Serious conditions in patients presenting with non-specific chief complaints to the Emergency medical service (EMS)

Abstract

BACKGROUND: Ambulance clinicians encounter patients presenting with non-specific chief complaints on a daily basis. Such complaints can also be described as “decreased general health condition” “general malaise” and “sense of sickness”. These symptoms are often accompanied by vital signs within the normal reference range. It is known that one in three patients in the emergency department presenting with non-specific chief complaints have underlying serious conditions. In the context of ambulance care, there is a lack of knowledge in the group of patients and the identification of serious conditions within that group.

AIM: The overall aim was for patients with non-specific complaints in the pre-hospital setting; to describe the population for both those who are transported to hospitals or not i.e., conveyed, or non-conveyed, to investigate whether biomarkers can contribute to the identification of those who develop a serious condition, and to describe the experiences of pre-hospital emergency nurses in caring for the patient.

METHODS: Four sub-studies were performed. Study I was a retrospective, population-based study with the aim to describe the population and establish the prevalence of serious conditions as well as mortality rates among patients presenting with non-specific chief complaints and who were transported to the ED. Patients were identified via the electronic ambulance medical records (CAK-net, Region Stockholm) and data was retrieved from the National Patient Register and Causes of death register at Sweden’s National Board of Health and Welfare. Descriptive statistics was performed. Study II was a retrospective, population-based study with the aim to describe the population, establish the prevalence of serious condition as well as mortality rates and to compare between the groups of patients who were conveyed or non-conveyed. Descriptive statistics and regression analysis was performed. Study III was a qualitative interview study of prehospital emergency nurses experiences in caring for patients presenting with non-specific chief complaints. Qualitative content analysis according to Elo and Kyng s was performed. Study IV was a prospective, double-blind, multicenter study with the aim to determine if the biomarkers suPAR and lactate could identify serious conditions, as well as the predictive value on mortality. Ambulance care systems from Stockholm Region and two regions of Helsinki, Finland participated. Two blood tests were drawn after index ambulance assessment. Descriptive statistics as well as regression and likelihood analyses were performed.

RESULT: In Study I, 3780 patients were included and had a median age of 77 years. Serious condition was prevalent in 35.3%. Admittance to hospital care was 67.7%. Patients with prevalent serious conditions had 20.2% 30-day mortality compared to 4.2% in the group without serious conditions. The majority of the patients had low triage scores according to Rapid Emergency Triage and Treatment System (RETTS) (60.7%) and National Early Warning Score (NEWS) (76.3%) and 23.9% and 28.3% had prevalent serious conditions respectively. 30-day mortality was 13.0% and 14.1% respectively. In Study II, a total of 4744 patients were included, with a median age of 76 years. A serious condition was present in 29.5% of the patients. Among those who were non-conveyed, serious conditions was present in 6.6% compared to 35.3% among those conveyed. 30-day mortality was 17.2% for those with prevalent serious conditions and who were non-conveyed, compared to 20.2% in the group who were conveyed. In Study III the prehospital emergency nurses expressed that an indepth systematic assessment may reduce suffering and increase patient safety. The systematic assessment is based on acknowledging the unexplained suffering, a systematic approach and experience, and that organizational processes such as feedback on given care are key for a meaningful caring encounter and optimal assessment. In Study IV, a total of 414 patients were included. The median age was 82 years of age. 15.2% of the patients had a serious condition. A positive likelihood ratio (LR+) of 1.17 and a positive predictive value (PPV) of 17.3% as being predictive of a serious condition was observed when suPAR was elevated above 3 ng/ml. A LR+ of 4.67 and a PPV of 16.7% was observed for suPAR levels above 9 ng/ml as being predictive of 30-day mortality. Lactate was not significantly predictive.

CONCLUSIONS: Several conclusions stem from the findings in the four sub-studies. The results indicate that the identification of serious conditions among patients presenting with non-specific chief complaints to the ambulance service is still complicated. Serious conditions are present in both high and low triage levels. These triage systems are based on vital signs and may therefore be insufficient tools with which to identify serious conditions. The patients who are non-conveyed after index assessment do not differ from the patients conveyed in term of symptoms, sex or age. However, they differ in terms of prevalence of serious conditions and mortality, which is in both cases lower. The biomarkers, suPAR and lactate cannot differentiate between patients with or without serious conditions, but the association with mortality could add value to the clinical assessment. Prehospital emergency nurses experience that this patient group benefits from an in-depth systematic assessment that can reduce suffering and increase patient safety, and that organizational factors such as feedback and differentiated levels of care could have positive effects on care in general and for patients with non-specific chief complaints in particular. The results indicate that the assessments are complex and that the objective parameters used are not sufficient to identify serious conditions. Identification of serious conditions among patients presenting with NSCs to the ambulance service remains a challenge. Increased education and feedback on given care would likely increase the identification. However, an enhanced understanding of the atypical presentations of NSCs and the process of clinical reasoning could strengthen the ACs in performing person-centered care.