Prehospital sedation best practices

A number of agencies have published sedation best practice guidelines [1-3]. With the exception of the NAEMSP statement on drug-assisted airway management, none of these are prehospital specific [4].

Adverse events have been reported in 10% of the prehospital population receiving sedation (most commonly hypoxia). Severe adverse events are relatively rare (2%) but may include severe hypoxia and cardiac arrest [5]. A consistent approach is important to achieve the best results for the patient in the safest manner possible, especially considering the uncontrolled environments faced in prehospital care. My approach incorporates components from each set of guidelines.

Evaluate the patient

The patient’s specific needs will determine the ideal level of sedation required.

Scared to fly? Anxiolysis.

Need cardioversion? Conscious sedation.

Trouble with the ventilator? Deep sedation.

Rapid sequence intubation (RSI)? General anesthesia.

Is pain a factor? Typically, patients do better if pain is controlled first and sedation is added after. This concept, referred to as anglo-sedation, is based on experience in the ICU [6].

The patient’s past medical history is also a factor. Have there been complications with anesthetics in the past? Does the patient have conditions that may exacerbate the side effects of the sedatives? Poor cardiac function may exacerbate hypotension; COPD may increase the risk of apnea or hypoxia. Obesity, sleep apnea, facial malformations or even facial hair can make ventilation and rescue airways more difficult.

The patient’s present condition will also influence sedation. Hemodynamic instability, dyspnea and hypoxia will influence my choice of sedation.

Sedation plan

Knowing the level of sedation required is the first step in developing a plan. The aim is to avoid oversedation and use only as much sedative as required. Further consideration of timing and location needs to take place. Can this be deferred until the patient is in a more controlled environment like a hospital? Also, is there a role for non-pharmaceutical interventions, such as distraction?

All of this information will inform the choice of sedative agent. There is no perfect agent, and the choice will be guided by the patient’s needs and the environment. As always, a balance between the benefits (onset of action, duration of action, amnestic qualities, etc.) and the risks (respiratory depression, hypotension, etc.) must be taken into consideration. The effects of most sedative agents are dose dependent; for example, a drug like propofol might provide minimal sedation at 10 mg, but induction of anesthesia at 200 mg.

Table 1: Checklist for procedural sedation: SOAPME [1]

Finally, the term “rescue capacity” (procedural sedation guidelines) recognizes that a patient’s response is unpredictable and emphasizes having equipment and skilled providers available to manage adverse events related to sedation.

An easy start to a backup plan is to ask what is the most likely side effect and what is the worst possible side effect? Have a plan for each. Hypoxia and hypotension are not uncommon and should be anticipated. Catastrophic consequences can often be the result of a lost airway. Assemble any required equipment (suction, oxygen, airway tools, reversal agents, pressors, etc.) and brief team members on the plan before beginning.

Prepare the patient

Preparation will be guided by the patient’s presentation and the purpose of the sedation. Monitoring during sedation is essential, including blood pressure, heart rate and saturation. ETCO₂ used during procedural sedation can recognize impaired respiration earlier than SpO₂ [7].

Can the patient’s condition be optimized before sedation? Pre-oxygenating can delay the onset of hypoxia. Sedation can be performed without IV access, but the degree of risk should dictate the size and number of IVs before beginning the procedure.

Sedation and post-sedation recovery

If the goal is minimal or moderate levels of sedation, I frequently titrate medications, giving repeated small doses until the desired response is achieved. This can help avoid over-sedation. In this context, after the procedure is completed, post-sedation recovery is aimed at mitigating risks such as vomiting, hypotension or hypoxia.

Ongoing sedation, after intubation or in support of ventilation, poses different challenges. The out-of-hospital environment is more dynamic and lacks the equipment and human resources of the ED or ICU. Anecdotally, this results in higher sedation requirements for both patient comfort and maintaining the airway. These factors must be balanced against the evidence that early deep sedation of intubated patients can prolong ICU stays [8]. The solution to this appears to be protocolized sedation. The common themes in most protocols include treating pain before sedation, providing adequate analgesia and sedation before moving to neuromuscular blockers, and the use of sedation scoring systems, such as the Richmond Agitation-Sedation Score (RASS) [6,8].

Special sedation considerations

Certain circumstances may require special considerations. Pregnant women at risk of imminent delivery have sedation complicated by drug effects on the fetus. Agitation related to certain psychiatric conditions may be better treated with agents such as antipsychotics [9].

Excited delirium patients have unique pathology, and complications related to sedation have recently been very public [10]. The specifics of each of these are beyond the scope of this article.

References

1. Coté CJ, Wilson S; AMERICAN ACADEMY OF PEDIATRICS; AMERICAN ACADEMY OF PEDIATRIC DENTISTRY. Guidelines for Monitoring and Management of Pediatric Patients Before, During, and After Sedation for Diagnostic and Therapeutic Procedures. Pediatrics. 2019 Jun;143(6):e20191000. doi: 10.1542/peds.2019-1000. PMID: 31138666
2. Practice Guidelines for Moderate Procedural Sedation and Analgesia 2018: A Report by the American Society of Anesthesiologists Task Force on Moderate Procedural Sedation and Analgesia, the American Association of Oral and Maxillofacial Surgeons, American College of Radiology, American Dental Association, American Society of Dentist Anesthesiologists, and Society of Interventional Radiology. Anesthesiology. 2018 Mar;128(3):437-479. doi: 10.1097/ALN.0000000000002043. PMID: 29334501
3. Procedural Sedation and Analgesia in the Emergency Department: Recommendations for Physician Credentialing, Privileging and Practice O’Connor RE, Sama A, Burton JH, Callaham ML, House HR, Jaquis WP, Tibbles PM, Bromley M, Green SM This article was approved by the ACEP Board of Directors at its June 2011 Board meeting and reflects ACEP’s position on procedural sedation and analgesia in the emergency department.
4. Jarvis JL, Lyng JW, Miller BL, Perlmutter MC, Abraham H, Sahni R. Prehospital Drug Assisted Airway Management: An NAEMSP Position Statement and Resource Document. Prehosp Emerg Care. 2022;26(sup1):42-53. doi: 10.1080/10903127.2021.1990447. PMID: 35001829.
5. Brown LH, Crowe RP, Pepe PE, Miller ML, Watanabe BL, Kordik SS, Wampler DA, Page DI, Fernandez AR, Bourn SS, Myers JB. Adverse events following emergent prehospital sedation of patients with behavioral emergencies: A retrospective cohort study. The Lancet Regional Health-Americas. 2022 May 1;9:100183.
6. Devabhakthuni S, Armahizer MJ, Dasta JF, Kane-Gill SL. Analgosedation: a paradigm shift in intensive care unit sedation practice. Annals of Pharmacotherapy. 2012 Apr;46(4):530-40.
7. Aminiahidashti H, Shafiee S, Kiasari AZ, Sazgar M. Applications of end-tidal carbon dioxide (ETCO2) monitoring in emergency department; a narrative review. Emergency. 2018;6(1).
8. Freeman CL, Evans CS, Barrett TW. Managing sedation in the mechanically ventilated emergency department patient: a clinical review. J Am Coll Emerg Physicians Open. 2020 Apr 10;1(3):263-269. doi: 10.1002/emp2.12045. PMID: 33000041; PMCID: PMC7493591
9. Garriga M, Pacchiarotti I, Kasper S, Zeller SL, Allen MH, Vazquez G, Baldacara L, San L, McAllister-Williams RH, Fountoulakis KN, Courtet P. Assessment and management of agitation in psychiatry: expert consensus. The world journal of biological psychiatry. 2016 Feb 17;17(2):86-128.
10. Linder LM, Ross CA, Weant KA. Ketamine for the acute management of excited delirium and agitation in the prehospital setting. Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy. 2018 Jan;38(1):139-51.