The influence of a bupivacaine and fentanyl epidural infusion after epidural fentanyl in patients allowed to ambulate in early labor.

UNLABELLED: Epidural fentanyl after a lidocaine and epinephrine test dose provides adequate analgesia and allows for ambulation during early labor. This study was designed to determine the influence of an epidural infusion of bupivacaine plus fentanyl administered after initiation of epidural labor analgesia with fentanyl. Specifically, we evaluated whether there is an increase in motor block or an increased time to request for further analgesic medication. Fifty-one laboring primigravid women at <5 cm cervical dilation who requested epidural analgesia were enrolled. After a 3-mL epidural test dose of 1.5% lidocaine with epinephrine (5 microg/mL), patients received fentanyl 100 microg via the epidural catheter. They then randomly received either an infusion (10 mL/h) of 0.0625% bupivacaine with fentanyl (3 microg/mL) or an infusion of preservative-free saline. After the administration of the initial analgesic, pain scores and side effects were recorded for each patient at 10, 20, and 30 min, every 30 min thereafter, and at the time of request for additional analgesic medication, by an observer blinded to the technique used. There were no demographic differences between the two groups. The mean duration of analgesia (time from initial dose to request for additional analgesia) was increased in the group that received a continuous infusion of bupivacaine and fentanyl compared with the Saline group (198 +/- 86 vs 145 +/- 50 min; P < 0.009). Side effects were similar between the two groups. No patient in either group experienced any detectable motor block. Fourteen patients chose to ambulate in the Saline group, and 12 patients chose to ambulate in the Infusion group. In early laboring patients, a continuous infusion of 0.0625% bupivacaine infusion with fentanyl (3 microg/mL) prolonged the duration until top-up was required, after epidural fentanyl 100 microg after a lidocaine and epinephrine test dose, and did not cause any clinically detectable motor block. IMPLICATIONS: A 0.0625% bupivacaine and fentanyl (3 microg/mL) infusion, when added to epidural fentanyl (100 microg), prolongs the analgesic duration without increasing motor block in women in early labor.

Living related liver transplantation in infants and children: report of anesthetic care and early postoperative morbidity and mortality.

STUDY OBJECTIVE: To determine those infants at high risk for perioperative complications and mortality following living, related liver transplantation. DESIGN: Retrospective chart review. SETTING: Large metropolitan teaching hospital. MEASUREMENTS AND MAIN RESULTS: The charts and anesthetic records of the 12 infants and children who received the left lateral hepatic segment from a living relative the past 2 years at our institution were reviewed. The records were examined to determine the causes of perioperative morbidity and to identify patients at high risk for serious complications and mortality. All infants and children (mean +/- SD age, 29+/-30 months; weight, 13.6 +/-6.8 kg) survived the operation (8.3+/-1.7 hours) without intraoperative complications. The average blood loss, including 500 mL of recipient blood used to flush the liver before reperfusion, was 1483 +/-873 mL (119+/-70 mL/kg). Three infants developed portal vein thrombosis, and one of these infants also had hepatic artery thrombosis. The risk of vessel thrombosis was significantly higher (3/3 vs. 0/9; p<0.0045) in infants less than 9 kg body weight, as was the risk of death (2/3 vs. 0/9; p<0.045). Both children who died had vascular thrombosis. Other serious complications were bleeding, 6; infection, 7; acute rejection, 3; and bile leak, 2. CONCLUSIONS: Infants and children can successfully undergo living, related liver transplantation. However, the risks of vascular complications and death are greater in infants less than 9 kg body weight.

Living liver donor surgery: report of initial anesthesia experience.

The charts and anesthetic records of 12 patients who donated the left lateral segment of their liver to a related infant or child to treat liver failure were retrospectively reviewed. Blood loss, need for transfusion, fluids administered, surgical length, and perioperative complications were investigated. The records also were examined to determine the hemodynamic stability of patients undergoing donor hepatectomy to assess their need for invasive monitoring. There were no episodes of hypotension or hemodynamic instability. The average operating time was 9.6 +/- 1.1 hours. The blood loss was 562 +/- 244 mL (range 300 to 1100 mL). Four patients received their own cell saver blood (200 mL, 220 mL, 300 mL, 475 mL), and one patient received 1 U (350 mL) of predonated autologous blood. The average hemoglobin decreased significantly (p = 0.001) from a preoperative value of 14.1 +/- 1.2 to 12.3 +/- 1.8 g/dL in the recovery room. All patients were extubated in the operating room or recovery room. Patients were discharged home in 6.9 +/- 1.3 days (range 5 to 9 days). Living-related liver resection can be performed with noninvasive monitoring and without the need for heterologous blood products.

Hemodynamic and metabolic manifestations of acute endotoxin infusion in pigs with and without the malignant hyperthermia mutation.

BACKGROUND: The hypermetabolic state induced by acute endotoxemia and malignant hyperthermia (MH) may be indistinguishable. The aims of this study were (1) to investigate the differences between MH and sepsis, (2) to determine whether acute endotoxemia can trigger MH, and (3) to establish the effects of dantrolene in these two disorders. METHODS: Three groups of swine were studied. All pigs were invasively monitored and initially anesthetized with nontriggering agents. A placebo MH-susceptible group (n = 5) received normal saline whereas the endotoxin groups (MH-susceptible, n = 6; MH-negative, n = 4) received intravenous endotoxin (250 microg/kg total) during 2.5 h. Halothane (1.5%) and succinylcholine (2-4 mg/kg) were then administered, followed by two doses of dantrolene (4 mg/kg total). RESULTS: Endotoxin infusion resulted in pulmonary hypertension and systemic hypotension in pigs with and without the MH mutation, but did not trigger MH. Halothane and succinylcholine triggered MH, evidenced by a markedly higher oxygen consumption in the MH-susceptible pigs that received endotoxin (325+/-196 ml/min) and those that did not (374+/-110 ml/min) compared to the MH-negative pigs (69+/-15 ml/min, P<0.0009), as well as muscular rigidity in the susceptible animals. Dantrolene reversed these changes. Three of the six MH-susceptible pigs that received endotoxin died; two died soon after triggering and one after dantrolene administration. In contrast, none of the MH-negative pigs or the MH-susceptible pigs that did not receive endotoxin died (0 of 9 vs. 3 of 6, P = 0.044). CONCLUSION: Endotoxemia does not trigger MH, but may worsen outcome if it occurs.

Differential diagnosis of thyroid crisis and malignant hyperthermia in an anesthetized porcine model.

The intra-operative differential diagnosis between thyroid crisis and malignant hyperthermia can be difficult. Also stress alone can trigger MH. The purposes of this study were: 1) to investigate the metabolic and hemodynamic differences between thyroid crisis and MH, 2) determine how thyroid crisis affects the development of MH, and 3) determine if the stress of thyroid crisis can trigger MH in susceptible individuals. We studied MH susceptible and normal swine. Two groups of animals (MH susceptible and normal) were induced into thyroid crisis (critical core hyperthermia, sustained tachycardia and increase in oxygen consumption) by pretreatment with intraperitoneal triiodothyronine (T3) followed by large hourly intravenous injections of T3. Two similar groups were given intravenous T3 but no pretreatment. These animals did not develop thyroid crisis and served as controls. Thyroid crisis did not result in metabolic changes or rigidity characteristic of an acute episode of MH. When the animals were subsequently challenged with MH triggering agents (halothane plus succinylcholine) dramatic manifestations of fulminant MH episodes (acute serious elevation in exhaled carbon dioxide, arterial CO2, rigidity and acidemia) were noted only in the MH susceptible animals. Although thyroid crisis did not trigger MH in the susceptible animals it did decrease the time to trigger MH (14.1 +/- 7.2 minutes versus 47.2 +/- 17.7 minutes, p < 0.01) in susceptible animals. Hormone induced elevations in temperature and possibly other unidentified factors during thyroid crisis may facilitate the triggering of MH following halothane and succinylcholine challenge.

Is dantrolene safe to administer in sepsis? The effect of dantrolene after endotoxin administration in dogs and rats.

Hyperthermia from septic shock may be indistinguishable from malignant hyperthermia. Dantrolene may be given in septicemia if the diagnosis is unclear. To determine if dantrolene is safe to use in sepsis, two studies were performed. In study 1, 18 anesthetized dogs in which profound septic shock was induced with 5 mg/kg of intravenous Escherichia coli endotoxin were randomized to receive (30 min later) intravenous injections of 10 mg/kg of dantrolene solution, the diluent of dantrolene, or maintenance intravenous fluids alone. The use of dantrolene solution and the diluent of dantrolene resulted in similar but transient statistically significant increases in the cardiac filling pressures and cardiac outputs and decreases in the vascular resistances compared with the control dogs. In a second study, 185 rats were randomized into five equal groups. Groups 1, 2, and 3 received 15 mg/kg of intraperitoneal Escherichia coli endotoxin followed 30 min later by 10 mg/kg of dantrolene solution, the diluent of dantrolene, or normal saline. Groups 4 and 5 received normal saline followed by dantrolene or normal saline. The survival of groups 1, 2, and 3 was less at 24 h (P less than 0.0001) than that of either control group, but was not significantly different from one another. The results suggest dantrolene can be administered safely under clinical conditions where the cause of hyperthermia and shock cannot clearly be ascribed to malignant hyperthermia or septicemia.