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D C Cheng

Publications and source records attributed to D C Cheng.

At least 37 records · Page 2Linked to original sources
PubMed1998

Fast-track cardiac surgery: economic implications in postoperative care.

Economics is the main driving force in changing health care delivery in the 90s. The motto is to "do more with less." Cost containment and efficient resource utilization swing the pendulum back to the debate of early tracheal extubation in cardiac surgical patients. Recently, it has been confirmed that fast-track cardiac anesthesia is both safe and cost-effective. This article describes the economic implications in postoperative care of fast-track cardiac surgery. First, the developments of early extubation postcardiac surgery and the factors that influence costs of cardiac surgery are reviewed. Second, the morbidity outcome, utilization, and cost implications of early extubation in cardiac surgery are summarized. The perioperative cost analysis in fast-track cardiac surgery, including the cost of complications and resource utilization, is outlined. Lastly, it is important to realize that early extubation does not necessarily mean earlier intensive care unit or hospital discharge. To achieve a maximum cost benefit from early extubation, team organization of a fast-track cardiac surgery program for the perioperative management of these patients is detailed.

Anesthesia↗
PubMed1998

The effect of three different doses of tranexamic acid on blood loss after cardiac surgery with mild systemic hypothermia (32 degrees C).

OBJECTIVE: Prophylactic administration of tranexamic acid (TA), an antifibrinolytic agent, decreases bleeding after cardiac surgery with systemic hypothermia (25 degrees C to 29 degrees C). Warmer systemic temperatures during cardiopulmonary bypass (CPB) may reduce bleeding and thus alter the requirement for TA. The effect of three different doses of TA on bleeding after cardiac surgery with mild systemic hypothermia (32 degrees C) is evaluated. DESIGN: Double-blind, prospective, randomized study. SETTING: University hospital. PARTICIPANTS: One hundred fifty adult patients undergoing aortocoronary bypass or valvular cardiac surgery. INTERVENTIONS: Patients received TA, 50 (n = 50), 100 (n = 50), or 150 (n = 50) mg/kg intravenously before CPB with mild systemic hypothermia. MEASUREMENTS AND MAIN RESULTS: Blood loss through chest drains over 6, 12, and 24 hours after surgery and total hemoglobin loss were measured. Autotransfused blood, transfused banked blood and blood products, and coagulation profiles were measured. Analysis of variance on log-transformed data for blood loss and confidence intervals (CIs) of 0.95 were calculated and transformed to milliliters of blood. No patient was re-explored for bleeding. Blood loss at 6 hours was statistically greater in the 50-mg/kg group compared with the other two groups (p = 0.03; p = 0.02). Total hemoglobin loss was statistically greater in the 50-mg/kg group compared with the 150-mg/kg group (p = 0.04). There was no statistical difference in blood tranfusion rate or coagulation profiles among the three groups. However, preoperative hemoglobin level was statistically lower in the 150-mg/kg group compared with the other two groups (p = 0.01). CONCLUSION: Of the three doses of TA studied, the most efficacious and cost-effective dose to reduce bleeding after cardiac surgery with mild hypothermic systemic perfusion is 100 mg/kg.

Adult↗
PubMed1998

Epidural bupivacaine-morphine analgesia versus patient-controlled analgesia following abdominal aortic surgery: analgesic, respiratory, and myocardial effects.

BACKGROUND: The efficacy and effects of epidural analgesia compared with patient-controlled analgesia (PCA) have not been reported in patients undergoing major vascular surgery. We compared the effects of epidural bupivacaine-morphine with those of intravenous PCA morphine after elective infrarenal aortic surgery. METHODS: Forty patients classified as American Society of Anesthesiologists physical status 2 or 3 received general anesthesia plus postoperative PCA using morphine sulfate (group PCA; n = 21) or general anesthesia plus perioperative epidural morphine-bupivacaine (group EPI; n = 19) during a period of 48 h. During operation, EPI patients received 0.05 mg/kg epidural morphine and 5 ml 0.25% bupivacaine followed by an infusion of 0.125% bupivacaine with 0.1% morphine (0.1 mg/ ml); group PCA received 0.1 mg/kg intravenous morphine sulfate. Continuous electrocardiographic monitoring (V4 and V5 leads) was performed from the night before surgery until 48 h afterward. Respiratory inductive plethysmographic data were recorded after tracheal extubation. Visual analog pain scores at rest and after movement were performed every 4 h after extubation. RESULTS: Nurse-administered intravenous morphine and time to tracheal extubation were less in group EPI, as were visual analog pain scores at rest and after movement from 20 to 48 h. Complications and the duration of intensive care unit and hospital stay were comparable. There was a similar, low incidence of postoperative apneas, slow respiratory rates, desaturation, and S-T segment depression. CONCLUSIONS: Epidural morphine-bupivacaine is associated with reduced early postoperative intravenous opioid requirements, more rapid tracheal extubation, and superior analgesia after abdominal aortic surgery, with comparable respiratory effects.

Aged↗
PubMed1998

Intraoperative awareness in fast-track cardiac anesthesia.

BACKGROUND: Fast-track cardiac anesthesia, using low-dose narcotics combined with short-acting anesthetic and sedative agents, facilitates early tracheal extubation after cardiac surgery. The incidence of awareness with this anesthetic technique has not been investigated previously. The purpose of this study was to prospectively investigate the incidence of intraoperative awareness with explicit memory of events during fast-track cardiac anesthesia. METHODS: Data were collected prospectively over a 4-month period from 617 consecutive adult patients undergoing cardiac surgery at a university hospital. All patients received a fast-track cardiac anesthetic regimen. Patients underwent a structured interview by a research nurse 18 h after extubation. A standard set of questions was asked during this interview to determine if the patient had explicit memory of any event from induction of anesthesia to recovery of consciousness. RESULTS: Nine patients did not complete a postoperative interview because of death (n = 7) or postoperative confusion (n = 2). The last memory before surgery reported in 420 (69.1%) patients was waiting in the holding area at the operating suite, and in the remaining 188 (30.9%) patients it was lying on the operating table before induction of anesthesia. Two patients (0.3%) had explicit memory of intraoperative events. One of the two patients also had explicit memory of pain. Neither patient reported adverse psychological sequelae. CONCLUSIONS: The authors report an incidence of awareness in fast-track cardiac anesthesia of 0.3%. This is the lowest incidence of awareness currently reported during cardiac surgery. This low incidence of awareness may be related to the use of a balanced anesthetic technique involving the continuous administration of volatile (isoflurane) or intravenous (propofol) anesthetic agents before, during, and after cardiopulmonary bypass.

Anesthesia↗
PubMed1998

Impact of early tracheal extubation on hospital discharge.

Economic realities of the continuing increased utilization of cardiac surgery in the 1990s have led to the practice of early tracheal extubation and shortening of the length of intensive care unit and hospital stays. In this era of cost-containment and physician report cards, we are held accountable for patients' outcome in terms of mortality, morbidity, quality of life, length of stay, and cost of care. This report outlines the factors that influence costs of cardiac surgery. These include patient risk, anesthesia, surgical, intensive care unit, and health care systems or hospital factors. The current literature on outcome, utilization, and cost implications of early tracheal extubation in cardiac surgery is summarized and discussed. It has been demonstrated that early extubation anesthesia is safe and cost-effective and can improve resource utilization in cardiac surgery, but to achieve a maximum cost benefit from fast-track or early extubation anesthesia in cardiac patients, team organization of a fast-track cardiac surgery program must be implemented. A perioperative clinical pathway management in fast-track cardiac surgery is presented.

Anesthesia, General↗
PubMed1997

Comparison of lorazepam alone vs lorazepam, morphine, and perphenazine for cardiac premedication.

PURPOSE: To compare the effects of two premedication regimens on cardiorespiratory variables, sedation, and anxiety in patients scheduled for coronary artery bypass graft (CABG) surgery. METHODS: This was a prospective randomized, double-blind clinical trial. Sixty-eight patients were monitored for 1.5 hr before and 2.0 hr after premedication with lorazepam (0.03 mg.kg-1 sl), morphine (0.15 mg.kg-1 im), and perphenazine (0.05 mg.kg-1 im) [Group 1], or with lorazepam (0.03 mg.kg-1 sl) and saline (1.5 ml im) [Group 2]. All were continuously monitored with a 12-lead ECG ST monitors, respiratory inductive plethysmography (RIP), digital pulse oximetry, intra-arterial blood pressure, and arterial blood gas analysis. Sedation and anxiety scores were also recorded. RESULTS: The incidence and duration of myocardial ischaemia was low and similar in Groups 1 and 2. Patients in Group 1, but not in Group 2, had a greater number of events (P < 0.04) and duration (P < 0.02) of O2 desaturation; higher PaCO2 (P < 0.001), and more haemodynamic events (P < 0.006) after premedication when compared with baseline. There was no difference in RIP or ECG variables between the two groups. Following premedication, both groups reported reduced anxiety scores and elevated sedation scores (P < 0.01), with sedation greater in Group 1 than in Group 2 (P < 0.01). CONCLUSION: In CABG patients, premedication with lorazepam provides adequate anxiolysis and sedation, and the addition of morphine and perphenazine results in elevated PaCO2, arterial haemoglobin desaturation, and potentially adverse haemodynamic changes.

Aged↗
PubMed1996

Comparison of nifedipine and metoprolol on collateral coronary blood flow in a swine model of chronic coronary obstruction and acute ischaemia during isoflurane anaesthesia.

PURPOSE: This study compared the effects of nifedipine and metoprolol on collateral-dependent myocardial blood flow in a swine model of chronic coronary obstruction and acute ischaemia during isoflurane anaesthesia. METHODS: Collateral coronary circulation was induced in 15 three-week-old piglets by banding of the proximal left anterior descending coronary artery (LAD). After 8-10 wk, the distal LAD was ligated and the open-chest pigs were randomized to receive infusions of either saline, nifedipine (5 micrograms.kg-1.min-1) or metoprolol (10 micrograms.kg-1.min-1) for 30 min during isoflurane anaesthesia (2%). Transient ischaemia was induced by 30 sec occlusion of the left circumflex artery. Arterial blood pressures, heart rate and regional myocardial blood flow (radiolabelled microspheres technique) were measured at the end of drug infusion (baseline) and one minute after transient ischaemia. RESULTS: No differences in the blood flow to the collateral-dependent (CD) myocardium or haemodynamic variables were observed at baseline among the three groups. Following transient ischaemia, in the nifedipine but not in the metoprolol group, blood flow to the CD myocardium was reduced by 28 +/- 24% in the epicardium (P < 0.05) and 56 +/- 20% in the endocardium (P < 0.01), resulting from intercoronary and transmural steal. This was associated with a moderate increase (10%, P < 0.05) in the heart rate in the nifedipine group. CONCLUSIONS: In a swine model of chronic coronary obstruction and acute ischaemia during isoflurane anaesthesia, the collateral coronary blood flow was maintained in the presence of metoprolol, but reduced in the presence of nifedipine following transient ischaemia due to intercoronary and transmural steal.

Adrenergic beta-Antagonists↗
PubMed1996

Morbidity outcome in early versus conventional tracheal extubation after coronary artery bypass grafting: a prospective randomized controlled trial.

INTRODUCTION: We undertook a prospective, randomized, controlled clinical trial to evaluate morbidity outcomes and safety of a modified anesthetic technique to provide shorter sedation and early extubation (1 to 6 hours) than those of the conventional anesthetic protocol used for prolonged sedation and extubation (12 to 22 hours) in patients after coronary artery bypass grafting. METHODS: One hundred twenty patients undergoing elective coronary artery bypass grafting were prospectively assigned randomly to either an early extubation group (n = 60; 15 micrograms.kg-1 fentanyl and 2 to 6 mg.kg-1.hour-1 propofol and isoflurane) or to a conventional extubation group (n = 60; 50 micrograms.kg-1 fentanyl and 0.1 mg.kg-1 midazolam and isoflurane). Cardiac morbidity (postoperative myocardial ischemia, postoperative myocardial infarction, and perioperative sympathoadrenal stress response), respiratory morbidity (postextubation apnea, alveolar-arterial oxygen gradient, pulmonary shunting, oxygen consumption, atelectasis, and reintubation), hemodynamic values and vasoactive medication requirements, intraoperative awareness, postoperative cognitive function, 30 day mortality, and intensive care unit and hospital lengths of stay were compared between the two groups. RESULTS: Fifty-one of the 60 patients in each group (85%) were extubated within the defined time period. Postoperative extubation time and intensive care unit and hospital lengths of stay were significantly shorter in the early group. At 48 hours after operation, there were no significant differences between the two groups in myocardial ischemia incidences, ischemia burdens, or creatine kinase isoenzyme MB levels. Four patients in the conventional group, but not in the early group, had postoperative myocardial infaction. The extubation anesthetics used were effective in suppressing the perioperative plasma catecholamine stress response in both groups. Postextubation apnea characteristics were similar between the groups. Intrapulmonary shunt fraction improved significantly in the early group at 4 hours after extubation. The incidences and degree of atelectasis did not differ significantly between the two groups. The incidences of treated postoperative complications were comparable between the two groups, but three patients in the conventional group died as a result of stroke or postoperative myocardial infarction. CONCLUSION: Early extubation after coronary artery bypass grafting is safe and does not increase perioperative morbidity. There is an improvement in postextubation intrapulmonary shunt fraction and a reduction in intensive care unit and hospital lengths of stay.

Aged↗
PubMed1996

Cocaine toxicity and isoflurane anesthesia: hemodynamic, myocardial metabolic, and regional blood flow effects in swine.

OBJECTIVES: Increasing numbers of people use cocaine recreationally and may require anesthesia care, having recently abused the drug. However, no data currently exist concerning potential interactions between toxic levels of cocaine and volatile anesthetic agents. This study investigated the effects of cocaine infusion on systemic hemodynamics, myocardial metabolism, and regional organ blood flow in relation to depth of isoflurane anesthesia. DESIGN: Prospective, randomized, controlled trial. SETTING: A laboratory at a university medical center. PARTICIPANTS: Twelve miniature pigs. INTERVENTIONS: An open-chest swine model was used. Isoflurane (ISO) was the sole anesthetic, administered at 0.75 and 1.5 minimum alveolar concentration (MAC), and cocaine was infused (n = 6) at a rate of 0.5 mg/kg/min. Control animals (n = 6) received an equivalent amount of normal saline. MEASUREMENTS AND MAIN RESULTS: Systemic and pulmonary arterial pressures and thermodilution cardiac output data were collected at 0.75 MAC and 1.5 MAC ISC. Regional myocardial and blood flows to other organs were measured using radiolabeled microspheres. Arrhythmias and altered ventricular conduction were noted only in the cocaine group, along with significant elevations in diastolic arterial pressure, coronary perfusion pressure, and systemic vascular resistance. Increased subendocardial blood flow occurred during cocaine infusion (p = 0.03); subepicardial perfusion was unchanged. Cerebral (p < 0.01) and spinal cord (p < 0.05) blood flows were reduced in animals receiving cocaine. Other organ blood flows were unchanged with depth of anesthesia or cocaine administration, with the exception of splenic blood flow (p < 0.04). CONCLUSIONS: Moderately toxic cocaine levels occurring during isoflurane at 0.75 MAC and 1.5 MAC are associated with hemodynamic abnormalities, a marked increase in systemic vascular resistance, and a tendency to produce cardiac arrhythmias. A reversal of endo/epicardial myocardial perfusion ratio occurs associated with cocaine infusion during ISO anesthesia. This is probably not related to a primary redistribution of subendocardial blood flow and may be related to a combination of increased myocardial oxygen demand and epicardial coronary vasoconstriction. The reductions in cerebral and spinal cord perfusion observed may explain, in part, the neurologic sequelae of cocaine toxicity.

Anesthetics, Inhalation↗
PubMed1996

Early tracheal extubation after coronary artery bypass graft surgery reduces costs and improves resource use. A prospective, randomized, controlled trial.

BACKGROUND: Economics has caused the trend of early tracheal extubation after cardiac surgery, yet no prospective randomized study has directly validated that early tracheal extubation anesthetic management decreases costs when compared with late extubation after cardiac surgery. METHODS: This prospective, randomized, controlled clinical trial was designed to evaluate the cost savings of early (1-6 h) versus late tracheal extubation (12-22 h) in patients after coronary artery bypass graft (CABG) surgery. The total cost for the services provided for each patient was determined for both the early and late groups from hospital admission to discharge home. All costs applicable to each of the services were classified into direct variables, direct fixed costs, and overhead (an indirect cost). Physician fees and heart catheterization costs were included. The total service cost was the sum of unit workload and overhead costs. RESULTS: One hundred patients having elective CABG who were younger than 75 yr were studied. Including all complications, early extubation (n = 50) significantly reduced cardiovascular intensive care unit (CVICU) costs by 53% (P < 0.026) and the total CABG surgery cost by 25% (P < 0.019) when compared with late extubation (n = 50). Forty-one patients (82%) in each group were tracheally extubated within the defined period. In the early extubation group, the actual departmental cost savings in CVICU nursing and supplies was 23% (P < 0.005), in ward nursing and supplies was 11% (P < 0.05), and in respiratory therapy was 12% (P < 0.05). The total cost savings per patient having CABG was 9% (P < 0.001). Further cost savings using discharge criteria were 51% for CVICU nursing and supplies (P < 0.001), 9% for ward nursing and supplies (P < 0.05), and 29% for respiratory therapy (P < 0.001), for a total cost savings per patient of 13% (P < 0.001). Early extubation also reduced elective case cancellations (P < 0.002) without any increase in the number of postoperative complications and readmissions. CONCLUSIONS: Early tracheal extubation anesthetic management reduces total costs per CABG surgery by 25%, predominantly in nursing and in CVICU costs. Early extubation reduces CVICU and hospital length of stay but does not increase the rate or costs of complications when compared with patients in the late extubation group. It shifts the high CVICU costs to the lower ward costs. Early extubation also improves resource use after cardiac surgery when compared with late extubation.

Aged↗
PubMed1995

Pro: early extubation after cardiac surgery decreases intensive care unit stay and cost.

The recurrent or new trends of early extubation after cardiac surgery are here to stay in the 1990s. The preoperative status does not necessarily predict the postoperative course and prolonged mechanical ventilation following cardiac surgery should not be uncritically considered as routine. All patients should be assessed for tracheal extubation at the earliest opportunity when the criteria are met in the ICU. Early extubation post-cardiac surgery does reduce ICU and hospital length of stay and costs. It also allows early ICU discharge and reduces case cancellations without any increase in postoperative complications and readmission. These studies have emphasized that the change in the process of care to early extubation can affect patient outcome as well as costs in cardiac patient care. The substantial difference in cost savings per cardiac case between "criteria discharge" and "actual discharge" points out the importance of the organization of the process of care being delivered. To achieve maximum cost benefit from early extubation in cardiac patients, the organization of the perioperative management of these patients must be optimized. This process of care includes intraoperative anesthetic modification; organization of ICU and staff expertise; postoperative early extubation and management; acute pain service; ICU discharge policy; utilization of step-down unit and surgical ward; and communication among cardiac patient management teams (cardiovascular surgeon, cardiac anesthesiologist, ICU staff, nurses, respiratory therapists, physiotherapists, and social workers), which are all vital to the success of such a program.

Cardiac Surgical Procedures↗
PubMed1995

A prospective randomized double-blinded study of the effect of intravenous fluid therapy on adverse outcomes on outpatient surgery.

This study investigated the impact of perioperative fluid status on adverse clinical outcomes in ambulatory surgery. Two hundred ASA grade I-III ambulatory surgical patients were prospectively randomized into two groups to receive high (20 mL/kg) or low (2 mL/kg) infusions of isotonic electrolyte solution over 30 min preoperatively. A standardized balanced anesthetic was used. A minimal amount of fluid was given during the intraoperative and postoperative periods. Adverse outcomes were assessed by an investigator blinded to the fluid treatment group at 30 and 60 min after surgery, at discharge, and the first postoperative day. The incidence of thirst, drowsiness, and dizziness was significantly lower in the high-infusion group at all intervals. We recommend perioperative hydration of 20 mL/kg for patients undergoing general anesthesia for short ambulatory surgery.

Acetates↗
PubMed1993

Anaesthesia for non-cardiac surgery in heart-transplanted patients.

This review documents the anaesthetic management, haemodynamic function and outcome in 18 of 86 heart-transplanted recipients, who returned for 32 non-cardiac surgical procedures at the Toronto Hospital from 1985 to 1990. General anaesthesia was administered in eight of the 27 elective operations and four of the five emergency operations. Induction medications included thiopentone (2-4 mg.kg-1), fentanyl (1-7 micrograms.kg-1) and succinylcholine (1-1.5 mg.kg-1). Anaesthesia was maintained with a combination of oxygen/nitrous oxide and isoflurane or enflurane. Muscle relaxation was maintained with vecuronium or pancuronium. No delayed awakening or unplanned postoperative ventilation was observed. Neurolept-anaesthesia was administered to 63.0% and 20.0% of the elective and emergency operations, respectively. The anaesthetics included fentanyl (25-100 micrograms) and midazolam (0.5-1.5 mg) or diazemuls (2.5-5.0 mg). Spinal anaesthesia (75 mg lidocaine) was administered to only two of the 27 elective operations. No important haemodynamic changes were observed in any anaesthetic group, but lower systolic BP was found after induction and during maintenance periods in the patients who received general anaesthesia than in those who received neurolept-anaesthesia. However, no anaesthesia-related morbidity or mortality was noted. This suggests that general, neurolept- and spinal anaesthesia do not affect haemodynamic function or postoperative outcome in heart-transplanted recipients undergoing subsequent non-cardiac surgery.

Adult↗
PubMed1993

Supplemental oxygen does not reduce myocardial ischemia in premedicated patients with critical coronary artery disease.

This randomized, prospective clinical study investigated the effects of supplemental inspired oxygen on arterial hemoglobin desaturation and myocardial ischemia in premedicated patients who have critical coronary artery stenosis, identified predictors for these adverse events, and examined the temporal relationship between hemoglobin desaturation and myocardial ischemia. Before elective coronary artery bypass surgery, 104 patients were monitored continuously by using a real-time electrocardiogram (V4 and V5 leads) recorder and a digital pulse oximeter. After a 2-h baseline monitoring period (Interval A), patients were given sublingual lorazepam 0.03 mg/kg, and were randomized to receive continuous supplemental inspired oxygen by nasal catheters [4 L/min (Oxygen Group, n = 52)] or to receive no supplemental inspired oxygen (Control Group, n = 52) (Interval B). One hour later, all patients received intramuscular morphine 0.15 mg/kg with perphenazine 0.05 mg/kg (Interval C). Interval C lasted 1 h, and the study was terminated. In the Oxygen Group, the incidence of desaturation was 25% before premedication and 11.5% after premedication (NS). In the Control Group after premedication, the incidence of desaturation increased from 25% to 56.9% (P < 0.001). There was no significant difference in the incidence of myocardial ischemia before or after premedication within or between the two groups. Arterial hemoglobin desaturation was not associated temporally with myocardial ischemia at any time. Predictors of desaturation after premedication included absence of supplemental O2, increased weight, age, and occurrence of desaturation before premedication. There were no identifiable predictors for myocardial ischemia after premedication. During Intervals A and C, episodes of hemoglobin desaturation were associated with small but statistically significant increases in mean heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Amrinone therapy for severe pulmonary hypertension and biventricular failure after complicated valvular heart surgery.

We report two cases in which amrinone was used effectively, in addition to the conventional sympathomimetic drug, for the emergence from cardiopulmonary bypass following complicated valvular heart surgery in patients who had severe pulmonary hypertension and biventricular failure. Amrinone was used in combination with isoproterenol in one and dopamine in the other case. The clinical changes were brought about by a 21.5 percent and 53.5 percent decrease in pulmonary blood pressure and pulmonary vascular resistance, respectively. Concomitantly, the mean systemic blood pressure was increased by 50 percent, whereas heart rate decreased by 17.5 percent. This report demonstrates that amrinone can be life-saving in patients with biventricular failure and severe pulmonary hypertension not responding to conventional beta-adrenergic and vasodilator drug therapy.

Adult↗
PubMed1992

Postoperative haemodynamic and pharmacological responses in patients with positive technetium pyrophosphate single-photon emission computed tomography following CABG.

The aim of this prospective study was to evaluate the postoperative haemodynamic variables and medication requirements in patients with perioperative myocardial infarction (PMI), following elective coronary artery bypass graft (CABG) surgery, as documented by technetium pyrophosphate scintigraphy using single-photon emission computed tomography (TcPPi-SPECT). A high-dose fentanyl anaesthetic technique was applied. Twelve of 58 patients (21%) developed PMI with an infarcted myocardial mass of 35.7 +/- 3.9 g. Over the 48 hr postoperative period, patients with positive TcPPi-SPECT (n = 12) did not differ from those with negative TcPPi-SPECT (n = 46) in mean heart rate (below 100 bpm), systolic blood pressure (100-120 mmHg) or central venous pressure (8-16 mmHg). However, patients with positive TcPPi-SPECT had higher pulmonary artery diastolic pressures at 5-8 hr after surgery. No differences were found in the incidence and dosage requirements for postoperative sedative or vasoactive drugs (morphine, diazepam, propranolol, lidocaine, nitroglycerin and nitroprusside) between the two groups. There was no difference in the incidence of dopamine requirement between the groups (positive-scan: 16.7%, negative-scan: 13.0%). However, the dopamine dosage for inotropic support was higher in the positive TcPPi-SPECT group over 24 hr (318.5 +/- 125.2 mg vs 71.2 +/- 24.7 mg, P less than 0.05) and 48 hr (869.1 +/- 19.0 mg vs 142.3 +/- 49.4 mg, P less than 0.001) periods after surgery. We postulate that careful control of postoperative haemodynamic variables did not prevent but may limit the extent of PMI in elective CABG patients.

Coronary Artery Bypass↗