Intérêt de la ventilation non invasive en pression positive au masque facial pour la préoxygénation chez le sujet sain : étude randomisée,en double insu,croisée

Objective

Applying an inspiratory support (AI) and a positive end expiratory pressure (PEP) could increase the effectiveness of the preoxygenation.

Study design

This randomized double blinded controlled study compares the impact on the expiratory oxygen fraction (FEO₂) of two levels of AI with PEP to a traditional preoxygenation.

Patients and methods

Twenty healthy volunteers were studied. The criteria of exclusion were a body mass index > 30, the presence of beard or moustache and the claustrophobia. Each subject went through three modes of preoxygenation during 3 minutes each in a random order: 1-spontaneous ventilation (VS), 2-preoxygenation with AI with 4 cmH₂O/PEP 4 cmH₂O (AI-4/PEP-4), 3-preoxygenation with AI with 6 cmH₂O/PEP 4 cmH₂O (AI-6/PEP-4). Subject's tolerance and leaks were also noted.

Results

The FEO₂ at the end of the 3 minutes of preoxygenation was higher (p < 0,001) with AI-4/PEP-4 (94 ± 3%) and AI-6/PEP-4 (94 ± 4%) than with technique VS (89 ± 6%). One hundred percent and 90% of the participants reached one FEO₂ = 90% with AI-4/PEP-4 and AI-6/PEP-4 respectively vs 65% with VS (p = 0.0013). The participants tolerated better the VS and the AI-4/PEP-4 than the AI-6/PEP-4. More leaks were noted with the AI-6/PEP-4 than with the VS and the AI-4/PEP-4.

Conclusion

This study shows applying AI plus PEP during preoxygenation improves its effectiveness in the healthy subjects. It also suggests that, in a population of healthy volunteers, combination AI-4/PEP-4 is preferable to AI-6/PEP-4 because so effective, but better tolerated.     

Risque barotraumatique avec des valves de non-réinhalation de Waters : étude comparative sur banc d’essai

Objective

Manual ventilation is delivered in the operating room or the intensive care unit to intubated or non-intubated patients, using non-rebreathing systems such as the Waters valve. New generation Waters valves are progressively replacing the historic Waters valve. The aim of this study was to evaluate maximal pressure delivered by these 2 valves.

Type of study

Bench test.

Material and method

Thirty-two different conditions were tested, according to 2 oxygen flow rates (10 and 20 L/min), without (static condition) or with manual insufflations (dynamic condition) and 4 valve expiratory opening pressures. The primary endpoint was maximal pressure measured at the exit of the valve, connected to a model lung and a bench test.

Results

Measured pressures were different for most evaluated conditions. Increasing oxygen flow from 10 to 20 L/min increased maximal pressure for both valves. Increasing valve expiratory opening pressure induced a significant increase in maximal pressure for the new generation valve (from 4 to 61 cmH₂O in static conditions and from 18 to 68 cmH₂O in dynamic conditions). For the historic valve, maximal pressure increased significantly but remained below 15 cmH₂O in both static and dynamic conditions.

Conclusion

Use of new generation Waters valves should be different from historic Waters valves. Indeed, barotrauma could be caused by badly adapted valve expiratory opening pressure settings.     

Variation de kaliémie après une induction en séquence rapide avec la succinylcholine chez les patients de réanimation

Objective

Evaluate the changes in potassium following rapid sequence induction with succinylcholine in critically ill-patients and determine whether hospital length of stay could influence the succinylcholine-induced hyperkaliemia.

Study design

Prospective and observational study.

Patients and methods

After approval by our local ethical committee, we prospectively included 36 patients admitted from more than 24 hours in ICU and who required succinylcholine for rapid tracheal intubation (1 mg/kg). Serum potassium was measured before, 5 and 30 min after succinylcholine. The incidence of life-threatening hyperkaliemia (≥ 6.5 mmol/L) was noted.

Results

We could observe significant and transient increase in serum potassium (median increase of 0.45 [0.20–0.80] mmol/L at five minutes). A significant relationship was observed between the ICU length of stay and arterial potassium increase (r = 0.37, P < 0.05). From the ROC curve, a threshold of 12 days had an 86% sensitivity and 69% specificity in discriminating patients in whom the potassium increase was more than 1.5 mmol/L.

Conclusion

Induction with succinylcholine is followed by significant but transient hyperkaliema. The ICU length of stay before giving succinylcholine could influence significantly the amplitude of potassium increase.     

Efficacy of preoxygenation with non-invasive low positive pressure ventilation in obese patients: Crossover physiological study

Objective

The impact of non-invasive positive pressure ventilation (NIPPV), which is a combination of inspiratory positive airway pressure (IPAP) and positive end expiratory pressure (PEEP), on the effectiveness of preoxygenation in obese patients was evaluated.

Design

Randomized, controlled, double blinded, crossover study comparing NIPPV vs. tidal volume breathing (TVB) with regard to the expiratory O₂ fraction (FeO₂).

Patients and methods

Thirty participants with body mass index (BMI) greater or equal to 30 kg/m² scheduled for elective surgery were included. Patients with facial hair, and airway anomalies were excluded. Each patient underwent 3 minutes 100% O₂ preoxygenation with the two following methods in a random order: 1: TVB; 2: NIPPV (4 cmH₂O IPAP + 4 cmH₂O PEEP). Primary outcome was FeO₂ after 3 minutes. Secondary outcomes were the number of patients reaching FeO₂ greater or equal to 90%, tidal volume, respiratory rate, and patient comfort on a 4-point scale.

Results

No differences between methods were found regarding the FeO₂ change with time or after 3 minutes (89 ± 6% with TBV vs. 91 ± 4% with NIPPV). FeO₂ greater or equal to 90% was reached more frequently with NIPPV (80%) than with TVB (60%) (P = 0.008). Tidal volume (m ± SD) was larger throughout preoxygenation with TBV (837 ± 440 mL) than with NIPPV (744 ± 368 mL), (P = 0.0005). Respiratory rate did not differ between regimens. Patient comfort was good and similar.

Conclusion

This study suggests that providing a positive pressure of 4 cmH₂O throughout inspiration and expiration during preoxygenation in obese patients provided benefits with regard to the FeO₂.     

Effets de l’hydroxyzine sur l’acceptation du masque à l’induction de l’enfant

Objective

To evaluate the effectiveness of hydroxyzine as a premedication agent for the acceptance of facial mask during induction of general anaesthesia in children.

Study design

Prospective randomized single-blind study including ASA 1 and 2 children, aged between 1 and 9 years and undergoing outpatient surgery.

Patients and methods

Patients were randomly allocated to receive orally either 1 mg/kg hydroxyzine (G1) or water 0.1 ml/kg (G2) one hour before induction of standardized inhalational anaesthesia. Tolerance of facial mask was assessed with a 3-points scale (good, moderate or poor). Chi-square and Student's t-test were used in statistical analysis; p values less than 0.05 were considered statistically significant.

Results

One hundred patients were included (G1 = 49, G2 = 51). Demographic data were similar in both groups. Acceptance of facial mask was significantly better in G1 than in G2 (p = 0,002).

Conclusion

Hydroxyzine provided better acceptance of facial mask than placebo during induction of general anaesthesia in children.     

Effet d’une dose unique intramusculaire de déxaméthasone sur la douleur après circoncision. Étude randomisée contrôlée

Objective

To assess the effect of a preoperative single dose of dexamethasone associated with penile block on pain after circumcision.

Study design

Prospective randomized controlled study.

Patients and methods

Forty male children aged 2 to 5 years, scheduled for circumcision under general anaesthesia, combined with penile block, were randomized into two groups. The dexamethasone group received dexamethasone 0.4 mg/kg preoperatively. The control group received the same volume of normal saline. Data compared between two groups were: postoperative pain assessed by the Objective Pain Scale collected in the recovery room, at 8 and 24 hours postoperatively (h0, h8 and h24), time to first analgesic request and the quality of sleep on the first postoperative night.

Results

Pain scores at h0 were similar between the two groups. The dexamethasone group showed significantly lower pain scores at h8 [0 (0–1) vs. 2 (0–3); P = 0.04] and h24 [0 (0–0) vs. 0 (0–1); P = 0.02]. The time to first analgesic administration was also significantly delayed in the dexamethasone group compared to the control group (240 vs 180 min; P = 0.035). The quality of sleep was also better in children in the dexamethasone group (P = 0.018).

Conclusion

This study showed that the combination of a preoperative single dose of dexamethasone 0.4 mg/kg with penile block significantly improves the quality of analgesia after circumcision.     

Enquête VENTILOP. Enquête sur la ventilation mécanique peropératoire

Introduction

Mechanical ventilation can initiate ventilator-associated lung injury and postoperative pulmonary complications. The aim of this study was to evaluate (1) how mechanical ventilation was comprehended by anaesthetists (physician and nurses) and (2) the need for educational programs.

Methods

A computing questionnary was sent by electronic-mail to the entire anaesthetist from Alsace region in France (297 physicians), and to a pool of 99 nurse anaesthetists. Mechanical ventilation during anaesthesia was considered as optimized when low tidal volume (6–8 mL) of ideal body weight was associated with positive end expiratory pressure, FiO₂ less than 50%, I/E adjustment and recruitment maneuvers.

Results

The participation rate was 50.5% (172 professionals). Only 2.3% of professionals used the five parameters for optimized ventilation. Majority of professionals considered that mechanical ventilation adjustment influenced the patients’ postoperative outcome. Majority of the professionals asked for a specific educational program in the field of mechanical ventilation.

Discussion

Only 2.3% of professionals optimized mechanical ventilation during anaesthesia. Guidelines and specific educational programs in the field of mechanical ventilation are widely expected.     

Impact de la diminution d’utilisation du protoxyde d’azote sur la consommation d’agents halogénés

Objective

Nitrous oxide (N₂O) toxicity and its impact on pollution lead to restrict its use. A decrease of N₂O consumption should increase the hypnotic inhaled consumption. This monocentric study estimated consumptions and costs of halogenated agents (HA) and N₂O over 5 years when the N₂O consumption was reduced.

Study design

Retrospective from a computerized database.

Patients

Between 2006 and 2010, 34,097 procedures were studied after two meetings exposing the risks of the N₂O.

Methods

At the end of anesthesia, consumptions of hypnotic agents (millilitres transmitted by the injectors and the blender) were archived in the database. The annual consumption of agents was obtained by adding the individual consumptions, then divided by the annual number of cases. The costs were given by the hospital pharmacy from invoices.

Results

N₂O consumption per anesthesia constantly decreased during the study, from 75.1 L by act to 22.7 L. The sum of the annual consumptions of N₂O and air did not change suggesting that total fresh gas flow remained stable. Between 2006 and 2010, the sevoflurane consumption by act increased by 25%, from 16.5 to 20.6 mL, and desflurane consumption by 37%, from 46.1 to 63.1 mL by patient. The costs of the administration of hypnotic agents remained stable.

Conclusion

N₂O consumption decrease had an impact on the consumption of HA. The cost reduction of the N₂O was counterbalanced by the increase of halogenated vapor cost. The profit of the ecological impact of the reduction in N₂O use could be quantified.     

The increasing incidence of adolescent bariatric surgery

Background

Morbid obesity continues to be a significant problem within the United States, as overweight/obesity rates are nearing 33%. Bariatric surgery has had success in treating obesity in adults and is becoming a viable treatment option for obese adolescents.

Methods

We studied 1615 inpatient admissions for children ≤ 20 years of age undergoing a bariatric procedure for morbid obesity in 2009 using the Kids' Inpatient Database (KID). Patients had a principal diagnosis of obesity and a bariatric procedure listed as one of their first 5 procedures. Procedures (open gastric bypass, laparoscopic gastric bypass, sleeve gastrectomy, laparoscopic gastroplasty, and laparoscopic gastric band) and complications were defined by ICD-9 codes.

Results

There were 90 open gastric bypasses, 906 laparoscopic gastric bypasses, 150 sleeve gastrectomies, 18 laparoscopic gastroplasties, and 445 laparoscopic gastric bandings. The length of stay for each procedure was 2.44, 2.20, 2.33, 1.10, and 1.02 days, respectively (P < 0.001). The complication rates were 3.3%, 3.5%, 0.7%, 0.0%, 0.2%, respectively (P = 0.004).

Conclusions

Bariatric surgery is an increasingly utilized option for the treatment of morbid obesity among adolescents. The procedures can be performed safely as evidenced by low complication rates. Additional long-term follow-up is necessary.     

Pulmonary acute respiratory distress syndrome: positive end-expiratory pressure titration needs stress index

Background

The heterogeneity of lung injury in pulmonary acute respiratory distress syndrome (ARDS) may have contributed to the greater response of hyperinflated area with positive end-expiratory pressure (PEEP). PEEP titrated by stress index can reduce the risk of alveolar hyperinflation in patients with pulmonary ARDS. The authors sought to investigate the effects of PEEP titrated by stress index on lung recruitment and protection after recruitment maneuver (RM) in pulmonary ARDS patients.

Materials and methods

Thirty patients with pulmonary ARDS were enrolled. After RM, PEEP was randomly set according to stress index, oxygenation, static pulmonary compliance (Cst), or lower inflection point (LIP) + 2 cmH₂O strategies. Recruitment volume, gas exchange, respiratory mechanics, and hemodynamic parameters were collected.

Results

PEEP titrated by stress index (15.1 ± 1.8 cmH₂O) was similar to the levels titrated by oxygenation (14.5 ± 2.9 cmH₂O), higher than that titrated by Cst (11.3 ± 2.5 cmH₂O) and LIP (12.9 ± 1.6 cmH₂O) (P < 0.05). Compared with baseline, PaO₂/FiO₂ and recruitment volume were significantly improved after PEEP titration with the four strategies (P < 0.05). PaO₂/FiO₂ and recruitment volume were similar when using PEEP titrated by stress index and oxygenation but higher than that titrated by Cst and LIP. Compared with baseline, lung compliance increased significantly when PEEP determined by Cst, but there was no difference of Cst in these four strategies. There was no influence of PEEP titration with the four strategies on hemodynamic parameters.

Conclusions

PEEP titration by stress index might be more beneficial for pulmonary ARDS patients after RM.     

La discipline anesthésie-réanimation et les pôles d’activité médicale (PAM) : résultats d’une enquête auprès des CHU et CHG

Objective

To know: (1) how French public services of anaesthesia and critical care (ACC) have applied the new principles of hospital management and (2) whether or not it has impacted the different components of ACC.

Study design

National questionnaire at the end of 2008, i.e., after 2 years of new hospital management.

Material

Heads of ACC services in general (GH) and university hospitals (UH).

Methods

Eighteen closed questions and open opinions analyzed. Comparisons of percentages (Chi² – Yates): linear correlation.

Results

Percentages of responses were 70% (n = 51) for UH and 37% (n = 146) for GH. The new management principles were mainly applied. The different clinical and academic components of the ACC specialty (ACC, emergency medicine, pain management) mainly remained associated in UH. In GH, the new management induced constant and various changes. They were mainly judged as defeating the object of the ACC speciality in GH, especially in those of lower and mild sizes.

Conclusion

The general tendency is that the ACC specialty was able to maintain the family ties of its different components in the UH. However, this principle was not a cornerstone of the new management in the GH.     

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 cmH₂O. The cuff pressure was then monitored every 10 minutes and adjusted to be between 15 and 35 cmH₂O. 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.     

Comparaison prospective et randomisée de la morphine nébulisée versus la péridurale thoracique dans la prise en charge de la douleur des traumatisés thoraciques

Introduction

Successful management of pain reduces morbidity and improves patient satisfaction of patient after a chest trauma. The purpose of the study was to evaluate the efficacy of the respiratory administration of nebulized morphine in such patients.

Patients and methods

Patients were included in this prospective and randomized study patients to receive either nebulized morphine in group M or a mixture of bupivacaine-fentanyl by epidural route. In group M, patients received nebulized morphine every 30 minutes until the second hour then every 4 hours during 48 hours. In the thoracic epidural analgesia group (group P) they received a mixture of 0.125% bupivacaine and 0.115% of fentanyl continuously infused at the rate of 7 ml/h during 48 hours. The main criterion of judgment was the analgesic effects of analgesic regimen with EVA < 4. Sedation, haemodynamic and respiratory parameters were continuously recorded, as adverse side effects were they occurred. Statistical comparisons were performed with Chi², Fisher or Student t-test when appropriate (p < 0.05).

Results

Forty patients were randomized in two groups. Groups were not different regarding the demographic parameters. Analgesia was effective in both groups (NS). Sedation, hemodynamic and respiratory parameters were not different between groups. No side effect was noted in groups.

Conclusion

Nebulized morphine was an analgesic technique as effective as epidural bupivacaine-fentanyl in our series. This non-invasive route of administration of morphine appears to be useful to treat pain after a chest trauma.     

Expérience d’un système de recueil d’évènements indésirables en anesthésie

Objectives

This article summarizes functioning and results of anaesthesia adverse effects reporting system over its first 18 months, from August 2006 to February 2008.

Study design

Monocentric retrospective study.

Methods

Reporting system is available 24/24 h, 7/7 to every employee with an individual password. A committee with anaesthesiologists, nurses and risk management engineer examines every notification by two months. We evaluated number of reports, type of reporter, type of dysfunction reported and solutions. Numerical data are compared with a Student t test or X² test. A p-value of less than 0.05 g being considered as statistically significant.

Results

One hundred and eighty-five reports were registered for the first 18 months (1% of anesthesia activity) with a slowdown with time (p = 0.02). Eighty-six percent of the statements were made by anesthesiologists, but some physicians had never reported. Malfunctions shared between different services (identity, operating room organisation) are rarely solved (67%) compared to specific anesthesia problems (93%) (p < 0.001).

Conclusion

The reporting system is simple and available but some professionals don’t declare, generating reporting bias. This network underlines major general dysfunctions (identity) but ways to solve are limited to date.     

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.     

Différence artérioveineuse du contenu en O2, saturation veineuse mêlée en O2 ou index cardiaque en postopératoire de chirurgie cardiaque : sont-ils équivalents ?

Objective

To study the concordance of cardiac index (CI), mixed venous oxygen saturation (SvO₂) and the arterial-mixed venous O₂ content difference, i.e.: C(a–v)O₂, postoperatively to cardiac surgery. We hypothesized that significant discrepancies would be measurable between C(a–v)O₂ and SvO₂, and CI, because the latter two indices encompass less metabolic components than the former.

Design

Analysis of variables collected as part of routine care.

Patients

Eighty anesthetized patients receiving mechanical ventilation after heart surgery.

Measurements and results

Using linear regression of SvO₂ versus C(a–v)O₂ (Reg 1) and CI versus C(a–v)O₂ (Reg 2), respectively we found that CI = 2.2 L min⁻¹ m⁻² and SvO₂ = 70% were equivalent to C(a–v)O₂ = 5 ml/100 ml. The error reflected by the vertical scatter of points around the regression line, once normalized was 3.24 times greater in Reg 2 than in Reg 1.

Conclusions

The correspondence of CI, SvO₂ and C(a–v)O₂ values observed in a population of patients studied immediately after scheduled heart surgery match those reported in critically ill patients. SvO₂ and furthermore CI induced a sizeable scatter of points around regression line. Accordingly, they appear as a lesser estimate of the flow/metabolism balance that may at best be inferred from C(a–v)O₂.     

Titration morphinique intraveineuse en salle de surveillance post-interventionnelle (SSPI) après chirurgie bariatrique sous cœlioscopie

Objective

There is limited information available regarding intravenous (IV) morphine admistration in obese patients in PACU. The aim of this study was to compare two IV morphine titration (IMT) regimen in two surgical centers.

Study design

Observational study.

Patients

Laparoscopic bariatric surgery in one private (Saint-Grégoire Clinic) and one public (University Hospital of Amiens) surgical center.

Methods

A strict and common protocol of IMT was implemented if PACU of both centers according to the recommendations of the French Society of Anaesthesia and Intensive Care. When pain score increased to > 30, IMT was titrated every 5 min in 3 mg increments until pain relief (VAS ≤30 mm). Pain level, dose of morphine (per total and ideal body weight), effectiveness, and side events were recorded.

Results

Data were recorded for 159 adult patients (129 women). Mean age and BMI were 42 ± 12 yrs and 43.8 ± 6.9 kg/m². Ninety-eight patients were eligible for IMT regimen but only 76 patients received IV morphine (47.8 %). Mean dose was 7.3 mg ± 3.5 mg [1–19 mg], (60.4 μg/kg and 115.8 μg/kg). IMT was less frequent, mean dose was greater (8.6 ± 4.2 vs 6.2 ± 2.9 mg) and number of patients with pain relief was higher (73.7 vs 35.6 %) in the public hospital. No severe adverse events have been recorded and there was no difference in both centers regarding these events.

Conclusion

Implementation of a IMT regimen in PACU was not associated with effective pain relief after laparoscopic surgery in obese patients.     

Infiltration peropératoire de lévobupivacaïne après césariennes : étude randomisée en double insu contre placebo

Objectives

The efficacy of single-dose intraincisional infiltration with levobupivacaine in postoperative analgesia and chronic pain after caesarean sections is unknown.

Study

A placebo-controlled double-blind randomized trial.

Patients and methods

After ethical approval, and written inform consent, 140 women scheduled for a caesarean section were randomly assigned and received 30 mL of levobupivacaine 0.5% (L group) or saline (placebo-P group) into their wound. The primary endpoint was morphine consumption (using intravenous morphine patient-controlled analgesia) for the first 24 h after surgery. At 1 h to 48 h, side effects, pain at rest and pain 2 months later were recorded.

Results

All included patients had similar demographic and surgical characteristics. The morphine consumption was significantly lower in the L group at h6, h8 and h12 (considering both total intake and each request). At h4, the mean total morphine consumption was 25 (12) mg in the L group versus 31 (14) mg in the P group (P = 0.05). Time until discharge and side effects including nausea-vomiting (14 vs 20%), wound scar complications (6 vs 8%) and chronic pain after 2 months (25% in both groups complained of small pain, and 75% no pain) were similar between the two groups (P > 0.05).

Conclusion

Single-dose local infiltration of levobupivacaine 0.5% reduced opioid requirement at 12 h, with no difference after 24 h. www.clinicaltrials.com, number: NCT00621907.