Can we improve the prescribing and delivery of oxygen on a respiratory ward in accordance with new British Thoracic Society oxygen guidelines?

Association between SpO2 and the risk of death in elderly T2DM patients with cerebral infarction: a retrospective cohort study

Objective

This study aimed to evaluate the SpO2 (transcutaneous oxygen saturation) -mortality link in elderly T2DM (diabetes mellitus type 2) patients with cerebral infarction and identify their optimal SpO2 range.

Methods

In this investigation, we employed a comprehensive approach. Initially, we screened the MIMIC-IV database, identifying elderly T2DM patients with cerebral infarction, utilizing specific ICD-9 and ICD-10 codes. We then harnessed the power of restricted cubic splines to craft a visual representation of the correlation between SpO2 and 1-year mortality. To enhance our analysis, we harnessed Cox multivariate regression, allowing us to compute adjusted hazard ratios (HR) accompanied by 95% confidence intervals (CIs). Additionally, we crafted Cumulative Mortality Curve analyses, augmenting our study by engaging in rigorous subgroup analyses, stratifying our observations based on pertinent covariates.

Results

In this study, 448 elderly T2DM patients with cerebral infarction were included. Within 1-year post-discharge, 161 patients (35.94%) succumbed. Employing Restricted Cubic Spline analysis, a statistically significant U-shaped non-linear relationship between admission ICU SpO2 levels and 1-year mortality was observed (P-value < 0.05). Further analysis indicated that both low and high SpO2 levels increased the mortality risk. Cox multivariate regression analysis, adjusting for potential confounding factors, confirmed the association of low (≤94.5%) and high SpO2 levels (96.5-98.5%) with elevated 1-year mortality risk, particularly notably high SpO2 levels (>98.5%) [HR = 2.06, 95% CI: 1.29-3.29, P-value = 0.002]. The cumulative mortality curves revealed the following SpO2 subgroups from high to low cumulative mortality at the 365th day: normal levels (94.5% < SpO2 ≤ 96.5%), low levels (SpO2 ≤ 94.5%), high levels (96.5% < SpO2 ≤ 98.5%), and notably high levels (>98.5%). Subgroup analysis demonstrated no significant interaction between SpO2 and grouping variables, including Sex, Age, Congestive heart failure, Temperature, and ICU length of stay (LOS-ICU; P-values for interaction were >0.05).

Conclusions

Striking an optimal balance is paramount, as fixating solely on lower SpO2 limits or neglecting high SpO2 levels may contribute to increased mortality rates. To mitigate mortality risk in elderly T2DM patients with cerebral infarction, we recommend maintaining SpO2 levels within the range of 94.5-96.5%.

Association between transcutaneous oxygen saturation within 24 h of admission and mortality in critically ill patients with non-traumatic subarachnoid hemorrhage: a retrospective analysis of the MIMIC-IV database

Background

In critically ill patients, transcutaneous oxygen saturation (SpO2) upon admission is typically associated with in-hospital mortality. Nevertheless, the available information for patients with non-traumatic subarachnoid hemorrhage (SAH) is limited. In our study, our objective was to assess the correlation between SpO2 levels and mortality among patients diagnosed with severe SAH.

Methods

In this study, we extracted data from the Medical Information Marketplace in Intensive Care (MIMIC-IV) database, which comprises information on critically ill patients. By employing matching ICD-9 and ICD-10 codes, we identified 3,328 patients diagnosed with SAH. Every individual who was admitted to the intensive care unit (ICU) had their SpO2 data and various covariates, including age, sex, diagnosis, and duration of stay, recorded upon admission. Subsequently, the patients were categorized into three distinct groups according to their SpO2 levels: low (≤95%), moderate (95-98%), and high (≥98%). To investigate the association between percutaneous oxygen saturation and mortality in patients with severe SAH, logistic regression, and cubic spline models were utilized. The main outcomes of interest were 28- and 90-day mortality rates. Additionally, subgroup analyses were conducted to evaluate these correlations and assess the consistency of interactions.

Results

A cohort of 864 patients diagnosed with non-traumatic SAH was included in this study. The correlation between SpO2 and mortality displayed a U-shaped curve when utilizing a finite cubic spline function (non-linearity < 0.001), with the nadir in the probability of in-hospital death at 96%. Mortality at 28 and 90 days showed an inverse correlation with SpO2 < 96% (adjusted odds ratio [OR], 0.8; 95% confidence interval [CI], 0.67-0.95, and 0.76; 95% CI, 0.6-0.96). Conversely, there was a positive correlation between percutaneous oxygen saturation (SpO2) levels of ≥96% and mortality rates at both 28 and 90 days (adjusted OR, 1.17; 95% CI, 1.02-1.35 and 1.2; 95% CI, 1.05-1.39).

Conclusion

In patients with severe subarachnoid hemorrhage, the association between SpO2 and mortality at 28 and 90 days demonstrated a U-shaped pattern. When SpO2 levels were between 95 and 98%, both short- and long-term mortality rates were at their lowest. Patients with significant subarachnoid hemorrhage had a lower chance of survival when their SpO2 values were either high or low.

Reducing inappropriate oxygen use in hospitalized medicine patients

INTRODUCTION

Evidence suggests inappropriate oxygenation may be harmful to patients. To improve oxygen use in our hospital, we initiated a quality improvement project with a goal to reduce the percentage of inappropriate utilization of oxygen by 50% within a year.

METHODS

Nasal cannula (NC) oxygen use data for medicine inpatients was abstracted weekly for chart review. A multidisciplinary team developed a guideline for use. Initiation of NC O2 with a baseline SPO2 > 92% was deemed inappropriate and 3+ consecutive SPO2 > 96% was defined as over-supplementation. Formal interventions included an oxygen use guideline, updated EMR order, unit-specific feedback, and magnetic placards. Progress was tracked by control charts.

RESULTS

Baseline data revealed 40% of patients were inappropriately placed on oxygen and 55% of patients had one instance of excessive supplementation. Only half of all improper uses of oxygen had charted medical reasoning, and 30% had a corresponding order. Instances of proper oxygen use had orders 48% of the time. Run charts revealed inappropriate initiation was significantly reduced to 27.1% (p < 0.0001) and excessive oxygenation decreased significantly to 34.4% (p < 0.0001) following interventions with no effect on other variables.

CONCLUSIONS

Our interventions significantly decreased improper oxygen initiation and excessive supplementation.

In-hospital mortality and SpO2 incritical care patients with cerebral injury: data from the MIMIC‑IV Database

BACKGROUND

Evidence regarding the relationship between in-hospital mortality and SpO2 was low oxygen saturations are often thought to be harmful, new research in patients with brain damage has found that high oxygen saturation actually enhances mortality. However, there is currently no clear study to point out the appropriate range for oxygen saturation in patients with craniocerebral diseases.  METHODS: By screening all patients in the MIMIC IV database, 3823 patients with craniocerebral diseases (according to ICD-9 codes and ICD-10) were selected, and non-linear regression was used to analyze the relationship between in-hospital mortality and oxygen saturation. Covariates for all patients included age, weight, diagnosis, duration of ICU stay, duration of oxygen therapy, etc. RESULTS: In-hospital mortality in patients with TBI and SAH was kept to a minimum when oxygen saturation was in the 94-96 range. And in all patients, the relationship between oxygen saturation and in-hospital mortality was U-shaped. Subgroup analysis of the relationship between oxygen saturation and mortality in patients with metabolic encephalopathy and other encephalopathy also draws similar conclusions In-hospital mortality and oxygen saturation were all U-shaped in patients with subarachnoid hemorrhage, metabolic and toxic encephalopathy, cerebral infarction, and other encephalopathy, but the nonlinear regression was statistically significant only in patients with cerebral infarction (p for nonlinearity = 0.002).

CONCLUSION

Focusing too much on the lower limit of oxygen saturation and ignoring too high oxygen saturation can also lead to increase in-hospital mortality. For patients with TBI and SAH, maintaining oxygen saturation at 94-96% will minimize the in-hospital mortality of patients.

Increasing oxygen prescribing during the COVID-19 pandemic

Valid oxygen prescriptions for hospital inpatients have been a long-standing problem and have been described extensively in BMJ Open Quality with numerous quality improvement projects (QIPs) with the aim of improving compliance with oxygen prescribing.The British Thoracic Society recommends that all inpatients should have oxygen target saturation set on admission: this is motivated by risks of both undertreatment and overtreatment with oxygen. The discrepancy between the recommendation and the reality produced a number of interventions studied in QIPs over the past years, all aiming at bringing the local ward teams closer to the target. This has become even more important during the COVID-19 pandemic, where non-standard oxygen saturation targets and oxygen scarcity led hospital systems to rethink their internal guidelines on the subject.We propose three novel interventions to improve compliance: a remote, personally directed email communication to a ward pharmacist, a similar communication to ward nurses, and a remote, personally directed WhatsApp communication to junior ward doctors. We undertake a QIP which compares novel interventions developed in-house with the most successful interventions from oxygen prescribing initiatives that have previously been published by BMJ Open Quality The main outcome measure was the proportion of patients with valid oxygen prescription on a ward.The series of novel interventions in three plan, do study, act cycles led to improvement in the outcome measure from 0% at baseline to 70% at the end of the QIP. The successful interventions from previous QIPs were ran in parallel on a similar ward and achieved improvement from 17.9% at baseline to 55.6% at the end of the QIP.This QIP demonstrates adapted interventions performed in context of social distancing aimed at members of multidisciplinary team which achieve superiority in increasing proportion of patients with a valid oxygen prescription, when compared with previously described methods from BMJ Open Quality.

Improving documentation of prescriptions for as-required medications in hospital inpatients

It is estimated that 1 in 10 hospital inpatients in Scotland have experienced a medication error. In our unit, an audit in 2019 identified documentation of as-required prescriptions on drug Kardexes as an important target for improvement. This project aimed to reduce the percentage of these errors to <5% in the ward in 6 months.Weekly point prevalence surveys were used to measure medication error rates over a 12-week baseline period. Errors in route, frequency of dose and maximum dose accounted for >80% of all prescribing errors. The intervention was a poster reminder about the three most common errors linked to standards for prescribing pain medication. Barriers to change were identified through inductive thematic analysis of semistructured interviews with five ward doctors and two staff nurses.In the 6 weeks after intervention, our run chart showed a shift in maximum dose errors per patient, which fell from 75% to 26%. However, route and frequency errors remained high at >70% per patient. Most of these errors were due to use of abbreviations, and qualitative interviews revealed that senior doctors and nurses believed that these abbreviations were safe. We found some evidence from national guidelines to support these beliefs.Overall, the intervention was associated with decreased prevalence of patients without a maximum dose written on their prescription, but lack of space on drug prescriptions was identified as a key barrier to further improvement in both maximum dose and abbreviation errors.

Rationalising oxygen usage in a level II special newborn care unit in Madhya Pradesh, India

Non-judicious oxygen use in preterm infants is associated with increased risk of retinopathy of prematurity, bronchopulmonary dysplasia and longer hospital stay. Despite established guidelines on oxygen therapy, compliance with the best oxygen practices remains suboptimal. Excessive use of oxygen also consumes a large proportion of the annual maintenance budget of special newborn care units (SNCUs) in the districts. In this project, we aimed to reduce the oxygen consumption in the SNCU at Sehore, Madhya Pradesh, India from eight to four cylinders per day, by rationalising the indications, monitoring and method of oxygen delivery.

We tested two sets of interventions using the Plan–Do–Study–Act (PDSA) approach. The first intervention was the introduction of a written ‘oxygen policy’ regarding indications of starting/stopping oxygen and the use of saturation targets. The second was using short binasal infant prongs (at 0.5–1 L/min), instead of oxygen hoods as the primary method of oxygen delivery in spontaneously breathing neonates requiring oxygen. In the first PDSA cycle, we assessed the feasibility of the intervention in a small set (n=30) of neonates and later scaled up to all eligible neonates in the second phase.

We observed a significant reduction in oxygen consumption (from median (IQR) 8 (7–8) to 3 (3–4) cylinders per day) that can lead to a direct saving of 590 000 Indian rupees (US$9000) per year. There was a significant reduction in the number of neonates on oxygen support on a given day. We did not observe any increase in mortality or nasal injury. The change was sustained for the next 8 months.

We conclude that by having a contextual oxygen policy and using nasal prongs instead of oxygen hoods as the preferred delivery method, we can achieve a sustainable reduction in oxygen consumption.

Audit of oxygen administration to achieve a target oxygen saturation range in acutely unwell medical patients

PURPOSE OF THE STUDY

To evaluate documentation of a target oxygen saturation (SpO₂) range and ability to achieve this range in acutely unwell inpatients.

STUDY DESIGN

In this single-centre audit, patients with discharge diagnoses of pneumonia, heart failure and exacerbation of asthma or COPD admitted to Wellington Regional Hospital, New Zealand between 1 June 2019 and 31 August 2019 who received oxygen were identified. In those with a documented target SpO₂ range, the proportion of SpO₂ measurements in the observation chart which were within, above and below range were determined as well as the maximum and minimum SpO₂. Regression analysis was performed to determine whether these outcomes were influenced by the prescribed range, high-dependency care or the number of adjustments to oxygen administration.

RESULTS

268 admissions were screened. Of the 100 eligible admissions who received oxygen, a target SpO₂ range was documented in 62. The mean (SD) proportion of SpO₂ measurements within range was 56.2 (30.6)%. A hypercapnic target SpO₂ range was associated with a higher probability of an SpO₂ above range; multivariate OR 5.34 (95% CI 1.65 to 17.3, p=0.006) and a lower probability of an SpO₂ below range; multivariate OR 0.25 (95% CI 0.08 to 0.80) p=0.02. The mean (SD) maximum SpO₂ was similar in those with a target range of 92%-96% versus a hypercapnic range; 96.2 (3.0)% and 95.2 (3.4)%, respectively.

CONCLUSIONS

Oxygen prescription and delivery in this clinical setting was suboptimal. SpO₂ values above the designated range are common, particularly in patients with a hypercapnic target range.

Acute oxygen therapy: a cross-sectional study of prescribing practices at an English hospital immediately before COVID-19 pandemic

BACKGROUND

Approximately 14% of UK hospital in-patients receive supplemental oxygen therapy, only 57% have valid prescriptions. Oxygen must be optimally prescribed to ensure maximal therapeutic response whilst minimizing adverse outcomes (including fatality). This study investigates prescription compliance.

METHODS

All adults admitted to medical wards (18 February to 3 March 2020) were included. Analyses present proportions, descriptive statistics, and hypothesis testing. Ethical approval was unnecessary for this audit.

RESULTS

Of the 636 patients admitted, 66 (10%) were receiving oxygen therapy. Ages ranged from 34 to 100 years with 36 (54.5%) males and 30 (45.5%) females. The prescription was not documented in the oxygen section of the drug chart (n = 37, 56.1%, p = 0.389), nor did it have the physicians signature (n = 40, 60.6%, p = 0.110) nor date (n = 46, 69.7%, p = 0.002). Thirteen chronic obstructive pulmonary disease (COPD) patients (19.7%) were at risk of hypercapnic failure (p = 1.582x10^-6). Target oxygen saturation (SpO2) range had been documented for 30 (45.5%) patients. A target SpO2 range of 88-92% was documented for 9 patients (13.6%), a 94-98% range documented for 11 patients (16.7%). All patients had an invalid prescription.

CONCLUSION

We present real-world practice in naturalistic settings, immediately before pandemic-lockdown. Enhanced compliance is advocated to reduce risks of harm and mortality.

The Search for Optimal Oxygen Saturation Targets in Critically Ill Patients: Observational Data From Large ICU Databases

BACKGROUND

Although low oxygen saturations are generally regarded as deleterious, recent studies in ICU patients have shown that a liberal oxygen strategy increases mortality. However, the optimal oxygen saturation target remains unclear. The goal of this study was to determine the optimal range by using real-world data.

METHODS

Replicate retrospective analyses were conducted of two electronic medical record databases: the eICU Collaborative Research Database (eICU-CRD) and the Medical Information Mart for Intensive Care III database (MIMIC). Only patients with at least 48 h of oxygen therapy were included. Nonlinear regression was used to analyze the association between median pulse oximetry-derived oxygen saturation (Spo₂) and hospital mortality. We derived an optimal range of Spo₂ and analyzed the association between the percentage of time within the optimal range of Spo₂ and hospital mortality. All models adjusted for age, BMI, sex, and Sequential Organ Failure Assessment score. Subgroup analyses included ICU types, main diagnosis, and comorbidities.

RESULTS

The analysis identified 26,723 patients from eICU-CRD and 8,564 patients from MIMIC. The optimal range of Spo₂ was 94% to 98% in both databases. The percentage of time patients were within the optimal range of Spo₂ was associated with decreased hospital mortality (OR of 80% vs 40% of the measurements within the optimal range, 0.42 [95% CI, 0.40-0.43] for eICU-CRD and 0.53 [95% CI, 0.50-0.55] for MIMIC). This association was consistent across subgroup analyses.

CONCLUSIONS

The optimal range of Spo₂ was 94% to 98% and should inform future trials of oxygen therapy.