[Relationship between severity of illness and mental status in ICU conscious patients: a nationwide multi-center...

To survey the incidence of psychological adverse events in critical conscious patients during their ICU stay and analyze the relationship between the incidence and the severity of illness.

234 conscious patients, 133 males and 101 females, aged (55.4 +/- 19.6), 80 with internal medicine diseases and 154 with surgical diseases, were treated in the ICUs of 31 grade 3 A hospitals over the country consecutively during the period of 2 months and then successfully transferred to other departments. The patients were interviewed with specific questionnaire within the 2 days after transfer to investigate the incidence of anxiety and depression and the tolerance of invasive medical and nursing procedures of the patients.

The overall incidence of psychological adverse events (PAE) was 69.6%. Multi-variate Logistic analysis showed that acute physiology and chronic health evaluation (APACHE) II score was an independent high risk factor of PAE (OR = 1.07, 95% CI: 1.02-1.13, P < 0.05). The relative risk (RR) values of the patients with APACHE II scores 1-10, 11-20, and >20 were 1.29, 2.53, and 4. 85 respectively. The higher the APACHE II score, the more invasive interventions received (P < 0.01) , and the lower the mental stress threshold (P < 0.01) the higher the incidence of PAE (P < 0.01). The APACHE II scores of those who failed to tolerate noise and medical and nursing procedures were 15.8 +/- 5.7 and 16.5 +/- 6.1 respectively, both significantly higher than those of the patients who tolerated (12.1 +/- 4.4, P < 0.05; and 10.6 +/- 2.9, P < 0.01).

APACHE II score is an independent high risk factor of PAE. The conscious ICU patients with higher APACHE II scores receive more invasive medical and nursing procedures. Low mental stress threshold greatly contributed to the incidence of PAE in ICU conscious critical patients with high APACHE II score.