Introduction: Techniques for measuring volume status of critically ill patients include invasive, less invasive, or noninvasive ones. The present study aims to assess the accuracy of noninvasive techniques for measuring volume status of critically ill patients.
Patients and methods: A total of 111 critically ill patients admitted to the emergency department and undergoing central venous catheterization were included in the study. Five parameters were measured including vascular pedicle width (VPW), diameter of inferior vena cava, caval index, respiratory changes in QRS, and P wave amplitude. Patients with risk factors which could decrease the accuracy of central venous pressure (CVP) value were excluded from study. We compared these parameters with static CVP parameter. Finally, based on the afore-mentioned parameters, PCQP role in criteria was designed.
Results: In detecting loss of circulating blood volume, area under the curve of VPW was 0.92 (90%, confidence interval [CI]: 0.85-0.99), diameter of inferior vena cava was 0.82 (90%, CI: 0.72-0.91), caval index was 0.9 (90%, CI: 0.82-0.98), and changes in QRS and P waves were 0.88 (95%, CI: 0.81-0.95) and 0.73 (95%, CI: 0.63-0.82), respectively. PCQP role in criteria was designed according to these parameters, and at its best cutoff point (score 6), VPW had a sensitivity of 97.4% (95%, CI: 84.57-99.99) and specificity of 83.6% (95%, CI: 72.65-90.86) for the detection of loss of circulating blood volume (<8 cmH2O).
Conclusion: PCQP score could be a reliable and noninvasive technique for the assessment of volume status in critically ill patients.
Keywords: Caval index; central venous pressure; changes in electrocardiographic wave; diameter of inferior vena cava; pulmonary vein pedicle.