Characteristics and critical care interventions in drowning patients treated by the Danish Air Ambulance from 2016 to 2021: a nationwide registry-based study with 30-day follow-up.

BACKGROUND: Improving oxygenation and ventilation in drowning patients early in the field is critical and may be lifesaving. The critical care interventions performed by physicians in drowning management are poorly described. The aim was to describe patient characteristics and critical care interventions with 30-day mortality as the primary outcome in drowning patients treated by the Danish Air Ambulance. METHODS: This retrospective cohort study with 30-day follow-up identified drowning patients treated by the Danish Air Ambulance from January 1, 2016, through December 31, 2021. Drowning patients were identified using a text-search algorithm (Danish Drowning Formula) followed by manual review and validation. Operational and medical data were extracted from the Danish Air Ambulance database. Descriptive analyses were performed comparing non-fatal and fatal drowning incidents with 30-day mortality as the primary outcome. RESULTS: Of 16,841 dispatches resulting in a patient encounter in the six years, the Danish Drowning Formula identified 138 potential drowning patients. After manual validation, 98 drowning patients were included in the analyses, and 82 completed 30-day follow-up. The prehospital and 30-day mortality rates were 33% and 67%, respectively. The National Advisory Committee for Aeronautics severity scores from 4 to 7, indicating a critical emergency, were observed in 90% of the total population. They were significantly higher in the fatal versus non-fatal group (p < 0.01). At least one critical care intervention was performed in 68% of all drowning patients, with endotracheal intubation (60%), use of an automated chest compression device (39%), and intraosseous cannulation (38%) as the most frequently performed interventions. More interventions were generally performed in the fatal group (p = 0.01), including intraosseous cannulation and automated chest compressions. CONCLUSIONS: The Danish Air Ambulance rarely treated drowning patients, but those treated were severely ill, with a 30-day mortality rate of 67% and frequently required critical care interventions. The most frequent interventions were endotracheal intubation, automated chest compressions, and intraosseous cannulation.

Dispatcher Stroke/TIA Recognition in Emergency Medical Call Center and Out-of-Hours Service Calls in Copenhagen, Denmark.

Background and Objectives: Recognition of stroke/TIA symptoms by emergency medical services (EMS) is instrumental in providing timely recanalization treatments. We assessed the recognition of stroke/TIA by EMS via the emergency medical call center (EMCC) dispatchers and out-of-hours health service (OOHS) dispatchers. Methods: In a registry study, based on 2015-2020 data from the Copenhagen EMS, we calculated sensitivity, positive predictive value (PPV), specificity, and negative predictive value (NPV) of dispatcher suspicion of stroke or transient ischemic attack (TIA) and compared against discharge diagnosis. Results: We included 462,029 contacts to EMCC and 2,573,865 contacts to OOHS. In total, 19,798 contacts had a stroke or TIA diagnosis at hospital discharge. Sensitivity was 0.64 for EMCC dispatchers and 0.25 for OOHS. PPV was 0.28 for EMCC and 0.22 for OOHS; specificity was 0.96 for EMCC and >0.99 for OOHS, and NPV was 0.99 for EMCC and >0.99 for OOHS. Sensitivity improved over the period of the study from 0.62 to 0.68 for EMCC and from 0.20 to 0.25 for OOHS. PPV did not change over the period for EMCC and decreased from 0.26 to 0.19 for OOHS. Both EMCC and OOHS more frequently overlooked stroke in women, in patients calling more than 3 hours after symptom onset, and for more severe strokes. For OHHS, advanced age correlated with lower recognition. Discussion: As the first study reporting on OOHS setting dispatcher stroke/TIA recognition, we find a need for the improvement of stroke/TIA recognition both in EMCC and in OOHS. Solutions may include specific training of dispatchers, public awareness campaigns, and new technological solutions.

Danish Drowning Formula for identification of out-of-hospital cardiac arrest from drowning.

BACKGROUND: Accurate, reliable, and sufficient data is required to reduce the burden of drowning by targeting preventive measures and improving treatment. Today's drowning statistics are informed by various methods sometimes based on data sources with questionable reliability. These methods are likely responsible for a systematic and significant underreporting of drowning. This study's aim was to assess the 30-day survival of patients with out-of-hospital cardiac arrest (OHCA) identified in the Danish Cardiac Arrest Registry (DCAR) after applying the Danish Drowning Formula. METHODS: This nationwide, cohort, registry-based study with 30-day follow-up used the Danish Drowning Formula to identify drowning-related OHCA with a resuscitation attempt from the DCAR from January 1st, 2016, through December 31st, 2021. The Danish Drowning Formula is a text-search algorithm constructed for this study based on trigger-words identified from the prehospital medical records of validated drowning cases. The primary outcome was 30-day survival from OHCA. Data were analyzed using multiple logistic regression. RESULTS: Drowning-related OHCA occurred in 374 (1%) patients registered in the DCAR compared to 29,882 patients with OHCA from other causes. Drowning-related OHCA more frequently occurred at a public location (87% vs 25%, p < 0.001) and were more frequently witnessed by bystanders (80% vs 55%, p < 0.001). Both 30-day and 1-year survival for patients with drowning-related OHCA were significantly higher compared to OHCA from other causes (33% vs 14% and 32% vs 13%, respectively, p < 0.001). The adjusted odds ratio for 30-day survival for drowning-related OHCA and other causes of OHCA was 2.3 [1.7-3.2], p < 0.001. Increased 30-day survival was observed for drowning-related OHCA occurring at swimming pools compared to public location OHCA from other causes with an OR of 11.6 [6.0-22.6], p < 0.001. CONCLUSIONS: This study found higher 30-day survival among drowning-related OHCA compared to OHCA from other causes. This study proposed that a text-search algorithm (Danish Drowning Formula) could explore unstructured text fields to identify drowning persons. This method may present a low-resource solution to inform the drowning statistics in the future. REGISTRATION: This study was registered at ClinicalTrials.gov before analyses (NCT05323097).