Comparison of three methods in improving bag mask ventilation.

INTRODUCTION: Increasedlife expectancy in populations has brought along specific new scenarios in the fields of medicine for the elderly; prevalence of physical complications such as edentulism and patients with dentures is growing. Management of anesthesia and ventilation in this group of patients has turned into a great challenge. Some researchers suggest dentures to be left in place during bag-mask ventilation; yet, no unanimous agreement exists in this regard. METHODS: In a single blind randomized clinical trial, we studied 300 patients with ASA class I, II (American Society of Anesthesiologists), Mallampati class (I, II) and aged over 55 years in three groups. After induction of anesthesia, in group G dentures were removed and in each buccal space an eight-layer 10 × 10 cm gauze and an oral airway were placed. In group D, the dentures and an oral airway were left in place. In group C (control), after removing dentures just an appropriate oral airway was placed. Then, each three group underwent bag-mask ventilation. Success of bag-mask ventilation (BMV) was considered as increase in end-tidal carbon dioxide to more than 20 mmHg and back to baseline with fresh gas flow of 3 L/min and adjustable pressure limiting valve pressure of 20 cm H2O. Success rates were evaluated between groups. RESULTS: Effective BMV was possible in 91 (91%), 64 (64%) and 41 (41%) patients in groups G, D and C respectively. The differences were statistically significant. Successful BMV rate was significantly higher in female patients in group G compared to group C; 43/44 versus 25/46 individuals, P = 0.0001, odds ratio = 0.03, 95% confidence interval (0.00, 0.22). CONCLUSIONS: Leaving dentures in place in edentulous patients after inducing anesthesia improves bag-mask ventilation. However, placing folded compressed gauze in buccal space leads to more significant improvement in BMV compared to leaving dentures in place.

Sensitivity of palm print, modified mallampati score and 3-3-2 rule in prediction of difficult intubation.

BACKGROUND: This study evaluated the performance of modified Mallampati score, 3-3-2 rule and palm print in prediction of difficult intubation. METHODS: In a prospective descriptive study, data from 500 patients scheduled for elective surgery under general anesthesia were collected. An anesthesiologist evaluated the airway using mentioned tests and another anesthesiologist evaluated difficult intubation. Laryngoscopic views were determined by Cormack and Lehane score. Grades 3 and 4 were defined as difficult intubation. Sensitivity, specificity, positive predictive value, negative predictive value and Youden index were determined for all tests. RESULTS: Difficult intubation was reported in 8.9% of the patients. There was a significant correlation between body mass index and difficult intubation (P : 0.004); however, other demographic characteristics didn't have a significant correlation with difficult intubation. Among three tests, palm print was of highest specificity (96.46%) and modified Mallampati of highest sensitivity (98.40%). In a combination of the tests, the highest specificity, sensitivity and Youden index were observed when using all three tests together. CONCLUSIONS: Palm print has a high specificity for prediction of difficult intubation, but the best way for prediction of difficult intubation is using all three tests together.

Hyaluronidase in sub-Tenon's anesthesia for phacoemulsification, a double-blind randomized clinical trial.

AIM: To investigate the effect of hyaluronidase use on the quality of sub-Tenon's anaesthesia for phacoemulsification. METHODS: This was a randomized, double-blind clinical trial which was conducted at Nikookari Eye Hospital for 5 months. Forty-two eyes of candidates for phacoemulsification under sub-Tenon's anaesthesia were randomly allocated to two equal groups and received either 2 mL of lidocaine 2% solution with (LH), or without (L) addition of hyaluronidase (150IU/mL). Akinesia was assessed 15 minutes after sub-Tenon's injection. Patients and surgeon's satisfaction, as well as the postoperative pain (the visual analogue scale, VAS) were investigated after operation. The contingency tables (including the Chi-square or Fisher's exact tests, when appropriate) and parametric analysis (the independent samples t test) were used for statistical analysis. RESULTS: Complete akinesia (33.3% vs 4.8%, P=0.04), as well as the patients (85.7% vs 57.1%, P=0.04) and surgeon's satisfaction (87.5% vs 52.4%, P=0.02) were significantly more frequent in LH than in L group. The mean VAS was significantly lower in the same group (1.90±1.45 vs 3.00±1.55, P=0.04). CONCLUSION: Addition of hyaluronidase to lidocaine solution for sub-Tenon's anesthesia significantly improves the ocular akinesia, enhances the intra-operative patients and surgeons' satisfaction, and attenuates the postoperative pain.