Anesthesia and analgesia
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Ultratherm Infusion Fluid Warmer Model 3703-1 (Ultratherm) is a disposable device approved by the Food and Drug Administration to warm fluids including blood and nutritional fluids. It has no temperature monitor or audible alarm and uses air-activated chemical heating elements in direct contact with loops of intravenous (i.v.) tubing. We studied the warming of blood and saline by Ultratherm using intratubing thermocouple wire probes. ⋯ At flow rates of 500, 100, and 30 mL/h, room temperature saline reached 34 degrees C, 45 degrees C, and 52 degrees C, respectively. The unmonitored, high, internal warmer chamber temperatures preclude the use of Ultratherm with blood or any fluids potentially damaged by excessive heat, and its use should be limited strictly to clear fluids. The utility of the warmer, even with clear fluids, is further limited to room temperature fluids, to a time interval between 1 and 6 h following activation, and to flow rates between 100 and 500 mL/h.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Dec 1993
Pharmacokinetics and pharmacodynamics of pipecuronium in patients with cirrhosis.
To determine the effect of liver cirrhosis on the pharmacokinetics and pharmacodynamics of pipecuronium, the authors administered 100 micrograms/kg of pipecuronium intravenously to eight patients with liver cirrhosis and eight patients with normal liver and renal function undergoing elective abdominal surgery. All patients were anesthetized with thiopental (5-7 mg/kg), nitrous oxide (50-70% in oxygen), and fentanyl in repeated doses (2 micrograms/kg). Plasma concentrations of pipecuronium were determined by high-pressure liquid chromatography. ⋯ The onset of neuromuscular blocking effect was longer in cirrhotics (233 +/- 112 s) (P < 0.05) than in controls (170 +/- 33 s). The clinical duration (injection until single twitch returned to 25%) was similar between the two groups: 167 +/- 41 min in controls and 165 +/- 48 min in cirrhotics. The authors conclude that hepatic insufficiency due to cirrhosis does not alter the pharmacokinetics and pharmacodynamics of pipecuronium (100 micrograms/kg).
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Anesthesia and analgesia · Dec 1993
Randomized Controlled Trial Clinical TrialPostoperative pain: the effect of low-dose ketamine in addition to general anesthesia.
In a randomized, double-blind study, postoperative pain was assessed in 22 patients undergoing elective open cholecystectomy with two types of anesthesia: standardized general anesthesia (control group), and low-dose ketamine as an addition to the same method of general anesthesia, before surgical incision (ketamine group). After the operation we found that the time from the end of surgery to the first request for analgesic was longer in the ketamine group. Postoperatively, patients in both groups were treated with patient-controlled analgesia (PCA) in exactly the same way. ⋯ The mean dose of morphine given in patients of the control group during the first 24 h was 48.7 mg vs 29.5 mg in the ketamine group. Mean visual analog scale (VAS) and verbal rating scale (VRS) were higher in patients in the control group during the first 5 h after surgery (P < 0.02), but between 5 and 24 h after surgery VAS and VRS were not significantly different (P > 0.05). Our results indicate that postoperative pain can be decreased when ketamine in low doses is added to general anesthesia before surgical stimulation.
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Anesthesia and analgesia · Dec 1993
Randomized Controlled Trial Clinical TrialRegression of sensory anesthesia during continuous epidural infusions of bupivacaine and opioid for total knee replacement.
The epidural administration of morphine and fentanyl delay the regression of sensory anesthesia in postoperative patients receiving epidural bupivacaine. This study was performed to determine any differential effects of two lipid-soluble opioids upon regression of sensory anesthesia during coadministration with epidural bupivacaine. Forty-eight patients scheduled for total knee replacement underwent lumbar epidural catheterization and received 1.5% etidocaine with 1:200,000 epinephrine to establish sensory anesthesia to approximately T6 bilaterally. ⋯ For each patient, the study was considered terminated when the cephalad level of sensory anesthesia bilaterally decreased five dermatomal segments or the pain score reached "5" (moderate pain). Patients receiving epidural infusions of bupivacaine and meperidine had a significantly slower regression of sensory anesthesia and slower development of pain. There was no difference in the rate of regression of sensory anesthesia or the development of pain among patients receiving bupivacaine alone or bupivacaine with fentanyl.
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Anesthesia and analgesia · Dec 1993
The resting volume and compliance characteristics of the bronchial cuff of left polyvinyl chloride double-lumen endobronchial tubes.
The resting volume of a low-pressure, high-volume cuff is an important factor that determines the cuff compliance, because it is the maximum volume that maintains the low-pressure characteristics of the cuff. Modern polyvinyl chloride (PVC) double-lumen tubes (DLT) are designed with a low-pressure bronchial cuff to minimize the risk of bronchial damage. Maintenance of the low-pressure characteristics of this cuff, however, requires knowledge of how its resting volume and compliance vary between different DLT sizes and brands, and how the compliance changes when the cuff is inflated inside different-sized bronchi. ⋯ The compliance of each cuff was characterized by: 1) the cuff resting volume, defined as the smallest cuff volume beyond which a 0.5-mL increase in volume resulted in more than 10 mm Hg increase in cuff pressure; and 2) the cuff pressure at 3-mL volume. Measurements were repeated for sizes 35 Fr and 41 Fr left Mallinckrodt DLTs with the bronchial cuff lying inside two canine left main-stem bronchi measuring 11 mm and 13 mm in diameter. The bronchial cuff resting volume ranged from 1.5 to 5.0 mL in different sizes and brands of DLTs, which could be explained by differences in cuff size between different manufacturers and between different DLT sizes of the same manufacturer.(ABSTRACT TRUNCATED AT 250 WORDS)