PubMed Health⌕ Search

Biomedical subjects

J Lerman

Publications and source records attributed to J Lerman.

At least 127 records · Page 7Linked to original sources
PubMed1987

Effects of anaesthesia and surgery on the solubility of volatile anaesthetics in blood.

To determine the effects of anaesthesia and surgery on the solubility of volatile anaesthetics in blood, we measured the blood/gas partition coefficients of enflurane, halothane, isoflurane, and methoxyflurane in vitro in blood obtained from six healthy unpremedicated adults at three different times during isoflurane anaesthesia: awake; 20 minutes after induction of anaesthesia, but before surgical incision; and, 90 minutes after surgical incision. The blood/gas partition coefficients of the four volatile anaesthetics decreased significantly after induction of anaesthesia and after surgical incision (p less than 0.05). Values for haematocrit and the serum concentrations of albumin, globulin, and cholesterol decreased parallel to the decrease in blood/gas partition coefficients.

Adult↗
PubMed1987

The effect of pancuronium on the solubility of aqueous thiopentone.

In this study we identified the precipitate formed when pancuronium bromide (pH 3.9) and sodium thiopentone (pH 10.6) are combined in vitro. A precipitate formed when sufficient pancuronium was added to thiopentone to decrease the pH below 9.25. The precipitate was isolated, redissolved in alkaline solution and identified as thiopentone using ultraviolet spectrophotometry. Pancuronium was soluble in water in the pH range of 2.0 to 12.0, whereas thiopentone was soluble in water only at a pH greater than 9.90. We conclude that thiopentone precipitates when combined with pancuronium because of a pH-dependent decrease in the solubility of thiopentone, rather than a chemical interaction.

Anesthesia↗
PubMed1987

The minimum alveolar concentration (MAC) of isoflurane in preterm neonates.

Studies in fetal lambs suggested that the minimum alveolar concentration (MAC) in preterm neonates may be less than that in full-term neonates and older infants. To determine the MAC of isoflurane in preterm neonates, 20 patients less than 32 weeks gestation at birth and 16 patients 32-37 weeks gestation at birth, all less than 1 month post-natal age, were studied. Following tracheal intubation, the neonates were anesthetized with a predetermined end-tidal concentration of isoflurane in oxygen and air. The move-no move responses to skin incision were recorded, and MAC was determined using the "up-and-down" technique. Heart rate and systolic arterial pressure were recorded awake, before skin incision, and after skin incision. MAC (mean +/- SD) of isoflurane in preterm neonates less than 32 weeks gestation was 1.28 +/- 0.17%, and MAC in neonates 32-37 weeks gestation was 1.41 +/- 0.18% (P less than 0.05). Although heart rate did not decrease significantly in either group during the study, systolic arterial pressure decreased between 20 and 30% below awake values both before and after skin incision in both age groups (P less than 0.01). We conclude that the MAC of isoflurane in preterm neonates less than 32 weeks gestation is significantly less than that in preterm neonates 32-37 weeks gestation, and that systolic arterial pressure decreases to a similar extent at approximately 1 MAC isoflurane in both age groups.

Anesthesia, Endotracheal↗
PubMed1987

End-tidal PCO2 measurements sampled at the distal and proximal ends of the endotracheal tube in infants and children.

To determine whether the site of gas sampling affects end-tidal gas measurements in pediatric patients, end-tidal PCO2 was measured continuously from the distal and proximal ends of the endotracheal tube in 60 infants and children ventilated with an Air-Shields Ventimeter and a partial rebreathing circuit. These data were compared with simultaneous arterial PCO2 measurements. In infants and children weighing greater than or equal to 12 kg, both distal and proximal end-tidal PCO2 values approximated arterial PCO2 measurements. In infants and children weighing less than 12 kg, however, only distal end-tidal PCO2 measurements approximated arterial PCO2 measurements. It is concluded that in infants and children weighing less than 12 kg, accurate end-tidal measurements can be obtained only from the distal end of the endotracheal tube.

Body Weight↗
PubMed1986

Effects of dose and concentration of rectal methohexitone for induction of anaesthesia in children.

To investigate the effect of dose and concentration of rectal methohexitone for induction of anaesthesia, 60 children (ASA physical status 1 or 2) undergoing outpatient surgery were studied. Each child was randomly assigned to receive one of three rectal solutions (each containing atropine 0.02 mg X kg-1): Group A - ten per cent methohexitone, 25 mg X kg-1 (n = 20); Group B - ten per cent methohexitone, 15 mg X kg-1 (n = 20); or Group C - one per cent methohexitone, 15 mg X kg-1 (n = 20). After induction of anaesthesia, or a maximum period of 20 minutes following rectal administration of methohexitone, halothane, nitrous oxide, and oxygen were administered by mask. The time to induction of anaesthesia, complications, postanaesthetic recovery scores, and recovery time did not differ significantly among the three groups. The incidence of failed inductions did not differ significantly between Group A (zero per cent) and Group C (ten per cent) but both were significantly less than Group B (45 per cent) (p less than 0.05). Heart rate increased significantly between 10 and 30 minutes after rectal administration of methohexitone and atropine. The authors conclude that ten per cent rectal methohexitone 25 mg X kg-1 and one per cent rectal methohexitone 15 mg X kg-1 are equally effective for induction of anaesthesia in children and both are significantly more effective than ten per cent methohexitone 15 mg X kg-1.

Anesthesia, Rectal↗
PubMed1986

Neuromuscular blockade for rapid tracheal intubation in children: comparison of succinylcholine and pancuronium.

To compare the effectiveness of succinylcholine and pancuronium for rapid intubation in children, 49 healthy children ages two to eight years were studied. After induction of anaesthesia with thiopentone and atropine, and administration of droperidol, fentanyl, nitrous oxide, and oxygen, each child received one of the following muscle relaxants: succinylcholine 1.5 mg X kg-1 (n = 12), succinylcholine 1.0 mg X kg-1 (n = 13), pancuronium 0.15 mg X kg-1 (n = 11), or pancuronium 0.10 mg X kg-1 (n = 13). The force of thumb adduction was measured by stimulating the ulnar nerve with repetitive supramaximal single twitches (0.15 Hz). The time to 95 per cent twitch depression (mean +/- S.D.) was most rapid with succinylcholine 1.5 mg X kg-1 (40.8 +/- 3.0 seconds) and succinylcholine 1.0 mg X kg-1 (51.8 +/- 14.0 seconds), slowest with pancuronium 0.10 mg X kg-1 (150.9 +/- 38.0 seconds), and intermediate with pancuronium 0.15 mg X kg-1 (80.3 +/- 21.8 seconds) (p less than 0.005). The intubating conditions were excellent in 100% of the children who received succinylcholine 1.5 and 1.0 mg X kg-1, and pancuronium 0.15 mg X kg-1, but were excellent in only 69 per cent of those who received pancuronium 0.10 mg X kg-1. We conclude that succinylcholine 1.5 mg X kg-1 produces the most rapid onset of excellent intubating conditions in children. In children in whom succinylcholine is contra-indicated, pancuronium 0.15 mg X kg-1 provides excellent intubating conditions within 80 seconds.

Child↗
PubMed1986

Exercise testing and thallium-201 myocardial perfusion scintigraphy in the clinical evaluation of patients with Wolff Parkinson White syndrome.

In 58 patients with Wolff Parkinson White syndrome (WPW), we performed exercise stress testing in order to investigate the incidence of normalization of the auriculo-ventricular conduction and the ST-segment changes. For a more accurate evaluation of the latter, exercise and redistribution radionuclide images with Thallium-201 were obtained in 18 cases. Forty-nine had type A and nine had type B of WPW. Forty-eight had permanent, four had alternant and six had no pre-excitation (PE) when they started the test. Mean maximal functional capacity, mean maximal heart rate and mean maximal double product were not different when compared to an age-matched control group. Of the 48 patients who began the test with PE, in 23 (48%) it disappeared while PE persisted in 25 (52%). In 16 cases the disappearance of the PE was sudden and in seven it was progressive. Pre-excitation persisted in 39.5% of patients with type A and in 88.8% with type B (p less than 0.01). ST-segment depression was observed in 76.6% of patients with PE and in 28.6% of cases without PE (p less than 0.01). ST-segment depression occurred in 44.8% of patients with type A and in 100% of cases with type B (p less than 0.05). Transient abnormal Thallium-201 scans were observed in 62.5% of patients without PE and in 20% with PE. No patients showed exertional arrhythmias. This study suggests the possibility of measuring the duration of the refractory period of the accessory pathway in those patients in which the PE disappears suddenly, at a given heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Effect of age on the solubility of volatile anesthetics in human tissues.

To determine the effect of age on the solubility of volatile anesthetics in human tissues, the authors measured the solubilities of isoflurane, enflurane, halothane, and methoxyflurane in vitro at 37 degrees C in 35 postmortem human tissue specimens. Specimens were taken from neonates, and young (20-50 yr), middle-aged (50-70 yr), and elderly adults (greater than 70 yr). Brain/gas, heart/gas, and liver/gas partition coefficients for all four anesthetics increased significantly (P less than 0.05) between birth and adulthood, although brain/gas partition coefficients in young adults tended to be higher than those in middle-aged and elderly adults. Heart/gas and liver/gas partition coefficients tended to increase with aging. Muscle/gas partition coefficients for the four anesthetics increased linearly with age. Fat/gas partition coefficients did not change significantly with age. Tissue/blood solubilities for the four anesthetics were of the same order of magnitude for a given tissue and age group. Tissue/blood solubilities for enflurane were 30% lower than those for isoflurane in the same tissue and age group. In summary: the solubility of volatile anesthetics in human tissues increases with age; the lower solubility of anesthetics in neonates partially explains the more rapid increase of alveolar and tissue anesthetic partial pressures in neonates; despite the higher blood solubility of enflurane, its lower tissue solubility may explain a rate of recovery comparable with that of isoflurane.

Adipose Tissue↗
PubMed1985

Lidocaine attenuates the intraocular pressure response to rapid intubation in children.

To determine the effect of intravenous lidocaine on the intraocular pressure (IOP) response to laryngoscopy and intubation, twenty unpremedicated children, ages one to ten years were studied. After administration of either intravenous sterile water (control) (n = 10) or preservative-free lidocaine (1.5 mg X kg-1) (n = 10), anaesthesia was induced with pancuronium (0.15 mg X kg-1), thiopentone (5 mg X kg-1), and atropine (0.02 mg X kg-1), and maintained with halothane, nitrous oxide and oxygen. The trachea was intubated one minute after administration of thiopentone. IOP (measured by applanation tonometry), heart rate, and systolic blood pressure were measured at the time of loss of the eyelid reflex (time 0), immediately after endotracheal intubation, and each minute thereafter for five minutes. In the control group, IOP increased (27 per cent) significantly after intubation (p less than 0.05), whereas in the lidocaine group, IOP did not increase (9.8 per cent) significantly after intubation. IOP decreased below time 0 values within three minutes after loss of the eyelid reflex in the lidocaine group (p less than 0.05). At each measurement (except time 0), IOP was significantly greater in the control group than in the lidocaine group (p less than 0.05). Heart rate and systolic blood pressure did not increase significantly in either group after intubation. We conclude that intravenous lidocaine (1.5 mg X kg-1) significantly attenuates the IOP response to laryngoscopy and intubation in children anaesthetized with pancuronium, thiopentone, and atropine.

Blood Pressure↗
PubMed1985

Anaesthetic considerations for separation of omphalo-ischiopagus tripus twins.

Anaesthesia for the separation of conjoined twins requires a multi-disciplinary team approach. We describe the anaesthetic management of a single-stage separation of 2 1/2-year-old omphalo-ischiopagus tripus conjoined twins. The successful 17 1/2-hour operation was conducted by five anaesthetists and 38 surgeons and nurses. Two major problems were encountered: massive blood loss in both twins (requiring transfusions of more than five and seven times their blood volumes) and a transient decrease in core temperatures after separation.

Adrenal Cortex Hormones↗