Rapid sequence induction in Paediatric Anaesthesia
A narrative review
Trends in Anaesthesia and Critical Care
June 2023 by Dr Christoher Dawson
Bronchial aspiration - dangerous for our patients and medico-legally and morally dangerous for providers. This narrative review presents an overview of rapid sequence induction (RSI) as it pertains to paediatric patients.
Few large studies have examined the incidence of pulmonary aspiration in children and its risk factors. The Near 4 Kids trial found a 4% incidence of regurgitation during intubation, with 0.7% incidence of clinical aspiration, with age >8 and haemodynamic instability among the risk factors. The APRICOT study found 0.1% of their patients had aspiration, with roughly 50% at induction and 50% at emergence / maintenance.
There is a large heterogeneity of RSI techniques in the paediatric literature beyond the classically described pre-oxygenate + muscle relaxant + cricoid pressure + no ventilation. One large survey described in this review noted only 24% of respondents performed cricoid pressure during RSI and nearly a third performed low pressure ventilation. In the APRICOT study half the patients were ventilated and half were not, and 90% of them had muscle relaxants. (Notably in a recent ANZCA survey [Mistry et al, Anaesthesia and Intensive Care 2021] the numbers were closer to 75% amongst those who use cricoid).
The article presents several risk factors for aspiration/indications for RSI in children which would be near identical to a list for adults. Some more information around specific risk factors that might be more unexpected in children versus adults and why may have been useful for the occasional paediatric anaesthetist.
In terms of fasting the authors note that European recommendations on preoperative fasting in children suggest assessing gastric contents with ultrasound in children before emergency surgery, which may present challenges depending on operator skill and patient compliance.
The article presents a preparation checklist for equipment for RSI. Again, no real surprises here but it may be a useful checklist to have to hand in a crisis. They suggest use of video laryngoscopy as first choice where available, noting there is evidence in infants that it improves first pass success and reduces complications.
Skating delicately over the huge area of controversy that is use of cricoid pressure, the authors state "many paediatric anaesthetists wonder whether cricoid is performed as a ritual", noting the potential issues relating to cricoid pressure in children - smaller cricoid size, application of correct pressure and potential for decrease in lower oesophageal sphincter tone leading to aspiration.
They note that several European paediatric anaesthesia societies no longer recommended use of cricoid pressure during RSI, and that the Near 4 Kids trial showed an increased incidence of aspiration with the use of cricoid - though this was not significant after adjusting for patient and practice factors. Notably cricoid pressure can help prevent gastric insufflation when ventilating children <1 year old. As always - more RCTs are needed! The authors’ final opinion is not to recommend cricoid pressure.
The authors give a concise summary of a suggested standard operating procedure for RSI in children. Mostly sensible stuff that fits with local practice. Injecting opioids or atracurium slowly and use of thiopentone might raise eyebrows.
The planning and equipment as described in this article assumes that all patients will have an IV placed as part of the preparation for RSI. This is all well and good, but discussion around use of sedatives and adjuncts (eg N2O) and their safety (or lack thereof) would be helpful for the children who would not tolerate IV placement.
With regards to oxygenation the authors note the difficulty in pre-oxygenating smaller, non-compliant children. They suggest a number of strategies to achieve a “controlled RSI” which have been demonstrated to have improved outcomes:
• gentle ventilation - <8mL/kg, APL at 10cm, which appears to only cause gastric insufflation in children <1 year old
• maintain FRC by fixing APL at 10cm and applying “manual high frequency tiny ventilation”
• nasal oxygenation via standard nasal prongs during intubation
The authors do not describe how nasal oxygenation could be achieved smoothly without interfering with effective mask ventilation, if desired.
For the child in whom does aspiration occur the authors give a nice summary of management techniques - head down, suction, bronchoscopy if large pieces obstruct. Use PEEP, more suction and bronchodilators depending on the clinical picture. Systematic bronchial-alveolar lavage, chest XR and steroids are not routinely required. Handy disposition suggestions are also provided - asymptomatic patients can be sent to their pre-planned destination (home / ward) after two hours of observation, while symptomatic patients should go to the ward, and those requiring ventilatory support or if SaO2 cannot be maintained over 90% should go to ICU.
Finally, a timely reminder of the use of capnography and consideration of human factors in confirmation of tracheal intubation, particularly in the light of recent publicised tragic events: no trace = wrong place.
This review gives a succinct summary of the issues surrounding RSI in children and the important steps to consider, with useful discussion of some specific techniques that can be applied.
It could have used a little more depth as to the evidence base for some of their recommendations, or more included more recommendations from international societies where the evidence base is weak. It would be useful to know more about which risk factors for pulmonary aspiration are more prevalent in children and why, in order to better prevent these events.
Some more real-world consideration of management of the non-compliant child without an IV who requires an RSI would be helpful.