ABSTRACT
Pulse oximetry utilises the differential absorption, by both oxy- and deoxyhaemoglobin, of a light signal passing through tissue to provide a measure of blood oxygen saturation. Although pulse oximetry devices are widely used to monitor patients in real time, and to provide an estimate of risk of deterioration, no studies exist on the association of haemoglobin levels and pulse oximetry measurement error. We examined the effect of different haemoglobin levels on pulse oximetry measurements in patients admitted to a large UK teaching hospital from 1 February 2020 to 31 December 2021 with a possible diagnosis of Covid-19 infection. Pulse oximetry and arterial blood gas oxygen saturations were compared. Two measures of blood haemoglobin levels were available;from a venous sample within 24 hours of the arterial blood gas sampling and directly from the arterial blood gas sample itself. Data were available from 1086 patients. Using the measurement of haemoglobin from the venous blood sample within 24 hours of the blood gas, there was an inverse linear association between haemoglobin and pulse oximetry measurement error of -0.06% per 1 g/L increase of haemoglobin (95% confidence intervals CI: -0.02 to -0.09). This equates to patients with a venous haemoglobin of 70g/L having a measurement error of +8.0% (95% CI: +5.9% to +10.0%) and those with a haemoglobin of 150g/L having a measurement error of +3.6% (95% CI: +2.2% to +4.9%). Similar associations were observed using arterial haemoglobin values. The association between haemoglobin and measurement error of oxygen saturation as determined by pulse oximetry is inverse and linear. It is relatively large in patients with anaemia and may affect clincial assessment.
ABSTRACT
BACKGROUND: COVID-19 was declared a pandemic by the World Health Organization on March 11th, 2020. Global social lockdowns were instigated to reduce spread and prevent health-services from becoming overwhelmed. People having treatment for cancer are known to have heightened psychological/emotional burden. The combined impact of managing pandemic regulations alongside this may present additional burden. The purpose of this systematic review is to examine current evidence of the psychological and emotional impact of COVID-19 on people with cancer, early in the pandemic. METHODS: Five electronic databases were searched (Embase, Global Health, HMIC, PsychINFO, CINAHL) from September 2019 to October 2021. Qualitative, quantitative and mixed-method primary research studies exploring emotional and psychological impacts of COVID-19 on cancer patients, limited to English language, were included. Quality appraisal was conducted using the MMAT. RESULTS: Fifty-one papers, with 27,356 people from 21 countries treated for cancer, were included. 43 studies were quantitative with a survey method approach, six studies qualitative and four used a mixed methods design. MMAT score was mostly two or three. Four themes were identified: Emotional aspects and Quality of Life; Psychosocial aspects; Impact of COVID-19 on self; Impact of COVID-19 on cancer, with themes overlapping. CONCLUSION: Whilst emotional/psychological impacts such as anxiety, isolation, employment fears, and uncertainty about the future were potentially universal concerns early in the pandemic, they may have been particularly acute for people living with cancer and represent complex, overlapping factors. As COVID-19 continues to impact health-services and society, it is important to focus on any ongoing impact to the experience of cancer patients. Most of the studies reviewed used tools that do not provide deeper understanding of how and why emotional states of people with cancer were affected. Further qualitative work may reveal patterns of what was unique to cancer patients during the pandemic, compared to general populations.