No abstract

The case report presents evidence for the spinal origin of the marked hypertensive responses to noxious stimuli that may occur in organ donors who fulfill the commonly accepted criteria of brain death. Cardiovascular spinal reflex activity does not invalidate these criteria. For the first time, the catecholamine plasma concentrations have been determined during spinal pressor reflex activity. Circulating epinephrine increased more markedly than norepinephrine in both cases, rising to 4.7 and 44 times the baseline concentration respectively. The relation between plasma norepinephrine and epinephrine suggests involvement of the adrenal medulla in the reflex arc. The literature on spinal hemodynamic reflexes is reviewed.

In a randomized double-blind study, midazolam 0.1 mg kg-1 i.m. was compared with diazepam 0.2 mg kg-1 and placebo as premedication for patients undergoing urological interventions under spinal anaesthesia. The sedative and anxiolytic effects of midazolam were evident 5-10 min after administration, and were maximum between 30 and 90 min. After this, rapid recovery was observed. More than 90% of the patients receiving midazolam were totally or partially amnesic for the procedures in the induction room and the operation theatre. Amnesia was not seen in the patients receiving diazepam or placebo and, in contrast to midazolam, diazepam had almost no sleep-inducing effect. In a few patients, the depth of sleep achieved with midazolam 0.1 mg kg-1 was such that co-operation was impaired.

1 The incidence of increased drug metabolism activity as a consequence of multiple drug therapy at a surgical intensive care ward has been studied non-invasively by determinations of daily urinary D-glucaric acid (GA) excretion rates. 2 Among 165 randomly selected patients, GA excretion was stimulated in 76 cases (= 46%).3 Exploratory data analysis showed that increases in GA excretion are primarily due to administration of barbiturates (pentobarbitone, Nembutalg), miconazole (Daktarg) and, to a lesser extent, neuroleptics.4 Surprisingly, the large number of simultaneously administered additional drugs failed to increase GA excretion. 8 y-Glutamyltranspeptidase activity in serum showed no correlation with GA excretion (n = 91).

Ether link cleavage (ELC) of T4 yielding diiodotyrosine (DIT) has recently been shown in vitro to be the major pathway of T4 metabolism in phagocytosing leukocytes. To evaluate this pathway in vivo and the possible clinical relevance of DIT measurements in diseases with increased leukocyte activity, radioimmunological studies on serum levels of DIT and other thyroid parameters were performed in 125 critically ill patients classified into 3 groups with bacterial infections according to the severity of infection and 1 group without infections. While the pattern of iodothyronine and TSH levels typical for severe nonthyroidal disorders, i.e. decreased total T3 and elevated rT3, normal or decreased total T4 and TSH, and normal free T4, was found in all four groups of intensive care patients studied, elevated serum DIT was observed only in those patients whose clinical course was complicated by severe bacterial infections. Serial measurements revealed a close temporal connection between the infection phase and increased DIT levels. Median values and 16th to 84th percentile ranges (in parentheses) of serum DIT (normal range, 0.02-0.55 nmol/L) were as follows: sepsis, 1.38 (0.32-5.14); severe nonsystemic infections such as peritonitis and abscesses, 3.84 (0.24-17.2); moderate infections such as pneumonia and tracheobronchitis, 0.44 (0.18-1.16); and critical illness without infections, 0.14 (0.08-0.30) nmol/L. These elevations of circulating DIT could neither be correlated with changes in renal function nor attributed to drug effects. The results of the present study do not allow any definitive conclusions to be made about the mechanisms underlying the phenomenon of increased serum DIT levels in infections. Apart from this open question, DIT appears to be a relatively specific serum parameter for the presence and course of severe bacterial inflammations. Its measurement could provide useful clinical information, particularly for monitoring the time course of deep-seated infections.