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Biomedical subjects

G M Aasheim

Publications and source records attributed to G M Aasheim.

7 recordsLinked to original sources
PubMed1978

Sequence of return of neurological function and criteria for safe ambulation following subarachnoid block (spinal anaesthetic).

Twenty-three adult men were studied during and after subarachnoid block anaesthesia for elective surgery. Measurements were obtained of mean arterial pressure and pulse, both supine and after standing for five minutes, core body (tympanic) and peripheral skin (toe) temperatures and blood flow in the leg. Time of measurements included one hour after the injection of tetracaine and after regression of the block. Results obtained indicate that the sequence of return of neurological activity following tetracaine subarachnoid block is sympathetic nervous system activity, pinprick sensation, somatic motor function followed by proprioception in the feet. This progression provides the basis for recommended criteria which indicate when it is safe for patients who have been subarachnoid block anaesthesia to become ambulatory. These criteria include: (1) return of pinprick sensation in the peri-anal area (sacral 4--5); (2) plantar flexion of the foot (while supine) at pre-anaesthetic levels of strength; and (3) return of proprioception in the big toe, always provided that the patient is not hypovolaemic or sedated.

Adult↗
PubMed1978

Prevention of post-anaesthesia shivering.

This study involves ventilation of the lungs with warmed humidifed anaesthetic gases during prolonged elective abdominal operations. Tympanic, oesophageal and toe temperatures were compared bewteen twenty warmed and twenty un-warmed patients at various times during operation and recovery. Fifty per cent (10/20) unwarmed patients shivered in the recovery room, while none of the warmed patients shivered. Our data indicate that pulmonary ventilation with warm humidified anaesthetic gases provides heat transfer by the lungs, preventing hypothermia during operation and post -anaesthesia shivering is prevented by maintaining the patient normothermic in both the operating room and the recovery room.

Anesthesia, General↗
PubMed1978

Neural pharmacokinetics of epinephrine.

The effects of 3H-epinephrine on the duration of block and on the time course of uptake and efflux of local anesthetic (14C-lidocaine hydrochloride) were determined in the infraorbital nerve of the pentobarbital-obtunded rat. Epinephrine, 1:50,000, doubled the duration of behavioral block produced by 37 mM (1 per cent) lidocaine; 1:100,000, 1:200,000 and 1:400,000 prolonged the block correspondingly less, the relation being inversely proportional to the log of the epinephrine concentration. The nerural level of 3H-epinephrine reached a peak within 10 minutes and then declined linearly with time, as did the associated neural level of 14C-lidocaine. Linearity apparently results from the summation of the time-linked decreasing diffusion gradient of drug and the consequently increasing rate of perfusion with blood. Phentolamine antagonizes the epinephrine-caused prolongation of behavioral block. The results suggest that in spinal anesthesia the extent of dilution of an epinephrine additive by cerebrospinal fluid will significantly affect the duration of the block.

Anesthesia, Local↗
PubMedDate not supplied

Spinal anesthesia: bupivacaine versus tetracaine.

The clinical effects of equal hyperbaric doses of bupivacaine HCl and tetracaine HCl were studied and compared in 99 adult men undergoing spinal anesthesia for similar surgical procedures. The spinal anesthetic agents were used in random order in various dosages. Comparisons were made of (1) amount of anesthetic agent used, (2) elapsed time for onset of analgesia, (3) elapsed time for obtaining maximum anesthesia, (4) cephalad dermatome level of anesthesia, (5) incidence of motor blockade, and (6) duration of anesthesia. Results with the 2 drugs in equal dose, volume, and specific gravity were almost identical. However, tetracaine provided a motor block in a significantly greater number of patients than did pubivacaine (100 versus 42%, rho less than 0.001) when both drugs were used at the 9.75-mg dose level.

Anesthesia, Spinal↗
PubMedDate not supplied

Early reversal of postoperative hypoxemia.

Peridural analgesia was combined with the respiratory-stimulant effect of doxapram for intermittent hyperinflation of the lungs to reverse early postoperative (PO) hypoxemia following inhalation anesthesia for upper abdominal operations. Twenty unpremedicated men undergoing upper abdominal operations were studied for 5 hours in the recovery room. Ten of these patients received doxapram plus peridural analgesia; the other 10, doxapram plus morphine analgesia. Rectal temperature, PaO2, PaCO2, respiratory rate, exhaled minute ventilation (VE), tidal volume (VT), and blood pressure and pulse were measured. The mean increase from control for VE was 9.6 L/min and for VT, 356 ml/breath during doxapram therapy for the morphine group. Corresponding values for the peridural group were 14.4 L/min for VE and 660 ml/breath for VT. Mean PaO2 for the morphine group decreased significantly from the corresponding preoperative value (p less than 0.005). Lack of significant change between preoperative and PO values for PaO2 for the peridural group would indicate that under the conditions of this study, early PO hypoxemia can be reversed by the combination of peridural analgesia with doxapram therapy.

Adult↗