Utilisation of the National Early Warning Score (NEWS) and Assessment of Patient Outcomes Following Cardiac Surgery.

The national early warning score (NEWS) was introduced to improve the detection of, and standardise the assessment of, the severity of acute illness in the National Health Service (NHS). We assessed whether the recommended threshold trigger score of 5 or more in a Critical Care Outreach Team (CCOT) review could accurately predict patients at risk of deterioration following cardiac surgery and patient outcomes. We investigated adult cardiac surgery patients between October 2019 and December 2021. NEWS 2 parameters triggering CCOT referrals and NEWS 2 parameters < 5 versus ≥5 were compared, and the resulting patient outcomes were evaluated. Over this period, 3710 patients underwent surgery, of whom 162 (4.4%) initiated 193 calls to the CCOT. The mean number of NEWS 2 parameters on CCOT activation was 6.14 ± 2.43 (NEWS 0-16); 34 (20.98%) activations were from patients with NEWS 2 < 5. Low oxygen saturation (SpO) (59.3%) and oxygen therapy (83.3%) were the most common physiological parameters raising the score. CCOT activations led to 38 transfers from the ward to the high-dependency unit (HDU) and 18 transfers to the intensive therapy unit (ITU). Cardiac arrest calls were initiated in 12 (7.40%) patients and two culminated in death. Fourteen (8.64%) had emergency resternotomy. The in-hospital mortality rate was 10.5% (17/162) in patients referred to CCOT versus 3.9% (139/3548) in patients who were not ( < 0.001). The in-hospital mortality in patients with NEWS 2 < 5 vs. NEWS ≥ 5 was 17.6% (6/34) versus 8.6% (11/128) ( = 0.126). There was no difference in in-hospital mortality in patients below or above a NEWS 2 of 5, but there was a significant difference in in-hospital mortality in patients reviewed by the CCOT ( < 0.001). Tailoring the threshold score specifically for the cardiac surgical cohort, in conjunction with clinician involvement, may improve outcomes.