Pneumomediastinum in COVID-19: a phenotype of severe COVID-19 pneumonitis? The results of the United Kingdom (POETIC) survey.

BACKGROUND: There is an emerging understanding that coronavirus disease 2019 (COVID-19) is associated with increased incidence of pneumomediastinum. We aimed to determine its incidence among patients hospitalised with COVID-19 in the United Kingdom and describe factors associated with outcome. METHODS: A structured survey of pneumomediastinum and its incidence was conducted from September 2020 to February 2021. United Kingdom-wide participation was solicited via respiratory research networks. Identified patients had SARS-CoV-2 infection and radiologically proven pneumomediastinum. The primary outcomes were to determine incidence of pneumomediastinum in COVID-19 and to investigate risk factors associated with patient mortality. RESULTS: 377 cases of pneumomediastinum in COVID-19 were identified from 58 484 inpatients with COVID-19 at 53 hospitals during the study period, giving an incidence of 0.64%. Overall 120-day mortality in COVID-19 pneumomediastinum was 195/377 (51.7%). Pneumomediastinum in COVID-19 was associated with high rates of mechanical ventilation. 172/377 patients (45.6%) were mechanically ventilated at the point of diagnosis. Mechanical ventilation was the most important predictor of mortality in COVID-19 pneumomediastinum at the time of diagnosis and thereafter (p<0.001) along with increasing age (p<0.01) and diabetes mellitus (p=0.08). Switching patients from continuous positive airways pressure support to oxygen or high flow nasal oxygen after the diagnosis of pneumomediastinum was not associated with difference in mortality. CONCLUSIONS: Pneumomediastinum appears to be a marker of severe COVID-19 pneumonitis. The majority of patients in whom pneumomediastinum was identified had not been mechanically ventilated at the point of diagnosis.

A randomised controlled trial of intrapleural balloon intercostal chest drains to prevent drain displacement.

BACKGROUND: Chest drain displacement is a common clinical problem that occurs in 9-42% of cases and results in treatment failure or additional pleural procedures conferring unnecessary risk. A novel chest drain with an integrated intrapleural balloon may reduce the risk of displacement. METHODS: A prospective randomised controlled trial comparing the balloon drain to standard care (12 F chest drain with no balloon) with the primary outcome of objectively defined unintentional or accidental chest drain displacement. RESULTS: 267 patients were randomised (primary outcome data available in 257, 96.2%). Displacement occurred less frequently using the balloon drain (displacement 5 of 128, 3.9%; standard care displacement 13 of 129, 10.1%) but this was not statistically significant (OR for drain displacement 0.36, 95% CI 0.13-1.0, Chi-squared 1 degree of freedom (df)=2.87, p=0.09). Adjusted analysis to account for minimisation factors and use of drain sutures demonstrated balloon drains were independently associated with reduced drain fall-out rate (adjusted OR 0.27, 95% CI 0.08-0.87, p=0.028). Adverse events were higher in the balloon arm than the standard care arm (balloon drain 59 of 131, 45.0%; standard care 18 of 132, 13.6%; Chi-squared 1 df=31.3, p<0.0001). CONCLUSION: Balloon drains reduce displacement compared with standard drains independent of the use of sutures but are associated with increased adverse events specifically during drain removal. The potential benefits of the novel drain should be weighed against the risks, but may be considered in practices where sutures are not routinely used.

Ambulatory management of secondary spontaneous pneumothorax: a randomised controlled trial.

Secondary spontaneous pneumothorax (SSP) is traditionally managed with an intercostal chest tube attached to an underwater seal. We investigated whether use of a one-way flutter valve shortened patients' length of stay (LoS).This open-label randomised controlled trial enrolled patients presenting with SSP and randomised to either a chest tube and underwater seal (standard care: SC) or ambulatory care (AC) with a flutter valve. The type of flutter valve used depended on whether at randomisation the patient already had a chest tube in place: in those without a chest tube a pleural vent (PV) was used; in those with a chest tube in situ, an Atrium Pneumostat (AP) valve was attached. The primary end-point was LoS.Between March 2017 and March 2020, 41 patients underwent randomisation: 20 to SC and 21 to AC (13=PV, 8=AP). There was no difference in LoS in the first 30 days following treatment intervention: AC (median=6 days, IQR 14.5) and SC (median=6 days, IQR 13.3). In patients treated with PV there was a high rate of early treatment failure (6/13; 46%), compared to patients receiving SC (3/20; 15%) (p=0.11) Patients treated with AP had no (0/8 0%) early treatment failures and a median LoS of 1.5 days (IQR 23.8).There was no difference in LoS between ambulatory and standard care. Pleural Vents had high rates of treatment failure and should not be used in SSP. Atrium Pneumostats are a safer alternative, with a trend towards lower LoS.

Ambulatory management of primary spontaneous pneumothorax: an open-label, randomised controlled trial.

BACKGROUND: Primary spontaneous pneumothorax occurs in otherwise healthy young patients. Optimal management is not defined and often results in prolonged hospitalisation. Data on efficacy of ambulatory options are poor. We aimed to describe the duration of hospitalisation and safety of ambulatory management compared with standard care. METHODS: In this open-label, randomised controlled trial, adults (aged 16-55 years) with symptomatic primary spontaneous pneumothorax were recruited from 24 UK hospitals during a period of 3 years. Patients were randomly assigned (1:1) to treatment with either an ambulatory device or standard guideline-based management (aspiration, standard chest tube insertion, or both). The primary outcome was total length of hospital stay including re-admission up to 30 days after randomisation. Patients with available data were included in the primary analysis and all assigned patients were included in the safety analysis. The trial was prospectively registered with the International Standard Randomised Clinical Trials Number, ISRCTN79151659. FINDINGS: Of 776 patients screened between July, 2015, and March, 2019, 236 (30%) were randomly assigned to ambulatory care (n=117) and standard care (n=119). At day 30, the median hospitalisation was significantly shorter in the 114 patients with available data who received ambulatory treatment (0 days [IQR 0-3]) than in the 113 with available data who received standard care (4 days [IQR 0-8]; p<0·0001; median difference 2 days [95% CI 1-3]). 110 (47%) of 236 patients had adverse events, including 64 (55%) of 117 patients in the ambulatory care arm and 46 (39%) of 119 in the standard care arm. All 14 serious adverse events occurred in patients who received ambulatory care, eight (57%) of which were related to the intervention, including an enlarging pneumothorax, asymptomatic pulmonary oedema, and the device malfunctioning, leaking, or dislodging. INTERPRETATION: Ambulatory management of primary spontaneous pneumothorax significantly reduced the duration of hospitalisation including re-admissions in the first 30 days, but at the expense of increased adverse events. This data suggests that primary spontaneous pneumothorax can be managed for outpatients, using ambulatory devices in those who require intervention. FUNDING: UK National Institute for Health Research.

Validating optimal function of the closed loop stimulation sensor with high right septal ventricular electrode placement in 'ablate and pace' patients.

PURPOSE: The study aim was to validate the closed loop stimulation (CLS) vs. accelerometer (ACC) rate-responsive sensors with electrodes placed in the right ventricular high septal (RVHS) or right ventricular apical (RVA) lead positions in patients following 'ablate and pace' therapy for persistent atrial fibrillation. METHODS: 'Ablate and pace' patients were randomised to either RVHS or RVA electrode placement with a dual sensor device. A double-blind crossover study comparing CLS vs. ACC rate-response pacing modes was undertaken. Subjects undertook cardiopulmonary testing with constant workload light exercise followed by a ramp protocol in addition to activity of daily living assessments. RESULTS: Twenty subjects (14 male; age, 74 +/- 8 years) were studied. Heart rate increase was greater from lying to sitting with ACC. With mental stress, heart rate increase was greater with CLS. Peak heart rates were similar for stair ascent and descent in ACC mode. With CLS mode, however, the peak heart rate was significantly lower for stair descent. There was no difference between modes in mean response time, oxygen deficit, peak VO(2), VO(2) at anaerobic threshold, peak heart rate, total exercise time and total workload. CLS function was equally optimal at both electrode sites. CONCLUSIONS: CLS rate adaptive pacing is appropriate for 'ablate and pace' patients, and this sensor functions equally well using RVA or RVHS lead positions.

Electrophysiological characteristics associated with symptoms in pacemaker patients with paroxysmal atrial fibrillation.

PURPOSE: The purpose of this study is to identify the electrophysiological factors affecting symptoms in paroxysmal atrial fibrillation (PAF) using patients with paroxysmal atrial fibrillation and pacemakers with advanced atrial fibrillation (AF) diagnostics. METHODS: Seventy-nine patients (age 71.0 +/- 8.2, 54.4% male) with symptomatic PAF and AF burden of 1% to 50% with DDDRP pacemakers implanted were assessed for 6 months. Patients recorded symptom onset and duration and these were correlated with device-derived electrophysiological data. RESULTS: Of 2,638 AF episodes, 333 were symptomatic and 2,305 asymptomatic, with 194 non-atrial tachyarrhythmia symptomatic episodes giving a sensitivity of 12.6% and a positive predictive value of 63.2% for specific AF symptoms. Symptomatic AF episodes were 3.8 times more common diurnally than nocturnally (p < 0.001). Diurnally, symptomatic AF was significantly associated with a shorter AF cycle length (CL; p = 0.04), faster ventricular rate (p = 0.004), shorter PR interval (p < 0.001), faster preceding heart rate (p = 0.001) and increased early recurrence of AF (p < 0.04). Nocturnally, a significantly longer AF CL (p = 0.04) and PR interval (p < 0.001) prior to AF onset predicted symptomatic AF. CONCLUSIONS: Symptoms in PAF are predicted by changes in AF episode duration, ventricular rate during AF, preceding sinus heart rate, AV nodal conduction and AF cycle length but not ventricular irregularity. Excess diurnal sympathetic tone and excess nocturnal vagal tone predispose to symptomatic PAF. These findings may have relevance for therapies for symptom control of PAF.