Figure 2From: Trial design: Computer guided normal-low versus normal-high potassium control in critically ill patients: Rationale of the GRIP-COMPASS study Planned patient allocation scheme. To create two comparable groups while reducing bias from various time-dependent system effects the GRIP computer is instructed to regularly alternate between the targets of 4.0 and 4.5 mmol/L. The goal is to include 50 patients in each block, where the precise timing of a block change may also depend on logistic factors.Back to article page