Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2002
Prolonged neuromuscular block after rocuronium in postpartum patients.
Postpartum patients have not completely lost the weight gained during pregnancy. Drug dosing according to total body weight (TBW) can cause exaggerated effects and dosing by lean body mass (LBM) may provide a more consistent response despite the increased weight. We compared the duration of a rocuronium neuromuscular block in 22 women undergoing postpartum tubal ligation 31--79 h after delivery, with that in 22 women undergoing gynecological surgery. Anesthesia was induced and maintained with propofol and alfentanil. Half of the patients in each of the Postpartum and Control groups received a bolus dose of rocuronium 0.6 mg/kg TBW and the remaining half received rocuronium 0.6 mg/kg LBM. Neuromuscular block was monitored by electromyography and the ulnar nerve was stimulated transcutaneously using a train-of-four pattern. When rocuronium was given by TBW, median (range) duration of neuromuscular block until 25% recovery of the first twitch response was longer in the Postpartum group, 35.3 (29.7--48.7) min, compared with the Control group, 24.8 (21.5--28.6) min (P < 0.001). After dosing by LBM, the duration of block was similar between groups. The prolonged block with rocuronium in the Postpartum patients can be explained by relative drug overdose when dose calculation is based on their temporarily increased body weight. ⋯ Neuromuscular block is prolonged in the postpartum period after standard doses of rocuronium. Drug administration according to lean body mass will produce a more consistent duration of block.
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Anesthesia and analgesia · Mar 2002
Spinal cord stimulation in postherpetic neuralgia and in acute herpes zoster pain.
We studied the effects of spinal cord stimulation (SCS) on postherpetic neuralgia (PHN). Data of 28 patients were prospectively investigated over a median period of 29 (quartiles 9--39) mo. In addition, four patients with acute herpes zoster (HZ) pain were studied simultaneously. After intractable pain for more than 2 yr, long-term pain relief was achieved in 23 (82%) PHN patients (median, 70 yr) during SCS treatment confirmed by a median decrease from 9 to 1 on the visual analog scale (P < 0.001). In five cases with serious comorbidity, the initial pain alleviation could not be stabilized. Spontaneous improvement was always confirmed or excluded by SCS inactivation tests at quarterly intervals. Eight patients discontinued SCS permanently because of complete pain relief after stimulation periods of 3--66 mo, whereas 2 reestablished SCS because of recrudescence after 2 and 6 mo. Considerable impairments in everyday life, objectified by the pain disability index, were also significantly improved (P < 0.001). In 4 patients with acute HZ pain, SCS was promptly effective and after periods of 2.5 (quartiles 2--3) months the pain had subsided. SCS seems to offer a therapeutic option for pharmacological nonresponders. ⋯ In many patients with postherpetic neuralgia and acute herpes zoster pain is not satisfactorily alleviated with pharmacological approaches. We report on 23 of 28 patients with postherpetic neuralgia and 4 of 4 with acute herpes zoster whose chronic pain was improved by electrical spinal cord stimulation.
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Anesthesia and analgesia · Mar 2002
A streamlined pharynx airway liner: a pilot study in 22 patients in controlled and spontaneous ventilation.
An inexpensive, single-use alternative device to the laryngeal mask and cuffed oropharyngeal airway appears useful in controlled and spontaneous ventilation. The hollow soft plastic airway may act as a sump for pooled secretions, possibly minimizing regurgitation risks. Without a cuff, important cost savings are likely.
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Anesthesia and analgesia · Mar 2002
Hydroxyethyl starch in balanced electrolyte solution (Hextend)--pharmacokinetic and pharmacodynamic profiles in healthy volunteers.
Hextend is a new plasma volume expander containing 6% hydroxyethyl starch (HES) in a physiologically balanced medium of electrolytes, glucose, and lactate (weight average, molecular weight 670 kDa, molar substitution 0.75). This open-label study was designed to investigate the pharmacokinetic and pharmacodynamic profiles of Hextend in 21 healthy volunteers. We infused Hextend 10 ml/kg IV over 20 min and determined serum concentrations of HES at selected intervals over a 7-day period. Serum concentration-time curves indicated mixed pharmacokinetic behavior reflecting a two-compartment model in most subjects. The median serum half-life over 7 days was 38.2 h. The balanced formulation of the suspension medium did not seem to affect distribution, metabolism, or excretion of Hextend when compared with similar HES. Pharmacodynamic analysis demonstrated decreases in some plasma components compatible with the infusion of that volume of fluid and the duration of plasma volume expansion. Other plasma components remained unchanged, reflecting the benefit of a balanced electrolyte solution. Hemodilution was observed for 24--48 h after short-term infusion of Hextend. Some hemostatic indices showed moderate changes, and serum amylase demonstrated a temporary increase. Our study suggested that Hextend has pharmacokinetic and pharmacodynamic profiles that are similar to those of other HES. ⋯ Hextend is a new plasma volume expander containing 6% hydroxyethyl starch in a physiologically balanced medium. This open-label volunteer study demonstrated that it has pharmacokinetic and pharmacodynamic profiles similar to those of established HES.