Effects of single dose, postinduction dexamethasone on recovery after cardiac surgery.

BACKGROUND: Corticosteroids have been recommended to facilitate rapid recovery after cardiac surgery. We previously reported that dexamethasone given after induction of anesthesia decreases the incidence of postoperative shivering. We performed a post hoc analysis of the data obtained during that study, focusing on secondary outcomes. METHODS: A total of 235 adult patients undergoing elective coronary or valvular heart surgery were randomized to receive dexamethasone 0.6 mg/kg or placebo after induction of anesthesia. Patients who had pharmacologically treated diabetes mellitus, had hypersensitivity to dexamethasone, or were receiving treatment with corticosteroids were excluded. RESULTS: We found that, compared with placebo, patients receiving dexamethasone were more likely to remain tracheally intubated for 6 hours or less (26.4% vs 10.0%, p = 0.020) and had a lower incidence of early postoperative fever (20.2% vs 36.8%, p = 0.009) and new-onset atrial fibrillation during the first 3 days postoperatively (18.9% vs 32.3%, p = 0.027). However, we could not demonstrate a statistical difference in the intensive care unit or hospital length of stay, or in overall morbidity and mortality. The dexamethasone-treated patients were also more likely to have a higher blood glucose on admission to the intensive care unit (186 mg/dL vs 143 mg/dL, p = 0.012). CONCLUSIONS: Dexamethasone facilitates early tracheal extubation and is associated with a lower incidence of early postoperative fever and new-onset atrial fibrillation. Apart from a treatable decreased glucose tolerance, dexamethasone treatment was not shown to affect morbidity or mortality significantly.

Long-term survival and functional capacity in cardiac surgery patients after prolonged intensive care.

OBJECTIVE: To determine whether hospital discharge alone represents a good outcome for patients who had prolonged intensive care after cardiac surgery by studying their postdischarge survival and functional outcome. The secondary objective is to estimate the proportion of intensive care unit (ICU) resources used by the long-stay (> or = 10 initial consecutive ICU days) patients and to identify preoperative patient characteristics that are associated with a prolonged ICU stay and hospital and long-term survival. DESIGN: Inception cohort study. SETTING: The Cleveland Clinic Foundation, a tertiary care, academic teaching institution. PATIENTS: Cardiac surgery patients with an initial ICU stay of 10 or more consecutive days. INTERVENTIONS: Data were collected daily during hospitalization on every adult who underwent coronary artery bypass graft and/or valve surgery at one institution in 1993. Discharged patients who spent >10 initial consecutive days in the ICU after surgery were contacted by telephone to determine vital status and functional capacity using the Duke Activity Status Index. Total ICU and total hospital direct costs were obtained for each patient. MEASUREMENTS AND MAIN RESULTS: The primary outcome measurements were ICU length of stay, hospital mortality, after-surgery and postdischarge mortality and functional capacity, and relative resource utilization. Of the 2,618 cardiac surgery patients who met the inclusion criteria, 142 (5.4%) had an initial ICU length of stay of 10 or more consecutive days. Of these, 47 (33.1%) died in the hospital. Ninety-four of the 95 discharged patients were followed up (median follow-up, 30.6 months), and 44 of the 94 (46.8%) died during the follow-up period. The median Duke Activity Status Index for the 50 survivors was 26 out of a possible 58.2. The 142 long-stay patients used 50% of the total ICU days and 48% of the total ICU direct cost for all 2,618 patients. CONCLUSIONS: Many survivors of prolonged intensive care die soon after hospital discharge and many longer term survivors have a poor functional state. Therefore, hospital discharge is an incomplete measure of outcome for these patients, and longer follow-up is more appropriate. The relatively small number of patients who require prolonged intensive care consumes a disproportionate amount of the total ICU and total hospital direct cost.

A prospective randomized trial of Duraflo II heparin-coated circuits in cardiac reoperations.

BACKGROUND: Heparin-coated circuits in cardiopulmonary bypass have been shown to decrease the systemic inflammatory responses associated with cardiopulmonary bypass. Previous clinical studies on low-risk patients who had coronary artery bypass grafting (CABG) and received full-dose systemic heparin did not have clearly improved clinical outcomes. We hypothesized that the beneficial effects of heparin-coated circuits might be seen in patients who had cardiac reoperations. METHODS: Three hundred fifty patients who had reoperation with CABG only (58%), or with valve operations (42%) were randomly assigned to receive either a heparin-coated (Duraflo II; study group) or uncoated (control group) circuit. Clinical outcomes were compared and the variables were analyzed using the following three groups: entire populations of study group and control group, subgroup of patients who had CABG reoperation only, and a subgroup who had valve reoperation or combined valve and CABG reoperation. RESULTS: Preoperative variables were the same in both groups. No difference in clinical outcomes could be demonstrated except that the percentage of patients with major bleeding episodes was significantly lower in the study group (1.2% versus 5.4%, p = 0.035). In the subgroup analysis of patients who had valve reoperations, lower blood transfusion requirements in the intensive care unit (p = 0.013) were found in the study group. When the subgroup of patients who had CABG reoperations was analyzed separately, there was a trend toward less reoperation for bleeding in the study group (0% versus 4.0%, p = 0.058). CONCLUSIONS: We conclude that the use of heparin-coated circuits was safe and imparted protection from reoperations for bleeding and major bleeding episodes. Material-independent blood activation (eg, blood-air interface and cardiotomy suction) blunted the total effect of the heparin-coated surface.

Dexamethasone decreases the incidence of shivering after cardiac surgery: a randomized, double-blind, placebo-controlled study.

UNLABELLED: Shivering after cardiac surgery is common, and may be a result of intraoperative hypothermia. Another possible etiology is fever and chills secondary to activation of the inflammatory response and release of cytokines by cardiopulmonary bypass. Dexamethasone decreases the gradient between core and skin temperature and modifies the inflammatory response. The goal of this study was to determine whether dexamethasone can reduce the incidence of shivering. Two hundred thirty-six patients scheduled for elective coronary and/or valvular surgery were randomly assigned to receive either dexamethasone 0.6 mg/kg or placebo after the induction of anesthesia. All patients received standard monitoring and anesthetic management. After arrival in the intensive care unit (ICU), nurses unaware of the treatment groups recorded visible shivering, as well as skin and pulmonary artery temperatures. Analysis of shivering rates was performed by using chi2 tests and logistic regression analysis. Compared with placebo, dexamethasone decreased the incidence of shivering (33.0% vs 13.1%; P = 0.001). It was an independent predictor of reduced incidence of shivering and was also associated with a higher skin temperature on ICU admission and a lower central temperature in the early postoperative period. IMPLICATIONS: Dexamethasone is effective in decreasing the incidence of shivering. The effectiveness of dexamethasone is independent of temperature and duration of cardiopulmonary bypass. Shivering after cardiac surgery may be part of the febrile response that occurs after release of cytokines during cardiopulmonary bypass.

Secular trends in nosocomial bloodstream infections in a 55-bed cardiothoracic intensive care unit.

BACKGROUND: Although bloodstream infections (BSIs) occur more frequently in intensive care unit patients than in ward patients, most studies of nosocomial BSIs in critically ill patients have not distinguished between intensive care unit populations beyond surgical, medical, and pediatric patients. METHODS: The primary objective of this study was to characterize the secular trends in rates of nosocomial BSIs for all pathogens among patients admitted to a busy cardiothoracic intensive care unit in a single tertiary care institution between January 1986 and December 1995. Patients with nosocomial BSIs were identified through continual prospective surveillance. RESULTS: A total of 40,207 patients were admitted to the cardiothoracic intensive care unit during the 10-year study period, and 804 episodes of nosocomial BSIs among 681 patients were identified. The mean crude BSI infection rate was 6.0 per 1,000 patient-care days and increased linearly during the study period (range, 4.4 to 8.1 per 1000 patient-care days), and approached statistical significance (p value = 0.07). The most common organisms causing BSIs were Staphylococcus aureus (12%), coagulase-negative staphylococci (11%), Candida albicans (11%), Pseudomonas aeruginosa (10%), and Enterococci (9%). The leading sources of nosocomial BSIs were primary BSIs (33%), intravascular devices (27%), lower respiratory tract infections (17%), and surgical wound infections (12%). The etiologic fraction or the proportion of deaths in cardiothoracic intensive care unit patients with BSIs was 15-fold higher than those patients without BSIs (37% versus 2.5%, p < 0.001). CONCLUSIONS: Rates of nosocomial BSIs among patients in our cardiothoracic intensive care unit have increased linearly during the past decade and patients with nosocomial BSIs have an increased risk of in hospital mortality.

Immediate postoperative care of cardiac surgical patients.

Anesthetic care of the cardiac surgery patient is a continuum, beginning with the preoperative visit and ending when the patient is ambulatory and breathing well on the postoperative floor. Anesthesiologists are well-suited to provide postoperative care because the respiratory and cardiovascular management techniques are an extension of OR management. Attention to details is as important in the ICU as in the OR and offers the opportunity to forestall or reduce morbidity.

Treatment of postoperative hypertension after coronary artery bypass surgery. Double-blind comparison of intravenous isradipine and sodium nitroprusside.

BACKGROUND: Hypertension commonly occurs after cardiac surgery and requires therapy to prevent the potentially deleterious effects. METHODS AND RESULTS: After coronary artery bypass graft surgery (CABG), 177 patients with elevated blood pressure > or = 90 mm Hg during the initial 6-hour postsurgical period were selected for this random blinded, parallel study to receive intravenous infusions of either isradipine (n = 90) or sodium nitroprusside (n = 87). Isradipine produced a statistically significant decrease in mean arterial pressure (MAP, delta-23 mmHg) during a 90-minute treatment period. Target MAP (< or = 85 mmHg or a decrease of 10 mmHg, if baseline MAP was between 90 and 95 mmHg) was achieved in 94% of patients 30 minutes after initiation of isradipine infusion (total mean dose, 411 micrograms); target MAP was achieved in 75% of nitroprusside-treated patients (total mean dose, 1708 micrograms). The mean time to control MAP was 18 minutes for isradipine compared with 24 minutes for nitroprusside. Global smoothness in MAP control was graded on a scale of 0 (not controlled) to 5 (excellent). Approximately 76% of isradipine-treated patients received a rating of > or = 3 (mean score, 3.5); 40% of the sodium nitroprusside-treated patients achieved a score of > or = 3 (mean score, 2.0). Both isradipine and nitroprusside produced statistically significant reductions in systolic and diastolic blood pressures, a decrease in systemic vascular resistance, and increases in heart rate, cardiac index, and stroke volume index. Isradipine produced no significant decreases in pulmonary artery occlusion wedge pressure compared with nitroprusside. CONCLUSIONS: Intravenous isradipine was effective and well tolerated in patients with hypertension after CABG and offers an additional therapeutic option to treat patients after cardiac surgery.

Propofol versus midazolam for intensive care unit sedation after coronary artery bypass grafting.

OBJECTIVE: To compare the safety and effectiveness of propofol (2,6-diisopropylphenol) to midazolam for sedation of mechanically ventilated patients after coronary artery bypass grafting. DESIGN: Open, randomized, prospective trial. SETTING: Cardiothoracic intensive care unit (ICU), Cleveland Clinic Foundation. PATIENTS: Eighty-four patients with normal or moderately impaired left ventricular function who underwent elective coronary artery bypass graft surgery under high-dose opioid anesthesia. INTERVENTIONS: Patients were randomly selected to receive either propofol (mean loading dose 0.24 mg/kg; mean maintenance dose 0.76 mg/kg/hr) or midazolam (mean loading dose 0.012 mg/kg; mean maintenance dose 0.018 mg/kg/hr). Infusion rates were titrated to keep patients comfortable, drowsy, and responsive to verbal stimulation. Study duration, 8 to 12 hrs; infusions were started in the ICU when patients were awake and hemodynamically stable. MEASUREMENTS AND MAIN RESULTS: During therapy, both groups had lower mean arterial pressures and heart rates compared with baseline measurements; however, the propofol group had significantly lower heart rates than the midazolam group during the first 2 hrs of infusion. The propofol group also had significantly lower blood pressure measurements 5 and 10 mins after the initial dose, although there was no difference during infusion. Baseline cardiac output was measured before starting the infusion, and measurements were repeated during continuous infusion at 4, 8, and 12 hrs. Cardiac output values were similar. Propofol maintenance infusions ranged from 3 to 30 micrograms/kg/min and midazolam infusions ranged from 0.1 to 0.7 micrograms/kg/min. At these infusion rates. both groups had adequate sedation, based on nurse and patient evaluations; however, the propofol group used significantly lower total doses of sodium nitroprusside and supplemental opioids. CONCLUSIONS: Both propofol and midazolam provided safe and effective sedation of coronary artery bypass graft patients recovering from high-dose opioid anesthesia. The reduced need for both antihypertensive medication and opioids seen in the propofol group may be advantageous. However, the hypotension seen after the initial bolus dose of propofol may be a concern. No difference between the two drugs could be demonstrated in time to extubation or ICU discharge, although it is probable that time to extubation was governed more by residual operative opioids than the study agents.

Low factor XIIIA levels are associated with increased blood loss after coronary artery bypass grafting.

Current hematologic approaches to minimize postoperative bleeding have focused principally on antifibrinolytic agents. To explore whether a need might exist to promote clot stabilization independent of steps that might be taken to prevent lysis, we followed levels of the functional A-chain of factor XIII (fibrin stabilizing factor) immunologically in 19 patients undergoing coronary artery bypass grafting. The levels of factor XIIIA together with alterations in fibrinogen were followed at five stages of operation: (1) initial catheter placement (control), (2) heparinization, (3) initiation of cardiopulmonary bypass, (4) discontinuation of cardiopulmonary bypass, and (5) heparin neutralization with protamine sulfate. Significant (p < 0.05) inverse correlations were observed between postoperative chest-tube drainage volumes and levels of XIIIA at stages 1 through 3, and borderline associations (p < 0.1) were observed for stages 4 and 5. Pronounced losses of factor XIIIA accompanied initiation of cardiopulmonary bypass, when levels fell to 43% +/- 12% (standard deviation) of the control value, significantly below the 59% +/- 9% of the control value expected from hemodilution. By comparison, fibrinogen concentrations fell only to the extent attributable to hemodilution, unaccompanied by substantial degradation as indicated by electrophoretic, functional, and immunologic assays. There was a reversible heparin-induced precipitation of fibrin complexes and fibrinogen dimers from the blood on initiation of hypothermia, but these components returned to the circulation on restoration of normothermia. This precipitation was unrelated to losses of factor XIIIA. The findings warrant inference that XIIIA supplementation in deficient states should be considered as an adjunct to other therapies for postoperative bleeding.

Enhanced cardiac performance following cardiopulmonary bypass.

Changes in cardiac performance during coronary revascularization surgery were followed in 22 selected patients with normal or mildly impaired left ventricles; vasoactive or inotropic drugs were generally avoided. Arterial pressure, filling pressures, and cardiac output were measured; stroke volume and work were calculated before induction of anesthesia, following sternotomy, soon after discontinuation of extracorporeal circulation, and one hour postoperatively. Induction and sternotomy were associated with a depressant effect on cardiac performance. After extracorporeal circulation, however, cardiac performance recovered, cardiac output increased to 7 +/- 0.5 l/min from a preoperative control of 4.9 +/- 0.3 L/min (p less than 0.002) without an elevation of atrial pressures. This increase in cardiac output after bypass resulted from decreased afterload and increased preload secondary to hemodilution. Cardiac performance approached control values early in the postoperative period.

Hemodynamic effects of diazepam-vecuronium-fentanyl sequence for induction of anesthesia for coronary artery surgery.

The hemodynamic effects of diazepam (0.2 mg/kg)--vecuronium (0.2 mg/kg)--fentanyl (10 micrograms/kg) sequence was investigated when used for induction of anesthesia and tracheal intubation in eleven patients undergoing CABG. The parameters monitored included HR, SBP, PAP and PCWP. Also, EKG was monitored via a modified V5 lead and C.O was measured by thermodilution. SVR, PVR and SV were computed from the measured parameters. Following induction of anesthesia by diazepam-vecuronium-fentanyl sequence, there was a decrease in SBP by 20.0% (P less than 0.05), in HR by 15.7% (P less than 0.001) in C.O by 13.3% (P less than 0.01) and in SVR by 13.6% (P less than 0.05) of control value. There were no changes in PAP, PCWP, PVR and SV. Coronary perfusion pressure and heart rate product were both decreased following this induction sequence. However, the percentage decrease in PR was higher than that of CPP, affecting favorably the myocardial oxygen supply-demand balance. Orotracheal intubation was followed by an increase of HR by 10.7% (P less than 0.05), SVR by 13% (P less than 0.05) and PCWP by 26% (P less than 0.05) of preceding value. However, all these values did not reach the control awake values. It was concluded that diazepam (0.2 mg/kg)--vecuronium (0.2 mg/kg)--fentanyl (10 micrograms/kg) sequence does not produce serious hemodynamic changes when used for induction of anesthesia and tracheal intubation in patients undergoing coronary artery bypass surgery.

Pattern of hemodynamic alterations during coronary artery operations.

Twenty-four patients were studied to determine the relative importance of cardiac and peripheral factors in the hemodynamic changes associated with coronary artery operations. None had preoperative evidence of ventricular impairment. Anesthetic management was standardized for all. Sequential hemodynamic measurements revealed the following: (1) Five minutes following induction of anesthesia, all hemodynamic indices were stable except for an increase in heart rate (p less than 0.001). Sternotomy and pericardiectomy were followed by a drop in cardiac index (p less than 0.01) and systolic blood pressure (p less than 0.01). (2) Late during bypass, there was a significant, parallel reduction in both hematocrit and systemic vascular resistance (SVR) (p less than 0.001 and 0.01, respectively). (3) Five minutes after termination of bypass, cardiac output was markedly elevated (p less than 0.001) in association with a decrease in SVR (p less than 0.001), marked hemodilution (p less than 0.001), and tachycardia (p less than 0.001). (4) Following sternal closure, and despite the fact that the hematocrit was still reduced (p less than 0.001), there developed a trend of increased mean arterial pressure (MAP) and SVR with a reduction in cardiac index. These changes were further accentuated 1 hour postoperatively. The SVR was 33% higher than in the previous stage (p less than 0.01), whereas the high cardiac index recorded with initiation of bypass declined significantly to preoperative values. Throughout the studies, there was a strong correlation between alterations in hematocrit and changes in cardiac index and SVR. Blood pressure variations showed no correlation with changes in cardiac output but were significantly related to alterations of peripheral resistance. Sequential determinations of plasma renin activity and catecholamine levels showed no significant alterations in either. The alterations reported describe not only group averages but also the behavior of every patient investigated. The results suggest that in patients with normal or only mild left ventricular impairment, the major factor influencing arterial pressure variations during coronary artery operations and in the postoperative period was the change in peripheral resistance rather than alterations in cardiac output. In the treatment of hypotension under these conditions, one should take into account variations in peripheral vascular resistance and not depend solely on assumed changes in myocardial performance.

Moderate hypothermia during carotid endarterectomy.

The present investigation reports 6 cases undergoing carotid endarterectomy, who were operated under moderate hypothermia (28.5-31.5 degrees C) without the use of a shunt; no neurological sequelae were observed post operatively. Moderate hypothermia is recommended as one of the techniques for brain protection in patients undergoing carotid endarterectomy.