Cerebrospinal fluid volume in neonates undergoing spinal anaesthesia: a descriptive magnetic resonance imaging study.

BACKGROUND: Spinal anaesthesia (SA) reduces the risk of postoperative apnoea after general anaesthesia in neonates. In 30% of patients, however, the duration of anaesthesia provided does not allow completion of surgery. When compared with term infants, formerly preterm neonates experience a shorter duration of anaesthesia after SA. A difference in the cerebrospinal fluid (CSF) volume between those two populations could explain this difference, but this has never been investigated. The study was designed to evaluate the relationship between the spinal CSF volume and patient characteristics in neonates. METHODS: Sixty-seven neonates, aged 30-60 weeks postconception, were included in this study. Their spinal CSF volumes were calculated using magnetic resonance imaging, and these volumes were plotted individually against sex, term at birth, birth weight, current gestational age, civil age, and weight. Correlations between CSF volume and these variables were investigated. RESULTS: Fifty-four neonates completed the study. The CSF volume was found to be closely and linearly correlated with weight and postconceptional age. The relationship between spinal CSF volume and weight can be described as follows: CSF volume (ml)=1.94 weight (kg)+0.13. The CSF volume was not correlated with sex, weight, or term at birth, nor with civil age. CONCLUSIONS: The amount of spinal CSF in neonates can be estimated as 2 ml kg(-1) in both term and formerly preterm neonates. A difference in the CSF volume between them does not provide an explanation for a shorter duration of SA in the latter. Our findings reinforce weight-adjusted dosage of SA in neonates.

Population pharmacokinetics of nalbuphine after surgery in children.

BACKGROUND: Nalbuphine is an opioid analgesic agent widely used for control of mild-to-severe pain. However, limited data are available on the pharmacokinetics of this drug in children. The aim of this study was to characterize the population pharmacokinetics of nalbuphine in patients with ages ranging from 1 to 11 yr and to identify patient characteristics partially explaining inter-individual variability in nalbuphine pharmacokinetic parameters. METHODS: Twenty-two children were included in this study. They received nalbuphine after surgery by continuous infusion (loading dose, 0.2 mg kg(-1) over 10 min followed by continuous infusion of 0.8 mg kg(-1) over 24 h). If pain relief was not adequate, 0.1 mg kg(-1) bolus doses were allowed in 10 min. Eleven blood samples were collected per patient. The data were analysed by non-linear mixed-effect modelling with the use of a two-compartment structural model. RESULTS: Twenty patients completed the study. In the final model, the parameter values were standardized for a body weight of 70 kg using an allometric model. Population parameter estimates were: clearance 130 litre h(-1) 70 kg(-1), inter-compartment clearance 75.6 litre h(-1) 70 kg(-1), central volume of distribution 210 litre 70 kg(-1), and peripheral volume of distribution 151 litre 70 kg(-1). In the children of this study, total clearance expressed in litre h(-1) kg(-1) decreased significantly with increasing age and the elimination half-life significantly increased. CONCLUSIONS: The allometric power model developed in this study best reflected the data and may be useful for dose adjustment.

[Comparison of saline, air, and a mixture oxygen-nitrous oxide for endotracheal cuff tracheal tube inflation in children? A prospective randomized trial]. / Comparaison de sérum salé, d'air et d'un mélange oxygène-protoxyde d'azote pour le remplissage des ballonnets de sondes d'intubation chez l'enfant? Étude prospective randomisée.

OBJECTIVE: The purpose of the present study was to compare how many inflate and deflate are necessary to maintain the endotracheal tube cuff pressure between 15 and 35 cm H2O by using air, O2-N2O mix or saline solution. STUDY DESIGN: Randomized and prospective study. PATIENTS AND METHODS: Ninety children from 1 month to 15 years of age were included in the study. All patients were ventilated with O250%-N2O50%. Subsequently, the patients were divided in three groups: (1) Group 1: patients with air inflated cuffs; (2) Group 2: patients with O2-N2O mix inflated cuffs; (3) Group 3: patients with saline solution inflated cuffs. In all groups cuffs were inflated to reach an intracuff pressure of 20 cm H2O. The cuff pressure was then monitored every 10 minutes and adjusted to be between 15 and 35 cm H2O. Laryngeal and tracheal symptoms were noted in the recovery room. RESULTS: The three groups of patients were similar for age, weight, and sex. The length of surgery was significantly longer in Group 3. The deflate rate was higher in Group 1 (60%) than in Group 2 (10%) or 3 (3.3%) (p<0.0001). The inflate rate was higher in Group 2 (76.6%) than in Group 1 or 3 (both 3.3%) (p<0.0001). Side effects were comparable in the three groups of patients. CONCLUSION: Using air or O2-N2O mix to inflate cuffs is not reliable. SSI helps to maintain a more stable cuff pressure but monitoring is difficult and sometimes contraindicated by tracheal tubes producers. Inflating cuffs with air and regularly monitoring pressure is the most reliable and easiest technique.

[Continuous epidural block versus continuous psoas compartment block for postoperative analgesia after major hip or femoral surgery in children: a prospective comparative randomized study]. / Analgésie péridurale continue versus bloc continu du compartiment psoas pour l'analgésie postopératoire après chirurgie majeure du bassin ou du fémur chez l'enfant : étude prospective comparative randomisée.

BACKGROUND: Intravenous opioids and/or continuous epidural block (CEB) are used for postoperative analgesia after hip and/or femoral shaft surgery but adverse effects limit their use in children. A continuous psoas compartment block (CPCB), effective technique in adults can be an alternative. In this randomized comparative study, we wanted to evaluate CEB and CPCB in children after major hip surgery in terms of adverse events, pain relief and ropivacaine plasma concentrations. METHODS: After ethical committee and parents' approval, 40 children scheduled for hip surgery were included and randomly allocated to receive CPCB or CEB. After general anaesthesia induction, 0.5 mL/kg of 0.375% ropivacaine were injected via the epidural or lumbar plexus catheter. After surgery, 0.1 ml/kg per hour (group CPCB) or 0.2 ml/kg per hour (group CEB) of 0.2% ropivacaine was infused for 48h. Post-operative pain was evaluated using VAS or CHIPPS scores values at h1, h6, h12, h18, h24, h36 and h48, as well as doses of first line (paracetamol 15 mg/kg/6h) or second line rescue analgesia (0.2mg/kg intravenous nalbuphine), if pain score remained high after 30 mm. niflumic acid was systematically used. Adverse events were noted as well as parents' satisfaction at 48h. Ropivacaine plasma concentrations were measured four times up to 48h (h1, h6, h24 and h48) by high performance gas chromatography. RESULTS: Forty children 1 to 12 years old (CPCB=20, CEB=20) were included. The demographic data were equivalent in both groups. Postoperative analgesia was excellent for both continuous block techniques during the whole studied period. Doses of rescue analgesics were comparable in both groups at the end of the 48h. Number of children who had at least one side effect is significantly higher in CEB group. Furthermore, the number of local anaesthetic premature stops was significantly more frequent in this group. Median values of ropivacaine plasma level in CEB group were significantly higher than CPCB group at h6 and h24. Ten parents in the CEB group and 15 in CPCB group were satisfied. CONCLUSION: Continuous psoas compartment block is an effective technique of postoperative analgesia after major hip or femoral surgery in children. It equally manages postoperative pain with significantly less adverse event and decreased ropivacaine doses and plasma concentration than CEB.

Population pharmacokinetics of the two enantiomers of tramadol and O-demethyl tramadol after surgery in children.

BACKGROUND: Few data are available on the stereoselective pharmacokinetics of tramadol in children. The aim of this study was to develop a population pharmacokinetic model for the (+)- and (-)-enantiomers of tramadol and its O-demethyl tramadol metabolite (M1) in children. METHODS: Twenty-five children (1-8 yr) were included in this study. Tramadol was administered after surgery by continuous infusion (loading dose, 2 mg kg(-1) i.v. over 10 min followed by continuous infusion of 8 mg kg(-1) over 24 h). If pain relief was inadequate, additional 1 mg kg(-1) i.v. bolus doses of tramadol were given over 10 min. A two-compartment structural model was used with NONMEM. RESULTS: For both enantiomers of tramadol, weight was the only patient characteristic parameter showing significant covariate effects on clearance (CL). CL increased by 5.7-6.1 litre h(-1) between 8-12 and 13-16 kg, and by 2.4-3.3 litre h(-1) between 13-16 and 17-33 kg. The rate constants associated with the metabolite elimination [0.144 h(-1), (+)-M1 and 0.18 h(-1), (-)-M1] were smaller than the elimination rate constants of the parent drugs [0.243 h(-1), (+)-tramadol and 0.241 h(-1), (-)-tramadol], suggesting that the metabolite disposition was rate-limited by its elimination. The presence of two subpopulations of patients was suspected on the basis of the observed bimodal distributions of the AUC(M1)/AUC(tramadol) ratios. CONCLUSIONS: The results of this study combine relationships between tramadol CL and patient covariates that may be useful for dose adjustment. Polymorphism is likely to contribute to the interpatient variability observed in the AUC M1/AUC tramadol ratios.

[A comparative study of the feasibility and limits of ambulatory surgery in infants under and over one year of age]. / Etude comparative de la faisabilité et des limites de la chirurgie ambulatoire chez le nourrisson et chez l'enfant de plus d'un an.

OBJECTIVE: Outpatient surgery in pediatrics is attractive for several reasons. Although 6-8 months has been generally acknowledged as the lower age limit, no minimal age has been clearly established. This study evaluated the outcomes and limits of outpatient surgery in infants from 4 months to 1 year of age. MATERIAL AND METHODS: Between 1996 and 2003, 935 patients were admitted to our hospital for outpatient surgery; of these, 152 were between 4 months and 1 year (mean: 6 months). The indications were essentially surgery to the external genitalia and surgery to remove hernias. The following were exclusion criteria: age below 4 months, ASA scores equal to or above 3, and premature birth with either respiratory distress syndrome or a near-miss of sudden death. RESULTS: More than 98% of the infants met the criteria for outpatient surgery. Cancellations (1.97 vs. 0.51%, P > 0.05), conversions to classic hospitalization (0.65 vs. 0.37%, P > 0.05), postoperative complications (0.65 vs. 0.25%, P > 0.05), rehospitalization (0.65 vs.0.25%, P > 0.05) and relapse of the initial pathology (0.65 vs. 0.63%, P > 0.05) were not more frequent in these infants than in infants over 1 year. CONCLUSION: Pediatric outpatient surgery can be proposed from the age of 4 months without increasing the postoperative risk, either anesthetic or surgical, included for selected former premature infants.

Continuous psoas compartment blocks after major orthopedic surgery in children: a prospective computed tomographic scan and clinical studies.

UNLABELLED: Femoral shaft or hip surgeries are very painful for children. We conducted both computed tomographic (CT) and clinical prospective studies to define new landmarks in children and to evaluate the effectiveness of continuous psoas compartment blocks (CPCBs) using disposable elastomeric pumps. In a preliminary CT scan study of 20 patients, the plexus depth was correlated to patient age and the optimal point of puncture for CPCB was three-quarters of the distance from the spinous process of L4 to a line parallel to the spinal column passing through the posterior superior iliac spine. In a subsequent prospective series, a CPCB was administered before surgery to 15 children for pain relief after femoral and hip osteotomies. After general anesthesia, a 0.5 mL/kg bolus of a mixture of 1% lidocaine with epinephrine (1/200.000) and 0.5% ropivacaine was injected through the CPCB catheter. After contrast media assessment of the catheter location, a disposable pump (Infusor LV); Baxter, Paris, France) with 0.2% ropivacaine was connected and pump flow was adjusted to the patient's weight (0.2 mg x kg(-1) x h(-1)). Postoperative pain was evaluated using a visual analog scale or the Children and Infants Postoperative Pain Score at hour H1, H6, H12, H18, H24, H36, and H48, and in terms of rescue analgesia, adverse events, and motor blocks. All blocks were effective during surgery. Postoperative analgesia was excellent. The median pain scores were 1 for H1 and 0 beginning H6. The motor blockade was minimal before 24 h and absent thereafter. No major adverse event was noted. Parents of 93% of the children were satisfied. We conclude that postoperative analgesia with CPCB is a very effective technique in children after major proximal lower limb orthopedic surgery. The CT scan landmarks described in this study were more medial than the conventional landmarks used in the literature. IMPLICATIONS: Continuous psoas compartment blocks provide optimal pain relief in children after major orthopedic surgery without major adverse events. The landmarks used, defined in a preliminary computed tomographic scan study, were more medial than conventional landmarks.

Preoperative screening for von Willebrand disease type 1: low yield and limited ability to predict bleeding.

Type 1 von Willebrand disease (vWd) is the most common hereditary bleeding disorder. The objective of this study was to measure the von Willebrand factor antigen (vWf:Ag) in a large cohort of patients who underwent surgery to assess the role of a new rapid immunoassay in a screening procedure for vWd in preoperative conditions. We studied 832 consecutive patients (540 children, 292 adults) referred to the surgical departments. For each patient we determined the vWf:Ag level with two different assays, an enzyme-linked immunosorbent assay (ELISA)(Asserachrom vWf:Ag; Diagnostica Stago, France) and a rapid immunoassay (Liatest vWf:Ag; Diagnostica Stago). Using the reference test, we found 30 of 832 patients with a vWf:Ag value below the lower limits (21 U/dL to 46 U/dL). The coefficient of correlation between the two tests was 0.77 (P = .001). When receiver operating characteristic curves were used, the cutoff value calculated to detect vWf:Ag defect with the rapid assay was 68.5 U/dL, leading to 0.36% false negatives and 9.7% false positives. Thus the rapid immunoassay appears to be a useful and easy method that is adaptable to urgent situations. Among the 30 patients with low values in ELISA, 8 had personal or familial bleeding history. Repeat blood samples confirmed the diagnosis of vWd in 5 cases, leading to a prevalence of vWd type 1 of 0.6%. However, in our series the absence of severe bleeding complications raises the question of the screening and the management of patients bearing a type 1 Willebrand disease during surgery.

[Anaphylactic shock after a test-dose of aprotinin in pediatric orthopedic surgery]. / Choc anaphylactique après dose-test d'aprotinine en chirurgie orthopédique pédiatrique.

A case of severe anaphylactic shock in a 28-month-old child following a testing-dose of aprotinin during major orthopaedic surgery is reported. Two months earlier, aprotinin had been administered during a similar controlateral surgical procedure. The grade III anaphylactic accident required a 48 h treatment in an intensive care unit. The outcome was favourable. The pin-prick tests were positive for aprotinin, substantiating the diagnosis of anaphylactic shock, whereas the test with specific IgE was negative. The value of current diagnostic tools for aprotinin allergy is discussed. The administration of a testing-dose in a patient previously treated with aprotinin cannot be recommended. Considering the risk for allergy, aprotinin should only be administered for recognized indications such as major orthopaedic surgery. Before any readministration of this agent an assessment by an allergist-anaesthetist is essential for determination of the risk-benefit ratio.

[Local analgesic action by direct effect of pethidine on the nervous trunks]. / Action analgésique locale par effet direct sur les troncs nerveux de la péthidine.

The aim of this paper is to study the analgesic effects of meperidine (pethidine) on nervous trunks. First we compared the analgesic effect of pethidine in surgery of knee and femur. Meperidine was randomly administered either by femoral block or intravenously. The onset of analgesia was shorter with femoral block (5 minutes against 146 minutes). In the surgery of shoulder, nerve block with meperidine was performed using intersclalenic block. Plasma concentrations ar lower (maximum of 0.29 mg per liter) than intravenous therapeutic concentrations (between 0.5 and 0.7 mg per liter). So we can conclude as do other papers, there is a direct effect of meperidine on nervous trunks. This effect is probably mediated by receptors located on nervous trunks.

Tolerance of intraperitoneal chemohyperthermia with mitomycin C: in vivo study in dogs.

Tolerance of intraperitoneal chemohyperthermia (IPCH) with mitomycin C (2 mg/kg) by irrigation of the peritoneal cavity via a closed circuit system was evaluated in Beagle dogs for possible use in the management of human peritoneal carcinomatosis. Of dogs, 24 underwent three digestive anastomoses each. They were randomized into three groups: control (n = 6), intraperitoneal hyperthermia (n = 8) and IPCH (n = 10). Peritoneal temperatures were maintained between 41-43 degrees C for 60 min. Tolerance was evaluated through clinical follow-up, biological samples (serum electrolytes, blood counts and serum enzymes), histological examinations and post-mortem macro- and microscopic controls of anastomosis. Mortality and morbidity rates were not different in the three groups. No anastomotic leakage occurred. Evidence of biological toxicity was minimal. Histological examinations showed no definitive tissue damage. IPCH appears to be a safe and reliable device in dogs. Plans to combine IPCH with MMC in surgical resection of patients with peritoneal carcinomatosis are underway.

Bromocriptine inhibition of hyperprolactinemia during surgery.

The material included two groups of 10 women undergoing diagnostic laparoscopy. General anesthesia was administered by injection of 0.1 mg fentanyl followed by infusion of propanidide-succinylcholine. The control group received no medication prior to surgery, whereas patients in the experimental group were given 5 mg bromocriptine per os. Blood samples for prolactin determinations were drawn as the patients were placed on the operating table and immediately following surgery. The association of anesthesia and surgery caused prolactin levels to rise from 10.9 +/- 3.5 to 168 +/- 18.7 ng . ml-1 in the control group (p much less than 0.001) and from 3.5 +/- 0.5 to 7.5 +/- 1.1 ng . ml-1 in the test group (p less than 0.001). A significant difference was noted between the two groups for their pre- and postoperative levels and prolactin response (p less than 0.05, p much less than 0.001 and p much less than 0.001, respectively). The proposed protocol successfully suppresses prolactin increase during surgery and constitutes a useful tool for investigating hyperprolactinemia and its consequences during this same time. Possible applications include in vitro fertilization and studies on prolactin receptor-bearing tumors.

[Comparison of midazolam and flunitrazepam as premedication administered rectally in infants]. / Comparaison du midazolam et du flunitrazépam en prémédication par voie rectale chez le nourrisson.

The present study aimed to assess the pharmaco-clinical profile of infants premedicated with rectal midazolam. The results were compared with those of a reference drug, flunitrazepam. Infants undergoing minor surgery were divided into three groups: group A (n = 30), with a mean age of 15.8 +/- 13.2 months and a mean weight of 8.6 +/- 3.3 kg, receiving 0.33 mg X kg-1 flunitrazepam; group B (n = 15), with a mean age of 11.2 +/- 10.7 months and a mean weight of 9.3 +/- 3.1 kg, receiving 0.3 mg X kg-1 midazolam; and group C (n = 30), with a mean age of 15.5 +/- 9.1 months and a mean weight of 10.7 +/- 2.5 kg, receiving 0.4 mg X kg-1 midazolam. An aqueous solution of each drug was administered with atropine sulfate (0.02 mg X kg-1) 20 min prior to induction of anaesthesia. The drug was well tolerated in 84% of cases. Statistically significant haemodynamic changes consisted of: a 9 c X min-1 decrease in heart rate (p less than 0.05) and a 12 mmHg decrease in systolic and diastolic blood pressures (p less than 0.05) in group C; a 6 mmHg decrease in systolic blood pressure (p less than 0.05) in group B. The tranquilizer action was either excellent or good in 93% of groups B and C compared with only 40% in group A (p less than 0.001 in both cases). Somnolence was attained in 60% of group A, 26.6% of group B and 30% of group C. A mask was much better accepted in group C (86.6%) than in group B (66.6%; p less than 0.05) or in group A (36.6%; p less than 0.01). Therefore, midazolam given rectally at 0.4 mg X kg-1 was better than flunitrazepam, because of a greater therapeutic effect for an equivalent rate of side effects.

[Intramuscular premedication with midazolam in infants and children]. / La prémédication intramusculaire au midazolam chez le nourrisson et l'enfant.

The useful intramuscular premedication dose of midazolam was determined in 100 children divided up in three age groups: one month to three years, 3 to 10 years, 10 to 15 years. All biometric parameters were normal for the age, and comparable between similar age groups. Haemodynamic and respiratory parameters were not altered by the premedication. The reduction in anxiety, as assessed by the child's behaviour, was good or excellent in more than 85% of cases from all age groups; it was proportional to the dose used. The doses that had, for equivalent reductions in anxiety as assessed by the chi-square test, the least hypnotic effect, were: 0.5 mg X kg-1 before three years of age, 0.4 mg X kg-1 for the 3 to 10 yr olds, and 0.25 mg X kg-1 for the 10 to 15 yr olds. This fall in dose with age, quite usual in paediatrics, was not unexpected. The level of consciousness, one hour after surgery, was always normal. No undesirable side-effect was observed. These results, together with its physical, chemical and pharmacodynamic characteristics, make midazolam a choice drug for intramuscular premedication in children, with a foreseeable use in day-care anaesthesia. The unexpected finding of an age-dependent dissociation between the reduction in anxiety and the hypnotic effect is discussed in the light of a study carried out in the adult and recent data from the literature.

[Acute hepatic steatosis of pregnancy in an Addisonian patient]. / Stéatose hépatique aiguë gravidique chez une addisonienne.

A case is reported of acute fatty liver occurring in an Addisonian woman with a twin pregnancy. It is pointed out that Sheehan's syndrome or acute fatty liver of pregnancy is an exceptional cause of jaundice in pregnancy. Its severity is due to the syndrome, associating hepatic failure and renal, pancreatic and haemorrhagic complications. The history of the pregnancy and the past medical history are of less import for the outcome. The best treatment is delivery by caesarean section, together with symptomatic treatment of the complications. In case of jaundice of unknown aetiology in late pregnancy, the advantages of an early diagnosis by transjugular hepatic biopsy are discussed.

[Cancer of the vulva: a clinical study of 46 cases]. / Cancer de la vulve: etude clinique de 46 cas.

Vulvar carcinoma is found primarily in elderly and postmenopausal women. Most patients unfortunately seek medical advice too late and only after various inadequate treatments have been applied. Radical vulvectomy is the treatment of choice in cases of epidermoid carcinoma. For the patients in the series reported who received adequate surgical treatment, the five-year survival rate was 71.4%, while for those who were inadequately treated it was only 11%.