Anesthesia and analgesia
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Anesthesia and analgesia · Jun 1989
Intravenous magnesium sulfate inhibits catecholamine release associated with tracheal intubation.
The effects of pre-treatment with 60 mg/kg body weight magnesium sulfate intravenous on cardiovascular responses and catecholamine release associated with tracheal intubation were measured in 15 normal patients and in 15 saline solution pre-treated controls. Magnesium pre-treatment increased heart rate by 13 +/- 3.9 beats/minute. After intubation, heart rate was unchanged in the magnesium group at 107.3 +/- 3.6 beats/minute but increased in the control group to 120.9 +/- 4.6 beats/minute (P less than 0.05). ⋯ In controls, norepinephrine levels increased from 273.3 +/- 39.1 mg/ml to 944.6 +/- 68.7 pg/ml (P less than 0.05 for differences between groups). Epinephrine levels were unchanged from baseline after magnesium but in controls increased from 113.9 +/- 19.5 to 279.6 +/- 92.3 pg/ml (P less than 0.05). We conclude that magnesium sulfate attenuates the catecholamine mediated responses after tracheal intubation.
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Anesthesia and analgesia · Jun 1989
Maintenance of oxygenation during one-lung ventilation. Effect of intermittent reinflation of the collapsed lung with oxygen.
The aim of this study was to evaluate the effect on oxygenation of intermittent inflation with oxygen of the collapsed lung during one-lung ventilation (OLV). Sixteen patients were studied during pulmonary surgery. Balanced anesthesia with nitrous oxide and an inspired oxygen fraction of 0.5 was used. ⋯ PaO2 increased more than 4 kPa following each inflation in seven patients. In the eighth, PaO2 remained high throughout OLV. Although PaO2 decreased between inflations, it never reached the level observed in controls during 19 minutes of OLV.
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Anesthesia and analgesia · Jun 1989
Subclavian perivascular block: influence of location of paresthesia.
Subclavian perivascular block of the brachial plexus was used in 156 adult patients undergoing orthopedic hand and forearm surgery. The location of the elicited paresthesia prior to deposition of 30 ml of a solution containing 1% mepivacaine, 0.2% tetracaine and 1.200,000 epinephrine was recorded. Twenty minutes later the quality of the block in the distribution of the superior, middle and inferior trunks of the brachial plexus was evaluated. ⋯ A superior trunk paresthesia was the paresthesia most often elicited. It resulted in a significantly lower incidence of inferior trunk anesthesia than did a middle or inferior trunk paresthesia. Complications included arterial puncture (25.6%), Horner's syndrome (64.1%), and recurrent laryngeal nerve block (1.3%), with no instances of symptomatic phrenic block or symptomatic pneumothorax.
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Anesthesia and analgesia · Jun 1989
Comparative Study Clinical Trial Controlled Clinical TrialTetanic fade following administration of nondepolarizing neuromuscular blocking drugs.
Fade in response to tetanic stimulation was studied following administration of atracurium 120 or 225 micrograms/kg, vecuronium 23 or 40 micrograms/kg, pancuronium 30 or 60 micrograms/kg, or d-tubocurarine 185 or 450 micrograms/kg. Ten patients received each dose and tetanic fade was measured at maximum block in the patients, who received the lower doses of the relaxants or at 10% recovery in those who received the higher doses. Fade during tetanic stimulation was generally similar in all the groups with the exception of the higher dose of pancuronium which showed a significantly greater fade in comparison with the higher doses of atracurium and d-tubocurarine. If fade in response to tetanic stimulation represents a prejunctional effect, the results from the present study suggest that neuromuscular blocking drugs cannot be differentiated with respect to their relative prejunctional effects by measurement of tetanic fade during established block after administration of clinically useful doses as used in the present study.
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The wall temperatures of the absorptive chambers of a divided soda lime canister were measured in 70 patients to determine the relationship between the difference in temperature of the two chambers and CO2 passage through the first chamber. CO2 passage through the first chamber was detected when the temperature of the second chamber became equal to that of the first. ⋯ When the maximal absorptive capacity of soda lime was reached, the pH of the surface of soda lime granules was still too high to change the indicator color. Exhaustion of soda lime is more reliably recognized by measuring wall temperatures of the chambers than by observing color change of the soda lime granules.