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(Chest. 2005;127:892-901.)
© 2005 American College of Chest Physicians

Pulmonary Outcomes of Off-Pump vs On-Pump Coronary Artery Bypass Surgery in a Randomized Trial*

Gerald W. Staton, MD, FCCP; Willis H. Williams, MD; Elizabeth M. Mahoney, ScD; Jeff Hu, MD; Haitao Chu, PhD; Peggy G. Duke, MD and John D. Puskas, MD

* From the Departments of Medicine, Division of Pulmonary and Critical Care Medicine (Dr. Staton), Radiology (Dr. Hu), Anesthesiology (Dr. Duke), Surgery, Division of Cardiothoracic Surgery (Drs. Puskas and Williams), the Emory Center for Outcomes Research (Dr. Williams), Emory University School of Medicine, Emory University, Atlanta, GA; Department of Epidemiology (Dr. Chu), Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; and the New England Research Institutes (Dr. Mahoney), Watertown, MA.

Correspondence to: Gerald W. Staton, Jr, MD, Professor of Medicine, Emory University School of Medicine, Medical Director, Wesley Woods Long Term Hospital, 1821 Clifton Rd NE, Atlanta, GA 30329; e-mail: gerald_staton{at}emoryhealthcare.org


   Abstract
TOP
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 References
 
Study objectives: Comparison of pulmonary outcomes after off-pump coronary artery bypass (OPCAB) vs on-pump coronary artery grafting with cardiopulmonary bypass (CABG/CPB).

Study design: We examined preoperative and postoperative respiratory compliance, fluid balance, hemodynamics, arterial blood gases, chest radiographs, spirometry, pulmonary complications, and time to extubation in a prospective trial of 200 patients randomized to OPCAB vs CABG/CPB performed by one surgeon.

Results: One CABG/CPB patient and two OPCAB patients required mitral valve repair or replacement and were withdrawn. After three crossovers from CABG/CBP to OPCAB and one crossover from OPCAB to CABG, 97 CABG/CPB patients and 100 OPCAB patients remained. There were no significant preoperative demographic differences between groups. Postoperative compliance was reduced more after OPCAB than after CABG/CPB (– 15.4 ± 10.7 mL/cm H2O vs – 11.2 ± 10.1 mL/cm H2O [mean ± SD]; p = 0.007), associated with rotation of the heart into the right chest to perform posterolateral bypasses (p < 0.001) and the concomitant increased fluid requirements necessary to maintain hemodynamic stability during rotation of the heart. In addition to higher intraoperative fluid intake (4,541 ± 1,311 mL vs 3,585 ± 1,033 mL, p < 0.0001), OPCAB patients had higher intraoperative fluid balance (3,903 ± 1,315 mL vs 1,772 ± 1,373 mL, p < 0.0001), and higher postoperative pulmonary arterial diastolic pressure (15.0 ± 5.5 mm Hg vs 11.8 ± 5.2 mm Hg, p < 0.0001) and central venous pressure (10.4 ± 4.5 mm Hg vs 8.4 ± 4.7 mm Hg, p < 0.0001). Despite lower compliance, immediate postoperative PaO2 on fraction of inspired oxygen of 1.0 (275 ± 97 torr vs 221 ± 92 torr, p = 0.001) was higher after OPCAB and extubation was earlier (p = 0.001). Postoperative chest radiographs, spirometry, mortality, reintubation, or readmission for pulmonary complications were not different between groups.

Conclusions: Compared to CABG/CPB, OPCAB was associated with a greater reduction in postoperative respiratory compliance associated with increased fluid administration and rotation of the heart into the right chest to perform posterolateral grafts. OPCAB yielded better gas exchange and earlier extubation but no difference in chest radiographs, spirometry, or rates of death, pneumonia, pleural effusion, or pulmonary edema.

Key Words: cardiopulmonary bypass • coronary artery surgery • off-pump coronary artery bypass • off-pump coronary arterial surgery • pulmonary surgical complications


   Introduction
TOP
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 References
 
Coronary artery bypass surgery performed with cardiopulmonary bypass (CPB) has been associated with significant pulmonary complications and functional changes. Many of these abnormalities are thought to be caused by CPB. Increases in lung vascular permeability1 occur after CPB and can result in the development of ARDS in 0.4 to 2.5% of patients.234 Atelectasis,56 alterations of lung function,789101112 and reduction in lung compliance13141516 and gas exchange651718 are also seen. Systemic inflammation319 as well as imbalance of oxidant/antioxidant120 and protease/antiprotease status21 induced by CPB have been implicated in producing these pathophysiologic abnormalities.

In the last several years, techniques to perform coronary artery bypass surgery without CPB have been developed.2223 Initial reports have detected reductions in indexes of systemic inflammation,2425 neutrophil activation,26 and improvement in renal and neurologic outcomes.2728 Retrospective analyses of databases comparing on-pump to off-pump surgery have suggested reductions in postoperative morbidity2930 including reductions in pulmonary complications.31

We performed the Surgical Management of Arterial Revascularization Therapies (SMART) trial,3233 a prospective, randomized controlled trial of off-pump coronary artery bypass (OPCAB) vs on-pump coronary artery grafting with CPB (CABG/CPB) performed by one surgeon at a single hospital. One aspect of the study, the pulmonary component, was the measurement of preoperative and postoperative lung function, gas exchange, respiratory static compliance, chest radiographic changes, and detection of pulmonary complications.34 Considering existing data regarding CPB, we anticipated that OPCAB would be associated with better lung function, earlier extubation, and reduced complications when compared to CABG/CPB.


   Materials and Methods
TOP
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 References
 
Patient Selection, Randomization, Care, and Data Collection
The SMART trial3233 was designed to compare completeness of revascularization, graft patency, clinical outcomes, and resource utilization in unselected patients referred for elective, primary coronary bypass surgery randomized to undergo OPCAB with a stabilization device (Octopus; Medtronic; Minneapolis, MN) or CABG/CPB at a single hospital by a single surgeon. Patients were not excluded on the basis of any preoperative comorbidities or any pattern of coronary artery disease.3233

Patients were randomized via computer-generated random-number table using a sealed envelope assignment. Randomization was stratified by sex and diabetes to ensure equal numbers of patients within strata defined by these prognostically relevant characteristics. Randomization was carried out separately within each stratum using randomly permuted blocks of size four and six to preserve approximate balance and prevent correct prediction of the next assignment by the clinical recruiting staff. The surgeon was informed of the randomization result in the operating room (OR) immediately prior to the beginning of the operation and after all the decisions on the planned revascularization had been made and documented.3233

Patient management was by a single team according to strict, unbiased, blinded, criteria-driven protocols.3233 Other than use of CPB in the CABG/CPB group and not in the OPCAB group, the protocols dictated three differences in care between the OPCAB group and the CABG/CPB group. Nondiabetic patients who were randomized to CABG/CPB received methylprednisolone sodium succinate, 250 mg IV, after line placement and prior to institution of CPB. The ventilatory strategy used in the OR differed slightly between the two groups. OPCAB patients, after paralysis and intubation, received mechanical ventilation with a fraction of inspired oxygen (FIO2) of 1.0, tidal volume of 10 to 12 mL/kg, and no positive end expiratory pressure (PEEP). CABG/CPB patients received mechanical ventilation with an FIO2 of 1.0, tidal volume of 10 to 12 mL/kg, and no PEEP until CPB was at full flow. At that point, the ventilator was turned off and the endotracheal tube was disconnected from the ventilator. At the end of CPB, the atelectatic lungs were manually ventilated until fully expanded visually, after which mechanical ventilation with FIO2 of 1.0, tidal volume of 10 to 12 mL/kg, and no PEEP was resumed. Finally, the need to rotate the heart into the right chest to facilitate grafts to the posterolateral vessels in the OPCAB group sometimes produced hemodynamic compromise necessitating extra IV fluids (IVFs) during this portion of the operation.

Data were recorded prospectively or contemporaneously by clinical research nurses on case report forms (CRFs) [Teleform; TeleForm Elite, Cardiff Software Ltd; Vista, CA]. Completed CRFs were logged, copied, filed, and transported to the Emory Center for Outcomes Research; each CRF was again logged and filed by the project data manager. The CRFs were electronically scanned, verified manually for scanning accuracy, and imported electronically into a relational database (Microsoft Access; Microsoft Corporation; Redmond, WA). Data integrity and completeness were monitored and maintained both manually and electronically.3233

The SMART trial3233 was approved by the Institutional Review Board of Emory University, Atlanta, GA. All patients signed approved informed consent prior to participation in the study.

Pulmonary Outcomes
Measurements of respiratory static compliance, fluid balance, hemodynamics, chest radiographic scoring, gas exchange, time to extubation, spirometry, and pulmonary complications were made (Table 1 ).


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  		Table 1.. Measurement Time Line

 
Respiratory Static Compliance
Presternotomy respiratory static compliance measurements were performed after paralysis, intubation, and induction of anesthesia but prior to sternal incision. Poststernotomy measurements were performed on closure of the sternum and verification of full muscle paralysis reversal by the anesthesiologist.

Measurements of expired tidal volume, PEEP, and static plateau pressure were made at predetermined tidal volumes of 500 mL, 750 mL, 1,000 mL, and 1,250 mL. For each measurement of expired tidal volume vs static plateau pressure and PEEP, the following steps were taken: (1) adjust tidal volume to the desired level; (2) manually cycle ventilator; (3) interrupt expiratory flow by pressing inspiratory pause button during inspiration; (4) at zero flow rate, record static plateau pressure; (5) release inspiratory pause button and record expired tidal volume; (6) record PEEP; (7) repeat process two times for a total of three measurements at each set tidal volume; and (8) repeat process for each of the four set tidal volume levels.

Fluid Balance and Hemodynamics
Fluid input and output were serially recorded in the OR. Pulmonary arterial and systemic arterial catheters were placed in the preoperative area, and serial measurements of mean arterial pressure, pulmonary arterial systolic pressure (PAS), pulmonary artery diastolic pressure (PAD), central venous pressure (CVP), cardiac output, and cardiac index (CI) were performed and recorded in the OR and in the ICU.

Chest Radiographs
Each patient had five serial chest radiographs (Table 1) scored by a single radiologist blinded to the surgical procedure (Table 2 ).


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  		Table 2.. Chest Radiographic Scoring System Protocol

 
Gas Exchange
Arterial blood was collected and analyzed on arrival in the preoperative holding area, in the OR immediately postoperatively on FIO2 of 1.0, and on postoperative day 3. Patients were transported to the preoperative holding area while breathing room air, and arterial blood gas (ABG) was measured before the patient was sedated and placed on oxygen (unless there was a known preoperative oxygen requirement).

The postoperative day 3 ABG was measured while breathing air or the lowest possible FIO2. The FIO2 was recorded for patients receiving supplemental oxygen by mask. For patients using a nasal cannula, the following FIO2 conversions were used: 1 L/min = 0.24, 2 L/min = 0.28, 3 L/min = 0.32, 4 L/min = 0.36, 5 L/min = 0.40, and 6 L/min = 0.44.

Extubation
Extubation was managed by protocol. All patients were evaluated for extubation in the OR. Criteria for extubation included reversal of paralysis, end-tidal isoflurane < 0.1%, appropriate response to simple commands, respiratory rate > 12 breaths/min, end-tidal CO2 < 50 mm Hg, ability to lift the head off the OR table for > 5 s, and a oxygen saturation by pulse oximetry > 95% on FIO2 of 1.0. If extubation in the OR failed, the patient was transported to the surgical ICU and again evaluated for extubation. The goal for extubation of each patient was within 4 h of arrival in the ICU.

Spirometry
Spirometry was done according to American Thoracic Society criteria preoperatively and again 4 to 6 weeks postoperatively.

Data Analysis
All data analysis was according to protocol, ie, according to the actual treatment the patients received: CABG/CPB or OPCAB. Discrete data are presented as percentages; continuous data are presented as mean ± SD. Dichotomous outcomes were analyzed by Fisher exact test. Continuous data were analyzed by the Wilcoxon rank-sum test. Changes from baseline in continuous variables were analyzed using analysis of covariance (ANCOVA), adjusting for baseline. Chest radiographic data relating to pulmonary edema were analyzed using the Cochran-Mantel-Haenszel test for trend. All statistical analyses were performed using software (SAS System for Windows Release 8.02; SAS Institute; Cary, NC; or S-Plus Professional Release 3; Mathsoft Engineering and Education; Cambridge, MA).

Presternotomy and poststernotomy respiratory static compliance curves were obtained for each patient. The three pressure measurements made at each predetermined tidal volume were averaged for this analysis. A fifth point was calculated corresponding to the average PEEP from the measurements at set tidal volume of 500 mL and the volume equal to zero (corresponding to functional residual capacity). For the other four points, the pressure was calculated as the average of the three pressure measurements minus PEEP, at predetermined volumes of 500 mL, 750 mL, 1,000 mL, and 1,250 mL, respectively. A simple linear regression of volume as a linear function of pressure, using the five data points, was used to estimate the slope parameter (compliance) for each patient.

ANCOVA was used to examine factors associated with the change in compliance (poststernotomy minus presternotomy compliance curve slopes) after adjusting for baseline (presternotomy slope). Covariates considered in the ANCOVA models were as follows: treatment assignment (off-pump vs on-pump), an indicator variable for grafts to the lateral wall, an indicator variable for heart displaced into right pleural cavity, smoking status (current smoker vs not current smoker), age at baseline, IVFs received in OR (milliliters), net fluid balance (total fluids received minus total fluids out, milliliters), and amount of cell saver (milliliters) and packed RBCs received in the OR. In the first stage of the analysis, models were fit including each of those variables separately, in addition to baseline compliance. In the second stage, multivariable models were fit to examine the independent effect of factors found significant in the first stage. Effects are considered significant if p < 0.05. All numeric data are presented as mean ± SD unless otherwise indicated.


   Results
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 References
 
Patients
Two hundred patients agreed to participate. Three patients were determined by transesophageal echocardiography after randomization and induction of anesthesia to require mitral valve repair or replacement and were withdrawn from the study. The study groups were 99 patients who were to undergo CABG/CPB and 98 patients who were to undergo OPCAB. Three patients had severe aortic calcification or atherosclerosis by epiaortic ultrasound and/or transesophageal echocardiography after randomization in the OR and, by protocol, crossed over to OPCAB. One OPCAB patient crossed over to CABG/CPB because of an intraoperative tear in the right ventricle.

Both intention-to-treat and per-protocol analyses were conducted. Per-protocol analysis assigned crossovers to the group representing the actual procedure each patient received, ie, OPCAB (100 patients) or CABG/CPB (97 patients). Results of these two analyses did not differ substantively. Data presented derive from the per-protocol analysis.

Demographics
The patients in the two groups were well matched for all important demographic and clinical characteristics (Table 3 ). There were no significant preoperative group differences in age, diagnosis of COPD, smoking status, preoperative New York Heart Association class, chest radiographic scores, spirometry, ABG levels, respiratory compliance, or hemodynamics.


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  		Table 3.. Demographics and Clinical Characteristics*

 
Respiratory Static Compliance
Respiratory static compliance was reduced postoperatively in both CABG/CPB and OPCAB patients (Fig 1 ). Postoperative compliance was reduced more in the OPCAB group than in the CABG/CPB group (– 15.4 ± 10.7 mL/cm H2O vs – 11.2 ± 10.1 mL/cm H2O, p = 0.007).



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  		Figure 1.. Presternotomy (Pre-Op) and poststernotomy (Post-Op) respiratory static compliance in the OPCAB and CABG/CPB groups. *Presternotomy to poststernotomy change in respiratory compliance was greater in the OPCAB group (p = 0.017 by two-sample, unpaired t test). {ddagger}Poststernotomy respiratory compliance was reduced compared to presternotomy static respiratory compliance in both groups (p < 0.001 by paired t test).

 
Causes of the greater change in compliance in the OPCAB group were examined by ANCOVA. The following factors were associated with significant decreases in respiratory static compliance when included in models individually, after adjusting for baseline compliance: off-pump procedure (vs on-pump procedure, ß = – 3.70; p = 0.0016), increasing IVFs (ß = – 0.00142; p = 0.006), net fluid balance (ß = – 0.001; p = 0.004), and the heart being placed in the right chest (ß = – 4.47; p < 0.001).

Multivariate analysis revealed that when the treatment group was included in a model along with the indicator for the heart being placed in the right chest, the heart in the right chest remained significant while the treatment group did not, suggesting that the influence of the off-pump technique on change in compliance is due to the heart being placed in the right chest (Table 4 , model 1). Two thirds of OPCAB patients had their hearts placed in the right chest (vs none in the on-pump group). When the heart placed in the right chest was included in a model that also included IVFs or net fluid balance, the heart in the right chest remained a significant predictor of change in respiratory static compliance while IVFs or net fluid balance did not (Table 4; models 2 and 3, respectively).


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  		Table 4.. ANCOVA Models Examining Factors Associated With Change in Pulmonary Static Compliance*

 
Intraoperative Fluid Balance
The OPCAB patients received more intraoperative IVFs and total fluids. The OPCAB patients also had less urine output and net output, ie, greater net intake/output ratio for the OPCAB group (Table 5 ). Patients in the OPCAB group who had the heart placed in the right chest had more IVFs (4,124 ± 936 mL vs 3,547 ± 1,269 mL, p = 0.0038) and total fluids (4,214 ± 1,043 mL vs 3,191 ± 1,540 mL, p < 0.001) than did the OPCAB patients who did not require this maneuver for exposure of posterolateral vessels.


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  		Table 5.. OR IVFs and Net Fluid Balance*

 
Preoperative and Postoperative Hemodynamics
The OPCAB group had higher immediate postoperative PADs (15.0 ± 5.5 mm Hg vs 11.8 ± 5.2 mm Hg, p < 0.001) and CVPs (10.4 ± 4.5 mm Hg vs 8.4 ± 4.7 mm Hg, p < 0.001). The postoperative CI in the OPCAB group was lower than in the CABG/CPB group (Table 6 ).


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  		Table 6.. Presternotomy and Immediate Poststernotomy Hemodynamics*

 
Chest Radiographs
The postoperative chest radiographs showed no differences between the groups in the rates of atelectasis, pleural effusions, pneumothorax, pulmonary edema, alveolar consolidation, and composite radiographic score (Table 7 ).


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  		Table 7.. Chest Radiographic Pulmonary Edema Findings*

 
Gas Exchange
Despite lower respiratory static compliance, OPCAB patients had better immediate postoperative PaO2 (in the OR, intubated, FIO2 of 1.0) and alveolar-arterial oxygen pressure difference (P[A-a]O2) [275 ± 97 torr vs 221 ± 92 torr, p = 0.001]. By postoperative day 3, these differences no longer existed (Table 8 ).


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  		Table 8.. Gas Exchange*

 
Time to Extubation
A marginally greater number of OPCAB patients were extubated in the OR (45 of 100 patients vs 32 of 97 patients, p = 0.108). More OPCAB patients were extubated in < 4 h (73 of 100 patients vs 50 of 97 patients, p = 0.002) [Table 9 ]. A few more CABG/CPB patients remained intubated ≥ 24 h postoperatively (0 of 100 patients vs 5 of 97 patients, p = 0.027).32


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  		Table 9.. Extubation and Reintubation*

 
There was no difference in the reintubation rate: OPCAB, 5 of 100 patients; CABG/CPB, 4 of 97 patients (p = not significant [NS]). OPCAB patients were intubated for fewer hours: CABG/CPB, 12.8 ± 30.1 h (median, 4.58 h); OPCAB, 5.2 ± 10.3 h (median, 3.39 h) [p = 0.008 by Fisher exact test; Table 9].

Spirometry
FVC and FEV1 were significantly reduced postoperatively in both groups, but not the FEV1/FVC ratio. There were no differences in postoperative spirometry measures between the groups or in the magnitude of the change after surgery (Table 10 ).


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  		Table 10.. Preoperative and 4- to 6-Week Postoperative Spirometry*

 
Mortality and Readmissions
There were no differences in mortality or in readmissions for pulmonary edema, pneumonia, and pleural effusion (Table 11 ).


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  		Table 11.. Mortality and Pulmonary Readmissions Within 30 Days*

 

   Discussion
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
References
 
This is the largest prospective randomized trial to date to provide comprehensive analysis of the pulmonary aspects of OPCAB vs CABG/CPB. We have demonstrated that a greater decrease in postoperative respiratory static compliance seen in the OPCAB patients appears to be due to the need to rotate the heart into the right chest to allow bypass to posterolateral vessels and the larger amounts of IVF required to maintain systemic BP during the operation. Paradoxically, CABG/CPB patients actually had poorer gas exchange immediately postoperatively, and their extubation was delayed by ABG-based protocol even though they had no signs of pulmonary edema and a smaller decrease in compliance. The explanation for these observations may lie in some aspect of CPB including release of inflammatory mediators or possible failure of replenishment of surfactant due to the lack of ventilatory cycling of the lung. There were no differences in reintubation rate, readmissions to the hospital for respiratory complications, or mortality between the groups.

In several published randomized trials28353637 of off-pump vs on-pump coronary bypass in which specific pulmonary effects were not measured, there were no differences in the number of patients requiring > 24 h of intubation. The off-pump patients in the study by Van Dijk et al35 gained weight while the on-pump patients lost weight, suggesting that the off-pump patients received more fluids, as documented in the SMART trial.

Guler et al38 focused on patients with severe COPD, randomizing patients to OPCAB, CABG/CPB, or minimally invasive direct coronary artery bypass groups. There was a slight reduction in atelectasis, duration of intubation, and time spent in the ICU in the OPCAB and minimally invasive direct coronary artery bypass groups compared to the CABG/CPB group.38 At 8 weeks postoperatively, no differences in gas exchange were seen between the treatment groups but the CABG/CPB patients had a greater reduction in FEV1 and FEV1/FVC ratio.38

In nonrandomized studies, Roosens et al39 and Babik et al40 compared the time course of respiratory mechanics before and after CABG/CPB and OPCAB. Both studies found increases in respiratory elastance, ie, decreases in respiratory compliance, due to changes both in lung elastance and chest wall elastance that improved over time after surgery; no differences were seen between the OPCAB and CABG/CPB patients. In contrast to the SMART trial, although fluid balance between the OPCAB and CABG/CPB groups was not different, Roosens et al39 did find a correlation between positive fluid balance and changes in chest wall elastance similar to those changes we report here. Tschernko et al41 demonstrated that immediate postoperative oxygenation and shunt fraction were better in the OPCAB group. Cimen et al42 found no significant differences between OPCAB and CABG/CPB groups in gas exchange, spirometry, time to extubation, or pulmonary complications. In the four retrospective analyses29304344 of large clinical databases, three of the four studies293044 examined time to extubation and found for OPCAB reductions either in time to extubation or in the number of patients requiring intubation for > 24 h.

In future studies of OPCAB, techniques to reduce the need for rotation of the heart into the right chest and reduction in IVF administration during OPCAB should be examined as methods to reduce the compliance changes seen here in the OPCAB group. Suction-based apical cardiac positioning devices that allow rotation of the heart and exposure of the posterolateral wall coronary arteries for grafting with less hemodynamic compromise and consequent fluid requirements have been introduced since the completion of the SMART trial. Alternative intraoperative ventilatory strategies including maintenance of lung expansion with continuous airway pressure or oscillatory cycling might eliminate the early postoperative gas exchange abnormalities seen in the SMART trial.


   Acknowledgements
 
We are indebted to Roland H. Ingram, MD, for his helpful discussions of the respiratory static compliance data and review of the manuscript, and we also thank Kenneth V. Leeper, MD, and Bruce Krieger, MD, for their helpful comments. We could not have performed this study without the help of our nurse coordinators, Susan A. McCall, RN, Bonnie Sammons, RN, and Rebecca J. Peterson, RN.


   Footnotes
 
Abbreviations: ABG = arterial blood gas; ANCOVA = analysis of covariance; CABG/CPB = on-pump coronary artery grafting with cardiopulmonary bypass; CI = cardiac index; CPB = cardiopulmonary bypass; CRF = case report forms; CVP = central venous pressure; FIO2 = fraction of inspired oxygen; IVF = IV fluid; NS = not significant; OPCAB = off-pump coronary artery bypass; OR = operating room; P(A-a)O2 = alveolar-arterial oxygen pressure difference; PAD = pulmonary artery diastolic pressure; PAS = pulmonary artery systolic pressure; PEEP = positive end-expiratory pressure; SMART = Surgical Management of Arterial Revascularization Therapies

Dr. Duke has received consultant fees from Medtronic, Inc., and Dr. Puskas has received consultant fees and speaker honoraria from Medtronic, Inc.

This study was supported by grants from Medtronic, Inc, Minneapolis, MN; and The Carlyle Fraser Heart Center Foundation, Atlanta, GA.

Received for publication February 23, 2004. Accepted for publication September 17, 2004.


   References
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

  1. Messent, M, Sinclair, DG, Quinlan, GJ, et al (1997) Pulmonary vascular permeability after cardiopulmonary bypass and its relationship to oxidative stress. Crit Care Med 25,425-429[CrossRef][ISI][Medline]
  2. Kaul, TK, Fields, BL, Riggins, LS, et al Adult respiratory distress syndrome following cardiopulmonary bypass: incidence, prophylaxis and management. J Cardiovasc Surg 1998;39,777-781[Medline]
  3. Asimakopoulos, G, Smith, PL, Ratnatunga, CP, et al Lung injury and acute respiratory distress syndrome after cardiopulmonary bypass. Ann Thorac Surg 1999;68,1107-1115[Abstract/Free Full Text]
  4. Milot, J, Perron, J, Lacasse, Y, et al Incidence and predictors of ARDS after cardiac surgery. Chest 2001;119,884-888[Abstract/Free Full Text]
  5. Pinilla, JC, Oleniuk, FH, Tan, L, et al Use of a nasal continuous positive airway pressure mask in the treatment of postoperative atelectasis in aortocoronary bypass surgery. Crit Care Med 1990;18,836-840[ISI][Medline]
  6. Tenling, A, Hachenberg, T, Tyden, H, et al Atelectasis and gas exchange after cardiac surgery. Anesthesiology 1998;89,371-378[CrossRef][ISI][Medline]
  7. Braun, SR, Birnbaum, ML, Chopra, PS Pre- and postoperative pulmonary function abnormalities in coronary artery revascularization surgery. Chest 1978;73,316-320[Abstract/Free Full Text]
  8. Van Belle, AF, Wesseling, GJ, Penn, OC, et al Postoperative pulmonary function abnormalities after coronary artery bypass surgery. Respir Med 1992;86,195-199[ISI][Medline]
  9. Shenkman, Z, Shir, Y, Weiss, YG, et al The effects of cardiac surgery on early and late pulmonary functions. Acta Anaesthesiol Scand 1997;41,1193-1199[ISI][Medline]
  10. Nicholson, DJ, Kowalski, SE, Hamilton, GA, et al Postoperative pulmonary function in coronary artery bypass graft surgery patients undergoing early tracheal extubation: a comparison between short-term mechanical ventilation and early extubation. J Cardiothorac Vasc Anesth 2002;16,27-31[CrossRef][ISI][Medline]
  11. Vargas, FS, Terra-Filho, M, Hueb, W, et al Pulmonary function after coronary artery bypass surgery. Respir Med 1997;91,629-633[CrossRef][ISI][Medline]
  12. Macguire, B, Royse, C, Royse, A, et al Lung function following cardiac surgery is not affected by postoperative ventilation time. Ann Thorac Cardiovasc Surg 2000;6,13-18[Medline]
  13. Auler, JO, Jr, Zin, W, Caldeira, M, et al Pre- and postoperative inspiratory mechanics in ischemic and valvular heart disease. Chest 1987;92,984-990[Abstract/Free Full Text]
  14. Polese, G, Lubli, P, Mazzucco, A, et al Effects of open heart surgery on respiratory mechanics. Intensive Care Med 1999;25,1092-1099[CrossRef][ISI][Medline]
  15. Auler, JO, Jr, Carmona, MJ, Barbas, CV, et al The effects of positive end-expiratory pressure on respiratory system mechanics and hemodynamics in postoperative cardiac surgery patients. Braz J Med Biol Res 2000;33,31-42[ISI][Medline]
  16. Ranieri, V, Vitale, N, Grasso, S, et al Time-course of impairment of respiratory mechanics after cardiac surgery and cardiopulmonary bypass. Crit Care Med 1999;27,1454-1460[CrossRef][ISI][Medline]
  17. Anjou-Lindskog, E, Broman, L, Broman, M, et al Effects of oxygen on central haemodynamics and VA/Q distribution after coronary bypass surgery. Acta Anaesthesiol Scand 1983;27,378-384[ISI][Medline]
  18. Macnaughton, PD, Braude, S, Hunter, DN, et al Changes in lung function and pulmonary capillary permeability after cardiopulmonary bypass. Crit Care Med 1992;20,1289-1294[ISI][Medline]
  19. Paparella, D, Yau, TM, Young, E Cardiopulmonary bypass induced inflammation: pathophysiology and treatment; an update. Eur J Cardiothorac Surg 2002;21,232-244[Abstract/Free Full Text]
  20. Quinlan, GJ, Mumby, S, Lamb, NJ, et al Acute respiratory distress syndrome secondary to cardiopulmonary bypass: do compromised plasma iron-binding anti-oxidant protection and thiol levels influence outcome? Crit Care Med 2000;28,2271-2276[CrossRef][ISI][Medline]
  21. Frass, OM, Buhling, F, Tager, M, et al Antioxidant and antiprotease status in peripheral blood and BAL fluid after cardiopulmonary bypass. Chest 2001;120,1599-1608[Abstract/Free Full Text]
  22. Bredee, JJ, Jansen, EW Coronary artery bypass grafting without cardiopulmonary bypass. Curr Opin Cardiol 1998;13,476-482[ISI][Medline]
  23. Hart, JC, Puskas, JD, Sabik, JF, III Off-pump coronary revascularization: current state of the art. Semin Thorac Cardiovasc Surg 2002;14,70-81[CrossRef][Medline]
  24. Brasil, LA, Gomes, WJ, Salomao, R, et al Inflammatory response after myocardial revascularization with or without cardiopulmonary bypass. Ann Thorac Surg 1998;66,56-59[Abstract/Free Full Text]
  25. Ascione, R, Lloyd, CT, Underwood, MJ, et al Inflammatory response after coronary revascularization with or without cardiopulmonary bypass. Ann Thorac Surg 2000;69,1198-1204[Abstract/Free Full Text]
  26. Fransen, E, Maessen, J, Dentener, M, et al Systemic inflammation present in patients undergoing CABG without extracorporeal circulation. Chest 1998;113,1290-1295[Abstract/Free Full Text]
  27. Ascione, R, Lloyd, CT, Underwood, MJ, et al On-pump versus off-pump coronary revascularization: evaluation of renal function. Ann Thorac Surg 1999;68,493-498[Abstract/Free Full Text]
  28. Van Dijk, D, Jansen, EW, Hijman, R, et al Cognitive outcome after off-pump and on-pump coronary artery bypass graft surgery: a randomized trial. JAMA 2002;287,1405-1412[Abstract/Free Full Text]
  29. Baumgartner, FJ, Yokoyama, T, Gheissari, A, et al Effect of off-pump coronary artery bypass grafting on morbidity. Am J Cardiol 2000;86,1021-1022[CrossRef][ISI][Medline]
  30. Al-Ruzzeh, S, Nakamura, K, Athanasiou, T, et al Does off-pump coronary artery bypass (OPCAB) surgery improve the outcome in high-risk patients? A comparative study of 1,398 high-risk patients. Eur J Cardiothorac Surg 2003;23,50-55[Abstract/Free Full Text]
  31. Yokoyama, T, Baumgartner, FJ, Gheissari, A, et al Off-pump versus on-pump coronary bypass in high-risk subgroups. Ann Thorac Surg 2000;70,1546-1550[Abstract/Free Full Text]
  32. Puskas, JD, Williams, WH, Duke, PG, et al Off-pump coronary artery bypass grafting provides complete revascularization with reduced myocardial injury, transfusion requirements, and length of stay: a prospective randomized comparison of two hundred unselected patients undergoing off-pump versus conventional coronary artery bypass grafting. J Thorac Cardiovasc Surg 2003;125,797-808[Abstract/Free Full Text]
  33. Puskas, JD, Williams, WH, Mahoney, EM, et al Off-pump vs conventional coronary artery bypass grafting: early and 1-year graft patency, cost, and quality-of-life; a randomized trial. JAMA 2004;291,1841-1849[Abstract/Free Full Text]
  34. Staton, GW, Mahoney, EM, Williams, WH, et al Off-pump (OPCAB) vs on-pump coronary artery bypass surgery (CABG/CPB): spirometry, respiratory compliance, (Cs), gas exchange, and pulmonary complications in a randomized trial [abstract]. Chest 2003;124,104S
  35. Van Dijk, D, Nierich, AP, Jansen, EW, et al Early outcome after off-pump versus on-pump coronary bypass surgery: results from a randomized study. Circulation 2001;104,1761-1766[Abstract/Free Full Text]
  36. Cox, CM, Ascione, R, Cohen, AM, et al Effect of cardiopulmonary bypass on pulmonary gas exchange: a prospective randomized study. Ann Thorac Surg 2000;69,140-145[Abstract/Free Full Text]
  37. Khan, N, De Souza, A, Mister, R, et al A randomized comparison of off-pump and on-pump coronary-artery bypass surgery. N Engl J Med 2004;350,21-28[Abstract/Free Full Text]
  38. Guler, M, Kirali, K, Toker, ME, et al Different CABG methods in patients with chronic obstructive pulmonary disease. Ann Thorac Surg 2001;71,152-157[Abstract/Free Full Text]
  39. Roosens, C, Heerman, J, De Somer, F, et al Effects of off-pump coronary surgery on the mechanics of the respiratory system, lung, and chest wall: Comparison with extracorporeal circulation. Crit Care Med 2002;30,2430-2437[CrossRef][ISI][Medline]
  40. Babik, B, Asztalos, T, Petak, F, et al Changes in respiratory mechanics during cardiac surgery. Anesth Analg 2003;96,1280-1287[Abstract/Free Full Text]
  41. Tschernko, EM, Bambazek, A, Wisser, W, et al Intrapulmonary shunt after cardiopulmonary bypass: the use of vital capacity maneuvers versus off-pump coronary artery bypass grafting. J Thorac Cardiovasc Surg 2002;124,732-738[Abstract/Free Full Text]
  42. Cimen, S, Ozkul, V, Ketenci, B, et al Daily comparison of respiratory functions between on-pump and off-pump patients undergoing CABG. Eur J Cardiothorac Surg 2003;23,589-594[Abstract/Free Full Text]
  43. Puskas, JD, Thourani, VH, Marshall, JJ, et al Clinical outcomes, angiographic patency, and resource utilization in 200 consecutive off-pump coronary bypass patients. Ann Thorac Surg 2001;71,1477-1483[Abstract/Free Full Text]
  44. Magee, MJ, Jablonski, KA, Stamou, SC, et al Elimination of cardiopulmonary bypass improves early survival for multivessel coronary artery bypass patients. Ann Thorac Surg 2002;73,1196-1202[Abstract/Free Full Text]



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