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Biomedical subjects

R J Palahniuk

Publications and source records attributed to R J Palahniuk.

At least 19 recordsLinked to original sources

The effect of heated wire circuits on humidification of inspired gases.

We performed this study to determine the effect of heated wire circuits on humidity delivered by several humidifiers commonly used during anesthesia. Humidifier bases from three manufacturers with several humidifying chambers for each base were tested using both heated and unheated circuits. Delivered humidity and circuit temperature were measured at the distal end of the circuit. Each chamber was tested under both continuous flow (CF) and intermittent flow (IF) conditions. IF was provided by a Servo 900 B ventilator. Adjustments of flow and volume were made for pediatric chambers. At 90 L/m CF, humidifier performance was unsatisfactory with both heated and unheated circuits. At 15 and 45 L/m CF, both distal circuit temperature (DCT) and humidity were within acceptable limits; unheated circuits delivered more humidity than heated circuits (P < 0.05). Relative humidity was lower at 45 L/m CF than at 15 L/m (P < 0.05). During IF while all chambers provided satisfactory humidity, humidity was greater when unheated circuits were used. We conclude that when heated circuits are used, humidifying systems may fail to deliver 100% humidity to patients.

Adult↗

High levels of carbon monoxide are produced by electro-cautery of tissue during laparoscopic cholecystectomy.

Pyrolysis of tissue in a hypoxic environment can produce carbon monoxide. The atmosphere of the peritoneal cavity is rendered hypoxic during laparoscopic cholecystectomy by insufflation with 100% carbon dioxide. To determine whether carbon monoxide is produced by electrocautery of tissue during laparoscopic cholecystectomy, nine patients undergoing this procedure had the insufflation gas after use of electrocautery analyzed for carbon monoxide. Blood was analyzed for carboxyhemoglobin in these same patients to determine whether carbon monoxide was being absorbed in dangerous amounts. Carbon monoxide was present in the peritoneal cavity 5 min after use of electrocautery was initiated at a median concentration of 345 ppm (range 25-1600 ppm), and at the end of surgery at a concentration of 475 ppm (range 100-1900 ppm). This was well in excess of the 35 ppm upper limit for a 1-h exposure set by the Environmental Protection Agency. The carboxyhemoglobin concentrations (mean +/- SD) were the same at the beginning (1.3% +/- 0.7%), end (1.2% +/- 0.7%), and the day after surgery (1.1% +/- 0.6%). Although there was no evidence of significant absorption of carbon monoxide in these patients, care should be taken to scavenge the gases produced by cautery of tissues to avoid operating room contamination during laparoscopic surgery.

Adolescent↗

Effectiveness of preoperative sedation with rectal midazolam, ketamine, or their combination in young children.

To determine which of three types of rectal sedation was most effective preoperatively in facilitating parental separation and intravenous cannulation in young children, 100 children 3.0 +/- 1.7 (mean +/- SD) yr of age were randomly assigned to four equal groups. One group (M-K-A) received rectal midazolam (0.5 mg/kg), ketamine (3 mg/kg), and atropine (0.02 mg/kg). The other sedation groups received the same doses of midazolam and atropine (M-A) or ketamine and atropine (K-A) alone, and the control group (A) received only rectal atropine. Most children in either the M-K-A (100%) or M-A (92%) groups separated easily from their parents without struggling or crying, significantly more than in the K-A (60%) or A (64%) groups. However, more children in the M-K-A group (44%) were asleep during separation than in the M-A group (8%; P < 0.05). Only 20% of the children in the M-A or M-K-A groups cried during intravenous catheter placement, significantly less than in the K-A (56%) or A (92%) groups. Intravenous catheter placement was also successful significantly more often in the M-A (80%) and M-K-A (84%) groups than in the K-A (48%) or A (40%) groups. Complications were similar among the groups, but there was evidence that midazolam prolonged recovery time in some patients. Rectal midazolam with or without ketamine is a useful technique when intravenous catheter placement before induction of anesthesia is desired.

Administration, Rectal↗

Kidney transplantation.

Kidney transplantation in adults, infants, and children is a safe and effective treatment of ESRD. In 1990, for all patients with irreversible ESRD, transplantation is the preferred treatment over dialysis. With careful perioperative management by the surgeon and anesthesiologist, the morbidity is very low. Thus increased use of grafts from living donors appears warranted. Continued refinements and advances in immunosuppression should result in even better long-term graft and patient survival.

Adult↗

Is dantrolene safe to administer in sepsis? The effect of dantrolene after endotoxin administration in dogs and rats.

Hyperthermia from septic shock may be indistinguishable from malignant hyperthermia. Dantrolene may be given in septicemia if the diagnosis is unclear. To determine if dantrolene is safe to use in sepsis, two studies were performed. In study 1, 18 anesthetized dogs in which profound septic shock was induced with 5 mg/kg of intravenous Escherichia coli endotoxin were randomized to receive (30 min later) intravenous injections of 10 mg/kg of dantrolene solution, the diluent of dantrolene, or maintenance intravenous fluids alone. The use of dantrolene solution and the diluent of dantrolene resulted in similar but transient statistically significant increases in the cardiac filling pressures and cardiac outputs and decreases in the vascular resistances compared with the control dogs. In a second study, 185 rats were randomized into five equal groups. Groups 1, 2, and 3 received 15 mg/kg of intraperitoneal Escherichia coli endotoxin followed 30 min later by 10 mg/kg of dantrolene solution, the diluent of dantrolene, or normal saline. Groups 4 and 5 received normal saline followed by dantrolene or normal saline. The survival of groups 1, 2, and 3 was less at 24 h (P less than 0.0001) than that of either control group, but was not significantly different from one another. The results suggest dantrolene can be administered safely under clinical conditions where the cause of hyperthermia and shock cannot clearly be ascribed to malignant hyperthermia or septicemia.

Analysis of Variance↗

Anesthetic management of infants receiving an adult kidney transplant.

Renal transplantation in infants has been associated with a high incidence of acute tubular necrosis and of renal artery thrombosis. Since 1978, 24 infants who received an adult kidney transplant at the University of Minnesota have had aggressive administration of intravenous colloids to increase the central venous pressure to 16-20 mm Hg before renal reperfusion. Acute tubular necrosis developed in only two infants, and there were no cases of renal artery thrombosis. Chest radiographic evidence of pulmonary edema was present in the recovery room in seven patients (29%) and within the first four postoperative days in five patients (21%). Yet, only two infants (8.3%) required postoperative mechanical ventilation beyond 24 h to manage fluid overload. With aggressive intravenous colloid administration, infants in renal failure can receive an adult kidney transplant with a low incidence of active tubular necrosis or renal artery thrombosis, but pulmonary edema may develop requiring ventilatory support.

Acid-Base Equilibrium↗

Impaired epidural analgesia after dural puncture with and without subsequent blood patch.

We carried out a retrospective assessment of epidural analgesia in 46 parturients who had a previous dural puncture. Of 29 women who had both dural puncture and blood patch previously, only 59% had an uncomplicated successful second epidural anesthetic. Of 17 parturients who had dural puncture but no blood patch previously, only 65% had an uncomplicated successful subsequent epidural anesthetic. In comparable groups of parturients without previous dural puncture, 88%-92% had successful epidural analgesia. The data suggest that dural puncture may lead to impaired epidural analgesia subsequently. Epidural blood patch after dural puncture did not lead to any further decrease in the rate of good analgesia with subsequent epidural anesthetics. Parturients who request epidural analgesia and who have had previous dural puncture with or without blood patch should be informed about the 35%-40% chance of poor epidural analgesia.

Adult↗

Anesthesia for cesarean section--effects on neonates.

The effects of general and regional anesthesia on neonates after cesarean section have been studied mainly on elective cases. In this paper we studied infants delivered by elective and nonelective cesarean section at the Winnipeg Women's Hospital from 1975 to 1983 (n = 3940) to determine the effect of anesthetic technique on neonatal outcomes. A trained anesthesia nurse interviewed all parturients and reviewed their antepartum, labor and delivery, and anesthesia records. Assessments of neonatal outcomes were based on 1- and 5-minute Apgar scores, need for positive pressure oxygen by mask or intubation, and neonatal deaths (within 30 days). These outcomes were determined in three subgroups of neonates delivered by cesarean section: those delivered by elective section, those delivered by urgent cesarean section for dystocia or failure of labor to progress, and those delivered by section because of fetal distress. Overall, 12.5% of the infants had 1-minute Apgar scores of 4 or less, and 1.4% had 5-minute Apgar scores of 4 or less. Neonates born to mothers given general anesthesia had worse outcomes than those born to mothers given regional anesthesia. Among neonates delivered after elective section, general anesthesia was associated with a higher incidence of low Apgar scores at 1 minute. In neonates delivered by nonelective section, general anesthesia was associated with higher rates of low Apgar scores at 1 and 5 minutes as well as greater requirements for intubation and artificial ventilation. There were no differences seen in neonatal death rates with general and regional anesthesia in the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Obstetrical↗

Obstetrical anaesthesia at Winnipeg Women's Hospital 1975-83: anaesthetic techniques and complications.

The obstetrical anaesthesia experience of the Winnipeg Women's Hospital from 1975 to 1983 was reviewed (n = 22,925 infants). Use of narcotics in labour for analgesia decreased from 38.7 to 18.3 per cent of the deliveries. For analgesia during spontaneous vaginal deliveries, epidural anaesthesia increased from 6.0 to 24.0 per cent, inhalational analgesia decreased from 53.7 to 3.2 per cent while "no anaesthetic intervention" rose from 40.3 to 72.8 per cent. Use of epidural anaesthesia for Caesarean section increased from 58.7 to 82.6 per cent. The most common acute complications of anaesthesia were hypotension and inadvertent dural puncture during epidural catheterization. The incidence of hypotension decreased from 28.3 to 17.4 per cent during the nine-year period. Dural puncture decreased from 4.7 to 1.1 per cent of all epidural administrations. Postpartum complaints (that were thought to be related to anaesthesia) were mainly headache, back pain and sore throat. The incidence of these complaints also decreased over the study period.

Analgesics, Opioid↗

Paresthesias and motor dysfunction after labor and delivery.

The incidence of paresthesias and motor dysfunction associated with 23,827 deliveries at Winnipeg Women's Hospital during a 9-yr period (1975-1983) was 18.9/10,000 deliveries. All the symptoms resolved within 72 hr after supportive therapy only. The frequency of paresthesias and motor dysfunction was greater in primiparas, women who had forceps- or vacuum-assisted deliveries, and women who had epidural or general anesthesia. Significant neurologic deficits after labor and delivery with or without epidural anesthesia were rare. Epidural anesthesia is a safe technique in this regard.

Anesthesia, Epidural↗