Anesthesia and analgesia
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Anesthesia and analgesia · Apr 1996
Norepinephrine does not potentiate porcine malignant hyperthermia.
Malignant hyperthermia (MH) is a rare genetic trait characterized by potential life-threatening episodes of hypermetabolism, hyperthermia, and muscle rigidity when susceptible humans or animals are exposed to triggering drugs. The role of norepinephrine (NE) in triggering MH is controversial. The purpose of this study was to show that NE does not initiate nor speed the onset of MH in susceptible swine exposed to known triggering drugs. ⋯ The large dose NE infusion resulted in increased total catecholamines throughout the study in the NE group with no effect on time to MH trigger compared to animals where mean arterial pressure (MAP) was maintained by IABP. Animals in all three groups with times to trigger of less than 30 min had significantly higher MAPs at control, 15 min, and trigger time than those with times to trigger of greater than 30 min. We conclude that NE does not trigger MH and that severe reduction of MAP delays the the onset of MH in susceptible swine.
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Anesthesia and analgesia · Apr 1996
Postoperative analgesia with continuous epidural sufentanil and bupivacaine: a prospective study in 614 patients.
To assess the efficacy and safety of postoperative analgesia with continuous epidural sufentanil and bupivacaine, we performed a prospective study in 614 patients undergoing major surgery. Before surgical incision, all patients received an initial dose of 50 micrograms sufentanil in 6-10 mL bupivacaine 0.125% via a lumbar or thoracic catheter. After 1 h, a continuous infusion was started with 50 micrograms sufentanil in 50 mL bupivacaine 0.125% at a rate of 6-10 mL/h. ⋯ Late respiratory depression was observed in three patients; in most patients only minor side effects were seen. Technical complications during epidural puncture or insertion of the catheter were 4% and 3%, respectively. We conclude that continuous epidural sufentanil and bupivacaine is safe and effective.
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Anesthesia and analgesia · Apr 1996
The effects of sevoflurane, isoflurane, halothane, and enflurane on hemodynamic responses during an inhaled induction of anesthesia via a mask in humans.
A rapid increase in isoflurane or desflurane concentration induces tachycardia and hypertension and increases-plasma catecholamine concentration. Little information is available as to whether sevoflurane, halothane, and enflurane induce similar responses during anesthesia induction via mask. Fifty ASA physical status I patients, aged 20-40 yr, and scheduled for elective minor surgery, received one of four volatile anesthetics: sevoflurane, isoflurane, halothane, or enflurane. ⋯ In contrast, changes in sevoflurane and halothane concentrations did not induce hyperdynamic responses. Plasma norepinephrine concentration in the isoflurane group was significantly higher than that in the sevoflurane group during 2.7 MAC (P = 0.022). We propose that there is a direct relationship between airway irritation of the anesthetic and immediate cardiovascular change during an inhaled induction of anesthesia.
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Anesthesia and analgesia · Apr 1996
Volume-controlled ventilation is made possible in infants by using compliant breathing circuits with large compression volume.
We studied the weight dependency of set tidal volume (VTset) during volume-controlled ventilation of 80 infants (ASA physical status I-IV, 0.7-20 kg), including prematures, neonates, and exprematures, who were anesthetized for major and minor surgery, including abdominal, thoracic, and neurosurgical procedures. After neuromuscular blockade and endotracheal intubation, infant's lungs were ventilated with an Ohmeda 7800 volume-limited ventilator and either a pediatric or adult circle breathing system (PC or AC) or a Bain circuit (Ba) and a pediatric- or adult-sized bellows (PB or AB). Except for larger and older infants in the ACAB group, body weight, age, peak inspiratory pressure (PIP), ETCO2, and SPO2 did not differ among groups. ⋯ We found that VTset/kg varied with weight in a curvilinear relationship where y represents volume added and x represents PIP (y = 175.02x-0.87; r2 - 0.87), whereby VTset is approximately 150-200 mL/kg for a 1-kg infant and approximately 25 mL/kg for infants > or = 10 kg. Ventilation was adequate in each infant, except for one with extremely poor pulmonary compliance. We conclude that large compression volumes associated with compliant breathing systems make possible the use of volume-controlled ventilators in small infants.
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Anesthesia and analgesia · Apr 1996
Environmental tobacco smoke: a risk factor for pediatric laryngospasm.
Adult patients who smoke are known to have airway complications during general anesthesia. The objective of this study was to explore the relationship between environmental tobacco smoke (ETS) exposure in the home and laryngospasm during general anesthesia in pediatric patients. A retrospective, cohort study was performed on pediatric ambulatory patients in the day surgery center and main operating room of a university hospital. ⋯ Of the 214 patients without domestic ETS exposure, 2 (0.9%) developed laryngospasm. The relative risk for developing laryngospasm was 10 times higher in the ETS-exposed patients compared with the non-ETS-exposed group (95% confidence interval = 2.2-45.6; P < 0.001). We conclude that ETS exposure is a strong risk factor for laryngospasm in infants and children during general anesthesia.