A study intended to examine the impact of different weather conditions and modes of transport on mechanical thrombectomies in stroke patients has found a link between higher temperatures and improved outcomes—whereas daily drizzle was associated with poorer post-thrombectomy outcomes.
As such, lead author Pascal Jabbour (Thomas Jefferson University Hospital, Philadelphia, USA) and colleagues posit that “further studies are needed to modify transfer protocols, especially during cold and rainy days, and potentially improve outcomes”.
Writing in the journal Neurosurgery, Jabbour et al detail how they retrospectively collected data for stroke patients transferred from a ‘spoke’ centre to their ‘hub’ hospital to undergo a mechanical thrombectomy between 2017 and 2021.
The researchers did this to assess how varying weather conditions may influence stroke risk, as well as patient transfer protocols and outcomes, as the efficient transfer of patients with stroke to a mechanical thrombectomy-capable centre is “essential”.
Jabbour et al included a total of 543 patients with a mean age of 71.7 years in their study. In these patients, they observed an increase in median National Institutes of Health Stroke Scale (NIHSS) score from 14 to 15 after transportation; while the median modified Rankin Scale (mRS) score was 4 at discharge and 90 days, and 3 at the final follow-up (mean time=91.7 days).
“Higher daily temperatures were associated with good outcomes, whereas daily drizzle was associated with poor outcomes,” the authors report. “More patients were transferred by air when visibility was better, and by ground during heavier precipitation, higher humidity, rain, mist, daily drizzle, fog, and thunder.”
However, Jabbour and his colleagues ultimately did not find an association between transportation mode and patient outcomes. And, across the independent predictors of a good outcome, none were determined to be a weather variable. Lower hourly relative humidity (p=0.003) and longer road distance (p<0.001) were independent predictors of using air transportation, among others, they add.
Speaking to NeuroNews to outline potentially beneficial modifications to transfer protocols, Jabbour said: “It depends on how far [away] the spoke hospital is. Ground versus air transport should be chosen according to which one is faster; above a certain distance, air transport makes more sense. Adverse weather affects all kinds of transport. A traffic map evaluation should be done as soon as a transport team is getting ready to be dispatched—keeping in mind that, sometimes, there is no choice, [as] the weather does not permit air transport.”
And, discussing further studies in this space, Jabbour added: “Future randomisation between different types of transport would help us determine, in a scientific way, which modality to choose, and will help us match the best transport type with each patient according to weather and location.”