Fig. 2

a Mean excitability data ± SE for 31 healthy subjects (n = 31, green curve), ICU controls (n = 12, blue curve), and CIP patients (n = 14, red curve). (1) I/V slope. (2) Stimulus-response relationship. (3) Threshold electrotonus. (4) Excitability recovery. b Correlation between healthy controls (n = 31, green boxes), ICU controls (n = 12, blue boxes), and CIP patients (n = 14, red boxes) for superexcitability %, TEd_{(10–20 ms)}, S2 accommodation, resting I/V slope, strength-duration time constant, rheobase, sub-excitability, and TEh (overshoot). Differences between groups are indicated as *p < 0.05; **p < 0.01; ***p < 0.0001. c Correlation between laboratory parameters and excitability parameters in ICU controls (n = 12) and CIP patients (n = 14). pCO₂ and TEd_{(10–20 ms)} (p = 0.007). KCl mmol/l infusion rate mean/day for the first 14 days on ICU and sub-excitability. Significant correlation in CIP patients (p = 0.026), contrary to ICU control patients (p = 0.159)