La laringoscopia indirecta mediante endoscopio rígido de 70º como valor predictivo de la dificultad de visión de la laringe / Indirect laryngoscopy with rigid 70-degree laryngoscope as a predictor of difficult direct laryngoscopy

Introducción y objetivos: Los predictores comúnmente utilizados para prever la vía aérea difícil poseen poca capacidad para pronosticarla. Nuestro objetivo es investigar la potencia de la laringoscopia indirecta con el laringoscopio rígido de 70° como predictor de dificultad de visión de la laringe con la laringoscopia directa. Métodos: Se efectuó una laringoscopia indirecta con el laringoscopio rígido en el preoperatorio a 300 pacientes. Según la visión obtenida fueron clasificados en 4 grados: 1 (cuerdas vocales visibles), 2 (comisura posterior visible), 3 (visión solo de epiglotis) y 4 (ninguna estructura glótica visible). EL 3 y el 4 eran considerados predictores de dificultad de visión de la laringe. Después, bajo anestesia general, practicamos a los pacientes la laringoscopia directa con el laringoscopio de Macintosh. Valoramos como positivo el encontrar un Cormack-Lehane III-IV. Se registraron otros predictores clínicos comunes. Se elaboró un modelo de regresión logística con fines predictivos utilizando las variables relevantes. Investigamos también los predictores de la dificultad de visión de la laringe con la laringoscopia indirecta. Resultados: El modelo encontrado y sus coeficientes para confeccionarlo fueron: f(x)=-10,097+5,145 laringoscopia indirecta (3-4)+3,489 retrognatia +2,548 apertura boca <3,5cm+1,911 distancia tiromentoniana <6,5cm+1,352 roncopatía+ (0,151*cm grosor cuello). Proporciona un resultado correcto en el 94,3% de los casos. En el caso de la laringoscopia indirecta el modelo hallado era: f(x)=-2,641+0,920 roncopatía+0,875 movilidad cervical. Conclusiones: La laringoscopia indirecta fue la variable independiente con más poder predictivo (mayor coeficiente). La roncopatía es un predictor común entre los modelos de ambas laringoscopias(AU)

Introduction and objectives: The commonly-used predictors for difficult airway management are not very accurate. We investigate the power of indirect laryngoscopy with the rigid 70-degree laryngoscope as a predictor of difficult visualisation of the larynx with direct laryngoscopy. Methods: We performed preoperative indirect laryngoscopy with the rigid laryngoscope on 300 patients. The vision obtained was classified into four grades: 1 (vocal cords visible), 2 (posterior commissure visible), 3 (epiglottis visible) and 4 (no glottic structure visible). Grades 3 and 4 were considered predictors of difficult larynx visualisation. Next, direct laryngoscopy with the Macintosh laryngoscope was carried out on the patients under general anaesthesia. Positive value was defined as a Cormack and Lehane III and IV. Other common clinical predictors were also analysed. A logistic regression model using the relevant variables was elaborated. We also investigated predictors of difficult visualisation of the larynx with indirect laryngoscopy. Results: The model found and the coefficients for preparing it were: f(x)= -10.097+5.145 indirect laryngoscopy (3-4)+3.489 retrognathia +2.548 mouth opening <3.5cm +1.911 thyromental distance <6.5cm +1.352 snorer+(0.151 * cm neck thickness). This model provided a correct result in 94.3% of cases. In the case of indirect laryngoscopy, the model found was: f (x)=-2.641+0.920 snorer+0.875 cervical mobility. Conclusions: Indirect laryngoscopy was the independent variable with the greatest predictive power. Snoring is a common predictor in both laryngoscopy models(AU)

Interaction of cerebrovascular disease and contralateral carotid occlusion in prediction of shunt insertion during carotid endarterectomy.

INTRODUCTION: To assess the possible role and the interaction of cerebrovascular disease and vascular stenosis on the necessity of shunt insertion during carotid endarterectomy (CEA). MATERIAL AND METHODS: Eighty consecutive patients undergoing CEA under regional anaesthesia were prospectively enrolled. Patients were divided into two groups depending on whether they were shunted or not. The measured end-points were co-morbidities degree of contralateral and carotid stenosis and other intra- and postoperative outstanding parameters. ANOVA, Student's t and χ(2) tests were used (p<0.05). Variables differing significantly between groups and potential confounders were used in backward stepwise logistic regression to estimate the relative risk (RR, 95% CI) of shunt. In addition Wald's test (p<0.05) with and without adjustments for potential confounders was used with various different multivariate analysis models. RESULTS: Contralateral stenosis and cerebral vascular accidents (CVA) were more frequently observed in shunted patients. The RR for patients with contralateral stenosis ≥ 50% was 1.3 (95% CI 1.0-1.5) and for patients with previous CVA was 1.2 (95% CI 1.0-1.4). For contralateral stenosis and CVA together the RR increased to 7.7 (95% CI 1.0-14.4). A model based on contralateral stenosis and CVA was found to be statistically significant (p=0.003) for shunt (RR=1.1, 95% CI 1.0-2.1). Relative excess risk due to interaction of both factors was 6.2. CONCLUSIONS: The findings suggest that patients with contralateral stenosis ≥ 50% and previous CVA have a higher risk of requiring shunt use during CEA than patients with these risk factors separately.

Indirect laryngoscopy with rigid 70-degree laryngoscope as a predictor of difficult direct laryngoscopy.

INTRODUCTION AND OBJECTIVES: The commonly-used predictors for difficult airway management are not very accurate. We investigate the power of indirect laryngoscopy with the rigid 70-degree laryngoscope as a predictor of difficult visualisation of the larynx with direct laryngoscopy. METHODS: We performed preoperative indirect laryngoscopy with the rigid laryngoscope on 300 patients. The vision obtained was classified into four grades: 1 (vocal cords visible), 2 (posterior commissure visible), 3 (epiglottis visible) and 4 (no glottic structure visible). Grades 3 and 4 were considered predictors of difficult larynx visualisation. Next, direct laryngoscopy with the Macintosh laryngoscope was carried out on the patients under general anaesthesia. Positive value was defined as a Cormack and Lehane III and IV. Other common clinical predictors were also analysed. A logistic regression model using the relevant variables was elaborated. We also investigated predictors of difficult visualisation of the larynx with indirect laryngoscopy. RESULTS: The model found and the coefficients for preparing it were: f(x)= -10.097+5.145 indirect laryngoscopy (3-4)+3.489 retrognathia+2.548 mouth opening <3.5 cm+1.911 thyromental distance <6.5 cm+.352 snorer+(0.151 cm neck thickness). This model provided a correct result in 94.3% of cases. In the case of indirect laryngoscopy, the model found was: f(x)=-2.641+0.920 snorer+0.875 cervical mobility. CONCLUSIONS: Indirect laryngoscopy was the independent variable with the greatest predictive power. Snoring is a common predictor in both laryngoscopy models.

Bispectral index variations in patients with neurological deficits during awake carotid endarterectomy.

BACKGROUND AND OBJECTIVE: The bispectral index (BIS) is derived from the EEG and therefore may be useful to diagnose intraoperative cerebral ischaemia. This study was undertaken to investigate BIS changes in awake patients with and without neurological deficits during carotid endarterectomy under regional anaesthesia. METHODS: Seventy consecutive carotid endarterectomies under regional anaesthesia were divided into two surgical groups: patients with and patients without neurological deficits. Patients' neurological status was evaluated and neurological deficits were compared with BIS values. Measurements were made at different surgical stages: baseline, after sedation, at the beginning of surgery, at preclamping, at the 3 min clamping test, during shunt insertion, at declamping, 15 min after declamping and at the end of surgery. We performed intergroup and intragroup comparisons of BIS values. A decrease in BIS of at least 10 associated with neurological deficits was taken as the cut-off point for the classification of patients with logistic regression models (crude and adjusted for potential confounders). RESULTS: Thirteen patients (18.6% of the total) developed clinical cerebral ischaemia, though BIS values decreased in 10 of these patients (76.9%). The mean BIS values were 92.5+/-5.6 and 84.7+/-12.3 for patients without and with neurological deficits, respectively (P value<0.05). The odds ratios of a BIS decrease associated with neurological deficits were 8.5 (95% confidence interval 2.1-35.1) and 5.4 (95% confidence interval 1.2-24.3) adjusted for contralateral stenosis. CONCLUSION: Our results describe a relationship between BIS reductions and neurological deficits during carotid surgery in awake patients.