Preoperative pulmonary function and mortality after cardiac surgery

Scapulothoracic tenodesis using hamstring tendon graft for treatment of problematic scapula winging: A new surgical technique

Introduction

Winging of the scapula occurs due to dysfunction of its stabilising muscles, most commonly serratus anterior and/or trapezius, for example in facioscapulohumeral muscular dystrophy. Resultant loss of scapular control and abnormal kinematics can decrease shoulder function due to glenohumeral joint instability, loss of range of motion and pain. Previously described treatment for cases resistant to physiotherapy includes scapulothoracic arthrodesis which involves risk of non-union and metalwork failure, as well as reduced respiratory function due to immobilisation of a segment of the adjacent chest wall.

Technique

We present a novel surgical approach to the management of problematic scapular winging by using hamstring graft to achieve a scapulothoracic tenodesis.

Discussion

We believe this technique provides an adequately stable scapula for improved shoulder movement and function, a sufficiently mobile chest wall for improved lung function and avoidance of complications specifically associated with arthrodesis.

Pre-Habilitation of Cardiac Surgical Patients, Part 2: Frailty, Malnutrition, Respiratory disease, Alcohol/Smoking cessation and Depression

The concept of "pre-habilitation" comprises screening for and identification of pre-existing disorders followed by medical optimization. This is performed for many types of surgeries, but may have profound impacts on outcomes, particularly in cardiac surgery given the multiple comorbidities typically carried by these patients. Components of pre-habilitation include direct medical intervention by preoperative specialists as well as significant care coordination and shared decision-making. In this second part of a two-part review, the authors describe existing evidence to support the optimization of various preoperative problems and present a few institutional protocols utilized at out center for cardiac presurgical care. This second installment will focus on alcohol and smoking cessation and the management of frailty, malnutrition, respiratory disease, and depression.

Influence of reduced diffusing capacity and FEV1 on outcome after cardiac surgery

BACKGROUND

Impaired lung function is a well-known risk factor in cardiac surgery patients and reduced forced expiratory volume in 1 second (FEV₁ ) is associated with increased mortality. However, there is limited knowledge regarding the influence of impaired diffusing capacity of the lungs for carbon monoxide (DLCO) in unselected cardiac surgery patients. The aim of this study was to investigate the association of impaired DLCO and/or reduced FEV₁ on post-operative mortality and morbidity in cardiac surgery patients.

METHODS

In a prospective cohort study, 390 patients scheduled for elective cardiac surgery underwent preoperative lung function test including spirometry and DLCO measurements. We defined reduced FEV₁ as FEV₁ below lower limit of normal (LLN) and impaired DLCO as DLCO <60% of predicted.

RESULTS

Mortality within 1 year (90-570 days) was significantly higher in patients with impaired DLCO (12% vs 3%, P = .010) and with reduced FEV₁ (9% vs 3%, P = .028). Mortality was higher in patients with impaired DLCO both in the presence and absence of FEV₁  < LLN. In multivariate analysis, only impaired DLCO [OR: 3.3, 95% confidence interval (CI) 1.4-7.5; P = .005] and age (OR: 1.1 per year, 95% CI 1.0-1.2; P = .001) were independent predictors of the combined outcome of mortality and prolonged intensive care unit (ICU) stay. Impaired DLCO was also associated with post-operative respiratory complications.

CONCLUSION

In patients undergoing elective cardiac surgery, preoperative impaired FEV₁ and DLCO were associated with increased mortality and morbidity. In multivariate analysis, only DLCO and age were independent predictors of a combined outcome of mortality and prolonged ICU stay.

Pulmonary Function Testing Pre-heart Transplant Predicts Posttransplant Survival

Supplemental Digital Content is available in the text.

Although pulmonary function testing (PFT) is typically performed for heart transplant evaluation, the prognostic utility of PFTs after transplantation is unknown. We evaluated whether PFT parameters were correlated with outcomes following heart transplantation.

Healthcare-Associated Infections in a Cardiac Surgery Service in Brazil

Objectives

The study aimed to determine the incidence of healthcare-associated infections (HAI) and their sites in a cardiac surgery service, as well as to determine if gender and age were risk factors for infection and to quantify mortality and increase in the hospital length of stay (LOS) due to HAI.

Methods

Medical records of patients who underwent cardiac surgery from January 2012 to January 2018 were retrospectively analyzed. Data on age, gender, mortality, occurrence of HAI during hospitalization, and LOS were collected. Continuous variables were analyzed using Student's t-test, while categorical variables were compared using Fisher's exact test or chi-square test.

Results

Among the 195 patients available, the HAI rate in our service was 22.6%, with female gender being a risk factor for infections (odds ratio [OR]=2.23; P=0.015). Age was also a significant risk factor for infections, with a difference in the mean age between the group with and without infection (P=0.02). The occurrence of an infectious process increased the LOS in 14 days (P<0.001) and resulted in higher mortality rates (P=0.112). A patient who has HAI was approximately 19 times more likely to remain hospitalized for more than nine days (P<0.001).

Conclusion

Age and gender were risk factors for the development of HAI and the occurrence of an infectious process during hospitalization significantly increases the LOS. These findings may guide future actions aimed at reducing the impact of HAI on the health system.

Postoperative Delirium in Patients with Chronic Obstructive Pulmonary Disease after Coronary Artery Bypass Grafting

Background and Objectives: The incidence of postoperative delirium (POD) in patients with chronic obstructive pulmonary disease (COPD) is unclear. It seems that postoperative respiratory problems that may occur in COPD patients, including prolonged mechanical ventilation or respiratory-tract infections, may contribute to the development of delirium. The aim of the study was to identify a relationship between COPD and the occurrence of delirium after cardiac surgery and the impact of these combined disorders on postoperative mortality. Materials and Methods: We performed an analysis of data collected from 4151 patients undergoing isolated coronary artery bypass grafting (CABG) in a tertiary cardiac-surgery center between 2012 and 2018. We included patients with a clinical diagnosis of COPD according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. The primary endpoint was postoperative delirium; Confusion Assessment Method in the Intensive Care Unit (CAM-ICU) was used for delirium assessment. Results: Final analysis included 283 patients with COPD, out of which 65 (22.97%) were diagnosed with POD. Delirious COPD patients had longer intubation time (p = 0.007), more often required reintubation (p = 0.019), had significantly higher levels of C-reactive protein (CRP) three days after surgery (p = 0.009) and were more often diagnosed with pneumonia (p < 0.001). The CRP rise on day three correlated positively with the occurrence of postoperative pneumonia (r = 0.335, p = 0.005). The probability of survival after CABG was significantly lower in COPD patients with delirium (p < 0.001). Conclusions: The results of this study confirmed the relationship between chronic obstructive pulmonary disease and the incidence of delirium after cardiac surgery. The probability of survival in COPD patients undergoing CABG who developed postoperative delirium was significantly decreased.

Preoperative laboratory testing: Implications of "Choosing Wisely" guidelines

Preoperative laboratory testing is often necessary and can be invaluable for diagnosis, assessment, and treatment. However, performing routine laboratory tests for patients who are considered otherwise healthy is not usually beneficial and is costly. It is estimated that $18 billion (U.S.) is spent annually on preoperative testing, although how much is wasteful remains unknown. Ideally, a targeted and comprehensive patient history and physical exam should largely determine whether preprocedure laboratory studies should be obtained. Healthcare providers, primarily anesthesiologists, should remain cost-conscious when ordering specific laboratory or imaging tests prior to surgery based on available literature. We review the overall evidence and key points from the Choosing Wisely guidelines, the identification of potential wasteful practices, possible harms of testing, and key clinical findings associated with preoperative laboratory testing.

Screening for comorbidities in COPD

Due to growing recognition of comorbidities, COPD is no longer considered a disease affecting only the respiratory system. Its management now entails the early diagnosis and treatment of comorbidities. However, although many studies have examined the impact of comorbidities on the evolution of COPD and patients' quality of life, very few have explored the means to systematically identify and manage them. The aims of this article are to summarise the state of current knowledge about comorbidities associated with COPD and to propose a possible screening protocol in the outpatient setting, emphasising the areas needing further research.

Preoperative pulmonary function in all comers for cardiac surgery predicts mortality†

OBJECTIVES

Although reduced lung function and chronic obstructive pulmonary disease (COPD) is associated with higher risk of death following cardiac surgery, preoperative spirometry is not performed routinely. The aim of this study was to investigate the relationship between preoperative lung function and postoperative complications in all comers for cardiac surgery irrespective of smoking or COPD history.

METHODS

Preoperative spirometry was performed in elective adult cardiac surgery patients. Airflow obstruction was defined as the ratio of forced expiratory volume in 1 s (FEV1)/forced vital capacity ratio below the lower limit of normal (LLN) and reduced forced ventilatory capacity defined as FEV1 <LLN.

RESULTS

A history of COPD was reported by 132 (19%) patients; however, only 74 (56%) had spirometry-verified airflow obstruction. Conversely, 64 (12%) of the 551 patients not reporting a history of COPD had spirometry-verified airflow obstruction. The probability of death was significantly higher in patients with airflow obstruction (8.8% vs 4.5%, P = 0.04) and in patients with a FEV1 <LLN (8.7% vs 3.7%, P = 0.007). In the multivariate analysis were age [hazard ratio (HR) 1.6, 95% confidence interval (CI) 1.0-2.5; P = 0.04], prolonged cardiopulmonary bypass time (HR 1.2, 95% CI 1.02-1.3; P = 0.03), reduced kidney function (HR 2.5, 95% CI 1.2-5.6; P = 0.02) and FEV1 <LLN (HR 2.4, 95% CI 1.1-5.2; P = 0.03) all independently associated with an increased risk of death.

CONCLUSIONS

Preoperative spirometry reclassified 18% of the patients. A reduced FEV1 independently doubled the risk of death. Inclusion of preoperative spirometry in routine screening of cardiac surgical patients may improve risk prediction and identify high-risk patients.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01614951 (ClinicalTrials.gov).

Prolonged use of noninvasive positive pressure ventilation after extubation among patients in the intensive care unit following cardiac surgery: The predictors and its impact on patient outcome

This retrospective, observational cohort study aimed to determine the independent risk factors and impact of prolonged non-invasive positive pressure ventilation (NIPPV) after extubation among patients in the intensive care unit following cardiac surgery. Patients who received prophylactic NIPPV after extubation were categorized into prolonged (NIPPV duration >3 days, n = 83) and non-prolonged groups (NIPPV duration ≤3 days, n = 105). The perioperative characteristics and hospital outcomes were recorded. The multivariate analyses identified the preoperative residual volume/total lung capacity (RV/TLC) ratio (adjusted odds ratio [AOR]: 1.10; 95% CI:1.01–1.19, p = 0.022) and postoperative acute kidney injury (AKI) with Kidney Disease Improving Global Outcomes (KDIGO) stage 2–3, 48 h after surgery (AOR: 3.87; 95% CI:1.21–12.37, p = 0.023) as independent predictors of prolonged NIPPV. Patients with both RV/TLC ratio > 46.5% and KDIGO stage 2–3 showed a highly increased risk of prolonged NIPPV (HR 27.17, p = 0.010), which was in turn associated with higher risk of postoperative complications and prolonged ICU and hospital stays. Preoperative RV/TLC ratio and postoperative AKI could identify patients at higher risk for prolonged NIPPV associated with poor outcomes. These findings may allow early recognition of patients who are at a higher risk for prolonged NIPPV, and help refine the perioperative management and critical care.

Chronic hypoxia–induced Cirbp hypermethylation attenuates hypothermic cardioprotection via down-regulation of ubiquinone biosynthesis

Therapeutic hypothermia is commonly used during cardiopulmonary bypass (CPB) to protect the heart against myocardial injury in cardiac surgery. Patients who suffer from chronic hypoxia (CH), such as those with certain heart or lung conditions, are at high risk of severe myocardial injury after cardiac surgery, but the underlying mechanisms are unknown. This study tested whether CH attenuates hypothermic cardioprotection during CPB. Using a rat model of CPB, we found that hypothermic cardioprotection was impaired in CH rats but was preserved in normoxic rats. Cardiac proteomes showed that cold-inducible RNA binding protein (CIRBP) was significantly (P = 0.03) decreased in CH rats during CPB. Methylation analysis of neonatal rat cardiomyocytes under CH and myocardium specimens from patients with CH showed that CH induced hypermethylation of the Cirbp promoter region, resulting in its depression and failure to respond to cold stress. Cirbp-knockout rats showed attenuated hypothermic cardioprotection, whereas Cirbp-transgenic rats showed an enhanced response. Proteomics analysis revealed that the cardiac ubiquinone biosynthesis pathway was down-regulated during CPB in Cirbp-knockout rats, resulting in a significantly (P = 0.01) decreased concentration of ubiquinone (CoQ10). Consequently, cardiac oxidative stress was aggravated and adenosine 5′-triphosphate production was impaired, leading to increased myocardial injury during CPB. CoQ10-supplemented cardioplegic solution improved cardioprotection in rats exposed to CH, but its effect was limited in normoxic rats. Our study suggests that an individualized cardioprotection strategy should be used to fully compensate for the consequences of epigenetic modification of Cirbp in patients with CH who require therapeutic hypothermia.

Lung-diffusing capacity for carbon monoxide predicts early complications after cardiac surgery

PURPOSE

Preoperative pulmonary dysfunction has been associated with increased operative mortality and morbidity after cardiac surgery. This study aimed to determine whether values for the diffusing capacity of the lung for carbon monoxide (DL_CO) could predict postoperative complications after cardiac surgery.

METHODS

This study included 408 consecutive patients who underwent cardiac surgery between June 2008 and December 2015. DL_CO was routinely determined in all patients. A reduced DL_CO was clinically defined as %DL_CO < 70%. %DL_CO was calculated as DL_CO divided by the predicted DL_CO. The association between %DL_CO and in-hospital mortality was assessed, and independent predictors of complications were identified by a logistic regression analysis.

RESULTS

Among the 408 patients, 338 and 70 had %DL_CO values of ≥ 70% and < 70%, respectively. Complications were associated with in-hospital mortality (P < 0.001), but not %DL_CO (P = 0.275). A multivariate logistic regression analysis with propensity score matching identified reduced DL_CO as an independent predictor of complications (OR, 3.270; 95%CI, 1.356-7.882; P = 0.008).

CONCLUSIONS

%DL_CO is a powerful predictor of postoperative complications. The preoperative DL_CO values might provide information that can be used to accurately predict the prognosis after cardiac surgery.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000029985.

Protective effect of remote ischemic pre-conditioning on patients undergoing cardiac bypass valve replacement surgery: A randomized controlled trial

Remote ischemic pre-conditioning (RIPC) may have a protective effect on myocardial injury associated with cardiac bypass surgery (CPB). The objective of the present study was to investigate the effect of RIPC on ischemia/reperfusion (I/R) injury and to assess the underlying mechanisms. A total of 241 patients who underwent valve replacement were randomly assigned to receive either RIPC (n=121) or control group (n=120). The primary endpoint was peri-operative myocardial injury (PMI), which was determined by serum Highly sensitive cardiac troponin T (hsTnT). The secondary endpoint was the blood gas indexes, acute lung injury and length of intensive care unit stay, length of hospital stay and major adverse cardiovascular events. The results indicated that in comparison with control group, RIPC treatment reduced the levels of hsTnT at 6 and 24 h post-CPB (P<0.001), as well as the alveolar-arterial oxygen pressure difference and respiratory index after CPB. Furthermore, RIPC reduced the incidence of acute lung injury by 15.3% (54.1% in the control group vs. 41.3% in the RIPC group, P=0.053). It was indicated that RIPC provided myocardial and pulmonary protection during CPB. In addition, the length of the intensive care unit and hospital stay was reduced by RIPC. Mechanistic investigation revealed a reduced content of soluble intercellular adhesion molecule-1, endothelin-1 and malondialdehyde, as well as elevated levels of nitric oxide in the RIPC group compared with those in the control group. This indicated that RIPC protected against I/R injury associated with CPB through reducing the inflammatory response and oxidative damage, as well as improving pulmonary vascular tension. In conclusion, RIPC reduced myocardial and pulmonary injury associated with CPB. This protective effect may be associated with the inhibition of the inflammatory response and oxidative injury. The present study proved the efficiency of this approach in reducing ischemia/reperfusion injury associated with cardiac surgery. Clinical trial registry no. ChiCTR1800015393.

Prediction of Post Operative Complication in Patients with Valvular Heart Surgery Based on O2 Challenge Test and A-A Gradient

Patients with valvular heart diseases may have more physiological lung derangements and therefore at current study we studied correlation of O2 challenge, A-AG tests and spirometry values of patients who underwent valve surgery on post op respiratory complications. Method: 180 adult patients undergoing non-emergency cardiac valvular surgery were studied. On operating room all patients had arterial blood gas profile (ABG) at room air, 20 minutes after putting on ventilator with 100% O2, and pump oxygenator. Pulmonary function tests, alveolar Oxygen Pressure, mean Arterial pressure of carbon dioxide and alveolar -arterial gradients measured. Results: FEV1, FVC and FEV1/FVC%, pressure of arterial Blood Gasses (O2 and CO2) with fraction of inspired oxygen of 100% and air (PO2-100 and PO2-air), were significantly different between patients with POPC and patients without POPC (p-value <0.05). Indeed PO2-100 and PO2-air were significantly lower in patients with POPC. A-AG100 (p-value: 0.02) and A -AG21 (p-value: 0.02) were significantly higher in patients with POPC in comparison with patients without POPC. The AUC of A-AG100 for predicting POPC was 0.59 (95% confidence interval (CI) 0.51-0.67). The optimal cut point of A-AG100 was 311 and showed evidence of high relatively sensitivity of 80% and a negative predictive value of 61%. Conclusion: Valvular heart surgery still has significant post op complication and mortality. There is significant correlation between A-AG100, A-AG21 percent, PaO2100, and FEV1/FVC with post op complications in these patients. We recommend measurement of these values in pre op evaluation of patient who need cardiac surgery.

Lung Protection Strategies during Cardiopulmonary Bypass Affect the Composition of Blood Electrolytes and Metabolites-A Randomized Controlled Trial

Cardiac surgery with cardiopulmonary bypass (CPB) causes an acute lung ischemia-reperfusion injury, which can develop to pulmonary dysfunction postoperatively. This sub-study of the Pulmonary Protection Trial aimed to elucidate changes in arterial blood gas analyses, inflammatory protein interleukin-6, and metabolites of 90 chronic obstructive pulmonary disease patients following two lung protective regimens of pulmonary artery perfusion with either hypothermic histidine-tryptophan-ketoglutarate (HTK) solution or normothermic oxygenated blood during CPB, compared to the standard CPB with no pulmonary perfusion. Blood was collected at six time points before, during, and up to 20 h post-CPB. Blood gas analysis, enzyme-linked immunosorbent assay, and nuclear magnetic resonance spectroscopy were used, and multivariate and univariate statistical analyses were performed. All patients had decreased gas exchange, augmented inflammation, and metabolite alteration during and after CPB. While no difference was observed between patients receiving oxygenated blood and standard CPB, patients receiving HTK solution had an excess of metabolites involved in energy production and detoxification of reactive oxygen species. Also, patients receiving HTK suffered a transient isotonic hyponatremia that resolved within 20 h post-CPB. Additional studies are needed to further elucidate how to diminish lung ischemia-reperfusion injury during CPB, and thereby, reduce the risk of developing severe postoperative pulmonary dysfunction.

The effect of high-flow nasal oxygen on hospital length of stay in cardiac surgical patients at high risk for respiratory complications: a randomised controlled trial

There has been increased interest in the prophylactic and therapeutic use of high‐flow nasal oxygen in patients with, or at risk of, non‐hypercapnic respiratory failure. There are no randomised trials examining the efficacy of high‐flow nasal oxygen in high‐risk cardiac surgical patients. We sought to determine whether routine administration of high‐flow nasal oxygen, compared with standard oxygen therapy, leads to reduced hospital length of stay after cardiac surgery in patients with pre‐existing respiratory disease at high risk for postoperative pulmonary complications. Adult patients with pre‐existing respiratory disease undergoing elective cardiac surgery were randomly allocated to receive high‐flow nasal oxygen (n = 51) or standard oxygen therapy (n = 49). The primary outcome was hospital length of stay and all analyses were carried out on an intention‐to‐treat basis. Median (IQR [range]) hospital length of stay was 7 (6–9 [4–30]) days in the high‐flow nasal oxygen group and 9 (7–16 [4–120]) days in the standard oxygen group (p=0.012). Geometric mean hospital length of stay was 29% lower in the high‐flow nasal group (95%CI 11–44%, p = 0.004). High‐flow nasal oxygen was also associated with fewer intensive care unit re‐admissions (1/49 vs. 7/45; p = 0.026). When compared with standard care, prophylactic postoperative high‐flow nasal oxygen reduced hospital length of stay and intensive care unit re‐admission. This is the first randomised controlled trial examining the effect of prophylactic high‐flow nasal oxygen use on patient‐centred outcomes in cardiac surgical patients at high risk for postoperative respiratory complications.

Chronic obstructive pulmonary disease severity influences outcomes after off-pump coronary artery bypass

OBJECTIVE

To analyze the impact and severity of chronic obstructive pulmonary disease (COPD) on pulmonary function and postoperative clinical outcome based on the Global Initiative for Obstructive Lung Disease criteria in patients undergoing off-pump coronary artery bypass grafting (CABG).

METHODS

Patients were allocated into 3 groups according to presence and severity of COPD: no or mild COPD (n = 144); moderate COPD (n = 77); and severe COPD (n = 30). Spirometry values were obtained preoperatively and on postoperative days (PODs) 2 and 5. The incidences of pneumonia and reintubation, time of mechanical ventilation, and length of postoperative hospital stay were recorded.

RESULTS

Significant impairment in pulmonary function was observed in all groups on PODs 2 and 5 (P < .001). However, postoperative pulmonary dysfunction was significantly higher in the moderate and severe COPD groups compared with the no or mild COPD group (P < .05). On multivariable analysis, severe COPD was associated with an elevated risk for composite outcomes (odds ratio, 1.37; 95% confidence interval, 1.20-1.57; P < .001). A preoperative forced expiratory volume in 1 second (FEV₁) <50% of the predicted value was associated with poor outcome. A significant negative correlation was found between FEV₁ at POD 5 and postoperative length of stay (r = -0.5; P < .001).

CONCLUSIONS

More severe COPD was associated with greater impairment in pulmonary function and worse clinical outcomes after off-pump CABG surgery. A preoperative FEV₁ <50% of predicted value appears to be an important predictor of postoperative complications.

Pulmonary artery perfusion versus no perfusion during cardiopulmonary bypass for open heart surgery in adults

BACKGROUND

Available evidence has been inconclusive on whether pulmonary artery perfusion during cardiopulmonary bypass (CPB) is associated with decreased or increased mortality, pulmonary events, and serious adverse events (SAEs) after open heart surgery. To our knowledge, no previous systematic reviews have included meta-analyses of these interventions.

OBJECTIVES

To assess the benefits and harms of single-shot or continuous pulmonary artery perfusion with blood (oxygenated or deoxygenated) or a preservation solution compared with no perfusion during cardiopulmonary bypass (CPB) in terms of mortality, pulmonary events, serious adverse events (SAEs), and increased inflammatory markers for adult surgical patients.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Science Citation Index Expanded, and advanced Google for relevant studies. We handsearched retrieved study reports and scanned citations of included studies and relevant reviews to ensure that no relevant trials were missed. We searched for ongoing trials and unpublished trials in the World Health Organization International Clinical Trials Registry Platform (ICTRP) and at clinicaltrials.gov (4 July 2017). We contacted medicinal firms producing preservation solutions to retrieve additional studies conducted to examine relevant interventions.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared pulmonary artery perfusion versus no perfusion during CPB in adult patients (≧ 18 years).

DATA COLLECTION AND ANALYSIS

Two independent review authors extracted data, conducted fixed-effect and random-effects meta-analyses, and calculated risk ratios (RRs) or odds ratios (ORs) for dichotomous outcomes. For continuous data, we have presented mean differences (MDs) and 95% confidence intervals (CIs) as estimates of the intervention effect. To minimize the risk of systematic error, we assessed risk of bias of included trials. To reduce the risk of random errors caused by sparse data and repetitive updating of cumulative meta-analyses, we applied Trial Sequential Analyses (TSAs). We used GRADE principles to assess the quality of evidence.

MAIN RESULTS

We included in this review four RCTs (210 participants) reporting relevant outcomes. Investigators randomly assigned participants to pulmonary artery perfusion with blood versus no perfusion during CPB. Only one trial included the pulmonary artery perfusion intervention with a preservation solution; therefore we did not perform meta-analysis. Likewise, only one trial reported patient-specific data for the outcome "pulmonary events"; therefore we have provided no results from meta-analysis. Instead, review authors added two explorative secondary outcomes for this version of the review: the ratio of partial pressure of oxygen in arterial blood (PaO₂) to fraction of inspired oxygen (FiO₂); and intubation time. Last, review authors found no comparable data for the secondary outcome inflammatory markers.The effect of pulmonary artery perfusion on all-cause mortality was uncertain (Peto OR 1.78, 95% CI 0.43 to 7.40; TSA adjusted CI 0.01 to 493; 4 studies, 210 participants; GRADE: very low quality). Sensitivity analysis of one trial with overall low risk of bias (except for blinding of personnel during the surgical procedure) yielded no evidence of a difference for mortality (Peto OR 1.65, 95% CI 0.27 to 10.15; 1 study, 60 participants). The TSA calculated required information size was not reached and the futility boundaries did not cross; thus this analysis cannot refute a 100% increase in mortality.The effect of pulmonary artery perfusion with blood on SAEs was likewise uncertain (RR 1.12, 95% CI 0.66 to 1.89; 3 studies, 180 participants; GRADE: very low quality). Data show an association between pulmonary artery perfusion with blood during CPB and a higher postoperative PaO₂/FiO₂ ratio (MD 27.80, 95% CI 5.67 to 49.93; 3 studies, 119 participants; TSA adjusted CI 5.67 to 49.93; GRADE: very low quality), although TSA could not confirm or refute a 10% increase in the PaO₂/FiO₂ ratio, as the required information size was not reached.

AUTHORS' CONCLUSIONS

The effects of pulmonary artery perfusion with blood during cardiopulmonary bypass (CPB) are uncertain owing to the small numbers of participants included in meta-analyses. Risks of death and serious adverse events may be higher with pulmonary artery perfusion with blood during CPB, and robust evidence for any beneficial effects is lacking. Future randomized controlled trials (RCTs) should provide long-term follow-up and patient stratification by preoperative lung function and other documented risk factors for mortality. One study that is awaiting classification (epub abstract with preliminary results) may change the results of this review when full study details have been published.

Analysis of the influence of respiratory disorders observed in preoperative spirometry on the dynamics of early inflammatory response in patients undergoing isolated coronary artery bypass grafting

Background

Preoperative spirometry provides measurable information about the occurrence of respiratory disorders. The aim of this study was to assess the association between preoperative spirometry abnormalities and the intensification of early inflammatory responses in patients following coronary artery bypass graft in extracorporeal circulation.

Material and methods

The study involved 810 patients (625 men and 185 women) aged 65.4±7.9 years who were awaiting isolated coronary artery bypass surgery. On the basis of spirometry performed on the day of admittance to the hospital, the patients were divided into three groups. Patients without respiratory problems constituted 78.8% of the entire group. Restricted breathing was revealed by spirometry in 14.9% and obstructive breathing in 6.3% of patients.

Results

Inter-group analysis showed statistically significant differences in C-reactive protein (CRP) between patients with restrictive spirometry abnormalities and patients without any pulmonary dysfunction. CRP concentrations differed before surgery (P=0.006) and on the second (P<0.001), fourth (P=0.005) and sixth days after surgery (P=0.029). There was a negative correlation between CRP levels and FEV₁.

Conclusion

In our study, the most common pulmonary disorders in the coronary artery bypass graft patients were restrictive. Patients with abnormal spirometry results from restrictive respiratory disorders have an elevated level of generalized inflammatory response both before and after the isolated coronary artery bypass surgery. Therefore, this group of patients should be given special postoperative monitoring and, in particular, intensive respiratory rehabilitation immediately after reconstitution.

Prevalence and Implications of Abnormal Respiratory Patterns in Cardiac Surgery: A Prospective Cohort Study

OBJECTIVE

To investigate the prevalence and impact of abnormal respiratory patterns in cardiac surgery patients.

DESIGN

Prospective cohort study.

SETTING

Tertiary hospital.

PARTICIPANTS

Patients scheduled for elective coronary artery bypass graft surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Pulmonary function tests were performed in 454 patients before surgery. Abnormal respiratory patterns were defined as follows: obstructive (forced expiratory volume in 1 s [FEV₁]/forced vital capacity [FVC]<0.70), restrictive (FEV₁/FVC≥0.70 and FVC<80% of predicted), and mixed (FEV₁/FVC<0.70 and both FEV₁ and FVC<80% of predicted). Of the 31 patients with a history of chronic obstructive pulmonary disease, no abnormal respiratory pattern was confirmed in 5. Of the 423 patients without a history of lung disease, the authors newly identified 57 obstructive, 46 restrictive, and 4 mixed patterns. Therefore, lung disease was reclassified in 24.7% of cases. Independent predictors of obstructive pattern were age, male sex, history of smoking, and chronic obstructive pulmonary disease. Obstructive lung disease was associated with 16 hours or longer ventilation. A reduced FEV₁ was associated with a likelihood of atrial fibrillation (1-L decrement, odds ratio: 1.38, 95% confidence interval: 1.01-to-1.90, p = 0.04) and hospitalization time (regression coefficient: 1.23, 95% confidence interval: 0.54-to-1.91, p<0.001).

CONCLUSIONS

Abnormal respiratory patterns are common and often underdiagnosed in the cardiac surgery setting. Pulmonary function tests help reveal patients at risk of complications and may provide an opportunity for intervention.

Pulmonary artery perfusion versus no pulmonary perfusion during cardiopulmonary bypass in patients with COPD: a randomised clinical trial

Introduction

Absence of pulmonary perfusion during cardiopulmonary bypass (CPB) may be associated with reduced postoperative oxygenation. Effects of active pulmonary artery perfusion were explored in patients with chronic obstructive pulmonary disease (COPD) undergoing cardiac surgery.

Methods

90 patients were randomised to receive pulmonary artery perfusion during CPB with either oxygenated blood (n=30) or histidine-tryptophan-ketoglutarate (HTK) solution (n=29) compared with no pulmonary perfusion (n=31). The coprimary outcomes were the inverse oxygenation index compared at 21 hours after starting CPB and longitudinally in a mixed-effects model (MEM). Secondary outcomes were tracheal intubation time, serious adverse events, mortality, days alive outside the intensive care unit (ICU) and outside the hospital.

Results

21 hours after starting CPB patients receiving pulmonary artery perfusion with normothermic oxygenated blood had a higher oxygenation index compared with no pulmonary perfusion (mean difference (MD) 0.94; 95% CI 0.05 to 1.83; p=0.04). The blood group had also a higher oxygenation index both longitudinally (MEM, p=0.009) and at 21 hours (MD 0.99; CI 0.29 to 1.69; p=0.007) compared with the HTK group. The latest result corresponds to a difference in the arterial partial pressure of oxygen of 23 mm Hg with a median fraction of inspired oxygen of 0.32. Yet the blood or HTK groups did not demonstrate a longitudinally higher oxygenation index compared with no pulmonary perfusion (MEM, p=0.57 and 0.17). Similarly, at 21 hours there was no difference in the oxygenation index between the HTK group and those no pulmonary perfusion (MD 0.06; 95% CI −0.73 to 0.86; p=0.87). There were no statistical significant differences between the groups for the secondary outcomes.

Discussion

Pulmonary artery perfusion with normothermic oxygenated blood during cardiopulmonary bypass appears to improve postoperative oxygenation in patients with COPD undergoing cardiac surgery. Pulmonary artery perfusion with hypothermic HTK solution does not seem to improve postoperative oxygenation.

Trial registration number

NCT01614951; Pre-results.

Arterial Blood Gas Analysis in Chronic Obstructive Pulmonary Disease Patients Undergoing Coronary Artery Bypass Surgery

OBJECTIVES

We aimed to investigate the impact of arterial blood gas (ABG) on morbidity and mortality in chronic obstructive pulmonary disease (COPD) patients undergoing CABG surgery.

MATERIAL AND METHODS

The records for 75 COPD patients who underwent elective CABG surgery our institution clinic between November 2008 to 2011 and had a forced expiratory volume in 1 second (FEV₁)/forced vital capacity (FVC) ≤ 70% value in the pulmonary function tests (PFT) performed prior to the surgery were evaluated retrospectively. COPD patients were divided into two groups; Group 1; FEV₁ ≥ 60% and Group 2; FEV₁ ≤ 59%. Groups were compared for mortality and adverse events after identification of other preoperative and postoperative factors that could affect mortality and adverse events. An ABG was obtained immediately before and 3 to 6 hours after surgery to study the predictive value of ABG in seperate COPD groups.

RESULTS

There were no significant differences in patients with high partial pressure carbondioxide (PaCO₂) preoperative values compared to patients with normal values. Also there were no significant differences in patients with lower partial pressure of oxygen (PaO₂) preoperative values compared to patients with normal values in terms of mortality. Postoperative myocardial infarction (MI) was significantly higher in patients with low PaO₂ values (p< 0.05).

CONCLUSION

In conclusion, in our study, there could not be found a relation between the degree of preoperative obstruction and mortality for COPD patients who underwent CABG surgery. ABG was not found useful for predicting mortality in COPD patients undergoing CABG surgery, but could be useful to predict postoperative MI in patients with COPD.

Do preoperative pulmonary function indices predict morbidity after coronary artery bypass surgery?

Context:

The reported prevalence of chronic obstructive pulmonary disease (COPD) varies among different groups of cardiac surgical patients. Moreover, the prognostic value of preoperative COPD in outcome prediction is controversial.

Aims:

The present study assessed the morbidity in the different levels of COPD severity and the role of pulmonary function indices in predicting morbidity in patients undergoing coronary artery bypass graft (CABG).

Settings and Design:

Patients who were candidates for isolated CABG with cardiopulmonary bypass who were recruited for Tehran Heart Center-Coronary Outcome Measurement Study.

Methods:

Based on spirometry findings, diagnosis of COPD was considered based on Global Initiative for Chronic Obstructive Lung Disease category as forced expiratory volume in 1 s [FEV1]/forced vital capacity <0.7 (absolute value, not the percentage of the predicted). Society of Thoracic Surgeons (STS) definition was used for determining COPD severity and the patients were divided into three groups: Control group (FEV1 >75% predicted), mild (FEV1 60–75% predicted), moderate (FEV1 50–59% predicted), severe (FEV1<50% predicted). The preoperative pulmonary function indices were assessed as predictors, and postoperative morbidity was considered the surgical outcome.

Results:

This study included 566 consecutive patients. Patients with and without COPD were similar regarding baseline characteristics and clinical data. Hypertension, recent myocardial infarction, and low ejection fraction were higher in patients with different degrees of COPD than the control group while male gender was more frequent in control patients than the others. Restrictive lung disease and current cigarette smoking did not have any significant impact on postoperative complications. We found a borderline P = 0.057 with respect to respiratory failure among different patients of COPD severity so that 14.1% patients in control group, 23.5% in mild, 23.4% in moderate, and 21.9% in severe COPD categories developed respiratory failure after CABG surgery.

Conclusion:

Among post-CABG complications, patients with different levels of COPD based on STS definition, more frequently developed respiratory failure. This finding may imply the prognostic value of preoperative pulmonary function test for determining COPD severity and postoperative morbidities.

Preoperative pulmonary function tests predict mortality after surgical or transcatheter aortic valve replacement

OBJECTIVES

To determine the role of preoperative pulmonary function tests (PFTs) in patients with aortic stenosis (AS) evaluated for aortic valve replacement (AVR), and to evaluate the association between lung disease and mortality in specific subgroups.

METHODS

Between 2008 and 2013, 535 patients with preoperative PFTs underwent AVR (transcatheter AVR [TAVR], n = 246; surgical AVR [SAVR], n = 289). The severity of lung disease determined by the Society of Thoracic Surgeons (STS) definition was evaluated in those with and without a clinical suspicion for lung disease (smoking, inhaled steroids/bronchodilators, or home oxygen). The association between lung disease and 1-year mortality was evaluated.

RESULTS

Of the 186 patients (35%) without suspected lung disease, 39 (21%) had moderate/severe lung disease by PFT analysis. Among all patients, 1-year mortality was 12% in those with no lung disease, 17% in those with no mild lung disease, 22% in those with moderate lung disease, and 31% in those with severe lung disease (P < .001, log-rank test). After adjustment, moderate/severe lung disease was associated with increased 1-year mortality (adjusted hazard ratio, 2.07; 95% confidence interval, 1.30-3.29; P = .002); this association was not altered by smoking history, suspicion of lung disease, New York Heart Association class, or AVR type (interaction P value nonsignificant for all).

CONCLUSIONS

In patients with AS evaluated for AVR, the STS risk score is significantly influenced by the severity of lung disease, which is determined predominantly by PFT results. Even when lung disease is not suspected, PFTs are abnormal in many patients undergoing AVR. Moderate/severe lung disease, diagnosed predominantly by PFTs, is an independent predictor of mortality after SAVR or TAVR. Collectively, these findings suggest that PFTs should be a routine part of the risk stratification of patients considered for AVR.

Acute hemodynamic decompensation during catheter ablation of scar-related ventricular tachycardia: incidence, predictors, and impact on mortality

BACKGROUND

The occurrence of periprocedural acute hemodynamic decompensation (AHD) in patients undergoing radiofrequency catheter ablation of scar-related ventricular tachycardia (VT) has not been previously investigated.

METHODS AND RESULTS

We identified univariate predictors of periprocedural AHD in 193 consecutive patients undergoing radiofrequency catheter ablation of scar-related VT. AHD was defined as persistent hypotension despite vasopressors and requiring mechanical support or procedure discontinuation. AHD occurred in 22 (11%) patients. Compared with the rest of the population, patients with AHD were older (68.5±10.7 versus 61.6±15.0 years; P=0.037); had a higher prevalence of diabetes mellitus (36% versus 18%; P=0.045), ischemic cardiomyopathy (86% versus 52%; P=0.002), chronic obstructive pulmonary disease (41% versus 13%; P=0.001), and VT storm (77% versus 43%; P=0.002); had more severe heart failure (New York Heart Association class III/IV: 55% versus 15%, P<0.001; left ventricular ejection fraction: 26±10% versus 36±16%, P=0.003); and more often received periprocedural general anesthesia (59% versus 29%; P=0.004). At 21±7 months follow-up, the mortality rate was higher in the AHD group compared with the rest of the population (50% versus 11%, log-rank P<0.001).

CONCLUSIONS

AHD occurs in 11% of patients undergoing radiofrequency catheter ablation of scar-related VT and is associated with increased risk of mortality over follow-up. AHD may be predicted by clinical factors, including advanced age, ischemic cardiomyopathy, more severe heart failure status (New York Heart Association class III/IV, lower ejection fraction), associated comorbidities (diabetes mellitus and chronic obstructive pulmonary disease), presentation with VT storm, and use of general anesthesia.

The association of chronic lung disease with early mortality and respiratory adverse events after aortic valve replacement

BACKGROUND

We studied the association between components of chronic lung disease (CLD) assessment and operative outcomes in patients undergoing aortic valve replacement (AVR) for aortic stenosis.

METHODS

From 2011 to 2012, 9,177 patients included in The Society of Thoracic Surgeons (STS) Cardiac Surgery Database underwent AVR for aortic stenosis with complete pulmonary function tests (PFT) and CLD data (31% of AVRs). We evaluated markers of CLD and their association with operative mortality, pulmonary morbidity, and length of hospital stay using multivariable logistic regression analysis.

RESULTS

In a selected population of AVR patients with PFTs, CLD was prevalent in 50% (mild, 25.6%; moderate, 13.2%; severe, 11.2%). Predicted forced expiratory volume in 1 second (FEV1) was obtained in all patients and diffusion capacity of the lung for carbon monoxide (DLCO), arterial oxygen tension (PaO2), and arterial carbon dioxide tension (PaCO2) in 31%. The STS predicted risk of operative mortality, mortality, pulmonary morbidity, and hospital stay increased with severity of CLD and with low FEV1, DLCO, and PaO2. Moderate and severe CLD were independently associated with operative mortality (odds ratio [OR] 2.88, 95% confidence interval [CI]: 2.0-4.5), pulmonary morbidity (OR 2.33, 95% CI: 1.93-2.8), and prolonged hospital stay (OR 2.73, 95% CI: 2.17-3.45). Low FEV1 was independently associated with pulmonary morbidity and prolonged hospital stay. Low PaO2 and DLCO were independently associated with a combined mortality and pulmonary morbidity endpoint.

CONCLUSIONS

CLD is associated with adverse operative outcomes in selected patients with aortic stenosis undergoing AVR. FEV1, DLCO, and PaO2 may add important information to current risk adjustment models beyond the broad CLD classification.

Assessing the risk of aortic valve replacement for severe aortic stenosis in the transcatheter valve era

Surgical aortic valve replacement had been the only definitive treatment of severe aortic stenosis before the availability of transcatheter valve technology. Historically, many patients with severe aortic stenosis had not been offered surgery, largely related to professional and patient perception regarding the risks of operation relative to anticipated benefits. Such patients have been labeled as "high risk" or "inoperable" with respect to their suitability for surgery. The availability of transcatheter aortic valve replacement affords a new treatment option for patients previously not felt to be optimal candidates for surgical valve replacement and allows for the opportunity to reexamine the methods for assessing operative risk in the context of more than 1 available treatment. Standardized risk assessment can be challenging because of both the imprecision of current risk scoring methods and the variability in ascertaining risk related to operator experience as well as local factors and practice patterns at treating facilities. Operative risk in actuality is not an absolute but represents a spectrum from very low to extreme, and the conventional labels of high risk and inoperable are incomplete with respect to their utility in clinical decision making. Moving forward, the emphasis should be on developing an individual assessment that takes into account procedure risk as well as long-term outcomes evaluated in a multidisciplinary fashion, and incorporating patient preferences and goals in a model of shared decision making.

Incidence and risk factors for impaired mobility in older cardiac surgery patients during the early postoperative period

AIM

Mobility issues in the early postoperative period result in poor functional outcomes and diminished quality of life for patients of advanced age. We determined the incidence of and risk factors for mobility issues in the early postoperative period in patients receiving open heart cardiac surgery.

METHODS

A retrospective chart review was carried out on 396 patients receiving open heart coronary artery bypass grafts (CABG), valve replacements and combination CABG-valve replacements in a tertiary care hospital. Data on demographics, comorbidities, laboratory values, medications, anesthesia and postoperative care were abstracted. Mobility issues were considered present if they were documented in the medical chart. All pre- and intraoperative variables were entered into logistic regression.

RESULTS

The mean age was 66.4 ± 11.9 years. In a subset of patients aged 75 years and older, the mean age was 79.8 ± 3.7 years. Mobility issues affected 36.9% of individuals from the total sample, and 47.6% of older patients. Increased age was a weak predictor in the total sample (OR 1.03), but was the only predictor in older adults (OR 1.1). The strongest predictors in the total sample were preoperative COPD (OR 2.7), congestive heart failure (CHF; OR 2.1), renal disease (OR 1.9), and pre-existing physical impairment (OR 1.8). Older patients with mobility issues were more likely to be discharged to acute care facilities, and had higher rates of mortality 3 years after surgery.

CONCLUSIONS

Over one-third of cardiac surgery patients experienced early postoperative mobility issues. Older patients and those with COPD, CHF, renal disease or pre-existing physical impairments might benefit from preoperative consultation with physical therapists.

Forced expiratory volume in one second predicts length of stay and in-hospital mortality in patients undergoing cardiac surgery: a retrospective cohort study

Objective

An aging population and increasing use of percutaneous therapies have resulted in older patients with more co-morbidity being referred for cardiac surgery. Objective measurements of physiological reserve and severity of co-morbid disease are required to improve risk stratification. We hypothesised that FEV₁ would predict mortality and length of stay following cardiac surgery.

Methods

We assessed clinical outcomes in 2,241 consecutive patients undergoing coronary artery bypass grafting and/or valve surgery from 2001 to 2007 in a regional cardiac centre. Generalized linear models of the association between FEV₁ and length of hospital stay and mortality were adjusted for age, sex, height, body mass index, socioeconomic status, smoking, cardiovascular risk factors, long-term use of bronchodilators or steroids for lung disease, and type and urgency of surgery. FEV₁ was compared to an established risk prediction model, the EuroSCORE.

Results

Spirometry was performed in 2,082 patients (93%) whose mean (SD) age was 67 (10) years. Median hospital stay was 3 days longer in patients in the lowest compared to the highest quintile for FEV₁, 1.35-fold higher (95% CI 1.20–1.52; p<0.001). The adjusted odds ratio for mortality was increased 2.11-fold (95% CI 1.45–3.08; p<0.001) per standard deviation decrement in FEV₁ (800 ml). FEV₁ improved discrimination of the EuroSCORE for mortality. Similar associations were found after excluding people with known pulmonary disease and/or airflow limitation on spirometry.

Conclusions

Reduced FEV₁ strongly predicted increased length of stay and in-hospital mortality following cardiac surgery. FEV₁ is a widely available measure of physiological health that may improve risk stratification of complex patients undergoing cardiac surgery and should be evaluated for inclusion in new prediction tools.

Pulmonary perfusion with oxygenated blood or custodiol HTK solution during cardiac surgery for postoperative pulmonary function in COPD patients: a trial protocol for the randomized, clinical, parallel group, assessor and data analyst blinded Pulmonary Protection Trial

Background

Five to thirty percent of patients undergoing cardiac surgery present with chronic obstructive pulmonary disease (COPD) and have a 2- to 10-fold higher 30-day mortality risk. Cardiopulmonary bypass (CPB) creates a whole body systemic inflammatory response syndrome (SIRS) that could impair pulmonary function. Impaired pulmonary function can, however, be attenuated by pulmonary perfusion with oxygenated blood or custodiol HTK (histidine-tryptophan-ketoglutarate) solution.

Methods/Design

The Pulmonary Protection Trial (PP-Trial) randomizes 90 patients undergoing CPB-dependent cardiac surgery to evaluate whether pulmonary perfusion with oxygenated blood or custodiol HTK solution reduces postoperative pulmonary dysfunction in COPD patients. Further, we aim for a non-randomized evaluation of postoperative pulmonary function after transcatheter aortic-valve implantation (TAVI). The primary outcome measure is the oxygenation index measured from anesthesia induction to the end of surgery and until 24 hours after anesthesia induction for a total of six evaluations.

Discussion

Patients with COPD may be impaired by hypoxemia and SIRS. Thus, prolonged recovery and even postoperative complications and death may be reflected by the degree of hypoxemia and SIRS. The limited sample size does not aim for confirmatory conclusions on mortality, cardiovascular complications or risk of pneumonia and sepsis, but the PP-Trial is considered an important feasibility trial paving the road for a multicenter confirmatory trial.

Trial registration

ClinicalTrials.gov: NCT01614951.

Variation of mortality after coronary artery bypass surgery in relation to hour, day and month of the procedure

BACKGROUND

Mortality and complications after percutaneous coronary intervention is higher when performed after regular duty hours due to challenging patient characteristics, inferior processes of care and limited resources. Since these challenges are also encountered during coronary artery bypass graft (CABG) surgery that is performed after regular work hours, we assessed whether hour and day of procedure influenced mortality after CABG.

METHODS

We studied 4,714 consecutive patients who underwent CABG at the Minneapolis Veterans Administration (VA) Medical Center between 1987 and 2009. We compared postoperative (30-day) mortality rates in relation to hour and day in which the operation was performed.

RESULTS

Operations performed on weekends and after 4 PM had higher risk patients (p < 0.0001) and were more likely to be emergent (p < 0.0001), require intra-aortic balloon pump support (p < 0.0001) and result in postoperative complications (p < 0.0001) compared to those at regular work hours. Mortality was significantly higher when CABG was performed on weekends compared to weekdays (9.4% versus 2.5%; odds ratio (OR) 4.1, 95% confidence interval (CI) 1.6 to 10.4, p = 0.003), and after 4 PM compared to between 7 AM-4 PM (6.2% versus 2.2%; OR 2.9, 95% CI 1 to 8, p = 0.049). In multivariable analysis, when adjusted for the urgency of the operation and the VA estimated mortality risk score, these associations were no longer statistically significant.

CONCLUSIONS

Mortality after CABG is higher when surgery is performed on the weekends and after 4 PM. These variations in mortality were related to higher patient risk, and urgency of the operation rather than external factors.