Application of Lung Ultrasound During the COVID-19 Pandemic: A Narrative Review

This review highlights the ultrasound findings reported from a number of studies and case reports and discusses the unifying findings from coronavirus disease (COVID-19) patients and from the avian (H7N9) and H1N1 influenza epidemics. We discuss the potential role for portable point-of-care ultrasound (PPOCUS) as a safe and effective bedside option in the initial evaluation, management, and monitoring of disease progression in patients with confirmed or suspected COVID-19 infection.

Ultrasound Teleguidance to Reduce Healthcare Worker Exposure to Coronavirus Disease 2019

The global spread of coronavirus disease 2019 has accelerated the adoption of technologies that facilitate patient care while reducing viral spread. We illustrate a proof of concept application of teleguidance to ultrasound-guided bedside procedures as an example of an innovative solution that has been used at our institution to maximize patient and provider safety.

In-hospital airway management of COVID-19 patients

Those involved in the airway management of COVID-19 patients are particularly at risk. Here, we describe a practical, stepwise protocol for safe in-hospital airway management in patients with suspected or confirmed COVID-19 infection.

The Presence of Scarring and Associated Morbidity in the Burn Model System National Database

INTRODUCTION

Postburn scarring is common, but the risk factors, natural history, and consequences of such scars are still poorly understood. This study aims to describe the frequency of scar-related morbidity for up to 2 years after injury and to analyze the impact of burn scars on long-term functional, psychosocial, and reintegration outcomes.

METHODS

Analysis was conducted on data collected between January 2006 and May 2014 from 960 patients (2440 anatomic burn sites) using the Burn Model System (BMS) database. Study population demographics were analyzed and odds ratios for the development of raised or thick scarring were determined. Regression analyses were used to evaluate the impact of hypertrophic scarring (HTS) on psychosocial outcomes, including the Community Integration Questionnaire, Satisfaction with Life Scale, Distress, and the Short Form 12. Symptoms associated with scarring were analyzed at discharge and 6, 12, and 24 months after burn using a set of questions on scarring developed by the BMS. Mixed-effect modeling was used to determine linear change over time and the significance of symptoms.

RESULTS

The study population was primarily white (65.0%) and male (71.8%), with a mean (SD) age of 44.0 (15.2) years and mean total body surface area burned of 19.6% (17.9%). The incidence of raised or thick scars increased from 65% to 80% (P < 0.0001) for the 2-year follow-up period. The presence of scarring was not associated with Community Integration Questionnaire, Satisfaction with Life Scale, or Short Form 12 scores. Most patients reported symptoms associated with scarring at 2 years after burn, including dry or fragile skin, scars that restrict range of motion at a joint, issues with hand function, and scar pain and itch.

CONCLUSIONS

In this large, longitudinal, multicenter cohort of burn survivors, nearly all patients noted the presence of scarring, and a majority noted additional symptoms and morbidity related to their scars even at 2 years after injury. This study demonstrates a need for the continued support of burn survivors to address scar-related morbidity. Furthermore, future studies examining the impact of novel treatments for scarring should use similar scar problem questionnaires and distress scores.

ST Elevations and Ventricular Tachycardia Secondary to Coronary Vasospasm upon Extubation

ST elevations (STE) in the perioperative setting can result from a number of different etiologies, the most common and feared being acute coronary syndrome (ACS). However, other causes should be considered, as treatment may differ depending on the diagnosis. Here, we describe a case of STE and ventricular tachycardia in a patient at high risk for ACS. The patient had a prior diagnosis of coronary vasospasm; however, given pre-existing risk factors, much consideration and deliberation occurred prior to electing conservative therapy. This report provides an overview of perioperative vasospasm and other causes of STE, which anesthesiologists should be aware of.

A lung rescue team improves survival in obesity with acute respiratory distress syndrome

BACKGROUND

Limited data exist regarding ventilation in patients with class III obesity [body mass index (BMI) > 40 kg/m2] and acute respiratory distress syndrome (ARDS). The aim of the present study was to determine whether an individualized titration of mechanical ventilation according to cardiopulmonary physiology reduces the mortality in patients with class III obesity and ARDS.

METHODS

In this retrospective study, we enrolled adults admitted to the ICU from 2012 to 2017 who had class III obesity and ARDS and received mechanical ventilation for > 48 h. Enrolled patients were divided in two cohorts: one cohort (2012-2014) had ventilator settings determined by the ARDSnet table for lower positive end-expiratory pressure/higher inspiratory fraction of oxygen (standard protocol-based cohort); the other cohort (2015-2017) had ventilator settings determined by an individualized protocol established by a lung rescue team (lung rescue team cohort). The lung rescue team used lung recruitment maneuvers, esophageal manometry, and hemodynamic monitoring.

RESULTS

The standard protocol-based cohort included 70 patients (BMI = 49 ± 9 kg/m2), and the lung rescue team cohort included 50 patients (BMI = 54 ± 13 kg/m2). Patients in the standard protocol-based cohort compared to lung rescue team cohort had almost double the risk of dying at 28 days [31% versus 16%, P = 0.012; hazard ratio (HR) 0.32; 95% confidence interval (CI95%) 0.13-0.78] and 3 months (41% versus 22%, P = 0.006; HR 0.35; CI95% 0.16-0.74), and this effect persisted at 6 months and 1 year (incidence of death unchanged 41% versus 22%, P = 0.006; HR 0.35; CI95% 0.16-0.74).

CONCLUSION

Individualized titration of mechanical ventilation by a lung rescue team was associated with decreased mortality compared to use of an ARDSnet table.

Examining the Learning Practice of Emergency Airway Management Within an Academic Medical Center: Implications for Training and Improving Outcomes

Emergency airway management (EAM) is a "high stakes" clinical practice, associated with a significant risk of procedure-related complications and patient mortality. Learning within the EAM team practice is complex and challenging for trainees. Increasing concern for patient safety and changes in the structure of medical education have resulted in educational challenges and opportunities for improvement within the EAM team practice. This paper is divided into 3 sections that describe the past, present, and future of the EAM team learning practice within a large academic institution. Section 1 provides a brief overview of the evolution of the existing practice of EAM. Key features, goals, and challenges of the practice are outlined and a recently performed needs analysis to identify areas for improvement is described. Section 2 examines the underlying assumptions regarding learning within the existing practice and explores how these assumptions fit into major theories of learning. Section 3 proposes an idealized learning practice for the EAM team which includes the assumptions regarding learners, design of the learning environment, use of technology to enhance learning, and the means of assessment and measuring success. It is hoped that through this systematic exploration of the EAM team practice, learning efficacy and efficiency will be improved and remain adaptable for challenges in the future.

Effect of nitric oxide on postoperative acute kidney injury in patients who underwent cardiopulmonary bypass: a systematic review and meta-analysis with trial sequential analysis

BACKGROUND

The effect of nitric oxide (NO) on renal function is controversial in critical illness. We performed a systematic meta-analysis and trial sequential analysis to determine the effect of NO gas on renal function and other clinical outcomes in patients requiring cardiopulmonary bypass (CPB). The primary outcome was the relative risk (RR) of acute kidney injury (AKI), irrespective of the AKI stage. The secondary outcome was the mean difference (MD) in the length of ICU and hospital stay, the RR of postoperative hemorrhage, and the MD in levels of methemoglobin. Trial sequential analysis (TSA) was performed for the primary outcome.

RESULTS

54 trials were assessed for eligibility and 5 studies (579 patients) were eligible for meta-analysis. NO was associated with reduced risk of AKI (RR 0.76, 95% confidential interval [CI], 0.62 to 0.93, I2 = 0%). In the subgroup analysis by NO initiation timing, NO did not decrease the risk of AKI when started at the end of CPB (RR 1.20, 95% CI 0.52-2.78, I2 = 0%). However, NO did significantly reduce the risk of AKI when started from the beginning of CPB (RR 0.71, 95% CI 0.54-0.94, I2 = 10%). We conducted TSA based on three trials (400 patients) using KDIGO criteria and with low risk of bias. TSA indicated a CI of 0.50-1.02 and an optimal information size of 589 patients, suggesting a lack of definitive conclusion. Furthermore, NO does not affect the length of ICU and hospital stay or the risk of postoperative hemorrhage. NO slightly increased the level of methemoglobin at the end of CPB (MD 0.52%, 95% CI 0.27-0.78%, I2 = 90%), but it was clinically negligible.

CONCLUSIONS

NO appeared to reduce the risk of postoperative AKI in patients undergoing CPB. Additional studies are required to ascertain the finding and further determine the dosage, timing and duration of NO administration.

Independent lung ventilation: Implementation strategies and review of literature

Independent lung ventilation, though infrequently used in the critical care setting, has been reported as a rescue strategy for patients in respiratory failure resulting from severe unilateral lung pathology. This involves isolating and ventilating the right and left lung differently, using separate ventilators. Here, we describe our experience with independent lung ventilation in a patient with unilateral diffuse alveolar hemorrhage, who presented with severe hypoxemic respiratory failure despite maximal ventilatory support. Conventional ventilation in this scenario leads to preferential distribution of tidal volume to the non-diseased lung causing over distension and inadvertent volume trauma. Since each lung has a different compliance and respiratory mechanics, instituting separate ventilation strategies to each lung could potentially minimize lung injury. Based on review of literature, we provide a detailed description of indications and procedures for establishing independent lung ventilation, and also provide an algorithm for management and weaning a patient from independent lung ventilation.

Protocol of a randomised controlled trial in cardiac surgical patients with endothelial dysfunction aimed to prevent postoperative acute kidney injury by administering nitric oxide gas

INTRODUCTION

Postoperative acute kidney injury (AKI) is a common complication in cardiac surgery. Levels of intravascular haemolysis are strongly associated with postoperative AKI and with prolonged (>90 min) use of cardiopulmonary bypass (CPB). Ferrous plasma haemoglobin released into the circulation acts as a scavenger of nitric oxide (NO) produced by endothelial cells. Consequently, the vascular bioavailability of NO is reduced, leading to vasoconstriction and impaired renal function. In patients with cardiovascular risk factors, the endothelium is dysfunctional and cannot replenish the NO deficit. A previous clinical study in young cardiac surgical patients with rheumatic fever, without evidence of endothelial dysfunction, showed that supplementation of NO gas decreases AKI by converting ferrous plasma haemoglobin to ferric methaemoglobin, thus preserving vascular NO. In this current trial, we hypothesised that 24 hours administration of NO gas will reduce AKI following CPB in patients with endothelial dysfunction.

METHODS

This is a single-centre, randomised (1:1) controlled, parallel-arm superiority trial that includes patients with endothelial dysfunction, stable kidney function and who are undergoing cardiac surgery procedures with an expected CPB duration >90 min. After randomisation, 80 parts per million (ppm) NO (intervention group) or 80 ppm nitrogen (N2, control group) are added to the gas mixture. Test gases (N2 or NO) are delivered during CPB and for 24 hours after surgery. The primary study outcome is the occurrence of AKI among study groups. Key secondary outcomes include AKI severity, occurrence of renal replacement therapy, major adverse kidney events at 6 weeks after surgery and mortality. We are recruiting 250 patients, allowing detection of a 35% AKI relative risk reduction, assuming a two-sided error of 0.05.

ETHICS AND DISSEMINATION

The Partners Human Research Committee approved this trial. Recruitment began in February 2017. Dissemination plans include presentations at scientific conferences, scientific publications and advertising flyers and posters at Massachusetts General Hospital.

TRIAL REGISTRATION NUMBER

NCT02836899.

Association of Overlapping Surgery With Perioperative Outcomes

IMPORTANCE

Overlapping surgery, in which more than 1 procedure performed by the same primary surgeon is scheduled so the start time of one procedure overlaps with the end time of another, is of concern because of potential adverse outcomes.

OBJECTIVE

To determine the association between overlapping surgery and mortality, complications, and length of surgery.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of 66 430 operations in patients aged 18 to 90 years undergoing total knee or hip arthroplasty; spine surgery; coronary artery bypass graft (CABG) surgery; and craniotomy at 8 centers between January 1, 2010, and May 31, 2018. Patients were followed up until discharge.

EXPOSURES

Overlapping surgery (≥2 operations performed by the same surgeon in which ≥1 hour of 1 case, or the entire case for those <1 hour, occurs when another procedure is being performed).

MAIN OUTCOMES AND MEASURES

Primary outcomes were in-hospital mortality or complications (major: thromboembolic event, pneumonia, sepsis, stroke, or myocardial infarction; minor: urinary tract or surgical site infection) and surgery duration.

RESULTS

The final sample consisted of 66 430 operations (mean patient age, 59 [SD, 15] years; 31 915 women [48%]), of which 8224 (12%) were overlapping. After adjusting for confounders, overlapping surgery was not associated with a significant difference in in-hospital mortality (1.9% overlapping vs 1.6% nonoverlapping; difference, 0.3% [95% CI, -0.2% to 0.7%]; P = .21) or risk of complications (12.8% overlapping vs 11.8% nonoverlapping; difference, 0.9% [95% CI, -0.1% to 1.9%]; P = .08). Overlapping surgery was associated with increased surgery length (204 vs 173 minutes; difference, 30 minutes [95% CI, 24 to 37 minutes]; P < .001). Overlapping surgery was significantly associated with increased mortality and increased complications among patients having a high preoperative predicted risk for mortality and complications, compared with low-risk patients (mortality: 5.8% vs 4.7%; difference, 1.2% [95% CI, 0.1% to 2.2%]; P = .03; complications: 29.2% vs 27.0%; difference, 2.3% [95% CI, 0.3% to 4.3%]; P = .03).

CONCLUSIONS AND RELEVANCE

Among adults undergoing common operations, overlapping surgery was not significantly associated with differences in in-hospital mortality or postoperative complication rates but was significantly associated with increased surgery length. Further research is needed to understand the association of overlapping surgery with these outcomes among specific patient subgroups.