Clinical presentation of tension pneumothorax among patients undergoing prehospital thoracostomy: A retrospective cohort study.

Background: Tension pneumothorax (TPTX) is a life-threatening condition requiring rapid diagnosis and management. However, accurate diagnosis is challenging in the prehospital environment. We sought to investigate the clinical presentation of TPTX in the prehospital environment. Secondary objectives were to investigate if any vital signs are independently associated with TPTX, and if any differences in vital signs of TPTX exist between patients based on ventilatory status.

Methods: We conducted a retrospective cohort study of adult patients > 18 years of age, not in cardiac arrest, who received thoracostomy from paramedics in Ambulance Victoria between January 2020 and July 2023. Descriptive characteristics, vital signs and management data were collected. Patients were defined as having had a TPTX if they met a published definition criterion of TPTX. A secondary sub-group sample was created by dividing patients in the TPTX group based on their ventilatory status at the time of thoracostomy (positive pressure ventilated [PPV] or spontaneously ventilating [SV]). Descriptive statistics, univariate analysis and multivariate analysis via logistic regression were performed.

Results: A total of 361 patients were included, with 179 (49.6 %) of these patients meeting the definition criteria of TPTX. Out of these, 67 were receiving PPV and 112 were SV. The median age of patients with TPTX was 44 years, most (79 %) were male, most occurred secondary to trauma (91.6 %). Out of patients with TPTX, 98 (87.5 %) had an altered conscious state, 128 (71.5 %) were tachycardic, 75 (41.9 %) were hypotensive, 33 (18.4 %) had an unrecordable blood pressure, 97 (54.2 %) had hypoxemia, and 82 (73.2 %) were tachypneic. Hypotension (aOR 2.04; 95 % CI 1.09-3.79; p = 0.025) and hypoxemia (aOR 2.12; 95 % CI 1.18-3.81; p = 0.011) were independently associated with the presence of TPTX in multivariate analysis. When comparing vital signs between SV and PPV patients with TPTX, no vital signs reached a statistically significant difference in multivariate analysis.

Conclusion: The presence of hypoxemia and hypotension were independently associated with the presence of TPTX. Vital signs associated with the presence of TPTX did not differ by ventilatory status of the patient. Future research should report on conscious state assessment and respiratory rate when investigating the clinical presentation of TPTX.