ABSTRACT
Abstract Background and objectives: The prediction of difficult laryngoscopy is based on tests that assess anatomic characteristics of face and neck. We aimed to identify the most accurate tests and propose a multivariate predictive model. Methods: This prospective observational study included 1134 patients. Thyromental Distance (TMD), Sternomental Distance (STMD), Ratio of Height-to-Thyromental Distance (R-H/TMD), Neck Circumference (NC), Ratio of Neck Circumference-to-Thyromental Distance (R-NC/TMD), Hyomental Distance with head in Neutral Position (HMD-NP) and at Maximal Extension (HMD-HE), Ratio of Hyomental Distance at Maximal head extension-to-hyomental distance in neutral position (R-HMD), Mallampati Class (MLC), Upper Lip Bite Test (ULBT), Mouth Opening (MO) and Head Extension (HE) were assessed preoperatively. A Cormack-Lehane Grade ≥ 3 was defined as Difficult Laryngoscopy. Sensitivity, specificity, positive and negative predictive values were assessed for all tests. Multivariate analysis with logistic regression was used to create the predictive models. Results: A model incorporating MLC, ULBT, HE, HMD-HE and R-NC/TMD showed high prognostic accuracy; x2(5) = 109.12, p < 0.001, AUC = 0.86, p < 0.001). Its sensitivity, specificity and negative predictive value were 82.3%, 74.8% and 97.4%, respectively. A second model including two measurements not requiring patient's cooperation (R-NC/TMD and HMD-HE) exhibited good prognostic performance; x2(2) = 63.5, p < 0.001, AUC = 0.77, p < 0.001. Among single tests, HE had the highest sensitivity (78.5%) and negative predictive value (96%). Conclusions: A five-variable model incorporating MLC, ULBT, HE, HMD-HE and R-NC/TMD showed satisfyingly high predictive value for difficult laryngoscopy. A model including R-NC/TMD and HMD-HE could be useful in incapable patients. The most accurate single predictor was HE.
Resumo Justificativa e objetivos: A previsão de laringoscopia difícil se baseia em testes que avaliam as características anatômicas da face e pescoço. Nosso objetivo foi identificar os testes mais precisos e propor modelo preditivo multivariado. Método: Estudo observacional prospectivo incluiu 1134 pacientes e avaliou no pré-operatório: Distância Tireomentoniana (DTM), Distância Esternomentoniana (DEM), razão Altura-Distância Tireomentoniana (A/DTM), Circunferência Cervical (CC), razão Circunferência Cervical-Distância Tireomentoniana (CC/DTM), Distância Hiomentoniana com a cabeça na Posição Neutra (DHM-PN) e em Extensão Máxima (DHM-EM), razão Distância Hiomentoniana com Cabeça em Extensão Máxima/Distância Hiomentoniana na posição Neutra (DHME/DHMN), Classe Mallampati (CML), Teste da Mordida do Lábio Superior (TMLS), Abertura da Boca (AB) e Extensão da Cabeça (EC). Grau Cormack-Lehane ≥ 3 foi definido como Laringoscopia Difícil. A sensibilidade, especificidade, valores preditivos positivo e negativo foram avaliados para todos os testes. A análise multivariada com regressão logística foi usada para criar modelos preditivos. Resultados: Um modelo incorporando CML, TMLS, EC, DHM-EM e CC/DTM demonstrou alta precisão prognóstica (x2(5) = 109,12, p < 0,001, AUC = 0,86, p < 0,001). A sensibilidade, especificidade e valor preditivo negativo foram 82,3%, 74,8% e 97,4%, respectivamente. Um segundo modelo incluindo duas medidas que não necessitavam da cooperação do paciente (CC/DTM e DHM-EM) demonstrou bom desempenho prognóstico (x2 (2) = 63,5; p < 0,001; AUC = 0,77, p < 0,001). Entre os testes individuais, EC teve a maior sensibilidade (78,5%) e valor preditivo negativo (96%). Conclusões: O modelo de cinco variáveis incorporando CML, TMLS, EC, DHM-EM e CC/DTM mostrou valor preditivo satisfatoriamente alto para laringoscopia difícil. Um modelo que incluísse CC/DTM e DHM-EM poderia ser útil em pacientes com incapacidade. O preditor individual mais preciso foi EC.
Subject(s)
Humans , Male , Female , Adult , Aged , Models, Statistical , Point-of-Care Testing , Laryngoscopy , Multivariate Analysis , Predictive Value of Tests , Prospective Studies , Sensitivity and Specificity , Middle AgedABSTRACT
Background & objectives: Hydroxyethyl starches (HES) 130/0.4 (Voluven®) and 130/0.42 (Venofundin®) impair coagulation less than older HES solutions with higher molecular weight and molar substitution. Thus, these may be used in high doses up to 50 ml/kg/day. The aim of this study was to investigate and compare the effects of HES 130/0.4 versus HES 130/0.42 on coagulation after the intraoperative infusion of 30 ml/kg in patients undergoing major abdominal surgery. Methods: Fifty two patients scheduled for elective major abdominal surgery were randomized to receive 30 ml/kg of HES 130/0.4 or HES 130/0.42 intraoperatively. Coagulation variables were assessed before and after infusion of the colloid solution using thrombelastography. Results: Data from 49 patients, 25 patients in the HES 130/0.4 and 24 in the HES 130/0.42 group, were analyzed. Measurements of reaction time, kinetic time, α-angle, maximum amplitude and coagulation index before and after colloid infusion did not differ between the groups. Within each group, after colloid infusion, reaction time did not change significantly, while α-angle, maximum amplitude and coagulation index values were significantly decreased (P<0.01, P<0.001 and P<0.001, respectively in HES 130/0.4 group and P<0.01, P<0.001 and P<0.01, respectively in HES 130/0.42 group). Kinetic time was significantly increased (P<0.001) in both the groups. In both groups, all thrombelastographic measurements after colloid infusion were found within normal limits. Interpretation & conclusions: HES 130/0.4 and HES 130/0.42 showed similar, not clinically significant effects on coagulation, as assessed by thrombelastography, when a dose of 30 ml/kg was administered in patients undergoing major abdominal surgery.