Is the sitting or the prone position best for surgery for posterior fossa tumours in children?

BACKGROUND: The aim of this study was to compare complications in children operated for posterior fossa tumours in the sitting position with those in the prone position. METHODS: We retrospectively assessed the perioperative course of posterior fossa tumour (PFT) surgery according to the operating position. Sixty children were operated in the sitting position (SP) and 19 in the prone position (PP). Preoperative data were not different between groups. RESULTS: Patients in the PP group received a larger median (95% confidence interval) volume of intraoperative blood transfusion than patients in the SP group [200 (20-325) versus 0 (0-80) ml, P=0.04]. Intraoperative complications, as well as severe perioperative complications were more frequent in the PP group (P=0.01). The median duration of tracheal intubation [20 (18-24) versus 36 (18-72) h, P=0.037], of ICU stay [2 (2-3) versus 4 (2-5) days, P=0.02] and of hospital stay [11 (9-12) versus 14 (10-20) days, P=0.02] was longer in the PP group compared with the SP group. CONCLUSIONS: PFT surgery in the sitting position in children is not associated with an increased number or severity of perioperative complications, while the postoperative course appears better in this position.

Postal survey of cuffed or uncuffed tracheal tubes used for paediatric tracheal intubation.

A postal survey of the use of cuffed or uncuffed tracheal tubes for tracheal intubation in children and infants was performed to investigate the criteria used for deciding the choice of tube and the manner of inflating the cuff in the case of use of a cuffed tracheal tube (CTT). From 200 questionnaires despatched, replies were received from 130 paediatric anaesthesiologists (response rate 65%). In paediatric practice, the CTT was routinely used by 25% of respondents for more than 80% of their patients, while more than 37% of respondents use them in less than 20% of the cases. The three main criteria used for inflating a cuff were: (i) the presence of a leak, (ii) the type of surgery associated with the presence of a leak and (iii) the patient's age associated with the type of surgery and the presence of a leak. These criteria were specified, respectively, by 32%, 24% and 18% of the respondents. The cuff was inflated in response to a leak in 18% of the cases and as a response to a pressure manometer in 15% of the cases. Few paediatric anaesthesiologists use a cuffed tracheal tube routinely for tracheal intubation in children, and fewer actually use a pressure monitoring device, while it is suggested that the cuff pressure should be monitored in case of CTT.

Perioperative blood salvage during surgical correction of craniosynostosis in infants.

Surgical correction of craniosynostosis in infants is a very haemorrhagic procedure. The aim of this study was to determine whether the perioperative use of the continuous autotransfusion system (CATS) would reduce homologous transfusion during repair of craniosynostosis. Two groups of patients were studied according to the availability of the CATS in our hospital. The control group had surgery before the system was introduced and the study group had operations subsequently. Use of CATS was associated with a significant decrease in the median (95% confidence interval) volume of homologous blood transfused [413 (250-540) ml in the control group versus 317 (150-410) ml in the CATS group, P = 0.02] and in the median (95% confidence interval) number of packed red cell units transfused [2 (1-2) in the control group versus 1 (1-2) in the CATS group, P = 0.04] in the perioperative period. Use of CATS is associated with a reduction in homologous transfusion during the surgical correction of craniosynostosis in infants.

Emergency management of deeply comatose children with acute rupture of cerebral arteriovenous malformations.

PURPOSE: To assess the impact of emergency management on mortality and morbidity of acute rupture of cerebral arteriovenous malformations resulting in deep coma in children, and the factors predicting outcome. METHODS: Retrospective chart review of 20 children with a Glasgow Coma Scale < or = 8 with acute hemorrhagic stroke from a cerebral arteriovenous malformation rupture was conducted. Protocol included: early resuscitation with tracheal intubation and ventilation after induction of anesthesia with sufentanil, and benzodiazepine, and mannitol 20% or hypertonic saline 7.5% infusion for life-threatening brain herniation. Radiological exploration was limited to contrast-enhanced CT scan preceding immediate surgical decompression. Postoperatively, children were deeply sedated and intracranial pressure monitoring allowed titration with osmotherapy, vasopressors, hyperventilation or barbiturate coma to control cerebral perfusion pressure. Analysis used stratification of the type of hemorrhage (supra or infra tentorial), location (intraparenchymal and subarachnoid, intraparenchymal and intraventricular or intraventricular alone) and relationship between presentation, evolution with resuscitation, type of cerebral lesion, and outcome. RESULTS: Patients had a severe initial presentation (median Glasgow Coma Scale five), eight had unilateral and eight bilateral third nerve palsy. Compressive hematoma in supratentorial localisation represented 75% of the cases. Global mortality was 40%. Persistence of mydriasis after resuscitation increased mortality to 75%. Massive intraventricular flooding was associated with increased mortality. Good functional outcome was achieved in survivors. CONCLUSION: Acute rupture of an AVM can result in rapidly progressing coma. Emergency management with early resuscitation, minimal radiological exploration before rapid surgical decompression results in a mortality rate of 40%, but a good functional outcome can be expected in the survivors.

Predictive factors of outcome in severely traumatized children.

UNLABELLED: To identify risk factors associated with death in traumatized children, we prospectively studied 507 consecutive patients (7+/-4 yr) admitted to a level I pediatric trauma center over a 3-yr period. Pediatric Trauma Score (PTS), Glasgow Coma Scale (GCS) score, and Injury Severity Score (ISS) were calculated. Age, injury mechanism, injury pattern, and initial critical care were recorded. Univariate and multivariate analyses were performed for potential risk factors associated with mortality. Receiver operating characteristic curves were used to determine threshold values of variables identified by univariate analysis. Most children suffered from blunt trauma (99.6%), and head trauma was noted in 85%. Median values (range) of GCS scores, PTS, and ISS were 10 (3-15), 7 (-4 to 12), and 16 (3-75), respectively. The mortality rate was 12%. Using multivariate analysis, death was significantly associated with an ISS > or = 25 (odds ratio [OR] 22.2, 95% confidence interval 2.8-174.9), GCS score < or = 7 (OR 4.77, 1.8-12.7), emergency blood transfusion > or = 20 mL/kg (OR 4.3, 2.1-9.1), and PTS < or = 4 (OR 3.7, 1.4-9.7). An ISS > or = 25, GCS score < or = 7, immediate blood transfusion > or = 20 mL/kg, and PTS < or = 4 were significant and independent risk factors of death in an homogenous population of severely injured children. The probability of traumatic death was therefore 0 (95% confidence interval 0-0.0135) in children with no one of these threshold values in the four predictive factors and 0.63 (95% confidence interval 0.47-0.76) in those children with all the threshold values. IMPLICATIONS: Methods used for evaluating outcome of trauma patients have essentially been derived from adult series, and attempts to apply them to children have usually been inaccurate. Univariate and multivariate analyses were performed to identify risk factors associated with death in severely traumatized children, and Receiver operating characteristic curves were used to determine threshold values.

Non-invasive aortic blood flow measurement in infants during repair of craniosynostosis.

We have assessed the potential clinical benefit of a new echo-Doppler device (Dynemo 3000) which provides a continuous measure of aortic blood flow (ABF) using an aortic flowmeter and a paediatric oesophageal probe, during repair of craniosynostosis in infants under general anaesthesia. The data recorded included: ABFi (i = indexed to body surface area), stroke volume (SVi), systemic vascular resistance (TSVRi), pre-ejection period (PEP), left ventricular ejection time (LVET), mean arterial pressure (MAP), heart rate (HR) and central venous pressure (CVP). Data were collected: before (T1) and 3 min after skin incision (T2), at the time of maximal haemorrhage (T3) and at the end of the procedure (T4). Twelve infants (aged 7.0 (range 6-12) months) were included. ABFi, MAP and CVP were significantly lower at T3 compared with T1 (2.0 (0.8) vs 3.0 (0.8) litre min-1 m-2, 46.1 (5.8) vs 65.2 (8.9) mm Hg and 2.8 (1.6) vs 5.2 (2.1) mm Hg; P < 0.05). PEP/LVET ratio was significantly lower at T2 compared with T1 (0.25 (0.05) vs 0.30 (0.06)) and increased at T4 (0.36 (0.04); P < 0.05). These preliminary results suggest that this non-invasive ABF echo-Doppler device may be useful for continuous haemodynamic monitoring during a surgical procedure associated with haemorrhage in infants.

End-tidal carbon dioxide during out-of-hospital cardiac arrest resuscitation: comparison of active compression-decompression and standard CPR.

STUDY OBJECTIVES: To compare the maximal end-tidal carbon dioxide pressure (ETCO2 peak) values obtained during standard (S-CPR) and active compression-decompression CPR (ACD-CPR) during prolonged resuscitation in out-of-hospital cardiac arrest. DESIGN: Prospective, randomized crossover study. SETTING: City with a population of 3.5 million, served by an emergency medical service system providing advanced cardiac life support. PARTICIPANTS: Patients with nontraumatic out-of-hospital cardiac arrest. INTERVENTIONS: Patients were randomly assigned to receive first, for a period of 3 minutes, either ACD-CPR or S-CPR; then the two methods were alternated. ETCO2 was continuously monitored and computed. MEASUREMENTS AND RESULTS: Sixteen patients (48 +/- 20 years old) were included; in 12, return of spontaneous circulation was achieved, and 5 were admitted alive to the hospital. A statistically significant increase in ETCO2 peak was obtained with ACD-CPR (27.6 +/- 3 mm Hg) compared with S-CPR (15.6 +/- 2.2 mm Hg). No major adverse effect possibly related to ACD-CPR was observed. CONCLUSION: This prospective study suggests that ACD-CPR may improve cardiac output compared with S-CPR.

Ventilatory effects of active compression-decompression in dogs.

STUDY OBJECTIVE: To determine the ventilatory effect of active compression-decompression CPR and to compare it with two other techniques, standard manual cardiac massage and mechanical cardiac massage. DESIGN: Prospective, randomized laboratory investigation. PARTICIPANTS: Mongrel dogs. INTERVENTIONS: Nine adult mongrel dogs were anesthetized, intubated, and mechanically ventilated. They were instrumented to measure arterial pressure, esophageal pressure, airway pressure, end-tidal carbon dioxide concentration, and minute ventilation. RESULTS: After induction of ventricular fibrillation, three sequences of cardiac massage were performed randomly during mechanical ventilation, standard cardiac massage, mechanical cardiac massage, and active compression-decompression technique. The animals then were disconnected from the ventilator, and the three sequences were performed again. Active compression-decompression created negative minimum esophageal pressures and significantly decreased the minimum airway pressure as compared with the other techniques. Whatever the ventilatory condition, minute ventilation was increased dramatically during active compression-decompression. CONCLUSION: In this model of cardiac arrest, an important increase in minute ventilation was observed during active compression-decompression. This effect was significantly greater than the increases observed with other techniques of cardiac massage and was related to the negative pressure generated by active decompression.

Hemodynamic, gas exchange, and hormonal consequences of LBPP during PEEP ventilation.

Hemodynamic, gas exchange, and hormonal response induced by application of a 25- to 40-mmHg lower body positive pressure (LBPP), during positive end-expiratory pressure (PEEP; 14 +/- 2.5 cmH2O) were studied in nine patients with acute respiratory failure. Compared with PEEP alone, LBPP increased cardiac index (CI) from 3.57 to 4.76 l X min-1 X m-2 (P less than 0.001) in relation to changes in right atrial pressure (RAP) (11 to 16 mmHg; P less than 0.01). Cardiopulmonary blood volume (CPBV) measured in five patients increased during LBPP from 546 +/- 126 to 664 +/- 150 ml (P less than 0.01), with a positive linear relationship between changes in RAP and CPBV (r = 0.88; P less than 0.001). Venous admixture (Qva/QT) decreased with PEEP from 24 to 16% (P less than 0.001) but did not change with LBPP despite the large increase in CI, leading to a marked O2 availability increase (P less than 0.001). Although PEEP induced a significant rise in plasma norepinephrine level (NE) (from 838 +/- 97 to 1008 +/- 139 pg/ml; P less than 0.05), NE was significantly decreased by LBPP to control level (from 1,008 +/- 139 to 794 +/- 124 pg/ml; P less than 0.003). Plasma epinephrine levels were not influenced by PEEP or LBPP. Changes of plasma renin activity (PRA) paralleled those of NE. No change in plasma arginine vasopressin (AVP) was recorded. We concluded that LBPP increases venous return and CPBV and counteracts hemodynamic effects of PEEP ventilation, without significant change in Qva/QT. Mechanical ventilation with PEEP stimulates sympathetic activity and PRA apparently by a reflex neuronal mechanism, at least partially inhibited by the loading of cardiopulmonary low-pressure reflex and high-pressure baroreflex. Finally, AVP does not appear to be involved in the acute cardiovascular adaptation to PEEP.

Lower body positive pressure vs. dopamine during PEEP in humans.

The application of lower body positive pressure (LBPP) of approximately 40 Torr was used to increase cardiac index (CI) in eight patients with acute respiratory failure (ARF) during positive end-expiratory pressure (PEEP) ventilation. The effects of LBPP on hemodynamics and gas exchange were compared with those of dopamine at the same level of CI without blood volume expansion. LBPP increased CI via an increase in stroke index without associated tachycardia, whereas dopamine combined both effects. A positive linear relationship (r = 0.82) was evidenced between CI and right atrial pressure (Pra) during application of LBPP according to the Frank-Starling mechanism, whereas dopamine did not increase Pra. The increase in CI with dopamine was associated with a significant rise in venous admixture (r = 0.84, P less than 0.001), whereas no such effect was observed with LBPP (r = 0.088). Changes in venous admixture were directly related to changes in mixed venous O2 pressure (PVO2) in both situations (r = 0.733, P less than 0.01), but the increase in PVO2 was more pronounced with dopamine than with LBPP (P less than 0.04). We conclude that LBPP can effectively counterbalance peripheral venous blood pooling during PEEP ventilation in humans with ARF and that changes in PVO2 appear as a major determinant of venous admixture in this setting.