Comparative study of oxiport laryngoscope blade versus miller laryngoscope blade for intubation in neonates and infants during general anesthesia, a prospective randomized controlled study

Neonates and infants are prone to oxygen desaturation during the induction of general anethesia. Pharyngeal oxygen insufflation has been shown to delay the onset and severity of desaturation during apnea. We took this comparative study with the hypothesis that Oxiport Blade delays the time of onset as well as severity of desaturation as compared to Miller Blade. Eighty neonates and infants undergoing general anesthesia with endotracheal intubation were recruited and randomly assigned into two groups:-Oxiport or Miller. (Laryngoscopy performed with Oxiport or Miller Blade respectively). Results were observed in terms of lowest SPO2 attained during Intubation with each Blade, time for 1% desaturation from baseline, desaturation rate, time for intubation and Heart rate. Data from 80 patients were available for final analysis: Oxiport(n=40)-Group O and Miller(n=40)-Group M. Mean lowest SPO2 attained during laryngoscopy in Group O was 97.77±2.81 and with Group M was 92.42±3.71 with a P-value<0.001. The Rate of Saturation achieved in Group O was 0.091±0.018 sec as compared to 0.342±0.122 sec in Group M and p value was <0.001. The time for 1% desaturation from baseline in Group O was 17.69±3.18 sec as compared to 10.4 ±2.09 sec in Group M with p value<0.001. The time for intubation and average heart rate were comparable in both the groups. Apnoeic Laryngeal Oxygen insufflation with Oxiport Blade decreases the incidence and severity of desaturation during intubation in neonates and infants.

Abstract 348: Laryngoscopy With Vallecula Blade Position is Associated With Higher Success in Tracheal Intubation for Critically Ill Children

Introduction: Classical teaching in pediatric laryngoscopy advocates the use of straight blades to be placed underneath the epiglottis, whereas curved blades are placed in the vallecula. Anesthesia studies suggest that straight blade positioning in the vallecula may be a satisfactory technique for small children. We sought to assess laryngoscope blade tip position during pediatric tracheal intubation (TI) and its association with intubation success. Methods: Observational single center study. Children undergoing TI from November 2017 until December 2018 in a pediatric emergency department (ED) and pediatric intensive care unit (PICU) using a CMAC video laryngoscope with recorded images available for review were eligible for inclusion. Patient and provider characteristics were obtained from quality improvement database. Each video was independently reviewed, and the blade tip position was determined by study personnel as ‘in vallecula’ or ‘under epiglottis’. TI success was defined as observation of the tube entering the trachea on video. Univariate analysis between blade tip position and success, as well as potential confounders, was performed by chi 2 testing. Multivariable logistic regression to determine the independent association between blade tip position and success while controlling for relevant confounders. Results: 95 TI attempts were analysed. 58% of attempts were successful (14/35 in infants, 8/15 in 1-7 yr old, 33/45 in 8+ yr, p=0.01). Blade tip position was in the vallecula for 20/31 (65%) attempts with curved blades and 23/64 (36%) with straight blades. In univariate analysis, TI attempts with blade tip position ‘in vallecula’ were significantly more successful than attempts with ‘under epiglottis’ (37% vs. 84%, p<0.001). Median duration of laryngoscopy was 41 sec (IQR 27-59), not significantly different between two blade tip positions (p=0.06). After controlling for patient age and blade type (potential confounders), TI attempts with blade tip ‘in vallecula’ was independently associated with success (aOR 7.2, 95% CI 2.6 - 20.1). Conclusion: During pediatric TI, laryngoscope blade tip position in the vallecula was independently associated with success when compared with placement under the epiglottis.

Abstract 167: Assessing Laryngoscope Blade Positioning During Pediatric Intubation by Video Review

Introduction: Classical teaching in laryngoscopy advocates the use of Miller (Straight) blades to be placed underneath the epiglottis and lift it, whereas for Macintosh (Curved) blades the tip is positioned in the vallecula. Published studies in anesthesia suggest that straight blade positioning in the vallecula may be a satisfactory technique for small children. However, there is no clear evidence of consistent implementation of this methodology in practice and associated intubation success. Objectives: To assess laryngoscope blade tip position during pediatric tracheal intubation in the emergency department (ED) and its association with intubation success and time of laryngoscopy. Methods: Single center retrospective observational cohort study. Children undergoing tracheal intubation in a tertiary pediatric ED under video-recorded conditions were eligible for inclusion. A CMAC video laryngoscope was used as first line device with the video feed recorded for review. Videos were reviewed and the blade tip position during intubation recorded by study personnel. Blade tip position was categorized as ‘Correct’ if the curved blade was in the vallecula or straight blade was lifting the epiglottis; otherwise the position was categorized as ‘Incorrect’. Time of laryngoscopy was defined as time from blade insertion to removal. Univariate analysis between covariates was done by Fisher’s exact testing for intubation success and by nonparametric methods for laryngoscopy time. Results: A total of 17 complete videos were included in the study. Mac blade was used correctly in 8/10 cases (80%); Miller was used correctly in 1/7 cases (14%). Among infants (≤ 12 months), the Miller was used incorrectly in 3/4 cases (75%). Intubation was successful in 9/9 cases (100%) with correct blade position and in 5/8 cases (63%) with incorrect position (p=0.04). There was no significant difference in mean calculated laryngoscopy time for correct versus incorrect blade tip position (37.90 ± 26.80 sec vs. 44.33± 15.22 sec, p=0.12) Conclusion: Correct position of the laryngoscope blade tip is associated with higher intubation success. There was no significant difference in the laryngoscopy time for both correct and incorrect blade position.

COMPARATIVE ASSESSMENT OF DIFFERENT TYPES OF LARYNGOSCOPES BLADES - MACINTOSH, MILLER AND MCCOY FOR LARYNGEAL VIEW AND PRESSOR RESPONSE

The laryngoscopy is known to have profound cardiovascular effects. This includes pressor response and tachycardia along with an increase in catecholamine concentration, mainly norepinephrine. The major cause of the sympathoadrenal response is believed to arise from stimulation of supraglottic region by laryngoscopic blade with tracheal tube placement and cuff inflation contributing little additional stimulation. Complications of pressor respo laryngoscopy include myocardial ischemia, cardiac failure, intracranial haemorrhage and increase in intracranial pressure. Hence the present study planned to evaluate the laryngeal view and pressor response by using three different blades – Macintosh, McCoy and Miller laryngoscopes. The study was planned in the Department of Anaesthesia in Andaman and Nicobar Islands Institute of Medical Science (ANIIMS), Port Blair India, From Jun 2016 to Jun 2017 . The 30 patient undergoing the Laryngoscopy were enrolled in the present study. For the 10 patients using the Macintosh Blade were divided in Group I. The next 10 patients using the Miller blade were considered in the Group II. The remaining 10 patients were studied by use of McCoy blade. The results in our study show that the MacCoy laryngoscope blade improves the visualization of the larynx and significantly attenuates haemodynamic parameters during laryngoscopy and intubation as compared to that with Macintosh laryngoscope blade. Keywords: Laryngoscopy, Intubation, pressor response, Macintosh, miller and Mccoy laryngoscopes, etc