[Relationship between laryngoscopy degree and intubation difficulty]. / Relación entre el grado de largingoscopia y de dificultad de intubación.

OBJECTIVES: To determine the relation between difficult intubation and grade of direct laryngoscopy, as well as the factors that influence them, and prognosis. PATIENTS AND METHOD: In 1,336 patients receiving general anesthesia, seven airway measurements were made to reflect degree of difficulty and predictive value of presurgical tests on direct laryngoscopy and intubation. RESULTS: The incidences of difficult laryngoscopic and intubation procedures were 1.4 and 3.0%, respectively. Difficult intubation was more frequent in women and in patients between 40 and 65 years of age (p < 0.05). In 105 intubations (64.8%) performed with moderate difficulty (use of a stylette, external laryngeal pressure or two tries) and 17 (41.5%) performed with difficulty (three or more tries), the laryngoscopic procedure was graded as easy (Cormack-Lehane grade I-II). In these cases (easy laryngoscopy with moderate/difficult intubation), the causes recorded were size of endotracheal tube in comparison with the laryngeal opening (n = 11); anterior glotis (n = 36); insufficient relaxation (n = 31); disease in or beyond the vocal cords (n = 29); or undetermined (n = 15). In the easy intubation cases, the laryngoscopic procedures were grade III in 2.9%. Intubation was difficult in 16.3% (n = 39) of patients presenting some type of abnormality upon examination of the airway (p < 0.05). The airway characteristic that best predicted laryngoscopic difficulty was extension of the lower neck to 90 degrees (relative risk of 4.46), mouth opening less than 3.5 cm (3.92), presence of two airway abnormalities (4.25) and presence of three or more abnormalities (5.39) (p < 0.01). CONCLUSION: The fact that cases of easy laryngoscopy coincide with difficult intubation suggests that, to the degree of intubation difficulty must be added extrinsic factors (individual skill, maneuvers performed, instrumentation, relaxation of the laryngeal musculature and others) that are hard to standardize and reflect when predicting an intubation by the grade of difficulty in laryngoscopy.

[Brachial plexus anesthesia: results of a modified perivascular supraclavicular technique]. / Anestesia del plexo braquial: resultados de una técnica supraclavicular perivascular modificada.

OBJECTIVES: To compare a modified supraclavicular perivascular approach with the axillary perivascular technique for providing brachial plexus blockade. PATIENTS AND METHODS: We studied 100 ASA I/II patients undergoing surgery on upper extremities. Patients were divided into two groups: group 1 (axillary, n = 50) and group 2 (modified supraclavicular, n = 50 ). Patients needing shoulder surgery were excluded from group 1. In both groups 35 ml of 1.5% mepivacaine plus 0.05 mEq/ml of bicarbonate was used. The Winnie axillary perivascular technique was used in group 1. In group 2 we used a modification of the lateral perivascular supraclavicular technique described by Brown, with the needle directed cephalad, medial and posterior to provide paresis in the upper extremity. We recorded the degree of difficulty and time needed for each technique, time until start of paresis and time of motor paralysis in the extremity, area of nerve deficit, and quality of block. In group 2 we measured the depth of paresthesia. Perioperative complications were noted for each group. RESULTS: There were no significant differences in difficulty, time or quality of block. Time until start of paresis and time of motor paralysis were significantly shorter in group 2 (12.0 +/- 2.5 versus 4.9 +/- 0.2 min, and 15.2 +/- 6.9 min versus 35.3 +/- 5.2, in groups 2 and 1, respectively). Mean depth of paresthesia was 44.1 +/- 5.2 min. The most frequently recorded complications were Horner's syndrome in group 2 and vascular puncture in group 1. CONCLUSIONS: The modified perivascular lateral supraclavicular technique is a safe, effective method for providing brachial plexus block.