Optimization of cardiopulmonary bypass prime fluid to preserve microcirculatory perfusion during on-pump coronary artery bypass graft surgery: PRIME study protocol for a double-blind randomized trial

BACKGROUND

Acute microcirculatory perfusion disturbances and organ edema are important factors leading to organ dysfunction during cardiac surgery with cardiopulmonary bypass (CPB). Priming of the CPB system with crystalloid or colloid fluids, which inevitably leads to hemodilution, could contribute to this effect. However, there is yet no optimal evidence-based strategy for this type of priming. Hence, we will investigate different priming strategies to reduce hemodilution and preserve microcirculatory perfusion.

METHODS

The PRIME study is a single-center double-blind randomized trial. Patients undergoing elective coronary artery bypass graft surgery with CPB will be randomized into three groups of prime fluid strategy: (1) gelofusine with crystalloid, (2) albumin with crystalloid, or (3) crystalloid and retrograde autologous priming. We aim to include 30 patients, 10 patients in each arm. The primary outcome is the change in microcirculatory perfusion. Secondary outcomes include colloid oncotic pressure; albumin; hematocrit; electrolytes; fluid balance and requirements; transfusion rates; and endothelial-, glycocalyx-, inflammatory- and renal injury markers. Sublingual microcirculatory perfusion will be measured using non-invasive sidestream dark field video microscopy. Microcirculatory and blood measurements will be performed at five consecutive time points during surgery up to 24 h after admission to the intensive care unit.

DISCUSSION

PRIME is the first study to assess the effect of different prime fluid strategies on microcirculatory perfusion in cardiac surgery with CPB. If the results suggest that a specific crystalloid or colloid prime fluid strategy better preserves microcirculatory perfusion during on-pump cardiac surgery, the current study may help to find the optimal pump priming in cardiac surgery.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05647057. Registered on 04/25/2023.

CLINICALTRIALS

gov PRS: Record Summary NCT05647057, all items can be found in the protocol.

Development and Validation of Scores to Predict Prolonged Mechanical Ventilation after Cardiac Surgery

OBJECTIVES

To optimize the early prediction of prolonged postoperative mechanical ventilation after cardiac surgery (>24 hours postoperatively).

DESIGN

The authors performed a retrospective analysis.

SETTING

The Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) database was utilized.

PARTICIPANTS

All patients included in the ANZSCTS database between January 2015 and December 2018 were analyzed.

INTERVENTIONS

No interventions were performed in this observational study.

MEASUREMENTS AND MAIN RESULTS

A previously developed model was modified to allow retrospective risk calculation and model assessment (Modified Hessels score). The database was split into development and validation sets. A new risk model was developed using forward and backward stepwise elimination (ANZ-PreVent score). The authors assessed 48,382 patients, of whom 5004 (10.3%) were ventilated mechanically for >24 hours post-operatively. The Modified Hessels score demonstrated good performance in this database, with a c-index of 0.78 (95% CI 0.77-0.78) and a Brier score of 0.08. The newly developed ANZ-PreVent score demonstrated better performance (validation cohort, n = 12,229), with a c-index of 0.84 (95% CI 0.83-0.85) (p < 0.0001) and a Brier score of 0.07. Both scores performed better than the severity of illness scores commonly used to predict outcomes in intensive care.

CONCLUSIONS

The authors validated a modified version of an existing prediction score and developed the ANZ-PreVent score, with improved performance for identifying patients at risk of ventilation for >24 hours. The improved score can be used to identify high-risk patients for targeted interventions in future randomized controlled trials.

A Least Absolute Shrinkage and Selection Operator-Derived Predictive Model for Postoperative Respiratory Failure in a Heterogeneous Adult Elective Surgery Patient Population

BACKGROUND

Postoperative respiratory failure (PRF) is associated with increased hospital charges and worse patient outcomes. Reliable prediction models can help to guide postoperative planning to optimize care, to guide resource allocation, and to foster shared decision-making with patients.

RESEARCH QUESTION

Can a predictive model be developed to accurately identify patients at high risk of PRF?

STUDY DESIGN AND METHODS

In this single-site proof-of-concept study, we used structured query language to extract, transform, and load electronic health record data from 23,999 consecutive adult patients admitted for elective surgery (2014-2021). Our primary outcome was PRF, defined as mechanical ventilation after surgery of > 48 h. Predictors of interest included demographics, comorbidities, and intraoperative factors. We used logistic regression to build a predictive model and the least absolute shrinkage and selection operator procedure to select variables and to estimate model coefficients. We evaluated model performance using optimism-corrected area under the receiver operating curve and area under the precision-recall curve and calculated sensitivity, specificity, positive and negative predictive values, and Brier scores.

RESULTS

Two hundred twenty-five patients (0.94%) demonstrated PRF. The 18-variable predictive model included: operations on the cardiovascular, nervous, digestive, urinary, or musculoskeletal system; surgical specialty orthopedic (nonspine); Medicare or Medicaid (as the primary payer); race unknown; American Society of Anesthesiologists class ≥ III; BMI of 30 to 34.9 kg/m2; anesthesia duration (per hour); net fluid at end of the operation (per liter); median intraoperative FIO2, end title CO2, heart rate, and tidal volume; and intraoperative vasopressor medications. The optimism-corrected area under the receiver operating curve was 0.835 (95% CI,0.808-0.862) and the area under the precision-recall curve was 0.156 (95% CI, 0.105-0.203).

INTERPRETATION

This single-center proof-of-concept study demonstrated that a structured query language extract, transform, and load process, based on readily available patient and intraoperative variables, can be used to develop a prediction model for PRF. This PRF prediction model is scalable for multicenter research. Clinical applications include decision support to guide postoperative level of care admission and treatment decisions.

Impact of Pulmonary Complications on Outcomes and Resource Use After Elective Cardiac Surgery

OBJECTIVE

To characterize the impact of pulmonary complications (PCs) on mortality, costs, and readmissions after elective cardiac operations in a national cohort and to test for hospital-level variation in PC.

BACKGROUND

PC after cardiac surgery are targets for quality improvement efforts. Contemporary studies evaluating the impact of PC on outcomes are lacking, as is data regarding hospital-level variation in the incidence of PC.

METHODS

Adults undergoing elective coronary artery bypass grafting and/or valve operations were identified in the 2016-2019 Nationwide Readmissions Database. PC was defined as a composite of reintubation, prolonged (>24 hours) ventilation, tracheostomy, or pneumonia. Generalized linear models were fit to evaluate associations between PC and outcomes. Institutional variation in PC was studied using observed-to-expected ratios.

RESULTS

Of 588,480 patients meeting study criteria, 6.7% developed PC. After risk adjustment, PC was associated with increased odds of mortality (14.6, 95% CI, 12.6-14.8), as well as a 7.9-day (95% CI, 7.6-8.2) increase in length of stay and $41,300 (95% CI, 39,600-42,900) in attributable costs. PC was associated with 1.3-fold greater hazard of readmission and greater incident mortality at readmission (6.7% vs 1.9%, P <0.001). Significant hospital-level variation in PC was present, with observed-to-expected ratios ranging from 0.1 to 7.7.

CONCLUSIONS

Pulmonary complications remain common after cardiac surgery and are associated with substantially increased mortality and expenditures. Significant hospital-level variation in PC exists in the United States, suggesting the need for systematic quality improvement efforts to reduce PC and their impact on outcomes.

Nomogram and Risk Calculator for Postoperative Tracheostomy after Heart Valve Surgery

Postoperative tracheostomy (POT) is an important indicator of critical illness, associated with poorer prognoses and increased medical burdens. However, studies on POTs after heart valve surgery (HVS) have not been reported. The objectives of this study were first to identify the risk factors and develop a risk prediction model for POTs after HVS, and second to clarify the relationship between POTs and clinical outcomes. Consecutive adults undergoing HVS from January 2016 to December 2019 in a single cardiovascular center were enrolled, and a POT was performed in 1.8% of the included patients (68/3853). Compared to patients without POTs, the patients with POTs had higher rates of readmission to the ICU and in-hospital mortality, as well as longer ICU and hospital stays. Five factors were identified to be significantly associated with POTs after HVS by our multivariate analysis, including age, diabetes mellitus, pulmonary edema, intraoperative transfusion of red blood cells, and surgical types. A nomogram and a risk calculator were constructed based on the five factors, showing excellent discrimination, calibration, and clinical utility. Three risk intervals were defined as low-, medium-, and high-risk groups according to the nomogram and clinical practice. The findings of this study may be helpful for early risk assessment and perioperative management.

Efficacy of maintaining low-tidal volume mechanical ventilation as compared to resting lung strategy during coronary artery bypass graft cardiopulmonary bypass surgery: A post-hoc analysis of the MECANO trial

STUDY OBJECTIVE

To compare a low-tidal-volume with positive end-expiratory pressure strategy (VENT strategy) to a resting-lung-strategy (i.e., no-ventilation (noV) strategy) during cardiopulmonary bypass for coronary artery bypass graft surgery on the incidence of postoperative pulmonary complications.

DESIGN

Post-hoc analysis of the MECANO trial which was a prospective single-center, blind, randomized, parallel-group controlled trial.

SETTING

Tertiary care cardiac surgery center.

PATIENTS

Patients who underwent isolated on-pump coronary bypass surgery were randomized either to VENT or noV group.

INTERVENTION

During the cardiopulmonary bypass phase of the cardiac surgery procedure, mechanical ventilation in the VENT group consisted of a tidal volume of 3 mL/kg, a respiratory rate of 5 per minute and a positive end-expiratory pressure of 5 cmH₂O. Patients in the noV group received no ventilation during this phase.

MEASUREMENTS

Primary composite outcome combining death, early respiratory failure, ventilation support beyond day 2 and reintubation.

MAIN RESULTS

In this post-hoc analysis, we retained 725 patients who underwent isolated CABG surgery, from the 1501 patients included in the original study. There were 352 in the VENT group and 373 patients in the noV group. Post-hoc comparison yielded no differences in baseline characteristics between these two groups. The primary outcome occurred less frequently in the VENT group than in the noV group, with 44 (12.5%) and 76 (20.4%) respectively (odds-ratio (OR) = 0.56 (0.37-0.84), p = 0.004). There were fewer early respiratory dysfunctions and prolonged respiratory support in the VENT group (respectively, OR = 0.34 (0.12-0.96) p = 0.033 and OR = 0.51 (0.27-0.94) p = 0.029). Complications related to mechanical ventilation were similar in the two groups.

CONCLUSIONS

In this post-hoc analysis, maintaining low-tidal ventilation compared to a resting-lung strategy was associated with fewer pulmonary postoperative complications in patients who underwent isolated CABG procedures.

Outcomes and risk factors for delayed-onset postoperative respiratory failure: a multi-center case-control study by the University of California Critical Care Research Collaborative (UC3RC)

BACKGROUND

Few interventions are known to reduce the incidence of respiratory failure that occurs following elective surgery (postoperative respiratory failure; PRF). We previously reported risk factors associated with PRF that occurs within the first 5 days after elective surgery (early PRF; E-PRF); however, PRF that occurs six or more days after elective surgery (late PRF; L-PRF) likely represents a different entity. We hypothesized that L-PRF would be associated with worse outcomes and different risk factors than E-PRF.

METHODS

This was a retrospective matched case-control study of 59,073 consecutive adult patients admitted for elective non-cardiac and non-pulmonary surgical procedures at one of five University of California academic medical centers between October 2012 and September 2015. We identified patients with L-PRF, confirmed by surgeon and intensivist subject matter expert review, and matched them 1:1 to patients who did not develop PRF (No-PRF) based on hospital, age, and surgical procedure. We then analyzed risk factors and outcomes associated with L-PRF compared to E-PRF and No-PRF.

RESULTS

Among 95 patients with L-PRF, 50.5% were female, 71.6% white, 27.4% Hispanic, and 53.7% Medicare recipients; the median age was 63 years (IQR 56, 70). Compared to 95 matched patients with No-PRF and 319 patients who developed E-PRF, L-PRF was associated with higher morbidity and mortality, longer hospital and intensive care unit length of stay, and increased costs. Compared to No-PRF, factors associated with L-PRF included: preexisiting neurologic disease (OR 4.36, 95% CI 1.81-10.46), anesthesia duration per hour (OR 1.22, 95% CI 1.04-1.44), and maximum intraoperative peak inspiratory pressure per cm H₂0 (OR 1.14, 95% CI 1.06-1.22).

CONCLUSIONS

We identified that pre-existing neurologic disease, longer duration of anesthesia, and greater maximum intraoperative peak inspiratory pressures were associated with respiratory failure that developed six or more days after elective surgery in adult patients (L-PRF). Interventions targeting these factors may be worthy of future evaluation.

Effect of high-flow nasal therapy on patient-centred outcomes in patients at high risk of postoperative pulmonary complications after cardiac surgery: a study protocol for a multicentre adaptive randomised controlled trial

BACKGROUND

High-flow nasal therapy is a non-invasive form of respiratory support that delivers low-level, flow dependent positive airway pressure. The device can be better tolerated by patients than alternatives such as continuous positive airway pressure. The primary objective is to determine if prophylactic high-flow nasal therapy after tracheal extubation can result in an increase in the number of days alive and at home within the first 90 days after surgery, when compared with standard oxygen therapy. The co-primary objective is to estimate the incremental cost-effectiveness and cost-utility of high-flow nasal therapy vs standard oxygen therapy at 90 days, from the view-point of the public sector, the health service and patients.

METHODS

This is an adaptive, multicentre, international parallel-group, randomised controlled trial with embedded cost-effectiveness analysis comparing the use of high-flow nasal therapy with control in patients at high risk of respiratory complications following cardiac surgery. Participants will be randomised before tracheal extubation and allocated either high-flow nasal therapy or standard oxygen therapy for a minimum of 16 h immediately post extubation. Participants will be followed up until 90 days after surgery. The total sample size needed to detect a 2-day increase in DAH90 with 90% power with an intention to treat analysis is 850 patients. The adaptive design includes an interim sample size re-estimation which will provide protection against deviations from the original sample size assumptions made from the single-centre pilot study and will allow for a maximum sample size increase to 1152 patients.

DISCUSSION

Evidence to support routine use of high-flow nasal therapy will inform the development of effective enhanced recovery care bundles. Reducing complications should reduce length of stay and re-admission to hospital and provide an important focus for cost reduction. However; high-quality studies evaluating the clinical and cost effectiveness of high-flow nasal therapy after cardiothoracic surgery are lacking.

TRIAL REGISTRATION

The study has been registered with ISRCTN ( ISRCTN14092678 , 13/05/2020) Clinicaltrials.gov Registration Pending.

Outcomes of cardiac surgery in patients with end-stage renal disease: Insights from the Israel national registries

BACKGROUND

End-stage renal disease (ESRD) has been shown to be associated with increased mortality in patients undergoing cardiac surgery. We aimed to compare the short- and mid-term mortality after cardiac surgery of patients with dialysis-dependent ESRD (DD-ESRD) to patients with normal renal function (NRF), using national registries: the ESRD registry, the adult cardiac surgery registry (ACSR), and the National Mortality Registry.

METHODS

The study population comprised 8207 adult patients who underwent either isolated coronary artery bypass grafting (CABG), isolated aortic valve replacement (AVR), isolated mitral valve replacement (MVR), or CABG + valve-related procedure, between January 2017 and April 2019. Data were retrospectively extracted and reported to the ACSR by the department of medical records of each medical center.

RESULTS

One hundred and four DD-ESRD patients (mean age 63.2 ± 8.8 years, 83.7% males) were compared with 8103 NRF patients (mean age 64.9 ± 9.8 years, 77.6% males). Median follow-up for the total cohort was of 32.0 months (IQR; 25.0, 40.0). In DD-ESRD compared to NRF patients, 30-day mortality was higher (14.4% vs. 2.3%, respectively, p = 0.0001) and 4-year survival was significantly lower (44% ± 0.06 vs. 91% ± 0.04, respectively, p = 0.0001). Fifty-three percent of DD-ESRD 30-day mortality was caused by sepsis. Risk factors associated with reduced midterm survival included: DD-ESRD patients (HR = 4.7, 95% CI; 1.2-18.2), MVR procedure (HR = 1.5, 95% CI; 1.04-2.1) and combined CABG + valve-related procedure (HR = 1.6, 95% CI; 1.2-2.04).

CONCLUSIONS

Preoperative DD-ESRD was associated with a significant increase in 30-day and mid-term mortality after cardiac surgery. The highest mortality rate was observed in valvular and combined procedures.

A Predictive Scoring Model for Postoperative Tracheostomy in Patients Who Underwent Cardiac Surgery

Background

A subset of patients require a tracheostomy as respiratory support in a severe state after cardiac surgery. There are limited data to assess the predictors for requiring postoperative tracheostomy (POT) in cardiac surgical patients.

Methods

The records of adult patients who underwent cardiac surgery from 2016 to 2019 at our institution were reviewed. Univariable analysis was used to assess the possible risk factors for POT. Then multivariable logistic regression analysis was performed to identify independent predictors. A predictive scoring model was established with predictor assigned scores derived from each regression coefficient divided by the smallest one. The area under the receiver operating characteristic curve and the Hosmer-Lemeshow goodness-of-fit test were used to evaluate the discrimination and calibration of the risk score, respectively.

Results

A total of 5,323 cardiac surgical patients were included, with 128 (2.4%) patients treated with tracheostomy after cardiac surgery. Patients with POT had a higher frequency of readmission to the intensive care unit (ICU), longer stay, and higher mortality (p &lt; 0.001). Mixed valve surgery and coronary artery bypass grafting (CABG), aortic surgery, renal insufficiency, diabetes mellitus, chronic obstructive pulmonary disease (COPD), pulmonary edema, age &gt;60 years, and emergent surgery were independent predictors. A 9-point risk score was generated based on the multivariable model, showing good discrimination [the concordance index (c-index): 0.837] and was well-calibrated.

Conclusions

We established and verified a predictive scoring model for POT in patients who underwent cardiac surgery. The scoring model was conducive to risk stratification and may provide meaningful information for clinical decision-making.

The death risk factors of patients undergoing re-exploration for bleeding or tamponade after isolated off-pump coronary artery bypass grafting: a case-control study

Background

The purpose of the study is to identify off-pump patients who are at higher risk of mortality after re-exploration for bleeding or tamponade.

Methods

We analyzed the data of 3256 consecutive patients undergoing isolated off-pump coronary artery bypass grafting (OPCABG) in our heart center from 2013 through 2020. Fifty-eight patients underwent re-exploration after OPCABG. The 58 patients were divided into death group and survival group according to their discharge status. Propensity score matching (PSM) was performed to analysis the risk factors of death. 15 pairs of cases of two groups were matched well.

Results

The mortality rate of patients underwent re-exploration after OPCABG for bleeding or tamponade was 27.59% (16/58). In the raw data, we found the patients in death group had higher body mass index (BMI) (P = 0.030), higher cardiac troponin T (cTnT) (P = 0.028) and higher incidence of heart failure before OPCABG (P = 0.003). After PSM, the levels of lactic acid before and after re-exploration (P = 0.028 and P < 0.001) were higher in death group. And the levels of creatinine (P = 0.002) and cTnT (P = 0.017) were higher in the death group after re-exploration. The death group had longer reoperation time (P = 0.010). In addition, the perioperative utilization rate of intra-aortic ballon pump (IABP) (P = 0.027), continuous renal replacement therapy (CRRT) (P < 0.001) and platelet transfusion (P = 0.017) were higher than survival group.

Conclusions

The mortality rate of patients undergoing re-exploration for bleeding or tamponade after isolated OPCABG is high. More attention should be paid to patients with above risk factors and appropriate measures should be taken in time.

Predictors and outcomes of postoperative respiratory failure after cardiac surgery

BACKGROUND

Postoperative respiratory failure after cardiac surgery (CS-PRF) is a devastating complication and its incidence and predictors vary depending on how it is defined and the patient population.

AIMS

This study was conducted to determine the incidence, predictors and outcomes of CS-PRF defined as prolonged mechanical ventilation >48 hours and reintubation.

METHODS

This is a retrospective chart review of 1257 patients who underwent cardiac surgery between June 2011 and December 2018. The research questions were addressed through bivariate inferential, descriptive and binary logistic regression.

RESULTS

The overall incidence of CS-PRF was 15.9% and significant regression predictors included diabetes mellitus (OR = 1.77, P = .001), preoperative renal replacement therapy (OR = 2.07, P = .033), need for intraoperative transfusion (OR = 2.35, P = .000), combined coronary bypass/valvular surgery (OR = 2.61, P = .001) and intra-aortic balloon pump (OR = 3.60, P = .000). CS-PRF patients had increased postoperative blood transfusions (69.5% vs 27.9%, P = .000), reoperation for bleeding (9.0 vs 0.4%, P = .000), pleural effusion (13.5% vs 4.1%, P = .000), pneumonia (33.5% vs 1.6%, P = .000), acute kidney injury (70.9% vs 39.9%, P = .000), atrial fibrillation (42.5% vs 26.3%, P = .000), coma/encephalopathy (21.5% vs 3.3%, P = .000) and cerebrovascular accident (6.0% vs 1.3%, P = .000). They also had longer intensive care (262.1 vs 97.4 hours, P = .000) and hospital lengths of stay (17 vs 8 days, P = .000), and increased in-hospital mortality (17.5% vs 0.4%, P = .000). Survivors of CS-PRF were less likely to be discharged home (38.0% vs 84.4%, P = .000).

CONCLUSIONS

Knowledge of predictors for CS-PRF may help identify patients who are at risk for this complication and who may benefit from preventive measures to promote early extubation and to avert reintubation.

The N-terminal lectin-like domain of thrombomodulin reduces acute lung injury without anticoagulant effects in a rat cardiopulmonary bypass model

OBJECTIVES

Systemic inflammation evoked by cardiopulmonary bypass (CPB) leads to acute lung injury (ALI) and respiratory failure. Although recombinant human soluble thrombomodulin (rTM) consists of three domains (D1-3), is reported to attenuate systemic inflammation through the N-terminal lectin-like domain (D1), anticoagulant domain (D2) may exacerbate coagulopathy after CPB. We investigated the potential of selective D1 against CPB-mediated ALI free from anticoagulant effects using a rat CPB model.

METHODS

Rats were divided into three groups: control (CPB alone, n = 5), D1 (CPB + D1, n = 4), and D123 (CPB + D123, n = 6). D1 or D123 was administrated to the rats of each group before CPB establishment. Blood samples are collected before, during and after CPB. Blood coagulability was assessed by a coagulation analyzer. Lung samples are collected at 1 h after the termination of CPB for histological analyses.

RESULTS

D123 group exhibited significantly prolonged glass beads-activated clotting time with heparinase after CPB compared to that in control group, whereas no significant prolongation in control and D1 group (control vs. D1 vs. D123: 65.4 ± 9.2 vs. 65.3 ± 10.9 vs. 83.5 ± 4.6 s, p = 0.036 [control vs. D123], 0.99 [control vs. D1]) indicating the absence of anticoagulant activities of D1. Histological studies revealed less congestion, edema, inflammation, and hemorrhage in both D1 and D123 groups compared to those in control group indicating protective effects of both D1 and D123 against ALI mediated by CPB.

CONCLUSIONS

N-terminal lectin-like domain of rTM may reduce the risk of ALI without anticoagulant effects.

Evaluation of two intensive care models in relation to successful extubation after cardiac surgery

OBJECTIVE

To compare outcomes between intensivist-directed and cardiac surgeon-directed care delivery models.

DESIGN

This retrospective, historical-control study was performed in a cohort of adult cardiac surgical patients at Zhongshan Hospital (Fudan University, China). During the first phase (March to August 2015), cardiac surgeons were in charge of postoperative care while intensivists were in charge during the second phase (September 2015-June 2016). Both phases were compared regarding successful extubation rate, intensive care unit (ICU) length of stay (LOS), and in-hospital mortality.

SETTING

Tertiary Zhongshan Hospital (Fudan University, China).

PATIENTS

Consecutive adult patients admitted to the cardiac surgical ICU (CSICU) after heart surgery.

INTERVENTIONS

Phase I patients treated by cardiac surgeons, and phase II patients treated by intensivists.

MAIN VARIABLES OF INTEREST

Successful extubation, ICU LOS and in-hospital mortality.

RESULTS

A total of 1792 (phase I) and 3007 patients (phase II) were enrolled. Most variables did not differ significantly between the two phases. However, patients in phase II had a higher successful extubation rate (99.17% vs. 98.55%; p=0.043) and a shorter median duration of mechanical ventilation (MV) (18 vs. 19h; p<0.001). In relation to patients with MV duration >48h, those in phase II had a comparatively higher successful extubation rate (p=0.033), shorter ICU LOS (p=0.038) and a significant decrease in in-hospital mortality (p=0.039).

CONCLUSIONS

The intensivist-directed care model showed improved rates of successful extubation and shorter MV durations after cardiac surgery.

Healthcare utilization and costs of cardiopulmonary complications following cardiac surgery in the United States

PURPOSE

This study examined postoperative heart failure (HF) and respiratory failure (RF) complications and related healthcare utilization for one year following cardiac surgery.

METHODS

This study identified adult patients undergoing isolated coronary artery bypass graft (CABG) and/or valve procedures from the Cerner Health Facts® database. It included patients experiencing postoperative HF or RF complications. We quantified healthcare utilization using the frequency of inpatient admissions, emergency department (ED) visits with or without hospital admission, and outpatient visits. We then determined direct hospital costs from the determined healthcare utilization. We analyzed trends over time for both HF and RF and evaluated the association between surgery type and HF complication.

RESULTS

Of 10,298 patients with HF complications, 1,714 patients (16.6%) developed persistent HF; of the 10,385 RF patients, 175 (1.7%) developed persistent RF. Healthcare utilization for those with persistent complications over the one-year period following index hospital discharge comprised an average number of the following visit types: Inpatient (1.49 HF; 1.55 RF), Outpatient (2.02, 0.51), ED without hospital admission (0.33, 0.13), ED + Inpatient (0.08, 0.06). Per patient annual costs related to persistent complications of HF and RF were $20,857 and $30,745, respectively. There was a significant association between cardiac surgical type and the incidence of HF, with risk for isolated valve procedures (adjusted OR 2.60; 95% CI: 2.35-2.88) and CABG + valve procedures (adjusted OR 2.38; 95% CI: 2.17-2.61) exceeding risk for isolated CABG procedures.

CONCLUSIONS

This study demonstrates that HF and RF complication rates post cardiac surgery are substantial, and complication-related healthcare utilization over the first year following surgery results in significant incremental costs. Given the need for both payers and providers to focus on healthcare cost reduction, this study fills an important gap in quantifying the mid-term economic impact of postoperative cardiac surgical complications.

Postoperative acute respiratory failure in cardiac surgery

OBJECTIVE

To evaluate incidence, causes and outcomes of acute respiratory failure (ARF) in patients after cardiac and aortic surgery.

MATERIAL AND METHODS

A retrospective trial included 3972 patients after elective cardiovascular procedures for the period 2013-2017. Inclusion criterion: sustained reduction of pulmonary function (PaO₂/FiO₂<300 mm Hg) in the postoperative period required mechanical ventilation or non-invasive positive pressure mask ventilation for at least 24 h.

RESULTS

ARF developed in 138 (3.5%) cases. It was observed after aortic surgery as a rule (11.2%). Other operations were followed by ARF in 1-3.5% of cases. Incidence of ARF was less after off-pump coronary artery bypass surgery compared with on-pump interventions (1.6 vs. 3.5%, p=0.0469). Acute respiratory distress syndrome was the main reason of ARF (n=37, 26.8%). ARF as a consequence of neurological complications were observed in 25 (18.1%) patients. Exacerbation of COPD and bronchial asthma occurred in 23 (16.1%) patients, paresis of the diaphragm - in 15 (11.7%). In 15 (10.8%) patients, ARF was caused by pneumonia, in 12 (8.7%) cases - pulmonary congestion, in 10 (7.2%) patients - lung injury and haemothorax. Overall ARDS-associated mortality was 21.6%; 15.1% of patients with mild and moderate ARDS died. Severe ARDS was followed by unfavorable outcome in 75% of patients. Nosocomial pneumonia was found in 40.6%, there were no fatal outcomes from this complication.

CONCLUSION

Acute respiratory failure developed in 3.5% of cardiac patients and was common thoracic and thoracoabdominal aortic surgery. The leading cause of mortality was ARDS (mortality rate 15.1% in mild and moderate syndrome, 75% in severe course of ARDS). Nosocomial pneumonia was diagnosed in 1.4% of patients and was not fatal.

Significance of Interstitial Lung Disease on Outcomes Following Cardiac Surgery

Interstitial lung disease (ILD) is a known risk factor for noncardiac surgery due to acute pulmonary exacerbations but its impact after cardiac surgery is not known. We examined perioperative outcomes and risk factors for long-term survival in ILD patients who underwent cardiac surgery. From January 2002 to June 2017, 294 cardiac surgery patients with a previous ILD diagnosis, including 75 patients with idiopathic pulmonary fibrosis (IPF), were identified. A comparison cohort of 1,481 non-ILD patients was selected based on a priori variables. Long-term survival was evaluated using Cox proportional hazard modeling. Median follow-up was 6.4 years. ILD patients had higher postoperative mortality, reintubation rates, longer intensive care unit stay, and higher 30-day readmission rates (all p <0.05). Kaplan-Meier estimates of survival at 1, 5, and 10 years were 89%, 62%, and 37% for the non-IPF ILD cohort, 89%, 50%, and 13% for the IPF cohort, and 95%, 82%, and 67% for the comparison cohort, respectively (overall p <0.001). These significant differences in survival persisted in our risk-adjusted survival analysis. Adjusted survival analysis identified IPF (hazard ratio 3.04) and ILD (non-IPF; hazard ratio 1.78) as significant contributors to all-cause mortality. However, there were no changes in pulmonary function tests after 48 months postprocedure. In conclusion, ILD patients who underwent cardiac surgery have increased operative mortality, reintubation rates, longer intensive care unit, and higher 30-day readmissions compared with non-ILD patients. Moreover, severity of ILD, especially in IPF, appears to be associated with shorter long-term survival. In these patients, pulmonary risk stratification and multidisciplinary team approach are crucial.

Low hematocrit levels: a risk factor for long-term outcomes in patients requiring prolonged mechanical ventilation after cardiovascular surgery. A retrospective study

While low-risk patients who undergo elective surgery can tolerate low hematocrit levels, the benefits of higher hematocrit levels might outweigh the risk of transfusion in high-risk patients. Therefore, this study aimed to evaluate the effects of perioperative hematocrit levels on mortality in patients requiring prolonged mechanical ventilation (PMV) after a cardiovascular surgery. This single-center retrospective cohort study was conducted on 172 patients who underwent cardiovascular surgery with cardiopulmonary bypass or off-pump coronary artery bypass grafting and required PMV for ≥72 hours in the intensive care unit (ICU) from 2008 to 2012 at the Yokohama City University Medical Center in Yokohama, Japan. Patients were classified according to hematocrit levels on ICU admission: high (≥30%) and low (<30%) groups. Of 172 patients, 86 were included to each of the low-hematocrit and high-hematocrit groups, with median hematocrit levels (first to third quartiles) of 27.4% (25.4%–28.7%) and 33.0% (31.3%–35.5%), respectively. The difference in survival rates was significant between the two groups using the log-rank test (HR 0.55, 95% CI 0.32 to 0.95, p=0.033). Cox regression analysis revealed that ≥30% increase in hematocrit levels on ICU admission was significantly associated with decreased long-term mortality (HR 0.40, 95% CI 0.20 to 0.80, p=0.0095). Lower hematocrit levels on ICU admission was a risk factor for increased long-term mortality, and higher hematocrit levels might outweigh the risk of transfusion in patients requiring PMV after a cardiovascular surgery.

Aortic root enlargement to mitigate patient-prosthesis mismatch: do early adverse events justify reluctance?†

OBJECTIVES:

Concomitant aortic root enlargement (ARE) at the time of surgical aortic valve replacement can be performed to avoid patient-prosthesis mismatch, an important predictor of adverse long-term outcome.

METHODS:

We performed a single-centre, retrospective analysis of 4120 patients receiving isolated aortic valve replacement, of whom 171 (4%) had concomitant ARE between January 2005 and December 2015. The analysis of postoperative outcome and early mortality was performed. Owing to inequality of the groups, patients were matched 1:1.

RESULTS:

The mean age of all 4120 patients was 68.8 ± 10.5 years, and comorbidities were equally balanced after matching. The mean aortic cross-clamp time, cardiopulmonary bypass time and total operative time were prolonged by 19, 20 and 27 min in the ARE group, respectively. Early mortality was not statistically significantly different with 1.4% in the surgical aortic valve replacement and 1.8% in the ARE group. Postoperative complications were <5% in all matched 338 patients: bleeding (3% vs 3%), pericardial effusion (3.0% vs 4.2%), sternal instability (1.8% vs 0%) and sternal wound infection (3.0% vs 1.2%). A significant higher number of patients had respiratory failure after ARE (unmatched: 17.1% vs 9.9%, P < 0.001; matched: 18.3% vs 9.5%, P = 0.028). Factors independently associated with overall mortality were age [hazard ratio (HR) 1.71], chronic obstructive pulmonary disease (HR 1.47), diabetes (HR 1.82), atrial fibrillation (HR 2.14) and postoperative respiratory failure (HR 2.84).

CONCLUSIONS:

ARE can be performed safely in experienced centres with no significant increase in the risk of early postoperative surgical complications and early mortality. However, the surgeon and the intensive care unit team should be aware of an increased risk for postoperative respiratory failure in ARE patients.

The Effects of On-Pump and Off-Pump Coronary Artery Bypass Surgery on Respiratory Function in the Early Postoperative Period

BACKGROUND:

Respiratory complications are common after cardiac surgery and the use of extracorporeal circulation is one of the main causes of lung injury. We hypothesized a better postoperative respiratory function in off-pump coronary artery bypass grafting (OPCABG) as compared with "on-pump coronary artery bypass grafting" (ONCABG).

METHODS:

This is a retrospective, single-center study at a cardiothoracic intensive care unit (ICU) in a tertiary university hospital. Consecutive data on 339 patients undergoing elective CABG (n = 215 ONCABG, n = 124 OPCABG) were collected for 1 year from the ICU electronic medical records. We compared respiratory variables (Pao2, Pao2/Fio2 ratio, Sao2, and Paco2) at 7 predefined time points (ICU admission, postoperative hours 1, 3, 6, 12, 18, and 24). We also evaluated time to extubation, rates of reintubation, and use of noninvasive ventilation (NIV). We used mixed-effects linear regression models (with time as random effect for clustering of repeated measures) adjusted for a predetermined set of covariates.

RESULTS:

The values of Pao2 and Pao2/Fio2 were significantly higher in the OPCABG group only at ICU admission (mean differences: 9.7 mm Hg, 95% confidence interval [CI] 3.1-16.2; and 27, 95% CI 6.1-47.7, respectively). The OPCABG group showed higher Paco2, overall ( P = .02) and at ICU admission (mean difference 1.8 mm Hg, 95% CI: 0.6-3), although mean values were always within normal range in both groups. No differences were seen in Sao2 values, time to extubation, rate of reintubation rate, and use of postoperative NIV. Extubation rate was higher in OPCABG only at postoperative hour 12 (92% vs ONCABG 82%, P = .02).

CONCLUSION:

The OPCABG showed only marginal improvements of unlikely clinical meaning in oxygenation as compared to ONCABG in elective low-risk patients.

Feasibility of On-table Extubation After Cardiac Surgery with Cardiopulmonary Bypass: A Randomized Clinical Trial

BACKGROUND

The use of short-acting anesthetics, muscle relaxation, and anesthesia depth monitoring allows maintaining sufficient anesthesia depth, fast recovery, and extubation of the patients in the operating room (OR). We evaluated the feasibility of extubation in the OR in cardiac surgery.

METHODS

This clinical trial was performed on 100 adult patients who underwent elective noncomplex cardiac surgery using cardiopulmonary bypass. Additional to the routine monitoring, the patients' depth of anesthesia and neuromuscular blocked were assessed by bispectral index and nerve stimulator, respectively. In the on-table extubation (OTE) group (n = 50), a limited dose of sufentanil (0.15 µg/kg/h) and inhalational anesthetics were used for early waking. In the control group (n = 50), the same anesthesia-inducing drugs were used but the dose of sufentanil during the operation was 0.7 - 0.8 µg/kg/h. After the operation, cardiorespiratory parameters and ICU stay were documented.

RESULTS

Demographic and clinical variables were comparable in both study groups. In the OTE group, we failed to extubate two patients in the OR (success rate of 96%). There were no significant differences between the two groups in terms of systolic and diastolic blood pressure at the time of entering the ICU (P > 0.05). Heart rate was lower in the OTE than in the control group at ICU admission (89.4 ± 13.1 vs. 97.6 ± 12.0 bpm; P = 0.008). The ICU stay time was lower in the OTE group (34 (21.5 - 44) vs. 48 (44 - 60) h; P = 0.001).

CONCLUSIONS

Combined inhalational-intravenous anesthesia along with using multiple anesthesia monitoring systems allows reducing the dose of total anesthetics and maintaining adequate anesthesia depth during noncomplex cardiac surgery with cardiopulmonary bypass. Thus, extubation of the trachea in the OR is feasible in these patients.

Bilateral sternal infusion of ropivacaine and length of stay in ICU after cardiac surgery with increased respiratory risk: A randomised controlled trial

BACKGROUND

The continuous bilateral infusion of a local anaesthetic solution around the sternotomy wound (bilateral sternal) is an innovative technique for reducing pain after sternotomy.

OBJECTIVE

To assess the effects of the technique on the need for intensive care in cardiac patients at increased risk of respiratory complications.

DESIGN

Randomised, observer-blind controlled trial.

SETTING

Single centre, French University Hospital.

PATIENTS

In total, 120 adults scheduled for open-heart surgery, with one of the following conditions: age more than 75 years, BMI >30 kg m, chronic obstructive pulmonary disease, active smoking habit.

INTERVENTION

Either a bilateral sternal infusion of 0.2% ropivacaine (3 ml h through each catheter; 'intervention' group), or standardised care only ('control' group). Analgesia was provided with paracetamol and self-administered intravenous morphine.

MAIN OUTCOME MEASURES

The length of time to readiness for discharge from ICU, blindly assessed by a committee of experts.

RESULTS

No effect was found between groups for the primary outcome (P = 0.680, intention to treat); the median values were 42.4 and 37.7 h, respectively for the control and intervention groups (P = 0.873). Similar nonsignificant trends were noted for other postoperative delays. Significant effects favouring the intervention were noted for dynamic pain, patient satisfaction, occurrence of nausea and vomiting, occurrence of delirium or mental confusion and occurrence of pulmonary complications. In 12 patients, although no symptoms actually occurred, the total ropivacaine plasma level exceeded the lowest value for which neurological symptoms have been observed in healthy volunteers.

CONCLUSION

Because of a small size effect, and despite significant analgesic effects, this strategy failed to reduce the time spent in ICU.

TRIAL REGISTRATION

EudraCT (N°: 2012-005225-69); ClinicalTrials.gov (NCT01828788).

Regulatory T cells may play a protection role in postoperative pulmonary dysfunction in rheumatic heart disease

Background

Postoperative pulmonary dysfunction (PPD) is a common complication observed in patients after cardiac surgery with cardiopulmonary bypass (CPB). The underlying mechanism regulating lung injury after CPB is unclear. However, since the involvement of regulatory T (Treg) cells and T helper 17 (Th17) cells in immune responses has been well established, in this study, we investigated the contribution of these lymphocyte subsets to the development of PPD after CPB.

Methods

Fifty-six rheumatic heart disease (RHD) patients' blood samples were collected at different time points before and after surgery. The samples were analyzed by flow cytometry to quantify cells and by enzyme-linked immunosorbent assay (ELISA) to measure the cytokine content. In addition, the inhibitory function of Treg cells of ten patients was tested before and after surgery.

Results

We showed that a decreased percentage of Treg cells and reduced Treg/Th17 ratio before anesthesia and after neutralization are meaningful predictors of severe PPD (AUC 0.722, 95% CI: 0.557 to 0.888; 0.787, 95% CI: 0.639 to 0.934; 0.751, 95% CI: 0.593 to 0.919; 0.551, 95% CI: 0.366 to 0.735). Interestingly, both the percentage of Treg cells and their suppressive effect on effector T lymphocyte (Teff) cells were increased after CPB, and both effects may play a protective role in PPD. By contrast, severe PPD was associated with increased IL-17A levels.

Conclusions

The increased proportion of Treg cells in the CD4⁺ T cell population and higher ratio of Treg/Th17 before anesthesia induction and 30 min after heparin neutralization can partially protect patients from a severe inflammatory response and PPD.

Risk factors for noninvasive ventilation failure in patients with post-extubation acute respiratory failure after cardiac surgery

Background

The effect of noninvasive ventilation (NIV) in patients with acute respiratory failure (ARF) after cardiac surgery is controversial. This study identified the feasibility of NIV and assessed the risk factors of NIV failure in patients with ARF after cardiac surgery.

Methods

We retrospectively reviewed data from 112 patients with ARF requiring NIV and categorized them into the NIV failure and success groups. Patient data were extracted for further analysis, the primary outcomes were the need for endotracheal intubation and NIV-related in-hospital mortality. The risk factors for NIV failure in patients with post-extubation ARF was analyzed.

Results

The median time from extubation to NIV was 11 hours. No difference in the EuroSCORE existed between the two groups. NIV failed in 38.4% of the patients. The NIV failure group had a higher in-hospital mortality and stay at the longer intensive care unit (ICU). Most cases of NIV failure occurred within 1-48 hours of the treatment. The main causes of early NIV failure were a weak cough reflex and/or excessive secretions and hemodynamic instability. A Sequential Organ Failure Assessment (SOFA) score ≥10.5, vasoactive-inotropic score ≥6, and pneumonia were predictors of NIV failure, whereas a body mass index (BMI) ≥25.0 kg/m² predicted NIV success.

Conclusions

NIV was effective in the study population. Multiple organ dysfunction, pneumonia, and significant inotropic drug support before NIV were associated with NIV failure, whereas a BMI ≥25 kg/m² was a predictor of NIV success.

Ventilator-associated pneumonia in patients assisted by veno-arterial extracorporeal membrane oxygenation support: Epidemiology and risk factors of treatment failure

INTRODUCTION

Ventilator-associated pneumonia (VAP) is frequent in Intensive Care Unit (ICU) patients. In the specific case of patients treated with Veno-Arterial Extracorporeal Membrane Oxygenation Support (VA-ECMO), VAP treatment failures (VAP-TF) have been incompletely investigated.

METHODS

To investigate the risk factors of treatment failure (VAP-TF) in a large cohort of ICU patients treated with VA-ECMO, we conducted a retrospective study in a Surgical ICU about patients assisted with VA-ECMO between January 1, 2013, and December 31, 2014. Diagnosis of VAP was confirmed by a positive quantitative culture of a respiratory sample. VAP-TF was defined as composite of death attributable to pneumonia and relapse within 28 days of the first episode.

RESULTS

In total, 152 patients underwent ECMO support for > 48h. During the VA-ECMO support, 85 (55.9%) patients developed a VAP, for a rate of 60.6 per 1000 ECMO days. The main pathogens identified were Pseudomonas aeruginosa and Enterobacteriaceae. VAP-TF occurred in 37.2% of patients and was associated with an increased 28-day mortality (Hazard Ratio 3.05 [1.66; 5.63], P<0.001), and VA-ECMO assistance duration (HR 1.47 [1.05-2.05], P = 0.025). Risk factors for VAP-TF were renal replacement therapy (HR 13.05 [1.73; 98.56], P = 0.013) and documentation of Pseudomonas aeruginosa (HR 2.36 [1.04; 5.35], P = 0.04).

CONCLUSIONS

VAP in patients treated with VA-ECMO is associated with an increased morbidity and mortality. RRT and infection by Pseudomonas aeruginosa appear as strong risks factors of treatment failure. Further studies seem necessary to precise the best antibiotic management in these patients.

Oxygenation impairment after total arch replacement with a stented elephant trunk for type-A dissection

OBJECTIVE

To study the risk factors of oxygenation impairment in patients with type-A acute aortic dissection who underwent total arch replacement with a stented elephant trunk.

METHODS

In this study, 169 consecutive patients were enrolled who were diagnosed with type-A acute aortic dissection and underwent a total arch replacement procedure at the Qilu Hospital of Shandong University between January 2015 and February 2017. Postoperative oxygenation impairment was defined as arterial oxygen partial pressure/inspired oxygen fraction ≤ 200 with positive end expiratory pressure ≥ 5 cm H₂O that occurred within 72 hours of surgery. Perioperative clinical characteristics of all patients were collected and univariable analyses were performed. Risk factors associated with oxygenation impairment identified by univariable analyses were included in the multivariable regression analysis.

RESULTS

The incidence of postoperative oxygenation impairment was 48.5%. Postoperative oxygenation impairment was associated with prolonged mechanical ventilation time, intensive care unit stay, and hospital stay. Multivariable regression analysis demonstrated that body mass index (odds ratio [OR], 1.204; 95% confidence interval [CI], 1.065-1.361; P = .003), preoperative oxygenation impairment (OR, 9.768; 95% CI, 4.159-22.941; P < .001), preoperative homocysteine (OR, 1.080; 95% CI, 1.006-1.158; P = .032), circulatory arrest time (OR, 1.123; 95% CI, 1.044-1.207; P = .002), and plasma transfusion (OR, 1.002; 95% CI, 1.001-1.003; P = .002) were significantly associated with postoperative oxygenation impairment.

CONCLUSIONS

Postoperative oxygenation impairment is a common complication of surgery for type-A acute aortic dissection. Body mass index, preoperative oxygenation impairment, preoperative homocysteine, circulatory arrest time, and plasma transfusion were independent risk factors for oxygenation impairment after a total arch replacement procedure.

Risk factors for hypoxemia following surgical repair of acute type A aortic dissection

Objectives

To identify the risk factors for hypoxaemia following surgical repair of acute type A aortic dissection.

Methods

This was a retrospective study of patients treated between October 2013 and December 2014 at the Department of Cardiovascular Surgery, Anzhen Hospital, China. Univariable and multivariable analyses were performed on the clinical data of 160 patients with acute type A dissection and who underwent ascending aortic and arch replacement under deep hypothermic circulatory arrest.

Results

Hypoxaemia occurred in 30% (48/160) of patients (age: 49 ± 7.9 years; 40 males, 83.3%). The duration of ventilation and the lengths of intensive care unit and hospital stays were significantly longer in patients with hypoxemia (77.9 ± 56.0 vs 16.5 ± 11.5 h, P < 0.0001; 6.0 ± 2.3 vs 2.0 ± 1.2 days, P = 0.001; 18.1 ± 6.3 vs 13.5 ± 4.7 days, P = 0.0012; respectively). The difference in operative mortality was not statistically significant between the hypoxaemia and non-hypoxaemia groups (6.25% vs 3.57%, P = 0.351). The independent risk factors of postoperative hypoxaemia were time from symptom onset to surgery ≤72 h [odds ratio, 3.63; 95% confidence interval, 1.31-10.02; P = 0.013], preoperative PaO2/FiO2 ≤300 (odds ratio, 15.30; 95% CI, 5.52-42.43; P < 0.001), preoperative white blood cell count >15 000/μl (odds ratio, 9.79; 95% CI, 2.47-38.87; P = 0.001); and deep hypothermic circulatory arrest time >25 min (odds ratio, 3.26; 95% CI, 1.18-8.99; P = 0.023).

Conclusions

Time from symptom onset to surgery ≤72 h, preoperative PaO2/FiO2 ≤300, white blood cell count >15 000/μl and deep hypothermic circulatory arrest time >25 min were found to be independently associated with hypoxaemia after surgery for acute type A aortic dissection.

Hemodynamic challenge to early mobilization after cardiac surgery: A pilot study

Background:

Active mobilization is a key component in fast-track surgical strategies. Following major surgery, clinicians are often reluctant to mobilize patients arguing that circulatory homeostasis would be impaired as a result of myocardial stunning, fluid shift, and autonomic dysfunction.

Aims:

We examined the feasibility and safety of a mobilization protocol 12–24 h after elective cardiac surgery.

Setting and Design:

This observational study was performed in a tertiary nonacademic cardiovascular Intensive Care Unit.

Materials and Methods:

Over a 6-month period, we prospectively evaluated the hemodynamic response to a two-staged mobilization procedure in 53 consecutive patients. Before, during, and after the mobilization, hemodynamics parameters were recorded, including the central venous oxygen saturation (ScvO₂), lactate concentrations, mean arterial pressure (MAP), heart rate (HR), right atrial pressure (RAP), and arterial oxygen saturation (SpO₂). Any adverse events were documented.

Results:

All patients successfully completed the mobilization procedure. Compared with the supine position, mobilization induced significant increases in arterial lactate (34.6% [31.6%, 47.6%], P = 0.0022) along with reduction in RAP (−33% [−21%, −45%], P < 0.0001) and ScvO₂ (−7.4% [−5.9%, −9.9%], P = 0.0002), whereas HR and SpO₂ were unchanged. Eighteen patients (34%) presented a decrease in MAP > 10% and nine of them (17%) required treatment. Hypotensive patients experienced a greater decrease in ScvO₂ (−18 ± 5% vs. −9 ± 4%, P = 0.004) with similar changes in RAP and HR. All hemodynamic parameters, but arterial lactate, recovered baseline values after resuming the horizontal position.

Conclusions:

Early mobilization after cardiac surgery appears to be a safe procedure as far as it is performed under close hemodynamic and clinical monitoring in an intensive care setting.

Ten Years Experiences With Preoperative Evaluation Clinic for Day Admission Cardiac and Major Vascular Surgical Patients: Model for "Perioperative Anesthesia and Surgical Home"

Admission on the day of surgery for elective cardiac and noncardiac surgery is the prevalent practice in North America and Canada. This approach realizes medical, psychological and logistical benefits, and its success is predicated on an effective outpatient preoperative evaluation. The establishment of a highly functional preoperative clinic with a comprehensive set up and efficient logistical pathways is invaluable. This notion in recent years has included the entire perioperative period, and the concept of a perioperative anesthesia/surgical home (PASH) is gaining popularity. The anesthesiologists as perioperative physicians can organize and lead the entire process from the preoperative evaluation, through the hosptial discharge. The functions of the PASH include preoperative optimization of medical conditions and psychological preparation of the patients and their support system; the care in the operating room and intensive care unit; pain management; respiratory therapy; cardiac rehabilitation; and specialized nutrition. Along with oversight of the medical issues, the preoperative visit is an opportune time for counseling, clarification of expectations and discussion of research, as well as for utilization of various informatics systems to consolidate the pertinent information and distribute it to relevant health care providers. We review the scientific foundation and practical applications of a preoperative visit and share our experience with the development of the preoperative evaluation clinic, designed specifically for cardiac and major vascular patients scheduled for day admission surgery. The ultimate goal of preoperative evaluation clinic is to ensure a safe, efficient, and cost-effective perioperative care for patients undergoing a complex type of surgery.

[Cardiopulmonary bypass duration as predictor of immediate results after cardiac surgery]

It was analyzed the results of treatment of 152 patients who underwent heart valve surgery. Depending on cardiopulmonary bypass (CPB) duration patients were divided into 4 groups: the 1st--up to 90 min, the 2nd--90-120 min, the 3rd--120-180 min, the 4th--more than 180 min. Severity of initial comorbidities was comparable in all groups. It was revealed that CPB duration effects on intraoperative blood loss, incidence of acute renal failure, encephalopathy, use of inotropic and angiotonic support (p<0.05). Accession of CPB duration was associated with increased number of postoperative complications in all groups (p<0.05). "Critical periods" of CPB for every type of postoperative complications are defined.

Predictors of prolonged mechanical ventilation after open heart surgery

Introduction: Due to the importance of prolonged mechanical ventilation (PMV) as a postoperative complication, predicting "high-risk" patients by identifying predisposing risk factors is of important issue. The present study was aimed to identify perioperative variables associated with PMV in patients undergoing open heart surgery.

Methods: A total of 743 consecutive patients, American Society of Anesthesiologists (ASA) physical status class III, who were scheduled to undergo open heart surgery using cardiopulmonary bypass were included in this observational study. Perioperative variables were compared between the patients with and without PMV, as defined by an extubation time of >48 h.

Results: PMV occurred in 45 (6.1%) patients. On univariate analysis, pre-operative variables; including gender, history of chronic obstructive pulmonary disease (COPD); chronic kidney disease and endocarditis, intra-operative variables; including type of surgery, operation time, pump time, transfusion in operating room and postoperative variables; including bleeding and inotrope-dependency were significantly different between patients with and without PMV (all P<0.001, except for COPD and transfusion in operating room; P=0.004 and P=0.017, respectively).

Conclusion: Our findings reinforce that risk stratification for predicting delayed extubation should be an important aspect of preoperative clinical evaluation in all anesthesiology settings.

Variation in tracheal reintubations among patients undergoing cardiac surgery across Washington state hospitals

OBJECTIVES

The objectives of this study were to examine the variation in reintubations across Washington state hospitals that perform cardiac surgery, and explore hospital and patient characteristics associated with variation in reintubation.

DESIGN

Retrospective cohort study.

SETTING

All nonfederal hospitals performing cardiac surgery in Washington state.

PARTICIPANTS

A total of 15,103 patients undergoing coronary artery bypass grafting or valvular surgery between January 1, 2008 and September 30, 2011.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patient and hospital characteristics were compared between hospitals that had a reintubation frequency ≥5% or<5%. Multivariate logistic regression was used to compare the odds of reintubation across the hospitals. The authors tested for heterogeneity of odds of reintubation across hospitals by performing a likelihood ratio test on the hospital factor. After adjusting for patient-level characteristics and procedure type, significant heterogeneity in reintubations across hospitals was present (p = 0.005). This exploratory analyses suggested that hospitals with lower reintubations were more likely to have more acute care days and teaching intensive care units (ICU).

CONCLUSIONS

After accounting for patient and procedure characteristics, significant heterogeneity in the relative odds of requiring reintubation was present across 16 nonfederal hospitals performing cardiac surgery in Washington state. The findings suggested that greater hospital volume and ICU teaching status were associated with fewer reintubations.

Long-Term Mortality After Pneumonia in Cardiac Surgery Patients

Background:

The role that intensive care unit (ICU)-acquired pneumonia plays in the long-term outcomes of cardiac surgery patients is not well known. This study examined the association of pneumonia with in-hospital mortality and long-term mortality after adult cardiac surgery.

Methods:

A total of 2750 patients admitted to our ICU after cardiac surgery from January 2003 to December 2009 are the basis for this observational study. Patients who developed ICU-acquired pneumonia were matched with patients without it in a 1:2 ratio. The matching criteria were age, urgent or scheduled surgery, surgical procedure, and the propensity score for pneumonia. Multiple regression analysis was used to find predictors of hospital mortality. The relationship between pneumonia and long-term survival was analyzed with Kaplan-Meier survival estimates and a risk-adjusted Cox proportional regression model for patients discharged alive from hospital.

Results:

Pneumonia was diagnosed in 32 (1.2%) patients and there were 19 cases per 1000 days of mechanical ventilation. Patients with pneumonia had a significantly higher hospital mortality rate (28% vs 6.2%, P = .003) and a higher mortality at the end of follow-up (53% vs 19%, P < .0001) than those without it. Regression analysis showed that pneumonia was a strong predictor of hospital mortality. Five-year survival was as follows: pneumonia, 62%; control, 81%; and cohort patients, 91%. The Cox model showed that, after adjusting for confounding factors, patients with pneumonia (hazard ratio = 3.96, 95% confidence interval [CI]: 1.41-11.14) had poorer long-term survival.

Conclusion:

Pneumonia remains a serious complication in patients operated for cardiac surgery and is associated with increased hospital mortality and reduced long-term survival.

Percutaneous Tracheostomy Can be Safely Performed in Patients with Uncorrected Coagulopathy after Cardiothoracic Surgery

Objective

It is a common situation after cardiothoracic surgery that a tracheostomy is required for patients who are coagulopathic or on therapeutic anticoagulation. We present our results of percutaneous tracheostomy with uncorrected coagulopathy.

Methods

Between 2007 and 2012, a total of 149 patients in our Cardiothoracic Surgical Intensive Care Unit underwent percutaneous tracheostomy using the Ciaglia Blue Rhino system (Cook Medical, Bloomington, IN USA). The patients were divided into coagulopathic (platelets, ≤50,000; international normalized ratio of prothrombin time, ≥1.5; and/or partial thromboplastin time, ≥50) and noncoagulopathic groups. Coagulopathy, if present before percutaneous tracheostomy, was not routinely corrected.

Results

A total of 75 patients (49%) were coagulopathic. Twenty-one patients (14%) had two or more criteria. The coagulopathic patients had a lower platelet count [108 (106) vs 193 (111) (thousands), P < 0.001], with the lowest of 10; higher international normalized ratio of prothrombin time [1.7 (0.6) vs 1.2 (0.1), P < 0.001], with the highest of 5.3; longer partial thromboplastin time [40 (13) vs 33 (7) seconds, P < 0.001], with the longest of 85; and higher total bilirubin [4.6 (7.3) vs 1.9 (3.3) mg/dL, P = 0.005]. Patient demographics and comorbidities were comparable between the groups. No patients had overt bleeding. One coagulopathic patient (1.3%) had clinical oozing treated with packing, as opposed to zero in the noncoagulopathic patients ( P = 1.00). There were no patients with posttracheostomy mediastinitis or late tracheal stenosis.

Conclusions

Uncorrected coagulopathy and therapeutic anticoagulation did not increase bleeding risk for percutaneous tracheostomy in our cardiothoracic surgical patients.

Risk factors of prolonged mechanical ventilation following open heart surgery: what has changed over the last decade?

OBJECTIVE

To identify the risk factors for prolonged invasive mechanical ventilation after open heart surgery in Pakistan.

DESIGN

This study is based on retrospective analysis of database.

PLACE AND DURATION

We conducted study of all patients who underwent open heart surgery at CPE Institute of Cardiology, Multan from March 2009 to May 2011.

PATIENTS & METHODS

The data was retrieved from the database in the form of electronic spreadsheet which was then analyzed using SPSS software. The patients with incomplete data entries were removed from the analysis resulting in a set of 1,617 patients. The data of each patient consisted of 65 preoperative, operative and postoperative variables. The data was summarized as means, medians and standard deviations for numeric variables and frequencies and percentages or categoric variables. These risk factors were compared using Chi-sqaure test. Their ODDs ratios and 95% confidence intervals of ODD's Ratios and P values were calculated.

RESULTS

Out of a total of 1,617 patients, 77 patients (4.76%) had prolonged ventilation for a cumulated duration of more than over 24 hours. Preoperative renal failure, emphysema, low EF (<30%), urgent operation, preoperative critical state, prolonged bypass time, prolonged cross clamp time, complex surgical procedures and peri-operative myocardial infarction were found to be risk factors for PIMV. Old age, female gender, advanced ASA class, advanced NYHA class, diabetes mellitus, smoking, history of COPD, redo surgery, left main stenosis, obesity and use of intra-aortic balloon pump were not found to have significant ODDs ratios for PIMV. The patients with prolonged ventilation had significantly high mortality i.e. 32.47% while the normal ventilation group had 0.32% overall mortality.

CONCLUSIONS

Many of the previously considered risk factors for prolonged ventilation after open heart study are no more significant risk factors. However, prolonged ventilation continues to be associated with very high mortality.

Soluble isoform of the receptor for advanced glycation end products as a biomarker for postoperative respiratory failure after cardiac surgery

Purpose

Postoperative respiratory failure is a major problem which can prolong the stay in the intensive care unit in patients undergoing cardiac surgery. We measured the serum levels of the soluble isoform of the receptor for advanced glycation end products (sRAGE), and we studied its association with postoperative respiratory failure.

Methods

Eighty-seven patients undergoing elective cardiac surgery were enrolled in this multicenter observational study in three university hospitals. Serum biomarker levels were measured perioperatively, and clinical data were collected for 7 days postoperatively. The duration of mechanical ventilation was studied for 28 days.

Results

Serum levels of sRAGE elevated immediately after surgery (median, 1751 pg/mL; interquartile range (IQR) 1080–3034 pg/mL) compared with the level after anesthetic induction (median, 884 pg/mL; IQR, 568–1462 pg/mL). Postoperative sRAGE levels in patients undergoing off-pump coronary artery bypass grafting (median, 1193 pg/mL; IQR 737–1869 pg/mL) were significantly lower than in patients undergoing aortic surgery (median, 1883 pg/mL; IQR, 1406–4456 pg/mL; p = 0.0024) and valve surgery (median, 2302 pg/mL; IQR, 1447–3585 pg/mL; p = 0.0005), and postoperative sRAGE correlated moderately with duration of cardiopulmonary bypass (r_s = 0.44, p<0.0001). Receiver operating characteristic curve analysis demonstrated that postoperative sRAGE had a predictive performance with area under the curve of 0.81 (95% confidence interval 0.71–0.88) for postoperative respiratory failure, defined as prolonged mechanical ventilation >3 days. The optimum cutoff value for prediction of respiratory failure was 3656 pg/mL, with sensitivity and specificity of 62% and 91%, respectively.

Conclusions

Serum sRAGE levels elevated immediately after cardiac surgery, and the range of elevation was associated with the morbidity of postoperative respiratory failure. Early postoperative sRAGE levels appear to be linked to cardiopulmonary bypass, and may have predictive performance for postoperative respiratory failure; however, large-scale validation studies are needed.

Postoperative respiratory failure in children with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals: a pilot study

OBJECTIVE

Children with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals (TOF/PA/MAPCAs), who undergo unifocalization surgery are at risk for prolonged postoperative respiratory failure. We sought to identify risk factors that are associated with prolonged mechanical ventilation in this population.

DESIGN

We collected preoperative and operative data from medical records and postoperative data prospectively. Mechanical ventilation beyond postoperative day 5, which was greater than the 50th percentile for the subjects enrolled, was considered prolonged. Risk factors were analyzed using multiple logistic regression, independent samples t test, Fisher's exact test, and Kruskal-Wallis test. Enrollment occurred over a 20-month period between May 2009 and January 2011.

SETTING

Lucile Packard Children's Hospital (Palo Alto, CA).

PATIENTS

All patients with TOF/PA/MAPCAs presenting for unifocalization or pulmonary artery revision procedures were eligible, including those with additional structural cardiac abnormalities requiring surgical intervention. We excluded patients with single-ventricle cardiac anatomy and preoperative respiratory failure or infection.

MEASUREMENTS AND MAIN RESULTS

We enrolled 35 consecutive patients undergoing 37 procedures over the study period. One patient was excluded for single-ventricle anatomy. There were 12 cases (32%) of prolonged mechanical ventilation. Delayed sternal closure was the only risk factor associated with prolonged mechanical ventilation (p = 0.01). Age, weight, cardiopulmonary bypass time, 22q11 microdeletion, postoperative fluid balance, bronchospasm, and nonrespiratory infection were not significantly associated with prolonged mechanical ventilation. Respiratory complications occurred in both groups, and patients with pneumonia were more likely to have a prolonged course (p = 0.03). There was no significant association between the type of surgery performed and duration of mechanical ventilation.

CONCLUSIONS

Prolonged postoperative respiratory failure in children undergoing surgery for TOF/PA/MAPCAs was independently associated with delayed sternal closure. Respiratory complications occur after unifocalization surgery, and pneumonia is associated with prolonged mechanical ventilation. Our pilot study suggests that clinical features common in this patient population, such as bronchospasm and 22q11 microdeletion, were not associated with more postoperative respiratory failure.

Risk factors for postoperative hypoxemia in patients undergoing Stanford A aortic dissection surgery

Background

The purpose of this study is to identify the risk factors for postoperative hypoxemia in patients with Stanford A aortic dissection surgery and their relation to clinical outcomes.

Methods

Clinical records of 186 patients with postoperative hypoxemia in Stanford A aortic dissection were analyzed retrospectively. The patients were divided into two groups by postoperative oxygen fraction (PaO2/FiO2):hypoxemia group (N=92) and non-hypoxemia group (N=94).

Results

We found that the incidence of postoperative hypoxemia was 49.5%. Statistical analysis by t-test and χ2 indicated that acute onset of the aortic dissection (p=0.000), preoperative oxygen fraction (PaO2/FiO2) ≤200 mmHg(p=0.000), body mass index (p=0.008), circulatory arrest (CA) time (p=0.000) and transfusion more than 3000 ml(p=0.000) were significantly associated with postoperative hypoxemia. Multiple logistic regression analysis showed that preoperative hypoxemia, CA time and transfusion more than 3000 ml were independently associated with postoperative hypoxemia in Stanford A aortic dissection.

Conclusion

Our results suggest that postoperative hypoxemia is a common complication in patients treated by Stanford A aortic dissection surgery. Preoperative oxygen fraction lower than 200 mmHg, longer CA time and transfusion more than 3000 ml are predictors of postoperative hypoxemia in Stanford A aortic dissection.