Anesthesia and analgesia
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Anesthesia and analgesia · Oct 2001
Clinical TrialThe optimal length of insertion of central venous catheters for pediatric patients.
Incorrect positioning of central venous catheters (CVC) in infants and children may lead to serious complications such as perforation of the heart or great vessels. CVC position is not usually assessed until the first postoperative chest radiograph, potentially leaving malposition undetected for several hours. We studied a series of 452 right internal jugular and subclavian catheter placements in infants and children undergoing surgery for congenital heart disease, and measured the distance from the skin insertion site to the radiographic junction of the superior vena cava and right atrium (RA). Based on these data, the following formulae predict that a CVC will be positioned above the RA 97% of the time: correct length of insertion (cm) = (height in cm/10) - 1 for patients < or =100 cm in height, and (height in cm/10) - 2 for patients >100 cm in height. Weight-based recommendations were also developed which predict placement of CVC above the RA 98% of the time. ⋯ This study assessed central venous catheter placement in 452 infants and children undergoing cardiac surgery. Simple, clinically useful guidelines based on height and weight were developed to prevent malposition of these catheters, which may cause serious complications such as perforation of the heart or great vessels.
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Anesthesia and analgesia · Oct 2001
The anesthetic management of triplet cesarean delivery: a retrospective case series of maternal outcomes.
Spinal anesthesia for the cesarean delivery of triplets is associated with an increased incidence of maternal hypotension and placental hypoperfusion. We performed a retrospective case series analysis between January 1992 and June 2000 to evaluate the effects of regional anesthetic techniques for cesarean delivery in triplet pregnancies on maternal and neonatal outcome. Spinal and epidural anesthesia were compared with respect to intraoperative hemodynamics and neonatal outcomes. Ninety-six triplet pregnancies were delivered by cesarean section, of which 91 received regional anesthesia. A statistically significant decrease in systolic blood pressure was demonstrated immediately after the induction of spinal as compared with epidural anesthesia. The total volume of IV crystalloid used was significantly larger in the Spinal Anesthesia group. The number of patients receiving more than 15 mg of ephedrine and the cumulative dose of ephedrine was significantly larger in the Spinal group compared with the Epidural group. There were no differences in the rate of perioperative complications between the Spinal and Epidural Anesthesia groups. Neonatal Apgar scores were similar in both groups. The data suggest that both epidural and spinal anesthesia for triplet cesarean delivery are safe techniques, but the latter is associated with a larger initial decrease in systolic blood pressure. This decreasing of systolic blood pressure, however, remained within the physiological range and did not seem to be clinically significant. The need for more crystalloid fluids and ephedrine should be anticipated when spinal anesthesia is used for these cases. ⋯ A large retrospective case series of the effects of spinal and epidural anesthesia on maternal hemodynamic profile during cesarean delivery for triplet gestation was performed. Our findings suggest that spinal anesthesia results in outcomes comparable to epidural anesthesia for both mother and newborns.
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Anesthesia and analgesia · Oct 2001
Clinical TrialThe pharmacokinetics of epidural ropivacaine in infants and young children.
The pharmacokinetic variables of ropivacaine were characterized after epidural bolus injection in pediatric patients. The subjects, 7 infants (aged 3-11 mo) and 11 young children (aged 12-48 mo), received 1.7 mg/kg of ropivacaine via a lumbar epidural catheter. Total plasma concentrations of ropivacaine measured over 24 h were assayed by high-pressure liquid chromatography, and pharmacokinetic modeling was performed by Nonlinear Mixed Effects Modeling analysis. The median peak venous plasma concentrations (C(max)) in infants and young children were 610 microg/L (interquartile range [IQR], 550-725 microg/L) and 640 microg/L (IQR, 540-750 microg/L), respectively. The median times to maximum plasma ropivacaine concentration (T(max)) were 60 min (IQR, 60-120 min) in infants and 60 min (IQR, 30-90 min) in young children. There were no statistical differences between median values of C(max) and T(max) between infants and young children. The calculated clearance (CL) in infants was 4.26 mL x min(-1) x kg(-1) (9% coefficient of variation), and in young children it was 6.15 mL x min(-1) x kg(-1) (11% coefficient of variation). The CL for infants was significantly less than the CL for young children (P < 0.01). The volume of distribution was estimated to be 2370 mL/kg (9% coefficient of variation) for both young children and infants. No systemic toxicity was observed in either group. ⋯ This study revealed that the pharmacokinetic variables of lumbar epidural bolus ropivacaine in pediatric patients aged 3 to 48 mo are similar to those of adults, except that drug clearance was less in infants compared with older children.
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Anesthesia and analgesia · Oct 2001
Case ReportsThe inability to detect expired carbon dioxide after endotracheal intubation as a result of one-way valve obstruction of the endotracheal tube.
Failure to tracheally intubate and ventilate the lungs is a major cause of anesthesia morbidity. Expired carbon dioxide monitoring has become a standard for assessing correct endotracheal tube placement. We present a case of failure to detect expired carbon dioxide after successful intubation resulting from a one-way valve obstruction of the endotracheal tube.
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Anesthesia and analgesia · Oct 2001
Epidural labor analgesia and neonatal sepsis evaluation rate: a quality improvement study.
Labor epidural analgesia (LEA) is allegedly associated with maternal fever and an increase in the newborn sepsis work-up (SWU) rate. In this study, we evaluated whether LEA causes an increase in the SWU rate compared with a Control group given parenteral narcotics for labor pain. Maternal and neonatal data were collected prospectively for a continuous quality improvement database. Odds ratios were calculated by using multiple logistic regression for various triggers for SWU in the neonate. Of the 1177 primiparous women and their neonates studied, 922 women received LEA and 255 women received parenteral analgesics. A small but statistically significant increase in maternal and neonatal temperatures occurred in parturients receiving LEA. The SWU rates were 7.5% in the LEA group and 9.4% in the Controls (not significant). Triggers identified for SWU were birth weight (odds ratio = 116, P = 0.000), gestational age (odds ratio = 86.6, P = 0.000), meconium aspiration and respiratory distress requiring intubation (odds ratio = 8.6, P = 0.000), hypothermia at birth (odds ratio = 7.1, P = 0.001), maternal Group B beta-hemolytic streptococcal colonization (odds ratio = 6, P = 0.000), and preeclampsia or hypertension (odds ratio = 3.5, P = 0.03). There was no association between LEA and SWU. ⋯ Although it has been suggested that epidural analgesia for labor contributes to an increase in neonatal sepsis work-up (SWU), this retrospective analysis shows that epidural analgesia is not associated with an increase in SWU. The factors that were found to contribute to SWU included low birth weight, low gestational age, meconium aspiration or respiratory distress at birth, hypothermia at birth, maternal group B beta-hemolytic colonization, and preeclampsia or hypertension.