Mobile Stroke Units in Intracerebral Haemorrhage

ESJ selected paper blog post

Acute intracerebral haemorrhage (ICH) is a devastating condition associated with adverse clinical outcomes and increased mortality. During the last years, the scientific community has rigorously focused on ICH patients and numerous clinical trials have been performed aiming to optimize ICH management. Following a series of “neutral” clinical trials that were mostly focused on antihypertensive treatment or the restriction of hematoma expansion, the third Intensive Care Bundle with Blood Pressure Reduction in Acute Cerebral Haemorrhage Trial (INTERACT3) was presented during the last year’s ESOC, finally announcing positive results for our ICH patients.¹ More specifically, in this trial, implementing a care bundle protocol for intensive ICH management was associated with better clinical outcomes. The care bundle protocol consisted mainly of blood pressure (BP) lowering, but also included other management algorithms for physiological control (correction of hyperglycaemia and hyperpyrexia), and reversal of anticoagulation when needed. And all of the above were offered within the first hour after admission to the hospital, yet within the first 6 hours post stroke onset. Considering that time is brain in ICH as well, one may wonder what if we could restrict even more the time window from symptom onset to administration of such an intensive care bundle protocol.

To that aim, Schwabauer et al. present an exploratory post-hoc analysis of the B-PROUD study,² specifically focusing on ICH patients.³ In this investigator-initiated, non-randomized, controlled clinical trial, a mobile stroke unit (MSU) together with conventional ambulance versus conventional ambulance alone were dispatched for stroke patients according to MSU availability in Berlin. In the present analysis, only ICH patients were considered. When a MSU was dispatched, the patient was offered the possibility to be diagnosed with ICH at the scene and receive antihypertensive treatment and/or anticoagulation reversal when indicated. In case that the patient was transferred by conventional ambulance, antihypertensive agents would be administered only in the case of acute cardiac decompensation, and further management would be offered only after hospital arrival and the establishment of ICH diagnosis.

Between February 2017 and May 2019, 173 ICH patients were included in the study: for 95 of them a MSU was dispatched together with a conventional ambulance, whereas for the rest 78 patients only a conventional ambulance was available to be dispatched. Impressively, the ambulances in both patients’ groups were dispatched as early as 30 minutes post symptom onset, underscoring the high level of patient awareness and the well-organised emergency medical services in Berlin. As expected, MSUs were able to arrive slightly later at the scene compared to conventional ambulances. Yet, brain imaging and, therefore, ICH diagnosis were performed significantly earlier in patients for whom MSUs were dispatched (39 min after dispatch) versus those of the conventional group (57 min after dispatch). Prompt ICH diagnosis allowed for the early administration of antihypertensive treatment in almost 2/3 of the MSU-patients, finally leading to significantly lower SBP levels at hospital arrival among MSU-patients (161 mmHg) compared to conventional care (177 mmHg). However, less than 20% of the patients achieved SBP levels ≤ 140 mmHg at hospital admission, with no difference between the two groups. Perhaps this failure to achieve recommended levels could have contributed to the fact that there was no difference between the two groups when the other outcomes of interest were considered, including mortality at 7 days, largest haematoma volume, and 3-month functional outcome.

Furthermore, considering that there were numerically more deaths at 7 days among the MSU-patients versus the conventional group, the authors argue that aggressive SBP lowering could have led to adverse clinical outcomes, particularly in patients for whom a sudden SBP drop was observed. For this reason, they call attention to the European Stroke Organisation guidelines on blood pressure management and the expert consensus statement recommending that the decrease of SBP in ICH patients should not exceed 90 mmHg from baseline values.⁴ Another protocol suggested by the authors could be to initiate BP lowering in patients with baseline SBP higher than 160 mmHg (rather than 150 mmHg) and to aim at a stable SBP reduction of no more than 10% every 30 minutes, as has now been adopted by the Berlin MSU medical teams. Yet, such a suggestion should be further investigated before being implemented in other settings.

Although MSU dispatch was not associated with better clinical outcomes in this study, it should be highlighted that MSU may offer further opportunities for the optimization of the management of ICH patients, that include not only BP reduction but also ultra-early diagnosis, prehospital triage and bypass to neurosurgical centers.⁵ Additionally, no safety concerns have been previously identified for ICH patients being managed with a MSU compared to conventional care.⁶ We should continue our efforts to provide the best care possible to ICH patients by implementing an active protocol, including (but not restricted to) intensive, yet cautious, BP lowering and dispatching MSU when possible.

Read the selected ESJ paper

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References:

1. Ma L, Hu X, Song L, Chen X, Ouyang M, Billot L, et al. The third Intensive Care Bundle with Blood Pressure Reduction in Acute Cerebral Haemorrhage Trial (INTERACT3): an international, stepped wedge cluster randomised controlled trial. Lancet. 2023;402:27-40
2. Rohmann JL, Piccininni M, Ebinger M, Wendt M, Weber JE, Schwabauer E, et al. Effect of Mobile Stroke Unit Dispatch in all Patients with Acute Stroke or TIA. Ann Neurol. 2023;93:50-63
3. Schwabauer E, Piccininni M, Freitag E, Ebinger M, Geisler F, Harmel P, et al. Effects of Mobile Stroke Unit dispatch on blood pressure management and outcomes in patients with intracerebral haematoma: Results from the Berlin_ Prehospital Or Usual Care Delivery in acute Stroke (B_PROUD) controlled intervention study. European Stroke Journal. 2023;X:X
4. Sandset EC, Anderson CS, Bath PM, Christensen H, Fischer U, Gąsecki D, et al. European Stroke Organisation (ESO) guidelines on blood pressure management in acute ischaemic stroke and intracerebral haemorrhage. Eur Stroke J. 2021;6:Xlviii-lxxxix
5. Cooley SR, Zhao H, Campbell BCV, Churilov L, Coote S, Easton D, et al. Mobile Stroke Units Facilitate Prehospital Management of Intracerebral Hemorrhage. Stroke. 2021;52:3163-3166
6. Walter S, Audebert HJ, Katsanos AH, Larsen K, Sacco S, Steiner T, et al. European Stroke Organisation (ESO) guidelines on mobile stroke units for prehospital stroke management. Eur Stroke J. 2022;7:Xxvii-lix