Acute Hemodilution: Its Effect on Hemodynamics and Oxygen Transport in Anesthetized Man

The effects of acute normovolemic hemodilution on hemodynamics, oxygen transport, tissue perfusion and blood volume were studied. The subjects were four patients undergoing total hip replacement with prebleeding and hemodilution under fluoroxene and nitrous oxide anesthesia. The hematocrit was reduced to 29% and 21% by bleeding in two steps with simultaneous infusion of plasmanate and lactated Ringer's solution. The major compensation was a rise in CO to 123% and 136%. Systemic oxygen transport (COX arterial O(2) content) was only slightly reduced and the arteriovenous oxygen difference decreased. Tissue perfusion remained excellent. Blood volume was slightly expanded. The procedure was well tolerated by this group of selected patients, and homologous blood utilization was markedly reduced.     

Lumbar spine: pretest predictability of CT findings

Demographic and symptomatic data gathered from 460 patients referred for lumbosacral CT examinations were analyzed to determine if the prescan probability of normal or abnormal findings could be predicted accurately. We were unable to predict the presence of herniated disk on the basis of patient-supplied data alone. Age was the single most significant predictor of an abnormality and was sharply related to degenerative disease and spinal stenosis.     

Thoracentesis in the emergency department

Presented is a review of thoracentesis, a procedure with which the emergency physician should be familiar. The pathophysiology of pleural effusions is described and is followed by a review of the clinical presentation and diagnosis. Special attention is given to technique and interpretation of results.     

Estradiol and progesterone influence a serotonin mediated behavioral syndrome (myoclonus) in female guinea pigs: Comparison with steroid effects on reproductive behavior

L-5-hydroxytryptophan (L-5-HTP)-induced myoclonus was used as a behavioral index of central serotonergic activity. Estradiol benzoate (EB) and progesterone (P) influenced the induction of myoclonus by L-5-HTP. When L-5-HTP was injected 46 h after EB, myoclonus was enhanced. P blocked this effect on EB when 100 or 125 mg/kg L-5-HTP (but not 80 mg/kg) was given 6 h after P in EB-primed animals. When L-5-HTP was given 3 or 11-15 h after P in EB-primed animals, there was no inhibitory effect of P on myoclonus. In fact, at the lowest dose (80 mg/kg), L-5-HTP increased myoclonus when given 3 h after P in EB-primed animals. The inhibitory effects of P in EB-primed females on myoclonus were temporally correlated with the display of lordosis, suggesting that the neural progestin receptor mechanisms that have been proposed to mediate P effects on lordosis are also involved in the inhibitory effects of P on myoclonus.     

Fetal gallstones

Routine obstetric ultrasound (US) examinations in a 33-year-old woman revealed a normal fetal gallbladder at 24 menstrual weeks but multiple structures in the gallbladder with findings typical of gallstones at 37 menstrual weeks. No other abnormalities were present. Three days after a term delivery, an abdominal US examination again demonstrated multiple gallstones. When the infant was 6 weeks old, a follow-up abdominal US study showed no evidence of gallstones. This case, as well as one previously reported, demonstrates that findings typical of gallstones may be seen in the fetus, and that these structures may spontaneously resolve.