A study of the dosage and duration for levobupivacaine infusion by the caudal-epidural route in infants aged 3-6 months.

BACKGROUND: The local anesthetic, levobupivacaine, is the safer enantiomer of racemic bupivacaine. Present protocols for levobupivacaine are based on studies and pharmacokinetic modeling with racemic bupivacaine. AIMS: The aim is to investigate total serum levobupivacaine concentrations after a caudalepidural loading dose followed by a maintenance infusion over 48 hours in infants aged 3-6 months. METHODS: The clinical trial was conducted in eight infants aged 3-6 months, undergoing bladder exstrophy repair. Pharmacokinetic modeling allowed optimization of clinical sampling to measure total levobupivacaine and α1 -acid glycoprotein and prediction of the effect of α1 -acid glycoprotein on levobupivacaine plasma protein binding. RESULTS: The observed median total levobupivacaine serum concentration was 0.30 mg/L (range: 0.20-0.70 mg/L) at 1 hour after the loading dose of 2 mg/kg. The median total levobupivacaine concentration after 47 hours of infusion, at 0.2 mg/kg/h, was 1.21 mg/L (0.07-1.85 mg/L). Concentrations of α1 -acid glycoprotein were found to rise throughout the study period. Pharmacokinetic modeling suggested that unbound levobupivacaine quickly reached steady state at a concentration of approximately 0.03 mg/L. CONCLUSION: The study allows the development of a pharmacokinetic model, combining levobupivacaine and α1 -acid glycoprotein data. Modeling indicates that unbound levobupivacaine quickly reaches steady state once the infusion is started. Simulations suggest that it may be possible to continue the infusion beyond 48 hours.

Perioperative complications and outcomes in children with cerebral palsy undergoing scoliosis surgery.

INTRODUCTION: Neuromuscular scoliosis is a known risk factor for postoperative complications after corrective spine surgery. Few studies have looked at the preoperative factors affecting postoperative complications in children with cerebral palsy. AIM: The aim of this study was to examine the factors that might influence postoperative course in patients with cerebral palsy undergoing spine surgery for scoliosis. METHODS: Nineteen case notes of children with cerebral palsy who had spine surgery (2008-2014) were reviewed retrospectively. Preoperative comorbidities and postoperative complications were noted and complications were classified as major and minor. RESULTS: Thirteen out of 19 (68.4%) patients had two or more systemic comorbidities. Most common comorbidities included reflux and seizure disorder. Nine patients (49%) had at least one major complication. About 5/19 patients had respiratory complications requiring ventilation and 4/19 had massive blood loss. A higher incidence of postoperative major complication was recorded in the group with two systemic comorbidities as compared to those with less than two systemic comorbidities (47% vs 16%). Both patients who had a single-stage anterior release and posterior fixation had a major complication. CONCLUSION: Presence of two or more comorbidities and thoracotomy are risk factors for perioperative complications in children with cerebral palsy undergoing surgery for scoliosis correction.

The pattern of blood loss in adolescent idiopathic scoliosis.

BACKGROUND CONTEXT: Previous studies have shown that modern intraoperative blood-saving techniques dramatically reduce the allogeneic transfusion requirements in surgery for adolescent idiopathic scoliosis (AIS). No studies have looked at the pattern of postoperative hemoglobin (Hb) in AIS patients undergoing corrective spinal surgery and correlated this with the timing of allogeneic transfusion. PURPOSE: To describe the pattern of perioperative blood loss in instrumented surgery for AIS. We look at the recommendations regarding an ideal preoperative Hb, the need for preoperative cross-matching, and the timing of postoperative Hb analysis. STUDY DESIGN: This was a retrospective case series. Surgeries were performed by one of four substantive pediatric spinal surgeons within a single regional center over a 3-year period. PATIENT SAMPLE: A consecutive series of 86 patients who underwent posterior instrumented fusion for AIS were included: 10 males and 76 females. Mean age was 14 years (range 10-17 years). All patients had posterior instrumented fusion using various blood-saving techniques (eg, cell-saver). All patients were cross-matched preoperatively, and our transfusion trigger value (TTV) was 7 g/dL. OUTCOME MEASURES: Hemoglobin level was the outcome measure. Hemoglobin readings were obtained preoperatively, within 2 hours of surgery, and daily up to 5 days after surgery. This physiologic measure was assessed using routine blood sampling techniques and standardized laboratory processing. METHODS: Patient predictor variables (demographic and surgical) were assessed for association with Hb levels in a hierarchical model, with repeated Hb readings at the lower level being clustered within an individual patient at the upper level of the structure. The variation of Hb levels within individuals was compared with mean levels in different individuals via the variance partition coefficient of the model structure. RESULTS: No patients required intraoperative allogeneic transfusion. Only four patients (4.65%) received allogeneic transfusion, all within 2 days of surgery. A clinically important drop in Hb occurred within the first 2 postoperative days, rising thereafter. The average postoperative drop in Hb was 4.1 g/dL. Young males had lower postoperative Hb values. Neither the preoperative curve magnitude (Cobb angle of major curve) nor the number of vertebrae/levels fused significantly affected the blood loss. CONCLUSIONS: We recommend setting a minimum preoperative Hb value that is 5 g/dL higher than your TTV. Because no patients required an intraoperative transfusion when using modern blood-saving techniques, preoperative cross-matching is unnecessary and potentially wasteful of blood reserves. Hemoglobin analysis beyond the second postoperative day is unnecessary unless clinically indicated.

Perioperative anxiety and postoperative behavioural disturbances in children undergoing intravenous or inhalation induction of anaesthesia.

BACKGROUND: There are few published data comparing the psychological effects of intravenous (i.v.) and inhalation methods of anaesthesia induction in children. In the present study, we compared perioperative anxiety and postoperative behavioural changes in children undergoing standardized i.v. induction with thiopental and inhalation induction with sevoflurane for routine ear, nose and throat surgery. METHODS: Children were randomly assigned to receive inhalation induction with sevoflurane or i.v. induction with thiopental. Anxiety was assessed on arrival, at induction and 30 min after transfer to the recovery room using a four-point scale. The incidence of postoperative behavioural disturbances was determined using a postoperative questionnaire. RESULTS: Significantly more children were anxious during induction in the i.v. group than in the inhalation group [23 of 50 (46%) versus 5 of 50 (10%); P = 0.0001]. Mean induction time was shorter (5.6 versus 7.0 min; P = 0.0001) and recovery time longer (30.5 versus 10.4 min; P = 0.0001) in the i.v. group compared with the inhalation group. Problematic behavioural changes were reported in the first 2 weeks after surgery in nine of 32 children (28%) in the i.v. group and 16 of 34 (48%) children in the inhalation group (P = 0.13). CONCLUSIONS: Although children were more anxious during i.v. induction than inhalation induction, there was no difference in the incidence of behavioural disturbances in the first 2 weeks postoperatively.