Carbonic anhydrase inhibitors in patients with respiratory failure and metabolic alkalosis: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Metabolic alkalosis is common in patients with respiratory failure and may delay weaning in mechanically ventilated patients. Carbonic anhydrase inhibitors block renal bicarbonate reabsorption, and thus reverse metabolic alkalosis. The objective of this systematic review is to assess the benefits and harms of carbonic anhydrase inhibitor therapy in patients with respiratory failure and metabolic alkalosis. METHODS: We searched the following electronic sources from inception to August 2017: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and SCOPUS. Randomized clinical trials were included if they assessed at least one of the following outcomes: mortality, duration of hospital stay, duration of mechanical ventilation, adverse events, and blood gas parameters. Teams of two review authors worked in an independent and duplicate manner to select eligible trials, extract data, and assess risk of bias of the included trials. We used meta-analysis to synthesize statistical data and then assessed the certainty of evidence using the GRADE methodology. RESULTS: Six eligible studies were identified with a total of 564 participants. The synthesized data did not exclude a reduction or an increase in mortality (risk ratio (RR) 0.94, 95% confidence interval (CI) 0.57 to 1.56) or in duration of hospital stay (mean difference (MD) 0.42 days, 95% CI -4.82 to 5.66) with the use of carbonic anhydrase inhibitors. Carbonic anhydrase inhibitor therapy resulted in a decrease in the duration of mechanical ventilation of 27 h (95% CI -50 to -4). Also, it resulted in an increase in PaO2 (MD 11.37 mmHg, 95% CI 4.18 to 18.56) and a decrease in PaCO2 (MD -4.98 mmHg, 95% CI -9.66, -0.3), serum bicarbonate (MD -5.03 meq/L, 95% CI -6.52 to -3.54), and pH (MD -0.04, 95% CI -0.07 to -0.01). There was an increased risk of adverse events in the carbonic anhydrase inhibitor group (RR 1.71, 95% CI 0.98 to 2.99). Certainty of evidence was judged to be low for most outcomes. CONCLUSION: In patients with respiratory failure and metabolic alkalosis, carbonic anhydrase inhibitor therapy may have favorable effects on blood gas parameters. In mechanically ventilated patients, carbonic anhydrase inhibitor therapy may decrease the duration of mechanical ventilation. A major limitation of this finding was that only two trials assessed this clinically important outcome.

Prediction of inspired oxygen fraction for targeted arterial oxygen tension following open heart surgery in non-smoking and smoking patients.

Simple and accurate expressions describing the PaO2-FiO2 relationship in mechanically ventilated patients are lacking. The current study aims to validate a novel mathematical expression for accurate prediction of the fraction of inspired oxygen that will result in a targeted arterial oxygen tension in non-smoking and smoking patients receiving mechanical ventilation following open heart surgeries. One hundred PaO2-FiO2 data pairs were obtained from 25 non-smoking patients mechanically ventilated following open heart surgeries. One data pair was collected at each of FiO2 of 40, 60, 80, and 100% while maintaining same mechanical ventilation support settings. Similarly, another 100 hundred PaO2-FiO2 data pairs were obtained from 25 smoking patients mechanically ventilated following open heart surgeries. The utility of the new mathematical expression in accurately describing the PaO2-FiO2 relationship in these patients was assessed by the regression and Bland-Altman analyses. Significant correlations were seen between the true and estimated FiO2 values in non-smoking (r2 = 0.9424; p < 0.05) and smoking (r2 = 0.9466; p < 0.05) patients. Tight biases between the true and estimated FiO2 values for non-smoking (3.1%) and smoking (4.1%) patients were observed. Also, significant correlations were seen between the true and estimated PaO2/FiO2 ratios in non-smoking (r2 = 0.9530; p < 0.05) and smoking (r2 = 0.9675; p < 0.05) patients. Tight biases between the true and estimated PaO2/FiO2 ratios for non-smoking (-18 mmHg) and smoking (-16 mmHg) patients were also observed. The new mathematical expression for the description of the PaO2-FiO2 relationship is valid and accurate in non-smoking and smoking patients who are receiving mechanical ventilation for post cardiac surgery.

Effect of heliox- and air-driven nebulized bronchodilator therapy on lung function in patients with asthma.

BACKGROUND: This study compares the effect of heliox-driven to that of air-driven bronchodilator therapy on the pulmonary function test (PFT) in patients with different levels of asthma severity. METHODS: One-hundred thirty-two participants were included in the study. Participants underwent spirometry twice with bronchodilator testing on two consecutive days. Air-driven nebulization was used one day and heliox-driven nebulization the other day in random order crossover design. After a baseline PFT, each participant received 2.5 mg of albuterol sulfate nebulized with the randomized driving gas. Post bronchodilator PFT was repeated after 30 min. The next day, the exact same protocol was repeated, except that the other driving gas was used to nebulize the drug. Participants were subgrouped and analyzed according to their baseline FEV(1) on day 1: Group I, FEV(1) ≥80 %; Group II, 80 % > FEV(1) > 50 %; Group III, FEV(1) ≤50 %. The proportion of participants with greater than 12 % and 200-mL increases from their baseline FEV(1) and the changes from baseline in PFT variables were compared between heliox-driven versus air-driven bronchodilation therapy. RESULTS: The proportion of participants with >12 % and 200-mL increases from their baseline FEV(1) with air- or heliox-driven bronchodilation was not different with respect to the proportion of participants with baseline FEV(1) ≥80 % (20 vs. 18 %, respectively) and 80 % > FEV(1) > 50 % (36 vs. 43 %, respectively), but it was significantly greater with heliox-driven bronchodilation in participants with FEV(1) ≤50 % (43 vs. 73 %, respectively; p = 0.01). Changes from baseline FVC, FEV(1), FEV(1)/FVC, FEF(25-75) %, FEF(max), FEF(25) %, FEF(50) %, and FEF(75) % were significantly larger with heliox-driven versus air-driven bronchodilation in participants with baseline FEV(1) ≤50 %. CONCLUSION: Improvements in PFT variables are more frequent and profound with heliox-driven compared to air-driven bronchodilator therapy only in asthmatic patients with baseline FEV(1) ≤50 %.

Obstructive sleep apnea: Beyond the dogma of obesity!

Obstructive sleep apnea (OSA) has long been studied in patients with obesity and type 2 diabetes mellitus (T2DM), due to the fact that both disorders are commonly associated with an increased body mass index (BMI). However, a link between OSA and non-obese diabetic patients is still not very elaborated, nor heavily explored. In this review, we elucidate some proposed mechanisms for the link between OSA and diabetic patients both with and beyond obesity, shedding the light on the latter case. One such mechanism is oxidative stress, a phenomenon of reactive oxygen species (ROS) imbalance seen in both of the previously mentioned disorders. A plausible explanation for the OSA-induced ROS production is the repeating episodes of hypoxia and reperfusion and their effect on the mitochondrial electron transport chain. This paper explores the literature regarding ROS imbalance as the possible missing link between OSA and Diabetes Mellitus beyond obesity, while still mentioning other possible proposed mechanisms such as a dysregulated autonomic nervous system (ANS), as well as mechanical and craniofacial abnormalities. This paper also suggests a link between OSA and diabetic complications, while exploring the clinical progress made in treating the former disorder with anti-oxidant and hypo-glycemic drugs. If further investigated, these findings could help identify novel therapeutic interventions for the treatment of OSA and Diabetic patients.

Tracheal Schwannoma Presenting as Subcutaneous Emphysema and Pneumomediastinum.

Primary tracheal schwannomas are rare benign tumours. This is a case report, and therefore, no specific methods or results are applicable. We here report a case of a tracheal schwannoma in an early adolescent girl presenting with subcutaneous emphysema and symptoms of airway obstruction. Tracheal resection and reconstruction by primary anastomosis were performed. Pathology confirmed the diagnosis of tracheal schwannoma. This is an unusual life-threatening presentation of a benign rare tracheal tumour with a challenging approach to management.

Pulmonary Edema Following Nifedipine Use in Pregnancy: A Case Report.

Calcium channel blockers are generally considered safe for use during pregnancy. They have several indications, including second-line therapy for lowering blood pressure and tocolytic therapy. We present the case of a 24-year-old woman, G1P0, with a twin gestation at 22 weeks, who presented with acute respiratory distress. Her symptoms occurred shortly after starting nifedipine as tocolytic therapy. Investigations revealed signs of volume overload and pulmonary edema. Extensive cardiac and infectious workups were normal. Obstetrical ultrasound did not show any signs of ovarian hyperstimulation syndrome. Based on these findings, she was diagnosed with acute pulmonary edema following tocolytic therapy with oral nifedipine. Nifedipine was stopped, and intravenous furosemide was started, resulting in rapid clinical improvement. We are reporting this case to raise awareness of this rare but life-threatening adverse event associated with nifedipine use in pregnant patients.

Ventilator auto-cycling from cardiogenic oscillations: case report and review of literature.

BACKGROUND: Brain death is the total loss of all brain and brain stem functions, and its diagnosis is often confirmed by an apnoea test, which relies on disconnecting the patient from the ventilator. Auto-triggering or auto-cycling is defined as a ventilator being triggered in the absence of patient effort, intrinsic respiratory drive or inspiratory muscle activity. Ventilator auto-triggering could delay the diagnosis of brain death leading to unnecessary admission for the patient and false hopes of recovery for the family. METHODS: We report a case of ventilator auto-triggering associated with cardiogenic oscillations in a female patient. RESULTS: We confirmed the finding of ventilator auto-triggering by changing the patient's position and reassessing the triggering thresholds. Brain death was then confirmed by apnoea test. CONCLUSION: This case is presented to arouse the awareness of the medical staff and nurses to this phenomenon, which can mimic an intrinsic respiratory effort in patients allegedly diagnosed with brain death. Along with this case report, we review the English language publications for similar cases.

PRevalence of the Eosinophilic Phenotype Among SeveRE asthma patients in Lebanon: results of the PREPARE study.

BACKGROUND: The prevalence of eosinophilic asthma in Lebanon, one of the most severe phenotypes among severe asthma, is not known. This study aimed at determining the prevalence of the eosinophilic phenotype defined as an eosinophil count ≥ 300 cells/mm3 among severe asthma patients in Lebanon. METHODS: The Lebanese Chapter of the PREPARE study was a national, multicenter, cross-sectional observational study. Patients aged ≥ 12 years with severe asthma were identified and prospectively enrolled during clinic visits and completed the Global Initiative for Asthma (GINA) assessment of asthma control questionnaire. Patients' health characteristics were collected from medical records and blood samples were obtained for measurement of serum IgE levels and blood eosinophils count. RESULTS: Overall, 101 patients (with mean age of 46.3 ± 17.0 years and 73.27% females) with severe asthma were included and, among them, 37% had eosinophilic phenotype, 67.3% had atopic phenotype with IgE > 100 IU/mL and 25.7% patients had overlapping atopic and eosinophilic phenotypes. Close to 80% had late-onset asthma, beyond 12 years of age, and around 85% had at least one severe exacerbation in the 12 months prior to study enrolment. The majority of participants [64.4%] had uncontrolled asthma, 24.7% had partially controlled symptoms and 10.9% had controlled symptoms. 19.8% of participants were on chronic oral corticosteroids, 78.2% had short course treatment of corticosteroids and all were prescribed a combination of inhaled corticosteroids and long-acting beta-agonist. CONCLUSIONS: The majority of patients with severe asthma were uncontrolled of which 37% present with an eosinophilic phenotype, which should be taken into consideration for better management of these patients in view of the novel phenotype-specific therapeutic options.

Weaning from mechanical ventilation.

PURPOSE OF REVIEW: Liberation from mechanical ventilation is a defining moment for intubated patients, and thus a critical clinical decision. Extubating the patient too early exposes the patient to extubation failure and reintubation. Waiting too long increases the complications of prolonged intubation. Tools to help the physician with this critical decision and to test readiness have been available for decades, and are continuously being improved. New methods to improve extubation outcomes are also being developed. This review covers the latest studies in order to help physicians take advantage of the latest developments in a rapidly evolving field. RECENT FINDINGS: This review highlights the recent advances in assessing and testing for readiness of weaning and liberation from mechanical ventilation, the cause of weaning failure, the value of weaning protocols, and the role of noninvasive positive pressure ventilation in liberating patients from invasive mechanical ventilation. SUMMARY: Recent findings are shedding more light on this topic, and transforming 'the artistic' aspect of weaning and liberation from mechanical ventilation into a more 'scientific' approach that will expedite liberation from mechanical ventilation yet without encountering high failure rates, and without exposing patients to unnecessary risks.

Outcomes of Patients with Malignancy Admitted to the Intensive Care Units: A Prospective Study.

INTRODUCTION: Decisions regarding whether advanced cancer patients should be admitted to the ICU are based on a complex suite of considerations, including short- and long-term prognosis, quality of life, and therapeutic options to treat cancer. We aimed to describe demographic, clinical, and survival data and to identify factors associated with mortality in critically ill advanced cancer patients with nonelective admissions to general ICUs. MATERIALS AND METHODS: Critically ill adult (≥18 years old) cancer patients nonelectively admitted to the intensive care units at the American University of Beirut Medical Center between August 1st 2015 and March 1st 2019 were included. Demographic, clinical, and laboratory data were prospectively collected from the first day of ICU admission up to 30 days after discharge. This study was strictly observational, and clinical decisions were left to the discretion of the ICU team and attending physician. RESULTS: 272 patients were enrolled in the study between August 1st 2015 and March 1st 2019, with an ICU mortality rate of 43.4%, with the number rising to 59% within 30 days of ICU discharge. The mean length of stay in our ICU was 14 days (IQR: 1-120) with a median overall survival of 22 days since the date of ICU admission. The major reasons for unplanned ICU admission were sepsis/septic shock (54%) and respiratory failure (33.1%). Cox regression analysis revealed 7 major predictors of poor prognosis. Direct admission from the ED was associated with a higher risk of mortality (48.9%) than being transferred from the floor (32.6%) (p=0.014). CONCLUSION: Our study has shown that being directly admitted to the ICU from the ED rather than being transferred from regular wards, developing AKI, sepsis, MOF, and ARDS, or having an uncontrolled malignancy are all predictive factors for short-term mortality in critically ill cancer patients nonelectively admitted to the ICU. Vasopressor use and mechanical ventilation were also predictors of mortality.

Persistent snoring under conscious sedation during colonoscopy is a predictor of obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea (OSA) is characterized by cessation of breathing during sleep. Conscious sedation (CS) induces sleep and may uncover sleep-related breathing disorders. OBJECTIVE: To determine whether snoring during CS is a sensitive predictor of OSA. DESIGN: Matched cohort study. SETTING: University-based ambulatory endoscopy center. PATIENTS: Consecutive patients undergoing colonoscopy completed a detailed sleep questionnaire and physical examination geared toward detecting OSA (body mass index [BMI], neck circumference, and the presence of craniofacial abnormalities). The endoscopist was blinded to the information. INTERVENTIONS: Portable nocturnal polysomnography. MAIN OUTCOME MEASUREMENTS: Patients who snored during CS in the left lateral decubitus position for 10 seconds or longer were referred for polysomnography. Sex- and BMI-matched patients who did not snore served as control subjects. RESULTS: A total of 131 patients were enrolled, and 24 (18.3%) of them snored. These patients (22 men, 2 women) had a predominance of Mallampati grade III/IV, higher Stanford and Epworth scale scores, and greater BMI and neck circumference and were more likely to report daytime sleepiness, decreased vigilance, and personality and mood changes (all P values <.05). All investigated patients who snored during CS had evidence of OSA versus 4 of 18 control subjects (mean apnea-hypopnea index: 40 events vs 5 events; P < .0001) (100% positive predictive value; 77.8% negative predictive value). Moderate or severe OSA was detected in 14 of 20 patients versus 1 of 18 control subjects (P < .001; 70% positive predictive value; 94.4% negative predictive value, 93% sensitivity, 74% specificity). Data obtained from sleep questionnaires and physical examination failed to accurately predict OSA. LIMITATIONS: Single-center nature and relatively small number of patients developing the outcome variable. CONCLUSIONS: Snoring during CS is a strong predictor of OSA. Given the medical and financial burden of undiagnosed OSA, these patients should be carefully identified and referred for sleep medication evaluation.

Metabolic and respiratory variables during pressure support versus synchronized intermittent mandatory ventilation.

BACKGROUND: Mechanically ventilated patients interact and respond differently to different modes of ventilatory support. OBJECTIVES: To assess changes in metabolic and respiratory variables during equivalent changes with either pressure support ventilation (PSV) or volume-cycled synchronized intermittent mandatory ventilation (SIMV) in non-tracheostomized patients without known obstructive pulmonary disease receiving short-term mechanical ventilation in the intensive care unit. METHODS: Fourteen patients receiving volume-cycled SIMV at 12 breaths/min (SIMV(100%)) were included in the study. The PSV level (PSV(100%)) resulting in a minute volume and respiratory rate equivalent to that during SIMV(100%) was determined for each patient. Then each patient underwent trials at 66% and 33% of initial ventilator support with volume-cycled SIMV (SIMV(66%) and SIMV(33%)) and PSV (PSV(66%) and PSV(33%)) in random order. At the end of each trial, oxygen consumption ((.)VO2), carbon dioxide production ((.)VCO2), measured energy expenditures (MEE), peak inspiratory flow, total respiratory frequency, tidal volume, minute ventilation, occlusion pressure (P(0.1)) and inspiratory duty cycle (T(i)/T(tot)) were measured. RESULTS: There were smaller changes in (.)VO2, (.)VCO2 and MEE when equivalent changes were applied with PSV (15.7 +/- 4.4; 12.5 +/- 2.2 and 15 +/- 3.5%) compared with volume-cycled SIMV (32.7 +/- 7.7; 23 +/- 5.2 and 30.7 +/- 6.8%; p < 0.05). P(0.1) and T(i)/T(tot) were significantly smaller during PSV (2.64 +/- 0.28 and 0.38 +/- 0.03 cm H(2)O) than volume-cycled SIMV (4.01 +/- 0.21 and 0.43 +/- 0.02 cm H2O; p < 0.05). CONCLUSIONS: Changes in the level of PSV resulted in smaller changes in metabolic and respiratory variables compared with equivalent changes in the level of volume-cycled SIMV support. PSV may be more suitable for progressive respiratory muscle reloading.

Primary dedifferentiated chondrosarcoma of the lung.

Extraskeletal dedifferentiated chondrosarcomas (DC) are uncommon tumors that predominantly occur in the head and neck. Herein, we describe a case of pulmonary DC detected in a patient with systemic sclerosis and presenting with a symptomatic large pleural effusion and a pulmonary lobar consolidation on chest imaging. To the best of our knowledge, this is the first report of pulmonary chondrosarcoma involving the pleura and occurring in association with systemic sclerosis. Moreover, this is the second report of a dedifferentiated variant among all reported cases of primary lung chondrosarcoma.

Prophylactic amiodarone versus lidocaine for prevention of reperfusion ventricular fibrillation after release of aortic cross-clamp.

BACKGROUND AND OBJECTIVE: Ventricular fibrillation is common after aortic cross-clamp release in patients undergoing open-heart surgeries. The aim of the study was to evaluate the efficacy of the prophylactic administration of 150 mg amiodarone by way of the pump 2 min before release of aortic cross-clamp in preventing ventricular fibrillation. METHODS: The present study is a prospective, randomized, controlled and blinded study performed at a teaching university hospital where 120 patients undergoing coronary bypass graft surgery were randomly assigned to three groups. Each group received either 150 mg of amiodarone or 100 mg lidocaine or isotonic saline by way of pump 2 min before release of the aortic cross-clamp. The frequency of occurrence of ventricular fibrillation and the subsequent required defibrillation counter shocks were determined in all groups. RESULTS: The frequency of occurrence of ventricular fibrillation was significantly higher in both the amiodarone (48%) and the control group (45%) as compared with the lidocaine group (20%) with no statistically significant difference between the amiodarone and the control groups. Furthermore, when ventricular fibrillation occurred, the percentage of patients requiring defibrillation counter shocks was significantly higher in both the amiodarone (58%) and control (61%) groups as compared with the lidocaine group (13%) with no difference between the amiodarone and the control groups, despite a significant decrease in the defibrillation counter shocks energy requirements in the amiodarone group. CONCLUSION: The present study showed no difference between amiodarone (150 mg) and placebo in preventing ventricular fibrillation after release of aortic cross-clamp. In addition, the use of lidocaine was able to reduce the incidence of ventricular fibrillation as compared with both amiodarone and placebo.

Clinical review: liberation from mechanical ventilation.

Mechanical ventilation is the defining event of intensive care unit (ICU) management. Although it is a life saving intervention in patients with acute respiratory failure and other disease entities, a major goal of critical care clinicians should be to liberate patients from mechanical ventilation as early as possible to avoid the multitude of complications and risks associated with prolonged unnecessary mechanical ventilation, including ventilator induced lung injury, ventilator associated pneumonia, increased length of ICU and hospital stay, and increased cost of care delivery. This review highlights the recent developments in assessing and testing for readiness of liberation from mechanical ventilation, the etiology of weaning failure, the value of weaning protocols, and a simple practical approach for liberation from mechanical ventilation.

Metastases in malignant pleural mesothelioma: a new radiological appearance.

This report describes a patient with malignant pleural mesothelioma who presented with a right-sided pleural effusion and contralateral parenchymal metastases manifesting as alveolar opacities with air bronchograms. This radiological pattern of metastases has never been described before. The patient died from respiratory failure related to extensive parenchymal metastases, an outcome seldom reported with malignant pleural mesothelioma.

Cost-utility of non-invasive mechanical ventilation: Analysis and implications in acute respiratory failure. A brief narrative review.

The growing interest in the quality of patient care at the levels of the health care managers, insurance companies, and health professionals is evident. Further, the growing population requires good quality health services. In this review, we analyzed the cost-effectiveness of noninvasive ventilation (NIV) in an acute setting for the treatment of respiratory failure. The strength of this review is that it identified and summarized the most relevant studies regarding various aspects of the cost-utility of NIV in an acute setting. This is the first review that focuses on the importance of the skills and training of the team in the reduction of costs associated with NIV. However, the small number of studies, heterogeneity of quality, and different outcomes of the different studies are the greatest limitations of this review. In conclusion, although there is great variation in the data drawn from the literature, NIV seems to be a cost-effective tool, especially in specific patients (those with chronic obstructive pulmonary disease) for whom the addition of NIV improves outcomes and has a positive impact on this expenditure.

Evaluation of nutrition support practices: Results from a nationwide survey.

BACKGROUND: Multiple clinical guidelines are available to improve and standardize the delivery of nutrition support. However, recommendations are not being universally applied at the bedside due to challenges of resources and barriers of knowledge. Assessing the current level of nutrition support practice is the first step to understand the barriers and ultimately implement potential strategies to increase guideline adherence and promote quality nutrition support in hospitals. There are no published data concerning the practice of nutrition support in Lebanese hospitals. OBJECTIVES: The objective of our study is to investigate for the first time the current clinical practice pertinent to nutrition support across Lebanon. METHODS: A survey was developed by The Nutrition Board of the Lebanese Society of Critical Care Medicine (LSCCM) to determine nutrition support practices in hospitals with an Intensive Care Unit (ICU) across Lebanon. The 28-question survey assesses the delivery of feeding methods such as oral nutrition supplements (ONS), enteral nutrition (EN), and parenteral nutrition (PN). RESULTS: Fourty-one hospitals from 116 total completed the survey. The majority of the hospitals (92.6%) do not systematically use a screening system for malnutrition. Seventy six percent of hospitals reported less than 5% of their patients are kept for more than 7 days with no nutrition support. Early EN is used in preference over PN in ICUs, as 72% of hospitals start early EN (within 48 h) in more than 10% of cases while only 30% of hospitals start early PN (within the first week) in more than 10% of cases. Fifty-one percent of the hospitals use ready prepared formula while the rest (49%) use kitchen prepared formula. CONCLUSIONS: Our study is the first of its kind in Lebanon aiming at describing the current clinical practice in nutrition support at a national level. Working toward the use of a nutritional screening tool on admission and the exclusive use of ready made formula for enteral feeding will have the most significant and immediate impact on improving quality of nutritional care for hospitalized patients. This can be achieved mainly through the education of the concerned staff.

Emergence of Mycobacterium simiae: A retrospective study from a tertiary care center in Lebanon.

OBJECTIVE: The objective of this study is to describe the clinical significance of Mycobacterium simiae at a major tertiary care center in Lebanon. METHODS: This is a retrospective study of patients with positive cultures for M. simiae isolated between 2004 and 2016 at the American University of Beirut Medical Center. RESULTS: This study included 103 M. simiae isolates recovered from 51 patients. Their mean age was 62.7 years. The majority were males and smokers. Specimens were mostly from respiratory sources (97%). Common comorbidities included chronic lung disease (such as chronic obstructive pulmonary disease), solid tumor, systemic disease, and diabetes mellitus. Productive cough and dyspnea were the most common symptoms. Frequent radiographic findings were infiltrates and nodules on chest X-ray and nodules, infiltrates, and bronchiectasis on chest computed tomography scan. Among 18 tested isolates, 5.8% were resistant to clarithromycin, 11.7% to amikacin, and 70-100% to other antimicrobials. Out of 13 patients receiving early treatment, 5 noted improvement, one had recurrence of symptoms, two received alternative diagnosis, and five died. Two of those deaths were related to M. simiae. Common treatment regimens included clarithromycin in different combinations with trimethoprim-sulfamethoxazole, moxifloxacin, and amikacin. Moreover, clofazimine was used in only two patients whose isolates were resistant to all but one agent. Duration of treatment ranged from 6-24 months. CONCLUSION: In Lebanon, M. simiae is increasingly encountered with true infection rates of at least 47%. Furthermore, the prevalence of multidrug resistance among the Lebanese M. simiae isolates is very high limiting the treatment options.

Use of heparinized versus non-heparinized syringes for measurements of the pleural fluid pH.

BACKGROUND: Pleural fluid (PF) pH measurement is important for establishing a diagnosis and for guiding clinical management. The current standard practice is to collect PF samples for pH measurement in heparinized syringes at room temperature and to instantaneously process these samples. OBJECTIVE: The purpose of this study is to investigate the effect of collecting PF in heparinized versus non-heparinized syringes at room temperature on PF pH measurements when processed at various time intervals. METHODS: From 50 consecutive thoracenteses, 1 ml of PF was collected anaerobically in each of six 3-ml syringes. Only three syringes were coated with heparin. The samples were processed for PF pH measurements at time 0 (T(0)) and 1 h (T(1)) and 2 h (T(2)) after collection. All specimens were preserved at room temperature, until the measurements were carried out in duplicates by a calibrated blood gas analyzer. RESULTS: PF pH values were significantly lower with heparinized versus non-heparinized syringes at all time intervals (T(0): pH heparinized = 7.378 +/- 0.107 vs. pH non-heparinized = 7.390 +/- 0.108; T(1): pH heparinized = 7.378 +/- 0.115 vs. pH non-heparinized = 7.389 +/- 0.111; T(2): pH heparinized = 7.367 +/- 0.105 vs. pH non-heparinized = 7.389 +/- 0.121). In the heparinized syringes, there was a significant decrease in PF pH values at T(2) versus T(0) and T(1). There were no significant changes in PF pH values over time in the non-heparinized syringes. CONCLUSIONS: For serial PF pH measurements, the same type of syringes (either heparinized or non-heparinized) should be consistently used. With heparinized syringes, processing of PF pH measurements should be performed within 1 h after collection.