Background It can be challenging for clinicians to predict which patients with respiratory failure secondary to coronavirus disease 2019 (COVID-19) will fail on high-flow nasal cannula (HFNC) oxygen and require escalation of therapy. This study set out to evaluate the association between the respiratory rate-oxygenation index (ROX) and HFNC failure in such patients and to assess whether ROX trajectory correlates with treatment failure.
Methods This was a single-centre, retrospective, observational study of patients with COVID-19 requiring HFNC, conducted over a 3-month period. ROX was calculated as “pulse-oximetry oxygen saturation (SpO2) over the fractional inspired oxygen concentration (FiO2)/respiratory rate” for each patient at 2, 4, and 12 hours from starting HFNC. HFNC failure was defined as escalation to continuous positive airway pressure ventilation or invasive mechanical ventilation (IMV). Time-to-event analyses were performed to account for the longitudinal data set and time-dependent variables.
Results We included 146 patients. Ninety-three (63.7%) experienced HFNC failure, with 53 (36.3%) requiring IMV. Higher ROX values were associated with a lower subhazard of HFNC failure on time-to-HFNC failure analysis (subhazard ratio, 0.29; 95% confidence interval [CI], 0.18–0.46; P<0.001). This remained true after controlling for informative censoring. Median ROX values changed differentially over time, increasing in the HFNC success group (0.06 per hour; 95% CI, 0.05–0.08; P<0.001) but not in the HFNC failure group (0.004 per hour; 95% CI, –0.05 to 0.08; P=0.890).
Conclusions A higher ROX is associated with a lower risk of HFNC failure. Monitoring ROX trajectory over time may help identify patients at risk of treatment failure. This has potential clinical applications; however, future prospective studies are required.
Background The study aimed to describe the clinical course, outcomes, and prognostic factors of chronic obstructive pulmonary disease (COPD) patients with acute hypercapnic respiratory failure. Methods: This retrospective study involved patients with acute hypercapnic respiratory failure due to COPD of any cause admitted to the intensive care unit (ICU) for non-invasive or invasive mechanical ventilation (IMV) support between December 2015 and February 2020. Results: One hundred patients were evaluated. The main causes of acute hypercapnic respiratory failure were bronchitis, pneumonia, and heart failure. The patients’ mean Acute Physiology and Chronic Health Evaluation (APACHE) II score was 23.0±7.2, and their IMV rate was 43%. ICU, in-hospital, and 90-day mortality rates were 21%, 29%, and 39%, respectively. Non-survivors had more pneumonia, shock within the first 24 hours of admission, IMV, vasopressor use, and renal replacement therapy, along with higher APACHE II scores, lower admission albumin levels and PaO2/ FiO2 ratios, and longer ICU and hospital stays than survivors. Logistic regression analysis identified APACHE II score (odds ratio [OR], 1.157; 95% confidence interval [CI], 1.017–1.317; P=0.026), admission PaO2/FiO2 ratio (OR, 0.989; 95% CI, 0.978–0.999; P=0.046), and vasopressor use (OR, 8.827; 95% CI, 1.650–47.215; P=0.011) as predictors of ICU mortality. APACHE II score (OR, 1.099; 95% CI, 1.021–1.182; P=0.011) and admission albumin level (OR, 0.169; 95% CI, 0.056–0.514; P=0.002) emerged as predictors of 90-day mortality. Conclusions: APACHE II scores, the PaO2/FiO2 ratio, vasopressor use, and albumin levels are significant short-term mortality predictors in severely ill COPD patients with acute hypercapnic respiratory failure.
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COPD Exacerbation: Why It Is Important to Avoid ICU Admission Irene Prediletto, Gilda Giancotti, Stefano Nava Journal of Clinical Medicine.2023; 12(10): 3369. CrossRef
Background Acute respiratory failure (ARF) is commonly managed with invasive mechanical ventilation (IMV). The majority of the time that a patient spends on IMV is in the process of weaning. Prediction of the weaning outcome is of paramount importance, as untimely/delayed extubation is associated with a high risk of mortality. Diaphragmatic ultrasonography is a promising tool in the intensive care unit, and its utility in predicting the success of weaning remains understudied.
Methods In this prospective-observational study, we recruited 54 ARF patients on IMV, along with 50 healthy controls. During a spontaneous breathing trial, all subjects underwent diaphragmatic ultrasonography along with a rapid shallow breathing index (RSBI) assessment.
Results The mean age was 41.8±17.0 and 37.6±10.5 years among the cases and control group, respectively. Demographic variables were broadly similar in the two groups. The most common cause of ARF was obstructive airway disease. The average duration of IMV was 5.41±2.81 days. Out of 54 subjects, 45 were successfully weaned, while nine patients failed weaning. Age, body mass index, and severity of disease were similar in the successful and failed weaning patients. The sensitivity in predicting successful weaning of percent change in diaphragmatic thickness (Δtdi%) >29.71% was high (93.33%), while specificity was 66.67%. The sensitivity and specificity of mean diaphragmatic thickness (tdi) end-expiratory >0.178 cm was 60.00% and 77.78%, respectively. RSBI at 1 minute of <93.75 had an equally high sensitivity (93.33%) but a lower specificity (22.22%). Similar results were also found for RSBI measured at 5 minutes.
Conclusions During the weaning assessment, the purpose is to minimize both premature as well as delayed extubation. We found that diaphragmatic ultrasonography, in particular Δtdi%, is better than RSBI in predicting weaning outcomes.
The high-flow nasal cannula (HFNC) has been recently used in several clinical settings for oxygenation in adults. In particular, the advantages of HFNC compared with low-flow oxygen systems or non-invasive ventilation include enhanced comfort, increased humidification of secretions to facilitate expectoration, washout of nasopharyngeal dead space to improve the efficiency of ventilation, provision of a small positive end-inspiratory pressure effect, and fixed and rapid delivery of an accurate fraction of inspired oxygen (FiO2) by minimizing the entrainment of room air. HFNC has been successfully used in critically ill patients with several conditions, such as hypoxemic respiratory failure, hypercapneic respiratory failure (exacerbation of chronic obstructive lung disease), post-extubation respiratory failure, pre-intubation oxygenation, and others. However, the indications are not absolute, and much of the proven benefit remains subjective and physiologic. This review discusses the practical application and clinical uses of HFNC in adults, including its unique respiratory physiologic effects, device settings, and clinical indications.
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Background Use of a high-flow nasal cannula (HFNC) reduced postextubation respiratory failure (PERF) and reintubation rate compared to use of a low-flow oxygen system (LFOS) in low-risk patients. However, no obvious conclusion was reached for high-risk patients. Here, we sought to present the current status of HFNC use as adjunctive oxygen therapy in a clinical setting and to elucidate the nature of the protective effect following extubation.
Methods The medical records of 855 patients who were admitted to the intensive care unit of single university hospital during a period of 5.5 years were analyzed retrospectively, with only 118 patients ultimately included in the present research. The baseline characteristics of these patients and the occurrence of PERF and reintubation along with physiologic changes were analyzed.
Results Eighty-four patients underwent HFNC, and the remaining 34 patients underwent conventional LFOS after extubation. Physicians preferred HFNC to LFOS in the face of highrisk features including old age, neurologic disease, moderate to severe chronic obstructive pulmonary disease, a long duration of mechanical ventilation, low baseline arterial partial pressure of oxygen to fraction of inspired oxygen ratio, and a high baseline alveolar–arterial oxygen difference. The reintubation rate at 72 hours after extubation was not different (9.5% vs. 8.8%; P=1.000). Hypoxic respiratory failure was slightly higher in the nonreintubation group than in the reintubation group (31.9% vs. 6.7%; P=0.058). Regarding physiologic effects, heart rate was only stabilized after 24 hours of extubation in the HFNC group.
Conclusions No difference was found in the occurrence of PERF and reintubation between both groups. It is worth noting that similar PERF and reintubation ratios were shown in the HFNC group in those with certain exacerbating risk factors versus not. Caution is needed regarding delayed reintubation in the HFNC group.
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This review article shows the potential of lung ultrasound in the critically ill (LUCI) to study lung sliding and describes the optimal equipment for its assessment. Then, it analyses the integration of lung sliding within lung ultrasound then whole body critical ultrasound. It describes the place of lung sliding in the BLUE-protocol (bedside lung ultrasound in emergency) (lung and venous ultrasound for diagnosing acute respiratory failure), the FALLS-protocol (fluid administration limited by lung sonography) (the role of lung sliding in circulatory failure), and the SESAME-protocol (sequential assessment of sonography assessing mechanism or origin of severe shock of indistinct cause) (whole body ultrasound in cardiac arrest). In the LUCIFLR project (LUCI favoring limitation of radiations), the consideration of lung sliding allows drastic reduction in irradiation and costs. In conclusion, lung sliding is proposed as a gold standard for indicating the presence of the lung at the chest wall and its correct expansion.
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Korean J Crit Care Med. 2016;31(2):162-168. Published online May 31, 2016
Pnuemocystis jirovecii pneumonia (PJP) is one of leading causes of acute respiratory failure in patients infected with human immunodeficiency virus (HIV), and the mortality rate remains high in mechanically ventilated HIV patients with PJP. There are several reported cases who received extracorporeal membrane oxygenation (ECMO) treatment for respiratory failure associated with severe PJP in HIV-infected patients. We report a patient who was newly diagnosed with HIV and PJP whose condition worsened after highly active antiretroviral therapy (HAART) initiation and progressed to acute respiratory distress syndrome requiring veno-venous ECMO. The patient recovered from PJP and is undergoing treatment with HAART. ECMO support can be an effective life-saving salvage therapy for acute respiratory failure refractory to mechanical ventilation following HAART in HIV-infected patients with severe PJP.
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Severe hyperammonemia can occur as a result of inherited or acquired liver enzyme defects in the urea cycle, among which ornithine transcarbamylase deficiency (OTCD) is the most common form. We report a very rare case of a 45-year-old Korean male who was admitted to the intensive care unit (ICU) due to severe septic shock with acute respiratory failure caused by Pneumocystis jiroveci pneumonia. During his ICU stay with ventilator care, the patient suffered from marked hyperammonemia (>1,700 μg/dL) with abrupt mental change leading to life-threatening cerebral edema. Despite every effort including continuous renal replacement therapy and use of a molecular adsorbent recirculating system (extracorporeal liver support–albumin dialysis) to lower his serum ammonia level, the patient was not recovered. The lethal hyperammonemia in the patient was later proven to be a manifestation of acquired liver enzyme defect known as OTCD, which is triggered by serious catabolic conditions, such as severe septic shock with acute respiratory failure.
We herein describe a 70-year-old woman who presented with respiratory failure due to extensive lung adenocarcinoma. Despite advanced disease, care in the intensive care unit with ventilator support was performed because she was a newly diagnosed patient and was considered to have the potential to recover after cancer treatment. Because prompt control of the cancer was needed to treat the respiratory failure, empirical treatment with an oral epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor was initiated before confirmation of EGFR-mutant adenocarcinoma, and the patient was successfully treated. Later, EGFR-mutant adenocarcinoma was confirmed.
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Pumpless extracorporeal interventional lung assist (iLA) is a rescue therapy allowing effective carbon dioxide removals and lung protective ventilator settings. Herein, we report the use of a pumpless extracorporeal iLA in a tuberculosis destroyed lung (TDL) patient with severe hypercapnic respiratory failures. A 35-year-old male patient with TDL was intubated due to CO2 retention and altered mentality.
After 11 days, Ventilator Associated Pneumonia (VAP) had developed. Despite the maximal mechanical ventilator support, his severe respiratory acidosis was not corrected.
We applied the iLA for the management of refractory hypercapnia with respiratory acidosis. This case suggests that the iLA is an effective rescue therapy for TDL patients with ventilator refractory hypercapnia.
Su Jin Lim, Donghoon Lew, Haa Na Song, You Eun Kim, Seung Jun Lee, Yu Ji Cho, Yi Yeong Jeong, Mi Jung Park, Kyoung Nyeo Jeon, Ho Cheol Kim, Jong Deog Lee, Young Sil Hwang
BACKGROUND Acute respiratory failure can occur paradoxically on initiation of anti-tuberculosis (TB) treatment in patients with pulmonary TB. This study is aimed to analyze the clinical features of anti-TB treatment induced acute respiratory failure. METHODS We reviewed the clinical and radiological characteristics of 8 patients with pulmonary tuberculosis (5 men and 3 women; mean age, 55 +/- 15.5 years) who developed acute respiratory failure following initiation of anti-TB medication and thus required mechanical ventilation (MV) in the intensive care unit (ICU). RESULTS The interval between initiation of anti-TB medication and development of MV-requiring acute respiratory failure was 2-14 days (mean, 4.4 +/- 4.39 days), and the duration of MV was 1-18 days (mean, 7.1 +/- 7.03 days). At admission, body temperature and serum levels of lactate dehydrogenase and C-reactive protein were increased. Serum levels of protein, albumin and creatinine were 5.8 +/- 0.98, 2.3 +/- 0.5 and 1.8 +/- 2.58 mg/ml, respectively.
Radiographs characterized both lung involvements in all patients. Consolidation with the associated nodule was noted in 7 patients, ground glass opacity in 2, and cavitary lesion in 4. Micronodular lesion in the lungs, suggesting miliary tuberculosis lesion, was noted in 1 patient. At ICU admissions, the ranges of the APACHE II and SOFA scores were 17-38 (mean, 28.2 +/- 7.26) and 6-14 (mean, 10.1 +/- 2.74).
The mean lung injury score was 2.8 +/- 0.5. Overall, 6 patients died owing to septic shock and multiorgan failure. CONCLUSIONS On initiation of treatment for pulmonary TB, acute respiratory failure can paradoxically occur in patients with extensive lung parenchymal involvement and high mortality.
Invasive aspergillosis is a serious threat and a leading cause of death in immunocompromised patients. Aspergillus tracheobronchitis is an infrequent but severe form of invasive pulmonary aspergillos in which the fungal infection is entirely or predominantly confined to the tracheobronchial tree. We report an extraordinary case of acute airway obstruction and respiratory failure due to Aspergillus tracheobronchitis in an immunocompromised patient. Fiberoptic bronchoscopy revealed extensive obstruction of both the main and lobar bronchus with yellowish nodules strongly adhered to the bronchial wall; both histologic examination and culture of these nodules revealed Aspergillus fumigatus. Even with early detection of an intraluminal growth of Aspergillus and prompt institution of antifungal therapy, the patient died of refractory hypoxemia a few days later. This report shows that Aspergillus tracheobronchitis should be considered in immunocompromised patients with suspected lung infection even when the main radiographic finding is atelectasis.
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Vocal cord dysfunction is characterized by the paradoxical adduction of the vocal cord during inspiration, causing relapsing wheezing or stridor, chest tightness, shortness of breath, and coughing. If the patient exhibiting symptoms of asthma is not responsive to treatment, there is a need to test whether vocal cord dysfunction is complicated by asthma. Herein, we report a case of vocal cord dysfunction with acute respiratory failure in old age with underlying disease. The patient presented with resting dyspnea, an audible wheeze, and was first diagnosed with acute exacerbation of bronchial asthma. However, her symptoms were not controlled with medical treatment and laryngoscopy showed paradoxical adduction of the vocal cords. Sudden cardiopulmonary arrest occurred after meal on the day of laryngoscopic examination. Although successful cardiopulmonary resuscitation, the patient developed ventilator-associated pneumonia, and multiple organ failure, eventually leading to death. Because the case was fatal, a report is being issued.
Pulmonary actinomycosis is an indolent and slowly progressive infectious disease, accompanied by pleural effusion and empyema in about 50% of cases. The size of the effusion is usually small, though, and it responds to appropriate antibiotics. We report a case of rapidly progressing, severe empyema leading to respiratory failure that was caused by pulmonary actinomycosis. A 57-year-old man presented with pleuritic chest pain for 5 days. The initial plain chest radiograph and CT scan showed pleural effusion. Gross pus was observed during the thoracentesis and laboratory test of pleural effusion revealed empyema. In spite of empirical antibiotics and chest tube drainage, the empyema rapidly progressed and the patient reached respiratory failure. Mechanical ventilation applied and decortication via video-assisted thoracotomy was performed.
Microscopic examination of both the pleural and adjacent lung biopsy specimen revealed actinomycosis.
BACKGROUND Pumpless interventional lung assist (iLA) uses an extracorporeal gas exchange system without any complex blood pumping technology, and has been shown to reduce CO2 tension and permit protective lung ventilation. The feasibility and safety of iLA were demonstrated in previous studies, but there has been no experience with iLA in Korea.
The purpose of this study was to evaluate the feasibility of the iLA device in terms of physiologic efficacy and safety in Korean patients with acute respiratory failure. METHODS iLA was implemented in patients with acute respiratory failure who satisfied the predefined criteria of our study. Initiation of iLA followed an algorithm for implementation, ventilator care, and monitoring. Following insertion of arterial and venous cannulas under ultrasound guidance, the physiologic and respiratory variables and incidence of adverse events were monitored. RESULTS iLA was implemented in 5 patients and the duration of iLA ranged from 7 hours to 171 hours. At 24 hours after implementation, the mean changes in pH, PaCO2, and PaO2/FiO2 ranged from 7.204 to 7.393, from 68.4 mm Hg to 33 mm Hg, and from 128.7 mm Hg to 165 mm Hg, respectively. During iLA therapy, one adverse event was observed, which presented with hematochezia without hemodynamic change. CONCLUSIONS iLA treatment produced effective removal of carbon dioxide and allowed for protective ventilation in severe respiratory failure. An iLA system can easily be installed by percutaneous cannulation, without procedural complications, and without significant adverse events necessitating discontinuation of iLA after implementation.
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