Chang M. Right Ventricular Strain Is Common in Intubated COVID-19 Patients and Does Not Reflect Severity of Respiratory Illness

BACKGROUND

Right ventricular (RV) dysfunction is common and associated with worse outcomes in patients with coronavirus disease 2019 (COVID-19). In non-COVID-19 acute respiratory distress syndrome, RV dysfunction develops due to pulmonary hypoxic vasoconstriction, inflammation, and alveolar overdistension or atelectasis. Although similar pathogenic mechanisms may induce RV dysfunction in COVID-19, other COVID-19-specific pathology, such as pulmonary endothelialitis, thrombosis, or myocarditis, may also affect RV function. We quantified RV dysfunction by echocardiographic strain analysis and investigated its correlation with disease severity, ventilatory parameters, biomarkers, and imaging findings in critically ill COVID-19 patients.

METHODS

We determined RV free wall longitudinal strain (FWLS) in 32 patients receiving mechanical ventilation for COVID-19-associated respiratory failure. Demographics, comorbid conditions, ventilatory parameters, medications, and laboratory findings were extracted from the medical record. Chest imaging was assessed to determine the severity of lung disease and the presence of pulmonary embolism.

RESULTS

Abnormal FWLS was present in 66% of mechanically ventilated COVID-19 patients and was associated with higher lung compliance (39.6 vs 29.4 mL/cmH2O, P = 0.016), lower airway plateau pressures (21 vs 24 cmH2O, P = 0.043), lower tidal volume ventilation (5.74 vs 6.17 cc/kg, P = 0.031), and reduced left ventricular function. FWLS correlated negatively with age (r = -0.414, P = 0.018) and with serum troponin (r = 0.402, P = 0.034). Patients with abnormal RV strain did not exhibit decreased oxygenation or increased disease severity based on inflammatory markers, vasopressor requirements, or chest imaging findings.

CONCLUSIONS

RV dysfunction is common among critically ill COVID-19 patients and is not related to abnormal lung mechanics or ventilatory pressures. Instead, patients with abnormal FWLS had more favorable lung compliance. RV dysfunction may be secondary to diffuse intravascular micro- and macro-thrombosis or direct myocardial damage.

TRIAL REGISTRATION

National Institutes of Health #NCT04306393. Registered 10 March 2020, https://clinicaltrials.gov/ct2/show/NCT04306393.

Free Hemoglobin Ratio as a Novel Biomarker of Acute Kidney Injury After On-Pump Cardiac Surgery: Secondary Analysis of a Randomized Controlled Trial

BACKGROUND

Cardiac surgery with cardiopulmonary bypass (CPB) is associated with a high risk of postoperative acute kidney injury (AKI). Due to limitations of current diagnostic strategies, we sought to determine whether free hemoglobin (fHb) ratio (ie, levels of fHb at the end of CPB divided by baseline fHb) could predict AKI after on-pump cardiac surgery.

METHODS

This is a secondary analysis of a randomized controlled trial comparing the effect of nitric oxide (intervention) versus nitrogen (control) on AKI after cardiac surgery (NCT01802619). A total of 110 adult patients in the control arm were included. First, we determined whether fHb ratio was associated with AKI via multivariable analysis. Second, we verified whether fHb ratio could predict AKI and incorporation of fHb ratio could improve predictive performance at an early stage, compared with prediction using urinary biomarkers alone. We conducted restricted cubic spline in logistic regression for model development. We determined the predictive performance, including area under the receiver-operating-characteristics curve (AUC) and calibration (calibration plot and accuracy, ie, number of correct predictions divided by total number of predictions). We also used AUC test, likelihood ratio test, and net reclassification index (NRI) to compare the predictive performance between competing models (ie, fHb ratio versus neutrophil gelatinase-associated lipocalin [NGAL], N-acetyl-β-d-glucosaminidase [NAG], and kidney injury molecule-1 [KIM-1], respectively, and incorporation of fHb ratio with NGAL, NAG, and KIM-1 versus urinary biomarkers alone), if applicable.

RESULTS

Data stratified by median fHb ratio showed that subjects with an fHb ratio >2.23 presented higher incidence of AKI (80.0% vs 49.1%; P = .001), more need of renal replacement therapy (10.9% vs 0%; P = .036), and higher in-hospital mortality (10.9% vs 0%; P = .036) than subjects with an fHb ratio ≤2.23. fHb ratio was associated with AKI after adjustment for preestablished factors. fHb ratio outperformed urinary biomarkers with the highest AUC of 0.704 (95% confidence interval [CI], 0.592-0.804) and accuracy of 0.714 (95% CI, 0.579-0.804). Incorporation of fHb ratio achieved better discrimination (AUC test, P = .012), calibration (likelihood ratio test, P < .001; accuracy, 0.740 [95% CI, 0.617-0.832] vs 0.632 [95% CI, 0.477-0.748]), and significant prediction increment (NRI, 0.638; 95% CI, 0.269-1.008; P < .001) at an early stage, compared with prediction using urinary biomarkers alone.

CONCLUSIONS

Results from this exploratory, hypothesis-generating retrospective, observational study shows that fHb ratio at the end of CPB might be used as a novel, widely applicable biomarker for AKI. The use of fHb ratio might help for an early detection of AKI, compared with prediction based only on urinary biomarkers.

Efficiency of Prolonged Prone Positioning for Mechanically Ventilated Patients Infected with COVID-19

Hypoxemia of the acute respiratory distress syndrome can be reduced by turning patients prone. Prone positioning (PP) is labor intensive, risks unplanned tracheal extubation, and can result in facial tissue injury. We retrospectively examined prolonged, repeated, and early versus later PP for 20 patients with COVID-19 respiratory failure. Blood gases and ventilator settings were collected before PP, at 1, 7, 12, 24, 32, and 39 h after PP, and 7 h after completion of PP. Analysis of variance was used for comparisons with baseline values at supine positions before turning prone. PP for >39 h maintained PaO₂/FiO₂ (P/F) ratios when turned supine; the P/F decrease at 7 h was not significant from the initial values when turned supine. Patients turned prone a second time, when again turned supine at 7 h, had significant decreased P/F. When PP started for an initial P/F ≤ 150 versus P/F > 150, the P/F increased throughout the PP and upon return to supine. Our results show that a single turn prone for >39 h is efficacious and saves the burden of multiple prone turns, and there is no significant advantage to initiating PP when P/F > 150 compared to P/F ≤ 150.

Individualized Multimodal Physiologic Approach to Mechanical Ventilation in Patients With Obesity and Severe Acute Respiratory Distress Syndrome Reduced Venovenous Extracorporeal Membrane Oxygenation Utilization

Supplemental Digital Content is available in the text.

OBJECTIVE:

To investigate whether individualized optimization of mechanical ventilation through the implementation of a lung rescue team could reduce the need for venovenous extracorporeal membrane oxygenation in patients with obesity and acute respiratory distress syndrome and decrease ICU and hospital length of stay and mortality.

DESIGN:

Single-center, retrospective study at the Massachusetts General Hospital from June 2015 to June 2019.

PATIENTS:

All patients with obesity and acute respiratory distress syndrome who were referred for venovenous extracorporeal membrane oxygenation evaluation due to hypoxemic respiratory failure.

INTERVENTION:

Evaluation and individualized optimization of mechanical ventilation by the lung rescue team before the decision to proceed with venovenous extracorporeal membrane oxygenation. The control group was those patients managed according to hospital standard of care without lung rescue team evaluation.

MEASUREMENT AND MAIN RESULTS:

All 20 patients (100%) allocated in the control group received venovenous extracorporeal membrane oxygenation, whereas 10 of 13 patients (77%) evaluated by the lung rescue team did not receive venovenous extracorporeal membrane oxygenation. Patients who underwent lung rescue team evaluation had a shorter duration of mechanical ventilation (p = 0.03) and shorter ICU length of stay (p = 0.03). There were no differences between groups in in-hospital, 30-day, or 1–year mortality.

CONCLUSIONS:

In this hypothesis-generating study, individualized optimization of mechanical ventilation of patients with acute respiratory distress syndrome and obesity by a lung rescue team was associated with a decrease in the utilization of venovenous extracorporeal membrane oxygenation, duration of mechanical ventilation, and ICU length of stay. Mortality was not modified by the lung rescue team intervention.

An examination of gastrointestinal absorption using the acetaminophen absorption test in critically ill patients with COVID-19: A retrospective cohort study

OBJECTIVE

Gastrointestinal (GI) dysfunction is prevalent in critically ill patients with coronavirus disease 2019 (COVID-19). The acetaminophen absorption test (AAT) has been previously described as a direct method for assessment of GI function. Our study determines whether the AAT can be used to assess GI function in critically ill COVID-19 patients, compared with traditional measures of GI function.

DESIGN

Retrospective observational study of critically ill patients with COVID-19.

SETTING

Three intensive care units at a tertiary care academic medical center.

PATIENTS

Twenty critically ill patients with COVID-19.

INTERVENTIONS

The results of AAT and traditional measures for assessing GI function were collected and compared.

MEASUREMENTS AND MAIN RESULTS

Among the study cohort, 55% (11 of 20) of patients had evidence of malabsorption by AAT. Interestingly, all patients with evidence of malabsorption by AAT had clinical evidence of bowel function, as indicated by stool output and low gastric residuals during the prior 24 h. When comparing patients with a detectable acetaminophen level (positive AAT) with those who had undetectable acetaminophen levels (negative AAT), radiologic evidence of ileus was less frequent (20 vs 88%; P = .03), tolerated tube-feed rates were higher (40 vs 10 ml/h; P =.01), and there was a trend toward lower gastric residual volumes (45 vs 830 ml; P =.11).

CONCLUSION

Malabsorption can occur in critically ill patients with COVID-19 despite commonly used clinical indicators of tube-feeding tolerance. The AAT provides a simple, rapid, and cost-effective mechanism by which enteral function can be efficiently assessed in COVID-19 patients.

An examination of sedation requirements and practices for mechanically ventilated critically ill patients with COVID-19

PURPOSE

Preliminary reports suggest that critically ill patients with coronavirus disease 2019 (COVID-19) infection requiring mechanical ventilation may have markedly increased sedation needs compared with non-mechanically ventilated patients. We conducted a study to examine sedative use for this patient population within multiple intensive care units (ICUs) of a large academic medical center.

METHODS

A retrospective, single-center cohort study of sedation practices for critically ill patients with COVID-19 during the first 10 days of mechanical ventilation was conducted in 8 ICUs at Massachusetts General Hospital, Boston, MA. The study population was a sequential cohort of 86 critically ill, mechanically ventilated patients with COVID-19. Data characterizing the sedative medications, doses, drug combinations, and duration of administration were collected daily and compared to published recommendations for sedation of critically ill patients without COVID-19. The associations between drug doses, number of drugs administered, baseline patient characteristics, and inflammatory markers were investigated.

RESULTS

Among the study cohort, propofol and hydromorphone were the most common initial drug combination, with these medications being used on a given day in up to 100% and 88% of patients, respectively. The doses of sedative and analgesic infusions increased for patients over the first 10 days, reaching or exceeding the upper limits of published dosage guidelines for propofol (48% of patients), dexmedetomidine (29%), midazolam (7.7%), ketamine (32%), and hydromorphone (38%). The number of sedative and analgesic agents simultaneously administered increased over time for each patient, with more than 50% of patients requiring 3 or more agents by day 2. Compared with patients requiring 3 or fewer agents, as a group patients requiring more than 3 agents were of younger age, had an increased body mass index, increased serum ferritin and lactate dehydrogenase concentrations, had a lower PaO2:FIO2 (ratio of arterial partial pressure of oxygen to fraction of inspired oxygen), and were more likely to receive neuromuscular blockade.

CONCLUSION

Our study confirmed the clinical impression of elevated sedative use in critically ill, mechanically ventilated patients with COVID-19 relative to guideline-recommended sedation practices in other critically ill populations.

Multisystem effects of COVID-19: a concise review for practitioners

While COVID-19 has primarily been characterized by the respiratory impact of viral pneumonia, it affects every organ system and carries a high consequent risk of death in critically ill patients. Higher sequential organ failure assessment (SOFA) scores have been associated with increased mortality in patients critically ill patients with COVID-19. It is important that clinicians managing critically ill COVID-19 patients be aware of the multisystem impact of the disease so that care can be focused on the prevention of end-organ injuries to potentially improve clinical outcomes. We review the multisystem complications of COVID-19 and associated treatment strategies to improve the care of critically ill COVID-19 patients.

Ensuring competency in focused cardiac ultrasound: a systematic review of training programs

BACKGROUND

Focused cardiac ultrasound (FoCUS) is a valuable skill for rapid assessment of cardiac function and volume status. Despite recent widespread adoption among physicians, there is limited data on the optimal training methods for teaching FoCUS and metrics for determining competency. We conducted a systematic review to gain insight on the optimal training strategies, including type and duration, that would allow physicians to achieve basic competency in FoCUS.

METHODS

Embase, PubMed, and Cochrane Library databases were searched from inception to June 2020. Included studies described standardized training programs for at least 5 medical students or physicians on adult FoCUS, followed by an assessment of competency relative to an expert. Data were extracted, and bias was assessed for each study.

RESULTS

Data were extracted from 23 studies on 292 learners. Existing FoCUS training programs remain varied in duration and type of training. Learners achieved near perfect agreement (κ > 0.8) with expert echocardiographers on detecting left ventricular systolic dysfunction and pericardial effusion with 6 h each of didactics and hands-on training. Substantial agreement (κ > 0.6) on could be achieved in half this time.

CONCLUSION

A short training program will allow most learners to achieve competency in detecting left ventricular systolic dysfunction and pericardial effusion by FoCUS. Additional training is necessary to ensure skill retention, improve efficiency in image acquisition, and detect other pathologies.

Sodium-glucose cotransporter-2 (SGLT2) inhibitor-induced euglycemic diabetic ketoacidosis complicating the perioperative management of a patient with type 2 diabetes mellitus (T2DM) and Fournier's gangrene: A case report

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This case highlights two serious side effects of empagliflozin occurring concurrently. Those being diabetic ketoacidosis and Fournier’s gangrene.

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Diabetic ketoacidosis is an important cause of perioperative high anion gap metabolic acidosis in the context of SGLT2 inhibitors and needs to be carefully managed.

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SGLT2 inhibitors should be held up to 48 h prior to surgery to minimize the risk of diabetic ketoacidosis perioperatively.

Introduction

Sodium glucose cotransporter-2 inhibitors (SGLT2) are an increasingly administered class of medication used to lower blood glucose levels in patients with type 2 diabetes mellitus. Diabetic ketoacidosis (DKA) and Fournier’s gangrene are rare, but potentially catastrophic side effects of SGLT2 inhibitors. This manuscript reports a case of both DKA and Fournier’s gangrene in the context of SGLT2 inhibitor use.

Presentation of case

A 51-year-old morbidly obese man with hypertension and poorly controlled Type 2 Diabetes Mellitus presented to the emergency department with a clinical presentation consistent with Fournier’s gangrene. He was promptly taken to the operating room by the urology team where he had extensive debridement of the perineum and abdomen. Intra-operatively he was found to have DKA, which was managed appropriately. The acidosis and Fournier’s gangrene were deemed a likely side effect of SGLT2 inhibitor use. After a thirty-day hospital admission, the patient was discharged to a rehabilitation facility where he is progressing well. His SGLT2 inhibitor was discontinued upon admission to hospital.

Discussion

Perioperative providers should have a high index of suspicion for diabetic ketoacidosis (DKA) and Fournier’s gangrene in patients prescribed SGLT2 inhibitors. Prompt treatment of DKA through correction of underlying triggers, aggressive fluid resuscitation, insulin to close the anion gap, and appropriate potassium repletion is vital to optimize patient outcomes.

Conclusion

The use of SGLT2 inhibitors among surgical populations is increasing. This case highlights the importance of being aware of the mechanism and side effects of SGLT2 inhibitors, and the management of DKA.

Use of Handheld Point-of-Care Ultrasound in Emergency Airway Management

Emergency airway management (EAM) is associated with a high rate of complications, morbidity, and mortality. Handheld point-of-care ultrasound shows promise as an emerging technology to facilitate rapid screening for difficult laryngoscopy, identify the cricothyroid membrane for potential cricothyroidotomy, and assess for increased aspiration risk, as well as provide confirmation of proper endotracheal tube positioning. This review summarizes the available evidence for the use of point-of-care ultrasound in EAM, provides an algorithm to facilitate its incorporation into existing EAM practice to improve patient safety, and serves as a framework for future validation studies.

Comparison of published guidelines for management of coagulopathy and thrombosis in critically ill patients with COVID 19: implications for clinical practice and future investigations

Critically ill patients with COVID-19 are at increased risk for thrombotic complications which has led to an intense debate surrounding their anticoagulation management. In the absence of data from randomized controlled clinical trials, a number of consensus guidelines and recommendations have been published to facilitate clinical decision-making on this issue. However, substantive differences exist between these guidelines which can be difficult for clinicians. This review briefly summarizes the major societal guidelines and compares their similarities and differences. A common theme in all of the recommendations is to take an individualized approach to patient management and a call for prospective randomized clinical trials to address important anticoagulation issues in this population.

High Pleural Pressure Prevents Alveolar Overdistension and Hemodynamic Collapse in ARDS with Class III Obesity

Rationale: Obesity is characterized by elevated pleural pressure (Ppl) and worsening atelectasis during mechanical ventilation in patients with acute respiratory distress syndrome (ARDS).

Objectives: To determine the effects of a lung recruitment maneuver (LRM) in the presence of elevated Ppl on hemodynamics, left and right ventricular pressure, and pulmonary vascular resistance. We hypothesized that elevated Ppl protects the cardiovascular system against high airway pressure and prevents lung overdistension.

Methods: First, an interventional crossover trial in adult subjects with ARDS and a body mass index ≥ 35 kg/m² (n = 21) was performed to explore the hemodynamic consequences of the LRM. Second, cardiovascular function was studied during low and high positive end-expiratory pressure (PEEP) in a model of swine with ARDS and high Ppl (n = 9) versus healthy swine with normal Ppl (n = 6).

Measurements and Main Results: Subjects with ARDS and obesity (body mass index = 57 ± 12 kg/m²) after LRM required an increase in PEEP of 8 (95% confidence interval [95% CI], 7–10) cm H₂O above traditional ARDS Network settings to improve lung function, oxygenation and V./Q. matching, without impairment of hemodynamics or right heart function. ARDS swine with high Ppl demonstrated unchanged transmural left ventricular pressure and systemic blood pressure after the LRM protocol. Pulmonary arterial hypertension decreased (8 [95% CI, 13–4] mm Hg), as did vascular resistance (1.5 [95% CI, 2.2–0.9] Wood units) and transmural right ventricular pressure (10 [95% CI, 15–6] mm Hg) during exhalation. LRM and PEEP decreased pulmonary vascular resistance and normalized the V./Q. ratio.

Conclusions: High airway pressure is required to recruit lung atelectasis in patients with ARDS and class III obesity but causes minimal overdistension. In addition, patients with ARDS and class III obesity hemodynamically tolerate LRM with high airway pressure.

Clinical trial registered with www.clinicaltrials.gov (NCT 02503241).

A low dose heparinized saline protocol is associated with improved duration of arterial line patency in critically ill COVID-19 patients

Purpose

Critically ill patients with Coronavirus Disease 2019 (COVID-19) have high rates of line thrombosis. Our objective was to examine the safety and efficacy of a low dose heparinized saline (LDHS) arterial line (a-line) patency protocol in this population.

Materials and Methods

In this observational cohort study, patients ≥18 years with COVID-19 admitted to an ICU at one institution from March 20–May 25, 2020 were divided into two cohorts. Pre-LDHS patients had an episode of a-line thrombosis between March 20–April 19. Post-LDHS patients had an episode of a-line thrombosis between April 20–May 25 and received an LDHS solution (10 units/h) through their a-line pressure bag.

Results

Forty-one patients (pre-LDHS) and 30 patients (post-LDHS) were identified. Baseline characteristics were similar between groups, including age (61 versus 54 years; p = 0.24), median Sequential Organ Failure Assessment score (6 versus 7; p = 0.67) and systemic anticoagulation (47% versus 32%; p = 0.32). Median duration of a-line patency was significantly longer in post-LDHS versus pre-LDHS patients (8.5 versus 2.9 days; p < 0.001). The incidence of bleeding complications was similar between cohorts (13% vs. 10%; p = 0.71).

Conclusions

A LDHS protocol was associated with a clinically significant improvement in a-line patency duration in COVID-19 patients, without increased bleeding risk.

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Critically ill COVID-19 patients have frequent arterial line (a-line) thrombosis.

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A low dose heparinized saline (LDHS) a-line patency protocol was examined.

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Two a-line thrombosis cohorts were identified: “post-LDHS” and “pre-LDHS”.

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A-line patency was longer in post- vs. pre-LDHS patients (8.5 vs. 2.9 d; p < 0.001).

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Bleeding complications were similar between groups (13% vs. 10%, p = 0.7).

Transthoracic Echocardiography in Prone Patients With Acute Respiratory Distress Syndrome: A Feasibility Study

Supplemental Digital Content is available in the text.

Objectives:

Patients with acute respiratory distress syndrome are at risk for developing cardiac dysfunction which is independently associated with worse outcomes. Transthoracic echocardiography is an ideal imaging modality for goal-directed assessment and optimization of cardiac function and volume status. Prone positioning, while demonstrated to improve oxygenation, offload the right ventricle, and reduce short-term mortality in acute respiratory distress syndrome, has previously precluded transthoracic echocardiography on these patients. The purpose of this study was to assess the ability to perform focused transthoracic echocardiography examinations on acute respiratory distress syndrome patients in the prone position.

Design:

We performed a cross-sectional study of critically ill patients hospitalized for acute respiratory distress syndrome due to coronavirus disease 2019.

Setting:

This study was conducted in medical and surgical intensive units in a tertiary hospital.

Patients:

We examined 27 mechanically ventilated and prone patients with acute respiratory distress syndrome due to coronavirus disease 2019. Participants were examined at the time of enrollment in an ongoing clinical trial (NCT04306393), and no patients were excluded from echocardiographic analysis.

Interventions:

None.

Measurements and Main Results:

We were able to perform transthoracic echocardiography and obtain satisfactory images for quantitative assessment of right ventricular function in 24 out of 27 (88.9%) and left ventricular function in 26 out of 27 (96.3%) of patients in the prone position, including many who were obese and on high levels of positive end-expiratory pressure (≥ 15 cm H₂O).

Conclusions:

Transthoracic echocardiography can be performed at the prone patient’s bedside by critical care intensivists. These findings encourage the use of focused transthoracic echocardiography for goal-directed cardiac assessment in acute respiratory distress syndrome patients undergoing prone positioning.

An Examination of Medical Malpractice Claims Involving Physician Trainees

PURPOSE

To identify patient-, provider-, and claim-related factors of medical malpractice claims in which physician trainees were directly involved in the harm events.

METHOD

The authors performed a case-control study using medical malpractice claims closed between 2012-2016 and contributed to the Comparative Benchmarking System database by teaching hospitals. Using the service extender flag, they classified claims as cases if physician trainees were directly involved in the harm events. They classified claims as controls if they were from the same facilities, but trainees were not directly involved in the harm events. They performed multivariable regression with predictor variables being patient and provider characteristics. The outcome was physician trainee involvement in harm events.

RESULTS

From the original pool of 30,973 claims, there were 581 cases and 2,610 controls. The majority of cases involved residents (471, 81%). Cases had a statistically significant higher rate of having a trainee named as defendants than controls (184, 32% vs 233, 9%; P < .001). The most common final diagnosis for cases was puncture or laceration during surgery (62, 11%). Inadequate supervision was a contributing factor in 140 (24%) cases overall, with the majority (104, 74%) of these claims being procedure related. Multivariable regression analysis revealed that trainees were most likely to be involved in harm events in specialties such as oral surgery/dentistry and obstetrics-gynecology (OR = 7.99, 95% CI 2.93, 21.83 and OR = 1.85, 95% CI 1.24, 2.66, respectively), when performing procedures (OR = 1.58, 95% CI 1.27, 1.96), or when delivering care in the emergency room (OR = 1.65, 95% CI 1.43, 1.91).

CONCLUSIONS

Among claims involving physician trainees, procedures were common and often associated with inadequate supervision. Training directors of surgical specialties can use this information to improve resident supervision policies. The goal is to reduce the likelihood of future harm events.