Pierre C. Nicole

Cricoid Pressure Does Not Increase the Rate of Failed Intubation by Direct Laryngoscopy in Adults

Background:Cricoid pressure (CP) is applied during induction of anesthesia to prevent regurgitation of gastric content and pulmonary aspiration. However, it has been suggested that CP makes tracheal intubation more difficult. This double-blind randomized study evaluated the effect of CP on orotracheal intubation by direct laryngoscopy in adults. Methods:Seven hundred adult patients undergoing general anesthesia for elective surgery were randomly assigned to have a standardized CP (n = 344) or a sham CP (n = 356) during laryngoscopy and intubation. After anesthesia induction and complete muscle relaxation, a 30-s period was allowed to complete intubation with a Macintosh No. 3 laryngoscope blade. The primary endpoint was the rate of failed intubation at 30 s. The secondary endpoints included the intubation time, the Cormack and Lehane grade of laryngoscopic view, and the Intubation Difficulty Scale score. Results:Groups were similar for demographic data and risk factors for difficult intubation. The rates of failed intubation at 30 s were comparable for the two groups: 15 of 344 (4.4%) and 13 of 356 (3.7%) in the CP and sham CP groups, respectively (P = 0.70). The grades of laryngoscopic view and the Intubation Difficulty Scale score were also comparable. Median intubation time was slightly longer in the CP group than in the sham CP group (11.3 and 10.4 s, respectively, P = 0.001). Conclusions:CP applied by trained personnel does not increase the rate of failed intubation. Hence CP should not be avoided for fear of increasing the difficulty of intubation when its use is indicated.

Complications associated with the Esophageal-Tracheal Combitube® in the pre-hospital setting

PurposeThe Esophageal-Tracheal Combitube® (Combitube) is widely used for the management of the airway during cardiopulmonary resuscitation in the pre-hospital setting. Although serious complications have been reported with the Combitube, there is a paucity of data relative to the frequency and nature of such complications. The objective of this retrospective study was to determine the incidence and the nature of complications associated to the Combitube in the pre-hospital setting.MethodsSince 1993, in the Quebec City Health Region, the basic life support treatment algorithm for emergency medical technicians has included the use of a Combitube as the primary airway device for management of all patients presenting with cardiac or respiratory arrest. The database of the emergency coordination services was searched for the period between 1993 and 2003 (2,981 patients). Only those patients who survived at least 12 hr were included. Medical records of these patients were reviewed to identify complications related to the use of the Combitube.ResultsTwo-hundred-eighty (280) patients were identified. Fifty-eight (58) patients (20.7%, confidence interval (CI)95% = 16.0%–25.4%) presented 69 complications: aspiration pneumonitis (n = 31), pulmonary aspiration (n = 16), pneumothorax (n = 6), upper airway bleeding (n = 4), esophageal laceration (n = 3),sc emphysema (n = 2), esophageal perforation and mediastinitis (n = 2), tongue edema (n = 2), vocal cord injury (n = 1), tracheal injury (n = 1), and pneumomediastinum (n = 1). Thirteen of these complications (12 patients, 4.3%, CI95% = 2.0%–6.3%) were judged as most likely resulting from trauma associated with insertion of the Combitube.ConclusionThe use of the Combitube in the pre-hospital setting is associated with a notable incidence of serious complications.RésuméObjectifLe Esophageal-Tracheal Combitube® (Combitube) est couramment utilisé pour assurer le contrôle des voies aériennes lors de situations d’arrêt cardio-respiratoire en préhospitalier. Bien que des complications graves reliées à l’utilisation du Combitube aient été rapportées, leur incidence réelle est mal connue. L’objectif de cette étude rétrospective était d’estimer l’incidence et la nature des complications associées à l’utilisation du Combitube en préhospitalier.MéthodeDepuis 1993, le protocole de prise en charge préhospitalière de l’Agence régionale de santé de Québec inclut l’insertion d’un Combitube par les techniciens ambulanciers pour le contrôle initial des voies aériennes des patients en arrêt cardiaque ou respiratoire. Une recherche dans le registre de la centrale de coordination des urgences a été faite et a permis d’identifier 2 981 patients pour la période de 1993 à 2003. Les patients ayant survécu au moins 12 h après leur arrivée à l’hôpital ont été inclut dans cette étude. Les dossiers médicaux de ces patients ont été étudiés afin d’identifier des complications associées à l’utilisation du Combitube.RésultatsDeux-cent-quatre-vingts (280) patients ont été inclut. Cinquante-huit (58) patients (20,7 %, intervalle de confiance (IC)95 % = 16,0-25,4 %) ont présenté 69 complications: pneumonie d’aspiration (n = 31), aspiration bronchique (n = 16), pneumothorax (n = 6), saignement des voies aériennes supérieures (n = 4), lacérations œsophagiennes (n = 3), emphysème sc (n = 2), perforation œsophagienne et médiastinite (n = 2), œdème de la langue (n = 2), lésion aux cordes vocales (n = 1), lésion trachéale (n = 1), pneumomédiastin (n = 1). Treize de ces complications (12 patients, 4,3 % 4,3 %, IC95% = 2,0 % - 6,3 %) ont été jugées le plus probablement associées à l’insertion du Combitube.

A Comparison of a Single or Triple Injection Technique for Ultrasound-guided Infraclavicular Block: A Prospective Randomized Controlled Study

BACKGROUND: Good success rates have been reported with ultrasound-guided infraclavicular block using one or multiple injections of local anesthetic. We hypothesized that a separate injection of local anesthetics on each cord enhances the onset of complete sensory block. We designed this prospective randomized study to compare the rate of complete sensory block using one or three injections of local anesthetic. METHODS: Patients scheduled for hand, wrist, or elbow surgery were included in this study. All blocks were performed under ultrasound guidance. In Group S (single injection), 30 mL of mepivacaine 1.5% was injected posterior to the axillary artery. In Group T (triple injections), 10 mL of mepivacaine 1.5% was injected on the posterior, medial, and lateral aspects of the axillary artery. Sensory block was evaluated every 3 min up to 30 min. The primary end point was the rate of complete sensory block at 15 min. RESULTS: Forty-nine and 51 patients were randomized in Groups S and T, respectively. The rate of complete sensory block was comparable at 15 min (Group S: 84%, Group T: 78%, P = 0.61) and at each time interval up to 30 min. There was no statistically significant difference in the rate of complications between the two groups. CONCLUSIONS: The success rate and the onset of complete sensory block after ultrasound-guided infraclavicular block are not enhanced by a triple injection of local anesthetic compared with a single injection posterior to the axillary artery.

Efficacy of a T-piece system and a continuous positive airway pressure system for apnea testing in the diagnosis of brain death

Objective:To prospectively compare three methods of apnea testing for the confirmation of brain death. Design:Prospective, randomized, crossover study. Setting:Intensive care unit of a tertiary care university hospital. Patients:Twenty adult patients requiring apnea testing for confirmation of brain death. Interventions:Ten minute apnea testing was repeated in random order for every patient with the three oxygenation systems: oxygen catheter inserted through the endotracheal tube (oxygen 6 L/min), T-piece system (oxygen 12 L/min), and continuous positive airway pressure (CPAP) system 10 cm H2O (oxygen 12 L/min). Measurements and Main Results:Arterial blood was drawn at 0, 2, 5, and 10 mins of each test. Compared with baseline, Paco2 increased by 30.6 ± 7.4, 30.0 ± 7.3 and 30.2 ± 7.5 mm Hg during the apnea period (p = .96), reaching 73.3 ± 8.3, 71.6 ± 11.1, and 72.7 ± 9.0 mm Hg at the end of the apnea test (p = .73) for the oxygen catheter, the T-piece, and the CPAP, respectively. Pao2 decreased less with the CPAP compared with the oxygen catheter or the T-piece (−22.4 ± 76, −99.1 ± 158, and −91.6 ± 133 mm Hg, respectively, p < .01). In two patients, apnea testing could not be completed with the oxygen catheter and the T-piece because of desaturation, although it could be completed with the CPAP. Conclusions:The T-piece and the CPAP systems are effective alternatives to the standard oxygen catheter technique for apnea testing. Oxygenation was best maintained with the CPAP system, which can be useful in some patients.

Comparison of a single- or double-injection technique for ultrasound-guided supraclavicular block: a prospective, randomized, blinded controlled study.

Background Despite good success rates reported with ultrasound-guided supraclavicular block using 1 or multiple injections, no consensus exists on the best technique to use. We designed this study to test the hypothesis that a double-injection technique would hasten the onset of sensory block. Methods Adult patients undergoing hand, wrist, or elbow surgery were enrolled in this prospective double-blind randomized study. Blocks were performed under ultrasound guidance. In group S (single injection), 30 mL of mepivacaine 1.5% was injected at the junction of the subclavian artery and the first rib. In group D (double injection), 15 mL of the same solution was injected at the site described above, then 15 mL was injected in the most superficial portion of the lateral aspect of the cluster formed by the brachial plexus trunks and divisions. The primary end point was the rate of complete sensory block at 15 mins. Secondary end points were the rates of sensory, motor, and surgical blocks and procedure time. Results Fifty-one patients were randomized to each group. The rate of complete sensory block was similar at 15 mins (group S: 49% [95% confidence interval, 36%–62%], group D: 53% [95% confidence interval, 40%–66%]; P = 0.80) and at each time interval. The rates of complete motor block and surgical block success were similar between groups. The procedure time was shorter in group S (179 ± 104 vs 275 ± 137 secs; P < 0.01). Conclusions The double-injection technique offers no benefit over a single injection for the performance of an ultrasound-guided supraclavicular block.

A Comparison of an Injection Cephalad or Caudad to the Division of the Sciatic Nerve for Ultrasound-Guided Popliteal Block: A Prospective Randomized Study

BACKGROUND The optimal site for local anesthetic injection during ultrasound-guided sciatic popliteal block remains controversial. METHODS Patients were randomized to receive 25 mL ropivacaine 0.75% around the sciatic nerve cephalad to the peroneal-tibial division in group A (n = 51) or caudad to the division in group B (n = 51). The sensory and motor blocks were evaluated every 5 minutes up to 30 minutes. RESULTS Rates of complete sensory block and surgical anesthesia were superior in group B (P < 0.0001). CONCLUSION The caudad technique provided better surgical anesthesia.

Stability of norepinephrine infusions prepared in dextrose and normal saline solutions

Purpose: Norepinephrine (NE) infusions are commonly used in the intensive care unit and in the operating room. Data on long term stability of NE solutions are lacking. This prospective study was designed to evaluate the stability of NE, in dextrose (5%) in water (D5W) and in normal saline (NS) solutions, for a period up to seven days.Methods: We prepared norepinephrine solutions in quadruplicate, by aseptically diluting 1 mg NE in 250 mL of D5W or NS and 4 mg NE in 250 mL of D5W or NS (final concentrations, 4µg·mL−1 and 16µg·mL−1, respectively) and stored the solutions at room temperature under ambient light. We sampled the solutions, in duplicate, at times 0, 24, 48, 72, 120, and 168 hr and stored them at −80°C for later assay. Norepinephrine concentrations were measured by high-performance liquid chromatography with electrochemical detection (coefficient of variation 4.6%). Statistical analysis was done by nonparametric, repeated measures ANOVA (Friedman test).Results: There was no significant decrease in NE concentration for either, NE 4µg·mL−1 in D5W or NS (P=0.09 and 0.11, respectively) or for NE 16µg·mL−1 in D5W or NS (P=0.18 and 0.40, respectively). The ratios of NE concentration at 168 hr, compared to baseline, were 95.7% and 96.4%, for NE 4µg·mL−1 in D5W and NS, respectively, and 104.5% and 96.4%, for NE 16µg·mL−1 in D5W and NS, respectively.Conclusion: Norepinephrine solutions, in concentrations commonly used in the clinical setting, are chemically stable for seven days, at room temperature and under ambient light, when diluted either in D5W or NS.RésuméObjectif: Les perfusions de norépinéphrine (NE) sont fréquemment utilisées aux soins intensifs et en salle d’opération. Toutefois, les données concernant la stabilité à long terme des solutions de NE font défaut. Cette étude prospective a été conçue dans le but d’évaluer la stabilité de la NE préparée dans des solutions de dextrose (5 %) dans l’eau (D5W) et de chlorure de sodium 0,9 % (NS), pendant une durée maximale de sept jours.Méthode: Nous avons préparé des solutions de norépinéphrine en quatre exemplaires en diluant en milieu stérile 1 mg de NE dans 250 mL de D5W ou de NS et 4 mg de NE dans 250 mL de D5W ou de NS (concentrations finales de NE de 4 µg·mL−1 et de 16 µg·mL−1, respectivement). Nous avons stocké ces solutions à température et lumière ambiantes. Nous avons échantillonné les solutions en deux exemplaires à 0, 24, 48, 72, 120 et 168 h et les avons stockées à une température de −80°C pour fin d’analyses ultérieures. Les concentrations de norépinéphrine ont été mesurées par chromatographie liquide à haute performance avec une détection électrochimique (coefficient de variation 4,6 %). L’analyse statistique a été effectuée en utilisant une ANOVA (test de Friedman) pour mesures non paramétriques répétées.Résultats: Il n’y a eu de réduction significative dans la concentration de NE dans aucune des solutions, que ce soit NE 4 µg·mL−1 dans une solution de D5W ou de NS (P=0,09 et 0,11, respectivement) ou pour la solution de NE à 16 µg·mL−1 dans du D5W ou du NS (P=0,18 et 0,40, respectivement). Les ratios de concentration de norépinéphrine à 168 h, comparées aux données initiales, étaient de 95,7 % et 96,4 % pour la NE 4 µg·mL−1 dans les solutions de D5W et de NS, respectivement, et de 104,5 % et 96,4 % pour la NE 16 µg·mL−1 dans les solutions de D5W et de NS, respectivement.Conclusion: Les solutions de norépinéphrine, aux concentrations fréquemment utilisées dans un contexte clinique, sont chimiquement stables pour sept jours si elles sont conservées à température et lumière ambiantes, qu’elles soient diluées dans des solutions de D5W ou de NS.

Postoperative complications in patients with oculopharyngeal muscular dystrophy: A retrospective study

PurposeOculopharyngeal muscular dystrophy (OPMD) is a genetic disease with autosomal dominant transmission particularly common in Quebec where its prevalence is about 1: 1000. The main features are bilateral ptosis of the eyelids and dysphagia. These symptoms are frequently treated surgically by levator palpebrae resection (LPR) and cricopharyngeal myotomy (CPM). The objectives of this retrospective chart review were to describe the postoperative complications in OPMD patients undergoing LPR or CPM and to determine their incidence.MethodsMedical records of all OPMD patients who had either LPR or CPM between 1997 and 2002 were reviewed. The following complications were collected: death, pneumonia, aspiration pneumonitis, airway obstruction, reintubation, and severe coughing and choking caused by profuse secretions.ResultsOne hundred and fourteen surgeries on 92 OPMD patients were studied. Fifty-nine were LPR under general anesthesia (LPR-GA) and 22 were LPR under local anesthesia (LPR-LA). Thirty-three surgeries were CPM, all under general anesthesia. There was no death or reintubation. Patients who had LPR-LA had shorter postanesthesia care unit (P < 0.001) and ambulatory surgery unit (P < 0.001) stays than those who had LPR-GA. Complications were more frequent after CPM than LPR-GA (P< 0.001).ConclusionThe complication rate after LPR was low. Both local and general anesthesia are safe alternatives in OPMD patients operated for LPR. Patients having CPM presented more respiratory complications than those having LPR.RésuméObjectifLa dystrophie musculaire oculo-pharyngée (OPMD) est une maladie génétique à transmission autosomale dominante dont la prévalence au Québec est de 1:1000. Ses symptômes cardinaux, la ptose palpébrale et la dysphagie, sont traités par une résection des muscles releveurs des paupières (LPR) et par une myotomie crico-pharyngée (CPM). Les objectifs de cette étude rétrospective étaient de décrire les complications postopératoires des patients atteints de OPMD subissant une LPR ou une CPM et de déterminer leur incidence.MéthodeLes dossiers médicaux de tous les patients atteints de OPMD et ayant subi une LPR ou une CPM entre 1997 et 2002 ont été révisés. Les complications recherchées ont été: décès, pneumonie, pneumonie d’aspiration, obstruction respiratoire, réintubation et toux sévère avec étouffement causés par des sécrétions abondantes.RésultatsCent quatorze chirurgies effectuées chez 92 patients avec OPMD ont été étudiées. Cinquante-neuf étaient des LPR sous anesthésie générale (LPR-GA), 22 des LPR sous anesthésie locale (LPR-LA) et 33 des CPM sous anesthésie générale. Il n’y a eu aucun décès ni réintubation. Les patients ayant subi une LPR-LA ont eu un séjour à la salle de réveil et à l’unité de chirurgie ambulatoire d’une durée inférieure à ceux ayant subi une LPR-GA (P < 0,001). Les complications ont été plus fréquentes suite aux CPM comparativement aux LPR-GA (P < 0,001).ConclusionLa LPR est associée à un faible taux de complications et peut être faite de façon sécuritaire sous anesthésie locale ou générale. La CPM présente plus de complications respiratoires que la LPR.

Nausea and vomiting after laparoscopic surgery are not associated with an increased peripheral release of serotonin

PurposeTo determine whether patients suffering postoperative nausea and vomiting (PONV) present a different serotonin release pattern from those who do not present this complication.MethodsForty-eight consecutive women undergoing outpatient laparoscopic tubal ligation were enrolled in this prospective, cumulative case-control study. The study compared serotonin activity in 15 patients totally free of emetic symptoms (asymptomatic group) and, among patients with PONV (n = 33), those 15 who presented the most severe symptoms (PONV group). Patients were anesthetized with a regimen including sufentanil (0.1–0.3 μg·kg−1) plus thiopental (3–5 mg·kg−1) for induction and isoflurane (0.6–1%) in nitrous oxide (60%) for maintenance. Peripheral serotonin activity was assessed by measurement with high-performance liquid chromatography of serotonin’s principal urinary metabolite: 5-hydroxyindoacetic acid (5-HIAA) corrected for urinary creatinine.ResultsThe preoperative and postoperative urinary 5-HIAA: creatinine ratios were 6.9 ng·μg−1 (confidence interval; CI 95%, 2.7–11.0) and 5.9 ng·μg−1 (CI 95%, 2.4–9.4) respectively in the asymptomatic group (P = 0.69), and were 5.1 ng·μg−1 (CI 95%, 2.5–7.7) and 5.6 ng·μg−1 (CI 95%, 3.4–7.7) respectively in the PONV group (P = 0.75). There was also no difference between groups in the variation of 5-HIAA: creatinine ratios from the preoperative to the postoperative period (P = 0.21).ConclusionPONV after laparoscopic tubal ligation are not associated with an increased urinary excretion of serotonin metabolites. Patients with severe PONV present a peripheral serotonin release comparable to asymptomatic patients.RésuméObjectifDéterminer si les patientes souffrant de nausées et vomissements postopératoires (NVPO) ont un profil de sécrétion de la sérotonine différent de celles qui ne présentent pas cette complication.MéthodeQuarante-huit femmes qui se sont présentées successivement en chirurgie ambulatoire pour une ligature tubaire par laparoscopie ont participé à cette étude prospective cas-témoins. Le profil de sécrétion de la sérotonine chez 15 patientes qui ne présentaient aucun symptôme émétique (groupe asymptomatique) a été, comparé à celui des 15 patientes ayant présenté les symptômes les plus sévères (groupe NVPO). L’anesthésie a été induite avec du sufentanil (0,1 –0,3 μg·kg−1) et du thiopental (3–5 mg·kg−1) et maintenue avec de l’isofurane (à 0,6 –1 %) dans du protoxyde d’azote (à 60 %). L’activité périphérique de la sérotonine a été évaluée par la mesure du principal métabolite urinaire de la sérotonine au moyen de la Chromatographie liquide haute performance: l’acide 5-hydroxy-indole acétique (5-HIAA) corrigé pour la créatinine urinaire.RésultatsLes ratios 5-HIAA urinaire préopératoire et postopératoire: créatinine ont été de 6,9 ng·μg−1 (intervalle de confiance IC de 95 %, 2,7–11,0) et de 5,9 ng·μg−1 (IC 95 %, 2,4–9,4) respectivement chez tes patientes asymptomatiques (P = 0, 69), et de 5,1 ng·μg−1 (IC 95 %, 2,5–7,7) et 5,6 ng·μg−1 (IC 95 %, 3,4–7,7) respectivement pour tes patientes du groupe NVPO (P = 0,75). Il n’y a pas eu de différence intergroupe pour la variation des ratios 5-HIAA:créatinine entre les périodes préopératoire et postopératoire (P = 0,21).ConclusionLes NVPO suivant la ligature des trompes laparoscopique ne sont pas associés à une sécrétion urinaire accrue des métabolites de la sérotonine. La sécrétion périphérique de sérotonine est comparable pour les patientes qui souffrent de NVPO sévères et les patientes asymptomatiques.

Ultrasound-Guided Single-Injection Infraclavicular Block Versus Ultrasound-Guided Double-Injection Axillary Block: A Noninferiority Randomized Controlled Trial.

BACKGROUND:Single-injection ultrasound-guided infraclavicular block is a simple, reliable, and effective technique. A simplified double-injection ultrasound-guided axillary block technique with a high success rate recently has been described. It has the advantage of being performed in a superficial and compressible location, with a potentially improved safety profile. However, its effectiveness in comparison with single-injection infraclavicular block has not been established. We hypothesized that the double-injection ultrasound-guided axillary block would show rates of complete sensory block at 30 minutes noninferior to the single-injection ultrasound-guided infraclavicular block. METHODS:After approval by our research ethics committee and written informed consent, adults undergoing distal upper arm surgery were randomized to either group I, ultrasound-guided single-injection infraclavicular block, or group A, ultrasound-guided double-injection axillary block. In group I, 30 mL of 1.5% mepivacaine was injected posterior to the axillary artery. In group A, 25 mL of 1.5% mepivacaine was injected posteromedial to the axillary artery, after which 5 mL was injected around the musculocutaneous nerve. Primary outcome was the rate of complete sensory block at 30 minutes. Secondary outcomes were the onset of sensory and motor blocks, surgical success rates, performance times, and incidence of complications. All outcomes were assessed by a blinded investigator. The noninferiority of the double-injection ultrasound-guided axillary block was considered if the limits of the 90% confidence intervals (CIs) were within a 10% margin of the rate of complete sensory block of the infraclavicular block. RESULTS:At 30 minutes, the rate of complete sensory block was 79% in group A (90% CI, 71%–85%) compared with 91% in group I (90% CI, 85%–95%); the upper limit of CI of group A is thus included in the established noninferiority margin of 10%. The rate of complete sensory block was lower in group A (proportion difference of 12% [95% CI, 2–22]; P = 0.0091), as was surgical success rate (82% [95% CI, 74%–89%] vs 93% [95% CI, 86%–97%]; proportion difference of 11% [95% CI 1–20]; P = 0.0153). Sensory block onset also was slower in group A (log rank test P = 0.0020). Performance times were faster in group I (231 seconds [95% CI, 213–250]) than in group A (358 seconds [95% CI, 332–387]; P < 0.0001). No statistically significant difference was observed for vascular puncture, paresthesia during block performance, or procedure-related pain. No neurologic complication was noted at follow-up. CONCLUSIONS:We failed to demonstrate that the rate of complete sensory block of the double-injection axillary block is noninferior to the single-injection infraclavicular block. However, the rate of complete sensory block at 30 minutes is statistically significantly lower with the axillary block. The ultrasound-guided single-injection infraclavicular block thus seems to be the preferred technique over the axillary for upper arm anesthesia.