Risto Kesävuori1,2, Antti Vento1, Nina Lundbom2, Alexey Schramko3, Janne J Jokinen4, Peter Raivio1. 1. Department of Cardiac Surgery, Heart and Lung Center, Helsinki University Hospital, Helsinki, Finland. 2. Department of Radiology, HUS Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland. 3. Department of Anaesthesiology, Intensive Care and Pain Medicine, Helsinki University Hospital, Helsinki, Finland. 4. Department of Surgery, Päijät-Häme Central Hospital, Lahti, Finland.
Abstract
INTRODUCTION: A minimal volume ventilation method for robotically assisted mitral valve surgery is described in this study. In an attempt to reduce postoperative pulmonary dysfunction, 40 of 174 patients undergoing robotically assisted mitral valve surgery were ventilated with a small tidal volume during cardiopulmonary bypass. METHODS: After propensity score matching, 31 patients with minimal volume ventilation were compared with 54 patients with no ventilation. Total ventilation time, PaO2/FiO2 ratio, arterial lactate concentration, and the rate of unilateral pulmonary edema in the matched minimal ventilation and standard treatment groups were evaluated. RESULTS: Patients in the minimal ventilation group had shorter ventilation times, 12.0 (interquartile range: 9.9-15.0) versus 14.0 (interquartile range: 12.0-16.3) hours (p = 0.036), and lower postoperative arterial lactate levels, 0.99 (interquartile range: 0.81-1.39) versus 1.28 (interquartile range: 0.99-1.86) mmol/L (p = 0.01), in comparison to patients in the standard treatment group. There was no difference in postoperative PaO2/FiO2 ratio levels or in the rate of unilateral pulmonary edema between the groups. CONCLUSION: Minimal ventilation appeared beneficial in terms of total ventilation time and blood lactatemia, while there was no improvement in arterial blood gas measurements or in the rate of unilateral pulmonary edema. The lower postoperative arterial lactate levels may suggest improved lung perfusion among patients in the minimal volume ventilation group. The differences in the ventilation times were in fact small, and further studies are required to confirm the possible advantages of the minimal volume ventilation method in robotically assisted cardiac surgery.
INTRODUCTION: A minimal volume ventilation method for robotically assisted mitral valve surgery is described in this study. In an attempt to reduce postoperative pulmonary dysfunction, 40 of 174 patients undergoing robotically assisted mitral valve surgery were ventilated with a small tidal volume during cardiopulmonary bypass. METHODS: After propensity score matching, 31 patients with minimal volume ventilation were compared with 54 patients with no ventilation. Total ventilation time, PaO2/FiO2 ratio, arterial lactate concentration, and the rate of unilateral pulmonary edema in the matched minimal ventilation and standard treatment groups were evaluated. RESULTS:Patients in the minimal ventilation group had shorter ventilation times, 12.0 (interquartile range: 9.9-15.0) versus 14.0 (interquartile range: 12.0-16.3) hours (p = 0.036), and lower postoperative arterial lactate levels, 0.99 (interquartile range: 0.81-1.39) versus 1.28 (interquartile range: 0.99-1.86) mmol/L (p = 0.01), in comparison to patients in the standard treatment group. There was no difference in postoperative PaO2/FiO2 ratio levels or in the rate of unilateral pulmonary edema between the groups. CONCLUSION: Minimal ventilation appeared beneficial in terms of total ventilation time and blood lactatemia, while there was no improvement in arterial blood gas measurements or in the rate of unilateral pulmonary edema. The lower postoperative arterial lactate levels may suggest improved lung perfusion among patients in the minimal volume ventilation group. The differences in the ventilation times were in fact small, and further studies are required to confirm the possible advantages of the minimal volume ventilation method in robotically assisted cardiac surgery.