© The authors, 2025

Introduction

Medical emergencies are a rare occurrence in dental practice that all dental practitioners should be prepared for. These can occur in both public and private dental settings. In private dental settings, dental practitioners often utilise calls to emergency services as part of their management [1]. Public dental hospitals differ from private dental practices in that they may have their own internal systems of managing medical emergencies that involve the rapid assessment and management by specially trained staff. One such example is the use of a Medical Emergency Team (MET) call system, which is a rapid response call system that can be triggered by any staff member for a medical emergency. This leads to the immediate assessment by specific emergency response team within the hospital.

MET call systems consist of afferent and efferent limbs. The afferent limb aims to identify acutely unwell or rapidly deteriorating patients who meet the criteria to trigger a call to the efferent limb. Call criteria are usually based on observed abnormalities in vital signs and other clinical observations [2]. The efferent limb comprises of clinicians and nurses with specialised skills in the management of critically unwell patients [3]. MET calls or similar tiered rapid response systems have been implemented across private and public medical hospitals in Australia since the 1990s and have been shown to reduce morbidity and mortality in hospital inpatients [4,5]. They are a national requirement for all medical hospitals in Australia as set out in the National Safety and Quality Healthcare Standard [6]. The use of such MET call systems have also been implemented in public dental hospitals, such as the Royal Dental Hospital of Melbourne, which is the largest public dental facility in the state of Victoria, Australia, that offers a general and emergency dental service, as well as all specialty dental services ranging from oral and maxillofacial surgery to special needs dentistry.

Whilst there is strong evidence for the use of MET calls in medical hospitals, standalone dental hospitals differ from acute medical hospitals in many ways. These include the difference in medical complexity of dental patients, the limited access to dedicated trained medical staff, regular physiological monitoring equipment and access to inpatient hospital beds at dental hospitals. Lack of training and support for clinical staff can lead to the delayed recognition of deteriorating patients and triggering MET calls, which can lead to worsened patient outcomes. Evidence describing the use of MET calls in dental setting is limited, with many emergency guidelines for dental practice recommending dental practitioners to call emergency services instead [7]. Furthermore, evidence regarding the patterns and outcomes of medical emergencies in dentistry in Australia is sparse, particularly within the public sector. This is due to the majority of dental treatment in Australia occurring within the private setting with only 20.3% of dental expenditure being accounted for by public resources such as state and federal governments [8].

The primary aim of this study was to analyse the causes, management, and outcomes of all medical emergency calls made in a large metropolitan dental hospital over an eight-year period. The secondary aim was to determine whether any locations, clinical contexts, types of call or diagnoses were associated with either spontaneous recovery or an increased risk of transfer to a medical hospital.

Methods

At the Royal Dental Hospital of Melbourne, MET calls are made for emergency medical management, with the response team including at least one clinician from the Oral and Maxillofacial Surgery Unit, who is qualified in both medicine and dentistry, and a registered nurse. These are documented contemporaneously by the response team leader using a standardised hospital form.

For this study, records of all MET calls between 1st January 2015 to 1st September 2023 were reviewed retrospectively. Data extracted included date and location of the call, patient demographics including age and gender, medical history, location, type of call, clinical context, primary diagnosis, management, and outcome. The types of call were categorised using the ABCDE primary assessment for emergency resuscitation, which includes emergency calls for Airway, Breathing, Circulation, Disability (or Neurological), Exposure, or other concerns [9]. The clinical context was categorised as pre-treatment, mid-treatment, post-treatment, general anaesthetic, or non-treatment related. Primary diagnoses were categorised into transient loss of consciousness, cardiac, respiratory, gastrointestinal, neurological, psychological, endocrine, odontogenic, and other diagnoses. Management was categorised into no treatment, medications, airway management, dental treatment, and others. Outcomes were categorised into recovery, referral to an outpatient setting, and transfer to a medical hospital. The study was conducted in accordance with the ethical principles outlined in the Declaration of Helsinki and received ethical approval from the Melbourne Dental School Human Ethics Advisory Group, The University of Melbourne (approval number: 1956005) and the Dental Health Services Victoria Research Review Group.

Descriptive statistics were used to analyse variables of interest. Statistical analysis of the data was done using R Studio (version 4.2.1, Posit PBC, Boston, MA). Chi-square tests were used to compare predictor variables and outcome variables. Predictor variables included the location, time, type of call, clinical context, and diagnoses. Outcome variables were spontaneous recovery and transfer to a medical hospital. Results were considered statistically significant if p<0.05.

Results

A total of 156 MET calls were made over the eight-year and eight-month period. Descriptive statistics are shown in Table I. There were 86 females, 54 males and 16 individuals with no recorded sex. The median age was 47 years (IQR: 30 to 62).

The most prevalent location of MET calls was made from the General Dental Unit (39.1%, n = 61). This was followed by the Specialist Dental Units (15.4%, n=24), non-clinical hospital locations (14.7%, n=23), and the Dental Teaching Clinic (13.5%, n=21). There were 13 (8.3%) MET calls that were made for individuals who were located outside the dental hospital, which included individuals who were not patients and presented with an acute medical concern. There were nine MET calls that did not specify a location.

The most common type of emergency call made was for disability-related calls (39.1%, n= 61). These calls include all patients with altered states of consciousness. This was followed by other non-emergency types of calls which included calls related to pain (12.2%, n=19), psychological conditions (12.2%, n=19), and other miscellaneous causes (7.7%, n=12). Airway-related calls accounted for 6.4%(n=10), followed by circulation-related calls at 5.8%(n=9), breathing-related calls at 4.5%(n=7), and exposure-related calls at 4.5%(n= 7).

There were 41 (26.3%) MET calls made for individuals who were awaiting treatment at the dental hospital. There were 27 (17.3%) calls made for individuals who were receiving dental treatment, and 27 (17.3%) calls made for individuals in the post-treatment setting. There were 29 (18.6%) calls made for individuals who were not patients of the dental hospital. These included accompanying friends and family members of patients, staff members, and individuals from outside the hospital needing medical attention. Five MET calls did not specify the clinical context. Only five calls (3.2%) were made for patients undergoing treatment whilst under general anaesthesia.

The most common diagnosis, which accounted for 33.3% of calls (n=52), were those relating to transient losses of consciousness, which included vasovagal syncope, orthostatic hypotension, and seizures. This was followed by cardiovascular presentations which accounted for 16.7%(n=26) of MET calls which included chest pain, arrhythmias, hypotension, and hypertension. Psychological diagnoses made up 12.8% (n=20) of all MET calls, which included anxiety/panic attacks, depression, and delirium. Respiratory diagnoses accounted for 9.0%(n=14) of MET calls which included airway obstructions, oxygen desaturations, asthma attacks, and influenza. There were nine (5.8%) calls each made for gastrointestinal and odontogenic-related diagnoses. Gastrointestinal diagnoses included those related to nausea and abdominal pain. Odontogenic diagnoses included dental abscesses. There were four (2.6%) calls made for hypersensitivity reactions and other neurological diagnoses such as migraines, vertigo, and neuropathic pain. There were two (1.3%) MET calls for endocrine conditions which were related to abnormal blood glucose levels. There were 14 (9.0%) MET calls without a recorded diagnosis.

The majority (64.7%, n=101) of MET calls required no active management. There were 21 (13.5%) MET calls that were managed with medications, which included antibiotics, aspirin, glucose, salbutamol, verapamil, and paracetamol. Airway supportive measures was required for five (3.2%) MET calls, which included intubation with an endotracheal tube, repositioning of the laryngeal mask airway for three general anaesthetic patients, and removal of the rubber dam for another patient mid-treatment. There were four (2.6%) MET calls that were managed with dental treatment, which included tooth extractions or local anaesthetic. There were 24 (15.4%) MET calls that did not specify the management.

61.5% of patients (n=96) made a full recovery, which included those who did not require any tertiary transfer or outpatient referral (55.1%, n=86) and those who made a recovery but received an additional outpatient referral (6.4%, n=10). Referrals were made to services such as oral medicine, oral and maxillofacial surgery, ENT surgery, cardiology, and general medical practitioners. Following this, patients either continued with their dental treatment or were dismissed from their appointments. 25.6% of MET calls (n=40) resulted in the patient requiring a transfer to a tertiary medical hospital for further investigation and management. There was one MET call which resulted in a death over the study period. There were 20 (12.8%) MET calls that did not specify an outcome.

Predictive factors and the outcomes of medical hospital transfer or recovery

Statistical analysis was conducted to examine for any associations between predictor variables and the outcomes of transfer to a tertiary medical hospital or recovery. These are presented in Tables II and III. There was only one statistically significant relationship regarding location, with MET calls that were made from an external location to the dental hospital having a lower chance of spontaneous recovery (RR=0.35, p<0.01). MET calls related to circulation concerns were associated with an increased risk of medical transfer (RR = 3.46, p<0.01), and a decreased risk of spontaneous recovery (RR=0.35, p<.05). Disability related emergency calls were associated with an increased risk of spontaneous recovery (RR=1.32, p<.05).

There were two statistically significant variables related to clinical context. MET calls made for patients who were pre-treatment was associated with an increased chance of spontaneous recovery (RR=1.47, p<0.01). Calls made for those who were not receiving treatment were associated with a lower chance of spontaneous recovery (RR=0.57, p<0.01). Those who had diagnoses falling under transient losses of consciousness or psychological diagnoses had a higher chance of spontaneous recovery (RR=1.49, p<0.01 and RR=1.42, p<0.05, respectively), with psychological diagnoses being also associated with a lower risk of tertiary transfer (RR=0.17, p<0.05). MET calls made for patients with cardiovascular diagnoses were associated with an increased risk of tertiary transfer (RR=3.7, p<0.01) and a lower chance of spontaneous recovery (RR=0.24, p<0.01).

Discussion

The early recognition of medical emergencies within dental practice is a core competency that all dental practitioners should possess. The incidence of such emergencies were rare in this dental hospital with only 156 events over the 104 month period, which equates to 1.5 medical emergencies per month in a facility that provides over 68,000 episodes of general dental care per year. Despite this, the use of a rapid response calling system such as the Medical Emergency Team (MET) call system led to the immediate assessment and response of all medical emergencies within this dental hospital. These rapid response calling systems are a mandatory requirement of all medical hospitals in Australia, but little exists in the literature regarding their use in dental hospitals [6].

Our study aimed to examine medical emergencies in dental practice by assessing the characteristics and outcomes of emergency MET calls made within a public dental hospital. The most common diagnoses were related to transient losses of consciousness (TLOC), which included vasovagal syncope, orthostatic hypotension, and spontaneously resolving seizure events which accounted for 33.3% of all emergency calls. Whilst our findings found that vasovagal syncope was the most common diagnosis, they still only accounted for a third of all presentations, which is lower than other findings in the literature. For example, Oliveira et al. (2010) reported that vasovagal syncope accounted for 59% of emergency presentations, whilst Laurent et al. (2014) reported that it made up of 43.9% of emergencies in dental settings [10,11]. Transient loss of consciousness and psychological diagnoses (which mostly consisted of panic attacks) were also associated with a higher chance of spontaneous recovery (RR = 1.49, p <0.001 and RR = 1.42, p <0.05, respectively).

Our study also found that nearly two thirds (64.7%) of MET calls were managed with no active treatment and most made an uneventful recovery without needing medical transfer, with only one in four (25.6%) emergencies requiring urgent medical transfer. This suggests that the acuity of medical emergencies within dentistry is low, which is supported by similar studies internationally [10–14]. Our findings also indicate that most of these emergencies can be managed adequately within a public dental hospital setting. This is similarly reported by Al-Sebaei (2024) who reported that only 13% of the medical emergencies at a dental hospital in Saudi Arabia required medical transfer [15]. There was one fatality recorded out of the 156 patients who required a MET call over the 8-year and 8-month period. This individual was not a patient of the hospital, was located external to the hospital and was found deceased upon initial review, which suggests an acute unidentified medical episode unrelated to dental treatment as their cause of death. They were subsequently transferred to a medical hospital. This is comparable to death rates in general dental practice with Atherton et al. (1999) reporting on only 20 deaths out of 2,923 (0.68%) medical emergencies over a ten-year period of Great Britain [16]. Death rates from MET calls in medical hospitals tends to be much higher due to the increased morbidity of medical patients, with Buist et al. (2007) reporting that deaths occurred in 22% of MET calls made in an Australian metropolitan medical hospital in 2005 [17].

This difference in MET call outcomes between dental and medical hospitals is likely due to the differences in the health and medical fitness of patients who attend outpatient based dental hospitals compared with those attending acute inpatient medical hospitals. Public dental patients when compared to public medical patients tend to be more medically fit as their reasons for presentation are due to oral diseases as opposed to acute medical issues [18–21]. Common oral diseases that cause patients to present to dental hospitals such as dental caries, pulpitis and periodontitis, are less likely to be life threatening compared to the myriad of acute medical problems that a patient in a medical hospital may present with. As a result, when comparing medical emergencies between dental and medical hospitals, those that occur at dental hospitals tend to be of a lower severity and therefore morbidity than those that occur in medical hospitals [22–24].

When examining the emergency criteria for triggering MET calls, we found that 60.3% (n= 94) of MET calls made at the dental hospital were able to be categorised within the ABCDE emergency assessment criteria of Airway, Breathing, Circulation, Disability, and Exposure causes for a critically ill or deteriorating patient. This suggests that many of these calls were made for concerns that were not immediately life threatening or not adequately captured by the ABCDE framework. Of the type of emergency calls that were categorised within the ABCDE criteria, calls regarding circulation problems were at an increased risk of requiring urgent medical transfer (RR=3.46, p<0.01) with a lower chance of recovery (RR=0.35, p <0.05). Circulation related calls consisted of hypotensive or hypertensive events and arrhythmias. Cardiovascular-related diagnoses, which included patients who presented with acute chest pain, were also at a much higher risk of requiring medical transfer (RR=3.7, p <0.01). Both these findings suggest that the threshold for urgent medical transfer is low for suspected acute coronary events and haemodynamic instabilities within the dental setting. We believe this to be an appropriate response given that acute coronary syndromes are a major cause of premature death in adults with a significant mortality rate of nearly 25% in those occurring in non-medical hospital settings [25].

There were 35.2% of MET calls made for reasons that did not fall within the ABCDE emergency assessment criteria, with a significant proportion of non-urgent calls that were made for patients who were not medically deteriorating, such as those suffering from anxiety attacks. This may be explained by the fact that the dental hospital in our study consists mostly of dentally trained staff and non-clinical staff who are also not medically trained. Further training in advanced life support may be helpful for staff to assess the key criteria of a clinically deteriorating patient.

The rate of MET calls made for patients who were undergoing general anaesthesia (GA) was extremely low in our study, with only five calls made over the nine-year period. This extremely low incidence of anaesthesia MET calls is similarly reported in the literature with Aiudi et al. (2021) reporting that only 0.16% of anaesthetic cases required an emergency call [26]. This is may be explained by anaesthetists potentially having a much higher threshold to make a MET call given their greater training in critical care medicine, including resuscitation and crisis management [27]. The other potential reason is that the pre-selection criteria for patients undergoing GA at our facility is strict and only allows for patients who have minimal medical comorbidities. This is because this dental hospital does not have access to an intensive care unit (ICU) or an overnight stay facility, which limits the acceptable risk of GA procedures for patients. For example, patients who have active cardiac disease, airway issues, bleeding disorders, poorly controlled diabetes, chronic kidney disease on renal dialysis, or those who require an overnight stay do not meet the criteria for GA. These conditions have been known to significantly increase the risk of a general anaesthetic and helps to explain the low rate of MET calls made under GA [26].

Interestingly, the most common clinical context for MET calls were for patients awaiting dental treatment, with over one in four (26.3%, n=41) MET calls arising from these situations. This combined with the finding that nearly half were diagnosed with a panic attack or a TLOC, which included vasovagal syncope. This suggests that dental anxiety may play a significant role in emergencies in dental practice. This is likely due to vasovagal syncope having a significant psychological component which can be triggered by stress and anxiety [28,29]. Dental patients are often highly anxious before receiving care, with Armfield (2010) reporting that the prevalence of high dental fear in Australia ranged between 7.8% to 18.8% [30]. Further education and training in the management of dental fear and anxiety via the use of relaxation techniques may provide useful for all dental practitioners given the frequency of dental anxiety within the population.

Even though most of the MET calls at the dental hospital were not life threatening, the threshold for immediate tertiary transfer should remain low, given the potential for life threatening medical emergencies that can occur in any setting. It is therefore imperative that all dental clinicians including auxiliary staff are adequately trained on the recognition and initial management of medical emergencies in a dental setting. This framework ensures that all clinicians have a standardised and systematic approach to be able to assess and perform some basic but essential life saving measures for any medical emergency they encounter. Regular training and renewal of life saving skills for all dental staff is recommended by several governing bodies in Australia including the Australian Resuscitation Council which recommends that first aid skills should be renewed every three years and cardiopulmonary resuscitation (CPR) should be renewed yearly [31]. The Australian Therapeutic Guidelines also recommends that all dental settings, both hospital and private practice, should have a basic first aid kit that includes essential medications and equipment that are commonly used in medical emergencies, and that clinicians are well versed in their use and indications [32].

One limitation of the study was the reliance on retrospective data that had some incomplete entries. This is likely due to the heterogeneity in clinicians who completed the MET call forms as part of the emergency response team over the nearly nine-year period. This limitation should therefore be considered when interpreting the findings as they may be impacted by the missing data and the differences in the diagnosis and management of medical emergencies that may occur between emergency response teams. Despite this, we believe that our study is one of the few to examine the characteristics of emergency medical calls within a public dental hospital, particularly within Australia. Whilst the severity of such emergencies was generally lower when compared with medical hospitals, the potential for rapid deterioration still exists within a dental hospital setting. This highlights the importance of rapid medical assessment and emergency management by all dental practitioners.

Conclusion

Medical emergencies within a public dental hospital are generally low in medical severity. Emergency calls were most likely to be made for concerns over disability, with transient losses of consciousness such as vasovagal syncope, being the most common diagnosis. Nearly two thirds of emergency calls did not require any active management and only one in four emergencies required an urgent medical transfer. Calls made for patients with a concern over circulation or a cardiovascular diagnosis are more likely to require transfer to a tertiary medical hospital.

Funding

The authors received no financial support for the research, authorship, and publication of this article.

Conflicts of interest

The authors do not have any conflicts of interest to disclose.

Data availability statement

The dataset generated during and analysed during this study are available from the corresponding author on reasonable request.

Author contribution statement

Vincent Tran: Methodology, Data Curation, Formal Analysis, Writing – Original Draft, Writing – Review & Editing. Mustafa Mian: Conceptualisation, Writing – Review & Editing. Arya Rao: Investigation. Leila Chye: Investigation. Seth Delpachitra: Writing Review & Editing, Supervision. Krati Garg: Writing – Review & Editing, Supervision.

Ethics approval

The study was conducted in accordance with the ethical principles outlined in the Declaration of Helsinki and received ethical approval from the Melbourne Dental School Human Ethics Advisory Group, The University of Melbourne (approval number: 1956005) and the Dental Health Services Victoria Research Review Group.

References

All Tables