Clinicians' prediction of advanced cardiopulmonary variables in critically ill patients: a multicenter study

Introduction

Lack of evidence that more advanced monitoring techniques improve outcome may have led to insufficient monitoring of critically ill patients. However, clinical judgment and conventional hemodynamic monitoring alone were shown to be inadequate for a reliable estimate of hemodynamic status. We have therefore compared clinicians' prediction of advanced cardiopulmonary parameters with actual measurements.

Methods

Cardiopulmonary assessment was done in critically ill patients from 12 European ICUs just before the use of the PiCCO monitor (Pulsion, Germany). Independent prediction of cardiac output (CO), systemic vascular resistance (SVR), indexed global end-diastolic volume (GEDVi), stroke volume variation (SVV), and indexed extravascular lung water (EVLWi) was done by one to four physicians per patient. Following the first set of PiCCO measurements each physician self-rated the accuracy of his pre-PiCCO predictions.

Results

A total of 257 questionnaires of 165 patients (67 females and 98 males, age 59.8 ± 16.7 (range 16–93) years) were completed by 135 residents and 122 specialists. The main reasons for using the PiCCO included unclear fluid status (109 cases), sepsis/septic shock (70 cases), respiratory failure (42 cases), cardiogenic shock (19 cases), renal failure (27 cases), and other (18 cases). Only 30–50% of the predicted values were correct (± 20% of measured values) (Table 1). Ranges of errors were: CO (-77/+100%), SVR (-94/+303%), GEDVi (-88/+135%), SVV (-91/+367%), EVLWi (-76/+650%). There was a significant underestimation of CO (P < 0.00001) and GEDVi (P < 0.0003), and overestimation of SVR (P < 0.003) and SVV (P < 0.0002).

Table 1 (abstract P284)

The 240 self-ratings (scale of 1–5, [1] = excellent; [5] = poor) of predictions accuracy included – [1] 1.6%, [2] 40%, [3] 38.8%, [4] 15.1%, [5] 4.5%. The mean self-rate was 2.8 ± 0.9, with that of residents (2.8 ± 0.9, n = 129) being similar to that of specialists (2.7 ± 0.8, n = 111), P < 0.31.

Conclusion

The ability of physicians to predict advanced cardiopulmonary parameters based on clinical evaluation and conventional monitoring alone has considerable limitations and is not improved by experience.