The Effect of Low Tidal Volume Ventilation on Inflammatory Cytokines During Cardiopulmonary Bypass (original) (raw)
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Cardiovascular Journal Of Africa, 2013
Introduction: Cardiopulmonary bypass causes a series of inflammatory events that have adverse effects on the outcome. The release of cytokines, including interleukins, plays a key role in the pathophysiology of the process. Simultaneously, cessation of ventilation and pulmonary blood flow contribute to ischaemia-reperfusion injury in the lungs when reperfusion is maintained. Collapse of the lungs during cardiopulmonary bypass leads to postoperative atelectasis, which correlates with the amount of intrapulmonary shunt. Atelectasis also causes post-perfusion lung injury. In this study, we aimed to document the effects of continued low-frequency ventilation on the inflammatory response following cardiopulmonary bypass and on outcomes, particularly pulmonary function. Methods: Fifty-nine patients subjected to elective coronary bypass surgery were prospectively randomised to two groups, continuous ventilation (5 ml/kg tidal volume, 5/min frequency, zero end-expiratory pressure) and no ventilation, during cardiopulmonary bypass. Serum interleukins 6, 8 and 10 (as inflammatory markers), and serum lactate (as a marker for pulmonary injury) levels were studied, and alveolararterial oxygen gradient measurements were made after the induction of anaesthesia, and immediately, one and six hours after the discontinuation of cardiopulmonary bypass. Results: There were 29 patients in the non-ventilated and 30 in the continuously ventilated groups. The pre-operative demographics and intra-operative characteristics of the patients were comparable. The serum levels of interleukin 6 (IL-6) increased with time, and levels were higher in the nonventilated group only immediately after discontinuation of cardiopulmonary bypass. IL-8 levels significantly increased only in the non-ventilated group, but the levels did not differ between the groups. Serum levels of IL-10 and lactate also increased with time, and levels of both were higher in the non-ventilated group only immediately after the discontinuation of cardiopulmonary bypass. Alveolar-arterial oxygen gradient measurements were higher in the non-ventilated group, except for six hours after the discontinuation of cardiopulmonary bypass. The intubation time, length of stay in intensive care unit and hospital, postoperative adverse events and mortality rates were not different between the groups. Conclusion: Despite higher cytokine and lactate levels and alveolar-arterial oxygen gradients in specific time periods, an attenuation in the inflammatory response following cardiopulmonary bypass due to low-frequency, low-tidal volume ventilation could not be documented. Clinical parameters concerning pulmonary and other major system functions and occurrence of postoperative adverse events were not affected by continuous ventilation.
The Journal of Thoracic and Cardiovascular Surgery, 2005
Objectives: Respiratory support for patients recovering from cardiopulmonary bypass and cardiac surgery uses large tidal volumes and a minimal level of positive end-expiratory pressure. Recent data indicate that these ventilator settings might cause pulmonary and systemic inflammation in patients with acute lung injury. We examined the hypothesis that high tidal volumes and low levels of positive endexpiratory pressure might worsen the inflammatory response associated to cardiopulmonary bypass. Methods: Forty patients undergoing elective coronary artery bypass were randomized to be ventilated after cardiopulmonary bypass disconnection with high tidal volume/low positive end-expiratory pressure (10-12 mL/kg and 2-3 cm H 2 O, respectively) or low tidal volume/high positive end-expiratory pressure (8 mL/kg and 10 cm H 2 O, respectively). Interleukin 6 and interleukin 8 levels were measured in the bronchoalveolar lavage fluid and plasma. Samples were taken before sternotomy (time 0), immediately after cardiopulmonary bypass separation (time 1), and after 6 hours of mechanical ventilation (time 2). Results: Interleukin 6 and interleukin 8 levels in the bronchoalveolar lavage fluid and plasma significantly increased at time 1 in both groups but further increased at time 2 only in patients ventilated with high tidal volume/low positive end-expiratory pressure. Interleukin 6 and interleukin 8 levels in the bronchoalveolar lavage fluid and in the plasma at time 2 were higher with high tidal volume/low positive end-expiratory pressure than with low tidal volume/high positive end-expiratory pressure. Conclusion: Mechanical ventilation might be a cofactor able to influence the inflammatory response after cardiac surgery.
European Journal of Cardio-Thoracic Surgery, 2005
Objective: Cardiac surgery with cardiopulmonary bypass (CPB) is associated with a systemic inflammatory response, which is correlated with outcome. We hypothesized that ventilation according to the open lung concept (OLC) attenuates cytokine release. Methods: A prospective, single center randomized controlled clinical study containing 62 patients scheduled for elective coronary artery bypass graft and/or valve surgery with cardiopulmonary bypass. Before surgery, patients were randomly assigned to three groups: (1) conventional mechanical ventilation (CV), (2) OLC started after arrival on the ICU (late open lung, LOL), and (3) OLC started directly after intubation (early open lung, EOL). In both OLC groups, recruitment maneuvers were applied until PaO 2 /FiO 2 > 50. The CV group received no recruitment maneuvers. Interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor (TNF)-a, and interferon (IFN)-g were measured preoperatively, immediately after cessation of CPB, and 3 h, 5 h, 24 h, 2, and 3 days after cessation of CPB. Results: CPB caused a significant increase of IL-6, IL-8, and IL-10 in all groups. Thereafter, IL-8 decreased significantly more rapidly in both OLC groups compared to CV. IL-10 decreased significantly more rapidly after CPB only in the EOL group, compared with CV. Three hours after cessation of the CPB, IL-10 was already comparable with preoperative levels in the EOL group, but not in the LOL or CV group. IL-6, TNF-a, and IFN-g did not differ significantly between groups. Conclusions: OLC ventilation leads to an attenuated inflammatory response, presumably by reducing additional lung injury after cardiac surgery. Studies on cytokines after cardiac surgery should take these findings into account. #
The Impact of Lung Ventilation on Some Cytokines after Coronary Artery Bypass Grafting
Scandinavian Journal of Surgery, 2016
Background and Aims: cardiopulmonary bypass induces a systematic inflammatory response, which is partly understood by investigation of peripheral blood cytokine levels alone; the lungs may interfere with the net cytokine concentration. We investigated whether lung ventilation influences lung passage of some cytokines after coronary artery bypass grafting. Material and Methods: In total, 47 patients undergoing coronary artery bypass grafting were enrolled, and 37 were randomized according to the ventilation technique: (1) noventilation group, with intubation tube detached from the ventilator; (2) low tidal volume group, with continuous low tidal volume ventilation; and (3) continuous 10 cm h 2 o positive airway pressure. Ten selected patients undergoing surgery without cardiopulmonary bypass served as a referral group. representative pulmonary and radial artery blood samples were collected for the evaluation of calculated lung passage (pulmonary/radial artery) of the pro-inflammatory cytokines (interleukin 6 and interleukin 8) and the antiinflammatory interleukin 10 immediately after induction of anesthesia (T1), 1 h after restoring ventilation/return of flow in all grafts (T2), and 20 h after restoring ventilation/ return of flow in all grafts (T3). Results: pulmonary/radial artery interleukin 6 and pulmonary/radial artery interleukin 8 ratios (p = 0.001 and p = 0.05, respectively) decreased, while pulmonary/radial artery interleukin 10 ratio (p = 0.001) increased in patients without cardiopulmonary bypass as compared with patients with cardiopulmonary bypass.
Zanjan University of Medical Sciences, Zanjan, Iran, 2022
Background & Objective: The present study aimed to assess the supportive role of open lung ventilation on respiratory mechanics, the rate of oxygenation, inflammatory biomarkers, and probable liver or renal injuries following coronary artery bypass grafting surgery. Materials & Methods: This randomized double-blinded clinical trial study was conducted on 64 candidates for coronary artery bypass surgery using a cardiopulmonary pump. The patients were randomly categorized into the Positive endexpiratory pressure (PEEP) group (n = 32) or Zero End Expiratory Pressure (ZEEP) group (n = 32). Results: Interleukin-6 levels were similar between the PEEP and ZEEP groups before surgery (p = 0.18) and were significantly higher in the ZEEP group after pump insertion (p = 0.005). On the contrary, the levels of Interleukin-6 were significantly higher in the PEEP group after extubation (p = 0.001). The Between-group analysis also showed a significant difference between the levels of interleukin-6 in the ZEEP and PEEP groups, representing a greater increase in the PEEP group (p < 0.001). There was no difference in certain hemodynamic parameters, including heart rate, mean blood pressure, mean CO2 pressure (PCO2), mean concentration of HCO3, and base excess. The mean arterial O2 saturation was higher overall in the PEEP group compared to the ZEEP group. The mean PaO2/FiO2 was significantly higher in the PEEP than in the ZEEP group (p < 0.001). Conclusion: Supportive ventilation technique leads to better oxygenation and better lung expansion, as well as lowering inflammatory biomarkers, after coronary artery bypass surgery.
Intensive Care Medicine, 2005
Objective: To examine whether postoperative mechanical ventilation with lower tidal volumes (V T ) has protective effects on inflammatory responses induced by cardiopulmonary bypass (CPB) surgery in smokers and nonsmokers. Design and setting: Prospective, randomized, controlled clinical trial in the intensive care unit of a university hospital. Patients and participants: We examined 44 patients (22 smokers, 22 nonsmokers) immediately after uncomplicated CPB surgery. Interventions: Ventilation was applied for 6 h with either V T of either 6 or 12 ml/kg ideal body weight. Measurements and results: The time course of serum tumor necrosis factor (TNF) a, interleukin (IL) 6, and IL-8 determined 0, 2, 4, and 6 h after randomization did not differ significantly between the ventilatory strategies. By contrast, in bronchoalveolar lavage fluids sampled after 6 h only TNF-a levels were significantly higher in the high V T group than the low V T group (50€111 pg/ml vs. 1€7 pg/ml). IL-6 and IL-8 concentrations did not differ between groups. Subgroup analysis of patients with serum TNF-a level higher than 0 pg/ml after surgery revealed lower TNF-a serum levels during lower V T ventilation. All observed effects were small, independent of patients' history of smoking, and were not correlated with duration of ventilation and ICU stay. Conclusions: Ventilation with lower V T had no or only minor effect on systemic and pulmonary inflammatory responses in patients with healthy lungs after uncomplicated CPB surgery. Our data do not suggest a clinical benefit of using low V T ventilation in these selected patients.
Journal of Advances in Medical and Biomedical Research, 2022
1. Dept. of Anesthesiology, Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran 2. Dept. of Anesthesiology, Firoozgar Hospital, Iran University of Medical Sciences, Tehran, Iran 3. Exceptional Talent Development Center (EDTC), Tehran University of Medical Sciences, Tehran, Iran 4. Dept. of Anesthesiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. 5. Hasheminejad Kidney Center (HKC), Iran University of Medical Sciences, Tehran, Iran.