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Biomedical subjects

M Hiesmayr

Publications and source records attributed to M Hiesmayr.

At least 19 recordsLinked to original sources
PubMed2003

Influence of intravenous vitamin E supplementation in cardiac surgery on oxidative stress: a double-blinded, randomized, controlled study.

BACKGROUND: I.V. infusions of vitamin E emulsion (all-rac-alpha-tocopherol) may reduce ischaemia-reperfusion injury after elective cardiac surgery. METHODS: Forty patients participated in a prospective, double-blind, placebo-controlled, randomized trial, receiving either placebo or four doses (270 mg each) of all-rac-alpha-tocopherol between 16 h before and 48 h after surgery. We determined plasma concentrations of vitamin E, vitamin C, malondialdehyde, creatine kinase, troponin I and interleukin 6 and other measures of clinical outcome. RESULTS: Infusion of vitamin E caused normalization of vitamin E plasma concentrations during and after surgery, but had no effect on the early increase in malondialdehyde concentration or the decreases in antioxidative capacity and the water-soluble antioxidant vitamin C. CONCLUSIONS: Normalization of plasma vitamin E concentrations with parenteral vitamin E emulsion does not affect biochemical markers of myocardial injury and does not affect clinical outcome after cardiac surgery.

Adult↗
PubMed2001

Diltiazem versus nitroglycerin for myocardial protection following coronary artery bypass grafting as assessed by dobutamine stress echocardiography.

BACKGROUND: Perioperative infusion of the calcium channel antagonist diltiazem reduces the occurrence and extent of postoperative myocardial ischemia. However, recent reports also mention nitroglycerin as the drug of choice to prevent conduit spasm after coronary bypass grafting. The diagnosis of myocardial ischemia in the perioperative setting is still problematic. Dobutamine stress echocardiography (DSE) is an established technique that combines inotropic stimulation with real-time myocardial imaging and delineates normal and abnormal regional contraction patterns. We assessed the perioperative anti-ischemic effects of diltiazem and nitroglycerin during hemodynamic stress using DSE. METHODS: 50 adult patients were included in a prospective randomized study. Diltiazem or nitroglycerin was used from the onset of extracorporeal circulation until 24 h postoperatively. Dobutamine stress echocardiography was performed in a stepwise fashion 2 to 3 h after elective coronary artery bypass grafting. RESULTS: In 42 of 49 patients, dobutamine stress echocardiography either reached a level of 40 micrograms/kg/min dobutamine or achieved the target heart rate. One patient improved in terms of segmental wall motion abnormalities and three patients developed new abnormalities without corresponding electrocardiographic changes. Analysis of ischemia-sensitive parameters showed lower creatine kinase MB (p = 0.032) and troponin I levels (p = 0.1) in the diltiazem group 24 h postoperatively. Heart rate was significantly lower in the diltiazem group (p = 0.0003). CONCLUSIONS: Under conditions of hemodynamic stress, DSE revealed no significant difference between diltiazem and nitroglycerin with regard to renewed ischemia.

Adrenergic beta-Agonists↗
PubMed2001

Mechanical trauma as the major cause of troponin T release after transvenous implantation of cardioverter/defibrillators.

To study the cause of myocardial injury after elective transvenous insertion of a cardioverter/defibrillator, we measured troponin T (TnT) release in 27 patients. Five patients needing only replacement of the generator with threshold testing served as controls. Compared to the control group, a significant increase in TnT occurred in the patients undergoing insertion, which was greatest in the group receiving screw-in electrodes. There was no correlation between TnT and the number and energy of the shocks and the time in fibrillation. Duration of surgery and TnT release were positively associated. Cardiac injury therefore mainly results from mechanical trauma during insertion of the electrodes and only to a lesser degree from electrical and ischemic lesions.

Biomarkers↗
PubMed2000

[Glucose-insulin-potassium (GIK) in prevention and therapy of myocardial ischemia].

Recent times are witnessing a resurge of metabolic interventions in order to preserve myocardial tissue and improve cardiac function after hypoxic or ischaemic events. The basic principle of this therapeutic approach which differs completely from surgical and radiological revascularisation techniques as well as from direct pharmacologic stimulation of contractility by catecholamines or phosphodiesterase inhibitors is illustrated by the effect of glucose-insulin-potassium (GIK) infusions. Physiology of myocardial metabolism and its pathophysiology in hypoxia and ischaemia are discussed in their relation to the administration of GIK with its main effect of switching from the preferential fat oxydation under normal conditions to a greater percentage of glucose utilisation. GIK can be used in therapeutic intention after an ischaemic insult (myocardial infarction, preoperatively) or as a preventive measure (pre-ischaemic) e.g. prior to a planned intervention (cardiac surgery). GIK improves myocardial energy supply, economizes oxygen utilisation, stabilizes hypoxic cells, diminishes the area of infarction, and increases myocardial contractility and coronary blood flow. Both in controlled trials and in meta-analyses, GIK administration resulted in reduced mortality from myocardial infarction. In conclusion, metabolic interventions present a promising alternative or adjunctive therapeutic tool for the restitution or maintenance of myocardial integrity and cardiac function impaired or threatened by ischaemic events.

Clinical Trials as Topic↗
PubMed2000

First clinical experience with the DeBakey VAD continuous-axial-flow pump for bridge to transplantation.

BACKGROUND: A shortage of donor organs and increased numbers of deaths of patients on the waiting list for cardiac transplantation make mechanical circulatory support for a bridge to transplantation a standard clinical procedure. Continuous-flow rotary blood pumps offer exciting new perspectives. METHODS AND RESULTS: Two male patients (ages 44 and 65 years) suffering from end-stage left heart failure were implanted with a DeBakey VAD axial-flow pump for use as a bridge to transplant. In the initial postoperative period, the mean pump flow was 3.9+/-0.5 L/min, which equals a mean cardiac index (CI) of 2.3+/-0.2 L. min(-1). m(-2). In both patients, the early postoperative phase was characterized by a completely nonpulsatile flow profile. However, with the recovery of heart function 8 to 12 days after implantation, increasing pulse pressures became evident, and net flow rose to 4.5+/-0.6 L/min, causing an increase of mean CI up to 2.7+/-0.2 L. min(-1). m(-2). Patients were mobilized and put through regular physical training. Hemolysis stayed in the physiological range and increased only slightly from 2. 1+/-0.8 mg/dL before surgery to 3.3+/-1.8 mg/dL 6 weeks after implantation. CONCLUSIONS: The first clinical implants of the DeBakey VAD axial-flow pump have demonstrated the device to be a promising measure of bridge-to-transplant mechanical support.

Adult↗
PubMed2000

Prostaglandin E(1) does not influence plasmatic coagulation, hepatic synthesis, or postoperative blood loss in patients after coronary-artery bypass grafting.

STUDY OBJECTIVE: To assess whether postoperatively administered prostaglandin E1 (PGE1) might prevent bleeding in patients after coronary artery bypass grafting (CABG). DESIGN: Prospective, randomized, placebo-controlled trial. SETTING: University-affiliated hospital. PATIENTS: 49 patients scheduled for elective CABG surgery. INTERVENTIONS: The PGE1 group received intravenous PGE(1) up to 15 ng/kg/min for 72 hours after surgery, whereas the placebo group received isotonic saline for the same time period. MEASUREMENTS AND MAIN RESULTS: Nine patients (4 in the PGE1 group vs. 5 in the placebo group) had to be excluded because of hemodynamic instability, and 1 in the placebo group because of gastric bleeding. In the remaining 39 patients (20 vs. 19), no significant differences with regard to hemoglobin levels or platelet count could be observed. There was no significant difference between the groups concerning the amount of packed red blood cells, platelet concentrates, or fresh frozen plasma transfused. No significant differences could be observed regarding laboratory markers of coagulation activation or hepatic synthesis either. CONCLUSIONS: PGE1 did not prevent coagulation disturbances and blood loss when administered postoperatively in patients undergoing CABG. The absence of these expected effects might be explained by the concomitant administration of acetylsalicylic acid, whose antiaggregatory acivity seems to exceed the effects of PGE1.

Aged↗
PubMed2000

Pulmonary artery thromboendarterectomy: a comparison of two different postoperative treatment strategies.

UNLABELLED: Pulmonary artery thromboendarterectomy (PTE) is a potentially curative surgical procedure for chronic thromboembolic pulmonary hypertension. It is, nevertheless, associated with considerable mortality caused by postoperative complications, such as reperfusion pulmonary edema (RPE) (i.e., pulmonary infiltrates in regions distal to vessels subjected to endarterectomy) and right heart failure (RHF). However, there are no reports about the influence of different postoperative treatment strategies on complications and mortality. Therefore, we compared two different treatment strategies. In Group I (n = 33), positive inotropic catecholamines and vasodilators were avoided during termination of cardiopulmonary bypass (CPB) and thereafter, and mechanical ventilation was performed with low tidal volumes < 8 mL/kg, duration of inspiration:duration of expiration = 3:1, and peak inspiratory pressures < 18 cm H(2)O. In Group II (n = 14), positive inotropic catecholamines and vasodilators were regularly used for termination of CPB and thereafter, and ventilation was performed with high tidal volumes (10-15 mL/kg) and peak inspiratory pressures up to 50 cm H(2)O. Hemodynamics, the incidence of RPE and RHF, duration of ventilation, morbidity, and mortality were recorded. Cardiac index was comparable before surgery (2.11 +/- 0.09 vs 2.08 +/- 0.09 L. min(-1). m(-2)) and 20 min after CPB (2.26 +/- 0.09 vs 2.60 +/- 0.20 L. min(-1). m(-2)). RPE occurred in 6.1% (Group I) versus 14.3% (Group II), and RHF was observed in 9.1% (Group I) versus 21.4% (Group II). Mortality was 9.1% (Group I) versus 21.4% (Group II). Thus, the avoidance of positive inotropic catecholamines and vasodilators in combination with nonaggressive mechanical ventilation after PTE was associated with a low incidence of RPE, RHF, duration of ventilation, and mortality after PTE. IMPLICATIONS: The avoidance of positive inotropic catecholamines and vasodilators in combination with nonaggressive mechanical ventilation was associated with a low incidence of reperfusion pulmonary edema and/or right heart failure after pulmonary artery thromboendarterectomy.

Adult↗
PubMed2000

Inhaled nitric oxide reduces pulmonary vascular resistance more than prostaglandin E(1) during heart transplantation.

UNLABELLED: Heart transplantation in patients with increased pulmonary vascular resistance is often associated with postbypass right heart failure. We therefore compared the abilities of prostaglandin E(1) (PGE(1)) and inhaled nitric oxide to reduce pulmonary vascular resistance during heart transplantation. Patients undergoing orthotopic heart transplantation for congestive heart failure were randomly assigned to either a PGE(1) infusion at a rate of 8 ng. kg. (-1)min(-1) starting 10 min before weaning from cardiopulmonary bypass (CPB) (n = 34) or inhalation of 4 ppm nitric oxide starting just before weaning from CPB (n = 34). Both treatments were increased stepwise, if necessary, and were stopped 6 h postoperatively. Hemodynamic values were recorded after the induction of anesthesia, 10 and 30 min after weaning from CPB, and 1 h and 6 h postoperatively. Immediately after weaning from CPB, pulmonary vascular resistance was nearly halved in the nitric oxide group but reduced by only 10% in the PGE(1) group. Pulmonary artery pressure was decreased approximately 30% during nitric oxide inhalation, but only approximately 16% during the PGE(1) infusion. Six hours after surgery, pulmonary vascular resistance and pulmonary artery pressure were similar in the two groups. The ratio between pulmonary vascular resistance and systemic vascular resistance was significantly less in the nitric oxide patients at all postbypass times. In contrast, the pulmonary-to-systemic vascular resistance ratio increased approximately 30% in the patients given PGE(1). Cardiac output, heart rate, mean arterial pressure, right atrial pressure, and pulmonary wedge pressure did not differ between the groups. Weaning from CPB was successful in all patients assigned to nitric oxide inhalation; in contrast, weaning failed in six patients assigned to PGE(1) (P = 0.03). IMPLICATIONS: Nitric oxide inhalation selectively reduces pulmonary vascular resistance and pulmonary artery pressure immediately after heart transplantation which facilitates weaning from cardiopulmonary bypass.

Administration, Inhalation↗
PubMed1999

Prognostic performance and customization of the SAPS II: results of a multicenter Austrian study. Simplified Acute Physiology Score.

OBJECTIVES: To evaluate the prognostic performance of the original Simplified Acute Physiology Score (SAPS) II in Austrian intensive care patients and to evaluate the impact of customization. DESIGN: Analysis of the database of a multicenter study. SETTING: Nine adult medical, surgical, and mixed intensive care units (ICUs) in Austria. PATIENTS: A total of 1733 patients consecutively admitted to the ICUs. MEASUREMENTS AND RESULTS: The database included admission data, SAPS II, length of stay, and hospital mortality. The Hosmer-Lemeshow goodness-of-fit test for the SAPS II showed a lack of uniformity of fit (H = 89.1, 10 df, p < 0.0001; C = 91.8, 10 df, p < 0.0001). Subgroup analysis showed good performance in patients with cardiovascular (medical and surgical) diseases as the primary reasons for admission. A new predictive equation was derived by means of the logistic regression. Goodness-of-fit was excellent for the customized model (SAPS IIAM) (H = 11.2, 9 df, p = 0.33, C = 11.6, 9 df, p = 0.24). The mean standardized mortality ratio (SMR) changed from 0.81 +/- 0.26 to 0.93 +/- 0.29 with customization. CONCLUSIONS: SAPS II was not well calibrated when applied to all patients. However, it performed well for patients with cardiovascular diseases as the primary reason for admission and may thus be applied to these patients. Standardized mortality ratios that are calculated from scoring systems without known calibration must be viewed with skepticism.

Austria↗
PubMed1999

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Journal Article↗
PubMed1999

Cerebral oxygenation during cardiopulmonary bypass measured by near-infrared spectroscopy: effects of hemodilution, temperature, and flow.

OBJECTIVE: To determine the effects of hemodilution, PaCO2, PaO2, arterial pressure, and temperature on cerebral oxygenation during mild hypothermic cardiopulmonary bypass (CPB). PARTICIPANTS: Fourteen patients electively scheduled for cardiac surgery. INTERVENTIONS: Oxyhemoglobin (HbO2), deoxyhemoglobin (Hb), hemoglobin differential (Hb-diff = HbO2-Hb), and oxidized cytochrome aa3 (CtO2) were measured with near-infrared spectroscopy (NIRS) during CPB. RESULTS: With onset of CPB, a significant decrease in HbO2 (median, -4.55 micromol/L; 25th to 75th percentile, -5.5 to -3.1; p < 0.05), Hb-diff (median, -3.88 micromol/L; 25th to 75th percentile, -4.7 to -1.9; p < 0.05), and CtO2 (median, -0.05 micromol/L; 25th to 75th percentile, -0.15 to 0; p < 0.001) occurred. The simultaneous decrease in arterial hemoglobin concentration (from 11.7 to 8.5 g/100 mL, p < 0.005) correlated significantly with changes in HbO2 (r2 = 0.71; p < 0.001), Hb-diff (r2 = 0.59; p < 0.005), and CtO2 (r2 = 0.57; p < 0.005). After 24 minutes of CPB, the largest decline in HbO2 (-5.03 micromol/L) and Hb-diff (-5.68 micromol/L) was recorded, whereas CtO2 showed no changes during cooling. During CPB, Hb and Hb-diff significantly correlated with the duration of CPB, PaO2 and PaCO2. CONCLUSIONS: In early stages of CPB, a diminished cerebral oxygen supply was found, which may be caused by acute hemodilution. Despite an increased extraction of oxygen as demonstrated by the decrease in Hb-diff, cerebral energy balance reflected by CtO2 was maintained within a safe range during cooling. Because NIRS measures regional cerebral oxygenation, it is useful as an adjunct to global measures in the early noninvasive detection of cerebral hypoxia.

Blood Pressure↗
PubMed1999

A comparison of the monitors INVOS 3100 and NIRO 500 in detecting changes in cerebral oxygenation.

BACKGROUND: Measurements of cerebral haemoglobin oxygenation of 2 near-infrared spectroscopy devices (INVOS 3100 and NIRO 500) were compared during and after hypocapnia. METHODS: Fifteen awake, healthy volunteers, who hyperventilated to obtain end-tidal CO2 (EtCO2) values of approximately 20 mmHg, were studied. During hyperventilation and 8 min thereafter, EtCO2, INVOS 3100 (RSO2 = regional cerebral oxygenation) and NIRO 500 recordings (HbO2 = oxyhaemoglobin, Hb = deoxyhaemoglobin, Hb-diff = HbO2-Hb, CtO2 = oxidised cytochrome oxidase aa3) were analysed. RESULTS: Hyperventilation induced a significant decline in EtCO2 from 30.5 to 14.7 mmHg (P < 0.001) and RSO2 from 67.1% to 62.7% (P = 0.025). At hypocapnia, only Hb (+1.61 +/- 0.48 mumol/L; P < 0.001) and Hb-diff (-3.01 +/- 2.0 mumol/L; P < 0.001) indicated a decline in cerebral haemoglobin oxygenation. Within 8 min after hyperventilation, both EtCO2 and RSO2 normalised to values insignificantly different from baseline. In contrast, Hb and Hb-diff remained significantly different (Hb: +2.52 +/- 1.28 mumol/l; P < 0.001, Hb-diff: -4.31 +/- 4.0 mumol/L; P < 0.001). A correlation with EtCO2 was found for RSO2 (R = 0.35; P < 0.001) and CtO2 (R = 0.42; P < 0.001). All volunteers were continuously awake and none presented clinical symptoms of cerebral hypoxia. CONCLUSION: Changes in cerebral haemoglobin oxygenation state were reflected more accurately by INVOS 3100 than NIRO 500. The cause may be the different technology of the monitors, since INVOS 3100 eliminates the contribution of extracranial oxygenation.

Adult↗
PubMed1999

Systemic blood pressure and cerebral blood flow velocity during carotid surgery.

BACKGROUND: To evaluate the effect of mean arterial blood pressure (MAP) on cerebral perfusion during carotid surgery, we investigated blood flow velocity in the middle cerebral (Vs,mca) using transcranial Doppler ultrasonography (TCD). METHODS: During carotid crossclamping, treatment included either phenylephrine-induced hypertension without shunting (Group XC; n = 11) or insertion of a shunt (Group S; n = 12). RESULTS: Increasing MAP in Group XC before crossclamping (81 + /-13 mmHg to 107 +/- 12 mmHg) caused an increase of Vs,mca (59 +/- 17 cm/s to 75 +/- 20 cm/s; p < 0.001). During crossclamping without a shunt, Vs,mca was not dependent on MAP, and was reduced (mean 47 +/- 24 cm/s) in relation to preclamp values. In Group S, Vs,mca was always dependent on MAP and the preclamp velocity was maintained (before shunt: 75 +/- 26 cm/sec; during shunt: 79 +/- 30 cm/sec). CONCLUSIONS: Although we found an impaired cerebral autoregulation, Vs,mca was independent of MAP during carotid crossclamping. Thus, TCD measurements have to be interpreted with caution during crossclamping, and the effect of induced hypertension has to be confirmed with more invasive measures of cerebral blood flow.

Aged↗
PubMed1999

Evaluation of an interdisciplinary data set for national intensive care unit assessment.

OBJECTIVES: To evaluate the ability of an interdisciplinary data set (recently defined by the Austrian Working Group for the Standardization of a Documentation System for Intensive Care [ASDI]) to assess intensive care units (ICUs) by means of the Simplified Acute Physiology Score II (SAPS II) for the severity of illness and the simplified Therapeutic Intervention Scoring System (TISS-28) for the level of provided care. DESIGN: A prospective, multicentric study. SETTING: Nine adult medical, surgical, and mixed ICUs in Austria. PATIENTS: A total of 1234 patients consecutively admitted to the ICUs. INTERVENTIONS: Collection of data for the ASDI data set. MEASUREMENTS AND MAIN RESULTS: The overall mean SAPS II score was 33.1+/-2.1 points. SAPS II overestimated hospital mortality by predicting mortality of 22.2%+/-2.9%, whereas observed mortality was only 16.8%+/-2.2%. The Hosmer-Lemeshow goodness-of-fit test for SAPS II scores showed lacking uniformity of fit (H = 53.78, 8 degrees of freedom; p < .0001). TISS-28 scores were recorded on 8616 days (30.6+/-1.5 points). TISS-28 scores were higher in nonsurvivors than in survivors (30.4+/-0.9 vs. 25.7+/-0.4, respectively; p < .05). No significant correlation between mean TISS-28 per patient per unit on the day of admission and mean predicted hospital mortality (r2 = .23; p < .54) or standardized mortality ratio per unit (r2 = -.22; p < .56) was found. CONCLUSIONS: Implementation of an interdisciplinary data set for ICUs provided data with which to evaluate performance in terms of severity of illness and provided care. The SAPS II did not accurately predict outcomes in Austrian ICUs and must, therefore, be customized for this population. A combination of indicators for both severity of illness and amount of provided care is necessary to evaluate ICU performance. Further data acquisition is needed to customize the SAPS II and to validate the TISS-28.

APACHE↗
PubMed1998

[Protein catabolism after lung transplantation and heart transplantation].

Any surgical intervention is associated with an activation of protein catabolism, the extent of which is dependent on the severity of surgical trauma. There is a paucity of reports on protein catabolism after transplantation of chest organs (lung transplantation (LTX) and heart transplantation (HTX)). The aim of the present study was to quantify and compare the extent of postoperative protein catabolism and associated metabolic perturbations in patients after LTX and HTX. Eighteen consecutive patients after LTX and 15 consecutive patients after HTX who required postoperative intensive care for more than 4 days, constituted the study population. The nitrogen balance (assessed on the basis of the urea nitrogen production rate and nitrogen intake) was assessed retrospectively and correlated with insulin requirements, immunosuppression and the clinical course. Within the first 5 days the nitrogen balance became progressively negative in both groups, reaching a maximum on the 5th day. Thereafter the nitrogen balance of patients following LTX remained negative, whereas the nitrogen balance of patients following HTX tended to improve. The evolution of nitrogen balance significantly differed between both groups (p < 0.01). The mean nitrogen loss was -0.29 +/- 0.17g/kg BW/day after LTX versus -0.22 +/- 0.12g/kg BW/day after HTX. Smaller amounts of glucocorticoids were used for immunosuppression in patients after HTX than in patients after LTX; nevertheless, heart transplant recipients required higher doses of insulin to maintain normoglycemia. A regression analysis revealed that the duration of stay at the intensive care unit (p < 0.001) and the amount of glucocorticoids (p < 0.01) negatively affected the nitrogen balance, whereas an increased protein intake (p < 0.001) exerted a positive effect. Compared to other major surgical procedures, protein catabolism is excessively elevated in patients after thoracic transplantation. Immunosuppressive therapy with glucocorticoids contributes to protein degradation; the nitrogen balance after LTX is more negative than that after HTX because of higher glucocorticoid requirements following LTX. More aggressive nutritional intervention and especially an increased nitrogen intake might help to reduce protein losses in these patients.

Adult↗
PubMed1998

[Risk and procedure education in anesthesiology. Overview of Austrian and German legal regulations].

Informed consent is currently an ethical, medical and legal requirement. An increase in public discussion of real or supposed malpractice has led to critical attitude in patients and increased demands on informed consent by the courts. Unfortunately, the legal requirements of informed consent have developed from atypical situations involving dissatisfied and injured patients rather than from the more usual occurrences of physicians helping patients with subsequent patient satisfaction. In addition, laws have not set forth clear guidelines for physicians to follow. We review the elements of informed consent based on current Austrian and German jurisdiction in the particular field of anesthesiology and summarize the legal and medical realities in order to point out specific criteria for decision making.

Anesthesiology↗
PubMed1998

Tissue heat content and distribution during and after cardiopulmonary bypass at 31 degrees C and 27 degrees C.

BACKGROUND: Afterdrop following cardiopulmonary bypass results from redistribution of body heat to inadequately warmed peripheral tissues. However, the distribution of heat between the thermal compartments and the extent to which core-to-peripheral redistribution contributes to post-bypass hypothermia remains unknown. METHODS: Patients were cooled during cardiopulmonary bypass to nasopharyngeal temperatures near 31 degrees C (n=8) or 27 degrees C (n=8) and subsequently rewarmed by the bypass heat exchanger to approximately 37.5 degrees C. A nasopharyngeal probe evaluated core (trunk and head) temperature and heat content. Peripheral compartment (arm and leg) temperature and heat content were estimated using fourth-order regressions and integration over volume from 19 intramuscular needle thermocouples, 10 skin temperatures, and "deep" foot temperature. RESULTS: In the 31 degrees C group, the average peripheral tissue temperature decreased to 31.9+/-1.4 degrees C (means+/-SD) and subsequently increased to 34+/-1.4 degrees C at the end of bypass. The core-to-peripheral tissue temperature gradient was 3.5+/-1.8 degrees C at the end of rewarming, and the afterdrop was 1.5+/-0.4 degrees C. Total body heat content decreased 231+/-93 kcal. During pump rewarming, the peripheral heat content increased to 7+/-27 kcal below precooling values, whereas the core heat content increased to 94+/-33 kcal above precooling values. Body heat content at the end of rewarming was thus 87+/-42 kcal more than at the onset of cooling. In the 27 degrees C group, the average peripheral tissue temperature decreased to a minimum of 29.8 +/-1.7 degrees C and subsequently increased to 32.8+/-2.1 degrees C at the end of bypass. The core-to-peripheral tissue temperature gradient was 4.6+/-1.9 degrees C at the end of rewarming, and the afterdrop was 2.3+/-0.9 degrees C. Total body heat content decreased 419+/-49 kcal. During pump rewarming, core heat content increased to 66+/-23 kcal above precooling values, whereas peripheral heat content remained 70+/-42 kcal below precooling values. Body heat content at the end of rewarming was thus 4+/-52 kcal less than at the onset of cooling. CONCLUSIONS: Peripheral tissues failed to fully rewarm by the end of bypass in the patients in the 27 degrees C group, and the afterdrop was 2.3+/-0.9 degrees C. Peripheral tissues rewarmed better in the patients in the 31 degrees C group, and the afterdrop was only 1.5+/-0.4 degrees C.

Adult↗