Bench Assessment of Work of Breathing During a Spontaneous Breathing Trial on Zero Pressure Support and Zero PEEP Compared to T-Piece.

BACKGROUND: Analysis of observational data suggests that both a T-piece and zero pressure support ventilation (PSV) and zero PEEP impose work of breathing (WOB) during a spontaneous breathing trial (SBT) similar to what a patient experiences after extubation. The aim of our study was to compare the WOB imposed by the T-piece with zero PSV and zero PEEP. We also compared the difference in WOB when using zero PSV and zero PEEP on 3 different ventilators. METHODS: This study was conducted by using a breathing simulator that simulated 3 lung models (ie, normal, moderate ARDS, and COPD). Three ventilators were used and set to zero PSV and zero PEEP. The outcome variable was WOB expressed as mJ/L of tidal volume. RESULTS: An analysis of variance showed that WOB was statistically different between the T-piece and zero PSV and zero PEEP on all the ventilators (Servo-i, Servo-u, and Carescape R860). The absolute difference was lowest for the Carescape R860, which increased WOB by 5-6%, whereas the highest for Servo-u, which reduced the WOB by 15-21%. CONCLUSIONS: Work may be imposed or reduced during spontaneous breathing on zero PSV and zero PEEP when compared to T-piece. The unpredictable nature of how zero PSV and zero PEEP behaves on different ventilators makes it an imprecise SBT modality in the context of assessing extubation readiness.

Human Metapneumovirus Pneumonia Precipitating Acute Respiratory Distress Syndrome in an Adult Patient.

Acute respiratory distress syndrome (ARDS) is often due to direct lung injury, trauma, surgery, or infection. Making a definitive diagnosis may be difficult initially, as clinical manifestations are nonspecific until the disease progresses. We present a case of human metapneumovirus (hMPV) pulmonary infection precipitating ARDS. A 51-year-old woman presented with one week of pleuritic chest pain, dyspnea, wheezing, subjective fever, and productive cough prior to presentation. Her medical history was significant for human immunodeficiency virus (HIV) with an unknown CD4 count and viral load, pulmonary sarcoidosis, asthma, and being an active smoker. On admission, the patient was dyspneic and using accessory muscles to breathe. She was afebrile and hypotensive. Physical examination revealed bilateral diffuse crackles. Her white blood cell (WBC) count was 7.7 K/mcL. A chest radiograph demonstrated bilateral lung opacifications suggestive of pneumonia, possibly Pneumocystis jiroveci pneumonia (PJP). Broad-spectrum antibiotics, including PJP treatment, corticosteroids, and fluids, were started. The patient received approximately 4 liters of intravenous fluids; yet, she remained hypotensive and required norepinephrine. Chest computed tomography (CT) demonstrated bilateral consolidations. Arterial blood gas (ABG) showed a partial pressure of oxygen (PaO2) of 55 mmHg. The patient was intubated for acute hypoxemic respiratory failure and had a PaO2/fraction of inspired oxygen (FiO2) < 100. Repeat ABG within 12 hours showed a potential of hydrogen (pH) of 7.34, partial pressure of carbon dioxide (pCO2) of 42 mmHg, and a PaO2 of 130 mmHg. Bronchoalveolar lavage revealed only hMPV. The patient was managed supportively and extubated three days later. She was discharged home without oxygen requirement. hMPV causes respiratory infections, most commonly in the extremes of age and immunocompromised patients. The treatment is supportive. Our patient developed acute hypoxemic respiratory failure secondary to an hMPV infection. hMPV pneumonia should be considered as a differential diagnosis in patients with severe respiratory illness and ARDS in order to promote antibiotic stewardship.

Preoperative Pulmonary Risk Assessment.

Postoperative pulmonary complications have a significant impact on perioperative morbidity and mortality and contribute substantially to health care costs. Surgical stress and anesthesia lead to changes in respiratory physiology, altering lung volumes, respiratory drive, and muscle function that can cumulatively increase the risk of postoperative pulmonary complications. Preoperative medical evaluation requires a structured approach to identify patient-, procedure-, and anesthesia-related risk factors for postoperative pulmonary complications. Validated risk prediction models can be used for risk stratification and to help tailor the preoperative investigation. Optimization of pulmonary comorbidities, smoking cessation, and correction of anemia are risk-mitigation strategies. Lung-protective ventilation, moderate PEEP application, and conservative use of neuromuscular blocking drugs are intra-operative preventive strategies. Postoperative early mobilization, chest physiotherapy, oral care, and appropriate analgesia speed up recovery. High-risk patients should receive inspiratory muscle training prior to surgery, and there should be a focus to minimize surgery time.

Use of nebulized naloxone to reverse methadone overdose - A case report and review of literature.

Opioid use is a frequent cause of morbidity and mortality in the USA. We report a case of methadone overdose reversed with naloxone nebulization. Peripheral IV access can be difficult to obtain in patients with a history of IV drug abuse making needless routes of naloxone administration useful. When naloxone is administered as a bolus, chronically opioid dependent patients are more prone to violent withdrawal symptoms. When successful, nebulized naloxone reverses intoxication and allows the patient to self-titrate the discontinuation of naloxone when they are alert enough to remove the mask. Nebulized naloxone can provide needleless and noninvasive administration for the reversal of opioid overdose.

EOLIA trial: the future of extracorporeal membrane oxygenation in acute respiratory distress syndrome therapy?

In the EOLIA trial, early use of ECMO did not significantly improve mortality at 60 days in patients with severe ARDS, but when used as a rescue modality ECMO might help improve survival http://bit.ly/2XOjwSE.

Meropenem-induced Stevens-Johnson syndrome/toxic epidermal necrolysis in a patient with known type IV penicillin hypersensitivity.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are considered variants of a disease continuum that results in a life-threatening exfoliative mucocutaneous disease. These are categorised as type IV cell-mediated delayed hypersensitivity reactions, and antibiotics are often implicated as a cause. Penicillins and other beta-lactam antibiotics are known to cause both immediate and delayed hypersensitivity reactions. While immediate IgE-mediated cross-reactivity between penicillins and carbapenems is well studied, less information on the risk of type IV delayed cell-mediated cross-reactivity between the two is available. We present a case of meropenem-induced SJS in a patient with documented history of SJS from amoxicillin. There are few cases of cross-reactivity with carbapenems reported in the literature, but based on the potential for life-threatening reaction, it is likely prudent to avoid the use of any beta-lactams in a patient with a history of SJS, TEN or any other severe cutaneous adverse reactions to another beta-lactam antibiotic.

Chronic cough and cystic lung disease caused by Bordetella bronchiseptica in a patient with AIDS.

A 24-year-old man with a history of HIV and large B cell lymphoma (currently in remission) presented with fever, dry cough and dizziness. His CD4+ count was undetectable, and the HIV viral load was 109 295 cop/mL. Physical examination revealed fever, hypotension and tachycardia with coarse breath sounds in the middle and lower chest zones bilaterally. Chest imaging showed diffuse abnormal micronodular and patchy infiltrates, without focal consolidation. A cavitary lesion was noted measuring 5×2 cm in axial dimensions within the left lower lobe and multiple small cystic lesions in the background. Bronchoalveolar lavage fluid culture grew Bordetella bronchiseptica The patient was empirically treated with vancomycin and piperacillin-tazobactam for multifocal pneumonia with concerns for sepsis and was started on combined antiretroviral therapy (cART) with abacavir/dolutegravir/lamivudine. Symptoms improved after day 3 of therapy, and the patient was discharged home on 2 weeks of moxifloxacin, in addition to the cART and appropriate chemoprophylaxis.