Successful Management of Coronavirus Disease 2019-Related Respiratory Failure Using High-Flow Nasal Cannula Therapy in a Patient with Underlying Pulmonary Artery Hypertension.

A case involving a 50-year-old woman (height, 155 cm; weight, 79.6 kg), who was undergoing home oxygen therapy (3.5 L/min), with an oxygen saturation (SpO2) of approximately 91% due to pulmonary artery hypertension (PAH) with mixed connective tissue disease, is reported. The patient developed coronavirus disease 2019- (COVID-19-) related respiratory failure, with an SpO2 of 78% on oxygen inhalation (3.5 L/min) and was admitted to the authors' hospital. In accordance with remdesivir, dexamethasone, and heparin treatment, high-flow nasal cannula (HFNC) therapy was selected to avoid intubation. At an initial HFNC setting of 70% oxygen with a flow rate of 50 L/min, SpO2 improved to 92% and her subjective symptoms improved. She was weaned from HFNC on day 5 of admission (day 14 of COVID-19 onset) and discharged home on day 14 of admission. In patients with PAH, the beneficial effects of HFNC to avoid endotracheal intubation were evident in avoiding hemodynamic instability and worsening respiratory failure.

Risk factors associated with increased incidences of catheter-related bloodstream infection.

We have implemented several preventive measures to reduce central line-associated bloodstream infection (CLABSI) in the general intensive care unit (ICU) of a university hospital in Japan. Here, we analyzed the factors associated with CLABSI in patients with central venous catheter (CVC) insertions and evaluated the effects of our implemented preventive measures. From July 2013 to June 2018, data was collected from the medical records of 1472 patients with 1635 CVC insertions, including age, sex, Acute Physiology and Chronic Health Evaluation II (APACHE II) score, duration of ICU stay, duration of catheter insertion, insertion site, and mechanical ventilation status. During weekly conferences, a surveillance team comprising intensive care and infection control doctors and nurses determined the patients' CLABSI status. The analyzed factors were compared between CLABSI and central line patients without bloodstream infection. Multivariate analysis revealed three factors associated with CLABSI. Adjusted odds ratios with 95% confidence intervals were as follows: duration of ICU stay, 1.032 (1.019-1.044); duration of catheter insertion, 1.041 (1.015-1.066); and APACHE II score, 1.051 (1.000-1.105). The prominent risk factors were associated with the severity of the initial condition and exacerbation of the clinical condition of the patients during their stays in the ICU. Further strategies to reduce CLABSI must be developed.

Accuracy of pulse oximeters in detecting hypoxemia in patients with chronic thromboembolic pulmonary hypertension.

PURPOSE: Pulse oximetry is routinely used to continuously and non-invasively monitor arterial oxygen saturation (SaO2). When oxygen saturation by pulse oximeter (SpO2) overestimates SaO2, hypoxemia may be overlooked. We compared the SpO2 - SaO2 differences among three pulse oximeters in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who spent their daily lives in a poor oxygen state. MATERIAL AND METHOD: This prospective observational study recruited 32 patients with CTEPH undergoing elective cardiac catheterization. As we collected arterial blood samples in the catheter laboratory, SpO2 values were simultaneously recorded. Three pulse oximeters were used on each patient, and SpO2 values were compared with oximetry readings using a blood gas analyzer. To determine the optimal SpO2 value by which to detect hypoxemia (SaO2≦90%), we generated receiver operating characteristic (ROC) curves for each pulse oximeter. RESULT: The root mean square of each pulse oximeter was 1.79 (OLV-3100), 1.64 (N-BS), and 2.50 (Masimo Radical). The mean bias (SpO2 - SaO2) for the 90%-95% saturation range was significantly higher for Masimo Radical (0.19 +/- 1.78% [OLV-3100], 0.18 +/- 1.63% [N-BS], and 1.61 +/- 1.91% [Masimo Radical]; p<0.0001). The optimal SpO2 value to detect hypoxemia (SaO2≦90%) was 89% for OLV-3100, 90% for N-BS, and 92% for Masimo Radical. CONCLUSION: We found that the biases and precision with which to detect hypoxemia differed among the three pulse oximeters. To avoid hypoxemia, the optimal SpO2 should be determined for each pulse oximeter.

High-Flow Nasal Cannula Therapy in a Patient with Reperfusion Pulmonary Edema following Percutaneous Transluminal Pulmonary Angioplasty.

A 62-year-old woman with Wolff-Parkinson-White syndrome was with recent worsening of dyspnea to New York Heart Association functional status Class III. The patient was diagnosed as having central type chronic thromboembolic pulmonary hypertension. By cardiac catheterization, her mean pulmonary artery pressure was 53 mmHg with total pulmonary resistance 2238 dynes·sec·cm(-5). After medical therapies with tadalafil, furosemide, ambrisentan, beraprost, and warfarin were initiated, percutaneous transluminal pulmonary angioplasty (PTPA) was performed. Following PTPA, life-threating hypoxemia resulting from postoperative reperfusion pulmonary edema developed. High-flow nasal cannula therapy (HFNC) was applied, and 100% oxygen at 50 L/min of flow was required to keep oxygenation. HFNC was continued for 3 days, and the patient was discharged on 8th postoperative day with SpO2 of 97% on 3 L/min of oxygen inhalation. Because of the simplicity of the technique, the lower cost of equipment, and remarkable patient tolerance to the treatment, we speculate that HFNC can take over the post of noninvasive ventilation as first-line therapy for patients with acute respiratory failure.

Scheduled perioperative switch from oral sildenafil to intravenous epoprostenol in a patient with Eisenmenger syndrome undergoing a sigmoidectomy.

The perioperative management of pulmonary hypertension in a patient with Eisenmenger syndrome, the most advanced form of associated pulmonary artery hypertension (PAH), who required a sigmoidectomy is presented. The treatment for pulmonary hypertension was switched from oral sildenafil to intravenous epoprostenol to avoid the unexpected discontinuation of vasodilation during the perioperative period. The scheduled perioperative conversion should be considered for patients with severe PAH undergoing major abdominal surgery to ensure the stabilization of pulmonary and systemic hemodynamics.

Noninvasive Positive Pressure Ventilation against Reperfusion Pulmonary Edema following Percutaneous Transluminal Pulmonary Angioplasty.

A 69-year-old man with chronic thromboembolic pulmonary hypertension (CTEPH) was on amblatory oxygen inhalation therapy (3 L/min) and scheduled for percutaneous transluminal pulmonary angioplasty (PTPA). The patient's New York Heart Association functional status was class III with recent worsening of dyspnea and apparent leg edema. Transthoracic echocardiography revealed right ventricular enlargement with mean pulmonary artery pressure of 42 mmHg. After PTPA, he was complicated with postoperative reperfusion pulmonary edema, and noninvasive positive pressure ventilation (NPPV) was applied immediately. Hypoxemia was successfully treated with 15 days of NPPV. Although mean pulmonary artery pressure was unchanged, his brain natriuretic peptide level decreased from preoperative 390.3 to postoperative 44.3 pg/dL. In addition, total pulmonary resistance decreased from preoperative 18 to postoperative 9.6 wood unit·m(2). The patient was discharged on day 25 with SpO(2) of 95% on 5 L/min of oxygen inhalation. Because pulmonary edema is a postsurgical life-threatening complication following PTPA, application of NPPV should be considered.

Neutrophil depletion attenuates interleukin-8 production in mild-overstretch ventilated normal rabbit lung.

OBJECTIVE: Acute lung injury induced by lung overstretch is associated with neutrophil influx, but the pathogenic role of neutrophils in overstretch-induced lung injury remains unclear. DESIGN: To assess the contribution of neutrophils, we compared the effects of noninjurious large tidal volume (Vt) ventilation on lungs in normal and neutrophil-depleted animals. SETTING: Research animal laboratory. SUBJECTS: Twenty-six male Japanese white rabbits. INTERVENTIONS: Animals were mechanically ventilated for 4 hrs with one of the three following protocols: large Vt (20 mL/kg), small Vt (8 mL/kg), and large Vt (20 mL/kg) with neutrophil depletion achieved by a single dose of vinblastine injection (0.75 mg/kg) intravenously 4 days before the experiment. MEASUREMENTS AND MAIN RESULTS: Large Vt ventilation produced alveolar neutrophil influx compared with low Vt (p =.002) without evidence of edema or increased epithelial permeability. The neutrophil influx was accompanied by increases in interleukin-8 in bronchoalveolar lavage fluid (p =.04). Immunohistochemistry of large Vt lungs showed increased interleukin-8 staining in bronchial epithelial cells, alveolar epithelium, alveolar macrophages, and smooth muscles of pulmonary vessels. Neutrophil depletion attenuated the interleukin-8 increase in the lung. Large Vt did not increase plasma interleukin-8 or tumor necrosis factor-alpha in plasma and bronchoalveolar lavage fluid. No expression of p-selectin or intercellular adhesion molecule-1 was observed. CONCLUSIONS: Cyclic overstretching of normal rabbit lungs with noninjurious large Vt produced neutrophil influx and interleukin-8 increase in bronchoalveolar lavage fluid. Production of pulmonary interleukin-8 by lung overstretch might require the interaction between resident lung cells and migrated neutrophils. This study suggests that large Vt ventilation potentiates the predisposed, subclinical lung injury, such as nosocomial pneumonia or aspiration of gastric contents.