Noninvasive positive pressure in acute exacerbations of chronic obstructive pulmonary disease.

PURPOSE OF REVIEW: Noninvasive positive pressure ventilation (NIV) is standard of care for patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD). We review the most current evidence and highlight areas of uncertainty and ongoing research. We highlight key concepts for the clinician caring for patients with AECOPD which require NIV. RECENT FINDINGS: Implementation of NIV in AECOPD is not uniform in spite of the evidence and guidelines. Initiation of NIV should be done early and following protocols. Low-intensity NIV remains the standard of care, although research and guidelines are evaluating higher intensity NIV. Scores to predict NIV failure continue to be refined to allow early identification and interventions. Several areas of uncertainty remain, among them are interventions to improve tolerance, length of support and titration and nutritional support during NIV. SUMMARY: The use of NIV in AECOPD is the standard of care as it has demonstrated benefits in several patient-centered outcomes. Current developments and research is related to the implementation and adjustment of NIV.

A Framework for Developing a Multidisciplinary Approach to Prone Positioning in Acute Respiratory Distress Syndrome.

Prone position ventilation (PPV) is one of the few interventions with a proven mortality benefit in the management of acute respiratory distress syndrome (ARDS), yet it is underutilized as demonstrated by multiple large observational studies. Significant barriers to its consistent application have been identified and studied. But the complex interplay of a multidisciplinary team makes its consistent application challenging. We present a framework of multidisciplinary collaboration that identifies the appropriate patients for this intervention and discuss our institutional experience applying a multidisciplinary team to implement prone position (PP) leading up to and through the current COVID-19 pandemic. We also highlight the role of such multidisciplinary teams in the effective implementation of prone positioning in ARDS throughout a large health care system. We emphasize the importance of proper selection of patients and provide guidance on how a protocolized approach can be utilized for proper patient selection.

Successful treatment of pulmonary mucormycosis (Lichtheimia spp.) in a post-partum patient with COVID-19 ARDS requiring extra-corporeal membrane oxygenation using salvage therapy.

Case Summary: A 31-year-old female presented to a regional hospital at 27 weeks pregnant and was found to have COVID-19 ARDS. She underwent intubation and caesarian section for worsening hypoxia and non-reassuring fetal heart tones. Hypoxemia was refractory to proning requiring ECMO and transfer to a tertiary care center. Admission chest radiography showed a new right lower lobe cavitating lesion with computed tomography scan revealing a large multi-loculated cavity in the right lung and extensive bilateral ground-glass opacities. The patient was started on amphotericin and posaconazole, with final respiratory cultures growing Lichtheimia spp. Source control was discussed via possible open thoracostomy, but medical management alone was continued. Total ECMO support was 3 weeks. At the time of discharge to acute rehab, 1 month of amphotericin and posaconazole had been completed, with continuation of posaconazole. At last update, she had been discharged from rehab and was back home with her infant. Conclusion: Pulmonary mucormycosis, even in the non-ECLS population, carries a high mortality. Treatment in pulmonary disease with surgery improves mortality but is not always feasible. Salvage therapy with extended course antifungal medications may be an option for those not amendable.

Use of Airway Pressure Release Ventilation in Patients With Acute Respiratory Failure Due to COVID-19: Results of a Single-Center Randomized Controlled Trial.

OBJECTIVES: Airway pressure release ventilation is a ventilatory mode characterized by a mandatory inverse inspiratory:expiratory ratio with a very short expiratory phase, aimed to avoid derecruitment and allow spontaneous breathing. Recent basic and clinical evidence suggests that this mode could be associated with improved outcomes in patients with acute respiratory distress syndrome. The aim of this study was to compare the outcomes between airway pressure release ventilation and traditional ventilation targeting low tidal volume, in patients with severe coronavirus disease 2019. DESIGN: Single-center randomized controlled trial. SETTING: ICU of a Mexican referral center dedicated to care of patients with confirmed diagnosis of coronavirus disease 2019. PATIENTS: Ninety adult intubated patients with acute respiratory distress syndrome associated with severe coronavirus disease 2019. INTERVENTIONS: Within 48 hours after intubation, patients were randomized to either receive ventilatory management with airway pressure release ventilation or continue low tidal volume ventilation. MEASUREMENTS AND MAIN RESULTS: Forty-five patients in airway pressure release ventilation group and 45 in the low tidal volume group were included. Ventilator-free days were 3.7 (0-15) and 5.2 (0-19) in the airway pressure release ventilation and low tidal volume groups, respectively (p = 0.28). During the first 7 days, patients in airway pressure release ventilation had a higher Pao2/Fio2 (mean difference, 26 [95%CI, 13-38]; p < 0.001) and static compliance (mean difference, 3.7 mL/cm H2O [95% CI, 0.2-7.2]; p = 0.03), higher mean airway pressure (mean difference, 3.1 cm H2O [95% CI, 2.1-4.1]; p < 0.001), and higher tidal volume (mean difference, 0.76 mL/kg/predicted body weight [95% CI, 0.5-1.0]; p < 0.001). More patients in airway pressure release ventilation had transient severe hypercapnia, defined as an elevation of Pco2 at greater than or equal to 55 along with a pH less than 7.15 (42% vs 15%; p = 0.009); other outcomes were similar. Overall mortality was 69%, with no difference between the groups (78% in airway pressure release ventilation vs 60% in low tidal volume; p = 0.07). CONCLUSIONS: In conclusion, when compared with low tidal volume, airway pressure release ventilation was not associated with more ventilator-free days or improvement in other relevant outcomes in patients with severe coronavirus disease 2019.

Multicenter Study of Temporal Changes and Prognostic Value of a CT Visual Severity Score in Hospitalized Patients With Coronavirus Disease (COVID-19).

BACKGROUND. Chest CT findings have the potential to guide treatment of hospitalized patients with coronavirus disease (COVID-19). OBJECTIVE. The purpose of this study was to assess a CT visual severity score in hospitalized patients with COVID-19, with attention to temporal changes in the score and the role of the score in a model for predicting in-hospital complications. METHODS. This retrospective study included 161 inpatients with COVID-19 from three hospitals in China who underwent serial chest CT scans during hospitalization. CT examinations were evaluated using a visual severity scoring system. The temporal pattern of the CT visual severity score across serial CT examinations during hospitalization was characterized using a generalized spline regression model. A prognostic model to predict major complications, including in-hospital mortality, was created using the CT visual severity score and clinical variables. External model validation was evaluated by two independent radiologists in a cohort of 135 patients from a different hospital. RESULTS. The cohort included 91 survivors with nonsevere disease, 55 survivors with severe disease, and 15 patients who died during hospitalization. Median CT visual lung severity score in the first week of hospitalization was 2.0 in survivors with non-severe disease, 4.0 in survivors with severe disease, and 11.0 in nonsurvivors. CT visual severity score peaked approximately 9 and 12 days after symptom onset in survivors with nonsevere and severe disease, respectively, and progressively decreased in subsequent hospitalization weeks in both groups. In the prognostic model, in-hospital complications were independently associated with a severe CT score (odds ratio [OR], 31.28), moderate CT score (OR, 5.86), age (OR, 1.09 per 1-year increase), and lymphocyte count (OR, 0.03 per 1 × 109/L increase). In the validation cohort, the two readers achieved C-index values of 0.92-0.95, accuracy of 85.2-86.7%, sensitivity of 70.7-75.6%, and specificity of 91.4-91.5% for predicting in-hospital complications. CONCLUSION. A CT visual severity score is associated with clinical disease severity and evolves in a characteristic fashion during hospitalization for COVID-19. A prognostic model based on the CT visual severity score and clinical variables shows strong performance in predicting in-hospital complications. CLINICAL IMPACT. The prognostic model using the CT visual severity score may help identify patients at highest risk of poor outcomes and guide early intervention.

Endotracheal Tube Obstruction Among Patients Mechanically Ventilated for ARDS Due to COVID-19: A Case Series.

BACKGROUND: Patients with COVID-19 and ARDS on prolonged mechanical ventilation are at risk for developing endotracheal tube (ETT) obstruction that has not been previously described in patients with ARDS due to other causes. The purpose of this report is to describe a case series of patients with COVID-19 and ARDS in which ETT occlusion resulted in significant clinical consequences and to define the pathology of the obstructing material. METHODS: Incidents of ETT occlusion during mechanical ventilation of COVID-19 patients were reported by clinicians and retrospective chart review was conducted. Statistical analysis was performed comparing event rates between COVID-19 and non-COVID 19 patients on mechanical ventilation over the predefined period. Specimens were collected and submitted for pathological examination. FINDINGS: Eleven COVID-19 patients experienced endotracheal tube occlusion over a period of 2 months. Average age was 69 (14.3, range 33-85) years. Mean APACHE III score was 73.6 (17.3). All patients had AKI and cytokine storm. Nine exhibited biomarkers for hypercoagulability. Average days on mechanical ventilation before intervention for ETT occlusion was 14 (5.18) days (range of 9 to 23 days). Five patients were discharged from the ICU, and 4 expired. Average documented airway resistance on admission was 14.2 (3.0) cm H2O/L/sec. Airway resistance before tube exchange was 28.1 (8.0) cm H2O /L/sec. No similar events of endotracheal tube occlusion were identified in non-COVID patients on mechanical ventilation during the same time period. Microscopically, the material consisted of mucin admixed with necrotic cell debris, variable numbers of degenerated inflammatory cells, oral contaminants and red blood cells. INTERPRETATION: Patients with COVID-19 and ARDS on prolonged mechanical ventilation are at risk for developing ETT obstruction due to deposition of a thick, tenacious material within the tube that consists primarily of mucin and cellular debris. Clinicians should be aware of this dangerous but treatable complication.

Adherence to blood product transfusion guidelines-An observational study of the current transfusion practice in a medical intensive care unit.

BACKGROUND: Blood transfusions though life-saving are not entirely benign. They are the most overused procedure in the hospital and have been under scrutiny by the 'Choosing Wisely campaign'. The strict adoption of restrictive transfusion guidelines could improve patient outcomes while reducing cost. OBJECTIVES: In this study, we evaluate adherence to restrictive transfusion guidelines, along with hospital mortality and length of stay (LOS) in transfusion events with a pre-transfusion haemoglobin (Hb) ≥7 g/dl. Additionally, we evaluated associated costs accrued due to unnecessary transfusions. METHODS: We conducted a retrospective observational study in a 64-bed medical intensive care unit (MICU) of an academic medical centre involving all adult patients (N = 957) requiring packed red blood cell transfusion between January 2015 and December 2015. RESULTS: In total, 3140 units were transfused with a mean pre-transfusion Hb of 6.75 ± 0.86 g/dl. Nine hundred forty-four (30%) transfusion events occurred with a pre-transfusion Hb ≥7 g/dl, and 385 (12.3%) of these occurred in patients without hypotension, tachycardia, use of vasopressors, or coronary artery disease. Forgoing them could have led to a savings of approximately 0.3 million dollars. Transfusion events with pre-transfusion Hb ≥7 g/dl were associated with an increased mortality in patients with acute blood loss (odds ratio [OR] 2.08, 95% confidence interval [CI] 1.11-3.88; p = 0.02) and LOS in patients with chronic blood loss (ß1 .8.26, 95% CI 4.09-12.43; p < 0.01). CONCLUSION: A subset of anaemic patients in the MICU still receive red blood cell transfusions against restrictive guidelines offering hospitals the potential for effective intervention that has both economic and clinical implications.

A case of vaping-induced acute respiratory distress syndrome requiring extracorporeal life support.

INTRODUCTION: An upsurge of e-cigarette, or vaping, product use-associated lung injury has been reported in the United States. The potential role of extracorporeal life support in e-cigarette, or vaping, product use-associated lung injury merits consideration. CASE REPORT: We present a case of vaping-induced severe acute respiratory distress syndrome that was salvaged with extracorporeal life support and had excellent recovery. DISCUSSION: The mechanistic reasons for the sudden outbreak of e-cigarette, or vaping, product use-associated lung injury are under active investigation. A predominantly diffuse, bilateral pattern of lung injury has been reported, with some cases meeting the criteria for severe acute respiratory distress syndrome. To date, 68 deaths from e-cigarette, or vaping, product use-associated lung injury have been confirmed by the centers of disease control. However, resolution of lung injury has been reported in most cases, thereby justifying candidacy for extracorporeal life support, if required. CONCLUSION: Extracorporeal life support can be successfully utilized as a bridge to recovery in vaping-induced severe acute respiratory distress syndrome.

Noninvasive positive pressure ventilation in stable patients with COPD.

PURPOSE OF REVIEW: Long-term noninvasive positive pressure ventilation (NIV) used to be a controversial form of therapy for patients with stable hypercapnic chronic obstructive pulmonary disease (SH-COPD). New evidence described in this review defines the optimal settings, timing and target population for NIV utilization in SH-COPD necessary to maximize its benefit. RECENT FINDINGS: NIV, when titrated appropriately, leads to improved clinical outcomes. High inspiratory positive airway pressures aimed at decreasing CO2 levels can ensure NIV success in SH-COPD. NIV initiated when patients remain hypercapnic whereas in a clinical stable state following an acute exacerbation can prolong the time to a readmission. Technological advances in NIV algorithms and remote monitoring have the potential to improve use and titration. NIV and portable NIV improve exercise tolerance and may accentuate the benefits derived from pulmonary rehabilitation alone. SUMMARY: Use of high-intensity NIV in SH-COPD is beneficial yet appropriate patient selection and implementation is paramount.

The Performance of Diagnostic Criteria for Hemophagocytic Lymphohistiocytosis in Critically Ill Patients.

OBJECTIVE: The diagnostic criteria for secondary hemophagocytic lymphohistiocytosis (HLH) have not been validated in the critically ill adult population. We set out to evaluate the performance of diagnostic criteria and determine the ferritin cutoff in critically ill adults. DESIGN: A retrospective single-center study. SETTING AND PATIENTS: Patients admitted to intensive care unit between 2008 and March 2010. Data were collected on consecutive patients who had ferritin measured. Charts were reviewed for the diagnostic criteria of HLH and components of Hscore. MEASUREMENTS AND MAIN RESULTS: A total of 445 patients had a ferritin level measured during the study period. A diagnosis of HLH was made for 10 patients. Having 5 of 6 criteria had a specificity of 97% and a sensitivity of 70%. Hemophagocytosis was found in 41 (47.1%) of 87 bone marrow biopsies. Two hundred thirty-one patients had a ferritin level above 500 ng/dL. When determining the odds of HLH being clinically diagnosed, the optimal cut point for ferritin was 1197 ng/dL. When determining the odds of HLH based on the Hscore, the best cutoff was 143.5 (sensitivity of 90% and specificity of 90%) and patients who had HLH in our study population had an Hscore of 203.8 ± 64.9. CONCLUSION: In this cohort of critically ill patients, the HLH criteria are specific for HLH but not sensitive. Critically ill patients can have a higher incidence of hemophagocytosis without HLH. A higher ferritin cutoff in combination with 5 other clinical criteria is comparable to the Hscore for the recognition of HLH in the critically ill population.

Clinical predictors of renal non-recovery in acute respiratory distress syndrome.

BACKGROUND: Acute kidney injury (AKI) is the most common extra-pulmonary organ failure in acute respiratory distress syndrome (ARDS). Renal recovery after AKI is determined by several factors. The objective of this study was to determine the predictors of renal non-recovery in ARDS patients. METHODS: A single center retrospective cohort study of patients with AKI after onset of ARDS. Patients with preexisting chronic kidney disease or intensive care unit stay < 24 h were excluded. AKI staging was defined according to the Kidney Disease Improving Global Outcomes (KDIGO) 2012 guidelines. Renal non-recovery was defined as death, dialysis dependence, serum creatinine ≥1.5 times the baseline, or urine output < 0.5 mL/kg/h more than 6 h. RESULTS: Of the 244 patients that met study criteria, 60 (24.6%) had stage I AKI, 66 (27%) had stage II AKI, and 118 (48.4%) had stage III AKI. Of those, 148 (60.7%) patients had renal non-recovery. On multivariable analysis, factors associated with renal non-recovery were a higher stage of AKI (odds ratio [OR] stage II 5.71, 95% confidence interval [CI] 2.17-14.98; OR stage III 45.85, 95% CI 16.27-129.2), delay in the onset of AKI (OR 1.12, 95% CI 1.03-1.21), history of malignancy (OR 4.02, 95% CI 1.59-10.15), septic shock (OR 3.2, 95% CI 1.52-6.76), and a higher tidal volume on day 1-3 of ARDS (OR 1.41, 95% CI 1.05-1.90). Subgroup analysis of survival at day 28 of ARDS also found that higher severity of AKI (OR stage II 8.17, 95% CI 0.84-79.91; OR stage III 111.67, 95% CI 12.69-982.91), delayed onset of AKI (OR 1.12, 95% CI 1.02-1.23), and active malignancy (OR 6.55, 95% CI 1.34-32.04) were significant predictors of renal non-recovery. CONCLUSIONS: A higher stage of AKI, delayed onset of AKI, a history of malignancy, septic shock, and a higher tidal volume on day 1-3 of ARDS predicted renal non-recovery in ARDS patients. Among survivors, a higher stage of AKI, delayed onset of AKI, and a history of malignancy were associated with renal non-recovery.

Correction to: Clinical predictors of renal non-recovery in acute respiratory distress syndrome.

Following publication of the original article.

Neuromuscular weakness in chronic obstructive pulmonary disease: chest wall, diaphragm, and peripheral muscle contributions.

PURPOSE OF REVIEW: Chronic obstructive lung disease affects the lung parenchyma and airways leading to well described effects in respiratory function. This review describes the current knowledge and advances regarding neuromuscular function and chest wall mechanics, which are affected in chronic obstructive pulmonary disease (COPD). RECENT FINDINGS: In COPD, progressive lung hyperinflation becomes constrained by a chest wall with decreasing capacity to expand, resulting in respiratory muscle inefficiency. There is evidence of neuromuscular uncoupling, that is, the respiratory muscle is unable to increase its output in proportion to increasing neural signals. COPD patients also have evidence of altered peripheral muscles function. The end effect of all these pathological changes is neuromuscular weakness. SUMMARY: Respiratory and peripheral muscles dysfunction is found in patients with COPD. This manifests clinically as dyspnea, poor exercise capacity, and decreased quality of life. We have clear evidence that rehabilitation helps several aspects of patients with COPD. Further understanding of the physiopathology is needed to improve our therapeutic and rehabilitation strategies.

Revisiting Ultrasound-Guided Subclavian/Axillary Vein Cannulations: Importance of Pleural Avoidance With Rib Trajectory.

The Centers for Disease Control and Prevention guidelines for the prevention of catheter-related bloodstream infections suggest using "a subclavian site, rather than an internal jugular or a femoral site, in adult patients." This recommendation is based on evidence of lower rates of thrombosis and catheter-related bloodstream infections in patients with subclavian central venous catheters (CVCs) compared to femoral or internal jugular sites. However, preference toward a subclavian approach to CVC insertion is hindered by increased risk of mechanical complications, especially pneumothorax, when compared to other sites. This is largely related to the proximity of the subclavian vein to the pleural space and the traditional "blind" or anatomic landmark approach used in subclavian vein cannulation. We revisit a method that may provide increased safety and avoidance of pneumothorax during ultrasound-guided subclavian/axillary vein cannulation. This is achieved by directing the needle toward the subclavian vein at a point where it traverses over the second rib, providing a protective rib shield between the vessel and pleura as a safety net for operators. The technique also allows for increased compressibility of the subclavian/axillary vein in the event of bleeding complication.

Peripheral Administration of Norepinephrine: A Prospective Observational Study.

BACKGROUND: Historically, norepinephrine has been administered through a central venous catheter (CVC) because of concerns about the risk of ischemic tissue injury if extravasation from a peripheral IV catheter (PIVC) occurs. Recently, several reports have suggested that peripheral administration of norepinephrine may be safe. RESEARCH QUESTION: Can a protocol for peripheral norepinephrine administration safely reduce the number of days a CVC is in use and frequency of CVC placement? STUDY DESIGN AND METHODS: This was a prospective observational cohort study conducted in the medical ICU at a quaternary care academic medical center. A protocol for peripheral norepinephrine administration was developed and implemented in the medical ICU at the study site. The protocol was recommended for use in patients who met prespecified criteria, but was used at the treating clinician's discretion. All adult patients admitted to the medical ICU receiving norepinephrine through a PIVC from February 2019 through June 2021 were included. RESULTS: The primary outcome was the number of days of CVC use that were avoided per patient, and the secondary safety outcomes included the incidence of extravasation events. Six hundred thirty-five patients received peripherally administered norepinephrine. The median number of CVC days avoided per patient was 1 (interquartile range, 0-2 days per patient). Of the 603 patients who received norepinephrine peripherally as the first norepinephrine exposure, 311 patients (51.6%) never required CVC insertion. Extravasation of norepinephrine occurred in 35 patients (75.8 events/1,000 d of PIVC infusion [95% CI, 52.8-105.4 events/1,000 d of PIVC infusion]). Most extravasations caused no or minimal tissue injury. No patient required surgical intervention. INTERPRETATION: This study suggests that implementing a protocol for peripheral administration of norepinephrine safely can avoid 1 CVC day in the average patient, with 51.6% of patients not requiring CVC insertion. No patient experienced significant ischemic tissue injury with the protocol used. These data support performance of a randomized, prospective, multicenter study to characterize the net benefits of peripheral norepinephrine administration compared with norepinephrine administration through a CVC.

Survey of Ventilator Waveform Interpretation Among ICU Professionals.

BACKGROUND: The interpretation of ventilator waveforms is essential for effective and safe mechanical ventilation but requires specialized training and expertise. This study aimed to investigate the ability of ICU professionals to interpret ventilator waveforms, identify areas requiring further education and training, and explore the factors influencing their interpretation skills. METHODS: We conducted an international online anonymous survey of ICU professionals (physicians, nurses, and respiratory therapists [RTs]), with ≥ 1 y of experience working in the ICU. The survey consisted of demographic information and 15 multiple-choice questions related to ventilator waveforms. Results were compared between professions using descriptive statistics, and logistic regression (expressed as odds ratios [ORs; 95% CI]) was performed to identify factors associated with high performance, which was defined by a threshold of 60% correct answers. RESULTS: A total of 1,832 professionals from 31 countries or regions completed the survey; 53% of respondents answered ≥ 60% of the questions correctly. The 3 questions with the most correct responses were related to waveforms that demonstrated condensation (90%), pressure overshoot (79%), and bronchospasm (75%). Conversely, the 3 questions with the fewest correct responses were waveforms that demonstrated early cycle leading to double trigger (43%), severe under assistance (flow starvation) (37%), and early/reverse trigger (31%). Factors significantly associated with ≥ 60% correct answers included years of ICU working experience (≥ 10 y, OR 1.6 [1.2-2.0], P < .001), profession (RT, OR 2.8 [2.1-3.7], P < .001), highest degree earned (graduate, OR 1.7 [1.3-2.2], P < .001), workplace (teaching hospital, OR 1.4 [1.1-1.7], P = .008), and prior ventilator waveforms training (OR 1.7 [1.3-2.2], P < .001). CONCLUSIONS: Slightly over half respondents correctly identified ≥ 60% of waveforms demonstrating patient-ventilator discordance. High performance was associated with ≥ 10 years of ICU working experience, RT profession, graduate degree, working in a teaching hospital, and prior ventilator waveforms training. Some discordances were poorly recognized across all groups of surveyed professionals.

Complex Heart-Lung Ventilator Emergencies in the CICU.

This review aims to enhance the comprehension and management of cardiopulmonary interactions in critically ill patients with cardiovascular disease undergoing mechanical ventilation. Highlighting the significance of maintaining a delicate balance, this article emphasizes the crucial role of adjusting ventilation parameters based on both invasive and noninvasive monitoring. It provides recommendations for the induction and liberation from mechanical ventilation. Special attention is given to the identification of auto-PEEP (positive end-expiratory pressure) and other situations that may impact hemodynamics and patients' outcomes.