Olivier Tirel

Effect of remifentanil with and without atropine on heart rate variability and RR interval in children.

Remifentanil can cause bradycardia either by parasympathetic activation or by other negative chronotropic effects. The high frequency (HF) component of heart rate variability (HRV) is a marker of parasympathetic activity. This study aimed to evaluate the effect of remifentanil on RR interval and on HRV in children. Forty children ASA I or II were studied after approval by the human studies committee and informed parental consent was obtained. After stabilisation at sevoflurane 1 MAC, they were randomly divided into two groups: one received a 20 μg.kg−1 atropine injection (AT + REMI) and the other ringer lactate solution (REMI). Three minutes later, a 1 μg.kg−1 bolus of remifentanil was administered over 1 min, followed by a continual infusion at 0.25 μg.kg−1.min−1 for 10 min increased to 0.5 μg.kg−1.min−1 for a further 10 min. A time varying, autoregressive analysis of RR sequences was used to estimate classical spectral parameters: low (0.04–0.15 Hz; LF) and high (0.15–0.45 Hz; HF) frequency, whereas the root mean square of successive differences of RR intervals (rmssd) was derived directly from the temporal sequence. Statistical analyses were conducted by means of the multiple correspondence analysis and with non parametrical tests. Remifentanil induced an RR interval lengthening, i.e. bradycardia, in both groups compared to pretreatment values and was associated with an increase of HF and rmssd only for the REMI group. The parasympathetic inhibition by atropine did not totally prevent remifentanils negative chronotropic effect. A direct negative chronotropic effect of remifentanil is proposed.

Transvesical Intra-Abdominal Pressure Measurement in Newborn: What Is the Optimal Saline Volume Instillation?

Objective: To determine the optimal saline volume bladder instillation to measure intravesical pressure in critically ill newborns weighing less than 4.5 kg, and to establish a reference of intra-abdominal pressure value in this population. Design: Prospective monocentric study. Setting: Neonatal ICU and PICU. Patients: Newborns, premature or not, weighing less than 4.5 kg who required a urethral catheter. Measurements and Main Results: Patients were classified into two groups according to whether they presented a risk factor for intra-abdominal hypertension. Nine intravesical pressure measures per patient were performed after different volume saline instillation. The first one was done without saline instillation and then by increments of 0.5 mL/kg to a maximum of 4 mL/kg. Linear models for repeated measurements of intravesical pressure with unstructured covariance were used to analyze the variation of intravesical pressure measures according to the conditions of measurement (volume instilled). Pairwise comparisons of intravesical pressure adjusted mean values between instillation volumes were done using Tukey tests, corrected for multiple testing to determine an optimal instillation volume. Forty-seven patients with completed measures (nine instillations volumes) were included in the analysis. Mean intravesical pressure values were not significantly different when measured after instillation of 0.5, 1, or 1.5 mL/kg, whereas measures after instillation of 2 mL/kg or more were significantly higher. The median intravesical pressure value in the group without intra-abdominal hypertension risk factor after instillation of 1 mL/kg was 5 mm Hg (2–6 mm Hg). Conclusions: The optimal saline volume bladder instillation to measure intra-abdominal pressure in newborns weighing less than 4.5 kg was 1 mL/kg. Reference intra-abdominal pressure in this population was found to be 5 mm Hg (2–6 mm Hg).

Techniques de dialyse en réanimation pédiatrique

In pediatric intensive care unit, the available modalities of acute renal replacement therapy include intermittent hemodialysis, peritoneal dialysis and continuous renal replacement therapies. No prospective studies have evaluated to date the effect of dialysis modality on the outcomes of children. The decision about dialysis modality should therefore be based on local expertise, resources available, and the patients clinical status. Poor hemodynamic tolerance of intermittent hemodialysis is a common problem in critically ill patients. Moreover, many pediatric intensive care units are not equipped with dedicated water circuit. Peritoneal dialysis, a simple and inexpensive alternative, is the most widely available form of acute renal replacement therapy. However, its efficacy may be limited in critically ill patients. The use of continuous renal replacement therapy permits usually to reach a greater estimated dialysis dose, a better control of fluid balance, and additionally, to provide adequate nutrition.

Acute renal replacement therapy in pediatrics

In pediatric intensive care unit, the available modalities of acute renal replacement therapy include intermittent hemodialysis, peritoneal dialysis and continuous renal replacement therapies. No prospective studies have evaluated to date the effect of dialysis modality on the outcomes of children. The decision about dialysis modality should therefore be based on local expertise, resources available, and the patients clinical status. Poor hemodynamic tolerance of intermittent hemodialysis is a common problem in critically ill patients. Moreover, many pediatric intensive care units are not equipped with dedicated water circuit. Peritoneal dialysis, a simple and inexpensive alternative, is the most widely available form of acute renal replacement therapy. However, its efficacy may be limited in critically ill patients. The use of continuous renal replacement therapy permits usually to reach a greater estimated dialysis dose, a better control of fluid balance, and additionally, to provide adequate nutrition.

Techniques de dialyse en réanimation pédiatrique [Acute renal replacement therapy in pediatrics]

In pediatric intensive care unit, the available modalities of acute renal replacement therapy include intermittent hemodialysis, peritoneal dialysis and continuous renal replacement therapies. No prospective studies have evaluated to date the effect of dialysis modality on the outcomes of children. The decision about dialysis modality should therefore be based on local expertise, resources available, and the patients clinical status. Poor hemodynamic tolerance of intermittent hemodialysis is a common problem in critically ill patients. Moreover, many pediatric intensive care units are not equipped with dedicated water circuit. Peritoneal dialysis, a simple and inexpensive alternative, is the most widely available form of acute renal replacement therapy. However, its efficacy may be limited in critically ill patients. The use of continuous renal replacement therapy permits usually to reach a greater estimated dialysis dose, a better control of fluid balance, and additionally, to provide adequate nutrition.