Perioperative determinants of morbidity and mortality in elderly patients undergoing cardiac surgery*

ObjectiveTo determine perioperative predictors of morbidity and mortality in patients ≥75 yrs of age after cardiac surgery. DesignInception cohort study. SettingA tertiary care, 54-bed cardiothoracic intensive care unit (ICU). PatientsAll patients aged ≥75 yrs admitted over a 30-month period for cardiac surgery. InterventionCollection of data on preoperative factors, operative factors, postoperative hemodynamics, and laboratory data obtained on admission and during the ICU stay. Measurements and Main ResultsPostoperative death, frequency rate of organ dysfunction, nosocomial infections, length of mechanical ventilation, and ICU stay were recorded. During the study period, 1,157 (14%) of 8,501 patients ≥75 yrs of age had a morbidity rate of 54% (625 of 1,157 patients) and a mortality rate of 8% (90 of 1,157 patients) after cardiac surgery. Predictors of postoperative morbidity included preoperative intraaortic balloon counterpulsation, preoperative serum bilirubin of >1.0 mg/dL, blood transfusion requirement of >10 units of red blood cells, cardiopulmonary bypass time of >120 mins (aortic cross-clamp time of >80 mins), return to operating room for surgical exploration, heart rate of >120 beats/min, requirement for inotropes and vasopressors after surgery and on admission to the ICU, and anemia beyond the second postoperative day. Predictors of postoperative mortality included preoperative cardiac shock, serum albumin of <4.0 g/dL, systemic oxygen delivery of <320 mL/min/m2 before surgery, blood transfusion requirement of >10 units of red blood cells, cardiopulmonary bypass time of >140 mins (aortic cross-clamp time of >120 mins), subsequent return to the operating room for surgical exploration, mean arterial pressure of <60 mm Hg, heart rate of >120 beats/min, central venous pressure of >15 mm Hg, stroke volume index of <30 mL/min/m2, requirement for inotropes, arterial bicarbonate of <20 mmol/L, plasma glucose of >300 mg/dL after surgery, and anemia beyond the second postoperative day. During the study period, the study cohort used 6,859 (21.5%) ICU patient-days out of a total 31,867 ICU patient-days. Nonsurvivors used 2,023 (30%) ICU patient-days and patients with morbidity used 5,903 (86%) ICU patient-days. ConclusionsSevere underlying cardiac disease (including shock, requirement for mechanical circulatory support, hypoalbuminemia, and hepatic dysfunction), intraoperative blood loss, surgical reexploration, long ischemic times, immediate postoperative cardiovascular dysfunction, global ischemia and metabolic dysfunction, and anemia beyond the second postoperative day predicted poor outcome in the elderly after cardiac surgery. Postoperative morbidity and mortality disproportionately increased the utilization of intensive care resources in elderly patients. Future efforts should focus on preoperative selection criteria, improvement in surgical techniques, perioperative therapy to ameliorate splanchnic and global ischemia, and avoidance of anemia to improve the outcome in the elderly after cardiac surgery. (Crit Care Med 1998; 26:225–235)

[1]  D. McClish,et al.  The Impact of Age on Utilization of Intensive Care Resources , 1987, Journal of the American Geriatrics Society.

[2]  J. Rowe,et al.  Academic geriatrics for the year 2000. An Institute of Medicine report. , 1987, New England Journal of Medicine.

[3]  Arthur S Slutsky,et al.  Transfusion requirements in critical care : a pilot study , 1995 .

[4]  R. McCarthy,et al.  Morbidity and duration of ICU stay after cardiac surgery. A model for preoperative risk assessment. , 1992, Chest.

[5]  Allen J. Taylor,et al.  Current status of coronary artery operation in septuagenarians. , 1991, The Annals of thoracic surgery.

[6]  B. Chernow,et al.  The use and clinical importance of a substrate-specific electrode for rapid determination of blood lactate concentrations. , 1994, JAMA.

[7]  A. Webb,et al.  Perioperative plasma volume expansion reduces the incidence of gut mucosal hypoperfusion during cardiac surgery. , 1995, Archives of surgery.

[8]  R. Kronmal,et al.  Coronary Arteriography and Coronary Artery Bypass Surgery: Morbidity and Mortality in Patients Ages 65 Years or Older A Report from the Coronary Artery Surgery Study , 1983, Circulation.

[9]  H. Schaff,et al.  Cardiac surgery in the octogenarian: perioperative outcome and clinical follow-up. , 1991, Journal of the American College of Cardiology.

[10]  J. Bion,et al.  Intestinal permeability, gastric intramucosal pH, and systemic endotoxemia in patients undergoing cardiopulmonary bypass. , 1996, JAMA.

[11]  L. Landow.  Splanchnic lactate production in cardiac surgery patients , 1993, Critical care medicine.

[12]  P. Gunter.  Practice Guidelines for Blood Component Therapy , 1996 .

[13]  G. Beck,et al.  Stratification of morbidity and mortality outcome by preoperative risk factors in coronary artery bypass patients. A clinical severity score. , 1992, JAMA.

[14]  LG Martin.  Population aging policies in East Asia and the United States , 1991, Science.

[15]  L. Cohn,et al.  Favorable results of coronary artery bypass grafting in patients older than 75 years. , 1990, The Journal of thoracic and cardiovascular surgery.

[16]  G. Hall,et al.  Effect of high-dose fentanyl anaesthesia on the metabolic and endocrine response to cardiac surgery. , 1981, British journal of anaesthesia.

[17]  P. Levy,et al.  Acute dilutional anemia and critical left anterior descending coronary artery stenosis impairs end organ oxygen delivery. , 1996, The Journal of trauma.

[18]  I. L. Cohen,et al.  Mechanical ventilation for the elderly patient in intensive care : incremental charges and benefits , 1993 .

[19]  M. Frass,et al.  Influence of age on outcome of mechanically ventilated patients in an intensive care unit , 1992, Critical care medicine.

[20]  R. Oye,et al.  Predictors of Mortality in Older Patients following Medical Intensive Care: The Importance of Functional Status , 1991, Journal of the American Geriatrics Society.

[21]  J. Rowe,et al.  Academic geriatrics for the year 2000. , 1987, The New England journal of medicine.

[22]  R. Pifarré.  Open heart operations in the elderly: changing risk parameters. , 1993, The Annals of thoracic surgery.

[23]  K. Inman,et al.  Hyperdynamic sepsis depresses circulatory compensation to normovolemic anemia in conscious rats. , 1996, Journal of applied physiology.

[24]  T. Treasure,et al.  Which patients will not benefit from further intensive care after cardiac surgery? , 1994, The Lancet.

[25]  Andrew D. Rosenberg,et al.  Practice Guidelines for Blood Component Therapy: A Report by the American Society of Anesthesiologists Task Force on Blood Component Therapy , 1996, Anesthesiology.

[26]  L. Casey.  Role of cytokines in the pathogenesis of cardiopulmonary-induced multisystem organ failure. , 1993, The Annals of thoracic surgery.

[27]  E. Schmid,et al.  Hemodilution Tolerance in Patients with Coronary Artery Disease Who Are Receiving Chronic beta-Adrenergic Blocker Therapy , 1996, Anesthesia and analgesia.

[28]  W. Simpson,et al.  Correlation of serum cytokine and acute phase reactant levels with alterations in weight and serum albumin in patients receiving immunotherapy with recombinant IL‐2 , 1994, Clinical and experimental immunology.

[29]  A. Bernstein,et al.  A method of uniform stratification of risk for evaluating the results of surgery in acquired adult heart disease. , 1989, Circulation.

[30]  F. Grover,et al.  Identification of patients at greatest risk for developing major complications at cardiac surgery. , 1990, Circulation.

[31]  A. Baue.  The role of the gut in the development of multiple organ dysfunction in cardiothoracic patients. , 1993, The Annals of thoracic surgery.

[32]  B. Gersh,et al.  Early and late results after isolated coronary artery bypass surgery in 159 patients aged 80 years and older. , 1990, Circulation.