Perioperative non-invasive measurement of a patient's peripheral arterial oxygen saturation has become an accepted standard of care endorsed by anaesthesiologists and their regulatory bodies throughout the world. Pulse oximeters are an integral item on the World Health Organisation's Surgical Safety Checklist which is performed prior to the commencement of every surgical procedure. They are also utilised by other medical professionals and patients in various scenarios. When compared to conventional bedside pulse oximeters, portable fingertip devices have the advantages of cost-effectiveness, high portability, ease of use and battery operation. A review of recent literature reveals a paucity of accuracy studies in adult patients with various comorbidities in the clinical setting. Most data has been obtained under ideal laboratory conditions utilizing healthy adult volunteers. This study aims to pragmatically investigate the performance of a portable fingertip pulse oximeter in adult patients in a hospital setting.

The purpose of this prospective, quantitative study is to compare the agreement between the measured arterial oxygen saturation levels using a portable fingertip versus a conventional bedside pulse oximeter in adult surgical patients, presenting for elective and emergency surgery to Groote Schuur Hospital over a four-week period. Adult surgical patients, not meeting any exclusion criteria, who present for elective or emergency surgery will be recruited. 200 data pairs (SpO2, heart rate and skin tone) will be recorded in the perioperative period (operating rooms, recovery room and intensive care unit).

Existing monitoring devices will not be disturbed. The agreement between the two devices will be compared using a Bland-Altman plot, Microsoft Excel and SPSS software. A root mean square difference value will also be calculated from these values.

No sensitive or personal patient information will be recorded, and pulse oximetry is essential harmless. Potential cross-infection will be avoided by excluding patients with known communicable diseases or open wounds/ bodily fluids in the area to have the oximeter probes applied. The study devices will be disinfected after each use. Recruitment will not affect clinical care.

The significance of this study into the performance of portable fingertip pulse oximeters in adult surgical patients will result in the availability of cheaper devices, deemed as vital anaesthetic equipment by the WHO and various anaesthetic regulatory bodies, in lower income medical facilities. It will also give anaesthetists and other medical personal the confidence to make clinical decisions based on these highly portable devices, thereby making pulse oximeters more available in resource limited areas. It will also add further data to existing studies and help assess whether darker skin pigment affects the performance of these devices in the clinical setting, which is highly relevant in an African country like South Africa.

Inclusion Criteria:

• Adult surgical patients presenting for elective or emergency surgery

Exclusion Criteria:

• Contact precautions due to high risk of transmissable infectious disease
• Significant hypotension or hypoperfusion (systolic blood pressure <80 mmHg, or hypothermia)
• Motion artefacts due to excessive patient movements
• Known presence of variant haemoglobin species (eg. carboxy- or methaemoglobin)
• Intraoperative dye use (eg. methylene blue or indocyanine green)
• Nail polish or black henna
• Tape or bandages over the fingers
• Absent/inadequate pulse oximetry tracing on existing monitor

All adult surgical patients presenting for elective or emergency surgery within an academic teaching hospital. Patients will have measurements made in the perioperative period in areas where conventional monitoring of pulse oximetery occurs, such as anaesthesia preassessment areas, induction rooms, operating theatres, recovery areas, ICU and PAHCU.

Raw study data will be uploaded to an open sharing platform (www.researchgate.org or similar) after publication of the study.

Upon publication of the study, to remain available indefinitely.

Open access after publication