Search

Oxygenation maintenance is the cornerstone of airway management in the obese patient related to anatomic and pathophysiologic issues. Difficult mask ventilation (DMV) risk is increased in obese patients according recognized predictors (Body Mass Index [BMI]26 kg/m2, age55 years, jaw protrusion severely limited, lack of teeth, snoring, beard, Mallampati class III or IV) and should systematically search. Difficult tracheal intubation (DTI) risk may be increased and risk should be assessed in a careful manner. Increased neck circumference and high BMI (35 kg/m2) should be added to "standard" preoperative airway assessment including:Mallampati class, mouth opening and thyromental distance. In obese patients, preoxygenation is mandatory by 25° head-up position achieving better gas exchange than in supine position. In addition, to prevent early arterial oxygen desaturation related to a reduced functional residual capacity (FRC), atelectasis formation during anesthetic induction and after tracheal intubation, non invasive positive pressure ventilation and application of PEEP throughout this period are recommended. Airway management in obese patients has to consider: the anesthesia technique with maintenance or not of spontaneous ventilation, the available oxygenation technique in case of anticipated DMV, and the appropriate tracheal intubation technique (fiberoptic intubation technique or videolaryngoscope) according to the patient status and will. In unexpected difficult airway, the very first priority is oxygenation and a predefined strategy has to be implemented with oxygenation devices first (supraglottic devices or ILMA). Lastly, the final step of the obese airway management is tracheal extubation and recovery. A strategy with a fully awake patient, without residual paralysis, and a 25° head-up position is mandatory.

Abnormalities of skeletal muscles are frequently observed in patients with congestive heart failure. In these patients, angiotensin-converting enzyme (ACE) inhibitors improve exercise performance. The present study was designed to assess whether skeletal muscle dysfunction develops in the early stage of cardiac overload and if so, whether such functional alterations can be prevented by ACE inhibition. Mechanical performance, cross-bridge (CB) properties, and myosin heavy chain composition were investigated in respiratory and limb skeletal muscles of rabbits with moderate cardiac hypertrophy, and after single therapy with the ACE inhibitor perindopril (PE). After constriction of the aorta, the rabbits were treated during a 10-week period with either PE (1 mg/kg/day; n = 9) or a placebo (PL; n = 15). A third group of sham-operated animals received PL (n = 10). Analyses were performed on isolated diaphragm and soleus strips. Compared with sham-operated animals (shams), peak tetanic tension in PL fell by 40% in diaphragm and 34% in soleus. There were no significant differences in peak tetanic tension and the maximum shortening velocity between PE and shams. In both muscles, the total number of CBs was significantly lower in PL than in shams, but did not differ between shams and PE. The elementary force per CB did not differ between groups. In both muscles, the myosin heavy chain composition did not differ between groups. The study demonstrated that intrinsic performance of diaphragm and soleus muscles was affected early in the development of chronic pressure overload. Single therapy with PE tended to preserve muscle strength, essentially by limiting the loss of CBs.

We organized a training program for oral fiber optic intubation (FOI) under conscious sedation. The efficacy of the program was evaluated by comparing the performances of experts and novices.The training procedure was divided into two sessions: a theoretical session on difficult airways, the fiber optic bronchoscope (FOB), remifentanil, topical anesthesia and patient interactions; and a session involving simulations of the FOI technique on dummies. For in vivo FOI, we enrolled patients requiring orotracheal intubation for elective surgery. Electrocardiograms, mean arterial pressure was railroaded over the fiberscope, and tracheal intubati6 and 7) FOIs, respectively, joined the study. To reach ±23 bpm, P=0.02), and RR was decreased (from 16±3 to 12±4 bpm, P0.05). No differences were recorded between the experts and less-experienced anesthesiologists. The average duration of FOI was 3.3±2.0 min for experts and 4.2±2.4 min for novices (P=0.03). Procedures were successful in both groups, with patients in each group being equally satisfied with the procedures.This study highlights the importance of a structured FOI training program, demonstrating that it is possible to learn to perform FOI proficiently by practicing on dummies.

The aim of the pilot study was to assess by ultrasound changes in dimensions of lung consolidation and reaeration after drainage of large pleural effusion in patients with acute respiratory distress syndrome (ARDS).Lung ultrasound and blood gas were performed before, 2 hours (H2) and 24 hours (H24) after drainage of pleural effusion. Lung ultrasound aeration score was calculated. Cephalocaudal dimension and diaphragmatic transversal area of lung consolidation were measured.Ten patients were studied. Median volume of drained effusion was 675 ml at H2 and 895 at H24. Two hours after drainage, dimension of cephalocaudal consolidation and diaphragmatic transversal area decreased significantly. Lung reaeration after drainage occurred mainly in latero-inferior and postero-superior regions. PaO2/FiO2 increased significantly at H24.Ultrasound is a useful method to assess lung consolidation after pleural effusion drainage. Drainage of pleural effusion may lead to a decrease of lung consolidation and improvement of lung reaeration.