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After successful centralization of laboratory analyses since more than 30 years, advances in biosensors, microprocessors, measurement of undiluted whole blood and miniaturization of laboratory analyzers are leading nowadays more and more to a re-decentralization in the laboratory medicine. Point-of-care-testing (POCT), which is defined as any laboratory test performed outside central or decentralized laboratories, is becoming more and more popular. The theoretical advantages of POCT are faster turn-around-times (TAT), more rapid medical decisions, avoidance of sample identification and sample transport problems and the need of only small specimen volumes. These advantages are frequently mentioned, but are not associated with a clear clinical benefit. The disadvantages of POCT such as incorrect handling and/or maintenance of the analyzers by nontrained clinical staff, inadequate or even absent calibrations and/or quality controls, lack of cost-effectiveness because of an increased number of analyzers and more expensive reagents, insufficient documentation and difficult comparability of the obtained POCT-results with routine laboratory results, are strongly evident. According to the authors' opinion the decision for the establishing of POCT has only to be made in a close co-operation between physicians and laboratorians in order to vouch for necessity and high quality of the analyses. Taking the local situation into consideration (24-h-central laboratory, etc.) the spectrum of parameters measured by means of POCT should be rigorously restricted to the vital functions. Such analytes should be: hemoglobin or hematocrit, activated whole blood clotting time, blood gases, sodium, potassium, ionized calcium, glucose, creatinine, ammonia and lactate.

The insertion of a Swan-Ganz catheter may cause various complications including intravascular malpositioning due to congenital anomalies of the large veins. A persistent left superior vena cava is the most frequent anomaly of the large vessels. It is usually diagnosed either as an incidental finding at autopsy or during X-ray imaging for confirming proper position of central venous and pulmonary catheters. The incidence of this condition based on autopsy series is approximately 0.3%. CASE REPORT. A 52-year-old patient was admitted to the surgical ICU with the diagnosis of acute pancreatitis. Because of haemodynamic instability, a pulmonary artery flotation catheter was inserted via the left subclavian vein without difficult. The chest radiograph showed the catheter along the left border of the heart going into the right pulmonary artery. An angiographic examination with bolus contrast injection confirmed a persistent left superior vena cava. CONCLUSION. This type of malposition calls for further detailed diagnosis of the vascular status, as the knowledge of accompanying congenital cardiovascular defects is essential for further invasive diagnostic and surgical procedures. The intensivist should be aware of its occurrence in order to not mistake catheters as being present in the arterial circulation or malpositioned outside the venous circulation.

Since ketamine has been incriminated as triggering malignant hyperthermia (MH) [3, 9, 13, 14, 18], but has still been used uneventfully in MH susceptible patients, we performed an in vitro study to examine the safety of ketamine for use in human MH. METHODS. Muscle specimens of 20 patients who had muscle biopsies to diagnose MH were investigated. In every patient diagnostic contracture tests (2 halothane (Hal) and 2 caffeine (Caf) were done according to the protocol established by the European MH group (EMHG). In addition, one test unit for investigating the effect of stepwise increased bath-concentrations of ketamine (5, 10, 20, 60, 120, 240 and 960 mumol/l) and a further one serving as control (no drugs added to the bath) were used. Combined Hal (2 vol%) and Ket (960 mumol/l) tests were performed in 9 patients (4 MHS, 4 MHN, 1 MHEh). Changes in baseline contractures and mechanical twitch tension were evaluated. RESULTS. The diagnostic test showed MHS in 8, MHN in 8 and MHEh in 4 patients. Ketamine did not induce baseline contractures in any of the tests performed. Contractures induced by 2 vol% of halothane in 4 MHS muscles did not change significantly when ketamine was added to the bath (concentration 960 mumol/l). A significant, dose-related decrease in mechanical twitch tension occurred, when ketamine was added to the test. At the highest concentration (960 mumol) twitch tension was reduced by 55%. Twitch tension remained stable in untreated muscles. No significant differences were found between the specimens from MHS, MHN and MHE patients. This reduction in twitch tension was more pronounced in specimens exposed to both halothane (2 vol%) and ketamine (960 mumol/l), resulting in an average decrease of 71%. CONCLUSION. In accordance with Fletcher et al., our results indicate that ketamine - at least in vitro - does not trigger MH. In MHS muscles, ketamine does not augment halothane-induced baseline contractures. The ketamine-induced reduction of mechanical twitch tension in directly stimulated human muscles has not been described before. Analogous findings in frog sartorius muscles can be found in the literature. Whereas the effect of ketamine on indirectly stimulated muscle has been investigated by several authors, the underlying mechanism of ketamine-induced twitch suppression in directly stimulated muscles is not known. Inhibition of calcium release from or accelerated uptake into the sarcoplasmatic reticulum have been reported.

Although the pharmacokinetics of vecuronium are altered by the loss of kidney function, they do not differ significantly between patients with normal renal function and patients with renal failure. Therefore, the drug has become a preferred neuromuscular blocking agent in anuric patients. The author observed complete relaxation--verified by nerve stimulation--for more than 3 h following a single dose of 0.09 mg/kg vecuronium in a patient with chronic renal failure. Liver function was normal, and no drugs known to interact with vecuronium were used. The authors conclude that the altered pharmacokinetics of vecuronium in anuric patients might cause clinically significant effects in some patients.

17 patients undergoing cholecystectomy in non-opiate general anaesthesia received tramadol (n = 7) or fentanyl (n = 10) for immediate postoperative pain relief using the on-demand analgesia computer (ODAC). Heart rate, blood pressure, and respiratory rate were monitored at half-hourly intervals during the 6-h trial period. Arterial blood was withdrawn at hourly intervals for blood gas analyses and beta-endorphin plasma level assays. Fentanyl and tramadol serum levels were determined prior to each on-demand bolus injection during the first 2 h of the study. At the end of the trial period, the quality of analgesia was assessed retrospectively using a visual analog scale. Mean opiate consumption was 0.53 +/- 0.1 mg for fentanyl and 412 +/- 11.6 mg for tramadol, resulting in an equipotency ratio of about 1:980 (relating to body wt., consumption/h, and pain score). No correlation was found between body wt.-based opiate requirements and pain score. Heart rate increased slightly but significantly under both opiates. Fentanyl produced a significant drop in mean arterial pressure by a maximum of 16%, while tramadol left mean arterial pressure unchanged. Respiratory rate, which was elevated initially, dropped significantly in both groups. Arterial pO2 and pCO2 were within the normal range throughout the observation period, reflecting the absence of respiratory side effects. Opiate blood levels showed major inter- and intraindividual variations (minimal and maximal levels for fentanyl ranged from 0.44-3.44 ng/ml, for tramadol from 272-1,900 ng/ml) and were thus poor predictors of the quality of analgesia.(ABSTRACT TRUNCATED AT 250 WORDS)

During the last 4 years different diagnostic procedures for the detection of malignant hyperthermia (MH) susceptibility have been used at the authors' clinical unit; this study was designed to compare the results of these tests. PATIENTS AND METHODS. Since March 1983, 158 patients have been referred for the following reasons: group A: probands (n = 17) who had had symptoms of MH during anesthesia; group B: patients of probands (n = 48) if the latter were not tested because of age (n = 24) or death (n = 2); group C: relatives from MH families (n = 86); group D: patients (n = 5) who developed fever during stress and/or physical activity (n = 3), had myotonia (n = 1), or developed rhabdomyolysis during intensive care (n = 1); group E: controls (n = 2). Two static halothane and two static caffeine tests according to the European protocol were performed in all patients (n = 158). Histological examinations of skeletal muscle (fixed in glutaraldehyde, stained with hematoxylin-eosin, Gieson, and toluidine blue) were done in the first 100 patients; all specimens were scored by the same investigator (E.S.). Score 0: normal; 1: increased number of sarcolemma cores; 2: 1+cores forming groups; 3: 1+2+fiber degeneration; 4: specific changes-myopathies. Plasma levels of creatine kinase (CK) were determined in the first 50 patients. Complete neurological examinations, including electromyography (EMG), were done in ten patients who had increased CK levels as well as histological scores of 3 or 4 (Table 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Patients and Methods: Seventy-two consecutive patients undergoing orthotopic liver transplantation at the Department of Surgery I, University of Vienna Medical School (OLT nos. 1 to 72), were evaluated. Their mean age was 47 years (range: 18-63 years). The indications for liver transplantation are listed in Table 1. All transplant procedures were performed without using a bypass technique. The intraoperative management and surgical procedure have been described elsewhere [7]. Patients were categorized in two groups, each of which was divided in two subgroups. Group I consisted of 18 patients transplanted before the introduction of preoperative plasma exchange. These were retrospectively allocated to two subgroups on basis of their preoperative prothrombin times (PT): A (n = 9): preoperative PT less than 40%; B (n = 9): preoperative PT greater than 40%. The two subgroups of group 2, which contained 54 patients, were compared on a prospective basis: C (n = 32): preoperative PT above 40%; D (n = 22): PT on admission below 40%, preoperative plasma exchange. Comparison of the two subgroups was based on the following parameters: (1) pre-exchange PT (subgroup D); (2) preoperative PT (= PT post-plasma exchange in subgroup D; (3) intraoperative infusion volumes (balanced electrolyte solutions and human albumin to maintain an intravascular colloid osmotic pressure greater than 16 mm Hg); (4) transfusion volumes (whole blood stored for no more than 72 h or packed red cells and fresh plasma, as available; and (5) intraoperative sodium bicarbonate requirements to maintain an arterial pH greater than 7.20., Results: (Table 2) . Prothrombin time (PT): Group 1: Patients in subgroup A had a mean preoperative PT of 34% (range: 15%-40%). This was significantly lower than in subgroup B (74%; 52%-100%; P less than 0.001). Group 2: The pre-exchange mean PT in subgroup D was 27% (12%-39%) vs. 68% in subgroup C (45%-104%), the difference being highly significant (P less than 0.0001). In patients in subgroup D a mean plasma volume of 3638 ml was exchanged by plasmapheresis. This resulted in a significant increase in PT to 55% (Table 3). As a result, the preoperative post-exchange PT in subgroup D was slightly but significantly (P less than 0.005) less than in subgroup C. Transfusion volumes: Group 1: Patients in subgroup A needed significantly more blood units than those in subgroup B (55.3 units [19-110] vs. 18.7 [3-33]).(ABSTRACT TRUNCATED AT 400 WORDS)

Anesthesia in patients susceptible to malignant hyperthermia (MH) is generally considered to be very risky, although - with one notable exception - there are no prospective studies about anesthetic management in a large number of such patients. The prophylactic use of dantrolene has been recommended in MH patients, although there is no strong evidence supporting this - despite the fact that dantrolene may have serious side effects. We therefore decided to report the results of our own anesthetic technique for MH patients, as our technique does not include the prophylactic use of dantrolene. From 1981 to 1988, 19 operations on 16 MH-susceptible patients were performed. Patients 1-4 were pediatric survivors of an MH episode, where MH susceptibility was confirmed by muscle biopsy and in vitro contracture tests in at least one parent; patients 5-7 were survivors of an MH crisis, and they later underwent diagnostic muscle biopsies themselves; all other patients (nos. 8-16) were relatives of MH survivors with positive in vitro contracture tests. Diazepam, pentobarbital, pethidine, and chlorprothixene were used for premedication; no prophylactic dantrolene was given. Anesthesia was induced by thiopentone and was continued by nitrous oxide/oxygen, fentanyl, and droperidol; alcuronium, atracurium, and vecuronium were administered as necessary. Pyridostigmine, atropine, and naloxone were used if appropriate. New or disposable tubings were used for ventilation, and the vaporizers were removed from the anesthesia machines. ECG and body temperature were recorded in all patients; blood pressure was monitored invasively if indicated; end tidal CO2 was monitored whenever possible.(ABSTRACT TRUNCATED AT 250 WORDS)