Subarachnoid Hemorrhaging Occurring during Drowning

Dear Editor, A 37-year-old healthy man presented with impaired consciousness and hypoxemia after drowning. While swimming together, his wife began to struggle in the water, prompting him to attempt to rescue her. His wife was successfully rescued. However, the patient nearly drowned, and despite being rescued, experienced cardiac arrest. Cardiopulmonary resuscitation was administered, and the pulse was reestablished. Due to ongoing hypoxemia and impaired consciousness, he was intubated by medical staff from a helicopter. On arrival, he exhibited deep coma, high blood pressure, and sinus tachycardia. On a physical examination, no external trauma was observed; however, moist rales were heard in both lung fields. A 12-lead electrocardiogram revealed sinus tachycardia. Blood tests indicated leukocytosis and mild liver and kidney dysfunction. A whole-body computed tomography (CT) revealed a small amount of subarachnoid hemorrhaging near the left central sulcus of the frontal lobe [Figure 1], bilateral maxillary sinus fluid accumulation, and infiltrative shadows in both lungs. On day 2, as the respiratory status improved, extubation was performed. Due to incomplete awakening and worsening respiratory status, reintubation was required. On day 4, the patient was confirmed to be adequately awake, and extubation was repeated. A head magnetic resonance imaging (MRI) and contrast-enhanced CT did not reveal any clear sources of bleeding. The patient was discharged on day 7 without neurological deficits.Figure 1: A head computed tomography (CT) scan on obtained arrival. CT revealed a small amount of subarachnoid hemorrhaging near the left central sulcus of the frontal lobe (arrow)This case represents a unique occurrence of subarachnoid hemorrhaging without a clear source during drowning, with no prior reports of such a combination. Previously, there have been cases in which subarachnoid hemorrhaging occurred as a complication of asphyxiation, stemming from preexisting vascular abnormalities.[1] In addition, there have been cases of subarachnoid hemorrhaging resulting from bleeding from cavernous angiomas during diving, although whether drowning or bleeding occurred first remains unclear.[2] In both scenarios, it is possible that hypoxemia due to asphyxiation led to elevated blood pressure, causing bleeding from abnormal vascular sites. However, in the present case, neither MRI nor CT angiography revealed any apparent vascular abnormality. Although high blood pressure can sometimes lead to subarachnoid hemorrhaging of unknown origin, the common site of bleeding in such cases is the perimesencephalic cistern.[3] In the present case, the location of bleeding was different, near the central sulcus of the brain. In addition, this patient had no history of hypertension. We propose one hypothesis concerning the possible mechanisms involved in this case. Elevation of cerebral venous pressure due to breath holding during drowning may have been responsible. During drowning, individuals may hold their breath to prevent ingesting water in an attempt to survive. This action can increase pressure within the chest and, in turn, elevate cerebral venous pressure.[4,5] A sudden increase in cerebral venous pressure can exert pressure on the blood vessels of the brain, possibly causing them to rupture. Cases such as these are rare, and further research and investigation are needed for a more detailed understanding. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Research quality and ethics statement The authors followed applicable EQUATOR Network (https://www.equator-network.org/) guidelines, notably the CARE guideline, during the conduct of this report. Financial support and sponsorship This work was supported in part by a Grant-in-Aid for Special Research in Subsidies for ordinary expenses of private schools from the Promotion and Mutual Aid Corporation for Private Schools of Japan. Conflicts of interest There are no conflicts of interest.