RESUMO
BACKGROUND: Arterial pressure lability is common during the process of replacing syringes used for norepinephrine infusions in critically ill patients. It is unclear if there is an optimal approach to minimise arterial pressure instability during this procedures. We investigated whether 'double pumping' changeover (DPC) or automated changeover (AC) reduced blood pressure lability in critically ill adults compared with quick syringe changeover (QC). METHODS: Patients requiring a norepinephrine infusion syringe change were randomised in a non-blinded trial undertaken in six ICUs. Randomisation was minimised by norepinephrine flow rate at inclusion and centre. The primary outcome was the frequency of increased/decreased mean arterial pressure (defined by 15 mm Hg from baseline measurements) within 15 min of switching the syringe compared with QC. RESULTS: Patients (mean age: 64 (range:18-88)) yr were randomly assigned to QC (n=95), DPC (n=95), or AC (n=96). Increased MAP was the commonest consequence of syringe changeovers. MAP variability was most frequent after DPC (89/224 changeovers; 39.7%) compared with 57/223 (25.6%) changeovers after quick syringe switch and 46/181 (25.4%) in patients randomised to receive automated changeover (P=0.001). Fewer events occurred with QC compared with DPC (P=0.002). Sensitivity analysis based on mixed models showed that performing several changeovers on a single patient had no impact. Both type of changeover and norepinephrine dose before syringe changeover were independently associated with MAP variations >15 mm Hg. CONCLUSIONS: Quick changeover of norepinephrine syringes was associated with less blood pressure lability compared with DPC. The prevalence of MAP variations was the same between AC and QC. CLINICAL TRIAL REGISTRATION: NCT02304939.