Pulse Oximetry Readings Research Articles

Inverse linear association between blood haemoglobin and oxygen saturation accuracy measured by pulse oximetry: a cross-sectional analysis in individuals with COVID-19 infection

BackgroundPulse oximetry measures oxygen saturation non-invasively by using differential absorption of infrared signals which are dependent on the oxyhaemoglobin:deoxyhaemoglobin ratio. We tested the hypothesis that pulse oximetry error in measurements...

Automated oxygen administration versus manual control in acute cardiovascular care: a randomised controlled trial.

Oxygen therapy is commonly administered to patients with acute cardiovascular conditions during hospitalisation. Both hypoxaemia and hyperoxia can cause harm, making it essential to maintain oxygen saturation (SpO2) within a target range. Traditionally, oxygen administration is manually controlled by nursing staff, guided by intermittent pulse oximetry readings. This study aimed to compare standard manual oxygen administration with automated oxygen administration (AOA) using the O2matic device. In this randomised controlled trial, 60 patients admitted to a cardiac department with an acute cardiovascular condition requiring oxygen therapy were randomised to either standard care (manual oxygen administration) or AOA via the O2matic device. The primary outcome was the percentage of time spent within the desired SpO2 range (92%-96% or 94%-98%) over 24 hours. Patients had a mean age of 75.8±12.4 years, with an average SpO2 of 93%. Those in the AOA group (n=25) spent significantly more time within the target SpO2 range (median 87.0% vs 60.6%, p<0.001) compared with the standard care group (n=28). Time spent below the desired SpO2 range was significantly lower in the AOA group (7.9% vs 33.6%, p<0.001). No significant differences in time spent above the desired SpO2 range were observed between the two groups. AOA with the O2matic device is superior to standard manual control in maintaining SpO2 within the target range in patients hospitalised with acute cardiovascular conditions. The automated systems significantly reduce the time spent in hypoxaemia without increasing hyperoxia. NCT05452863.

Improving effective coverage of medical-oxygen services for neonates and children in health facilities in Uganda: a before–after intervention study

Medical oxygen services are essential for the care of acutely unwell patients. We aimed to assess the effects of a multilevel, multicomponent health-system intervention on hypoxaemia detection, oxygen therapy, and mortality among neonates and children attending level IV health centres and hospitals in Uganda. For this before-after intervention study, we included children who attended paediatric or neonatal wards of 24 level IV health centres and seven general or regional referral hospitals in the Busoga and North Buganda regions of Uganda between June 1, 2020, and June 30, 2022. All neonates younger than 1 month and children aged 1 month to 14 years were eligible for inclusion. We excluded neonates who were not sick but stayed in the maternity ward for routine postnatal care. The intervention involved clinical training, mentorship, and supportive supervision; provision of pulse oximeters and cylinder-based oxygen sources; biomedical-capacity support; and support to develop and disseminate oxygen supply strategies, oxygen therapy guidelines, and lists of essential oxygen supplies. Trained research assistants extracted individual patient data from case notes using a standardised electronic data collection form. Data were collected on health-facility details, age, sex, clinical signs and symptoms, admission diagnoses, pulse oximetry readings, oxygen therapy details, and final patient outcome. The primary outcome was the proportion of admitted neonates and children with a pulse oximetry oxygen saturation reading documented in their patient case notes on day 1 of health-facility admission (ie, pulse oximetry coverage). We used mixed-effects logistic regression to evaluate the effect of the intervention. We obtained data on 71 997 eligible neonates and children admitted to 31 participating health facilities; the primary analysis included 10 001 patients in the pre-intervention period (ie, June 1 to Oct 30, 2020) and 51 329 patients in the post-intervention period (ie, March 1, 2021, to June 30, 2022). Because 1356 patients had missing data for sex, 4365 (46·7%) of 9347 in the pre-intervention group and 22 831 (46·2%) of 49 410 in the post-intervention group were female; 4982 (53·3%) in the pre-intervention group and 26 579 (53·8%) in the post-intervention group were male. The proportion of neonates and children with pulse oximetry at admission increased from 2365 (23·7%) of 10 001 in the pre-intervention period to 45 029 (87·7%) of 51 328 in the post-intervention period. Adjusted analysis indicated greater likelihood of a patient receiving pulse oximetry during the post-intervention period compared with the pre-intervention period (adjusted odds ratio 40·10, 95% CI 37·38-42·93; p<0·0001). Large-scale improvements in hospital oxygen services are achievable and have the potential to improve clinical outcomes. Governments should be encouraged to develop national oxygen plans and focus investment on interventions that have been shown to be effective, including the introduction of pulse oximetry into routine hospital care and clinical and biomedical mentoring and support. Bill & Melinda Gates Foundation and ELMA Philanthropies. For the Luganda and Lusoga translations of the abstract see Supplementary Materials section.

Effect of positive end expiratory pressure on non-hypoxic apnea time and atelectasis during induction of anesthesia in infant: A randomized controlled trial.

This study aimed to assess the impact of positive-end-expiratory pressure (PEEP) on the non-hypoxic apnea time in infants during anesthesia induction with an inspired oxygen fraction of 0.8. This age stratified randomized controlled trial included patients under 1 year of age. Preoxygenation was performed using an inspired oxygen fraction of 0.8 for 2 min. Inspired oxygen fraction of 0.8 was administered via a face mask with volume-controlled ventilation at a tidal volume of 6 mL.kg-1, with or without 7 cmH2O of PEEP. Tracheal intubation was performed after 3 min of ventilation; however, it was disconnected from the breathing circuit. Ventilation was resumed once the pulse oximetry readings reached 95%. The primary outcome was the non-hypoxic apnea time, defined as the time from the cessation of ventilation to achieving a pulse oximeter reading of 95%. The secondary outcome measures included the degree of atelectasis assessed by ultrasonography and the presence of gastric air insufflation. Eighty-four patients were included in the final analysis. In the positive end-expiratory pressure group, the atelectasis score decreased (17.0 vs. 31.5, p < .001; mean difference and 95% CI of 11.6, 7.5-15.6), while the non-hypoxic apnea time increased (80.1 s vs. 70.6 s, p = .005; mean difference and 95% CI of -9.4, -16.0 to -2.9), compared to the zero end-expiratory pressure group, among infants who are 6 months old or younger, not in those aged older than 6 months. The application of positive end-expiratory pressure reduced the incidence of atelectasis and extended the non-hypoxic apnea time in infants who are 6 months old or younger. However, it did not affect the incidence of atelectasis nor the non-hypoxic apnea time in patients aged older than 6 months.

Below Elbow Amputation Due to Ischemic Complications after Radial Artery Cannulation: A Case Report

The patient is a 57 year old male with peripheral vascular disease and a non-healing thumb wound. After radial artery catheterization (RAC), he developed pain and numbness in the radial-sided 3.5 fingers and pulse oximetry readings &lt;80%. With a possible diagnosis of carpal tunnel syndrome due to increased pressure, the patient underwent a carpal tunnel release (CTR) one week after the catheterization and reported immediate pain relief. Unfortunately, his wound failed to heal, and his pain returned one week later. Another operation was performed to decompress the carpal tunnel; however, the pain worsened, and fingertip necrosis progressed, including the thumb, index, and middle fingers. An angiogram showed arterial calcifications, ruling out reperfusion of the hand. A trans-forearm amputation was performed. This case highlights overlapping symptoms of ischemia and median nerve compression as well as the risk of hand ischemia after RAC in those with circulatory compromise.

Effect of henna application on pulse oximetry reading among sick children admitted in an emergency unit: A single-center prospective observational study from Nigeria

Background: As red henna interferes with the working principles of pulse oximetry, it affects peripheral oxygen saturation readings. This study was conducted to determine the effect of henna on the pulse oximetry of sick children admitted to the emergency department (ED). Subjects and Methods: This was a prospective observational study on 100 sick children admitted to ED. The red henna was applied on the right index finger and right toe, while the left index finger and left toe served as control. SpO2 readings for the upper limbs and lower limbs were recorded simultaneously and compared. Results: The median (interquartile range) age was 4.0 (2.0–8.6) years. There was no significant difference between SpO2 (95.9±4.2 vs. 95.4±4.4) for the upper limb finger (t = 1.147, P = 0.254) and Spo2 (95.3% ±4.9% vs. 95.7% ±3.9%) for lower limb finger (t = 0.954, P = 0.342) with henna and their corresponding pair without henna. However, the SpO2 of children with hypoxia (92.12% ±5.6% vs. 86.88% ±9.6%) for upper limb finger (92.00% ±5.7% vs. 88.41% ±5.5%) and for the toe was significantly higher on digits with henna compared with their pairs without henna (t = 3.167, P = 0.006 upper limb pair; t = 6.351, P = 0.013 for lower limb pair). Conclusions: Red henna application does not significantly affect the reading of pulse oximetry among children without hypoxia but significantly overestimates the oximetry reading in hypoxic children.

Comparison between Portable Pulse Oximeter and Conventional ICU Pulse Oximeter measurements in healthy adults: A Cross Sectional Study

ABSTRACT: Objective: To assess the agreement between oxygen saturation reading between portable pulse oximeter and conventional ICU monitor pulse oximeter. Methods: This cross-sectional study was conducted at Department of Medicine, Fatima Hospital Baqai Medical University, Karachi, from 1st March 2023 to 31st March 2023. Participants in the study in- cluded healthy health care workers and medical students who were over the age of 18 and did not have any known co-morbid conditions like hypertension or diabetes that may affect peripheral perfu- sion. None of the participants had hypotension, clinical evidence of anemia, fingernail paint or poor peripheral perfusion as these are the factors that may influence pulse oximetry readings. Both the portable pulse oximeter and the traditional intensive care unit (ICU) monitors were utilized to take and record the oxygen saturation levels of each of the ten fingers in a sequential manner while the patient was seated. Data was analyzed using SPSS version 22. Readings of both instruments were com- pared employing Regression analysis. Bland-Altman analysis was applied to measure the level of agreement between readings of portable pulse oximeter and conventional ICU monitors. Results: Total 200 participants were enrolled for this study and most of them were from younger age group. (Mean age of participants = 33.05 ± 10.31). There was no significant difference between oxy- gen saturation readings of respective finger from portable pulse oximeter and conventional ICU moni- tors on regression analysis (p &gt; 0.05). Highest mean oxygen saturation was recorded in right middle finger using portable pulse oximeter (98.71 ± 1.21). On the ICU monitor pulse oximeter, it was 2nd highest in right middle finger (98.33 ± 2.49). Therefore, Bold-Altman analysis applied between oxygen saturation reading for two devices in right middle finger and was found to be comparable. (Mean dif- ference (bias) = 0.375 with 95% confidence interval). Conclusion: Modern portable pulse oximeters can reliably be used to rule out hypoxemia.

Post-COVID syndrome and capillary bed abnormalities detected by videocapillaroscopy

Post-COVID syndrome (PCS) is a pressing problem in clinical practice. Dyspnea, along with neurologic and cardiovascular symptoms, is the most common symptom indicating low exercise capacity (EC) that reduces quality of life. The aim of this study was to investigate shortness of breath and the capillary bed abnormalities detected video capillaroscopy (VCS) in patients with PCS.Methods. The study included patients with PCS (n = 60) suffering from shortness of breath. Dyspnea was assessed using the 6-minute walk test (6-MWT). The capillary bed abnormality was diagnosed using VCS.Results. Patients with ACL walked an average of 79.5% of the predicted distance in the 6-MWT. They also had a decrease in pulse oximetry readings. The patients were divided into 2 groups: 1st – patients with desaturation, 2nd – patients without desaturation. Significant differences were observed between patients with and without desaturation, especially in the 6-MWT distance, pulse oximetry, and dyspnea before and after the 6-MWT. Patients with desaturation had a higher desaturation-to-distance ratio, a higher O2-GAP index, and higher cardiac effort levels, as well as a significant decrease in the proportion of perfused capillaries (PPC), mean capillary density, and a marked increase in the proportion of tortuous and branched capillaries. There was a direct correlation between PPC and diffusing lung capacity for carbon monoxide (DLCO), and carbon monoxide transfer coefficient (DLCO/Va), distance traveled during the 6-MWT and percentage (%) of predicted distance, inverse correlation between PPC and cardiac effort. There was a direct correlation between the percentage (%) of capillary recovery and 6-MWT distance and the percentage (%) of predicted distance, as well as an inverse correlation with the ratio of desaturation indicators and walking distance. Similarly, there was a direct correlation between mean capillary density and DLCO/Va, while the proportion (%) of tortuous capillaries was inversely correlated with DLCO, and the proportion (%) of branched capillaries was inversely correlated with DLCO/Va.Conclusion. The multifactorial nature of the mechanisms of dyspnea in patients with PCS was demonstrated, with the important role of vasculopathy. Continuous monitoring of pulse oximetry, heart rate and VCS are effective methods to screen and assess the condition of patients with PCS and dyspnea.

Implication of the 2014 World Health Organization Integrated Management of Childhood Illness Pneumonia Guidelines with and without pulse oximetry use in Malawi: A retrospective cohort study.

Under-5 pneumonia mortality remains high in low-income countries. In 2014 the World Health Organization (WHO) advised that children with chest indrawing pneumonia, but without danger signs or peripheral oxygen saturation (SpO 2) < 90% be treated in the community, rather than hospitalized. In Malawi there is limited pulse oximetry availability. Secondary analysis of 13,413 under-5 pneumonia cases in Malawi. Pneumonia associated case fatality ratios (CFR) were calculated by disease severity under the assumptions of the 2005 and 2014 WHO Integrated Management of Childhood Illness (IMCI) guidelines, with and without pulse oximetry. We investigated if pulse oximetry readings were missing not at random (MNAR). The CFR of patients classified as having non-severe pneumonia per the 2014 IMCI guidelines doubled under the assumption that pulse oximetry was not available (1.5% without pulse oximetry vs 0.7% with pulse oximetry, P<0.001). When 2014 IMCI guidelines were applied with pulse oximetry and a SpO 2 < 90% as the threshold for referral and/or admission, the number of cases meeting hospitalization criteria decreased by 70.3%. Unrecorded pulse oximetry readings were MNAR with an adjusted odds for mortality of 4.9 (3.8, 6.3), similar to that of a SpO 2 < 90%. Although fewer girls were hospitalized, female sex was an independent mortality risk factor. In Malawi, implementation of the 2014 WHO IMCI pneumonia guidelines, without pulse oximetry, will miss high risk cases. Alternatively, implementation of pulse oximetry may result in a large reduction in hospitalization rates without significantly increasing non-severe pneumonia associated CFR if the inability to obtain a pulse oximetry reading is considered a WHO danger sign.

Abstract 104: Photoplethysmogram Signal Characteristics as a Non-Invasive Surrogate of Diastolic Blood Pressure During Cardiopulmonary Resuscitation

Background: During cardiopulmonary resuscitation (CPR), diastolic blood pressure (DBP) is a key driver of coronary perfusion pressure and thereby, blood flow during CPR. Although resuscitation guidelines advise measuring DBP as an indicator of CPR quality, the need for an invasive arterial catheter to measure DBP limits scope of patients for whom a BP-directed CPR strategy can be implemented. Aims and Hypothesis: We aimed to study the photoplethysmogram (PPG) signal acquired from pulse oximetry monitoring as a non-invasive indicator of CPR quality. We hypothesized that a machine learning algorithm using dynamic PPG features would accurately classify CPR segments according to whether they met established pediatric DBP thresholds associated with improved outcomes (≥25mmHg in infants and ≥30 mmHg in older children). Methods/Approach: This was an NHLBI-funded ancillary study of the ICU-RESUScitation clinical trial (NCT02837497). This initial pilot study included 12 children who received CPR for an IHCA and had both arterial BP and pulse oximetry monitoring in place. Physiologic data were summarized into five-second epochs and DBP for each epoch was dichotomized by whether it met age-based DBP thresholds. Time-domain features ( k =25) were systematically engineered from the PPG signal, and a Support Vector Machine (SVM) model with a Gaussian kernel was trained to classify the CPR quality samples. Results: The analysis yielded n= 268 five-second CPR epochs, of which 147 (55.9%) met DBP thresholds. In the testing set of 134 previously unseen samples (50% of n , n low =59, n high =75), the SVM model achieved a classification accuracy of 91% with 100% precision and specificity, 79.7% sensitivity, and a negative predictive value of 86.2% only influenced by false negatives. Throughout development, six features describing the dicrotic notch characteristics reflected in the PPG waveform were empirically observed as significant CPR quality indicators. Conclusion: In this multicenter pilot investigation, the PPG waveform derived from pulse oximetry readings showed promise as a non-invasive surrogate of invasively measured DBP during pediatric CPR. This has the potential to greatly broaden the population for whom physiologic monitoring during CPR is possible.

Assessment of skin pigmentation-related bias in pulse oximetry readings among adults

PurposeRecent reports that pulse oximeters may overestimate oxygen saturation in individuals with darker skin pigmentation have prompted concerns from regulatory authorities regarding racial bias. We investigated the performance of TruSignal SpO2 sensors (GE Healthcare, Helsinki, Finland) in adults with varying skin pigmentation.MethodsA retrospective study was conducted using a set of pooled assessments of SpO2/SaO2 measurements from nine studies to assess bias, accuracy (Arms), and precision of TruSignal sensors in healthy adults under induced hypoxia. Subgroup analyses were performed based on oxygen saturation levels (band 1, ≥ 70 and ≤ 80%; band 2, > 80 and ≤ 90%; band 3, > 90 and ≤ 100%).ResultsOf the 10,800 data points from 131 individuals, 8,202 (75.9%) and 2,598 (24.1%) were assigned to the light and dark pigment groups, respectively. Bias was 0.14% overall and less than 1% across oxygenation bands. The difference in bias between dark and light pigment groups was statistically significant at the low oxygenation band with SpO2 ≥ 70 and ≤ 80% (+ 0.58% and + 0.30% respectively; p = 0.0035). Throughout the saturation range, Arms was 1.64% in the light and 1.71% in the dark pigment group, within device specifications and regulatory requirements. Oxygenation was the dominating factor in stepwise ANOVA modeling. The mixed model also showed that bias was strongly affected by the oxygenation range.ConclusionTruSignal sensors demonstrated higher bias at lower oxygen saturation, with less than 0.5% difference between pigment groups. These findings raise new questions, such as ways to improve pulse oximetry measurements during challenging clinical conditions, including low perfusion.

Evaluating a Novel Infant Heart Rate Detector for Neonatal Resuscitation Efforts: Protocol for a Proof-of-Concept Study.

Over 10 million newborns worldwide undergo resuscitation at birth each year. Pediatricians may use electrocardiogram (ECG), pulse oximetry (PO), and stethoscope in determining heart rate (HR), as HR guides the need for and steps of resuscitation. HR must be obtained quickly and accurately. Unfortunately, the current diagnostic modalities are either too slow, obtaining HR in more than a minute, or inaccurate. With time constraints, a reliable robust heart rate detector (HRD) modality is required. This paper discusses a protocol for conducting a methods-based comparison study to determine the HR accuracy of a novel real-time HRD based on 3D-printed dry-electrode single-lead ECG signals for cost-effective and quick HR determination. The HRD's HR results are compared to either clinical-grade ECG or PO monitors to ensure robustness and accuracy. The purpose of this study is to design and examine the feasibility of a proof-of-concept HRD that quickly obtains HR using biocompatible 3D-printed dry electrodes for single-lead neonatal ECG acquisition. This study uses a novel HRD and compares it to the gold-standard 3-lead clinical ECG or PO in a hospital setting. A cross-sectional study is planned to be conducted in the neonatal intensive care unit or postpartum unit of a large community teaching hospital in Toronto, Canada, from June 2023 to June 2024. In total, 50 newborns will be recruited for this study. The HRD and an ECG or PO monitor will be video recorded using a digital camera concurrently for 3 minutes for each newborn. Hardware-based signal processing and patent-pending embedded algorithm-based HR estimation techniques are applied directly to the raw collected single-lead ECG and displayed on the HRD in real time during video recordings. These data will be annotated and compared to the ECG or PO readings at the same points in time. Accuracy, F1-score, and other statistical metrics will be produced to determine the HRD's feasibility in providing reliable HR. The study is ongoing. The projected end date for data collection is around July 2024. The study will compare the novel patent-pending 3D-printed dry electrode-based HRD's real-time HR estimation techniques with the state-of-the-art clinical-grade ECG or PO monitors for HR accuracy and examines how fast the HRD provides reliable HR. The study will further provide recommendations and important improvements that can be made to implement the HRD for clinical applications, especially in neonatal resuscitation efforts. This work can be seen as a stepping stone in the development of robust dry-electrode single-lead ECG devices for HR estimations in the pediatric population. DERR1-10.2196/45512.

LED light can falsify pulse oximetry readings via the stroboscopic effect

Because of its simplicity, pulse oximetry plays a ubiquitous role in neonatology. Its measurements are based on the absorption of light by hemoglobin. Ambient light can affect these values, therefore algorithms are designed to compensate for constant ambient light. Modern light-emitting diodes often flicker at a very high frequency. Such flickering ambient light can lead to significant measurement errors in saturation. To present a novel way in which light-emitting diodes influence the function of pulse oximeters and to demonstrate mathematically that a stroboscopic effect may well be responsible for this disturbance. Using publicly available data, a mathematical model of a pulse oximeter with a calibration curve and a proprietary measurement algorithm was created. This was used to simulate saturation measurements in flickering ambient light. To do this, photopletysmograms for red and infrared light at 98% oxygen saturation were mathematically superimposed on the light emission from an examination lamp used in the intensive care unit. From these results, presumable saturation measurements from a pulse oximeter were extrapolated. The light-emitting diodes in the examination lamp flicker at 207 Hz. The pulsating light from the light-emitting diodes causes superimposition of the photoplethysmogram due to the stroboscopic effect. With increasing brightness, the saturation dropped to 85% and the pulse rate to 108 bpm. The pulsed light of light-emitting diodes can distort pulse oximetry measurements. The stroboscopic effect leads to low saturation values, which can lead to the risk of blindness in premature infants due to excessive oxygenation.

Comparative Analysis of Oxygen Saturation by Pulse Oximetry and Arterial Blood Gas in Hypoxemic Patients in a Tertiary Care Hospital.

Oxygen saturation is essential for medical care and is closely regulated within the body. Arterial blood gas (ABG) analysis is used to evaluate critically ill individuals' ventilation, oxygenation, acid-base status, and metabolic condition. Pulse oximetry is an easy and non-invasive way to measure the status of oxygen saturation non-invasively in clinical settings and provides a quick and precise assessment of oxygenation and reduces medical errors. SpO2 may not always be a reliable predictor of arterial oxygen saturation (SaO2), and hypoxemic, hemodynamically compromised, and critically ill patients may have lower SpO2 accuracy. A study is needed to assess and compare various oxygen saturation methods. The study aimed to compare the oxygen saturation levels measured by pulse oximetry and ABG analysis in hypoxemic patients. The objectives were tocompare the values between SaO2, PaO2, and SpO2 values obtained from the patients, and correlate the study parameters among both techniques. The study was conducted from February 2021 to June 2022 among the 102 hypoxemic patients who were admitted to the emergency and surgical intensive care unit (ICU) of Sree Balaji Medical College and Hospital in Chennai. Primary data on ABGanalysis and pulse oximetry readings were collected from the study subjects. The patient and their past medical records, physical exam, chest x-ray findings, pulse oximetry, and ABG results were all reviewed. Each patient had their ABG, and pulse oximetry measured simultaneously. A comparison was made between SpO2 and partial pressure of oxygen (PaO2) and arterial oxygen saturation (SaO2) parameters using a paired t-test. The correlation was done against the SpO2 and ABG parameters and assessed for association using the correlation coefficient value; gender was also considered while correlating. An observational study was done among 102 study samples to comparatively analyze the oxygen saturation by two methods, namely pulse oximetry and ABG, in hypoxemic patients. While comparing the mean values of SaO2 and SpO2, they were 84.41 ± 4.24 and 80.58 ± 5.77, respectively, and this difference was statistically very significant (p< 0.001). While comparing the mean values of PaO2 and SaO2, they were 61.02 ± 5.01 and 84.41 ± 4.24, respectively, and this difference was statistically significant (p = 0.043). While comparing the mean values of PaO2 and SpO2, they were 61.02 ± 5.01 and 80.58 ± 5.77, respectively, and this difference was statistically significant (p = 0.054). Among the study population, with regard to the correlation factor, there is notably a very high and strong positive correlation between SaO2 and SpO2 and between SpO2 and PaO2. There was a negative correlation between SpO2 and finger abnormalities and between SpO2 and blood pressure. The ABGmethod is considered the gold standard. When SpO2 levels fall below 90%, pulse oximetry may not be accurate enough to reliably assess oxygenation. In such cases, where alveolar hypoventilation is suspected, it is recommended to complement pulse oximetry with ABG studies. This is because ABG analysis provides a more comprehensive assessment of oxygenation and acid-base status, which can aid in the diagnosis and management of respiratory conditions.

Implication of the 2014 World Health Organization Integrated Management of Childhood Illness Pneumonia Guidelines with and without pulse oximetry use in Malawi: A retrospective cohort study

Background: Under-5 pneumonia mortality remains high in low-income countries. In 2014 the World Health Organization (WHO) advised that children with chest indrawing pneumonia, but without danger signs or peripheral oxygen saturation (SpO2) &lt; 90% be treated in the community, rather than hospitalized. In Malawi there is limited pulse oximetry availability. Methods: Secondary analysis of 13,413 under-5 pneumonia cases in Malawi. Pneumonia associated case fatality ratios (CFR) were calculated by disease severity under the assumptions of the 2005 and 2014 WHO Integrated Management of Childhood Illness (IMCI) guidelines, with and without pulse oximetry. We investigated if pulse oximetry readings were missing not at random (MNAR). Results: The CFR of patients classified as having non-severe pneumonia per the 2014 IMCI guidelines doubled under the assumption that pulse oximetry was not available (1.5% without pulse oximetry vs 0.7% with pulse oximetry, P&lt;0.001). When 2014 IMCI guidelines were applied with pulse oximetry and a SpO2 &lt; 90% as the threshold for referral and/or admission, the number of cases meeting hospitalization criteria decreased by 70.3%. Unrecorded pulse oximetry readings were MNAR with an adjusted odds for mortality of 4.9 (3.8, 6.3), similar to that of a SpO2 &lt; 90%. Although fewer girls were hospitalized, female sex was an independent mortality risk factor. Conclusions: In Malawi, implementation of the 2014 WHO IMCI pneumonia guidelines, without pulse oximetry, will miss high risk cases. Alternatively, implementation of pulse oximetry may result in a large reduction in hospitalization rates without significantly increasing non-severe pneumonia associated CFR if the inability to obtain a pulse oximetry reading is considered a WHO danger sign.

Retrospective evaluation of the impact of hypoxemia during thoracic surgery in dogs on outcome: a multicenter analysis of 94 cases

ObjectiveTo investigate the statistical association of severe intraoperative hypoxemia in thoracic surgery with mortality, postoperative hospitalization times and cost of care. Study designRetrospective study. AnimalsDogs that underwent thoracic surgery in three veterinary hospitals between October 1, 2018 and October 1, 2020. MethodsAnesthesia and hospitalization records from 112 dogs were reviewed and 94 cases met inclusion criteria. Recorded data included signalment, disease etiology, pulmonary or extrapulmonary nature of disease, surgical procedure performed, episodes of severe intraoperative hypoxemia defined as a pulse oximetry reading (SpO2) <90% of 5 minutes or longer duration, survival to discharge, time from extubation to hospital discharge and total invoice cost for clinical visit. Dogs were divided into two groups, those that experienced severe hypoxemia (group A) and those in which SpO2 reading <90% was not observed throughout the procedure (group B). ResultsGroup A had a greater risk of mortality (odds ratio 10.6, 95% confidence interval 1.9–106.7; p = 0.002), prolonged hospitalization (median 62 hours versus 46 hours; p = 0.035) and more expensive cost of care (median US$10,287 versus $8506; p = 0.056) than group B. No significant difference was found for the type of surgical procedure or pulmonary versus extrapulmonary nature of disease. Conclusions and clinical relevanceSevere intraoperative hypoxemia was statistically associated with an increased risk of mortality and longer postoperative hospitalization times. Although not achieving statistical significance, there was a trend toward increased costs to the client for animals with intraoperative hypoxemia.

Intraoperative Fraction of Inspired Oxygen and Lung Injury in Coronary Artery Bypass Grafting: Study Protocol for a Randomised Controlled Trial.

Postoperative pulmonary complications are a series of disorders that can contribute to respiratory distress and prolonged mechanical ventilation postoperatively. We hypothesise that a liberal oxygenation strategy during cardiac surgery leads to a higher incidence of postoperative pulmonary complications than a restrictive oxygenation strategy. This study is a prospective, observer-blinded, centrally randomised and controlled, international multicentre clinical trial. After obtaining a written informed consent, 200 adult patients undergoing coronary artery bypass grafting will be enrolled and randomised to receive either restrictive or liberal oxygenation perioperatively. The liberal oxygenation group will receive 1.0 fraction of inspired oxygen throughout the intraoperative period, including during cardiopulmonary bypass. The restrictive oxygenation group will receive the lowest fraction of inspired oxygen required to maintain arterial partial pressure of oxygen between 100 and 150 mmHg during cardiopulmonary bypass and a pulse oximetry reading of 95% or greater intraoperatively, but no less than 0.3 and not higher than 0.80 (other than induction and when the oxygenation goals cannot be reached). When patients are transferred to the intensive care unit, all patients will receive an initial fraction of inspired oxygen of 0.5, and then fraction of inspired oxygen will be titrated to maintain a pulse oximetry reading of 95% or greater until extubation. The lowest postoperative arterial partial pressure of oxygen/fraction of inspired oxygen within 48 hours of intensive care unit admission will be the primary outcome. Postoperative pulmonary complications, length of mechanical ventilation, intensive care unit stay, hospital stay, and 7-day mortality after cardiac surgery will be analysed as secondary outcomes. This is one of the first randomised controlled observer-blinded trials that prospectively evaluates the influence of higher inspired oxygen fractions on early postoperative respiratory and oxygenation outcomes in cardiac surgery patients using cardiopulmonary bypass.

Counterpoint: The value of including patients in prerounding.

Counterpoint: The value of including patients in prerounding.

Factors associated with prolonged postoperative length of hospital stay after laparoscopic colorectal cancer resection: a secondary analysis of a randomized controlled trial

BackgroundThe postoperative length of hospital stay (PLOS) is an important indicator of surgical quality. We identified perioperative factors that affect prolonged PLOS (PPLOS) after laparoscopic colorectal cancer resection, which is the preferred surgical approach for colorectal cancer, the third most common cancer.MethodsThis study was a secondary analysis of a randomized trial (clinicaltrials.gov ID: NCT03160144) that included 280 patients who underwent laparoscopic colorectal cancer resection. The primary outcome was a PPLOS, defined as a PLOS that was longer than the median PLOS. Baseline, anesthetic, surgical, and postoperative management factors were included in the univariate and multivariate analyses to identify factors influencing PPLOS.ResultsThe median PLOS was 10 days, and 117 patients had a PPLOS. We identified six influencing factors for PPLOS: preoperative pulse oxygen saturation < 96% (odds ratio [OR], 3.09 [95% confidence interval (CI) 1.38–6.92]; P = 0.006), distant tumor metastasis (OR, 0.34 [95% CI 0.13–0.91]; P = 0.031), the Miles procedure or left hemicolectomy (OR, 4.51 [95% CI 1.67–12.18]; P = 0.003), perioperative surgical events (OR, 2.44 [95% CI 1.25–4.76]; P = 0.009), postoperative albumin infusion (OR, 2.19 [95% CI 1.14–4.19]; P = 0.018), and postoperative early ambulation (OR, 0.35 [95% CI 0.18–0.68]; P = 0.002). Further stratified analysis showed that postoperative albumin infusion might be a risk factor for PPLOS, even in patients with a preoperative albumin level < 40 g/L (OR, 2.29 [95% CI 0.98–5.34]; P = 0.056) or duration of surgery ≥ 3 h (OR, 2.52 [95% CI 1.08–5.87]; P = 0.032).ConclusionsA low preoperative pulse oximetry reading, complex surgical procedures, perioperative surgical events, and postoperative albumin infusion may be risk factors for PPLOS after laparoscopic colorectal cancer resection, whereas distant tumor metastasis and postoperative early ambulation might be protective factors. The association between postoperative albumin infusion, a modifiable factor, and PLOS or clinical outcomes warrants further investigation.

Reference values for babies' pulse oximetry recordings, highlighting the impact of cesarean sections and COVID-19 pandemic

Background: With a focus on the consequences of caesarean delivery as a result of mother stress and the first wave of the COVID-19 epidemic as a source of maternal stress, the study sought to identify reference values for pulse oximetry recordings among both healthy full-term neonates and preterm and unhealthy neonates.Methods: A comparative study of 170 neonates admitted to the Fayoum university NICU after being born in the department of obstetrics and gynaecology. Collected pulse oximetry readings at predetermined intervals was done. Patients were classified into group I (before 1st wave of COVID-19 pandemic) and group II (during 1st wave of COVID-19 pandemic).Results: The 5th and 95th percentiles of SpO2 after 1 minute after birth were (65% to 90%), with a mean of 77%, according to the study of 146 full-term healthy newborns. SpO2 readings were (89% to 97.1%) with a mean of 92% after 5 minutes, and finally (90% to 98%) with a mean of 93% after 10 minutes. Statistically significant lower means of SpO2 were found during 1st wave of COVID-19 pandemic after 10 minutes of delivery, and for Apgar score after 1 and 5 minutes of delivery. There was a negative impact of cesarean section delivery on gestational age.Conclusions: This research reveals that after 10 minutes of delivery, a Spo2 recorded range of 90 to 98 for full-term healthy neonates and a mean of 86% for preterm and ill neonates may be appropriate. The first wave of the COVID-19 pandemic had a deleterious impact on neonates' SpO2 recordings and Apgar scores, according to the study. There was a gestational age effect associated with caesarean delivery.