Hyperbaric oxygen therapy ameliorates acute brain injury after porcine intracerebral hemorrhage at high altitude

Abstract

IntroductionIntracerebral hemorrhage (ICH) at high altitude is not well understood to date. This study investigates the effects of high altitude on ICH, and examines the acute neuroprotection of hyperbaric oxygen (HBO) therapy against high-altitude ICH.MethodsMinipigs were placed in a hypobaric chamber for 72 h before the operation. ICH was induced by an infusion of autologous arterial blood (3 ml) into the right basal ganglia. Animals in the high-altitude ICH group received HBO therapy (2.5 ATA for 60 min) 30 min after ICH. Blood gas, blood glucose and brain tissue oxygen partial pressure (PbtO2) were monitored continuously for animals from all groups, as were microdialysis products including glucose, lactate, pyruvate and glutamate in perihematomal tissue from 3 to 12 h post-ICH.ResultsHigh-altitude ICH animals showed significantly lower PbtO2, higher lactate/pyruvate ratio (LPR) and glutamate levels than low-altitude ICH animals. More severe neurological deficits, brain edema and neuronal damage were also observed in high-altitude ICH. After HBO therapy, PbtO2 was significantly increased and LPR and glutamate levels were significantly decreased. Brain edema, neurological deficits and neuronal damage were also ameliorated.ConclusionsThe data suggested a more serious disturbance of tissue oxygenation and cerebral metabolism in the acute stage after ICH at high altitude. Early HBO treatment reduced acute brain injury, perhaps through a mechanism involving the amelioration of the derangement of cerebral oxygenation and metabolism following high-altitude ICH.

An Intersectional Study of LncRNAs and mRNAs Reveals the Potential Therapeutic Targets of Buyang Huanwu Decoction in Experimental Intracerebral Hemorrhage

“…Previous studies have demonstrated the accumulation of lactate, which results in low pH values in the hematoma and perihematomal regions [42], as also demonstrated by our group (unpublished data). According to the Bohr effect, an acidic environment causes oxygen to dissociate from hemoglobin, leading to increased deoxyhemoglobin and dissociated oxygen.…”

Oxygen - a limiting factor for brain recovery

“…In a hypobaric environment, oxygen delivery decreases below the minimal metabolic needs. Zhu et al [ 1 ] have shown that in ICH in a hypobaric environment, when paO 2 reached 63–66 mm Hg and the diffusion distance for oxygen delivery from microvasculature to brain tissue was expanded because of edema, extravascular blood accumulation, and structural damage of adjacent tissue, the PbTO 2 is as low as 9–14 mm Hg. Consequently, achieving higher tissue oxygen tension and paO 2 is crucial for maintaining sufficient oxygenation of the damaged brain tissue.…”

“…At high altitude, the prognosis of ICH is worsened and one of the possible explanations relates to the lower oxygen concentration. In a recent article by Zhu et al [ 1 ], this claim was challenged by exposing minipigs with ICH to hypo-, normo-, and hyperbaric environments. In a hypobaric setting, compared with a normobaric environment, brain tissue oxygenation (PbTO 2 ), brain metabolism (lactate, lactate–pyruvate ratio, and glutamate), and neurological scores were significantly worsened.…”

Establishment and imaging evaluation of Guangxi Ba-Ma mini pigs as a model of cerebral hernia induced by acute intracranial hypertension

“…Many diseases can lead to increased intracranial pressure (ICP), such as traumatic brain injury, hypertensive cerebral hemorrhage, brain tumor, meningitis, and hepatic encephalopathy [10]. Some researchers have used rats, rabbits and pigs as experimental animals to study intracranial hypertension [14,12,13], but few studies have described animal models of brain hernia. Here we describe the Guangxi Ba-Ma mini-pigas a potential model of cerebral hernia induced by acute intracranial hypertension in order to lay a subsequent research in emergency medicine.…”