Anesthesia and analgesia
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Anesthesia and analgesia · Jan 1996
Randomized Controlled Trial Comparative Study Clinical TrialInfluence and relative sensitivities of 50-Hz and 100-Hz tetanic stimuli on subsequent tetanic fade ratios in patients receiving vecuronium.
We studied the possible effects of repetitive (1-min interval) 50- and 100-Hz tetanic stimuli on 50-Hz and 100-Hz tetanic fade ratios (RF50HZ and RF100HZ). We also evaluated the sensitivity of the recorded responses to these two tests to assess residual neuromuscular block (isometric adductor pollicis mechanical activity), either during spontaneous recovery, or 15 min after neostigmine administration, in 22 adult anesthetized (thiopental, fentanyl, N2O/O2) patients receiving vecuronium. Two 50-Hz and two 100-Hz, 5-s duration, tetanic stimulations were randomly assessed at 1-min intervals: in a spontaneous (SPO) group (n = 11), when train-of-four (TOF) ratio spontaneously regained 0.7, and in a neostigmine (NEO) group (n = 11), 15 min after 40 micrograms/kg neostigmine was given intravenously at 25% return of control twitch tension. ⋯ In the NEO group, when TOF ratio was approximately 0.9, RF50HZ was 0.93 +/- 0.01 before and after subsequent tetanic stimulation, while RF100HZ was 0.80 +/- 0.02 and 0.78 +/- 0.02, respectively (NS). From patient to patient, both RF50HZ and RF100HZ were also identical. In conclusion, in patients receiving vecuronium, 1) 5-s, 50- and 100-Hz tetanic stimuli may be repeated without changes at 1-min intervals and, 2) in contrast to RF50HZ, recorded RF100HZ enables one to determine residual neuromuscular block during spontaneous recovery (P < 0.001) such as after neostigmine reversal (P < 0.05).
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Anesthesia and analgesia · Jan 1996
Clinical Trial Controlled Clinical TrialPositive pressure ventilation with the laryngeal mask airway in children.
We studied the safety of positive pressure ventilation (PPV) when using the size 2 laryngeal mask airway (LMA) in 46 ASA physical status I or II children (aged 38 +/- 21 mo) undergoing elective surgery. The LMA cuff was inflated in incremental steps to achieve a cuff leak pressure > or = 15 cm H2O. Abdominal circumference was measured before and after PPV in study patients, as well as in a control group managed with tracheal intubation. ⋯ Mild gastric distention often occurs. The risk of clinically significant gastric distention appears to be small, but it warrants close monitoring. We conclude that with certain precautions described in the text, the size 2 LMA provides a relatively safe airway for PPV in children.
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Anesthesia and analgesia · Jan 1996
Comparative StudyFactors associated with excessive postoperative blood loss and hemostatic transfusion requirements: a multivariate analysis in cardiac surgical patients.
The purpose of this study was to prospectively evaluate whether heparin and protamine doses administered using a standardized protocol based on body weight and activated clotting time values are associated with either transfusion of hemostatic blood products (HBPs) or excessive postoperative bleeding. Analysis using 10 multiple logistic or linear regression models in 487 cardiac surgical patients included perioperative variables that may have an association with either transfusion of HBP and/or excessive postoperative chest tube drainage (CTD). ⋯ Preoperative use of warfarin or heparin was not associated with excessive blood loss of perioperative transfusion of HBPs. In contrast to previous studies using bovine heparin, data from the present study do not support the use of reduced doses of porcine heparin during CPB.
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Anesthesia and analgesia · Jan 1996
Comparative Study Clinical TrialNeostigmine reversal of vecuronium neuromuscular block and the influence of renal failure.
The duration of clinical relaxation induced by vecuronium and reversal by neostigmine was studied in 40 patients with renal failure (RF) and 40 patients with normal renal function (NL) under general anesthesia. Patients were premedicated with flunitrazepam, and anesthesia commenced with fentanyl 1-2 micrograms/kg, thiopental 5-8 mg/kg, and vecuronium 0.1 mg/kg. Anesthesia was maintained with 60% nitrous oxide in oxygen, isoflurane 0.3%-1.0% end-tidal concentration, and 1 microgram/kg fentanyl every 20-30 min. ⋯ Spontaneous recovery time, reversal time, and the time to recovery of TOF ratio to 0.7 were recorded. RF did not prolong the vecuronium neuromuscular blocking effect, reversal was achieved at the same rate in NL as in RF, and the duration of reversal of neuromuscular blocking effect of vecuronium was not influenced by the time of administration of neostigmine. Therefore, the neuromuscular blocking effect of a tracheal intubating dose of vecuronium can be reversed at the same rate in patients with end-stage RF as in patients with normal kidney function.
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Anesthesia and analgesia · Jan 1996
Comparative Study Clinical TrialEpiduroscopic changes in patients undergoing single and repeated epidural injections.
Using a superfine fiberscope with an outer diameter of 0.75 mm, the effect of repeated injections through a single epidural catheter on the epidural space was examined in 18 patients. The subjects were divided into a control group of 10 patients who had not previously received epidural anesthesia (EA) and an EA group of 8 patients who had received repeated EA with 4-6 mL 0.25% bupivacaine through an epidural catheter, two to three times per day for 7-14 days. The epidural space was observed through a fiberscope passed through a 17-gauge Tuohy needle. ⋯ Five patients in the EA group experienced pain when the fiberscope was inserted into the epidural space. These investigations show that continuous EA might be followed by a high incidence of nonspecific epidural changes. Superfine fiberscope may be useful in the detection or diagnosis of local epidural reaction.