Agreement between standard and continuous wireless vital sign measurements after major abdominal surgery: a clinical comparison study

Objective. Continuous wireless monitoring outside the post-anesthesia or intensive care units may enable early detection of patient deterioration, but good accuracy of measurements is required. We aimed to assess the agreement between vital signs recorded by standard and novel wireless devices in postoperative patients. Approach. In 20 patients admitted to the post-anesthesia care unit, we compared heart rate (HR), respiratory rate (RR), peripheral oxygen saturation (SpO₂), and systolic and diastolic blood pressure (SBP and DBP) as paired data. The primary outcome measure was the agreement between standard wired and wireless monitoring, assessed by mean bias and 95% limits of agreement (LoA). LoA was considered acceptable for HR and PR, if within ±5 beats min⁻¹ (bpm), while RR, SpO2, and BP were deemed acceptable if within ±3 breaths min⁻¹ (brpm), ±3%-points, and ±10 mmHg, respectively. Main results. The mean bias between standard versus wireless monitoring was −0.85 bpm (LoA −6.2 to 4.5 bpm) for HR, −1.3 mmHg (LoA −19 to 17 mmHg) for standard versus wireless SBP, 2.9 mmHg (LoA −17 to 22) for standard versus wireless DBP, and 1.7% (LoA −1.4 mmHg to 4.8 mmHg) for SpO₂, comparing standard versus wireless monitoring. The mean bias of arterial blood gas analysis versus wireless SpO₂ measurements was 0.02% (LoA −0.02% to 0.06%), while the mean bias of direct observation of RR compared to wireless measurements was 0.0 brpm (LoA −2.6 brpm to 2.6 brpm). 80% of all values compared were within predefined clinical limits. Significance. The agreement between wired and wireless HR, RR, and PR recordings in postoperative patients was acceptable, whereas the agreement for SpO₂ recordings (standard versus wireless) was borderline. Standard wired and wireless BP measurements may be used interchangeably in the clinical setting.