Open-Lung Ventilation Improves Clinical Outcomes in Off-Pump Coronary Artery Bypass Surgery: A Randomized Controlled Trial.

OBJECTIVE: To compare pulmonary function, functional capacity, and clinical outcomes among conventional mechanical ventilation (CMV), early open-lung (EOL), and late open-lung (LOL) strategies after off-pump coronary artery bypass surgery (OPCAB). DESIGN: Prospective, randomized, and double-blinded study. SETTING: Two hospitals of the Federal University of Sao Paulo, Brazil. PARTICIPANTS: Ninety-three patients undergoing elective first-time OPCAB. INTERVENTIONS: Patients were randomized into 3 groups: CMV (n=31); LOL (n=32) initiated upon intensive care unit (ICU) arrival; EOL (n = 30) initiated after intubation. MEASURAMENTS AND MAIN RESULTS: Spirometry was performed at bedside preoperatively and on postoperative days (PODs) 1, 3, and 5. Partial pressure of arterial oxygen (PaO2) and pulmonary shunt fraction were evaluated presurgically and on POD 1; 6-minute walk test (6MWT) was performed presurgically and on POD 5. Both open-lung groups demonstrated higher forced vital capacity and forced expiratory volume in 1 second on PODs 1, 3 and 5 compared to the CMV group (p<0.05). Similar results were found in relation to the 6MWT distance. Shunt fraction was lower and PaO2 was higher in both open-lung groups (p<0.05). Open-lung groups had shorter intubation time and hospital stay as well as fewer respiratory events (p<0.05). No statistical difference was found relative to the aforementioned results when the EOL and LOL groups were compared. CONCLUSIONS: Both open-lung strategies were able to promote higher pulmonary function preservation and greater recovery of functional capacity with better clinical outcomes after OPCAB. No difference in outcome was found when comparing initiation of OLS intraoperatively or after ICU arrival.

Extended-time of Noninvasive Positive Pressure Ventilation Improves Tissue Perfusion after Coronary Artery Bypass Surgery: a Randomized Clinical Trial.

OBJECTIVE: To compare the effects of extended- versus short-time noninvasive positive pressure ventilation on pulmonary function, tissue perfusion, and clinical outcomes in the early postoperative period following coronary artery bypass surgery in patients with preserved left ventricular function. METHODS: Patients were randomized into two groups according to noninvasive positive pressure ventilation intensity: short-time noninvasive positive pressure ventilation n=20 (S-NPPV) and extended-time noninvasive positive pressure ventilation n=21 (E-NPPV). S-NPPV was applied for 60 minutes during immediate postoperative period and 10 minutes, twice daily, from postoperative days 1-5. E-NPPV was performed for at least six hours during immediate postoperative period and 60 minutes, twice daily, from postoperative days 1-5. As a primary outcome, tissue perfusion was determined by central venous oxygen saturation and blood lactate level measured after anesthetic induction, immediately after extubation and following noninvasive positive pressure ventilation protocols. As a secondary outcome, pulmonary function tests were performed preoperatively and in the postoperative days 1, 3, and 5; clinical outcomes were recorded. RESULTS: Significant drop in blood lactate levels and an improvement in central venous oxygen saturation values in the E-NPPV group were observed when compared with S-NPPV group after study protocol (P<0.01). The E-NPPV group presented higher preservation of postoperative pulmonary function as well as lower incidence of respiratory events and shorter postoperative hospital stay (P<0.05). CONCLUSION: Prophylactic E-NPPV administered in the early postoperative period of coronary artery bypass surgery resulted in greater improvements in tissue perfusion, pulmonary function and clinical outcomes than S-NPPV, in patients with preserved left ventricular function. TRIAL REGISTRATION: Brazilian Registry of Clinical trial - RBR7sqj78 - http://www.ensaiosclinicos.gov.br.

Noninvasive Ventilation After Coronary Artery Bypass Grafting in Subjects With Left-Ventricular Dysfunction.

BACKGROUND: The use of noninvasive ventilation in patients with left-ventricular dysfunction may increase cardiac performance by decreasing inspiratory effort and left-ventricular afterload. The aim of the present study was to evaluate the acute effects of noninvasive ventilation on central-venous oxygen saturation (Scv̄O2 ) and blood lactate in subjects with left-ventricular dysfunction during the early postoperative phase of coronary artery bypass grafting. METHODS: This study included 100 subjects during the postoperative phase of elective coronary artery bypass grafting. Blood samples, at 5 time points, were collected to assess tissue perfusion markers (ie, Scv̄O2 and blood lactate) as follows: (1) the intraoperative period (after anesthesia induction); (2) 20 min after ICU arrival, under intermittent mandatory ventilation; (3) 20 min after extubation with spontaneous breathing; (4) after 1 h of noninvasive ventilation; and (5) 20 min after discontinuation of noninvasive ventilation. RESULTS: A significant increase in the blood lactate and a drop in the Scv̄O2 were observed on arrival to the ICU compared with intraoperative values (P < .001). After extubation, during spontaneous breathing, the Scv̄O2 significantly decreased (P = .02), whereas the blood lactate increased, although not significantly (P = .21) compared with intermittent mandatory ventilation on arrival to the ICU. During the application of noninvasive ventilation, the Scv̄O2 significantly increased (P = .048) and the blood lactate significantly decreased (P = .008) compared with spontaneous breathing values after extubation. After noninvasive ventilation discontinuation, the Scv̄O2 and blood lactate did not change compared with measures taken during noninvasive ventilation; higher values of Scv̄O2 were maintained compared with those obtained after extubation (P < .001). CONCLUSIONS: The acute application of noninvasive ventilation improved Scv̄O2 and decreased the blood lactate in subjects with left-ventricular dysfunction during the early postoperative phase after coronary artery bypass grafting. (ClinicalTrials.gov registration NCT02767687.).

Early Open-Lung Ventilation Improves Clinical Outcomes in Patients with Left Cardiac Dysfunction Undergoing Off-Pump Coronary Artery Bypass: a Randomized Controlled Trial.

Objective: To compare pulmonary function, functional capacity and clinical outcomes amongst three groups of patients with left ventricular dysfunction following off-pump coronary artery bypass, namely: 1) conventional mechanical ventilation (CMV); 2) late open lung strategy (L-OLS); and 3) early open lung strategy (E-OLS). Methods: Sixty-one patients were randomized into 3 groups: 1) CMV (n=21); 2) L-OLS (n=20) initiated after intensive care unit arrival; and 3) E-OLS (n=20) initiated after intubation. Spirometry was performed at bedside on preoperative and postoperative days (PODs) 1, 3, and 5. Partial pressure of arterial oxygen (PaO2) and pulmonary shunt fraction were evaluated preoperatively and on POD1. The 6-minute walk test was applied on the day before the operation and on POD5. Results: Both the open lung groups demonstrated higher forced vital capacity and forced expiratory volume in 1 second on PODs 1, 3 and 5 when compared to the CMV group (P<0.05). The 6-minute walk test distance was more preserved, shunt fraction was lower, and PaO2 was higher in both open-lung groups (P<0.05). Open-lung groups had shorter intubation time and hospital stay and also fewer respiratory events (P<0.05). Key measures were significantly more favorable in the E-OLS group compared to the L-OLS group. Conclusion: Both OLSs (L-OLS and E-OLS) were able to promote higher preservation of pulmonary function, greater recovery of functional capacity and better clinical outcomes following off-pump coronary artery bypass when compared to conventional mechanical ventilation. However, in this group of patients with reduced left ventricular function, initiation of the OLS intra-operatively was found to be more beneficial and optimal when compared to OLS initiation after intensive care unit arrival.

Extended-time of noninvasive positive pressure ventilation improves tissue perfusion after coronary artery bypass surgery: a randomized clinical trial

Abstract Objective: To compare the effects of extended- versus short-time noninvasive positive pressure ventilation on pulmonary function, tissue perfusion, and clinical outcomes in the early postoperative period following coronary artery bypass surgery in patients with preserved left ventricular function. Methods: Patients were randomized into two groups according to noninvasive positive pressure ventilation intensity: short-time noninvasive positive pressure ventilation n=20 (S-NPPV) and extended-time noninvasive positive pressure ventilation n=21 (E-NPPV). S-NPPV was applied for 60 minutes during immediate postoperative period and 10 minutes, twice daily, from postoperative days 1-5. E-NPPV was performed for at least six hours during immediate postoperative period and 60 minutes, twice daily, from postoperative days 1-5. As a primary outcome, tissue perfusion was determined by central venous oxygen saturation and blood lactate level measured after anesthetic induction, immediately after extubation and following noninvasive positive pressure ventilation protocols. As a secondary outcome, pulmonary function tests were performed preoperatively and in the postoperative days 1, 3, and 5; clinical outcomes were recorded. Results: Significant drop in blood lactate levels and an improvement in central venous oxygen saturation values in the E-NPPV group were observed when compared with S-NPPV group after study protocol (P<0.01). The E-NPPV group presented higher preservation of postoperative pulmonary function as well as lower incidence of respiratory events and shorter postoperative hospital stay (P<0.05). Conclusion: Prophylactic E-NPPV administered in the early postoperative period of coronary artery bypass surgery resulted in greater improvements in tissue perfusion, pulmonary function and clinical outcomes than S-NPPV, in patients with preserved left ventricular function. Trial Registration: Brazilian Registry of Clinical trial - RBR7sqj78 - http://www.ensaiosclinicos.gov.br

Early open-lung ventilation improves clinical outcomes in patients with left cardiac dysfunction undergoing off-pump coronary artery bypass: a randomized controlled trial

Abstract Objective: To compare pulmonary function, functional capacity and clinical outcomes amongst three groups of patients with left ventricular dysfunction following off-pump coronary artery bypass, namely: 1) conventional mechanical ventilation (CMV); 2) late open lung strategy (L-OLS); and 3) early open lung strategy (E-OLS). Methods: Sixty-one patients were randomized into 3 groups: 1) CMV (n=21); 2) L-OLS (n=20) initiated after intensive care unit arrival; and 3) E-OLS (n=20) initiated after intubation. Spirometry was performed at bedside on preoperative and postoperative days (PODs) 1, 3, and 5. Partial pressure of arterial oxygen (PaO2) and pulmonary shunt fraction were evaluated preoperatively and on POD1. The 6-minute walk test was applied on the day before the operation and on POD5. Results: Both the open lung groups demonstrated higher forced vital capacity and forced expiratory volume in 1 second on PODs 1, 3 and 5 when compared to the CMV group (P<0.05). The 6-minute walk test distance was more preserved, shunt fraction was lower, and PaO2 was higher in both open-lung groups (P<0.05). Open-lung groups had shorter intubation time and hospital stay and also fewer respiratory events (P<0.05). Key measures were significantly more favorable in the E-OLS group compared to the L-OLS group. Conclusion: Both OLSs (L-OLS and E-OLS) were able to promote higher preservation of pulmonary function, greater recovery of functional capacity and better clinical outcomes following off-pump coronary artery bypass when compared to conventional mechanical ventilation. However, in this group of patients with reduced left ventricular function, initiation of the OLS intra-operatively was found to be more beneficial and optimal when compared to OLS initiation after intensive care unit arrival.