Background: Lowering of blood pressure (BP) is discouraged in current ASA guidelines for emergency medical service (EMS) personnel. However, ultra-early treatment with IVtPA and BP lowering in ICH are possible on mobile stroke units (MSU). We examined the effectiveness and safety of two antihypertensive agents for MSU treatment.
Methods: Consecutive MSU patients were treated with target ICH BP parameters less than 140/90, and IVtPA BP parameters by current guidelines. BP was measured by noninvasive oscillometric cuff, and cycled every 5 minutes per EMS MSU protocol. Available agents were labetalol IV 10-20mg and/or nicardipine double-strength premix infusion started at 5mg/hour and titrated. Preference in usage, and effect were recorded and analyzed for the first year of MSU operation.
Results: During 168 service days, 127 acute stroke patients were transported (68±16, range 23-96 years; 58% women; 65% African American, 34% White; 1% Hispanic). Fifteen (12%) had hemorrhage on CT (1 aneurysmal SAH, 1 SDH, 1 subacute AIS with HT-2; 12 HTN ICH [median ICH score 2, IQR 1-3] of which 1 had a positive spot sign on CTA). AIS cases (n=100) had median NIHSS 9 (IQR 7-17); 38% were treated with IVtPA at a median 13 (IQR 11-16) minutes from scene arrival, one of these by IO route, with 1 angioedema and 0 sICH. Labetalol was used for 9 patients, with all but one (89%) requiring the addition of nicardipine infusion. In 24 patients nicardipine was the first agent selected, with 100% achieving target BP control prior to hospital arrival.
Conclusions: MSU use of nicardipine double-strength premix infusions provides rapid, reliable, and safe BP control. When time is of the essence, elimination of labetalol, in favor of a dihydropyridine calcium channel blocker infusion may provide the most rapid achievement of prescribed BP parameters.