The benefits of experiencing flow through distracting activities: flow reduces preoperative anxiety in children before surgery, but not postoperative difficulties.

BACKGROUND: Distraction is a classic anxiety management strategy in preoperative setting with children: distracting activities take children's attention away from threatening clues. What is less clear is the differential effectiveness of this technique depending on the task, and the degree of children engagement with the distracting task. The present work examined the role of flow (state of intense concentration and absorption in the distracting task) on children's preoperative anxiety. METHODS: Anxiety and flow in a distracting activity were measured in a sample of 100 children (3 to 10 years-old), at two critical moments of the preoperative period prior to ambulatory surgery under general anesthesia (phase 1: up to separation from the parents; phase 2: up to general anesthesia). Common negative postoperative outcomes were also measured. RESULTS: As expected, the analysis showed a negative association between the mean level of flow in the distracting activity during waiting periods and the preoperative anxiety of children at critical moments in the two phases (although there was no effect on postoperative recovery). CONCLUSION: These findings demonstrate the importance of considering the degree of engagement in the distracting activity to understand the effectiveness of this strategy. The results may help provide guidance for better clinical application of this method.

Does the participation of a senior plastic surgeon improve conditions of hospitalisation in craniosynostosis repair surgery?

INTRODUCTION: The real impact of the participation of other surgical specialties together with neurosurgeons on perioperative care in craniosynostosis repair surgery has not been determined. The purpose of this study was to determine whether the participation of a second senior surgeon (plastic surgeon) during surgical repair of pediatric monosutural craniosynostosis improved perioperative medical care. MATERIAL AND METHODS: The authors retrospectively reviewed 2 cohorts of patients who had consecutively undergone primary repair surgery for trigonocephaly and unicoronal craniosynostosis. Infants were operated on by a single senior pediatric neurosurgeon before December 2017, and with the collaboration of a senior plastic surgeon after January 2018. RESULTS: Overall, 60 infants were included in the study: 29 in group 1 (single surgeon, 2011-2017), and 31 in group 2 (pair of surgeons, 2018-2021). Median surgery time was significantly shorter in group 2 than group 1: 180 vs. 167minutes; P=0.0045. There was no significant difference between the 2 groups in blood loss or intra/postoperative packed erythrocyte transfusion. Postoperative drain output was significantly lower in group 2. Median length of hospital and intensive care stay were significantly shorter in group 2, by 1 and 2 days, respectively; P<0.0001. Volume of infused solution, diuresis, immediate postoperative hemoglobin level, hematocrit, hemostasis (platelet count, fibrinogen, prothrombin time and activated partial thromboplastin time), and return to oral feeding did not differ from one group to the other. CONCLUSION: Results confirmed our impression of an improvement in perioperative medical care. However, the role of surgical experience and the influence of the medical/nursing staff must not be minimized in these complex surgical procedures.

Importance of tranexamic acid in pediatric monosutural craniosynostosis surgery.

OBJECTIVE: Tranexamic acid (TXA) is an antifibrinolytic drug that has achieved significant reduction in perioperative blood loss and the quantity of blood transfused in many pediatric surgical procedures, without morbidity. Despite the accumulation of evidence regarding its effectiveness in craniosynostosis repair surgery, TXA is not unanimously employed by pediatric neurosurgery teams. The purpose of this study was to evaluate the impact of the routine use of TXA in a homogeneous population of children who underwent open surgery for monosutural craniosynostosis. METHODS: The authors retrospectively reviewed 3 cohorts of patients that were subdivided from 2 cohorts surrounding the initiation of TXA (group 1, TXA- [2008-2011] and group 2, TXA+ [2011-2013]) and a third cohort of more recent patients (group 3, TXA+ [2016-2017]). TXA was administered using the same protocol comprising a loading dose of 10 mg/kg over 15 minutes after induction of general anesthesia followed by a 10 mg/kg per hour infusion until skin closure. Patients in all 3 groups underwent similar standardized procedures for scaphocephaly, trigonocephaly, and unicoronal craniosynostosis by the same pediatric neurosurgeon. RESULTS: Overall, 102 infants were included in the study: 32 infants in group 1, 36 in group 2, and 34 in group 3. Significant reductions in transfusion of packed erythrocytes (PE) and fresh-frozen plasma (FFP) were observed between the TXA- and TXA+ time periods. The median volume of PE transfusion was reduced by > 50% with the use of TXA (42.8 mL/kg in the TXA- group vs 20.0 in the TXA+ groups, p < 0.0001). Reduction in PE transfusion was 100% postoperatively in the TXA+ groups (20.0 mL/kg in the TXA- group vs 0.0 in the TXA+ groups, p < 0.0001). The median volume of FFP transfusion was reduced by 100% with the use of TXA (12.8 mL/kg in the TXA- group vs 0.0 in the TXA+ groups, p < 0.0001). All children in group 1 received a transfusion, whereas 3 children (8%) and 7 children (20%) in groups 2 and 3, respectively, did not. Significant reductions in postoperative drain output were also noted between the TXA- and TXA+ time periods. The total hospital length of stay was significantly lower in the TXA+ groups (p < 0.0001). CONCLUSIONS: Use of TXA reduced blood loss and the need for transfusions but also decreased the hospital length of stay and, thus, minimized overall medical care costs. Intraoperative administration of TXA in craniosynostosis repair surgery should be routinely used in all centers that practice these procedures.

Simplification of first-line antibacterial regimen for complicated appendicitis in children is associated with better adherence to guidelines and reduced use of antibiotics.

Acute appendicitis in children requires early surgery and short-course antibiotics active against Enterobacteriaceae and anaerobes. Although an aminoglycoside-containing three-drug regimen has been used successfully for decades, simpler regimens with similar efficacy are increasingly used. This study evaluated the impact of a switch from the combination of cefotaxime, metronidazole and gentamicin (regimen 1) to piperacillin/tazobactam (regimen 2) as first-line regimen for complicated acute appendicitis in children. In total, 171 children were enrolled [median (IQR) age, 10 (6-13) years], treated with regimen 1 (n = 80) or regimen 2 (n = 91) following surgery for complicated acute appendicitis. The two groups were comparable except for surgical approach (through laparoscopy in 46% vs. 88% for regimens 1 and 2, respectively; P < 0.001). Post-operative complications and duration of hospital stay were similar. Deviations from antibacterial treatment protocol decreased from 36% (29/80) to 14% (13/91) (P < 0.001), with a dramatic reduction in antibacterial treatment duration from median (IQR) of 15 (12-16) days to 5 (5-8) days (P < 0.001). Post-operative intra-abdominal abscess developed in 32 children (18.7%). Female sex (OR = 2.76, 95% CI 1.18-6.48; P = 0.02) and sepsis/septic shock on admission (OR = 4.72, 95% CI 1.12-19.97; P = 0.035) were independently associated with post-operative intra-abdominal abscess, but not antibacterial regimen. This study shows that simplification of first-line antibacterial regimen for complicated appendicitis in children was associated with reduced protocol deviation, reduced duration of antibiotics, and similar outcomes (post-operative complications and duration of hospital stay).

Effectiveness and complications of ultrasound-guided subclavian vein cannulation in children and neonates.

BACKGROUND: The ultrasound (US)-guided supraclavicular approach to subclavian vein (Sup-SCV) catheterisation in children has recently been described and evaluated in a small cohort. The aim of this study was to assess this technique in a large paediatric cohort including neonates. METHODS: We conducted a prospective observational study between November 2010 and December 2013 which included 615 children divided into two groups according to their weight: Group 1≤5kg (n=124), Group 2>5kg (n=491). All procedures were performed under general anaesthesia by an anaesthesiologist or a supervised resident. The success rates of catheter insertion, the number of punctures required, the procedure time, and the complication rates were analysed. RESULTS: Sup-SCV catheterisation was successful in 98% of the cases and was higher in Group 2 than in Group 1 (99.4% versus 92.7%, P<0.001). The success rate after the first attempt was higher and the incidence of multiple attempts (≥3 punctures) was lower in Group 2 than in Group 1 (84.2% versus 64.5%, P<0.001 and 4.5% versus 19.4%, P<0.001). The success rate was similar between right and left cannulations (P=0.404), and according to physician experience (P=1.000). Procedure time was fast in both groups with a median time for all procedures of 40 seconds [30-90]. Among the procedures recorded, only five arterial punctures and no cases of pneumothorax were observed. CONCLUSION: US-guided Sup-SCV catheterisation appears to be fast and safe in children and neonates, even if it remains a little more difficult to achieve in lower-weight patients.

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).

Evaluation of the pediatric post anesthesia discharge scoring system in an ambulatory surgery unit.

INTRODUCTION: To optimize the care pathway for children scheduled for ambulatory surgery, a pediatric postanesthetic discharge scoring system (Ped-PADSS) was developed from a score used in adults. The objective of this study was to evaluate this score prospectively on a cohort of children who had a day case surgical procedure. MATERIALS AND METHODS: This was a single center prospective observational study. Inclusion criteria were predefined as follows: children aged 6 months-16 years at the time of the study, with a scheduled day surgery. Discharge was validated by Ped-PADSS scores ≥9, obtained at one hour intervals, after the return from the operating room and with the agreement of the surgeon. The duration of postoperative hospitalization was compared with data collected before the implementation of the score using the Student's t-test. RESULTS: From February to July 2012, 1060 children were included. One hour after the return from the operating room, 97.2% of children were dischargeable using Ped-PADSS. Two hours after the return from the operating room, 99.8% of children were dischargeable. The median postoperative hospital stay (n = 1041) was reduced by 69 min compared to the median stay before using the output score (n = 150) (P < 0.01). CONCLUSION: The Ped-PADSS score allows for the majority of children to be discharged 1 h after their return from the postanesthesia care unit. Children who were discharged using the Ped-PADSS score returned home in safe and optimal conditions.

Hypnosis and dental anesthesia in children: a prospective controlled study.

The authors of this prospective study initially hypothesized that hypnosis would lower the anxiety and pain associated with dental anesthesia. Thirty children aged 5 to 12 were randomly assigned to 2 groups receiving hypnosis (H) or not (NH) at the time of anesthesia. Anxiety was assessed at inclusion in the study, initial consultation, installation in the dentist's chair, and at the time of anesthesia using the modified Yale preoperative anxiety scale (mYPAS). Following anesthesia, a visual analogue scale (VAS) and a modified objective pain score (mOPS) were used to assess the pain experienced. The median mYPAS and mOPS scores were significantly lower in the H group than in the NH group. Significantly more children in the H group had no or mild pain. This study suggests that hypnosis may be effective in reducing anxiety and pain in children receiving dental anesthesia.

French current practice for ambulatory anesthesia in children: a survey among the French-speaking Pediatric Anesthesiologists Association (ADARPEF).

BACKGROUND: This survey aims to describe current practice in ambulatory care among pediatric anesthesiologists in France. METHODS: Members of the French-speaking Pediatric Anesthesiologists Association (ADARPEF) were sent a questionnaire examining the proportion of pediatric ambulatory anesthesia practiced by each responder, the level of adherence to pediatric ambulatory Anesthesia guidelines, and responder consensus in decision making when faced with common case scenarios in pediatric ambulatory anesthesia. For the latter, consensus was defined as a > 80% opinion. RESULTS: One hundred and forty-five pediatric anesthesiologists replied (43%). Ambulatory anesthesia appears underused in France. Recent French pediatric ambulatory anesthesia guidelines are being applied. Postoperative pain is poorly managed. The choice of scheduling children for ambulatory anesthesia appears to be more heavily influenced by practitioners' subjective evaluation than evidence from the literature. CONCLUSION: A better commitment for ambulatory care must be found among anesthesiologists. Further studies are required to improve coherence, safety, and efficiency of children selection for ambulatory anesthesia.

Electrocardiographic and hemodynamic effects of intravenous infusion of bupivacaine, ropivacaine, levobupivacaine, and lidocaine in anesthetized ewes.

BACKGROUND AND OBJECTIVES: Neural blockade techniques are associated with a risk of acute cardiac toxicity after accidental intravenous (IV) injection of local anesthetics. The aim of this study was to compare electrocardiographic (ECG) and hemodynamic (HEM) effects induced by IV infusion of local anesthetics in an anesthetized ewe model. METHODS: Thirty-two anesthetized ewes received IV bupivacaine (BUPI), ropivacaine (ROPI), or levobupivacaine (S-BUPI) at an equimolar dose, or lidocaine (LIDO) at a 3-fold higher rate (n = 8 in each group). RR, PR, QRS, and QT intervals (QTc), changes (Delta) in systolic and diastolic arterial pressure (SAP and DAP), and in myocardial contractility (dP/dt), were assessed every 30 seconds for 7 minutes. From main ECG variables (RR, PR, QRS, QT), we proposed to use multiple correspondence analysis and hierarchical ascending classification to explore the structure of statistical dependencies among those measurements, and to determine the different patterns of ECG and HEM changes induced by infusion of BUPI, ROPI, S-BUPI, and LIDO. RESULTS: Graphic representation of multiple correspondence analysis associated BUPI with the most pronounced modifications in ECG and HEM variables, followed by in decreasing order ROPI, S-BUPI, and LIDO. Comparisons of clusters identified by hierarchical ascending classification confirmed this classification for ECG variables. Ventricular tachycardia occurred only in the BUPI group. CONCLUSIONS: In our anesthetized ewe model, high dose IV infusion of BUPI induced the most marked changes in RR, PR, QRS, QT, QTc intervals, DeltaSAP, and DeltadP/dt. ROPI altered ECG variables less than BUPI but more than S-BUPI. LIDO was associated with the smallest changes.

Delta waves differently modulate high frequency components of EEG oscillations in various unconsciousness levels.

In this paper we investigate the modulation properties of high frequency EEG activities by delta waves during various depth of anesthesia. We show that slow and fast delta waves (0-2 Hz and 2-4 Hz respectively) and high frequency components of the EEG (8-20 Hz) are correlated with each other and there is a kind of phase locking between them that varies with depth of anesthesia. Our analyses show that maximum amplitudes of high frequency components of the EEG signal are appeared in different phases of slow and fast delta waves when the concentration of Desflurane and Propofol anesthetic agents varies in a patient. There are some slight differences in using slow and fast components of delta waves. For instance, when depth of anesthesia changes, biphasic responses of the EEG have more influences on results of the fast delta wave method. In addition, this method obtains more robust and less noisy results compared with the slow delta wave method. Since phase angle between fast EEG oscillations and delta waves indicates the status of information processing in the brain and it changes in various unconsciousness levels, it may improve the performance of other classic methods of determining depth of anesthesia.

Epidural, intrathecal pharmacokinetics, and intrathecal bioavailability of ropivacaine.

BACKGROUND: Ropivacaine is used by the epidural route for postoperative pain management with various neuraxial techniques. Given the widespread use of these techniques and the relative paucity of data on spinal disposition of local anesthetics, we evaluated through an experimental animal model, the spinal disposition of ropivacaine, allowing further studies of factors influencing their intrathecal bioavailability. METHODS: Sheep received an IV bolus dose of ropivacaine (50 mg), and 1 wk after, an intrathecal dose of ropivacaine (20 mg) followed 3 h later by epidural ropivacaine (100 mg). A simultaneous microdialysis technique was used to measure epidural and intrathecal drug concentrations after both epidural and intrathecal administrations. RESULTS: Absorption-time plots showed a large variability in the systemic absorption after both intrathecal and epidural administration, with an apparent faster systemic absorption after intrathecal administration. In the intrathecal space, the elimination clearance was around three-times higher than the distribution clearance. In the epidural space, the relative contribution of elimination and distribution to ropivacaine disposition was different, indicating a more pronounced influence of the distribution process. The intrathecal bioavailability after epidural administration was 11.1% +/- 7.6%. CONCLUSIONS: Using an animal model, we showed that drug dispositions in the intrathecal and epidural compartments are different, and that the intrathecal bioavailability of ropivacaine after epidural administration is low, and highly variable.

An evaluation of a polyamine-deficient diet for the treatment of inflammatory pain.

Polyamines are thought to be involved in the regulation of numerous metabolic and electrophysiological processes in the nervous system. In this study we evaluated the effect of a synthetic polyamine-deficient diet on pain in a carrageenan (Car)-induced inflammatory rat model. Inflammation was induced with a unilateral subcutaneous injection of Car in a plantar hindpaw in rats fed without (control group) or with (deficiency group) a polyamine-deficient diet. Ipsilateral and contralateral hyperalgesia was evaluated using the Randall-Sellito pressure test. Heart rate changes were also recorded under general anesthesia. Then, the effects of a bupivacaine sciatic nerve block and subcutaneous injection of naloxone or ketamine were evaluated for Car-induced hyperalgesia. Data were analyzed using analysis of variance followed by unpaired Student's t-test (significance P < 0.05). Before Car injection, no significant difference was observed in response to mechanical stimuli between the control and the deficiency groups (n = 114 in pooled data). Car injection induced significant ipsilateral and contralateral hyperalgesia in the control groups, whereas a significant analgesic effect appeared in the deficient groups on both the ipsilateral and contralateral hindpaws. This analgesic effect was confirmed by the electrocardiogram recording that showed a significant increase in heart rate in the control group after Car injection compared with the deficiency group that showed a decrease in heart rate under general anesthesia. Bupivacaine sciatic nerve block had no significant effect on hypoalgesia phenomena induced by polyamine deficiency. Naloxone administration had no effect in the control group but reversed the analgesic effect in the deficiency group. Ketamine administration induced a significant analgesic effect in the control group and partly reversed the analgesic effect in the deficiency group. In conclusion, a synthetic polyamine-deficient diet had a significant general analgesic effect on Car-induced mechanical hyperalgesia. The mechanism of analgesic action remains to be elucidated.

Designing a planar vector field to investigate the role of a slow variable in an enhanced mean-field model during general anesthesia.

Local mean-field models (MFMs) describe regional brain activities by some connected differential equations. In an overall view, constituting variables of these differential equations can be divided to very fast, fast and slow variables. In this article we propose a method that can be used to determine role of a slow variable in behavior of MFMs. Very fast variables can be adiabatically removed from the equations. Isoclines of fast and slow variables and their corresponding vector field can provide valuable information about model behavior and role of the slow variable in it. The vector field of our interested MFM that is an enhanced MFM designed specially for general anesthesia, is a 3D field (one slow and two fast variables) and it is not so convenient for visually inspecting the role of the slow variable in this model. To afford this problem we design a 2D (planar) vector filed that only considers the slow variable and one of the fast variables.

Premedication in children: hypnosis versus midazolam.

BACKGROUND: The main objectives of premedication in children are to facilitate the separation from the parents, to reduce preoperative anxiety, to smooth the induction of anesthesia and to lower the risk of postoperative behavioral disorders. The most common technique is sedative premedication with midazolam. Hypnosis enables a state of relaxation to be achieved and has never been evaluated as a premedication technique. The aim of the present study was to evaluate the efficacy of hypnosis on anxiety and perioperative behavioral disorders versus midazolam. METHODS: Fifty children from 2 to 11 years of age were randomized into two groups: group H received hypnosis as premedication; group M were given 0.5 mg x kg(-1) midazolam orally, 30 min before surgery. Preoperative anxiety was evaluated using the Modified Yale Preoperative Anxiety Scale (mYPAS) score when arriving in the department (T1), when entering the operating room (T2), and when fitting the facemask (T3). Postoperative behavioral disorders were evaluated using the Posthospitalization Behavioral Questionnaire (PHBQ) at days 1, 7 and 14. RESULTS: The two groups showed no significant difference preoperatively with the PHBQ: (M) 21 (17-25) vs (H) 20 (8-25) and mYPAS score: (M) 28 (23-75) vs (H) 23 (23-78). The number of anxious children was less during induction of anesthesia in the hypnosis group (T3: 39% vs 68%) (P < 0.05). Postoperatively, hypnosis reduced the frequency of behavior disorders approximately by half on day 1 (30% vs 62%) and day 7 (26% vs 59%). CONCLUSIONS: Hypnosis seems effective as premedication in children scheduled for surgery. It alleviates preoperative anxiety, especially during induction of anesthesia and reduces behavioral disorders during the first postoperative week.

Congenital diaphragmatic hernia: prenatal diagnosis permits immediate intensive care with high survival rate in isolated cases. A population-based study.

OBJECTIVES: To estimate the prognosis of prenatally diagnosed isolated congenital diaphragmatic hernia (PDICDH) treated with 'immediate planned care' (IPC) between 1999 and 2003 in Eastern Brittany. METHODS: The prognosis of PDICDH was compared with the prognosis of the other live-born CDH, either prenatally undiagnosed or not having had IPC. IPC consisted in prenatal lung maturation with corticosteroids, elective caesarean section at 37 weeks, immediate intubation, surfactant, high- frequency ventilation or oscillation, nitric oxide, intravenous prostacyclin, anaesthesia and haemodynamic support. Surgical repair was performed in the NICU 34 h after birth. RESULTS: The incidence of CDH was 0.8 per thousand with a prenatal diagnosis rate of 27/30 (90%), leading to a termination of pregnancy in nine cases. Ten CDH were associated with other malformations. IPC in PDICDH was performed in 12 cases. The survival rate of PDICDH with IPC was 11/12 versus 1/9 in CDH with no IPC or no prenatal diagnosis (p < 0.01). Logistic regression analysis showed that IPC was determinant for survival (p < 0.01). CONCLUSION: Prenatal diagnosis of isolated CDH treated with immediate planned care is associated with a high survival rate. This suggests that prenatal diagnosis associated with specifically adapted postnatal procedure may improve the prognosis of isolated CDH.

Comparison of heart rate response to an epinephrine test dose and painful stimulus in children during sevoflurane anesthesia: heart rate variability and beat-to-beat analysis.

BACKGROUND AND OBJECTIVES: During regional anesthesia, various stimuli leading to an adrenergic response can occur. However, simulation of an epidural test dose by using intravenous administration of epinephrine (EPI) has always been compared with an intravenous saline infusion as the control. The aim of this study was to evaluate the possibility of distinguishing in children the effect on HR by an intravascular epinephrine infusion and a painful stimulus, using heart rate variability (HRV) and beat-to-beat analysis of HR. METHODS: Thirty American Society of Anesthesiologists physical status P I children who required elective surgery were studied. At 1 minimum alveolar concentration (MAC) of sevoflurane, electrocardiogram was recorded continuously. Systolic blood pressure (SBP) was measured every minute. Measurements were performed after an intravenous administration of 0.5 microg/kg of epinephrine and during a small skin surgical incision (SI). Time-varying auto-regressive modeling of the interpolated RR sequences was performed for estimating power spectrum (msec(2)). The HF bands were defined by (0.15-0.4 Hz). RESULTS: Median (range) age and weight of all children were 3.5 (1-10) years and 16 (9-30) kg. EPI produced a lower increase in HR than did SI. SBP increased significantly more than did after SI. T-wave amplitude increased significantly after EPI but not after SI. Sixty seconds after the first change in HR, a secondary decrease (in comparison to control value) can be detected with EPI in contrast to SI. HF spectral power increased significantly after EPI administration but decreased after SI. The sensitivity, specificity, and positive and negative predictive value were respectively for DeltaHR >10 beats per minuteof 56%, 26%, 43%, and 38%; for DeltaSBP >15 mm Hg of 60%, 86%, 81%, and 67%; and for DeltaT-wave amplitude >25% of 86%, 73%, 76%, and 84%. Using detection of the secondary decrease of HR, 60 seconds after the first change in HR, sensitivity, specificity, and positive and a negative predictive value were respectively 96%, 100%, 100%, and 96%. CONCLUSIONS: Detection of the secondary HR decrease, 60 seconds after the first change in HR, allows us to distinguish the effects of a painful stimulus from those related to the epinephrine test dose at 1 MAC of sevoflurane. This secondary HR decrease induced by epinephrine appears primarily because of a compensatory increase in parasympathetic tone.

The relationship between expired concentration of sevoflurane and sympathovagal tone in children.

UNLABELLED: In children, sevoflurane depresses parasympathetic tone during induction more than halothane. The effects of sevoflurane on parasympathetic activity could explain the difference in heart rate (HR) changes described between infants and children. In this study, we sought to determine the relationship between the end-tidal concentration of sevoflurane and sympathetic and parasympathetic tone in children by spectral analysis of RR intervals. Thirty-three children, ASA physical status I, who required elective surgery were studied. In 10 children (Group A), recordings were performed while gradually decreasing the inspired sevoflurane concentration from 8% to the beginning of clinical awakening. In 23 other children (Group B), recordings were performed while children were awake and at a steady-state of 1 and 2 minimum alveolar anesthetic concentration of sevoflurane. A time-varying autoregressive modeling of the interpolated RR sequences was performed, and spectral density in low-frequency (LF; 0.04-0.15 Hz) and high-frequency (HF; 0.15-0.55 Hz) bands was calculated. In Group A, HR slowing paralleled the decrease in expired sevoflurane concentration. Conversely, the decrease in expired concentration of sevoflurane led to an increase in systolic blood pressure (SBP), HF, LF, and LF/HF. The increase in LF/HF preceded the increase in HF. In Group B, the baseline HF power spectrum and normalized values HFnu (HFnu = HF/LF + HF) were significantly increased in children older than 3 yr. Changes in HR induced by sevoflurane were negatively correlated with baseline HF and HFnu (R(2) = 0.6; P < 0.001). These results demonstrate that withdrawal of parasympathetic tone is the main determinant for the change in HR induced by sevoflurane. IMPLICATIONS: The effects of sevoflurane on parasympathetic activity could explain the difference in heart-rate changes described between infants and children during induction. This study describes the changes in heart rate and its variability induced by sevoflurane in children and shows that these changes are related to parasympathetic tone before the induction of anesthesia.

Perinatal management and outcome of prenatally diagnosed congenital diaphragmatic hernia: a 1995-2000 series in Rennes University Hospital.

OBJECTIVES: To assess the prognosis of prenatally diagnosed congenital diaphragmatic hernia (CDH) during the years 1995-2000 in order to improve prenatal counselling. METHODS: Retrospective study of all 31 cases of women with prenatally diagnosed CDH. RESULTS: Nine pregnancies (29%) were terminated and two fetuses (6%) were stillborn. Ten fetuses (32%) had associated anomalies (four Fryns' syndrome) and four (13%) had underlying chromosomal anomalies. Twenty pregnancies were continued. Seven babies died before surgery either immediately in the delivery room (five between 1 and 45 min), or during the 'stabilisation period' (two babies, 7 and 21 h). Three babies presented with trisomy 18, Fryns' syndrome or transposition of the great arteries with microdeletion 22q11. Thirteen babies had the defect repaired (median 18 h, range 4-72 h) and 12 survived. Mechanical ventilation was required for a median of 12 days. One survivor has cerebral palsy. CONCLUSION: Of 31 prenatally diagnosed CDH cases 38% are alive, of 20 ongoing pregnancies 60% are alive, and of 13 babies who underwent surgery 92% are alive. No baby with associated malformations survived. These numbers need to be known by each member of the counselling team in order to give parents adequate information to make their decision.

Extrapolation of cardiac index from analysis of the left ventricular outflow velocities in children: implication of the relationship between aortic size and body surface area.

BACKGROUND: It has recently been reported in critically ill patients that a linear relationship exists between cardiac index (CI) measured with thermodilution and mean aortic blood flow velocity (MAFV). This hypothesis can be validated mathematically only if the aortic area (AA index) indexed to body surface area (BSA) remains constant and if the relationship between aortic diameter (PhiAo) and BSA is nonlinear. However, several other equations have described the relationship between BSA and, respectively, PhiAo and aortic area (AA) in children. The aim of this study was to determine if the relationships calculated between BSA and aortic size in children (without left ventricular outflow tract abnormality) could validate the hypothesis that MAFV and CI are well linked linearly, leading to its use to determine CI. METHODS: Two hundred and thirty-two measurements performed in 126 children and infants were retrospectively analysed. PhiAo was measured in the long axis view at the annulus using two-dimensional mode echocardiography with a 5-MHz transducer. Various linear and nonlinear relationships between BSA and, respectively, PhiAo, PhiAoindex, AA and AAindex were determined based on a nonlinear regression method with a model as follows: y=a(xc) + b. The comparisons between regressions were conducted based on the estimation error. RESULTS: The relationships between PhiAo and BSA appeared nonlinear and was well described by: PhiAo=2.96(BSA1/4) - 1.31 with a non-zero y-intercept and PhiAo=1.64(BSA1/2) with a zero y-intercept. In contrast, the relationships between AA and BSA were linear. The AAindex was not linked to BSA and can be considered as constant. The coefficient a of the equation appeared similar to those obtained mathematically with the relationship previously described between MAFV and CI. CONCLUSIONS: The hypothesis that CI can be extrapolated to the measurement of MAFV appears valid as regards the relationships calculated between aortic size and BSA in children without left ventricular outflow tract abnormality.