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Biomedical subjects

G Goldfarb

Publications and source records attributed to G Goldfarb.

At least 19 recordsLinked to original sources
PubMed1992

[Effects of halogenated anesthetics on splanchnic hemodynamic in normo- and hypovolemic cirrhotic rats].

The effects of 1 MAC of either halothane, enflurane or isoflurane on splanchnic haemodynamics were studied in cirrhotic rats that were either normovolaemic or hypovolaemic from haemorrhage. A group of conscious rats acted as the control group. Bile duct ligation had been carried out in all the rats four weeks previously to induce cirrhosis. At the time of the study, all the rats were anaesthetized with ether for catheterization of the left femoral artery and vein, and the left ventricle via the right carotid. The control group was allowed to awake. When the other rats started to recover, they were artificially ventilated with room air and 1 MAC of the halogenated agent. Heart rate and mean arterial blood pressure were monitored continuously. Once the animals had remained steady for one hour, 1.25 ml of blood for 100 g body weight was removed over a 10 min period. PaO2, PaCO2, arterial pH, heart rate, mean arterial blood pressure, cardiac index and regional blood flows (RBF) were measured before, and thirty minutes after the haemorrhage. Cardiac output and RBF were measured using the radioactive-labelled microsphere method. Only 32 animals were finally included, eight in each group. Splanchnic, portal and hepatic arterial blood flows were similar in conscious rats and in those receiving isoflurane or halothane, and were higher than in those receiving enflurane. The lowest splanchnic and portal venous blood flows were found in those rats receiving enflurane. After haemorrhage, these RBF decreased significantly in all groups except in the enflurane group.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Inhalation↗
PubMed1992

White phosphorus poisoning of waterfowl in an Alaskan salt marsh.

The cause of the yearly death of an estimated 1,000 to 2,000 migrating dabbling ducks (Anas spp.) and 10 to 50 swans (Cygnus buccinator and C. columbianus) has remained a mystery for the last ten years in Eagle River Flats (ERF), a 1,000 ha estuarine salt marsh near Anchorage, Alaska, used for artillery training by the U.S. Army. We have gathered evidence that the cause of this mortality is the highly toxic, incendiary munition white phosphorus (P4). The symptoms of poisoning we observed in wild ducks included lethargy, repeated drinking, and head shaking and rolling. Death was preceded by convulsions. Farm-reared mallards dosed with white phosphorus showed nearly identical behavioral symptoms to those of wild ducks that became sick in ERF. White phosphorus does not occur in nature but was found in both the sediments where dabbling ducks and swans feed and in the gizzards of all carcasses collected in ERF. We hypothesize that feeding waterfowl are ingesting small particles of the highly toxic, incendiary munition P4 stored in the bottom anoxic sediments of shallow salt marsh ponds.

Adipose Tissue↗
PubMed1990

Effects of ketamine, halothane, enflurane, and isoflurane on systemic and splanchnic hemodynamics in normovolemic and hypovolemic cirrhotic rats.

The effects of ketamine, halothane, enflurane, and isoflurane on systemic and splanchnic hemodynamics in cirrhotic rats that were either normovolemic or hypovolemic following hemorrhage were characterized. Rats received at random either ketamine (30 mg/kg iv, 1.5 mg.kg-1.min-1 iv), halothane, enflurane, or isoflurane (1 MAC). Conscious rats were considered the control group. Four weeks before hemodynamic studies bile duct ligation was performed in all rats to induce cirrhosis. Hemodynamic measurements were performed using the radioactive microsphere method 1 h after the onset of anesthesia and 30 min after hemorrhage. Anesthetized rat lungs were mechanically ventilated with room air. Before hemorrhage cardiac index was higher in conscious rats and in rats receiving isoflurane than in the other groups (P less than 0.001). Hepatic arterial blood flow was similar in conscious rats and in those receiving isoflurane or halothane and was higher than in those receiving ketamine or enflurane. The lowest splanchnic and portal venous tributary blood flows were observed in rats receiving enflurane. After hemorrhage cardiac index was significantly less than before hemorrhage in all groups, except in rats receiving enflurane. After hemorrhage portal venous tributary blood flow decreased significantly in all groups except in enflurane group. During halothane and enflurane anesthesia hepatic arterial blood flow and hepatic arterial fraction of cardiac output decreased (P less than 0.01) and they were maintained in the other groups. After hemorrhage hepatic arterial fraction of cardiac output in conscious rats was higher than in those receiving ketamine, halothane, or enflurane (P less than 0.05) and was similar to those receiving isoflurane.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Hepatic blood flow in humans during isoflurane-N2O and halothane-N2O anesthesia.

Hepatic blood flow (HBF) (assessed by plasma clearance and hepatic extraction of indocyanine green), cardiac index, and hepatic venous oxygen saturation were measured in patients before and after induction of anesthesia with thiopental, fentanyl, and N2O, and again during halothane (1 MAC)-N2O (n = 5) or isoflurane (1 MAC)-N2O (n = 6) anesthesia before the start of surgery. Induction of anesthesia decreased HBF and cardiac index. Before administration of volatile anesthetics, both groups had similar values of HBF, cardiac index, and hepatic venous oxygen saturation. During anesthesia cardiac index remained stable in both groups, whereas HBF increased significantly with isoflurane but did not change significantly with halothane. Hepatic venous oxygen saturation was also significantly greater during isoflurane than during halothane anesthesia. We conclude that isoflurane increases HBF in anesthetized patients and is associated with a higher hepatic venous oxygen saturation than is halothane.

Adult↗
PubMed1989

Comparative effects of halothane and isoflurane anesthesia on the ultrastructure of human hepatic cells.

The effects of halothane and isoflurane on the ultrastructure of the liver cells in adult patients with normal liver-function tests were compared. After induction of anesthesia with thiopental, fentanyl, and pancuronium, 18 patients were randomly divided into three groups of six each. Anesthesia was maintained with droperidol (droperidol group), with halothane (1.7 MAC, halothane group), or with isoflurane (1.7 MAC, isoflurane group). During the surgical procedure, 1 hr after the induction, a liver biopsy was performed in each patient and processed for light and electron microscopy. All biopsies were normal on light microscopy. On electron microscopy, no mitochondrial abnormalities were found. In all three groups, irregular nuclear membranes, dilation of the rough endoplasmic reticulum, and vesiculation of the smooth endoplasmic reticulum were seen, without any significant differences between the groups. There were significantly more lysosomes in the hepatocytes of patients receiving halothane than in the hepatocytes of patients receiving isoflurane or droperidol. This study shows that halothane can induce ultrastructure abnormalities very early after the beginning of its administration while, under the same conditions, isoflurane does not.

Adult↗
PubMed1988

[Postoperative analgesia: epidural injection of dexamethasone sodium phosphate].

Epidural administration of steroids has been suggested for the prevention of postoperative epidural fibrosis after lumbar lamino-arthrectomy. In order to assess the efficacy of this technique on pain occurring after such surgery, the demand of pentazocine during the first 24 postoperative hours was studied in 39 patients randomly assigned to two groups. Pain intensity was assessed by a five-point verbal scale (0: none; 1: poor; 2: moderate; 3: severe; 4: very severe) at five intervals (0-4, 5-8, 9-12, 13-16 and 17-24 h). The patients in group T (n = 20) did not receive any steroid, whereas those in group C (n = 19) were given, just after the end of surgery, a single dose of dexamethasone (4 mg) via an epidural lumbar catheter previously inserted by the surgeon. In group T, 18 patients required one or several intramuscular injections of pentazocine, whereas only three patients of group C (p less than 0.001) did so. Patients in group T expressed more severe pain (4 moderate, 12 severe, 3 unbearable) than those patients who had received steroids (1 moderate, 1 severe, 1 unbearable). As a consequence, they requested more pain killer (30 injections vs 8 injections, respectively; p less than 0.001) and sooner than patients of the steroid group (8 h vs 12 h; p less than 0.05). It was concluded that epidural administration of dexamethasone was helpful in preventing postoperative pain after lumbar lamino-arthrectomy.

Adult↗