Gilles Orliaguet

Cuffed vs non-cuffed endotracheal tubes for pediatric anesthesia.

The physician undertaking pediatric anesthesia or management of the critically ill child in the pediatric intensive care unit (PICU) has great potential to cause harm to the child. Over many years, routine management of the pediatric airway has become a relatively safe undertaking and this has been achieved through the worldwide development of the speciality of pediatric anesthesia and intensive care. Any future development needs to acknowledge the large body of developmental work from past that has provided reproducible safe practice. Change must not be for change itself, and at the forefront of our practice must be the desire to provide optimized care that is evidence-based as far as possible. New techniques should be evaluated and adopted only if there is substantial evidence that innovation will be beneficial in the widest sense. This includes not only direct patient benefit but also the wider medicoeconomic arguments. The ‘pro and con’ for the direct medical benefits of cuffed vs uncuffed tubes in children remain finely poised, but the medicoeconomic arguments are irrifutable: cuffed tubes remain many times more expensive than uncuffed tubes and are likely remain so. On this basis alone it can be hard to justify the routine use of the cuffed tube provided equipoise between the two techniques remain. In contrast, on an individual basis there may be strong arguments in favor of selecting a cuffed tube provided there is justification. While enthusiasts of the cuffed tube continue to promote their potential benefits, the majority of pediatric anesthetists worldwide continue to safely use the uncuffed tube on a daily basis and find it hard to justify the large extra costs needed to change their practice when the benefits remain largely unproven. In this, the first in a new series of pro– con debates in Paediatric Anaesthesia we will examine the arguments for and against their use from the perspective of two expert views, with the goal that this will help the reader make up their own mind of whether to reconsider their current practice.

Stroke volume variation and indexed stroke volume measured using bioreactance predict fluid responsiveness in postoperative children

BACKGROUND Postoperative fluid management can be challenging in children after haemorrhagic surgery. The goal of this study was to assess the ability of dynamic cardiovascular variables measured using bioreactance (NICOM®, Cheetah Medical, Tel Aviv, Israel) to predict fluid responsiveness in postoperative children. METHODS Children sedated and mechanically ventilated, who require volume expansion (VE) during the immediate postoperative period, were included. Indexed stroke volume (SVi), cardiac index, and stroke volume variation (SVV) were measured using the NICOM® device. Responders (Rs) to VE were patients showing an increase in SV measured using transthoracic echocardiography of at least 15% after VE. Data are median [95% confidence interval (CI)]. RESULTS Thirty-one patients were included, but one patient was excluded because of the lack of calibration of the NICOM® device. Before VE, SVi [33 (95% CI 31-36) vs 24 (95% CI 21-28) ml m(-2); P=0.006] and SVV [8 (95% CI 4-11) vs 13 (95% CI 11-15)%; P=0.004] were significantly different between non-responders and Rs. The areas under the receiver operating characteristic curves of SVi and SVV for predicting fluid responsiveness were 0.88 (95% CI 0.71-0.97) and 0.81 (95% CI 0.66-0.96), for a cut-off value of 29 ml m(-2) (grey zone 27-29 ml m(-2)) and 10% (grey zone 9-15%), respectively. CONCLUSIONS The results of this study show that SVi and SVV non-invasively measured by bioreactance are predictive of fluid responsiveness in sedated and mechanically ventilated children after surgery.

Postoperative pain assessment in children: a pilot study of the usefulness of the analgesia nociception index

BACKGROUND The ability to perform objective pain assessment is very important in paediatric patients. The goal of this study was to investigate the relationship between the analgesia nociception index (ANI), which is based on the heart rate variability, and objective measurements of pain intensity in young or cognitively impaired children, after surgical or imaging procedures (control group) under general anaesthesia. METHODS On arrival in the recovery room and subsequently at 5-10 min intervals, the level of pain was rated using the FLACC pain scale (0-10). The ANI values (0-100; 0 indicating the worst pain) were recorded simultaneously. The area under the receiver operating characteristic curve (AUC) and grey zone approach were used to evaluate the performance of the ANI to detect patients with FLACC >4. Instantaneous ANI values were compared with ANI values averaged over 256 s periods of time. RESULTS All children in the surgical group (n=32) developed moderate-to-severe pain (FLACC >4). Children in the control group (n=30) exhibited minimal pain. Instantaneous ANI values were lower in children of the surgical group than in the control group [52 (sd16) vs 69 (16), P<0.001]. The AUC for the 256 s ANI recording period [0.94 (95% confidence interval 0.85-0.99)] was significantly higher than for instantaneous ANI (P<0.05). When measured for a period of 256 s, an ANI cut-off value of 56 (grey zone [58-60]) was most predictive of a FLACC ≥4. CONCLUSIONS The ANI may provide an objective measurement of acute postoperative pain, which is correlated with that measured on a FLACC scale in young or cognitively impaired children.

MORPHIT: an observational study on morphine titration in the postanesthetic care unit in children

Little information is available on the titration of morphine postoperatively in children. This observational study describes the technique in terms of the bolus dose, the number of boluses required, the time to establish analgesia, and side effects noted.

Comparaison de 3 vidéo-laryngoscopes à la laryngoscopie directe : une étude expérimentale sur mannequin nourrisson

OBJECTIVE The primary purpose of this experimental study was to compare intubation times for direct laryngoscopy with a Miller blade and for 3 VL: GlideScope® videolaryngoscope, Airtraq®, and McGrath®. METHODS Seventy-seven operators, with various experience of pediatric tracheal intubation (from none to expert), performed 10 attempts of orotracheal intubation with each device on an infant manikin. The main outcome was intubation time and secondary outcome was failure rate. RESULTS There was a significant decrease in intubation time from the first to the 10th intubation attempt with all devices (P<0.05). This decrease was no more significant following the third attempt with VL and following the fifth attempt with DL. At the time of the 10th attempt, intubation time was significantly shorter with Airtraq® as compared with all the other devices (P<0.05), but the differences were tight. Failure was significantly more frequent with DL. CONCLUSION In this infant manikin model, the learning curve of the different VL was 3 attempts and the Airtraq® VL appears the airway device enabling the quickest orotracheal intubation. These experimental results need to be confirmed by clinical studies in infants and children.

Development and validation of a risk score to predict the probability of postoperative vomiting in pediatric patients: the VPOP score

Few data are available in the literature on risk factors for postoperative vomiting (POV) in children.

Noninvasive cardiac output measurement using bioreactance in postoperative pediatric patients.

Thoracic bioreactance is a noninvasive and continuous method of cardiac output (CO) measurement that is being developed in adult patients. Very little information is available on thoracic bioreactance use in children.

Addition of droperidol to prophylactic ondansetron and dexamethasone in children at high risk for postoperative vomiting. A randomized, controlled, double-blind study

Background : The combination of dexamethasone (DEX), ondansetron (OND) and droperidol (DRO) is efficacious in preventing postoperative nausea and vomiting in adults, but has not been well assessed in children. Methods : Children undergoing elective surgery under general anaesthesia and considered at high risk for postoperative vomiting (POV) were randomly assigned to receive a combination of DEX, OND and placebo (Group A) or a combination of DEX, OND and DRO (Group B). The primary outcome was the incidence of POV during the first 24 hours after surgery. We hypothesized that the addition of DRO to the standard antiemetic prophylaxis would provide a further 15% reduction in the residual risk for POV. The secondary outcome considered was any adverse event occurring during the study. Results : One hundred and fifty-three children, aged three to 16 years, were randomized to Group A and 162 to Group B. The overall incidence of POV did not differ significantly between the two groups, with 16 patients in Group A (10.5%) and 18 in Group B (11.1%) presenting with one or more episodes of POV, P =0.86. Fewer patients presented with adverse events in Group A (2%) compared with Group B (8%), P =0.01. Drowsiness and headache were the principal adverse events reported. Conclusions : The addition of DRO to a combination of OND and DEX did not decrease POV frequency below that obtained with the two-drug combination in children at high risk of POV, but increased the risk of drowsiness. The combination of DEX and OND should be recommended in children with a high risk of POV. Clinical trial registration. NCT01739985.

Anesthésie-réanimation des processus expansifs intracrâniens de l’enfant

Resume Les processus expansifs intracrâniens les plus frequents chez l’enfant sont les tumeurs cerebrales, notamment sous-tentorielles, et les hematomes resultant d’une rupture de malformation arterioveineuse (MAV). Ils comportent un risque d’hypertension intracrânienne (HIC), directe du fait de leur volume ou par hydrocephalie obstructive du fait de l’obstacle a l’ecoulement du LCR qu’ils entrainent. Leur localisation et la compression qu’ils engendrent sur les structures de voisinage sont responsables de signes neurologiques ou generaux specifiques. Ainsi les tumeurs de la region optochiasmatique et hypophysaire comportent des risques de cecite, d’insuffisance pan-hypophysaire et de diabete insipide, les lesions de la fosse posterieure un risque d’hydrocephalie et de compression des dernieres paires crâniennes et du tronc cerebral, et les lesions sus-tensorielles un risque de deficit moteur. L’ensemble de ces donnees est a prendre en compte pour le choix des techniques anesthesiques et l’evaluation des possibilites d’exerese. Lorsque l’HIC est menacante, une induction anesthesique rapide, une intubation tracheale et une ventilation controlee ne se discutent pas. Le traitement de l’HIC repose sur une derivation de l’hydrocephalie, un traitement medical par osmotherapie, ou plus rarement une exerese de la lesion. Dans les autres cas, une anesthesie profonde, stable, respectant l’hemodynamique cerebrale est necessaire. Les installations specifiques a cette chirurgie longue comportent des risques particuliers dont le plus classique est le risque d’embolie gazeuse en position assise qui doit etre prevenu par des mesures adequates. La periode postoperatoire comporte les memes risques de complications neurologiques que la periode preoperatoire. Une surveillance rigoureuse est necessaire, le reveil et l’extubation precoce se discutent au cas par cas.

Response to Voepel-Lewis and Malviya's comment 'pain score guided morphine titration is risky and inappropriate'.

SIR—We thank Voepel-Lewis et al. (1) for their interest in our manuscript. Their first query concerns the appropriateness of using pain-score-based titration protocols to achieve analgesia in children, citing that studies conducted by their group revealed a mismatch between self-reported pain scores and self-reported need for additional analgesia in children. Such a discrepancy is unsurprising when one considers that a significant proportion of children may either be too young or unable to coherently communicate (effects of anesthesia, stress of environment etc.) medication requirements to staff. Accepting potential discrepancy between pain scores and analgesia needs, or should doctors view analgesia algorithms that rely on child feedback as ‘inappropriate’ and reject them altogether?—relying instead on fixed dose or continuous infusion regimes for morphine administration. We instinctively feel that any approach that excludes children from providing feedback about their pain is over simplistic and automatically weaker than one than does. Pain management strategies must consider the multifaceted nature of the pain experience. Sensitivity to pain varies widely and is the main contributing factor to variable opioid requirements between patients (up to tenfold for identical surgical procedures) (2–5). Additionally, genetic differences alter morphine metabolism, blood–brain barrier transfer, mu-receptor binding and therefore PK and PD of morphine between individuals (6–8). Psychosocial factors, race, environment, underlying pathology and age also play a role in pain (5). Bearing the array of factors influencing morphine requirements in mind, an approach that puts the individual at the center of its algorithm, titrating morphine to individual needs, appears the most reasonable means of achieving satisfactory and safe analgesia in adults and children (2,5). Morphine titration is used in postoperative pain management in adults (2,9,10) and equipped with behavioral pain scores (e.g. FLACC, which help distinguish pain from other distress patterns) anesthesiologists are also applying it to the pediatric population (11). VoepelLewis et al.’s assertion that ‘experts now agree that behavioral pain scores are unreliable’ must be backed up with references other than a single manuscript carried out by their own group (1,12). We are unaware of any consensus and rather believe that anesthesiologists should continue to use them, alert to other reasons for distress (e.g. hunger, anxiety etc.), and apply sound clinical judgment before administering any bolus. Regarding excessive sedation, the sedative effects of morphine are well established, with up to 60% of adults experiencing deep levels of sedation when titration protocols are employed, and it is a common reason for discontinuing morphine titration. Sedation should eagerly be sought out as the incidence of ventilatory depression has been shown to remain low if morphine administration is stopped when sedation appears (2). However, it should be noted that sedation does not necessarily herald imminent respiratory depression and that respiratory depression does not increase proportionally to degree of sedation (2). Sedation may precede pain relief, and although sedation may be attributable to pain relief, the possibility that it is due to excessive opioids requires withholding opioids, carrying out a full assessment of the patient and monitoring in the PACU. Thirdly, Voepel-Lewis et al. point out that peak brain concentration of morphine may occur 120– 160 min after dosing, and children could experience respiratory depression after the 90-min observation period (1). While peak brain effect can be delayed, the time to relative onset, that is, time to reach 80% of the maximum concentration in the effect compartment after a single i.v. injection, is between 5 and 6 min for morphine. This also makes a 5-min bolus interval safe in the PACU setting. Bearing this in mind, will help gauge when best to administer the second dose of morphine (2). Importantly, no case of respiratory depression following PACU discharge was identified in postoperative rounds designed to assess analgesia and identify complications. Next, Voepel-Lewis et al. appear to confuse criteria to stop morphine administration and PACU discharge criteria (1). In our department, children only leave the PACU once a modified Aldrete score ≥9 in association with pain relief (pain score <4) and absent nausea or vomiting has been achieved. Morphine titration was performed following major surgery, and children were usually transferred to intensive care or high dependency units. There is a major requirement to improve postoperative pain management in children, and naturally anesthesia providers must only adopt pain management strategies that are safe! Our study was designed to assess the effectiveness and safety of a protocol of morphine titration in children, and we feel our results help provide