on postoperative day 1 in predicting pulmonary complications after major abdominal surgery. Secondary objectives included the evaluation of other related measures for their potential prediction accuracy.

METHODS

A total of 149 patients scheduled for major abdominal surgery were enrolled in a bicenter observational study. Lung ultrasound score was performed before the surgery and on days 1, 4, and 7 after surgery. Pulmonary complications occurring before postoperative day 10 were recorded.

RESULTS

Lung ultrasound score on postoperative day 1 was higher in patients developing pulmonary complications before day 10 (median, 13; interquartile range, 8.25 to 18; vs. median, 10; interquartile range, 6.5 to 12; Mann-Whitney P = 0.002). The area under the curve for predicting postoperative pulmonary complications before day 10 was 0.65 (95% CI, 0.55 to 0.75; P = 0.003). Lung ultrasound score greater than 12 had a sensitivity of 0.54 (95% CI, 0.40 to 0.67), specificity of 0.77 (95% CI, 0.67 to 0.85), and negative predictive value of 0.74 (95% CI, 0.65 to 0.83). Lung ultrasound score greater than 17 had sensitivity of 0.33 (95% CI, 0.21 to 0.47), specificity of 0.95 (95% CI, 0.88 to 0.98), and positive predictive value of 0.78 (95% CI, 0.56 to 0.93). Anterolateral lung ultrasound score and composite scores using lung ultrasound score and other patient characteristics showed similar predictive accuracies.

CONCLUSIONS

An elevated lung ultrasound score on postoperative day 1 is associated with the occurrence of pulmonary complications within the first 10 days after major abdominal surgery.

EDITOR’S PERSPECTIVE

A preoperative ultrasound-based protocol for optimisation of fluid therapy to prevent early intraoperative hypotension: a randomised controlled study

BACKGROUND

Intraoperative hypotension is a risk factor for postoperative complications. Preoperative dehydration is a major contributor, although it is difficult to estimate its severity. Point-of-care ultrasound offers several potential methods, including measurements of the inferior vena cava. The addition of lung ultrasound may offer a safety limit. We aimed to evaluate whether the implication of an ultrasound-based preoperative fluid therapy protocol can decrease the incidence of early intraoperative hypotension.

METHODS

Randomised controlled study in a tertiary university department involves elective surgical patients of ASA 2-3 class, scheduled for elective major abdominal surgery under general anaesthesia with intubation. We randomised 40-40 patients; 38-38 were available for analysis. Conventional fluid therapy was ordered on routine preoperative visits. Ultrasound-based protocol evaluated the collapsibility index of inferior vena cava and lung ultrasound profiles. Scans were performed twice: 2 h and 30 min before surgery. A high collapsibility index (≥ 40%) indicated a standardised fluid bolus, while the anterior B-profile of the lung ultrasound contraindicated further fluid. The primary outcome was the incidence of postinduction and early intraoperative (0-10 min) hypotension (MAP < 65 mmHg and/or ≥ 30% of decrease from baseline). Secondary endpoints were postoperative lactate level, urine output and lung ultrasound score at 24 h.

RESULTS

The absolute criterion of postinduction hypotension was fulfilled in 12 patients in the conventional group (31.6%) and 3 in the ultrasound-based group (7.9%) (p = 0.0246). Based on composite criteria of absolute and/or relative hypotension, we observed 17 (44.7%) and 7 (18.4%) cases, respectively (p = 0.0136). The incidence of early intraoperative hypotension was also lower: HR for absolute hypotension was 2.10 (95% CI 1.00-4.42) in the conventional group (p = 0.0387). Secondary outcome measures were similar in the study groups.

CONCLUSION

We implemented a safe and effective point-of-care ultrasound-based preoperative fluid replacement protocol into perioperative care.

TRIAL REGISTRATION

The study was registered to ClinicalTrials.gov on 10/12/2021, registration number: NCT05171608 (registered prospectively on 10/12/2021).

Point-of-Care Ultrasound: A Moving Picture Is Worth a Thousand Tests

The effective utilization of point-of-care ultrasound may decrease the utilization of conventional diagnostic modalities. This review describes the various pathologies that can be effectively and rapidly identified with point-of-care cardiac, lung, abdominal, vascular airway, and ocular ultrasonography.

Comparison of the effects of neostigmine and sugammadex on postoperative residual curarization and postoperative pulmonary complications by means of diaphragm and lung ultrasonography: a study protocol for prospective double-blind randomized controlled trial

Background

Postoperative residual curarization (PORC) may be a potential risk factor of postoperative pulmonary complications (PPCs), and both of them will lead to adverse consequences on surgical patient recovery. The train-of-four ratio (TOFr) which is detected by acceleromyography of the adductor pollicis is thought as the gold standard for the measurement of PORC. However, diaphragm function recovery may differ from that of the peripheral muscles. Recent studies suggested that diaphragm ultrasonography may be useful to reveal the diaphragm function recovery, and similarly, lung ultrasound was reported for the assessment of PPCs in recent years as well. Sugammadex reversal of neuromuscular blockade is rapid and complete, and there appear to be fewer postoperative complications than with neostigmine. This study aims to compare the effects of neostigmine and sugammadex, on PORC and PPCs employing diaphragm and lung ultrasonography, respectively.

Methods/design

In this prospective, double-blind, randomized controlled trial, patients of the American Society of Anesthesiologists Physical Status I–III, aged over 60, will be enrolled. They will be scheduled to undergo arthroplasty under general anesthesia. All patients will be allocated randomly into two groups, group NEO (neostigmine) and group SUG (sugammadex), using these two drugs for reversing rocuronium. The primary outcome of the study is the incidence of PPCs in the NEO and SUG groups. The secondary outcomes are the evaluation of diaphragm ultrasonography and lung ultrasound, performed by an independent sonographer before anesthesia, and at 10 min and 30 min after extubation in the post-anesthesia care unit, respectively.

Discussion

Elimination of PORC is a priority at the emergence of anesthesia, and it may be associated with reducing postoperative complications like PPCs. Sugammadex was reported to be superior to reverse neuromuscular blockade than neostigmine. Theoretically, complete recovery of neuromuscular function should be indicated by TOFr > 0.9. However, the diaphragm function recovery may not be the same matter, which probably harms pulmonary function. The hypothesis will be proposed that sugammadex is more beneficial than neostigmine to reduce the incidence of PPCs and strongly favorable for the recovery of diaphragm function in our study setting.

Trial registration

ClinicalTrials.gov NCT05040490. Registered on 3 September 2021

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06328-3.

Effects of preoperative physiotherapy on signs and symptoms of pulmonary collapse and infection after major abdominal surgery: secondary analysis of the LIPPSMAck-POP multicentre randomised controlled trial

Background

Preoperative education and breathing exercise training by a physiotherapist minimises pulmonary complications after abdominal surgery. Effects on specific clinical outcomes such as antibiotic prescriptions, chest imaging, sputum cultures, oxygen requirements, and diagnostic coding are unknown.

Methods

This post hoc analysis of prospectively collected data within a double-blinded, multicentre, randomised controlled trial involving 432 participants having major abdominal surgery explored effects of preoperative education and breathing exercise training with a physiotherapist on postoperative antibiotic prescriptions, hypoxemia, sputum cultures, chest imaging, auscultation, leukocytosis, pyrexia, oxygen therapy, and diagnostic coding, compared to a control group who received a booklet alone. All participants received standardised postoperative early ambulation. Outcomes were assessed daily for 14 postoperative days. Analyses were intention-to-treat using adjusted generalised multivariate linear regression.

Results

Preoperative physiotherapy was associated with fewer antibiotic prescriptions specific for a respiratory infection (RR 0.52; 95% CI 0.31 to 0.85, p = 0.01), less purulent sputum on the third and fourth postoperative days (RR 0.50; 95% CI 0.34 to 0.73, p = 0.01), fewer positive sputum cultures from the third to fifth postoperative day (RR 0.17; 95% CI 0.04 to 0.77, p = 0.01), and less oxygen therapy requirements (RR 0.49; 95% CI 0.31 to 0.78, p = 0.002). Treatment effects were specific to respiratory clinical coding domains.

Conclusions

Preoperative physiotherapy prevents postoperative pulmonary complications and is associated with the minimisation of signs and symptoms of pulmonary collapse/consolidation and airway infection and specifically results in reduced oxygen therapy requirements and antibiotic prescriptions.

Trial registration

ANZCTR 12613000664741; 19/06/2013.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13741-021-00206-3.

Perioperative high inspired oxygen fraction induces atelectasis in patients undergoing abdominal surgery: A randomized controlled trial

STUDY OBJECTIVE

We evaluated the feasibility of use and effects on postoperative atelectasis and complications of lower inspired oxygen fraction (FIO₂) compared to conventional oxygen therapy.

DESIGN

Single center, randomized clinical trial.

SETTING

University hospital, operating room and postoperative recovery area.

PATIENTS

One hundred ninety patients aged ≥50 with an American Society of Anesthesiologists physical status of I-III who underwent abdominal surgery with general anesthesia.

INTERVENTIONS

Participants were randomly assigned to either the low FIO₂ group (intraoperative: FIO₂ 0.35, during induction and recovery: FIO₂ 0.7) or the conventional FIO₂ group (intraoperative: FIO₂ 0.6, during induction and recovery: FIO₂ 1.0).

MEASUREMENTS

The primary outcome was postoperative atelectasis measured with lung ultrasonography at postoperative 30 min in the post-anesthesia care unit (consolidation score: each region 0-3, 12 region, total score range of 0 to 36, a lower score indicating better aeration).

MAIN RESULTS

Seven patients in the low FIO₂ group were omitted from the study due to changing FIO₂ during intervention (7/95 (8.4%) vs. 2/95 (2.1%), p = 0.088; low FIO₂ group vs. conventional FIO₂ group). Overall, atelectasis was detected in 29.7% (51/172) of patients 30 min after surgery by lung ultrasound and 40.1% (69/172) of patients after 2 days after surgery by chest X-ray. The scores of lung ultrasonography and the incidence of significant atelectasis (consolidation score ≥ 2 at any region) were lower in the low FIO₂ group than in the conventional FIO₂ group (median [IQR]: 3 [1,6] vs. 7 [3,9], p < 0.001 and 17/85 (20%) vs. 34/87 (39%), RR: 0.512 [95% CI: 0.311-0.843], p = 0.006, respectively). The incidence of surgical site infection and length of hospitalization were not significantly different between the two groups.

CONCLUSIONS

Based on our findings, decreased inspired oxygen fraction during anesthesia and recovery did not cause hypoxic events, but instead reduced immediate postoperative atelectasis. The use of intraoperative conventional higher inspired oxygen did not afford any clinical advantages for postoperative recovery in abdominal surgery.

The diagnostic accuracy of lung auscultation in adult patients with acute pulmonary pathologies: a meta-analysis

The stethoscope is used as first line diagnostic tool in assessment of patients with pulmonary symptoms. However, there is much debate about the diagnostic accuracy of this instrument. This meta-analysis aims to evaluate the diagnostic accuracy of lung auscultation for the most common respiratory pathologies. Studies concerning adult patients with respiratory symptoms are included. Main outcomes are pooled estimates of sensitivity and specificity with 95% confidence intervals, likelihood ratios (LRs), area under the curve (AUC) of lung auscultation for different pulmonary pathologies and breath sounds. A meta-regression analysis is performed to reduce observed heterogeneity. For 34 studies the overall pooled sensitivity for lung auscultation is 37% and specificity 89%. LRs and AUC of auscultation for congestive heart failure, pneumonia and obstructive lung diseases are low, LR− and specificity are acceptable. Abnormal breath sounds are highly specific for (hemato)pneumothorax in patients with trauma. Results are limited by significant heterogeneity. Lung auscultation has a low sensitivity in different clinical settings and patient populations, thereby hampering its clinical utility. When better diagnostic modalities are available, they should replace lung auscultation. Only in resource limited settings, with a high prevalence of disease and in experienced hands, lung auscultation has still a role.