Clinical spectrum and risk factors for mortality among seawater and freshwater critically ill drowning patients: a French multicenter study

Development and validation of a clinico-biological score to predict outcomes in patients with drowning-associated cardiac arrest

BACKGROUND

While several scoring systems have been developed to predict short-term outcome in out-of-hospital cardiac arrest patients, there is currently no dedicated prognostic tool for drowning-associated cardiac arrest (DACA) patients.

METHODS

Patients experiencing DACA from two retrospective multicenter cohorts of drowning patients were included in the present study. Among the patients from the development cohort, risk-factors for day-28 mortality were assessed by logistic regression. A prediction score was conceived and assessed in patients from the validation cohort.

RESULTS

Among the 103 included patients from the development cohort, the day-28 mortality rate reached 51% (53/103). Identified independent early risk-factors for day-28 mortality included cardiopulmonary resuscitation duration longer than 20 min (OR 6.40 [95% CI 1.88-23.32]; p = 0.003), temperature at Intensive Care Unit admission <34 °C (OR 8.84 [95% CI 2.66-32.92]; p < 0.001), need for invasive mechanical ventilation (OR 6.83 [95% CI 1.47-40.87]; p = 0.02) and lactate concentration > 7 mmol/L (OR 3.56 [95% CI 1.01-13.07]; p = 0.04). The Area Under the ROC Curve (AUC) of the developed score based on those variables reached 0.91 (95% CI, 0.86-0.97). The optimal cut-off for predicting poor outcomes was 4 points with a sensitivity of 92% (95% CI, 82-98%), a specificity of 82% (95% CI, 67-91%), a positive predictive value (PPV) of 84% (95% CI, 72-95%) and a negative predictive value (NPV) of 91% (95% CI, 79-96%). The assessment of this score on the validation cohort of 81 patients exhibited an AUC of 0.82. Using the same 4 points threshold, sensitivity, specificity, PPV and NPV values of the validation cohort were: 81%, 67%, 72% and 77%, respectively.

CONCLUSION

In patients suffering from drowning induced initial cardiac arrest admitted to ICU with a DACA score ≥ 4, the likelihood of survival at day-28 is significantly lower. Prospective validation of the DACA score and assessment of its usefulness are warranted in the future.

MicroRNA‑200c‑3p regulates seawater‑induced acute lung injury via ANGII and ACE2/ANG1‑7 pathways

Apoptosis is a main characteristic of seawater aspiration-induced acute lung injury (ALI). The local angiotensin (ANG) system angiotensin converting enzyme (ACE)-2/ANG1-7/Mas axis and ANGII/angiotensin II receptor type 1 (AT1) play an important role in apoptosis. MicroRNA (miR)-200c-3p is involved in the regulation of the ACE-2 pathway, but its role and mechanism in seawater-induced ALI remain to be elucidated. In the present study, seawater-ALI lung tissue and cell model was established and apoptosis-related proteins, ACE2, ANGII, ANG1-7 were detected by western blotting following downregulation of miR-200c-3p. In addition, miR-200c-3p was detected by reverse transcription-quantitative PCR. The target relationship between miR-200c-3p and ACE2 was confirmed by dual-luciferase reporter assay. Seawater stimulation increased the expression of miR-200c-3p, ANGII and decreased ACE-2/ANG1-7 expression and induced changes of apoptosis-related protein expression. Apoptosis can be inhibited by AT1 blocker and abrogated by addition of ANG1-7 following seawater stimulation. In addition, inhibition of miR-200c-3p suppressed apoptosis and decreased the expression of ANGII, but increased the ACE-2/ANG1-7 expression. These results suggested that increased expression of miR-200c-3p was an important cause in seawater-induced ALI and this phenomenon was through inhibition of ACE2/ANG1-7 pathway.

Termination of Cardiopulmonary Resuscitation in Mountain Rescue: A Scoping Review and ICAR MedCom 2023 Recommendations

Lugnet, Viktor, Miles McDonough, Les Gordon, Mercedes Galindez, Nicolas Mena Reyes, Alison Sheets, Ken Zafren, and Peter Paal. Termination of cardiopulmonary resuscitation in mountain rescue: a scoping review and ICAR MedCom 2023 recommendations. High Alt Med Biol. 24:274-286, 2023. Background: In 2012, the International Commission for Mountain Emergency Medicine (ICAR MedCom) published recommendations for termination of cardiopulmonary resuscitation (CPR) in mountain rescue. New developments have necessitated an update. This is the 2023 update for termination of CPR in mountain rescue. Methods: For this scoping review, we searched the PubMed and Cochrane libraries, updated the recommendations, and obtained consensus approval within the writing group and the ICAR MedCom. Results: We screened a total of 9,102 articles, of which 120 articles met the inclusion criteria. We developed 17 recommendations graded according to the strength of recommendation and level of evidence. Conclusions: Most of the recommendations from 2012 are still valid. We made minor changes regarding the safety of rescuers and responses to primary or traumatic cardiac arrest. The criteria for termination of CPR remain unchanged. The principal changes include updated recommendations for mechanical chest compression, point of care ultrasound (POCUS), extracorporeal life support (ECLS) for hypothermia, the effects of water temperature in drowning, and the use of burial times in avalanche rescue.

Clinical and microbiological features of drowning-associated pneumonia: a retrospective multicentre cohort study

OBJECTIVE

Pneumonia is the most frequent infectious complication in patients who have experienced drowning that requires intensive care unit (ICU) admission. We aimed to describe clinical, microbiological, and therapeutic data as well as predictors and impacts of such pneumonia on patients' outcomes.

METHODS

We conducted a retrospective, multicentre study (2013-2020) of 270 consecutive patients admitted for drowning to 14 ICUs in Western France. Their baseline characteristics and outcomes were compared according to the occurrence of drowning-associated pneumonia (DAP), defined as pneumonia diagnosed within 48 hours of ICU admission. A Cox regression model was used to compare survival on day 28, and logistic regression was used to identify risk factors for DAP. Microbiological characteristics and empirical antibacterial treatment were also analysed.

RESULTS

Among the 270 patients admitted to the ICU for drowning, 101 (37.4%) and 33 (12.2%) experienced pneumonia and microbiologically proven DAP, respectively. The occurrence of pneumonia was associated with higher severity scores at ICU admission (median Simplified Acute Physiology Score II, 34 [interquartile range {IQR}, 25-55] vs. 45 [IQR, 28-67]; p 0.006) and longer ICU length of stay (2 days [IQR, 1-3] vs. 4 days [IQR, 2-7]; p < 0.001). The 28-day mortality rate was higher among these patients (29/101 [28.7%] vs. 26/169 [15.4%]; p 0.013). Microbiologically proven DAP remained associated with higher 28-day mortality after adjustments for cardiac arrest and water salinity (adjusted hazard ratio, 1.86 [95% CI, 1.06-3.28]; p 0.03). A microbiological analysis of respiratory samples showed a high proportion of gram-negative bacilli (23/56; 41.1%), with a high prevalence of amoxicillin-clavulanate resistance (12/33; 36.4%).

CONCLUSIONS

Pneumonia is a common complication in patients admitted in the ICU for drowning and is associated with increased mortality.

Pre-Existing Medical Conditions: A Systematic Literature Review of a Silent Contributor to Adult Drowning

Medical conditions can increase drowning risk. No prior study has systematically reviewed the published evidence globally regarding medical conditions and drowning risk for adults. MEDLINE (Ovid), PubMed, EMBASE, Scopus, PsycINFO (ProQuest) and SPORTDiscus databases were searched for original research published between 1 January 2005 and 31 October 2021 that reported adult (≥15 years) fatal or non-fatal drowning of all intents and pre-existing medical conditions. Conditions were grouped into the relevant International Classifications of Diseases (ICD) codes. Eighty-three studies were included (85.5% high-income countries; 38.6% East Asia and Pacific region; 75.9% evidence level III-3). Diseases of the nervous system (n = 32 studies; 38.6%), mental and behavioural conditions (n = 31; 37.3%) and diseases of the circulatory system (n = 25; 30.1%) were the most common categories of conditions. Epilepsy was found to increase the relative risk of drowning by 3.8 to 82 times, with suggested preventive approaches regarding supervised bathing or showering. Drowning is a common suicide method for those with schizophrenia, psychotic disorders and dementia. Review findings indicate people with pre-existing medical conditions drown, yet relatively few studies have documented the risk. There is a need for further population-level research to more accurately quantify drowning risk for pre-existing medical conditions in adults, as well as implementing and evaluating population-level attributable risk and prevention strategies.