Anesthesia and analgesia
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Anesthesia and analgesia · Feb 1988
Systolic pressure variation is greater during hemorrhage than during sodium nitroprusside-induced hypotension in ventilated dogs.
The systolic pressure variation (SPV), which is the difference between the maximal and minimal values of the systolic blood pressure (SBP) after one positive-pressure breath, was studied in ventilated dogs subjected to hypotension. Mean arterial pressure was decreased to 50 mm Hg for 30 minutes either by hemorrhage (HEM, n = 7) or by continuous infusion of sodium nitroprusside (SNP, n = 7). During HEM-induced hypotension the cardiac output was significantly lower and systemic vascular resistance higher compared with that in the SNP group. ⋯ The delta down, which is the measure of decrease of SBP after a mechanical breath, was 20.3 +/- 8.4 and 10.1 +/- 3.8 mm Hg in the HEM and SNP groups, respectively, during hypotension (P less than 0.02). It is concluded that increases in the SPV and the delta down are characteristic of a hypotensive state due to a predominant decrease in preload. They are thus more important during absolute hypovolemia than during deliberate hypotension.
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Anesthesia and analgesia · Jan 1988
Comparative Study Clinical Trial Controlled Clinical TrialRapid administration of a narcotic and neuromuscular blocker: a hemodynamic comparison of fentanyl, sufentanil, pancuronium, and vecuronium.
High-dose narcotic anesthetic inductions usually avoid circulatory depression better than do other techniques; however, the selection of a narcotic and neuromuscular blocker influences subsequent hemodynamic responses. One hundred-one patients having aortocoronary bypass graft (CABG) surgery were investigated using four combinations of a narcotic and neuromuscular blocker: group FP (fentanyl 50 micrograms/kg, pancuronium 100 micrograms/kg); group FV (fentanyl 50 micrograms/kg, vecuronium 80 micrograms/kg); group SP (sufentanil 10 micrograms/kg, pancuronium 100 micrograms/kg); and group SV (sufentanil 10 micrograms/kg, vecuronium 80 micrograms/kg), each combination being administered over 2 minutes. Hemodynamic functions were then monitored for 10 minutes before tracheal intubation. ⋯ Cardiac arrhythmia occurred most often in group SP; only in group FP were there no arrhythmias, ischemic changes, or hemodynamic disturbances requiring intervention. Time to onset of neuromuscular blockade did not differ among the four groups, but transient chest wall rigidity occurred significantly more often with sufentanil than with fentanyl. Overall, the fentanyl/pancuronium combination afforded the greatest hemodynamic stability, whereas the sufentanil/vecuronium combination proved least satisfactory because of bradycardia and hypotension, requiring treatment in 35% of group SV patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Jan 1988
Randomized Controlled Trial Comparative Study Clinical TrialComparison of bupivacaine and alkalinized bupivacaine in brachial plexus anesthesia.
To define the effect of alkalinization of bupivacaine 0.5% in subclavian perivascular brachial plexus blockade, the time to onset, time to peak effect, and 6-hour regression of sensory and motor blockade were determined. Sixty physical status ASA I and II patients were randomly allocated to one of two groups and a double-blind design was used: group I (n = 30) received bupivacaine 0.5% (pH, 5.5) 3 mg/kg, while group II (n = 30) received alkalinized bupivacaine 0.5% (pH, 7.05-7.15) 3 mg/kg. Onset and regression of sensory blockade were determined by pinprick in the C4-T2 skin dermatomes, while motor blockade was assessed using a scheme of proximal to distal muscle group paralysis. ⋯ Similarly, no difference in time to onset of motor blockade (group I, 6.9 +/- 1.7 min; group II, 6.3 +/- 1.5 min) or time to peak motor effect (group I, 18.1 +/- 1.9 min; group II, 15.1 +/- 1.9 min) was observed. Regression of postoperative sensory and motor blockade was similar in both groups. It is concluded that alkalinization of bupivacaine 0.5% solutions does not confer any added clinical advantage in subclavian perivascular brachial plexus blockade when compared with commercially available bupivacaine.