What’s the chance that a patient faints in my office? Studies have shown that syncope, or fainting, is the most common medical emergency at the dental office.1 The next most common medical emergencies include hyperventilation, mild allergic responses, angina, and hypoglycemia. One meta-analysis showed that dentists experienced an average of 1.2 cases of syncope per year.2 So how competent are dentists at managing syncope? Surveys suggest that somewhere between 54-77% of dentists judged themselves capable to diagnose and manage a syncopal episode.3 Hopefully, this guide will help to improve our teams’ effective management of syncopal episodes in the future.
Syncope is a temporary loss of consciousness as a result of reduced cerebral perfusion, typically caused by a vasovagal hypotensive response. In the dental office, anxiety, fear, and stress all contribute to this reaction. Leading up to a loss of consciousness, patients report experiencing presyncopal symptoms, including feeling dizzy, light-headed, warm, sweaty, cold, nauseous, weak, and/or experiencing visual/auditory disturbances. Bradycardia and hypotension may also be seen during presyncope and syncope.
As in any medical emergency for unconscious victims, the initial sequence begins with CAB (Circulation, Airway, Breathing). Table 1 outlines the initial patient assessment.
Table 1: Simple algorithm for assessing an unconscious patient’s circulation, airway, and breathing when syncope is suspected.
| CAB Sequence | |
| Circulation | Is there a pulse? Is their capillary refill time delayed? Are they pale? Are they cold? |
| Airway | Is the airway patent? Are they speaking? Are all secretions and foreign bodies removed? Are they able to maintain their own airway? |
| Breathing | Are they breathing spontaneously? Can you see chest rise and fall? Do you see misting in the oxygen mask? Can you auscultate bilateral air entry in the lungs? |
For the patient who has a pulse and is breathing spontaneously the treatment algorithm is as follows:
- Recognize syncope
- Discontinue treatment
- Call for help
- Place patient in Trendelenburg position (head down, feet up) position
- Administer 100% O2
- Place a cold towel on the forehead
- Blood glucose test – consider giving an oral carbohydrate (juice box) if conscious
- Call 911 if interventions fail or the patient’s condition worsens
- Recovery: vital signs back to baseline and good patient alertness
It is important to consider other possible diagnoses besides syncope. Other differential diagnoses to consider for an unconscious patient include:
- Seizure
- Hypoglycemia
- Drug overdose
- Orthostatic hypotension
- Myocardial infarction
- Cardiac arrest
Though most patients who experience syncope recover quickly and fully, a prolonged period of reduced cerebral perfusion can lead to greater morbidity and even mortality, making prompt and effective treatment essential. The threshold to call 911 should be low, especially if there is any amount of doubt or uncertainty.
Preventing syncope is difficult. It is generally thought that the extremely anxious and hypoglycemic patient is more prone to syncope with interventions like local anesthetic injections. Managing patient anxiety and ensuring patients are not hypoglycemic will reduce the probability of syncope. Nevertheless, any patient can experience syncope, and dentists must be confident and prepared to deal with this situation, including knowing when to call for help. 
Oral Health welcomes this original article.
References
- Haas DA. Management of Medical Emergencies in the Dental Office: Conditions in Each Country, the Extent of Treatment by the Dentist. Anesth Prog. 2006; 53(1): 20–4.
- Hutse I, Coppens M, Herbelet S, Seyssens L, Marks L. Syncope in Dental Practices: A Systematic Review on Aetiology and Management. Journal of Evidence Based Dental Practice. 2021 Sep 1; 21(3): 101581.
- Arsati F, Montalli VA, Flório FM, Ramacciato JC, da Cunha FL, Cecanho R, et al. Brazilian dentists’ attitudes about medical emergencies during dental treatment. J Dent Educ. 2010 Jun; 74(6): 661–6.
About the author
Dr. Darrien Lui, a first-year postgraduate resident in Dental Anaesthesia at the University of Toronto.