Prospective validation of a new airway management algorithm and predictive features of intubation difficulty.

BACKGROUND: Some patients have features that indicate possible difficulty with direct laryngoscopy for tracheal intubation. Prediction of the likely outcome and selection of patients for an enhanced management algorithm would reduce the possible harm from failed intubation attempts. METHODS: Adult elective patients were assessed for seven features associated with difficult direct laryngoscopy, ranked in difficulty from 0 to 3. For a patient with at least one Class 3 feature, or two or more features of class 1 or higher, the enhanced management used a channelled videolaryngoscope Airtraq™ instead of a Macintosh laryngoscope. A long flexible angulated stylet and a flexible fibrescope would be used as the second and third steps. For patients with lesser difficulty scores, a Macintosh laryngoscope was used. Outcomes of enhanced management were analysed. Logistic regression and Random Forest algorithm, using the ranks of the predictive features, were used to predict difficulty during enhanced management. RESULTS: We prospectively studied 16 695 patients. We selected 1501 (9%) for enhanced management, and tracheal intubation was successful in all of them. Of these, 73% were intubated in less than 30 s, and only 4.5% required more than 4 min for intubation. Progression to the second and third steps of enhanced management was predicted by restriction of mouth opening and reduced cervical spine mobility. CONCLUSIONS: An enhanced management algorithm allowed successful tracheal intubation of all patients with anticipated difficult laryngoscopy. The need to combine the use of a stylet and a fibrescope with the Airtraq™ could be predicted with a high degree of certainty.

Influence of the cuff pressure on the swallowing reflex in tracheostomized intensive care unit patients.

BACKGROUND: Because recovery of an efficient swallowing reflex is a determining factor for the recovery of airway protective reflexes, we have studied the influence of the tracheostomy tube cuff pressure (CP) on the swallowing reflex in tracheotomized patients. METHODS: Twelve conscious adult intensive care unit (ICU) patients who had been weaned from mechanical ventilation were studied. Simultaneous EMG of the submental muscles with measurement of peak activity (EMGp) and amplitude of laryngeal acceleration (ALA) were performed during reflex swallows elicited by pharyngeal injection of distilled water boluses during end expiration. After cuff deflation, characteristics of the swallowing reflex (latency time: LaT, EMGp, and ALA) were measured at CPs of 5, 10, 15, 20, 25, 30, 40, 50, and 60 cm H(2)O. RESULTS: LaT and CP were linearly related (P<0.01). CP was inversely correlated (P<0.01) to both ALA and EMGp. CONCLUSIONS: We demonstrated that LaT, EMGp, and ALA of the swallowing reflex were influenced by tracheostomy tube CP. The swallowing reflex was progressively more difficult to elicit with increasing CP and when activated, the resulting motor swallowing activity and efficiency at elevating the larynx were depressed.

[Wound infiltration with local anesthetics for postoperative analgesia. Results of a national survey about its practice in France]. / Infiltrations d'anesthésiques locaux pour l'analgésie postopératoire chez l'adulte. Résultats d'une enquête nationale de pratique.

BACKGROUND AND OBJECTIVE: Local wound infiltration is a component of multimodal postoperative (p.o.) analgesia. Its implementation in current clinical practice remains unknown. Pain and Regional Anesthesia Committee of the French Anaesthesia and Intensive Care Society (Sfar) aimed to appraise its practice. METHOD: Postal sample survey based on representative sample of national activity were sent to heads of anaesthesiology departments. The questionnaires included 36 items on single-shot and continuous wound infiltrations (CWI) with considerations about modality of administration, drugs and development limitations. Results in mean [CI95 %]. RESULTS: Response rate was 32 % (n=120). Sample was in accordance with national representation of health institutions. Local infiltration was included in 85 % [79-91] of the p.o. analgesia protocols. Regardless of the surgery, single-shot wound infiltration and CWI were used in more than 50 % of the patients by respectively 58 % [49-67] and 18 % [11-25] of the responders. However, a significant part of the surgeons remained reluctant to CWI. Lack of information and fear of septic complications were the most reported barriers. Peritoneal instillation after laparoscopy was rarely performed, in contrast with intra-articular infiltration after knee arthroscopy, performed systematically or very frequently by 60 % [50-70] of the responders. CONCLUSION: The practice of local wound infiltration for p.o. analgesia seems presently well established, especially for single-shot injections. CWI is less commonly performed. Several surgical reluctances remain to be overcome. Better information about effectiveness and safety are likely to still improve their practices.

Spread of local anesthetic during an ultrasound-guided interscalene block: does the injection site influence diffusion?

BACKGROUND: During interscalene block (ISB) placement, ultrasound guidance (USG) enables the practitioner to measure the spread of local anesthetic around the nerve trunks or roots, and to adjust the needle position in order to optimize diffusion. Moreover, USG helps determine the best injection level, i.e. the point from which diffusion gives the most complete brachial plexus block. The aim of this study was to compare C5 and C6 level injections and to determine which level allows the best diffusion. METHODS: Sixty randomized patients scheduled for shoulder surgery were divided into two groups. In group C5, injection was directed toward C5 while in group C6, the C6 nerve root was targeted. Block performance time was recorded. The onset of motor and sensory block of each nerve distribution was evaluated every 10 min over a 30-min period. RESULTS: The average time taken to perform a nerve block was 6.2+2.6 min in Group C6 and 6.0+2.1 min in Group C5 (NS). At 30 min, the number of patients with a satisfactory musculocutaneous and axillary nerve block was not notably greater in either group. By contrast, a significantly higher success rate was observed for other nerves in the C6 group as compared to the C5 group: ulnar nerve block: 93% vs. 19%, radial nerve block: 96% vs. 28%, median nerve block: 96%, vs. 69%. CONCLUSIONS: During USG ISB placement, injection below the C6 level provided the same efficiency in analgesia after shoulder surgery as an injection cranial to the C5 nerve root but a greater success rate of anesthesia in all distal nerve areas. This technique could be very interesting for trauma cases as an alternative to a supraclavicular block and offers a high success rate and is simple to perform, potentially promoting wide use and quicker learning for beginners.

[Fast-tracking and regional anaesthesia: preliminary feasibility study]. / Fast-tracking en anesthésie locorégionale périphérique: étude préliminaire de faisabilité.

OBJECTIVE: The monitoring in the post-anaesthesia care unit (PACU) improves the safety, the comfort and the analgesia of patients. At present, studies suggest the possibility to bypass the PACU according to the principle of fast-tracking (FT). The aim of this study was to evaluate the feasibility and the safety of a simulated protocol of FT after a regional anaesthesia. PATIENTS AND METHODS: Seven hundred patients were prospectively included in this study over a period of 6 months. METHODS: The Withes' scoring system was used for determining when patients could be safely discharged from PACU. We added a variable concerning the monitoring of surgical site. A minimum score of 14 was required on arrival to the PACU to consider a FT. The success rate of blocks, the use of sedation or general anaesthesia were noted. Adverse events were recorded. RESULTS: The success rate of blocks was 93 %. The score was higher than 14 in 98 % of case on arrival to the PACU. Thirteen adverse events were reported before surgery and/or operating room. No adverse events were reported during the stay in the PACU. CONCLUSION: Regional anaesthesia seems to be an appropriate principle to fast-track the PACU. It could be a way to reduce health care costs, and can offer solution for the PACU congestion problem. In France, the fast-tracking is a marginal concept without any support regulatory. An evolution to such a practice could be considered.

The learning process of the hydrolocalization technique performed during ultrasound-guided regional anesthesia.

BACKGROUND: Because poor echogenicity of the needle remains a safety issue, we decided to analyze the learning process of the hydrolocalization technique (Hloc) performed to continuously identify needle-tip anatomical position during many ultrasound-guided regional anesthesia procedures. METHODS: Ten senior anesthesiologists naïve to the Hloc agreed to participate in the study. They were requested to perform 40 out-of-plane (OOP) approach ultrasound-guided axillary blocks (AB) each using the Hloc. The Hloc, which is a needle-tip localization principle, was performed by means of repetitive injections of a small amount of a local anesthetic solution (0.5-1 ml) under an ultrasound beam. Details of the learning process and skill acquisition of the Hloc were derived from the following parameters: the duration of block placement, a measure of the perceived difficulty of needle-tip visualization, a measure of block placement difficulty, and the amount of local anesthetics solution required for the technique. RESULTS: Four hundred ABs were performed. The success rate of an ultrasound-guided AB was 98%. The Hloc was successful in all patients. Skill acquisition over time of the Hloc was associated with a significant reduction of both the duration and the perceived difficulty of ABs placement. Apprenticeship data revealed that 20 blocks were required to successfully place AB within 5 min in most cases using the Hloc. CONCLUSION: The Hloc performed during the OOP approach of ultrasound-guided regional anesthesia is a simple technique with a relatively short learning process feasible for efficient placement of ABs.

[Ultrasound guided regional anaesthesia: an effective method for cleaning the probes]. / Anesthésie locorégionale périphérique sous échographie: efficacité de stratégie de décontamination de la sonde.

OBJECTIVES: The objective of this study was to determine if the ultrasound probe can act as a vector for cross-infection and to compare two cleaning methods for ultrasound probes in order to limit or control the transmission risk. STUDY DESIGN: Prospective study. PATIENTS AND METHODS: The first part of the study (P1) was conducted to evaluate the possibility of the ultrasound probe to serve as a source of cross-contamination. Thirty blocks were placed under ultrasound guidance in elective outpatients. After each procedure (Proc), the ultrasound probe was decontaminated/cleaned using either an antiseptic solution spray (AS: n=15) or just wiped with two dry paper sheets (DP: n=15), in a randomly assigned order. Bacteriological samples were collected before and after each decontamination/cleaning methods and inoculated on a chocolate agar plates. The second part of the study (P2) was conducted to compare the effectiveness of two cleaning methods for ultrasound probes. The ultrasound probes were exposed to a large inoculum of three bacteria (Inoc). They were then cleaned/decontaminated using either DP (n=10) or AS (n=10), in a randomly assigned order. Bacteriological samples were collected before and after each cleaning/decontamination methods and inoculated on a chocolate agar plates. RESULTS: During P1, after Pro, all probes were found to be sterile before and after both AS and DP. During P2, after Inoc, all probes were found infected (CFU>150) but were considered sterile (CFU<10) after both DP and AS. CONCLUSION: The results of this study suggest that the risk of cross-infection during ultrasound guidance in locoregional anaesthesia is really low. Our data suggest that wiping ultrasound probe with two dry paper sheets is an adequate cleaning method to prevent cross-contamination risk.

[Evaluation of the learning curve of residents in localizing a phantom target with ultrasonography]. / Evaluation de la courbe d'apprentissage des internes pour l'échoguidage sur un fantôme.

INTRODUCTION: Few information are available regarding the learning curve in ultrasonography and even less for ultrasound-guided regional anesthesia. This study aimed to evaluate in a training program the learning curve on a phantom of 12 residents novice in ultrasonography. MATERIAL AND METHODS: Twelve trainees inexperienced in ultrasonography were given introductory training consisting of didactic formation on the various components of the portable ultrasound machine (i.e. on/off button, gain, depth, resolution, and image storage). Then, students performed three trials, in two sets of increased difficulty, at executing these predefined tasks: adjustments of the machine, then localization of a small plastic piece introduced into roasting pork (3 cm below the surface). At the end of the evaluation, the residents were asked to insert a 22 G needle into an exact predetermined target (i.e. point of fascia intersection). The progression of the needle was continuously controlled by ultrasound visualization using injection of a small volume of water (needle perpendicular to the longitudinal plane of the ultrasound beam). Two groups of two different examiners evaluated for each three trials the skill of the residents (quality, time to perform the machine adjustments, to localize the plastic target, and to hydrolocalize, and volume used for hydrolocalization). After each trial, residents evaluated their performance using a difficulty scale (0: easy to 10: difficult). RESULTS: All residents performed the adjustments from the last trial of each set, with a learning curve observed in terms of duration. Localization of the plastic piece was achieved by all residents at the 6th trial, with a shorter duration of localization. Hydrolocalization was achieved after the 4th trial by all subjects. Difficulty scale was correlated to the number of trials. All these results were independent of the experience of residents in regional anesthesia. DISCUSSION: Four trials were necessary to adjust correctly the machine, to localize a target, and to complete hydrolocalization. Ultrasonography in regional anesthesia seems to be a fast-learning technique, using this kind of practical training.

[Evaluation of synthetic glue for the fixation of continuous peripheral nerve catheters]. / Evaluation d'une colle liquide pour la fixation des cathéters périnerveux périphériques.

Accidental dislodgement of continuous peripheral nerve catheters remains a frequent problem that causes failure of postoperative analgesia. We have assessed the use of new synthetic glue (Mastisol) to secure and maintain catheters in the correct position among 60 patients. This method allowed securing an effective fixation in 94% of cases,resulting in efficient ambulatory orthopedic surgery postoperative analgesia. No nervous or infectious complications were observed. This technique offers a simple, complementary method to secure peripheral nerve catheters.

[Peripheral nerve block in orthopaedic surgery: multicentric evaluation of practicing professionals and impact on the activity of the recovery room]. / ALR périphérique en orthopédie: évaluation multicentrique des pratiques et impact sur l'activité de la SSPI.

OBJECTIVES: Since the last national survey on evaluation of professional practice in France, many peripheral nerve blocks techniques were developed. The aim of this study was to assess the place of such techniques and their impact on the stay in recovery room after orthopaedic surgery. STUDY DESIGN: Prospective, multicentric study. PATIENTS AND METHODS: Consecutive patients receiving a regional anaesthetic technique for orthopaedic surgery over a 15-day period were included in this multicenter study (four private clinics, two non-university and three university hospitals). Characteristics of blocks, duration of stay and activity of nurses in post-anaesthetic care unit (PACU) were recorded for each patient. RESULTS: A total of 289 blocks performed in 283 patients were analyzed. A regional anaesthetic technique was performed alone or associated with a light sedation (58 and 8% respectively) or with a general anaesthesia (44%). A continuous peripheral nerve block (mainly for femoral and iliofascial blocks) was performed in 25% of patients, mostly in university hospital and private clinics (35 and 26% respectively), but only in 3% of cases in non-university hospital. Mean duration of PACU stay was 64+/-67 minutes. This time was longer when regional anaesthesia was associated to or performed after general anaesthesia. Workload of nurses was a simple supervision in 47% of the cases (in 61% of patients receiving regional anaesthesia alone vs 21% in those with general anaesthesia, p<0.05). CONCLUSION: This survey confirms that peripheral nerve block became widely used in orthopaedic surgery. This decreases the medical workload in PACU, especially for distal upper limb surgery. Regional anaesthetic techniques must be well taught during formation cursus of residents.

[Ultrasound-guided infraclavicular block: a preliminary study of feasibility]. / Bloc infraclaviculaire sous contrôle échographique: une étude préliminaire de faisabilité.

OBJECTIVES: To assess the feasibility of neurostimulation and ultrasound guidance combination for infraclavicular brachial plexus block (ICB) technique. STUDY DESIGN: Prospective study. PATIENTS AND METHODS: Fifty consecutive patients scheduled for hand, forearm or elbow surgery were included. METHODS: A single stimulation lateral approach technique of ICB was performed. During the procedure, neurostimulation and ultrasound guidance were combined. The feasibility of ICB was assessed using a visual analogue scale (VAS, 0: impossible, 100: very simple) for ultrasound anatomical structures identification (VAS(Anat)) and for block placement (VAS (Block)). The success rate of ICB block was noted. RESULTS: No patient required general anaesthesia conversion. Median VAS+/-SD of VAS(Anat) and VAS(Block) were of 84+/-15 and 96+/-7, respectively. Success rate of ICB was 96%. No specific complication of ICB technique was noted. CONCLUSION: Combination of neurostimulation and ultrasound guidance is feasible. Combination of neurostimulation and ultrasound guidance secured ICB. Ultrasound-evidenced spread of local anaesthetics increased the success rate of ICB.

[Efficiency of secondary posterior trunk single stimulation, low volume infraclavicular plexus block for upper limb surgery]. / Bloc plexique infraclaviculaire en monostimulation: l'injection au contact du faisceau postérieur permet de réduire le volume d'anesthésique local.

OBJECTIVES: To assess the efficiency of a posterior secondary trunk single stimulation, low volume (30 ml 1.5% mepivacaine) infraclavicular brachial plexus block (ICB) technique. STUDY DESIGN: Prospective study. PATIENTS AND METHODS: One hundred consecutive patients scheduled for hand, forearm or elbow surgery were included. ICB was placed using a single stimulation technique. 30 ml 1.5% mepivacaine was injected when an evoked distal radial motor type response was elicited for 0.3-0.6 mA intensity current. Based upon both sensory and motor distribution ICB, characteristics and performance were assessed. RESULTS: No patient required general anesthesia conversion. Success rate was 92%. 8 patients required a total amount of 10 complementary distal troncular blocks. No specific complication of ICB technique was accoutered. All patients completed full neurological recovery from ICB 24 hours after surgery. CONCLUSION: 30 ml mepivacaine 1.5% ICB is suitable for upper limb surgery.