Conventional oxygen therapy versus CPAP as a ceiling of care in ward-based patients with COVID-19: a multi-centre cohort evaluation

BACKGROUND

Continuous positive airway pressure (CPAP) therapy is commonly used for respiratory failure due to severe COVID-19 pneumonitis, including in patients deemed not likely to benefit from invasive mechanical ventilation (nIMV). Little evidence exists demonstrating superiority over conventional oxygen therapy, whilst ward-level delivery of CPAP presents practical challenges. We sought to compare clinical outcomes of oxygen therapy versus CPAP therapy in patients with COVID-19 who were nIMV.

METHODS

This retrospective multi-centre cohort evaluation included patients diagnosed with COVID-19 who were nIMV, had a treatment escalation plan of ward-level care and clinical frailty scale ≤ 6. Recruitment occurred during the first two waves of the UK COVID-19 pandemic in 2020; from 1^st March to May 31^st, and from 1^st September to 31^st December. Patients given CPAP were compared to patients receiving oxygen therapy that required FiO₂ ≥0_.4 for more than 12 hours at hospitals not providing ward-level CPAP. Logistic regression modelling was performed to compare 30-day mortality between treatment groups, accounting for important confounders and within-hospital clustering.

FINDINGS

Seven hospitals provided data for 479 patients during the UK COVID-19 pandemic in 2020. Overall 30-day mortality was 75.6% in the oxygen group (186/246 patients) and 77.7% in the CPAP group (181/233 patients). A lack of evidence for a treatment effect persisted in the adjusted model (adjusted odds ratio 0.84 95% CI 0.57-1.23, p=0.37). 49.8% of patients receiving CPAP-therapy (118/237) chose to discontinue it.

INTERPRETATION

No survival difference was found between using oxygen alone or CPAP to treat patients with severe COVID-19 who were nIMV. A high patient-initiated discontinuation rate for CPAP suggests a significant treatment burden. Further reflection is warranted on the current treatment guidance and widespread application of CPAP in this setting.

FUNDING

L Pearmain is supported by the MRC (MR/R00191X/1). TW Felton is supported by the NIHR Manchester Biomedical Research Centre.

Developing multidisciplinary profiles in a day hospital

The Ferguson Day Hospital provides a patient-centred, multidisciplinary service for patient assessment and rehabilitation. The authors describe the development of a patient profile that has centralised documentation and reflects the multidisciplinary nature of the services provided.

Value of standardized gestational age charts for fetuses of first-generation Oriental immigrants to Canada

OBJECTIVE

to ascertain if standard gestational age charts can be used to accurately predict the gestational age of fetuses of first-generation Oriental immigrants to Canada.

PATIENTS AND METHODS

Over a 3-year period, all patients presenting for obstetric ultrasound examinations were invited to participate in the study. The authors recorded biparietal diameter, head circumference, femur length and abdominal circumference for 139 fetuses in the second and third trimesters. A study performed in the first trimester was used as the baseline for gestational age. The data for 126 of the fetuses were complete, and these data were used for the analysis.

RESULTS

For 77 of the fetuses, both parents were Oriental, and for 49, one or both parents were not Oriental; the latter constituted the control group. A total of 1008 individual measurements were obtained, and of these, all but 14 fell within two standard deviations of the norm, according to standard gestational age charts. Of the abnormal measurements, seven were obtained from five fetuses with Oriental parents, and seven were obtained from six fetuses in the control group. The difference between the two groups in the proportion of measurements falling either above or below two standard deviations from the norm was not statistically significant (Fisher's exact test, p = 0.41694).

CONCLUSION

The authors conclude that standard gestational age charts can be used to determine gestational age in first-generation Oriental immigrants to Canada.

Role of intraoperative ultrasonography in hepatic surgery: a preliminary report

Twenty-four patients who underwent ultrasonography during hepatic surgery in the 22 months from October 1989 to July 1991 were studied prospectively to determine the value, if any, of intraoperative ultrasonography. For 6 (25%) of the 24 patients the operative plan was altered because of the ultrasonographic findings. In one of them resection was extended from a left lateral segmentectomy or sectorectomy to a left hemihepatectomy. In the other five patients the planned liver procedure was abandoned. Two of these five patients were cirrhotic--in one of them an additional metastasis was seen, and in the other there was tumour invasion of the portal vein. Of the three noncirrhotic patients, one had tumour invasion of the right hepatic vein, and the other two patients had additional metastases in the caudate lobe (Couinaud segment 1). Ultrasonography was found to be useful in 25% of patients who underwent this investigation during hepatic surgery--it avoided liver resections that would have failed because of advanced malignant disease.

Pneumothorax: radiologic treatment with small catheters

In many institutions, the standard treatment of symptomatic and large pneumothoraxes has been with surgically placed large-bore (22-32-F) chest tubes. During the past 3-4 years, the authors used small catheters (7, 8.2, and 9.4 F) to decompress 30 pneumothoraxes (15 under tension) resulting from percutaneous lung biopsy. The catheters were inserted under computed tomographic or fluoroscopic guidance for the treatment of large (greater than 35%) or symptomatic pneumothoraxes. Twenty-eight of 30 patients were treated successfully with the small catheters alone; two patients underwent surgical placement of 32-F tubes (4 and 12 hours later) because of incomplete resolution of the pneumothoraxes. This series demonstrates that small-caliber catheters effectively decompress pneumothoraxes and that they can be inserted expeditiously by radiologists in the radiology department.

Abscesses in Crohn disease: percutaneous drainage

Fifteen patients with Crohn disease underwent percutaneous catheter drainage of related abdominal abscesses. The abscesses were located in the right lower quadrant (five patients); in the quadratus lumborum and/or iliopsoas muscles (four patients); in the left paracolic gutter (two patients); and in the right gluteal muscles, the liver, the left subphrenic space, and the pelvis (one patient each). All abscesses were evacuated successfully (n = 15 of 15), and no patient required surgery for abscess drainage. Existing fistulas closed in four of seven patients; the other three patients underwent surgery for excision of diseased bowel and enteric fistulas. No patient developed an enterocutaneous fistula as a result of catheter drainage. Percutaneous abscess drainage is effective for abscesses related to Crohn disease and should be regarded as the procedure of choice. An operation for the abscess can be avoided, and early results suggest that bowel surgery may be obviated in selected patients.

Percutaneous diagnostic and therapeutic interventional radiologic procedures in children: experience in 100 patients

Diagnostic and therapeutic interventional radiologic procedures that provide many treatment options in adults are gaining acceptance in pediatric medicine. Diagnostic (69 patients) and therapeutic (31 patients) interventional experiences in 100 children are summarized, and the procedures of choice for various clinical problems are outlined. Procedures include percutaneous biopsy for benign and malignant diseases, transhepatic cholangiography and biliary drainage, genitourinary procedures (nephrostomy, stent placement, balloon dilation), aspiration of fluid for laboratory analysis, therapeutic drainage of abscesses and noninfected fluid collections, and percutaneous gastrostomy and gastroenterostomy. Diagnoses were accurate in 96% of cases, and therapeutic procedures were successful in 84% of patients, usually obviating operation. Complications occurred in six patients (6%); the most severe was hemoptysis causing respiratory distress. There was no procedure-related mortality. Interventional procedures have wide applications in pediatric patients.

Lymphoceles: imaging characteristics and percutaneous management

Twenty-five patients who had lymphoceles underwent sectional imaging and interventional radiologic procedures. Viewed using sonography, lymphoceles were hypoechoic to anechoic, occasionally with internal septa and debris. Low numbers (occasionally negative values) were observed using computed tomography (CT); these numbers strongly suggest the diagnosis of lymphocele. Calcification was observed on CT images of one patient. Diagnostic aspiration revealed tan to yellow fluid containing many lymphocytes; pathognomonic fat globules were observed in four cases. Malignant cells were found in two collections, an unusual occurrence. Therapeutic needle aspiration and short-term catheter drainage were usually unsuccessful (only one of five patients [20%] was cured). Long-term (1-5-week) catheter drainage cured 11 of 14 patients (78.6%). Sclerosing agents may have been beneficial for lymphocele obliteration in three of four patients. For most patients, lymphoceles may be diagnosed and treated successfully using radiologic means.

Unsuspected pheochromocytoma: risk of blood-pressure alterations during percutaneous adrenal biopsy

Four unsuspected pheochromocytomas were discovered during percutaneous fine-needle biopsy of the adrenal gland under ultrasound (n = 1) and computed tomographic (n = 3) guidance. One patient suffered an acute episode of alternating hypertension and hypotension during the procedure. A second patient had no alterations in vital signs during the procedure but had a severe hypertensive crisis during induction of anesthesia at surgery. Neither biopsy nor surgery affected the vital signs in the other two patients. During biopsy study of adrenal lesions, the possibility of unsuspected pheochromocytoma should be considered, and the interventional radiologist must be familiar with the emergency treatment of hypotensive or hypertensive crises that may occur.

Percutaneous cecostomy for decompression of the massively distended cecum

Massive dilatation of the cecum developed in an elderly man following admission for an acute episode of upper gastrointestinal hemorrhage complicated by myocardial infarction, ventricular fibrillation, and pulmonary edema. A diagnosis of pseudo-obstruction was made. After an unsuccessful attempt at colonoscopy, percutaneous cecostomy was performed under computed tomographic guidance, using trocar technique. The cecal distention resolved and did not recur. Percutaneous cecostomy is an alternative to colonoscopy and to surgical cecostomy in the treatment of massive cecal distention.

The air-filled left hepatic duct: the saber sign as an aid to the radiographic diagnosis of pneumobilia

In the supine patient, gas rises to the left hepatic duct. Radiographically, this can be recognized as a saber-shaped lucency to the right of the spine. In a retrospective analysis and review of the radiographs of 40 patients shown to have gas in the biliary tree by ultrasound (US), computed tomography (CT), or radiography, the diagnosis could be made in 37 patients. In 18 of these 37 cases pneumobilia could be identified by the saber-shaped distribution of gas. Knowledge of the medial distribution of biliary gas in the supine patient and appreciation of the saber sign can increase the sensitivity of the radiographic detection of pneumobilia.