The influence of different patient positions during rapid induction with severe regurgitation on the volume of aspirate and time to intubation: a prospective randomised manikin simulation study

Abstract

BackgroundAspiration is a main contributor to morbidity and mortality in anaesthesia. The ideal patient positioning for rapid sequence induction remains controversial. A head-down tilt and full cervical spine extension (Sellick) might prevent aspiration but at the same time compromise airway management. We aimed to determine the influence of three different positions during induction of general anaesthesia on the volume of aspirate and on participants’ airway management.MethodsEighty-four anaesthetic trainees and consultants participated in a prospective randomised simulation study. Anaesthesia was induced in reverse Trendelenburg position (+ 15°) in a manikin capable of dynamic fluid regurgitation. Participants were randomised to change to Trendelenburg position (− 15°) a) as soon as regurgitation was noticed, b) as soon as ‘patient’ had been anaesthetised, and c) as soon as ‘patient’ had been anaesthetised and with full cervical spine extension (Sellick). Primary endpoints were the aspirated volume and the time to intubation. Secondary endpoints were ratings of the laryngoscopic view and the intubation situation (0–100 mm).ResultsCombining head-down tilt with Sellick position significantly reduced aspiration (p < 0.005). Median time to intubate was longer in Sellick position (15 s [8–30]) as compared with the head in sniffing position (10 s [8–12.5]; p < 0.05). Participants found laryngoscopy more difficult in Sellick position (39.3 ± 27.9 mm) as compared with the sniffing position (23.1 ± 22.1 mm; p < 0.05). Both head-down tilt intubation situations were considered equally difficult: 34.8 ± 24.6 mm (Sniffing) vs. 44.2 ± 23.1 mm (Sellick; p = n.s).ConclusionsIn a simulated setting, using a manikin-based simulator capable of fluid regurgitation, a − 15° head-down tilt with Sellick position reduced the amount of aspirated fluid but increased the difficulty in visualising the vocal cords and prolonged the time taken to intubate. Assessing the airway management in the identical position in healthy patients without risk of aspiration might be a promising next step to take.

An international survey about rapid sequence intubation of 10,003 anaesthetists and 16 airway experts

“…Three positions might include head-up (reverse-Trendelenburg); supine; and head-down (Trendelenburg). The head-up position provides better pre-oxygenation and possibly less reflux of gastric content, but the head-down position might be used in the event of vomiting [5,8,9]. The use of cricoid force is likewise controversial [10], as is the insertion and aspiration of a nasogastric tube before induction of anaesthesia [11].…”

Successful Endotracheal Intubation Using Suction-Assisted Laryngoscopy Assisted Decontamination Technique and a Head-Down Tilt Position during Massive Regurgitation

“…Due to our suspicion regarding the full stomach, we altered the Recently, according to manikin-based simulating studies, the head-down position and neck extension was observed to minimize airway contamination due to regurgitated contents [6,7].…”

An Evaluation of the Intubrite Laryngoscope in Simulated In-Hospital and Out-of-Hospital Settings by Individuals with No Clinical Experience: A Randomized, Cross-Over, Manikin Study

“…Endotracheal intubation is the gold standard for airway management in patients with respiratory failure [ 1 ]. It enables the implementation of adequate ventilation, and it protects the lungs against aspiration [ 2 ]. The correct performance of endotracheal intubation requires not only theoretical knowledge but also considerable manual skills, which should be continuously improved [ 3 ].…”

“…The correct performance of endotracheal intubation requires not only theoretical knowledge but also considerable manual skills, which should be continuously improved [ 3 ]. Despite the above-mentioned requirements, there are patients with difficult airways, gastric content, or blood in the oral cavity or nasopharynx, whose intubation may be extremely difficult, resulting in tooth damage, soft tissue injury, CNS hypoxia, or cardiac arrest [ 2 ].…”