May 2013 Pulmonary Journal Club

Shah PL, Zoumot Z, Singh S, Bicknell SR, Ross ET, Quiring J, Hopkinson NS, Kemp SV for the RESET trial Study Group. endobronchial coils for the treatment of severe emphysema with hyperinflation (RESET): a randomised controlled trial. Lancet Respiratory Medicine. 2013;1(3):233-40. Abstract 

Despite advances in pharmacologic therapies, chronic obstructive pulmonary disease (COPD) remains a challenging respiratory disease. It is currently the third leading cause of death. Prior invasive treatment strategies such as endobronchial valves and surgical lung volume reduction have had limited success. Surgical lung volume reduction remains an option in patients with heterogeneous upper lobe predominant emphysema, poor exercise tolerance and FEV1 < 35% (1). The placement of endobronchial coils has been studied in smaller cohort studies and shown to reduce hyperinflation. This study is a larger randomized control trial looking at the efficacy and safety of endobronchial lung volume reduction coils (LRVC).

The study was performed between January 2010 and October 2011 among 3 centers in the United Kingdom. Inclusion criteria included patients with FEV1 < 45%. A total of 47 patients were included in the study. Twenty-four patients were randomized to receive standard medical therapy for COPD and 23 patients were randomized to LRVC. The characteristics of the patients were similar; however there were more men in the medical treatment arm, while the LRVC arm had patients with more severe baseline disease.

The procedure was not blinded. Patients undergoing LRVC received a total of 2 sessions 14 days apart. Procedures were done bronchoscopically under moderate conscious sedation or anesthesia. The procedure entailed deploying an endobronchial coil under fluoroscopic guidance 35mm away from pleural surface. Outcomes were measured at 90 days. The primary outcome was an improvement in quality of life as measured by The St. George’s Respiratory Questionnaire. Secondary outcomes looked at response of FEV1, residual volume and 6 minute walk test. 

In this study the results showed an improvement in quality of life, as well and an increase in 6 minute walk test by 51 meters within the LRVC group when compared to the medical therapy group. There were also improvements in FEV1 and a reduction in residual volume with in the LRVC arm. Side effects within the LRVC included 2 pneumothorax episodes but no fatalities.

Findings from this study look promising but there were several imitations. The study was funded by PneumRx which makes the coils being studied. The lack of blinding, no reported smoking status, and no standardized medications within the medical treatment arm further limit the study. Additional larger trials with long term follow up are needed to further validate this new treatment modality.

Manoj Mathew, MD FCCP MCC

Reference

1. Meyers BF, Patterson GA. Chronic obstructive pulmonary disease: bullectomy, lung volume reduction surgery, and transplantation for patients with chronic obstructive pulmonary disease. Thorax. 2003;58:634-8. doi:10.1136/thorax.58.7.634

Reference as: Mathew M. May 2013 pulmonary journal club. Southwest J Pulm Crit Care. 2013;6(5):243-4. PDF

March 2013 Pulmonary Journal Club

Reignier J, Mercier E, Le Gouge A, Boulain T, Desachy A, Bellec F, Clavel M, Frat JP, Plantefeve G, Quenot JP, Lascarrou JB; Clinical Research in Intensive Care and Sepsis (CRICS) Group. Effect of not monitoring residual gastric volume on risk of ventilator-associated pneumonia in adults receiving mechanical ventilation and early enteral feeding: a randomized controlled trial. JAMA. 2013;309(3):249-56. Full Text

The March pulmonary journal club reviewed the article looking at the effect of gastric residual volume and ventilator associated pneumonia. Most of us would agree that enteral nutrition in the critically ill patient is important but how early and how much is still debatable. In many institutions gastric residual volumes are used to assess gastric motility and help guide rate and cessation of enteral nutrition. This study evaluated the effect of not monitoring gastric residual volume and its effect on ventilator associated pneumonia.

The study was a randomized multicenter non- inferiority trial done in France between 2010-2011. All patients older than 18 years of age and on mechanical ventilation > 48 hours were included.  452 patients were included in the study and randomized into 2 groups. The control group (222 patients) underwent monitoring of gastric residuals every 6 hours while the study group (230 patients) had no monitoring of gastric residuals.  Gastric residual volumes of > 250ml and/or emesis resulted in alteration of enteral feeding rates in the control arm. The primary outcome was the incidence of ventilator associated pneumonia (VAP).

The results demonstrated higher incidences of emesis in the study arm verses the control arm, 40% vs. 27%. Despite this there were no significant differences in the incidence of VAP, 16.7% in study group vs. 15.8% in the control group. There were no differences in mortality or length of days on the ventilator. This study shows that scheduled monitoring of gastric residuals does not decrease incidence of VAP, and should not be instituted as standard practice.

Manoj Mathew, MD  FCCP MCCM

Reference as: Mathew M. March 2013 pulmonary journal club. Southwest J Pulm Crit Care. 2013;6(3):149. PDF

February 2013 Pulmonary Journal Club

Effect of pressure support vs unassisted breathing through a tracheostomy collar on weaning duration in patients requiring prolonged mechanical ventilation: a randomized trial. Jubran A, Grant BJ, Duffner LA, Collins EG, Lanuza DM, Hoffman LA, Tobin MJ. JAMA. 2013;309(7):671-7. Abstract

The rise in prolonged mechanical ventilation has fostered a growth in the need for long term acute care hospitals (LTACH). The February Journal Club reviewed the study looking at ventilator weaning through pressure support trials vs. spontaneous breathing through tracheostomy collar in a LTACH.

The study was a randomized trial performed from 2000 - 2010. It was performed at a single long term acute care facility. Patients that required mechanical ventilation for > 21 days and failed a 5 day screening procedure of spontaneous breathing were included in the study. Included patients were randomized to either a pressure support or tracheostomy collar arm. 500 patients were screened, and a total of 316 patients were included in the study, 155 patients were randomized to pressure support and 161 patients were randomized to tracheostomy collar. The primary outcome was the duration of ventilator weaning. Secondary outcomes were 6 and 12 month mortality.

The results showed that out of the initial 500 screened patients, 160 (32%) were weaned on the initial screening procedure. Among the randomized patients they found that the tracheostomy collar arm had 4 fewer days on the ventilator (15 days vs. 19 days) when compared to the pressure support arm. There were no differences in mortality or adverse outcomes.

The results of this study support prior studies looking at spontaneous breathing trials in the ICU (1). The fact that 32% of patients were weaned on initial screening suggests that we may not be aggressive enough in continuing ventilator weaning trials once the decision to be transferred to LTACH has been made. Several factors such as patient readiness, hemodynamic and lab parameters will continue to influence the method of weaning.  Regardless of what method used, one constant factor that continues to be stressed is that ventilator weaning is not a static process, but rather dynamic, and largely determined by a collaborative effort between physicians and respiratory therapy.

Manoj Mathew, MD FCCP MCCM

Reference

1. Esteban A, Frutos F, Tobin MJ, Alía I, Solsona JF, ValverdúI, Fernández R, de la Cal MA, Benito S, Tomás R, et al. A comparison of four methods of weaning patients from mechanical ventilation. Spanish Lung Failure Collaborative Group. N Engl J Med. 1995;332(6):345-50.

Reference as: Mathew M. February 2013 pulmonary journal club. Southwest J Pulm Crit Care 2013;6(2):90. PDF

January 2013 Pulmonary Journal Club

Kartalija M, Ovrutsky AR, Bryan CL, Pott GB, Fantuzzi G, Thomas J, Strand MJ, Bai X, Ramamoorthy P, Rothman MS, Nagabhushanam V, McDermott M, Levin AR, Frazer-Abel A, Giclas PC, Korner J, Iseman MD, Shapiro L, Chan ED. Patients with nontuberculous mycobacterial lung disease exhibit unique body and immune phenotypes. Am J Respir Crit Care Med. 2013;187(2):197-205. Abstract

Among patients with nontuberculous mycobacterial (NTM) lung disease is a subset of previously healthy women with a slender body morphotype, often with scoliosis and/or pectus excavatum. The authors enrolled 103 patients with NTM and 101 uninfected control subjects of similar demographics. Patients with

NTM had significantly lower body mass index and body fat and were significantly taller than control subjects. Scoliosis, pectus excavatum and gastroesophageal reflux were significantly more prevalent in patients with NTM. The normal relationships between the adipokines and body fat were lost and IFN-g and IL-10 levels were significantly suppressed in stimulated whole blood of patients with NTM.

The description in this article extends the description of the “Lady Windermere syndrome” first described in the early 1990’s by Reich and Johnson (1). They described 6 elderly women who were immunocompetent, had no significant smoking history or underlying pulmonary disease, and developed Mycobacterium avium complex (MAC). They hypothesized that these women could have had the habit of voluntary suppression of cough, responsible for the inability to clear secretions from the lung. However, it is now known that the adiopectins have immunomodulatory functions and the findings suggest that the underlying pathophysiology may be an immune deficit.

Søyseth V, Bhatnagar R, Holmedahl NH, Neukamm A, Høiseth AD, Hagve TA, Einvik G, Omland T. Acute exacerbation of COPD is associated with fourfold elevation of cardiac troponin T. Heart. 2013;99(2):122-6. Abstract

The authors investigated if acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is associated with myocardial injury, expressed as elevated cardiac troponin T (Trop). In a cross-sectional study, Trops in patients hospitalized for AECOPD were compared with COPD patients in their stable state. Mean Trops were elevated in the AECOPD group (25.8 ng/l) compared to the reference group (4.55 ng/l).  Higher Trops were associated with the presence of pathological q-waves (p=0.012) and electrocardiographic left ventricular hypertrophy (p=0.039), long-term oxygen treatment (p=0.002) and decreasing forced expiratory volume in 1 s (p=0.014).

Slight elevations of Trops in patients admitted to the hospital are common, including AECOPD patients. This study suggests that elevated Trops do no necessarily indicate underlying cardiac disease and that cardiac consultation and/or workup is not necessarily indicated in every AECOPD patient with a slight elevation in Trops. Clinical judgment as to whether a cardiac condition coexists with the AECOPD must be used.

Richard A. Robbins, MD

References

1. Reich JM, Johnson RE. Mycobacterium avium complex pulmonary infection presenting as isolated lingular or middle lobe pattern: the lady Windermere Syndrome. Chest 1992;101:1605-9.

Referece as: Robbins RA. January 2013 pulmonary journal club. Southwest J Pulm Crit Care 2013:6(1):41-42. PDF

December 2012 Pulmonary Journal Club

Meddings JA, Reichert H, Rogers MA, Saint S, Stephansky J, McMahon LF.  Effect of nonpayment for hospital acquired catheter associated urinary tract.  Ann Intern Med 2012;157:305-12. Abstract

This observational study compared the rate of catheter associated urinary tract infection (CAUTI) in over 750,000 non-obstetrical adult admissions in 2007, with a comparable number of admissions in 2009 – before and after implementation of Medicare nonpayment for CAUTI.  The study was carried out in 96 nonfederal acute care hospitals in Michigan.  The authors found that although hospitals requested payment for urinary tract infections in over 10% of admissions, they rarely reported CAUTIs (CAUTI reported in 0.09% (95%CI: 0.06-0.12%) of admissions in 2007 vs. 0.14% (95%CI: 0.11-0.17%) in 2009).  Only 2.6% of hospital-acquired UTIs were reported as catheter-associated.  Nonpayment for CAUTI resulted in only 25 of 781,343 admissions in 2009.  Therefore, the new Medicare rule did not decrease the rate of CAUTIs, or generate any significant cost savings.

Previous studies have convincingly demonstrated that urinary tract infections are among the most common hospital-acquired infections.  Epidemiological studies suggest that 59-86% of all hospital-acquired UTIs are catheter-associated – highly contrary to the rate of 2.6% found in this database.  Likewise, extrapolation of previously-published surveillance data indicates that approximately 8,000 CAUTIs would have been expected in a cohort of 780,000 admissions. The finding that nonpayment occurred in only 25 cases strikingly demonstrates the inadvisability of using claims data to identify CAUTI. 

Under current Medicare rules, a hospital coder may only enter a diagnosis of CAUTI if it is clearly identified in a physician (or physician-surrogate) progress note.  No microbiological data are required.  CMS does not require coders to list all hospital-acquired conditions, and since hospitals are facing mounting financial pressure to lower their CAUTI rates, it’s not surprising the rates reported are so low.  It is a little surprising that the rates didn’t decrease under the threat of nonpayment – this may indicate that most hospitals are not actively “gaming the system”, but simply not accurately tracking CAUTI in claims databases, regardless of the threat of financial penalty.  Perversely, current law provides a strong disincentive to local efforts to improve surveillance of CAUTI, since accurate detection would likely increase nonpayment penalties, and could trigger reduction in Medicare payments for all DRGs for an institution that falls into the lowest quartile of hospital performance in 2015.

The diagnosis of CAUTI is often difficult to make with any degree of certainty by a physician at the bedside.  Symptoms of UTI are less specific and sensitive in hospitalized patients – especially those with indwelling Foley catheters.  The clinical diagnosis is largely based on quantitative analysis of pyuria and bacteruria, both of which are highly dependent on urine collection technique.  Until details of bedside diagnosis of CAUTI are formalized, no amount of retrospective chart review by billing coders is likely to provide an accurate tally of CAUTI.

Guideline advocates, researchers and our Federal government ought to quit using billing codes as surrogates for clinical outcomes.  Personally, I believe the best approach to prevent CAUTI will follow from heightened awareness of preventive strategies by bedside clinicians.  As a profession, we are already highly motivated to do what’s best for our patients, even without the questionable benefit of artificial (and sometimes misguided) incentives.

Messerli FH.  Chocolate consumption, cognitive function, and Nobel laureates. New Engl J Med  2012;367:1562-4. Preview

This article describes an epidemiological study that showed a strong correlation between chocolate consumption and per capita Nobel laureates in a comparison of 22 countries.  The correlation coefficient (r=0.79, p<0.0001) indicates that chocolate consumption alone accounts for almost two-thirds of all variation between countries in per capita Nobel laureates.  The authors humorously use this analysis to point out how an inherently weak study design can yield ridiculous results with highly impressive-appearing statistical significance (Sir Austin Bradford Hill would be proud!).   

“Ecological” epidemiological studies such as this are highly susceptible to error because the databases used to derive results contain no information on individual subjects (the basis of the “ecological fallacy”).  Thus, results like those found in this study could occur even if there wasn’t a single Nobel laureate that ever ate chocolate.  A similar study might show that national hot dog consumption was correlated with a powerful Air Force – the two have nothing to do with one-another except that they are both somewhat “American” traits. 

I was tempted to write a letter-to-the-editor in response to this article, referencing a fictional study in which we had found that it was not chocolate consumption, but rather blowing an alphorn while wearing lederhosen, that produced more Nobel laureates.  Biological plausibility is supported by improved cerebral perfusion secondary to increased thoracic bellows strength and augmented preload resulting from compression of lower extremity capacitance veins. 

Robert A. Raschke, MD

Associate Editor

Raschke RA. December 2012 pulmonary journal club. Southwest J Pulm Crit Care 2012;5:306-7. PDF