Expiratory flow limitation during mechanical ventilation: real-time detection and physiological subtypes.

BACKGROUND: Tidal expiratory flow limitation (EFLT) complicates the delivery of mechanical ventilation but is only diagnosed by performing specific manoeuvres. Instantaneous analysis of expiratory resistance (Rex) can be an alternative way to detect EFLT without changing ventilatory settings. This study aimed to determine the agreement of EFLT detection by Rex analysis and the PEEP reduction manoeuvre using contingency table and agreement coefficient. The patterns of Rex were explored. METHODS: Medical patients ≥ 15-year-old receiving mechanical ventilation underwent a PEEP reduction manoeuvre from 5 cmH2O to zero for EFLT detection. Waveforms were recorded and analyzed off-line. The instantaneous Rex was calculated and was plotted against the volume axis, overlapped by the flow-volume loop for inspection. Lung mechanics, characteristics of the patients, and clinical outcomes were collected. The result of the Rex method was validated using a separate independent dataset. RESULTS: 339 patients initially enrolled and underwent a PEEP reduction. The prevalence of EFLT was 16.5%. EFLT patients had higher adjusted hospital mortality than non-EFLT cases. The Rex method showed 20% prevalence of EFLT and the result was 90.3% in agreement with PEEP reduction manoeuvre. In the validation dataset, the Rex method had resulted in 91.4% agreement. Three patterns of Rex were identified: no EFLT, early EFLT, associated with airway disease, and late EFLT, associated with non-airway diseases, including obesity. In early EFLT, external PEEP was less likely to eliminate EFLT. CONCLUSIONS: The Rex method shows an excellent agreement with the PEEP reduction manoeuvre and allows real-time detection of EFLT. Two subtypes of EFLT are identified by Rex analysis. TRIAL REGISTRATION: Clinical trial registered with www.thaiclinicaltrials.org (TCTR20190318003). The registration date was on 18 March 2019, and the first subject enrollment was performed on 26 March 2019.

Myeloperoxidase-antineutrophil cytoplasmic antibody-associated diffuse alveolar hemorrhage caused by denosumab.

Denosumab is a bone anti-resorptive drug, commonly used for treating osteoporosis. Pulmonary involvement has rarely been reported as a possible serious adverse effect of this medication. Herein, we report the case of a 67-year-old woman who presented with non-massive hemoptysis, anemia, and extensive pulmonary opacities on a chest radiograph for 3 days after receiving denosumab. The patient was diagnosed with myeloperoxidase-antineutrophil cytoplasmic antibody-associated pulmonary hemorrhage secondary from denosumab. She was treated with high doses of intravenous methylprednisolone and cyclophosphamide combined with plasmapheresis. Subsequently, her clinical and radiological findings improved without residual abnormalities after treatment.

Combined Pulmonary Tuberculosis with Pulmonary and Pleural Cryptococcosis in a Patient Receiving Ruxolitinib Therapy.

With an advance in therapy, there are increasing emerging and re-emerging opportunistic infections among patients with hematologic conditions and malignancy. Herein, we present a 56-year-old woman with primary myelofibrosis who developed combined tuberculosis (TB) and cryptococcosis with extensive pulmonary, pleural, and nodal involvement during ruxolitinib therapy. Marked clinical and radiologic improvements were undoubtedly evident after receiving anti-TB and antifungal therapies and pleural drainage. Hence, the presence of atypical clinical and radiologic manifestations and incomplete responses, despite receiving adequate antimicrobial treatment, should raise concerns regarding the combined emerging and re-emerging opportunistic infections and the possibility of unusual radiologic manifestations of cryptococcosis in a ruxolitinib-treated patient.