Anesthesia and analgesia
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In this study we sought to determine the factors influencing red blood cell (RBC) transfusions and to study the transfusion practice of anesthesiologists during liver transplants. A retrospective study of 206 successive liver transplants was undertaken during a period of 52 mo. Transfused blood products were identified. Twenty variables were analyzed in a univariate fashion. For the multivariate analysis, the cases were divided in 2 subgroups: more than 4 RBC units transfused and 4 or less RBC units transfused. The average number of RBC units transfused during a liver transplant was 2.8 (+/- 3.5) per patient, 32.0% did not receive any RBC, and 19.4% did not receive any blood products during the transplant. Three variables were related to the number of RBC units transfused: the starting International Normalized Ratio value, the starting platelet count, and the duration of surgery. We found that there was a wide difference in the transfusion practice of the anesthesiologists involved in this series of liver transplants. It was difficult to identify predictive factors for RBC transfusions when the transfusion rate was small and because of the variability in human factors. Plasma transfusion did not decrease the rate of RBC transfusions; sometimes it was the contrary. ⋯ This is a retrospective study of 206 liver transplants over 52 mo to identify the predictive factors of red blood cell transfusions and the anesthesiologists' transfusion strategies. We conclude that there is a wide difference in transfusion practices among anesthesiologists.
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Anesthesia and analgesia · May 2004
Case ReportsTransient vascular insufficiency after axillary brachial plexus block in a child.
Axillary block is used in children for procedures on the hand and forearm. We report on a child with an amputation of the thumb in whom an axillary block was given, after which the limb became pale and pulseless. The pulses returned spontaneously in 15 min. The awareness of this possibility and chances of spontaneous recovery should be considered. ⋯ Transient vascular insufficiency of the upper limb may happen as a rare complication after axillary block. Knowledge of this complication can help the anesthesiologist in the management of this problem.
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Anesthesia and analgesia · May 2004
Case ReportsTracheal ring fracture during a PercuTwist tracheostomy procedure.
Because of difficult weaning from mechanical ventilation, a 59-yr-old man admitted for emergency cardiac surgery underwent a bedside PercuTwist tracheostomy on day 14 of his intensive care unit stay. We observed a double fracture of the second tracheal ring during the initial dilation process with the PercuTwist dilator, associated with distal migration of a cartilage fragment, which was avulsed from the anterior portion of the second cartilaginous ring. ⋯ Like other antegrade single-step techniques, the PercuTwist tracheostomy presents the risk of anterior tracheal wall damage during the initial stage of the dilation process. Antegrade forces applied to the trachea should be minimized by sufficiently deep skin incision and both slow and smooth initial rotation of the dilator.
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Anesthesia and analgesia · May 2004
Intratracheal application of recombinant surfactant protein-C surfactant to rabbits attenuates acute lung injury induced by intratracheal acidified infant formula.
Our aim in the current study was to determine whether recombinant surfactant protein-C (rSP-C) surfactant improves acute lung injury (ALI) induced by intratracheal acidified milk products. Twenty-eight rabbits were randomly divided into four groups. ALI was induced with intratracheal acidified infant formula (0.8 mL/kg, pH 1.8) in 3 groups. The control group received intratracheal acidified saline. Therapy groups received 1 of 2 doses of intratracheal rSP-C surfactant (0.5 or 2 SP-C mg/kg) 30 min after the acidified infant formula. The lungs were ventilated with 100% oxygen for 4 h after induction of ALI. Acidified infant formula dramatically reduced oxygenation and lung compliance, and increased resistance. Both doses of rSP-C improved the variables [mean PaO(2) (mm Hg) and compliance (mL/cm H(2)O) at 4 h: 61 and 0.4 for infant formula, 162 and 1.0 for small-dose rSP-C, and 152 and 1.2 for large-dose rSP-C, respectively; P < 0.05]. Pulmonary leukosequestration and edema, and severe morphological changes were attenuated by rSP-C treatment (ALI score: 14, 7, 7 in infant formula, small-dose rSP-C, and large-dose rSP-C; P < 0.05). The efficacy was similar for the two doses of rSP-C. These findings suggest that intratracheal administration of rSP-C ameliorates ALI induced by aspiration of acidified milk products. ⋯ Small or large doses of recombinant surfactant protein-C surfactant given 30 min after intratracheal acidified infant formula attenuated physiological, biochemical, and morphological lung damage.
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Anesthesia and analgesia · May 2004
The relationship between bispectral index and electroencephalographic parameters during isoflurane anesthesia.
Bispectral index (BIS) integrates various electroencephalographic (EEG) parameters into a single variable. However, the exact algorithm used to synthesize the parameters to BIS values is not known. The relationship between BIS and EEG parameters was evaluated during nitrous oxide/isoflurane anesthesia. Twenty patients scheduled for elective ophthalmic surgery were enrolled in the study. After EEG recording with a BIS monitor (A-1050) was begun, general anesthesia was induced and maintained with 0.5%-2% isoflurane and 66% nitrous oxide. Using software we developed, we continuously recorded BIS, spectral edge frequency 95% (SEF95), and EEG parameters such as relative beta ratio (BetaRatio), relative synchrony of fast and slow wave (SynchFastSlow), and burst suppression ratio. BetaRatio was linearly correlated with BIS (r = 0.90; P < 0.01; n = 253) at BIS more than 60. At a BIS range of 30 to 80, SynchFastSlow (r = 0.60; P < 0.01; n = 3314) and SEF95 (r = 0.75; P < 0.01; n = 3339) were linearly correlated with BIS. The correlation between BIS and SEF95 was significantly better than the correlation between BIS and SynchFastSlow (P < 0.01). At BIS less than 30, the burst suppression ratio was inversely linearly correlated with BIS (r = 0.76; P < 0.01; n = 65). At BIS less than 80, burst-compensated SEF95 was linearly correlated with BIS (r = 0.78; P < 0.01; n = 3404). In the range of BIS from 60 to 100, BIS can be calculated from BetaRatio. At surgical levels of anesthesia, BIS and SynchFastSlow (a parameter derived from bispectral analysis) or burst-compensated SEF95 (derived from power spectral analysis) are well correlated. However, our results show that SynchFastSlow has no advantage over SEF95 in calculation of BIS. ⋯ The relationship between bispectral index (BIS) and electroencephalographic parameters was evaluated during nitrous oxide/isoflurane anesthesia. At surgical levels of anesthesia, BIS and the relative synchrony of fast and slow wave (a parameter derived from bispectral analysis) or burst-compensated spectral edge frequency 95% (a parameter derived from power spectral analysis) are well correlated.