Supraglottic Airway Device Placement Research Articles

Intramuscular alfaxalone with or without buprenorphine or hydromorphone provides sedation with minimal adverse effects in healthy rabbits (Oryctolagus cuniculus) in a randomized blinded controlled trial.

To evaluate the effects of alfaxalone administered IM with or without buprenorphine or hydromorphone in healthy rabbits (Oryctolagus cuniculus). 24 male rabbits undergoing elective orchiectomy between August 21, 2021, and November 6, 2021. In this controlled clinical trial, rabbits were randomly assigned to receive alfaxalone (4 mg/kg, IM) alone (group A; n = 8) or with buprenorphine (0.03 mg/kg, IM; group BA; 8) or hydromorphone (0.1 mg/kg, IM; group HA; 8). Vital signs and sedation scores were recorded immediately prior to (T0) and 10 minutes after (T1) treatment. Ease of IV catheter placement and pain scores were also evaluated. All rabbits received ketamine (2.5 mg/kg, IV), midazolam (0.13 mg/kg, IV), and meloxicam (0.5 mg/kg, SC) before orchiectomy but after IM treatments. Results were compared across groups with ANOVA or Fisher exact tests and across time with paired t tests. Sedation score, median time to recumbency, and ease of catheter placement did not differ among groups. Supraglottic airway device placement was possible for 1 rabbit in group A, 1 in group BA, and 2 in group HA. Mean respiratory rate at T1 versus T0 was significantly decreased for groups BA (63.8 vs 128.6 breaths/min) and HA (66.7 vs 123.2 breaths/min). Mean postoperative pain scores were significantly lower for rabbits in group HA (0.58), compared with those in groups A (2.25) and BA (2.06). All 3 treatments provided reliable sedation; however, alfaxalone (4 mg/kg, IM) combined with hydromorphone (0.1 mg/kg, IM) may be a better choice for painful procedures.

Comparison of SaCoVLM™ video laryngeal mask-guided intubation and i-gel combined with flexible bronchoscopy-guided intubation in airway management during general anesthesia: a non-inferiority study

BackgroundWhen a difficult airway is unanticipatedly encountered and the initial laryngoscopic intubation fails, a supraglottic airway device (SAD) may be placed to aid ventilation and oxygenation, and act as a conduit for intubation. SaCoVLM™, as new SAD, can offer a direct vision to guide intubation. However, no study has evaluated the performance of SaCoVLM™ video laryngeal mask (VLM) intubation and i-gel combined with flexible bronchoscopy (FB)-guided intubation in airway management during general anesthesia.MethodsA total of 120 adult patients were randomly allocated into the SaCoVLM™ group (Group S) and i-gel group (Group I). After induction of general anesthesia, guided tracheal intubation under direct vision of the SaCoVLM™ was conducted in Group S, while Group I received FB-guided tracheal intubation using the i-gel. The success rate of SAD placement, first-pass success rate of guided tracheal tube placement, and total success rate in both groups were recorded. The time for SAD placement, time for guided tracheal intubation, total intubation time (time for SAD placement and intubation), glottic exposure grading and postoperative intubation complications (i.e., dysphagia, hoarseness, pharyngalgia, etc.) of both groups were also compared.ResultsThe first-time success rate of SAD placement was 98% in two groups. The first-pass success rate of guided endotracheal intubation was 92% in Group S and 93% in Group I (P = 0.74 > 0.05). The total intubation time was 30.8(± 9.7) s and 57.4(± 16.6) s (95% CI = -31.5 to -21.7) in Group S and Group I, respectively (P < 0.01). The total complication rate was 8% in Group S and 22% in Group I (P < 0.05). The laryngeal inlet could be observed in the S group through the visual system of SaCoVLM™. No dysphagia or hoarseness was reported.ConclusionSaCoVLM™ can reveal the position of laryngeal inlet, thus providing direct vision for tracheal intubation. SaCoVLM™ -guided intubation is faster, and does not rely on FB, compared to i-gel combined with FB-guided intubation. Besides, SaCoVLM™ has a lower post-intubation complication rate.Trial registrationChinese Clinical Trials Registry (ChiCTR2100043443); Date of registration: 18/02/2021.

Development and Testing of a Sedation Scale for Use in Rabbits (Oryctolagus cuniculus).

In biomedical research, rabbits are commonly sedated to facilitate a variety of procedures. Developing a sedation assessment scale enables standardization of levels of sedation and comparisons of sedation protocols, and may help in predicting sedation level requirements for different procedures. The goal of this study was to develop a rabbit sedation assessment scale using a psychometric approach. We hypothesized that the sedation scale would have construct validity, good internal consistency, and reliability. In a prospective, randomized, blinded study design, 15 (8 females, 7 males) healthy 1-y-old New Zealand white rabbits received 3 intramuscular treatments: midazolam (0.5 mg/kg; n = 6); midazolam (1.5 mg/kg)-ketamine (5 mg/kg; n = 7); and alfaxalone (4 mg/kg)-dexmedetomidine (0.1 mg/kg)-midazolam (0.2 mg/kg; n = 3). One rabbit received 2 treatments. A sedation scale was developed by using psychometric methods, with assessment performed by 6 independent raters who were blind to treatment. Final sedation scale items included posture, palpebral reflex, orbital tightening, lateral recumbency, loss of righting reflex, supraglottic airway device placement, toe pinch, and general appearance. The scale showed construct validity, good to very good interrater reliability for individual items (6 raters; intraclass correlation coefficient, 0.671 to 0.940), very good intrarater reliability (5 raters; intraclass correlation coefficient, 0.951 to 0.987), and excellent internal consistency (Cronbach α, 0.947). The sedation scale performed well under the conditions tested, suggesting that it can be applied in a wider range of settings (different populations, raters, sedation protocols).

Effect of endotracheal intubation and supraglottic airway device placement during cardiopulmonary resuscitation on carotid blood flow over resuscitation time: An experimental porcine cardiac arrest study

BackgroundSupraglottic airway devices (SGDs) are widely used during the resuscitation of out-of-hospital cardiac arrest (OHCA). The effect of SGDs on carotid blood flow (CBF) as resuscitation time passes is controversial. We assessed the effects of endotracheal intubation (ETI) and 3 types of SGD placement on CBF over time in prolonged resuscitation through an experimental porcine cardiac arrest study. MethodsWe conducted a randomized crossover study using 12 female pigs. After 4 min of untreated ventricular fibrillation, 3 pairs of ETI for 3 min and each type of SGD placement, including Combitube, I-gel, and laryngeal mask airway, for 3 min were conducted. The order of the 3 pairs of ETI and SGD were randomly assigned for each pig. We measured physiological parameters including CBF and mean arterial pressure (MAP). We compared CBF and MAP between the last 1 min of the insertion period for each of the 3 types of SGD and the preceding ETI period. Trends of CBF and MAP according to ETI and SGD transition were also plotted during the prolonged resuscitation duration. ResultsCBF decreased after inserting I-gel and Combitube compared to ETI (mean difference (95% CI): −685 ml (−1052 to −318) for Combitube, −369 ml (−623 to −114) for I-gel). MAP subsequently decreased after transitioning airway devices as resuscitation was prolonged, regardless of the device type. The mean CBF during the transition from ETI to SGD decreased by −480 ml (95% CI: −675 to −286), but the decrease in CBF during the transition from SGD to ETI was only −4 ml (95% CI: −182 to 175). ConclusionSGD placement was associated with decreased carotid blood flow during cardiopulmonary resuscitation in an experimental porcine model. As time passed during prolonged resuscitation, reduction in CBF was aggravated after the transition to SGD placement compared to the reduction after the transition to ETI. This study was approved by the study institution IACUC 16-0140-S1A0.

Abstract 168: Association Between Prehospital Advanced Airway Management for Pediatric Out-of-Hospital Cardiac Arrest and Survival

Introduction: It is unclear whether prehospital advanced airway management (AAM: endotracheal intubation and supraglottic airway device placement) for pediatric patients with out-of-hospital cardiac arrest (OHCA) improves patient outcomes. Objective: To test the hypothesis that prehospital advanced airway management during pediatric OHCA is associated with patient outcomes. Methods: We conducted a secondary analysis of a nationwide, prospective, population-based OHCA registry in Japan. We included pediatric patients (&lt;18 years) with OHCA in whom emergency medical services (EMS) personnel resuscitated and transported to medical institutions during 2014 and 2015. The primary outcome was one-month survival. Secondary outcome was one-month survival with favorable functional outcome, defined as cerebral performance category score 1 or 2. Patients who received AAM during cardiopulmonary resuscitation by EMS personnel at any given minute were sequentially matched with patients at risk of receiving AAM within the same minutes based on time-dependent propensity score calculated from a competing risk regression model in which we treated prehospital return of spontaneous circulation as a competing risk event. Results: We included 2,548 patients; 1,017 (39.9%) were infants (&lt;1 year), 839 (32.9%) were children (1 year to 12 years), and 692 (27.2%) were adolescents. Of the 2,548, included patients, 336 (13.2%) underwent prehospital AAM during cardiac arrest. In the time-dependent propensity score matched cohort (n = 642), there were no significant differences in one-month survival (AAM: 32/321 [10.0%] vs. no AAM: 27/321 [8.4%]; odds ratio, 1.33 [95% CI, 0.80 to 2.21]) and one-month survival with favorable functional outcome (AAM: 6/321 [1.9%] vs. no AAM: 5/321 [1.6%]; odds ratio, 1.48 [95% CI, 0.41 to 5.40]). Conclusions: Among pediatric patients with OHCA, we found no associations between prehospital AAM and favorable patient outcomes.

Male requires a higher median target effect-site concentration of propofol for I-gel placement when combined with dexmedetomidine

ObjectiveThe supraglottic airway device (SAD) can be used for airway management of spontaneous breathing patients, and propofol is commonly applied for the SAD placement. This study was designed to assess the effect of gender on median target effect-site concentration (Ce50) of propofol for I-gel placement when combined with dexmedetomidine. Material and method19 males and 18 females, aged 18 to 59 and undergoing elective surgery, were enrolled. After intravenous infusion of dexmedetomidine 1.0μg/kg over 10min followed by continuous infusion of 0.4μg/kg/h, target-controlled infusion of propofol under Marsh model was started and the initial Ce of propofol was set at 4.79μg/mL and 4.35μg/mL in the male and female patients, respectively. The I-gel was inserted when the Ce of propofol reached the pre-set concentration and bispectral index value was less than 60. The Ce of propofol required for I-gel placement was determined by the Dixon up-and-down method. ResultsThe Ce50 (95% confidence interval) of propofol required for I-gel placement were 4.082μg/mL (3.798–4.332μg/mL) and 3.509μg/mL (3.266–3.749μg/mL) in male and female patients, respectively, with a significantly higher Ce50 in males. ConclusionWhen combined with dexmedetomidine, males require a higher Ce50 of propofol for I-gel placement compared to females.

Comparison of a Supraglottic Airway Device (v-gel®) with Blind Orotracheal Intubation in Rabbits

Achieving a secure airway in rabbits is generally considered more difficult than in cats or dogs. Their relatively large tongue, small oropharyngeal cavity and glottis limit direct visualization. A rabbit-specific supraglottic airway device (SGAD) may offer benefits over blind orotracheal intubation. Fifteen adult New Zealand white rabbits were randomized to SGAD or orotracheal intubation (ETT). All animals were sedated with dexmedetomidine (0.1 mg kg-1 IM) and midazolam (0.5 mg kg-1 IM), followed by induction with alfaxalone (0.3 mg kg-1 IV). Two CT scans of the head and neck were performed, following sedation and SGAD/ETT placement. The following were recorded: time to successful device insertion, smallest cross-sectional airway area, airway sealing pressure, and histological score of tracheal tissue. Data were analyzed with a Mann-Whitney test. Two rabbits were excluded following failed ETT. Body masses were similar [ETT; n = 6, 2.6 (2.3-4.5) kg, SGAD; n = 7, 2.7 (2.4-5.0) kg]. SGAD placement was significantly faster [33 (14-38) s] than ETT [59 (29-171) s]. Cross-sectional area (CSA) was significantly reduced from baseline [12.2 (6.9-3.4) mm2] but similar between groups [SGAD; 2.7 (2.0-12.3) mm2, ETT; 3.8 (2.3-6.6) mm2]. In the SGAD group, the device tip migrated into the laryngeal vestibule in 6/7 rabbits, reducing the CSA. ETT airway seals were higher [15 (10-20) cmH2O], but not significant [SGAD; 5 (5-20) cmH2O, p = 0.06]. ETT resulted in significantly more mucosal damage [histological score 3.3 (1.0-5.0)], SGAD; 0.67 (0.33-3.67). The SGAD studied was faster to place and caused less damage than orotracheal intubation, but resulted in a similar CSA.

All India Difficult Airway Association 2016 guidelines for the management of unanticipated difficult tracheal intubation in obstetrics.

The various physiological changes in pregnancy make the parturient vulnerable for early and rapid desaturation. Severe hypoxaemia during intubation can potentially compromise two lives (mother and foetus). Thus tracheal intubation in the pregnant patient poses unique challenges, and necessitates meticulous planning, ready availability of equipment and expertise to ensure maternal and foetal safety. The All India Difficult Airway Association (AIDAA) proposes a stepwise plan for the safe management of the airway in obstetric patients. These guidelines have been developed based on available evidence; wherever robust evidence was lacking, recommendations were arrived at by consensus opinion of airway experts, incorporating the responses to a questionnaire sent to members of the AIDAA and the Indian Society of Anaesthesiologists (ISA). Modified rapid sequence induction using gentle intermittent positive pressure ventilation with pressure limited to ≤20 cm H2O is acceptable. Partial or complete release of cricoid pressure is recommended when face mask ventilation, placement of supraglottic airway device (SAD) or tracheal intubation prove difficult. One should call for early expert assistance. Maternal SpO2 should be maintained ≥95%. Apnoeic oxygenation with nasal insufflation of 15 L/min oxygen during apnoea should be performed in all patients. If tracheal intubation fails, a second- generation SAD should be inserted. The decision to continue anaesthesia and surgery via the SAD, or perform fibreoptic-guided intubation via the SAD or wake up the patient depends on the urgency of surgery, foeto-maternal status and availability of resources and expertise. Emergency cricothyroidotomy must be performed if complete ventilation failure occurs.

Airway management using a supraglottic airway device without endotracheal intubation for positive ventilation of anaesthetized rats

Endotracheal intubation is often necessary for positive pressure ventilation of rats during open thoracic surgery. Since endotracheal intubation in rats is technically difficult and is associated with numerous complications, many techniques using various devices have been described in the scientific literature. In this study, we compared the effectiveness of airway management of a home-made supraglottic airway device (SAD), which is cheap to fabricate and easy to place with that of an endotracheal intubation tube in enflurane-anaesthetized rats. Twenty male Sprague-Dawley rats (200-300 g) were randomly assigned to two equal groups for positive pressure mechanical ventilation using either the SAD or an endotracheal intubation tube. The carotid artery of each rat was cannulated for continuous blood pressure measurements and obtaining blood samples for determination of oxygen tension, carbon dioxide tension, and blood acidity before, during and after SAD placement or endotracheal intubation. Proper placement of the SAD was confirmed by observing chest wall movements that coincided with the operation of the mechanical ventilator. No complications and adverse events were encountered in the rats in which the SAD was placed, during SAD placement and immediate removal, during their mechanical ventilation through the SAD, and one week after SAD removal. From the results of blood gas analyses, we conclude that anaesthetized rats can be successfully ventilated using an SAD for open thoracic surgery.