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Biomedical subjects

R E Johnstone

Publications and source records attributed to R E Johnstone.

At least 19 recordsLinked to original sources
PubMed1992

Pocket computers in anesthesiology.

Pocket computers are a new technology in academic anesthesia practice. These computers are inexpensive, portable, easy to use and can store large amounts of data, but the limited ability to program them and the length of time necessary to enter data can be disadvantages.

Anesthesiology↗
PubMed1976

Effect of halothane anesthesia on muscle, liver, thyroid, and adrenal-function tests in man.

Seven healthy men volunteers received 6.6 +/- 1.3 (SD) percent-hours of halothane oxygen anesthesia without surgery. Serum bilirubin, alanine aminotransferase, and aspartate aminotransferase significantly increased after anesthesia, which may indicate subclinical liver-cell damage. Creatine kinase of skeletal muscle origin increased above 90 U/liter in six subjects, indicating subclinical muscle-cell damage. Cortisol, triiodothyronine uptake, thyroxine, and free thyroxine index increased significantly immediately after anesthesia. Serum bromide concentrations had increased by fivefold on the second day after anesthesia, and on the ninth day was still elevated fourfold. Oral temperatures increased 0.7 degrees C 6 h post-anesthesia, possibly because of increased thyroxine activity. Lactate dehydrogenase, hydroxybutyrate dehydrogenase and gamma-glutamyltransferase activities did not change significantly. No drugs administered during the course of this study chemically interfered with any of the test methods used.

Adrenal Glands↗
PubMed1975

Letter: Fire hazard.

Explore the source record for details and available documents.

Anti-Infective Agents, Local↗
PubMed1975

Increased serum bromide concentration after halothane anesthesia in man.

Seven healthy male volunteers received 6.6 plus or minus 0.5 (SE) per cent-hours of halothane-oxygen anesthesia without surgery. Serum bromide concentrations increased from 0.6 plus or minus 0.1 before anesthesia to 2.9 plus or minus 0.2 mEq/l on the second day after anesthesia. On the ninth day serum bromide was still elevated to 2.5 plus or minus 0.1 mEq/l. These bromide concentrations represent psychoactive levels and may account for previously recognized prolonged changes in mood and intellectual function after halothane. Plasma and urinary fluoride concentrations did not increase significantly.

Adult↗
PubMed1975

Combination of delta9-tetrahydrocannabinol with oxymorphone or pentobarbital: Effects on ventilatory control and cardiovascular dynamics.

Marijuana is widely used, yet few data concerning its actions combined with other drugs exist. Psychologic, respiratory and cardiovascular effects of delta9-tetrahydrocannabinol (THC), the active component of marijuana, combined with oxymorphone (OXM) or with pentobarbital (PBL), were studies in 15 healthy volunteers. Oxymorphone, 1.0 mg/70 kg, iv, caused sedation and ventilatory depression (minute ventilation: 24.9 plus or minus 11.9 SD to 14.1 plus or minus 4.9 1/min with PETCO2 held at 50 torr) in eight volunteers. TCH (27, 40, 60, 90, and 134 mug/kg, iv) increased sedation and further decreased ventilation with each TCH dose to 6.6 plus or minus 3.7 1/min after 134 mug/kg. The combination of OXM and THC decreased the CO2-ventilation slope from 2.23 to 0.88 1/min/torr. When THC, 134 mug/kg, was added to OXM, which alone caused no significant cardiovascular change, cardiac index (4.1 plus or minus 1.3 to 5.0 plus or minus 2.2 1/min/m-2) and heart rate (66 plus or minus 12 to 107 plus or minus 31 beats/min) significantly increased and total peripheral resistance (1,030 plus or minus 260 to 660 plus or minus 200 dynes-sec/cm-5) decreased. Heart rates exceeded 150 beats/min in two subjects after 27 and 134 mug/kg THC. Pentobarbital alone, 100 mg/70 kg, iv, caused no significant ventilatory or cardiovascular change. THC, after PBL pretreatment, induced hallucinations and anxiety in five of seven volunteers; four failed to complete all five doses of THC becuase of the severe psychologic effects. The combination of PBL and 40 to 134 mug/kg THC did not affect ventilation significantly. After PBL pretreatment, THC significantly increased heart rate (76 plus or minus 17 to 130 plus or minus 32 beats/min). Cardiac index also increased (3.8 plus or minus 0.8 to 5.6 plus or minus 1.9 1/min/m-2) and total peripheral resistance decreased (1,070 plus or minus 240 to 720 plus or minus 300 dynes-sec/cm-5). Three subjects developed heart rates esceeding 150 beats/min after 27, 27, and 90 mug/kg THC; in all three, heart rates fell from maximal value with a further dose of THC.

Adult↗
PubMed1975

Intravenous delta9-Tetrahydrocannabinol: Effects of ventilatory control and cardiovascular dynamics.

Delta9-Tetrahydrocannabinol (THC), the active component of marijuana, was studies to determine whether it might be useful for preanesthetic medication. Ten healthy subjects received THC intravenously in logarithmically spaced incremental doses. Four subjects received a total cumulatine dose of 135 mug/kg and four others, 201 mug/kg, Two of the ten subjects discontinued the study because of anxiety reactions. Ventilatory minute volume at a controlled elevated CO2 tension, 48 plus or minus 2 (SD) torr, changed minimally with TCH, -0.49 1/min/50 per cent increase in dose. TCH shifted the ventilatory response to CO22.7 torr destrad at 20 1/min without a change in slope. Dose-related tachycardia was the most marked cardiovascular effect. Heart rates increased to more than 100/min in five of six subjects. Cardiac index increased from 4.04 plus or minus 0.62 1/min/m-2 before TCH to 6.92 plus or minus 2.34 1/min/m-2 after 134 mug/kg. Mean arterial pressure increased slightly, and total peripheral resistance fell. The cardiovascular changes suggest beta-adrenergic stimulation. Intense mental effects and anxiety prohibited higher THC doses.

Adult↗