Evaluation of thyromental height as a predictor of difficult laryngoscopy and difficult intubation: a cross-sectional observational study

Abstract Background and objectives Several anthropometric measurements have been suggested to identify a potentially difficult airway. We studied thyromental height (TMH) as a predictor of difficult laryngoscopy and difficult intubation. We also compared TMH, ratio of height to thyromental distance (RHTMD), and thyromental distance (TMD) as predictors of difficult airway. Methods This cross-sectional observational study was conducted in 300 adult surgical patients requiring tracheal intubation. Preoperatively airway characteristics were assessed. Standard anesthesia was administered. Degree of difficulty with mask ventilation, laryngoscopic view, duration of laryngoscopy, and difficulty in tracheal intubation (intubation difficulty scale score) were noted. Multivariate logistics regression analysis was performed to identify independent predictors for difficult laryngoscopy. Results Laryngoscopy was difficult in 46 of 300 (15.3%) patients; all 46 patients had Cormack-Lehane grade 3 view. Duration of laryngoscopy was 27 ± 11 s in patients with difficult laryngoscopy and 12.7 ± 3.9 s in easy laryngoscopy; p= 0.001. Multivariate analysis identified that TMH, presence of short neck, and history of snoring were independently associated with difficult laryngoscopy. Incidence of difficult intubation was 17.0%. A shorter TMH was associated with higher IDS scores; r = -0.16, p= 0.001. TMH and duration of laryngoscopy were found to be negatively correlated; a shorter TMH was associated with a longer duration of laryngoscopy; r = -0.13, p= 0.03. The cut-off threshold value for TMH in our study is 4.4 cm with a sensitivity of 66% and a specificity of 54%. Conclusion Thyromental height predicts difficult laryngoscopy and difficult intubation. TMD and RHTMD did not prove to be useful as predictors of difficult airway.

Assessment of hypertension control in chronic kidney disease patients by ambulatory blood pressure monitoring.

BACKGROUND: Inadequate control of blood pressure (BP) increases cardiovascular mortality and morbidity in chronic kidney disease (CKD) and renal transplant patients. 24 hour ambulatory BP was recorded to evaluate the adequacy of BP control in these patients. METHODS: 60 CKD patients (25 conservative therapy, 16 maintenance hemodialysis, 19 renal transplant patients) were studied prospectively. After achieving clinic BP control, 24 hour ambulatory BP was recorded at 1 and 6 months. The patients were followed up for one year. RESULTS: Mean daytime and nighttime systolic blood pressure (SBP) both at 1 month and at 6 month was higher in non-survivors than in survivors. The survivors had better control of their daytime (p=0.018) as well as nighttime SBP levels (p=0.018) at 6 months compared to those at 1 month. Survivors achieved nocturnal dipping of SBP at 1 and 6 months (p=0.047, p=0.025, respectively). Non-survivors failed to achieve lower daytime (p=0.375) or nighttime SBP (p=0.254) at 6 months as compared to SBP at 1 month in spite of optimizing antihypertensive therapy. Daytime (p=0.022) and nighttime (p=0.029) diastolic BP (DBP) in the non-survivors was higher than in survivors. Nocturnal dip in DBP was not seen in either survivors at 1 (p=0.177) and 6 months (p=0.434) or non-survivors at 1 (p=0.408) and at 6 months (p=0.081). Renal transplant patients did not exhibit nocturnal dipping of BP. CONCLUSION: We conclude that, unlike survivors, there was worsening of 24 hour BP control in non-survivors. ABPM has a role in better management of total BP burden in CKD patients.