762
LETTERS TO THE EDITOR
administration into preidentified atelectatic segments, as we did in our case, in contrast to the administration into the whole lungs, including areas without any need for increased surfactant concentration. Albrecht Wiebalck, MD Stephan Schulz, MD Michael Zenz, MD, PhD Klinik fu¨r Anaesthesiologie Intensiv- und Schmerztherapie Universita¨tskliniken Bergmannsheil Bochum, Germany Adrian Gillissen, MD, PhD Department of Internal Medicine II Division of Pneumology University of Bonn Bonn, Germany REFERENCES 1. Schulz S, Wiebalck A, Frankenberg C, et al: Low-dose surfactant instillation during extracorporeal membrane oxygenation in a patient with adult respiratory distress syndrome and secondary atelectasis after chest contusion. J Cardiothorac Vasc Anesth 14:59-62, 2000 2. Spragg R, Gilliard N, Richman P, et al: Acute effects of a single dose of porcine surfactant on patients with the adult respiratory distress syndrome. Chest 105:195-202, 1994 3. Weg JG, Balk RA, Tharratt RS, et al, for the Exosurf ARDS Sepsis Study Group: Safety and potential efficacy of an aerosolized surfactant in human sepsis-induced adult respiratory distress syndrome. JAMA 272:1433-1438, 1994 4. Walmrath D, Gu¨nther A, Ghofrani HA, et al: Bronchoscopic surfactant administration in patients with severe adult respiratory dis-
tress syndrome (ARDS) and sepsis. Am J Respir Crit Care Med 154:57-62, 1996 5. Pearson GA, Field DJ, Firmin RK, Sosnowski AS: UK experience in neonatal extracorporeal membrane oxygenation. Arch Dis Child 67:822-825, 1992 (7 spec no) 6. Morris AH, Wallace CJ, Menlove RL, et al: Randomized clinical trial of pressure-controlled inverse ratio ventilation and extracorporeal CO2 removal for adult respiratory distress syndrome. Am J Respir Crit Care Med 149:295-305, 1994 (2 pt 1) 7. Greenspan JS, Wolfson MR, Rubenstein SD, Shaffer TH: Liquid ventilation of human preterm neonates. J Pediatr 117:106-111, 1990 doi: 10.1053/jcan.2000.18675
Off-Pump Coronary Artery Bypass in Underdeveloped Countries To the Editor: Several authors have described a surgical technique that minimizes the sequelae of conventional coronary artery bypass graft (CABG) surgery by avoiding cardiopulmonary bypass (CPB).1-5 At Abbott Northwestern Hospital (Minneapolis, MN) we currently perform ⬎60% of CABG operations using a midsternotomy approach, performed on the beating heart while avoiding CPB and cardioplegia. The absence of the use of CPB, with its neurologic effects, hypothermia, electrolyte abnormalities, and anemia, makes early extubation attainable and desirable, promoting prompt patient ambulation and discharge. Physicians, nurses, and technicians from our institution visited East Africa as team members from Children’s HeartLink (CHL), a 30-year-old international organization in the private sector providing cardiac care to children and adults. CHL contributes to the public health in developing countries by providing at each site long-term commitment to medical education and training, improving access to quality health care to underserved families in poverty, and providing regional treatment centers for patients with serious heart disease. Our commitment to Kenya began 7 years ago with our training and education of an all-Kenyan team consisting of a cardiac surgeon, anesthesiologist, nurses, and technicians. Since then, the CHL team has made 3 on-site visits to the Nairobi Hospital, teaching skills of increasing complexity to our Kenyan counterparts. The ultimate goal of our continuing medical education is to assist each site to become self-sufficient. On 2 previous visits, our team concentrated on conventional CABG surgery using extracorporeal circulation. In December 1999, we assisted the Kenyan team in performing off-pump CABG procedures on 2 patients with demonstrated coronary artery stenosis by angiogram. Multiple bypass grafts were performed on each patient using internal mammary artery and saphenous vein grafts. A CPB machine and team of perfusionists were on stand-by. Hemodynamic monitoring consisted of an arterial catheter, central venous pressure catheter, and simultaneous 5-lead precordial electrocardiogram. Many authors contend that off-pump CABG surgery can save health care dollars through the avoidance of CPB, less use of blood products, and shorted intensive care unit stays.1,2,5,7 Definitive studies are needed to show unequivocal evidence for this contention. In Kenya, most of our equipment, including pulse oximetry (Nonin Medical, Eden Prairie, MN), Octopus II coronary artery
LETTERS TO THE EDITOR
763
stabilizers (Medtronic Corporation, Minneapolis, MN), and Bair Hugger thermoregulation (Augustine Medical, Eden Prairie, MN) was donated, minimizing expenditures. Additionally, our patients were extubated in the operating room and discharged from the intensive care unit ⬍24 hours after admission. Both of our patients returned to their respective villages without postoperative complications within 5 days of surgery. When compared with the United States, some so-called “less-developed” countries have a greater experience in off-pump CABG surgery. In a large series from Turkey, for example, Tasdemier and Viral6 performed ⬎2000 off-pump CABG procedures and reported lower costs and little use of blood or blood products in ⬎75% of the patients. In a 1300-patient study in Brazil, Buffolo7 reported fewer neurological deficits and decreased overall costs associated with the OP-CABG technique. Previously, all coronary artery surgical candidates from East Africa were transported to England, India, or South African for their surgical procedures. It is our experience and continued expectation that through our long-term commitment and follow-up education and training, the Kenyan project will provide East Africans a local and less expensive alternative for cardiac care. Our Nairobi relationship shows that a committed international cardiac care organization can successfully train local medical teams in underdeveloped countries to perform cutting-edge cardiac surgical and anesthetic techniques. James M. Gayes, MD Department of Anesthesiology Abbott Northwestern Hospital Minneapolis, MN 55404 REFERENCES 1. Arom K, Flavin T, Emery R, et al: Safety and efficacy of offpump coronary artery bypass grafting. Ann Thorac Surg 29:704-710, 2000 2. Emery RW, Arom KV: Minimally invasive coronary artery bypass surgery: State of the art. Adv Card Surg 10:177-189, 1999 3. Jasnsen EW, Borst C, et al: Coronary artery bypass grafting without cardiopulmonary bypass using the octopus method. J Thorac Cardiovasc Surg 116:60-67, 1998 4. Diegeler A, Matin M, et al: Coronary bypass grafting without cardiopulmonary bypass—technical considerations clinical results, and follow-up. J Thorac Cardiovasc Surg 47:14-18, 1999
5. Puskas JD: Off-pump multivessel coronary artery bypass is safe and effective. Ann Thorac Cardiovasc Surg 66:1068-1072, 1998 6. Tasdemier O, Vural KM: Coronary artery bypass grafting without the use of extracorporeal circulation: Review of 2052 cases. J Thorac Cardiovasc Surg 116:68-73, 1998 7. Buffolo E: Coronary artery bypass grafting without cardiopulmonary bypass. Ann Thorac Surg 61:63-66, 1996
doi: 10.1053/jcan.2000.18676
Vasopressor Infusion During Off-Pump Coronary Artery Bypass Graft Surgery To the Editor: Extracorporeal circulation is no longer seen as an obligatory sacrifice for coronary artery revascularization as in the past. The advantages of off-pump coronary artery bypass graft (CABG) surgeries most commonly reported are decreased operative mortality, improved perioperative outcome, reduced perioperative myocardial infarction incidence, and shorter hospital stay.1-9 Avoiding the use of cardiopulmonary bypass can prevent the severe inflammatory response and systemic release of microthrombi, which adversely affect the patient’s coagulation system and cognitive performance.4,5 Off-pump CABG procedures are becoming popular.1,2,3,7 At our center from December 1996 to February 2000, we performed 838 off-pump procedures. Monitoring during revascularization consists of ST-segment analysis (lead II and modified chest leads on Omnicare anesthesia monitoring system, HP model 665; Hewlett Packard, Andover, MA), direct arterial blood pressure, pulmonary artery pressure and cardiac output monitoring by pulmonary artery catheter, urine output, temperature, oxygen saturation by pulse oximetry, end-tidal carbon dioxide, end-tidal isoflurane, and online transesophageal echocardiography. No major changes in hemodynamics have been seen during left anterior descending artery revascularization, but there is often a significant decrease in arterial pressures and cardiac output when circumflex and right coronary artery grafting is done. This decrease is mostly due to retraction, lifting, and compression of the heart either manually by the assistant’s hand or by the mechanical stabilizer. Hypotension during this period can jeopardize the already ischemic myocardium, made worse by proximal occlusion of the target vessel. To overcome this problem, we initially infused volume (usually a crystalloid) or administered boluses of vasopressor (ephedrine, 6 mg/mL, or norepinephrine, 2 mg diluted in 250 mL of normal saline) until desirable pressures (at least 80 mmHg of systolic) were achieved. As our experience increased, we started treating more and more patients for whom cardiopulmonary bypass was contraindicated (ie, mobile atheroma, chronic renal failure, carotid artery disease).4,5 Because these cases required a higher perfusion pressure, we