Automated audit of hospital oxygen use devised during the COVID-19 pandemic.

BACKGROUND: The British Thoracic Society (BTS) has organised intermittent audits of hospital oxygen use in UK hospitals since 2008. Manual audits are time-consuming and subject to human errors. Oxygen prescribing and bedside observations including National Early Warning Scores (NEWS2 scores) are undertaken within an integrated electronic medical record (EMR) at this hospital. METHODS: The hospital's Business Information team were commissioned in late 2019 to devise a bespoke automated audit of oxygen prescribing and use. A summary report displays the oxygen saturation alongside the oxygen prescription status of every patient in the hospital except for critical care units which do not use NEWS2. The display has a 'traffic-light' colour scheme (green within target range, amber or red if below range or if above range on supplemental oxygen), with a graph showing oxygen use and saturation levels for patients with each prescribed target range. Clinicians can access raw data including oxygen saturation, oxygen device and flow rate for each individual patient. RESULTS: Over 51 audits involving 34 352 sets of observations, an average of 6.0% involved use of oxygen and 88.6% of these had a valid oxygen prescription. During the first wave of the COVID-19 pandemic in spring 2020, the monthly percentage of observations involving oxygen use increased to a peak of 10.4% followed by a rise to 10.6% during the second wave and 7.4% during the third (Omicron) wave. Oxygen use returned to baseline after each wave. CONCLUSIONS: In hospitals with integrated EMRs, it is possible to automate all fundamental aspects of the BTS oxygen audits and to monitor oxygen use at individual patient level and a hospital-wide level. This could be particularly valuable during major events such as the COVID-19 pandemic. This methodology could be extended to other clinical audits where the audit questions relate to routinely collected EMR data.

Carcinoid heart disease of gonadal primary presenting with hypoxia: a case report.

BACKGROUND: Carcinoid heart disease is a potential sequela of metastatic neuroendocrine tumour that has characteristic valve appearances. Patients can present with symptoms of carcinoid syndrome or be relatively asymptomatic until symptoms of progressive heart failure manifest. CASE SUMMARY: We present a case of a 54-year-old male who was admitted to the hospital for investigation of hypoxia. Transthoracic echocardiogram was suggestive of carcinoid heart disease which subsequently led to a diagnosis of metastatic neuroendocrine (carcinoid) tumour of the testicular primary. Work-up revealed a patent foramen ovale with evidence of the right to left interatrial shunt from severe tricuspid regurgitation as the cause of his hypoxia. Prior to surgical excision of the primary tumour, percutaneous patent foramen ovale closure was performed resulting in improved arterial oxygen saturation and symptomatic improvement. DISCUSSION: Carcinoid heart disease typically affects the right-sided cardiac valves and the tricuspid valve appearances were critical in leading to a diagnosis of a metastatic neuroendocrine tumour in our patient. This case demonstrates that percutaneous patent foramen ovale closure can be an effective intervention for hypoxia in those not managed surgically. A high index of suspicion should be maintained for gonadal primary carcinoid tumour when there is carcinoid heart disease in the absence of liver metastases.

Implementing target range oxygen in critical care: A quality improvement pilot study.

BACKGROUND: Iatrogenic hyperoxaemia is common on critical care units and has been associated with increased mortality. We commenced a quality improvement pilot study to analyse the views and practice of critical care staff regarding oxygen therapy and to change practice to ensure that all patients have a prescribed target oxygen saturation range. METHODS: A baseline measurement of oxygen target range prescribing was undertaken alongside a survey of staff attitudes. We then commenced a programme of change, widely promoting an agreed oxygen target range prescribing policy. The analyses of target range prescribing and staff survey were repeated four to five months later. RESULTS: Thirty-three staff members completed the baseline survey, compared to 29 in the follow-up survey. There was no discernible change in staff attitudes towards oxygen target range prescribing. Fifty-four patients were included in the baseline survey and 124 patients were assessed post implementation of changes. The proportion of patients with an oxygen prescription with a target range improved from 85% to 95% (χ2 = 5.17, p = 0.02) and the proportion of patients with an appropriate prescribed target saturation range increased from 85% to 91% (χ2 = 1.4, p = 0.24). The improvement in target range prescribing was maintained at 96% 12 months later. CONCLUSIONS: The introduction and promotion of a structured protocol for oxygen prescribing were associated with a sustained increase in the proportion of patients with a prescribed oxygen target range on this unit.

A feasibility randomised controlled trial of targeted oxygen therapy in mechanically ventilated critically ill patients.

BACKGROUND: Despite oxygen being the commonest drug administered to critically ill patients we do not know which oxygen saturation (SpO2) target results in optimal survival outcomes in those receiving mechanical ventilation. We therefore conducted a feasibility randomised controlled trial in the United Kingdom (UK) to assess whether it would be possible to host a larger national multi-centre trial to evaluate oxygenation targets in mechanically ventilated patients. METHODS: We set out to recruit 60 participants across two sites into a trial in which they were randomised to receive conservative oxygenation (SpO2 88-92%) or usual care (control - SpO2 ≥96%). The primary outcome was feasibility; factors related to safety and clinical outcomes were also assessed. RESULTS: A total of 34 patients were recruited into the study until it was stopped due to time constraints. A number of key barriers to success were identified during the course of the study. The conservative oxygenation intervention was feasible and appeared to be safe in this small patient cohort and it achieved wide separation of the median time-weighted average (IQR) SpO2 at 91% (90-92%) in conservative oxygenation group versus 97% (96-97%) in control group. CONCLUSION: Whilst conservative oxygenation was a feasible and safe intervention which achieved clear group separation in oxygenation levels, the model used in this trial will require alterations to improve future participant recruitment rates in the UK.

Relating oxygen partial pressure, saturation and content: the haemoglobin-oxygen dissociation curve.

The delivery of oxygen by arterial blood to the tissues of the body has a number of critical determinants including blood oxygen concentration (content), saturation (S O2 ) and partial pressure, haemoglobin concentration and cardiac output, including its distribution. The haemoglobin-oxygen dissociation curve, a graphical representation of the relationship between oxygen satur-ation and oxygen partial pressure helps us to understand some of the principles underpinning this process. Historically this curve was derived from very limited data based on blood samples from small numbers of healthy subjects which were manipulated in vitro and ultimately determined by equations such as those described by Severinghaus in 1979. In a study of 3524 clinical specimens, we found that this equation estimated the S O2 in blood from patients with normal pH and S O2 >70% with remarkable accuracy and, to our knowledge, this is the first large-scale validation of this equation using clinical samples. Oxygen saturation by pulse oximetry (S pO2 ) is nowadays the standard clinical method for assessing arterial oxygen saturation, providing a convenient, pain-free means of continuously assessing oxygenation, provided the interpreting clinician is aware of important limitations. The use of pulse oximetry reduces the need for arterial blood gas analysis (S aO2 ) as many patients who are not at risk of hypercapnic respiratory failure or metabolic acidosis and have acceptable S pO2 do not necessarily require blood gas analysis. While arterial sampling remains the gold-standard method of assessing ventilation and oxygenation, in those patients in whom blood gas analysis is indicated, arterialised capillary samples also have a valuable role in patient care. The clinical role of venous blood gases however remains less well defined.

Acute Aspergillus pneumonia associated with mouldy tree bark-chippings, complicated by anti-glomerular basement membrane disease causing permanent renal failure.

A non-immunocompromised man developed acute Aspergillus pneumonia after spreading mouldy tree bark mulch. Despite normal renal function at presentation, he developed rapidly progressive glomerulonephritis with acute kidney injury due to anti-glomerular basement membrane antibodies (anti-GBM) 4 weeks later. He remained dialysis dependent and died of sepsis 10 months later. We hypothesise that he contracted invasive pulmonary Aspergillosis from heavy exposure to fungal spores, leading to epitope exposure in the alveoli with subsequent development of GBM auto-antibodies.

Itraconazole associated quadriparesis and edema: a case report.

INTRODUCTION: Itraconazole is an anti-fungal agent widely used to treat various forms of mycosis. It is particularly useful in allergic bronchopulmonary aspergillosis and severe asthma with fungal sensitization. Side effects are uncommon and usually mild. Mild neuropathy is noted to occur very rarely. We present an unusual and, to the best of our knowledge, as yet unreported case of severe neuropathy and peripheral edema due to itraconazole in the absence of a concomitant risk factor. CASE PRESENTATION: A 72-year-old Caucasian man was started on itraconazole following diagnosis of severe asthma with fungal sensitization. One month later he presented with severe bilateral ankle edema with an elevated serum itraconazole level. The itraconazole dose was reduced but his ankle edema persisted and he developed weakness of all four limbs. Itraconazole was completely stopped leading to improvement in his leg edema but he became bed bound due to weakness. He gradually improved with supportive care and neurorehabilitation. On review at six months, our patient was able to mobilize with the aid of two elbow crutches and power had returned to 5/5 in distal extremities and 4+/5 in proximal extremities. The diagnosis was established based on the classical presentation of drug-induced neuropathy and negative investigatory findings for any alternative diagnoses. CONCLUSION: We report the case of a patient presenting with an unusual complication of severe neuropathy and peripheral edema due to itraconazole. Clinicians should be alert to this association when encountered with neuropathy and/or edema in an itraconazole therapy recipient.

Pre-medication for bronchoscopy: a randomised double blind trial comparing alfentanil with midazolam.

This study was designed to compare the effects of alfentanil and midazolam pre-medication on patient comfort during and after flexible bronchoscopy. A randomised, double-blind study was performed; 40 patients received alfentanil and 29 midazolam. Subjects completed questionnaires about discomfort and adverse effects immediately post-procedure and 24 h later. The bronchoscopist also completed a questionnaire. No difference in patient discomfort was found immediately post-procedure and no differences were found for amount of topical lignocaine used or minimum oxygen saturation. Operators reported no overall difference between the agents for ease of procedure but about 20% less cough was reported in the alfentanil group (P = 0.02). Patient discomfort scores in the 24h questionnaire were significantly lower in patients given midazolam (P = 0.01 for nasal discomfort, P = 0.003 for throat discomfort) but drowsiness was commoner in this group (P = 0.04). There was no significant difference in patients' reports of cough, nausea or vomiting or their willingness to have a repeat procedure. In conclusion, cough during bronchoscopy was slightly less marked with alfentanil than midazolam pre-medication but this made no difference to the ease of procedure or to overall patient discomfort. Patients given midazolam reported less discomfort when asked about the test 24 h later.