A case of cerebral aneurysm rupture and subarachnoid hemorrhage associated with air travel

Abstract

During air travel, passengers are exposed to unique conditions such as rapid ascent and descent that can trigger significant physiological changes. In addition, the cabins of commercial aircraft are only partially pressured to 552–632 mmHg or the equivalent terrestrial altitudes of 1,500–2,500 m (5,000–8,000 feet) above sea level. While studies in high-altitude medicine have shown that all individuals experience some degree of hypoxia, cerebral edema, and increased cerebral blood flow, the neurological effects that accompany these changes are otherwise poorly understood. In this study, we report a case of acute subarachnoid hemorrhage from a ruptured cerebral aneurysm associated with travel on commercial aircraft. We then review relevant cases of neurological incidents with possible air travel-related etiology and discuss the physiological factors that may have contributed to the patient’s acute subarachnoid hemorrhage. In the future, this report may serve as reference for more detailed and conservative medical guidelines and recommendations regarding air travel.

Superficial Temporal Artery True Fusiform Aneurysm With Several Lateral Feeding Vessels

“…Finally, as a flight attendant for the past 25 years, the patient was exposed to repetitive cycles of pressurization and depressurization and acceleration and deceleration during flight take-off and landing. These cycles are associated with transient compensatory increases in blood pressure and resultant tension on the arterial wall, which over time may contribute to aneurysmal degeneration [ 16 , 17 ].…”

Flight-Related Aneurysmal Subarachnoid Hemorrhage and Its Complications During and after Landing

“…Admission clusters of patients with SAH following a drop in barometric pressure have been reported [1,[3][4][5]; changing climatic conditions preceding aneurysm rupture were characterized by a fall in maximum daily barometric pressure of greater than 55mmHg [1]. Atmospheric pressure is 760 mmHg at sea level; commercial air craft cabins at a cruising altitude of 11000 m are pressurized at the atmospheric pressure found at 5000-8000ft (2000-2500 meters), equivalent to 632-552mmHg [7,8]. This hypobaric condition in air travel generally induces some hypoxemia, brain swelling and increase of cerebral blood flow [9].…”

“…Under this aspect, it is interesting to note that hemorrhage tends to occur during descent or immediately after, which probably represents the most sensitive phase of flight [7][8][9][10].…”

“…The effect of reactive increased cerebral blood flow related to decreased in blood oxygen saturation may contribute to in-flight aneurysm rupture [7], and to adverse consequences in terms of rebleeding and intracerebral hemorrhagic extension. Cerebral hypoxia may be associated also with significant increases in cerebral artery diameters [11], which may modify aneurysm haemodynamics and promote bleeding.…”

Factor XIII polymorphism and risk of aneurysmal subarachnoid haemorrhage in a south Indian population

“…Most candidate gene studies have considered proteins associated with connective tissue organization [ 5 – 7 ]. The reason for SAH occurrence was not only due to weakened vessel wall structure but also due to rupture of vessel wall [ 8 ]. A few studies have investigated the role of fibrinolytic system and coagulation factors association with the risk of aSAH [ 9 – 11 ].…”