Prevention of postoperative hypotension following spinal anesthesia for TURP: a double-blind randomized controlled trial comparing ephedrine with placebo.

Spinal hypotension (SH) is a common side effect of spinal anesthesia and may also occur after the surgical procedure. In this double-blinded, placebo-controlled, randomised clinical trial fifty patients undergoing transurethral prostatectomy under spinal anesthesia received 10 mg of ephedrine IV before being transferred from the operating table into their bed after the procedure, whereas fifty controls received saline IV. The number of per- and postoperative hypotensive episodes and vasopressor use, time delay between the administration of the study medication and the first hypotensive episode, level of spinal blockade at the start of surgery, pre- and postoperative hemoglobine and sodium concentration, cardiovascular co-morbidity and chronic medication were registered. There was no statistically significant difference in the incidence of postoperative hypotension between the two groups, but Poisson regression of the expected number of postoperative hypotensive episodes per patient showed a protective effect of ephedrine (p < 0.05). The occurence of peroperative hypotension was a risk factor for developing postoperative hypotension (p < 0.05). There was no statistically significant relation between age, level of spinal blockade, cardiovascular co-morbidity or biochemical parameters and the risk of developing per- or postoperative hypotension, except for a correlation between preoperative alpha-receptor blocking drugs and peroperative hypotension (p < 0.05). Postoperative hypotension (recorded incidence 31%) was almost as common as peroperative hypotension (recorded incidence 37%) and occurred as late as 190 minutes after the end of surgery. Ephedrine IV at the end of surgery reduced the number of postoperative hypotensive episodes per patient but did not reduce the overall incidence of postoperative SH.

Is there an evolution in the epidemiology and follow-up of carbon monoxide poisoning victims?

A retrospective study was conducted to investigate for potential changes in the epidemiology of acute carbon monoxide (CO) poisoning and to evaluate the recommendations within the emergency department (ED) on therapy and neurological and social follow-up of these patients. One hundred and sixty-seven patients with a non-intentional CO poisoning in the time period from 1995 to 1997 were reviewed and compared with data of a similar patient population between 1988 and 1990. Both patient groups were matched for age, sex and comorbidity. Comparing the epidemiological data of the two groups, three main evolutions were observed: (1) there is a global reduction in ED admissions for CO poisoning; (2) the number of young victims has a tendency to decrease; (3) the most common CO source has become an insufficiently functioning stove instead of a defective gas water heater. Regarding treatment and follow-up strategies three conclusions could be drawn: (1) the recommendations for hyperbaric-oxygen therapy were strictly followed; (2) the neurological follow-up was poor and has to be ameliorated and revisited; (3) the systematic follow-up by the social worker on the other hand resulted in immediate actions to prevent a second CO poisoning. This recently elaborated protocol for social evaluation emphasizes the important function of the social worker in the ED and the importance of transmural follow-up organized by the ED.

Blood transfusion practice in Belgium. As assessed by a national survey.

In April 1995 the Ministry of Public Health invited all Belgian hospitals to participate to a survey on the use of blood transfusion. The questionnaire presented two parts, the first one devoted to products transfused and the second one to the transfusion organisation in the hospital. 71 hospitals answered: 7 university and 64 general hospitals. All hospitals reported the use of red cells, 31 of them still used whole blood. Surgical departments transfused the greatest absolute amount of units, but the highest intensity (units/bed/year) was observed in intensive care units. 52 hospitals mentioned the use of autologous predeposit. The highest consumption of platelets occurred in medicine but intensive care showed the highest intensity of platelet transfusion. In 41 hospitals platelets were obtained by cytapheresis. The number of plasma units transfused was highly correlated with the quantities of packed red cells and whole blood transfused. Ten hospitals didn't report the use of any blood conservation technique. Returning unused units to the blood bank was allowed in 80% of the hospitals, their return to the transfusion center was permitted in 65% of the hospitals. A transfusion committee existed in only 11 hospitals. Transfusion should be improved by a better education of all physicians and nurses involved with transfusion and by improving standardisation, by better documentation, better reporting and information of all health care workers involved.

Comparative hemodynamic effects of three different parenterally administered lipid emulsions in conscious dogs.

OBJECTIVE: To compare the hemodynamic side effects of three structurally different lipid emulsions. DESIGN: Randomized, controlled, prospective animal study. SETTING: University research laboratory. SUBJECTS: Six chronically instrumented mongrel dogs. INTERVENTIONS: On separate days, all animals were submitted to three different treatments, in a randomized order. After baseline measurements, either a long-chain triglyceride emulsion (treatment 1), a mixed medium-chain triglyceride/long-chain triglyceride emulsion (treatment 2), or an omega3 polyunsaturated fatty acid long-chain triglyceride (PUFA) emulsion (treatment 3) was administered intravenously over 30 mins. MEASUREMENTS AND MAIN RESULTS: Global and regional hemodynamics (sonomicrometry) were recorded for 2 hrs after baseline measurements. Arterial blood gases and plasma concentrations of hemoglobin, triglycerides, total protein, and glucose were recorded for 2 hrs. Long-chain triglycerides did not affect the cardiovascular performance in awake animals. However, medium-chain triglycerides/long-chain triglycerides and omega3 PUFA caused marked increases in systemic vascular resistance (from 1833 +/- 154 to 3277 +/- 163 mm Hg/dynexsec5, p < .05), heart rate (from 89 +/- 6 to 158 +/- 10 beats/min, p < .05), and depressed ventricular performance (wall-thickening fraction [as percentage from baseline] decreased to 53 +/- 9%, p < .05). CONCLUSIONS: Commercially available lipid emulsions can cause profound cardiovascular side effects at high doses, depending on their composition. Whereas long-chain triglyceride emulsions have virtually no effects on hemodynamics in normal dogs, medium-chain triglyceride/long-chain triglyceride, and omega3 PUFA emulsions should be used with caution in critically ill patients with compromised cardiovascular function.

Long-chain triglycerides improve recovery from myocardial stunning in conscious dogs.

OBJECTIVES: Free fatty acid (FFA) oxidation is depressed in the postischaemic stunned myocardium and recovers in parallel with the normalization of contractile performance. Assuming a causal role for this metabolic disturbance in the pathogenesis of stunning, we questioned whether exogenous administration of high dose triglycerides during reperfusion of postischaemic myocardium, could improve its functional recovery. METHODS: Thirteen dogs were chronically instrumented to measure global and regional haemodynamics and to produce a 10 min episode of regional myocardial ischaemia. In 7 dogs, Intralipid 20% was administered i.v. during the reperfusion phase. Contractile recovery of stunned myocardium was compared with control saline treatments. The series were repeated in another 6 animals, but oxfenicine (CPT I inhibitor) preceeded Intralipid during reperfusion. RESULTS: Contractile recovery of stunned myocardium was faster and more extensive when Intralipid was administered during reperfusion than with saline treatment (wall thickening fraction 86 +/- 6% of preischaemic controls versus 52 +/- 11% at 90 min post-reperfusion; P < 0.05). Oxfenicine pretreatment completely abolished this beneficial effect. CONCLUSIONS: Exogenous administration of triglycerides during reperfusion of postischaemic myocardium improves functional recovery from stunning. This beneficial effect most likely operates through enhanced FFA availability and/or oxidation since it could be abolished by selective inhibition of the carnitine palmitoyl I enzyme.

No decisive break-through yet for general anesthesia combined with locoregional anesthesia!

Although on theoretical grounds locoregional anesthesia, because of the claimed suppression of stress response and the ease with which prolonged analgesia can be achieved, seems preferable to general anesthesia, the shortcomings and drawbacks are such that its use is restricted to well chosen indications. The hope that combination anesthesia can overcome the limitations of both techniques remain to be proven whereas the problems that can arise during the combined technique could pose a major threat to the patient.