Supplemental oxygen delivery to suspected stroke patients in pre hospital and emergency department settings

Abstract

BackgroundRecent data suggests that high-flow oxygen started promptly after stroke symptom onset salvages ischemic brain tissue. We investigated the consistency of oxygen delivery to suspected stroke patients in the pre-hospital (PH) and Emergency Department (ED) settings, and associated adverse events (AEs).MethodsWe retrospectively reviewed pre-hospital call reports of suspected stroke patients transported by our institution’s paramedics. We extracted data on oxygen delivery in the PH and ED settings, demographics, Glasgow Coma Scale score (GCS), final diagnosis, and selected AEs (mortality, seizures, worsening neurological status, new infarction, and post-ischemic hemorrhage). Patients were grouped according to ED oxygen delivery: none, low-flow (2-4 L/min), and high-flow (10-15 L/min).ResultsOxygen delivery was documented in 84% of 366 stroke transports, with 98% receiving 10-15 L/min. Our hospital received 164 patients. Oxygen delivery in the ED was documented in 150 patients, with 38% receiving none, 47% low-flow, and 15% high-flow oxygen. There were no instances of oxygen refusal, premature termination, or technical difficulties. Advanced age and low GCS predicted the use of higher flow rates. High-flow oxygen was more frequently administered to patients with symptom onset < 3 hours, and those with intracerebral hemorrhage (ICH), hypoxic-ischemic encephalopathy (HIE) or seizures (p < 0.001). More patients receiving high-flow oxygen were documented to have an AE (p = 0.02), however the low- and no-oxygen groups more frequently had multiple AEs (p = 0.01). The occurrence of AEs was predicted by the diagnosis of ICH/HIE/seizures (p = 0.013) and acute ischemic stroke (AIS)/transient ischemic attack (TIA) (p = 0.009), but not by the amount of oxygen.ConclusionsSuspected stroke patients routinely receive 10–15 L/min oxygen in the ambulance however in the ED there is wide variability due to factors such as clinical severity. Oxygen delivery appears safe in the PH and ED settings.

Physiological Variability during Prehospital Stroke Care: Which Monitoring and Interventions Are Used?

“…The patients were categorized based on the amount of oxygen administered in the ED: none, low-flow (2-4 L/min), and high-flow (10-15 L/min). In comparison with the low-flow and no-oxygen groups, the highflow group had a lower occurrence of adverse events (defined as death rate, neurological deterioration status, or occurrence of ischemic event) [57]. Thus, neither of the retrospective studies reported any neurologic harm associated with oxygen administration.…”

“…It was demonstrated that neurological outcomes (defined as mRS and ambulatory status) did not differ among the three groups (hyperoxia, hypoxia and normoxia) [56]. Additionally, a retrospective analysis examined the reliability of oxygen administration to suspected stroke subjects in the ED and out-of-hospital setting and explored adverse events among these patients [57]. The patients were categorized based on the amount of oxygen administered in the ED: none, low-flow (2-4 L/min), and high-flow (10-15 L/min).…”

Stroke, Oxygen and Prehospital Care: A Commentary on Current Treatments and Opportunities for Improvement

“…The frequency of adverse events was lower in the high-flow oxygen group. Adverse events and oxygen treatment were found to be associated with diagnoses of intracerebral hemorrhage, encephalopathy, and seizure but not with amount of oxygen delivered [40]. Thus, neither Dylla et al nor Chan et al found oxygen treatment to be associated with neurologic harm and both found disease severity and final diagnosis to be drivers of oxygen treatment.…”

Emergency Management of Acute Ischaemic Stroke

“…Supplemental oxygen can be administered at a dose of 10-15 L/min if there is evidence of hypoxia by pulse oximetry. This was shown to slow down the process of ischaemia and extend the therapeutic time window for thrombolysis [20,21]. Patients with depressed level of consciousness should be intubated to avoid the risk of aspiration [22].…”