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LETTERS TO THE EDITOR
8. Hilbert G, Clouzeau B, Nam Bui H, et al: Sedation during noninvasive ventilation. Minerva Anestesiol 78:842-846, 2012 9. García-Delgado M, Navarrete I, García-Palma MJ, et al: Postoperative respiratory failure after cardiac surgery: Use of noninvasive ventilation. J Cardiothorac Vasc Anesth 26:443-447, 2012 10. Chiumello D, Chevallard G, Gregoretti C: Non-invasive ventilation in postoperative patients: A systematic review. Intensive Care Med 37:918-929, 2011 11. Esquinas Rodriguez AM, Papadakos PJ, Carron M, et al: Clinical review: Helmet and non-invasive mechanical ventilation in critically ill patients. Crit Care 17:223, 2013 12. Redondo Calvo FJ, Madrazo M, Gilsanz F, et al: Helmet noninvasive mechanical ventilation in patients with acute postoperative respiratory failure. Respir Care 57:743-752, 2012 13. Cabrini L, Nobile L, Cama E, et al: Non-invasive ventilation during upper endoscopies in adult patients. A systematic review. Minerva Anestesiol 79:683-694, 2013 14. Antonelli M, Pennisi MA, Conti G, et al: Fiberoptic bronchoscopy during noninvasive positive pressure ventilation delivered by helmet. Intensive Care Med 29:126-129, 2003 http://dx.doi.org/10.1053/j.jvca.2013.08.007
Robotic Myocardial Revascularization Increases Morbidity and Mortality? To the Editor: We read with great interest the recent Pro and Con section of the Journal regarding robotic coronary artery bypass grafting.1,2 We would like to call your attention to a recently published study from our institution that sheds additional light on this topic and was not referenced by either side.3 Our results suggest that addressing multivessel coronary artery disease using total edoscopic coronary artery bypass offers no obvious clinical benefits and might increase morbidity and mortality. Our retrospective clinical investigation reviewed 106 patients undergoing total endoscopic coronary artery bypass (72% multivessel) at our institution (July 2007–February 2009) by one experienced cardiac surgeon/physician assistant team. These results were compared with the expected clinical outcomes from conventional coronary artery bypass grafting calculated using the Society of Thoracic Surgeons risk calculator. Of the 106 patients, 1% underwent quadruple total endoscopic coronary artery bypass, 8% triple, 63% double, and 28% single. Four patients underwent elective intraoperative conversion by way of a thoracotomy (not considered morbidity). The emergent conversion rate for hemodynamic instability was 6.6% (7 patients). Of these seven, 5 required sternotomy (2 intraoperative, 3 requiring a return to the operating room) and 2 required thoracotomy (both intraoperative). Initiation of cardiopulmonary bypass was required in 3 patients (2 emergent via median sternotomy). The one elective initiation of cardiopulmonary bypass (closed chest) was required for hemodynamic instability (patient also experienced postoperative stroke). The postoperative renal failure rate (doubling of baseline serum creatinine or dialysis required) was 7.5%. Overall, 39 patients (36.8%) experienced morbidity or
mortality, of which 23 patients (21.7%) exhibited at least one major morbidity/mortality (4 deaths). The number of vessels bypassed (single/double/triple/quadruple) correlated positively with the surgical/operating room time, the lung separation time, vasoactive medication use, blood use, a postoperative ventilation time longer than 24 hours, intensive care unit length of stay, and hospital length of stay. An increased surgical time was significantly associated with major morbidity (p ¼ 0.011) and mortality (p ¼ 0.043). A comparison with the Society for Thoracic Surgeons expected outcomes revealed a similar hospital length of stay but an increased incidence of prolonged ventilation (p ¼ 0.003), renal failure (p o 0.001), morbidity (p ¼ 0.045), and mortality (p ¼ 0.049). Lastly, a decrease in major morbidity/mortality rate over time (ie, with more experience) was not statistically significant. The rate was 35% among the first 26 patients, 19% among the next 27 patients, 22% among the next 27 patients, and 12% among the last 26 patients (Cochran-Armitage trend test, p ¼ 0.71). Intraoperative hemodynamic instability is a challenging clinical reality of this technique. Carbon dioxide insufflation (essentially a pneumothorax) leads to cardiac displacement and decreased venous return, when coupled with potential hypoxemia/hypercarbia (prolonged single-lung ventilation), might lead to increased central venous pressure, increased pulmonary artery pressure, decreased cardiac output, and hypotension. Right ventricular dysfunction (single-lung ventilation-initiated atelectasis, hypoxic vasoconstriction) and/or left ventricular dysfunction (compliance changes) might also contribute. Such hemodynamic instability necessitates preload augmentation and/or use of inotropes/vasoconstrictors. We hypothesize that increasing the number of vessels bypassed (thus, increasing single-lung ventilation time/surgical time) promotes greater hemodynamic instability (increasing vasoactive medication use) and might be the underlying etiology of the increased morbidity and mortality observed in our investigation. Because of this procedure-induced hemodynamic instability, many have recommended robotic myocardial revascularization only for single-vessel disease in patients with reasonable cardiopulmonary reserve.
Mark A. Chaney, MD J. Devin Roberts, MD Department of Anesthesia and Critical Care University of Chicago Medical Center Chicago, IL REFERENCES 1. Deshpande SP, Fitzpatrick M, Grigore AM: Pro: Robotic surgery is the preferred technique for coronary artery bypass graft (CABG) surgery. J Cardiothorac Vasc Anesth 27:802-805, 2013 2. Raiten JM: Con: Robotic surgery is not the preferred technique for coronary revascularization. J Cardiothorac Vasc Anesth 27:806-808, 2013 3. Dhawan R, Roberts JD, Wroblewski K, et al: Multivessel beating heart robotic myocardial revascularization increases morbidity and mortality. J Thorac Cardiovasc Surg 143:1056-1061, 2012 http://dx.doi.org/10.1053/j.jvca.2013.08.016
LETTERS TO THE EDITOR
8. Hilbert G, Clouzeau B, Nam Bui H, et al: Sedation during noninvasive ventilation. Minerva Anestesiol 78:842-846, 2012 9. García-Delgado M, Navarrete I, García-Palma MJ, et al: Postoperative respiratory failure after cardiac surgery: Use of noninvasive ventilation. J Cardiothorac Vasc Anesth 26:443-447, 2012 10. Chiumello D, Chevallard G, Gregoretti C: Non-invasive ventilation in postoperative patients: A systematic review. Intensive Care Med 37:918-929, 2011 11. Esquinas Rodriguez AM, Papadakos PJ, Carron M, et al: Clinical review: Helmet and non-invasive mechanical ventilation in critically ill patients. Crit Care 17:223, 2013 12. Redondo Calvo FJ, Madrazo M, Gilsanz F, et al: Helmet noninvasive mechanical ventilation in patients with acute postoperative respiratory failure. Respir Care 57:743-752, 2012 13. Cabrini L, Nobile L, Cama E, et al: Non-invasive ventilation during upper endoscopies in adult patients. A systematic review. Minerva Anestesiol 79:683-694, 2013 14. Antonelli M, Pennisi MA, Conti G, et al: Fiberoptic bronchoscopy during noninvasive positive pressure ventilation delivered by helmet. Intensive Care Med 29:126-129, 2003 http://dx.doi.org/10.1053/j.jvca.2013.08.007
Robotic Myocardial Revascularization Increases Morbidity and Mortality? To the Editor: We read with great interest the recent Pro and Con section of the Journal regarding robotic coronary artery bypass grafting.1,2 We would like to call your attention to a recently published study from our institution that sheds additional light on this topic and was not referenced by either side.3 Our results suggest that addressing multivessel coronary artery disease using total edoscopic coronary artery bypass offers no obvious clinical benefits and might increase morbidity and mortality. Our retrospective clinical investigation reviewed 106 patients undergoing total endoscopic coronary artery bypass (72% multivessel) at our institution (July 2007–February 2009) by one experienced cardiac surgeon/physician assistant team. These results were compared with the expected clinical outcomes from conventional coronary artery bypass grafting calculated using the Society of Thoracic Surgeons risk calculator. Of the 106 patients, 1% underwent quadruple total endoscopic coronary artery bypass, 8% triple, 63% double, and 28% single. Four patients underwent elective intraoperative conversion by way of a thoracotomy (not considered morbidity). The emergent conversion rate for hemodynamic instability was 6.6% (7 patients). Of these seven, 5 required sternotomy (2 intraoperative, 3 requiring a return to the operating room) and 2 required thoracotomy (both intraoperative). Initiation of cardiopulmonary bypass was required in 3 patients (2 emergent via median sternotomy). The one elective initiation of cardiopulmonary bypass (closed chest) was required for hemodynamic instability (patient also experienced postoperative stroke). The postoperative renal failure rate (doubling of baseline serum creatinine or dialysis required) was 7.5%. Overall, 39 patients (36.8%) experienced morbidity or
mortality, of which 23 patients (21.7%) exhibited at least one major morbidity/mortality (4 deaths). The number of vessels bypassed (single/double/triple/quadruple) correlated positively with the surgical/operating room time, the lung separation time, vasoactive medication use, blood use, a postoperative ventilation time longer than 24 hours, intensive care unit length of stay, and hospital length of stay. An increased surgical time was significantly associated with major morbidity (p ¼ 0.011) and mortality (p ¼ 0.043). A comparison with the Society for Thoracic Surgeons expected outcomes revealed a similar hospital length of stay but an increased incidence of prolonged ventilation (p ¼ 0.003), renal failure (p o 0.001), morbidity (p ¼ 0.045), and mortality (p ¼ 0.049). Lastly, a decrease in major morbidity/mortality rate over time (ie, with more experience) was not statistically significant. The rate was 35% among the first 26 patients, 19% among the next 27 patients, 22% among the next 27 patients, and 12% among the last 26 patients (Cochran-Armitage trend test, p ¼ 0.71). Intraoperative hemodynamic instability is a challenging clinical reality of this technique. Carbon dioxide insufflation (essentially a pneumothorax) leads to cardiac displacement and decreased venous return, when coupled with potential hypoxemia/hypercarbia (prolonged single-lung ventilation), might lead to increased central venous pressure, increased pulmonary artery pressure, decreased cardiac output, and hypotension. Right ventricular dysfunction (single-lung ventilation-initiated atelectasis, hypoxic vasoconstriction) and/or left ventricular dysfunction (compliance changes) might also contribute. Such hemodynamic instability necessitates preload augmentation and/or use of inotropes/vasoconstrictors. We hypothesize that increasing the number of vessels bypassed (thus, increasing single-lung ventilation time/surgical time) promotes greater hemodynamic instability (increasing vasoactive medication use) and might be the underlying etiology of the increased morbidity and mortality observed in our investigation. Because of this procedure-induced hemodynamic instability, many have recommended robotic myocardial revascularization only for single-vessel disease in patients with reasonable cardiopulmonary reserve.
Mark A. Chaney, MD J. Devin Roberts, MD Department of Anesthesia and Critical Care University of Chicago Medical Center Chicago, IL REFERENCES 1. Deshpande SP, Fitzpatrick M, Grigore AM: Pro: Robotic surgery is the preferred technique for coronary artery bypass graft (CABG) surgery. J Cardiothorac Vasc Anesth 27:802-805, 2013 2. Raiten JM: Con: Robotic surgery is not the preferred technique for coronary revascularization. J Cardiothorac Vasc Anesth 27:806-808, 2013 3. Dhawan R, Roberts JD, Wroblewski K, et al: Multivessel beating heart robotic myocardial revascularization increases morbidity and mortality. J Thorac Cardiovasc Surg 143:1056-1061, 2012 http://dx.doi.org/10.1053/j.jvca.2013.08.016
