Objective: To evaluate the clinical role and cost effectiveness of transcutaneous pCO 2 monitoring compared to arterial line sampling during the acute phase of non-invasive ventilation therapy. Subjects and methods: Ten inpatients were recruited at the Medical High Dependency Unit, Queen's Medical Centre, Nottingham. All were receiving NIV for acute hypercapnic respiratory failure and had arterial lines placed. During 48 hours of concurrent monitoring with Radiometer transcutaneous TOSCA TCM4 and arterial ABL90 blood gas analysers the staff-time, consumables and proportionate hardware costs were determined and compared. Patient-reported pain scores were analysed using the Wilcoxon signed rank test, and pCO 2 data from each monitor were plotted as time trends. Results: Over 48-hour periods, a mean 16 samples were taken from each patient. Transcutaneous monitoring was less painful and produced pCO 2 time trends concordant to arterial sampling. Staff-time costs to establish monitoring and obtain data were £0.13 (transcutaneous) and £1.83 (arterial) per sample. Consumable and disposal costs were £3.35 (transcutaneous) and £3.74 (arterial) per sample taken. Initial device purchase and estimated device-life readings corresponded to hardware costs of £0.78 (transcutaneous) and £1.37 (arterial) per sample. Conclusions: Transcutaneous pCO 2 monitoring provided reliable time trends, improved patient experience and was cost effective (£4.27 vs £6.94) compared to arterial lines. For a unit that provides acute NIV for 148 patients each year, monitoring transcutaneous rather than arterial pCO 2 would represent an annual saving of £6325.
Oppen et al. (Mon,) studied this question.