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Biomedical subjects

D R Jobes

Publications and source records attributed to D R Jobes.

At least 55 records · Page 3Linked to original sources
PubMed1981

Monitoring heparin anticoagulation and its neutralization.

Heparin anticoagulation and its neutralization were monitored by three different techniques: a manual protamine titration, an automated activated coagulation time, and an automated protamine titration. All three techniques provided satisfactory information. The decision of which to use must be based on other considerations such as available manpower and cost of equipment. The effect of using the automated protamine titration test on heparin and protamine requirements, and on blood loss measured intraoperatively after bypass and in overnight chest bottle drainage in two groups of comparable patients undergoing coronary artery bypass operation was studied. The heparin requirements were similar (24,420 +/- 584 units, control group; 23,550 +/- 849 units, treatment group), but the protamine requirements were markedly different (429 +/- 14.7 mg, control; 258 +/- 10.4 mg, treatment; p < 0.05). There was no statistical difference in intraoperative blood loss or overnight chest bottle drainage.

Autoanalysis↗
PubMed1981

CPR training.

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Education, Medical, Continuing↗
PubMed1981

Guide wires--a caution.

Popularity of the Seldinger technique of vascular cannulation has resulted in widespread use of spring guide wires. Though employed to make vascular cannulation easier and safer, guide wires are not without potential hazard. The review of guide wire design presented gives the operator an awareness of the potential problems inherent in their use. Three observed complications are described and suggestions are given for enhancement of utility and safety.

Catheterization↗
PubMed1981

Heparin rebound.

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Blood Coagulation Tests↗
PubMed1980

Continuous in-vivo blood-gas determination in man: reliability and safety of a new device.

The Sentorr is a gas chromatograph that monitors Pa2 and PaCO2 every 4 min from a probe placed through an intraarterial cannula. The accuracy of this device and complications resulting from its use were studied in 46 patients undergoing cardiac surgical procedures with oxygen to nitrous oxide-halothane anesthesia. Sentorr blood-gas values were compared with simultaneous samples analyzed with standard electrodes. During relatively steady states of respiration and circulation, and in the lower (50-125 torr) range of oxygen tensions, the measurements correlated closely (r = 0.92). The device also functioned well during low-flow states, but during hypothermic cardiopulmonary bypass, the correlation was only fair (r = 0.62). When nitrous oxide was present in the inspired gas, Sentorr PaO2 readings were a third lower than actual PO2 measurements, an effect corroborated by an in-vitro experiment. Directional changes of oxygen and carbon dioxide tensions were always correct in all situations. Placement of the probe in a radial artery was unsatisfactory because it significantly interfered with blood pressure measurement and resulted in inaccurate results for this patient population. The brachial artery was a satisfactory site for insertion, although attenuation of the arterial pressure tracing by the presence of a Sentorr probe resulted in systolic pressure readings that averaged 12 torr lower with mean arterial pressure readings 5 torr lower. No increase in morbidity due to use of a Sentorr probe for brachial arterial pressure monitoring could be identified. The most potentially serious complication encountered was transient loss of a palpable pulse without interruption of blood flow in one or more distal arteries after decannulation. This was observed in seven patients (four of whom had diminished distal pulses whith normal flow before cannulation).

Adult↗
PubMed1980

Peripheral vascular response to potassium administration during cardiopulmonary bypass.

Potassium (K+) is often administered to patients during cardiopulmonary bypass (CPB). The effects of rapid K+ administration during CPB were studied in 30 adult patients. Each patient received one bolus dose (2, 4, 8, 12, or 16 mEq) of potassium chloride (KCl) (2 mEq/ml) during CPB. Serum K+ was significantly increased from baseline values at KCl doses of 8 mEq and larger (p less than 0.05). All increases in serum K+ returned to clinically acceptable levels within 5 minutes after the bolus. Mean arterial pressure (MAP) (torr) and total peripheral resistance (TPR) (dynes sec cm-5) changes were biphasic; after an initial transient decrease, maximal with the 16 mEq K+ bolus (MAP -21 +/- 6, TPR - 315 +/- 135), these parameters increased (8 mEq K+ bolus, MAP + 15 +/- 16, TPR + 301 +/- 90; 12 mEq K+ bolus, MAP + 43 +/- 9, TPR + 998 +/- 250; 16 mEq bolus, MAP + 51 +/- 9, TPR + 1,216 +/- 120) with a peak at 3 minutes after the bolus. Hypertension, in nine of 18 patients receiving a KCl bolus of 8 mEq or larger, was of such magnitude (range 132 to 196 torr) as to require rapid therapeutic intervention to lower blood pressure. When KCl supplementation is required on CPB and slow infusion rates seem unreasonable, bolus doses of less than 8 mEq may be administered without vascular effect.

Adult↗
PubMed1977

Cerebral blood flow and metabolism during morphine--nitrous oxide anesthesia in man.

The effects of two levels of morphine-nitrous oxide anesthesia on cerebral blood flow (CBF) and cerebral metabolism (CMRO2) were measured in healthy male volunteers. CBF and metabolic measurements were made in the awake control state, after morphine, 1 mg/kg, with 70 per cent nitrous oxide and 30 per cent oxygen, and at a total dose of 3 mg/kg morphine with the same concentrations of nitrous oxide and oxygen. Ventilation was controlled and carbon dioxide added to inspired gas to maintain PaCO2 constant at 40 torr. CBF was 48.2 +/- 4.4 (SEM) ml/100 g/min during the control phase; 45.7 +/- 6.4 ml/100 g/min after 1 mg/kg morphine, and 44.3 +/- 4.9 ml/100 g/min after 3 mg/kg morphine. The latter values are not significantly different from control. Cerebral metabolic rates for oxygen, glucose, and lactate were normal in the control phase and did not change significantly when morphine was present at either level. It is concluded that morphine-nitrous oxide anesthesia produces no alteration of cerebral blood flow or metabolism in normal man at the two dose levels studies.

Anesthesia, General↗
PubMed1975

Effects of morphine-nitrous oxide anesthesia on cerebral autoregulation.

The effects of morphine-nitrous oxide anesthesia on cerebral autoregulation were studied in healthy male volunteers. Anesthesia was morphine, 2 mg/kg, and 70 per cent nitrous oxide in oxygen. Ventilation was controlled and carbon dioxide added to keep Paco-2 constant at 40 torr. Cerebral blood flow was measured first at the subject's normal mean arterial blood pressure, than at 60 torr and at 120 torr in a randomly assigned balanced order. Last, in five subjects cerebral blood flow was measured again at normal mean pressure. Blood pressure alteration was accomplished using phenylephrine or trimethaphan. Cerebral blood flow was 38.9 plus or minus 6.4 (SEM) ml/100 g/min at normal mean pressure, 49.5 plus or minus 10.7 ml/100 g/min at 60 torr. These values are not different a P IS LESS THAN 0.05. The data were analyzed for the possible effect of time on cerebral blood flow, and no change could be domonstrated. It is concluded that with Paco-2 constant at 40 torr morphine-nitrous oxide anesthesia does not significantly affect cerebral autoregulation in normal man.

Anesthesia, Inhalation↗