BACKGROUND: There has been controversy about predicting difficult LMA insertion and suboptimal position. Our aim was to evaluate bedside predictors for difficult LMA ProSeal(TM) (PLMA) insertion and suboptimal position. METHODS: As the potential predictive factors for difficult PLMA insertion and suboptimal position, we considered male gender, increased body mass index (BMI), seven individual items suggesting difficult airway [modified Mallampati classification > or = III, inter-incisor distance < or = 5 cm, thyromental distance < or = 6.5 cm, head/neck movement < or = 90degrees, history of difficult intubation, buck of teeth > or = moderate, upper lip bite test (ULBT) > or = II] and > or = 3 of total airway score which is the sum of scores assessed by a score of 0, 1, 2 in seven individual items. The PLMA position was assessed by fiberoptic bronchoscopy to determine whether these predictors predict suboptimal position of PLMA (fiberoptic score < 3, as graded on a standard fiberopitc scale). We also investigated the effect of predictive factors on the failure of the first insertion of PLMA and time required for successful Proseal LMA insertion on the first attempt. RESULTS: 154 patients were enrolled in the study. The total airway score did have a significant relationship with the fiberoptic findings. The male gender and ULBT I of investigated predictors did significantly correlate with failure on the first insertion of PLMA. We did not find any significant relationship between the predictive factors and PLMA insertion time on the first attempt. CONCLUSIONS: The male gender and ULBT I indicate difficult PLMA insertion, and the total airway score > or = 3 indicates suboptimal position of PLMA.
Body Mass Index ; Bronchoscopy ; Classification ; Humans ; Intubation ; Laryngeal Masks* ; Lip ; Male ; Tooth

BACKGROUND: Head and neck anatomy affects the laryngeal mask airway (LMA) cuff volume. The purpose of this study was to identify physical parameters that can be standardized to predict LMA cuff volume and measure the optimal and minimal LMA cuff volume in adults. METHODS: The predictors of volume or pressure of the LMA cuff were investigated in 167 patients. Manufacturers recommend a maximal cuff pressure (MCP) (i.e., 40 ml for size 5, 30 ml for size 4), an optimal cuff volume (OCV) at a cuff pressure of 60 cmH2O, and a minimal cuff volume (MCV) just before audible air leakage. The physical parameters measured included height, weight, body mass index, modified Mallampati classification (MMP), neck circumference, neck length, and thyro-mental distance. Data were analyzed by stepwise multilinear analysis. RESULTS: The regression equations (REs) were as follows: OCV (1.2 + [0.1 × height] + [0.5 × neck length]); MCV for men (−35.7 + [0.25 × height] + [0.7 × neck length] − [4.1 × MMP]); and MCV for women (−42.5 + [0.27 × height] + [0.75 × neck length] − [2.5 × MMP]). The mean values were as follows: MCP > 200 cmH2O, minimal cuff pressure < 20 cmH2O, OCV of 24.7 ml for men and 15.9 ml for women, and MCV of 12.1 ml for men and 7.1 ml for women. CONCLUSIONS: LMA cuff volume is estimated from the patient's height, neck length, and MMP. The RE for calculating the MCV shows a high correlation with height, neck length, and MMP.
Adult ; Airway Management ; Body Weight ; Classification ; Female ; Head ; Humans ; Laryngeal Masks* ; Male ; Neck ; Physical Examination*

BACKGROUND: Head and neck anatomy affects the laryngeal mask airway (LMA) cuff volume. The purpose of this study was to identify physical parameters that can be standardized to predict LMA cuff volume and measure the optimal and minimal LMA cuff volume in adults. METHODS: The predictors of volume or pressure of the LMA cuff were investigated in 167 patients. Manufacturers recommend a maximal cuff pressure (MCP) (i.e., 40 ml for size 5, 30 ml for size 4), an optimal cuff volume (OCV) at a cuff pressure of 60 cmH2O, and a minimal cuff volume (MCV) just before audible air leakage. The physical parameters measured included height, weight, body mass index, modified Mallampati classification (MMP), neck circumference, neck length, and thyro-mental distance. Data were analyzed by stepwise multilinear analysis. RESULTS: The regression equations (REs) were as follows: OCV (1.2 + [0.1 × height] + [0.5 × neck length]); MCV for men (−35.7 + [0.25 × height] + [0.7 × neck length] − [4.1 × MMP]); and MCV for women (−42.5 + [0.27 × height] + [0.75 × neck length] − [2.5 × MMP]). The mean values were as follows: MCP > 200 cmH2O, minimal cuff pressure < 20 cmH2O, OCV of 24.7 ml for men and 15.9 ml for women, and MCV of 12.1 ml for men and 7.1 ml for women. CONCLUSIONS: LMA cuff volume is estimated from the patient's height, neck length, and MMP. The RE for calculating the MCV shows a high correlation with height, neck length, and MMP.
Adult ; Airway Management ; Body Weight ; Classification ; Female ; Head ; Humans ; Laryngeal Masks* ; Male ; Neck ; Physical Examination*

BACKGROUND: Geriatric patients are susceptible to respiratory and hemodynamic adverse events during endotracheal intubation and extubation due to anatomic and physiological changes with aging. Supraglottic airway devices (SADs) provide reduced airway morbidity and increased hemodynamic stability in adults. However, studies that have compared the clinical performance of SADs in geriatric patients are limited. Therefore, we evaluated the clinical performance of airway management with i-gel® and laryngeal mask airway Supreme (LMA Supreme™) in geriatric patients. METHODS: The subjects were American Society of Anesthesiologists physical status classification I–III geriatric (65–85 years) patients who underwent elective surgery with general anesthesia and were randomly allocated into the i-gel® group and the LMA Supreme™ group. We compared the time for successful insertion on a first attempt as a primary outcome, and the secondary outcomes were success rate, ease of insertion, maneuver for successful ventilation, oropharyngeal leak pressure, gastric insufflation, fiberoptic view grades, ventilator problems, and adverse events. RESULTS: Insertion time was significantly shorter for the i-gel® than the LMA Supreme™ (21.4 ± 6.8 vs. 29.3 ± 9.9 s; P = 0.011). The i-gel® was also easier to insert than the LMA Supreme™ (P = 0.014). Gastric insufflation was less frequent with the i-gel® than the LMA Supreme™ (0% vs. 31.3%; P = 0.013). Other measurements were comparable between groups. CONCLUSIONS: Both devices can be safely applied to geriatric patients with similar success rates and oropharyngeal leak pressures. However, inserting the i-gel® was faster and easier compared to the LMA Supreme™ in geriatric patients.
Adult ; Aging ; Airway Management ; Anesthesia, General ; Classification ; Hemodynamics ; Humans ; Insufflation ; Intubation ; Intubation, Intratracheal ; Laryngeal Masks ; Prospective Studies ; Ventilation ; Ventilators, Mechanical

Size selection of the laryngeal mask airway (LMA) Classic based on actual body weight remains a common practice. However, ideal body weight might allow for a better size selection in obese patients. The purpose of our study was to compare the utility of ideal body weight and actual body weight when choosing the appropriate size of the LMA Classic by a randomized clinical trial. One hundred patients with age 20 to 70 yr, body mass index > or =25 kg/m2, and the difference between LMA sizes based on actual weight and ideal weight were allocated to insert the LMA Classic using either actual body weight or ideal body weight in a weight-based formula for size selection. After insertion of the device, several variables including insertion parameters, sealing function, fiberoptic imaging, and complications were investigated. The insertion success rate at the first attempt was lower in the actual weight group (82%) than in the ideal weight group (96%), even it did not show significant difference. The ideal weight group had significantly shorter insertion time and easier placement. However, fiberoptic views were significantly better in the actual weight group. Intraoperative complications, sore throat in the recovery room, and dysphonia at postoperative 24 hr occurred significantly less often in the ideal weight group than in the actual weight group. It is suggested that the ideal body weight may be beneficial to the size selection of the LMA Classic in overweight patients (Clinical Trial Registry, NCT 01843270).
Adult ; Aged ; *Body Weight ; Equipment Design ; Female ; Human Engineering/*methods ; Humans ; Ideal Body Weight/*physiology ; Laryngeal Masks/*classification ; Male ; Middle Aged ; Overweight/*physiopathology ; Prosthesis Fitting/*methods ; Reproducibility of Results ; Republic of Korea ; Sensitivity and Specificity ; Young Adult