Hemodynamic consequences of porcine kidney xenograft reperfusion in cynomolgus monkeys.

BACKGROUND: After xenograft reperfusion, complement activation may lead to generation of anaphylatoxins and cardiocirculatory instability of the recipient. METHODS: In 13 cynomolgus recipients of either unmodified or human decay accelerating factor transgenic porcine kidneys cardiocirculatory parameters were measured by single indicator transpulmonary thermodilution. RESULTS: After graft reperfusion, recipient cardiac output decreased by 25.4% (P<0.05), intrathoracic blood volume by 22.8% (P<0.05), extravascular lung water increased slightly (P=n.s.). The impairment in cardiac output was neither influenced by the graft's weight or human decay accelerating factor transgenicity. sC3a and sC5b-9 complement levels in the recipient monkeys showed a sharp peak upon reperfusion. CONCLUSIONS: After reperfusion a marked and significant cardiodepression accompanied by relative volume depletion were observed. Analysis of volume status ruled out a mere volume shift as the underlying reason for the observed drop in cardiac output. These data may be relevant for the perioperative management of human recipients of discordant xenografts in the future.

Human cytokine responses to coronary artery bypass grafting with and without cardiopulmonary bypass.

BACKGROUND: Coronary artery bypass grafting (CABG) is associated with a systemic inflammatory response. This has been attributed to cytokine release caused by extracorporeal circulation and myocardial ischemia. This study compares the inflammatory response after CABG with cardiopulmonary bypass and after minimally invasive direct coronary artery bypass grafting (MIDCABG) without cardiopulmonary bypass. METHODS: Cytokine release and complement activation (interleukin-6 and interleukin-8, soluble tumor necrosis factor receptors 1 and 2, complement factor C3a, and C1 esterase inhibitor) were determined in 24 patients before and after CABG or MIDCABG. The maximum body temperature, chest drainage, and fluid balance were recorded for 24 hours after operation. RESULTS: Release of interleukin-6, interleukin-8, and tumor necrosis factor receptors 1 and 2 was significantly higher (p < or = 0.005) in the CABG group than the MIDCABG group just after operation. After 24 hours, a significant increase in interleukin-6 was also found in the MIDCABG group (p = 0.001) compared with preoperative value. Body temperature and fluid balance were significantly higher after CABG (p < or = 0.001). CONCLUSIONS: Minimally invasive direct coronary artery bypass grafting represents a less traumatizing technique of surgical revascularization. The reduction in the inflammatory response may be advantageous for patients with a high degree of comorbidity.

Standard calculation of ethanol elimination rate is not sufficient to provide ethanol substitution therapy in the postoperative course of alcohol-dependent patients.

OBJECTIVE: Alcohol withdrawal syndrome (AWS) is a severe complication during postoperative treatment of alcohol-dependent patients. Besides the use of clomethiazole, clonidine, and benzodiazepines, there is another possible way to prevent AWS by deliberate administration of ethanol. The appropriate dosage of ethanol has not been known up to now and it could be defined according to the average ethanol elimination rate (EER) which, from forensic analysis, is known to be 15 mg/dl per h in a normal population. However, it is questionable whether these data are suitable for the calculation of the correct dosage in alcohol-dependent patients. DESIGN: Preliminary retrospective descriptive study. SETTING: Intensive care unit of a university teaching hospital. PATIENTS: 11 alcohol-dependent patients (9 males, 2 females, mean age 50.8 years, range 33 to 60 years). INTERVENTIONS: Ethanol substitution (ES) by parenteral application. MEASUREMENTS AND RESULTS: Ethanol kinetics were evaluated by repeated measurement of the blood ethanol concentration (BEC) over a period of at least 6 h parallel to the administration of ethanol. The average EER was found to be 28 mg/dl per h with a standard deviation of 11 mg/ dl per h. The minimum value was 18 mg/dl per h and the maximum 50 mg/dl per h. These EERs were significantly higher than the EERs known from forensic analysis. AWS was prevented in all 11 patients. CONCLUSIONS: Close control of BEC and precise adjustment of ethanol administration are necessary prerequisites for ES. The standard EER is not sufficient to define the appropriate ethanol dosage due to enormous variations in the ethanol metabolism of alcohol-dependent patients.

[Pulse oximetry and capnography in intensive care transportation: combined use reduces transportation risks]. / Pulsoxymetrie und Kapnometrie bei Intensivtransporten: Kombinierter Einsatz verringert das Transportrisiko.

OBJECTIVE: Due to the growing number of diagnostic and therapeutical procedures intensive-care patients must be transported intra- and interhospitally more often. These transports are among the most critical events during intensive-care therapy, with a high incidence of potentially life-threatening mishaps [23]. The aim of this study was to evaluate the possible benefit of the combined application of pulse oximetry and capnometry for patient safety during transport. METHODS: In a prospective clinical study 48 mechanically ventilated patients were allocated at random in 2 main study groups, 24 patients were investigated during interhospital transportation with an ambulance car, the other 24 patients during intrahospital transports. They were classified according to APACHE II and TISS. Blood pressure, heart rate and arterial blood gases were measured at eleven selected times. Twelve randomly chosen patients out of each main study group were monitored additionally with pulse oximetry and capnometry. The results were compared using the Mann-Whitney-U test. P < or = 0.05 was considered significant. RESULTS: Thirty-four patients had a TISS more than 40. The mean APACHE II-Score was 14 +/- 5. The overall incidence of potentially life-threatening mishaps was 9. Six out of these 9 occurred in the 24 patients with additional monitoring and were immediately detected by pulse oximetry or capnometry. CONCLUSIONS: The combination of pulse oximetry and capnometry offers the possibility to detect potentially life-threatening problems in ventilated patients during transport. This allows for early therapeutical consequences and may help to reduce the risk of transports.

[Postoperative therapy of an alcoholic patient with an unusually high ethanol metabolic rate]. / Postoperative Therapie eines alkoholkranken Patienten mit ungewöhnlich gesteigerter Ethanolabbaurate.

To avoid alcohol withdrawal syndrome (AWS) a pre-operative withdrawal, post-operative drug therapy or continued substitution of ethanol may be tried. However, substitution of ethanol needs an exact dosage and has to be controlled very carefully. The dose calculation is based on an assumed breakdown rate of 0.15 g%/1000/h, as evaluated in forensic studies. We report on a patient who throws the basis for these calculations into question. The breakdown rate of this 43-year-old man was extraordinary higher than the average turnover. This high level of the turnover rate occurred with no detectable impairment of the liver or other organs. This case demonstrates the importance of a close control of the blood alcohol level during the post-operative administration of ethanol. The individual doses of ethanol to avoid AWS has to be found individually for each patient.