Swimming-Induced Pulmonary Edema: Evaluation of Prehospital Treatment With CPAP or Positive Expiratory Pressure Device.

BACKGROUND: Swimming-induced pulmonary edema (SIPE) occasionally occurs during swimming in cold open water. Although optimal treatment for SIPE is unknown, non-invasive positive pressure ventilation (NPPV) is an option for prehospital treatment. RESEARCH QUESTION: Is NPPV a feasible and safe prehospital treatment for SIPE, and which outcome measures reflect recovery after treatment? STUDY DESIGN AND METHODS: A prospective observational study was conducted at Vansbrosimningen, Sweden's largest open water swimming event, from 2017 through 2019. Swimmers with a diagnosis of SIPE and with peripheral oxygen saturation (Spo2) of ≤ 95%, persistent respiratory symptoms, or both were eligible for the study. NPPV was administered on site as CPAP by facial mask or as positive expiratory pressure (PEP) by a PEP device. Discharge criteria were Spo2 of > 95% and clinical recovery. Four outcome measures were evaluated: Spo2, crackles on pulmonary auscultation, pulmonary edema on lung ultrasound (LUS), and patient-reported respiratory symptoms. RESULTS: Of 119 treated individuals, 94 received CPAP, 24 received treatment with a PEP device, and one required tracheal intubation. In total, 108 individuals (91%) were discharged after NPPV for a median of 10 to 20 min and 11 individuals (9%) required hospital transfer. NPPV resulted in increased Spo2 from a median of 91% to 97% (P < .0001) together with improvement of six patient-reported respiratory symptoms (median numerical rating scales, 1-7 to 0-1; P < .0001). No significant decrease in auscultation of crackles (93% vs 87%; P = .508) or pulmonary edema on LUS (100% vs 97%; P = .500) was seen during NPPV treatment. INTERPRETATION: NPPV administered as CPAP or via a PEP device proved feasible and safe as prehospital treatment for SIPE with a vast majority of patients discharged on site. Spo2 and patient-reported respiratory symptoms reflected recovery after treatment, whereas pulmonary auscultation or LUS findings did not.

Lung Ultrasound for Identification of Patients Requiring Invasive Mechanical Ventilation in COVID-19.

OBJECTIVES: Indication for invasive mechanical ventilation in COVID-19 pneumonia has been a major challenge. This study aimed to evaluate if lung ultrasound (LUS) can assist identification of requirement of invasive mechanical ventilation in moderate to severe COVID-19 pneumonia. MATERIALS AND METHODS: Between April 23 and November 12, 2020, hospitalized patients with moderate to severe COVID-19 (oxygen demand ≥4 L/min) were included consecutively. Lung ultrasound was performed daily until invasive mechanical ventilation (IMV-group) or spontaneous recovery (non-IMV-group). Clinical parameters and lung ultrasound findings were compared between groups, at intubation (IMV-group) and highest oxygen demand (non-IMV-group). A reference group with oxygen demand <4 L/min was examined at hospital admission. RESULTS: Altogether 72 patients were included: 50 study patients (IMV-group, n = 23; non-IMV-group, n = 27) and 22 reference patients. LUS-score correlated to oxygen demand (SpO2 /FiO2 -ratio) (r = 0.728; p < .0001) and was higher in the IMV-group compared to the non-IMV-group (20.0 versus 18.0; p = .026). Based on receiver operating characteristic analysis, a LUS-score of 19.5 was identified as cut-off for requirement of invasive mechanical ventilation (area under the curve 0.68; sensitivity 56%, specificity 74%). In 6 patients, LUS identified critical coexisting conditions. Respiratory rate and oxygenation index ((SpO2 /FiO2 )/respiratory rate) ≥4.88 identified no requirement of invasive mechanical ventilation with a positive predictive value of 87% and negative predictive value of 100%. CONCLUSIONS: LUS-score had only a moderate diagnostic value for requirement of invasive mechanical ventilation in moderate to severe COVID-19. However, LUS proved valuable as complement to respiratory parameters in guidance of disease severity and identifying critical coexisting conditions.

Swimming-Induced Pulmonary Edema: Diagnostic Criteria Validated by Lung Ultrasound.

BACKGROUND: Despite the increasing popularity of open water swimming worldwide, swimming-induced pulmonary edema (SIPE) is a poorly recognized condition lacking established diagnostic criteria. RESEARCH QUESTION: The aim of this study was to identify diagnostic criteria of SIPE during a large open water swimming event. STUDY DESIGN AND METHODS: In this cross-sectional study, 17,904 individuals swam 1,000, 1,500, or 3,000 m in cold open water during Sweden's largest open water swimming event in 2018 and 2019. Of 166 swimmers seeking medical attention for acute respiratory symptoms, 160 were included in the study. Medical history, symptoms, and clinical findings were collected. On-site lung ultrasound (LUS) was performed to verify pulmonary edema. RESULTS: Pulmonary edema was confirmed by LUS in 102 patients (64%); findings were unilateral in 11 (7%). Peripheral oxygen saturation was identified as a strong independent diagnostic test for pulmonary edema, with ≤ 95% as the suggested cut off based on receiver-operating characteristic curve analysis (area under the curve, 0.893; P < .0001). Crackles on lung auscultation, predominantly over the anterior chest, identified 88% of patients with edema. Peripheral oxygen saturation ≤ 95% or auscultation findings of crackles identified pulmonary edema with a sensitivity of 97% and a specificity of 86%. A specificity of 98% and a positive predictive value of 99% for LUS-verified pulmonary edema were reached if patients presented with both oxygen saturation ≤ 95% and auscultation of crackles. INTERPRETATION: We suggest a clinical algorithm for diagnosis of SIPE for swimmers with acute respiratory symptoms during swimming in cold open water. Novel features of focally distributed edema in the anterior parts of the lungs, sometimes unilateral, add to this unique dataset of an underreported condition.

Checklists in pre-hospital advanced airway management.

BACKGROUND: In pre-hospital care, pre-intubation checklists (PICL) are widely implemented as a safety measure and guidelines support their use. However, the true value of PICL among experienced airway providers is unknown. This study aims to explore possible benefits and disadvantages of PICL in the pre-hospital setting. METHODS: We performed a subgroup analysis of a prospective, observational, multicentre study on pre-hospital advanced airway management in the Nordic countries between May 2015 and November 2016. The original trial was designed to investigate the success rates of pre-hospital tracheal intubations and the incidence of complications. Our study limited inclusion to drug assisted intubations performed by anaesthesiologists. Intubation success rates and complication rates were plotted against checklist use. RESULTS: We analyzed 588 pre-hospital intubations for medical and traumatic emergencies. Overall, checklists were used in 60.5% of instances. Applying checklists was associated with increased success at first and second intubation attempts. There was no significant difference in the overall success rates (99.4% and 99.1%). Oesophageal misplacement was more common in the No-PICL group (2.2% vs 0.3%) but otherwise the incidence of airway related complications did not differ between the groups. Scene time was significantly shorter in the No-PICL group (23.6 vs 27.5 minutes). CONCLUSION: In this retrospective study, checklist use correlated with fewer attempts at intubation when securing the airway. Despite this, we found no association between checklist use and the overall TI success rate or the incidence of serious adverse events. Scene times were shorter without PICL.

The mission characteristics of a newly implemented rural helicopter emergency medical service.

BACKGROUND: Physician-staffed helicopter emergency services (HEMS) can provide benefit through the delivery of specialist competence and equipment to the prehospital scene and through expedient transport of critically ill patients to specialist care. This paper describes the integration of such a system in a rural Swedish county. METHODS: This is a retrospective database study recording the outcomes of every emergency call centre dispatch request as well as the clinical and operational data from all completed missions during this service's first year in operation. RESULTS: During the study period, HEMS completed 478 missions out of which 405 (84,7%) were primary missions to prehospital settings and 73 (15,3%) were inter-hospital critical care transfers. A majority (55,3%) of primary missions occurred in the regions furthest from our hospitals, in municipalities housing only 15,6% of the county's population. The NACA (IQR) score on primary and secondary missions was 4 (2) and 5 (1), respectively. CONCLUSIONS: This study describes the successful integration of a physician-based air ambulance service in a Scandinavian rural region. Municipalities distant from our hospitals benefitted as they now have access to early specialist intervention and expedient transport to critical hospital care. Our hospitals and most populated areas benefitted from HEMS secondary mission capability as they gained a dedicated ICU transport service that could provide specialist intensive care during rapid inter-hospital transfer.