Diltiazem Does Not Prevent Postoperative Atrial Fibrillation After Thoracoscopic Lobectomy

OBJECTIVE

Thoracoscopic lobectomy is associated with lower rates of adverse events compared to thoracotomy. Despite this, postoperative atrial fibrillation (POAF) occurs in at least 10% of patients. Our objective is to determine if prophylaxis with diltiazem significantly reduced POAF events.

METHODS

Patients without prior history of atrial fibrillation who underwent thoracoscopic lobectomy from 2007 to 2016 at one institution were analyzed in a retrospective cohort study utilizing a prospective database. Patients treated from 2007 to 2012 received no prophylaxis. Patients treated after 2012 received diltiazem postoperatively. All patients were monitored with continuous telemetry postoperatively. Multivariate direct logistic regression was performed to determine independent predictors of POAF. We report adjusted odds ratios and accompanying 95% confidence intervals, with P < 0.05 denoting statistical significance.

RESULTS

The final regression model included 416 patients (52 with POAF, 364 without). In univariate analysis, the variables of body mass index and history of congestive heart failure, diabetes, or hypertension, and prophylaxis status did not meet inclusion criteria. Age, gender, history of stroke or transient ischemic attack, and vascular disease were included. Only ages 65 to 74 (P = 0.03) and ≥75 (P = 0.02), compared to <65, were statistically significant predictors of POAF. Adjusted odds ratios of ages 65 to 74 and ≥75 were 2.88 and 2.62, respectively.

CONCLUSIONS

Diltiazem prophylaxis did not significantly reduce POAF incidence following thoracoscopic lobectomy. Further study is warranted since POAF remains an unwanted source of morbidity and cost for lobectomy patients.

Inappropriate preinjury warfarin use in trauma patients: A call for a safety initiative

Introduction:

Warfarin continues to be widely prescribed for a variety of conditions. It has been shown that preinjury warfarin may worsen outcomes in trauma patients. We hypothesized that a substantial proportion of injured patients seen at our institution were receiving preinjury warfarin for inappropriate indications and that a significant number of such patients had subtherapeutic or supratherapeutic international normalized ratios as well as increased mortality.

Materials and Methods:

A retrospective review of registry data from a Level I trauma center was conducted for the period from January 2004 to July 2013. Included were patients aged ≥22 years (based on the youngest recorded patient on warfarin in this study). Abstracted variables included patient age, Injury Severity Score (ISS), Maximum Abbreviated Injury Score for Head (MAISH), mortality, hospital length of stay (HLOS), indication(s) for anticoagulant therapy, admission Glasgow Coma Scale (GCS), and admission international normalized ratio (INR). Suitability of warfarin indication(s) was determined using the most recent American College of Chest Physicians (ACCP) Guidelines. Inappropriate warfarin administration was defined as use inconsistent with these guidelines. For outcome comparisons, a case-control design with 1:1 ratio was used, matching patients taking preinjury warfarin to a random sample of trauma patients who were not taking warfarin. Severe traumatic brain injury (sTBI) was defined as MAISH ≥4.

Results:

A total of 700 out of 14,583 patients aged ≥22 years were receiving preinjury warfarin (4.8% incidence, WG). This group was age- and ISS-matched with 700 patients (4.8% total sample) who were not taking warfarin (NWG) in a total case-control sample of 1,400. The two groups were similar in age, gender, ISS, and initial GCS. According to the ACCP guidelines, 115/700 (16.4%) patients in the warfarin group were receiving anticoagulation for inappropriate indications. Nearly 65% of the patients were outside of their intended INR therapeutic window (43.4% subtherapeutic, 21.6% supratherapeutic). Overall, median HLOS was greater among patients taking preinjury warfarin (4 days vs 2 days, P < 0.010). Mortality was higher in the WG (7.4% or 52/700) than in the NWG (1.9% or 13/700, P < 0.010). Patients with sTBI in the WG had significantly greater mortality (12.8% or 34/266) than those with sTBI in the NWG (5.3% or 9/169, P < 0.013).

Conclusion:

A significant proportion of trauma patients admitted to our institution were noted to take warfarin for inappropriate indications. Moreover, many patients taking warfarin had either subtherapeutic or supratherapeutic INR. Although warfarin use did not independently predict mortality, preinjury warfarin use was associated with greater mortality and HLOS in the subset of patients with sTBI. Safety initiatives directed at better initiation and management of warfarin are needed.

Comorbidity-Polypharmacy Score as Predictor of Outcomes in Older Trauma Patients: A Retrospective Validation Study

INTRODUCTION

Traditional injury severity assessment is insufficient in estimating the morbidity and mortality risk for older (≥45 years) trauma patients. Commonly used tools involve complex calculations or tables, do not consider all comorbidities, and often rely on data that are not available early in the trauma patient's hospitalization. The comorbidity-polypharmacy score (CPS), a sum of all pre-injury medications and comorbidities, was found in previous studies to independently predict morbidity and mortality in this older patient population. However, these studies are limited by relatively small sample sizes. Consequently, we sought to validate previous research findings in a large, administrative dataset.

METHODS

A retrospective study of patients ages≥45 years was performed using an administrative trauma database from St. Luke's University Hospital's Level I Trauma Center. The study period was from 1 January 2008 to 31 December 2013. Abstracted data included patient demographics, injury mechanism and severity [injury characteristics and severity score (ISS)], Glasgow coma scale (GCS), hospital and intensive care unit lengths of stay (HLOS and ILOS, respectively), morbidity, post-discharge destination, and in-hospital mortality. Univariate analyses were conducted with mortality, all-cause morbidity, and discharge destination as primary end-points. Variables reaching statistical significance (p≤0.20) were included in a multivariate logistic regression model. Data are presented as adjusted odds ratios (AORs), with p<0.05 denoting statistical significance.

RESULTS

A total of 5863 patient records were analyzed. Average patient age was 68.5±15.3 years (52% male, 89% blunt mechanism, mean GCS 14.3). Mean HLOS and ILOS increased significantly with increasing CPS (p<0.01). Independent predictors of mortality included age (AOR 1.05, p<0.01), CPS (per-unit AOR 1.08, p<0.02), GCS (AOR 1.43 per-unit decrease, p<0.01), and ISS (per-unit 1.08, p<0.01). Independent predictors of all-cause morbidity included age (AOR 1.02, p<0.01), GCS (AOR per-unit decrease 1.08, p<0.01), ISS (per-unit AOR 1.09, p<0.01), and CPS (per-unit AOR 1.04, p<0.01). CPS did not independently predict need for discharge to a facility.

CONCLUSIONS

This study confirms that CPS is an independent predictor of all-cause morbidity and mortality in older trauma patients. However, CPS was not independently associated with need for discharge to a facility. Prospective multicenter studies are needed to evaluate the use of CPS as a predictive and interventional tool, with special focus on correlations between specific pre-existing conditions, pharmacologic interactions, and morbidity/mortality patterns.

Dynamic behavior of venous collapsibility and central venous pressure during standardized crystalloid bolus: A prospective, observational, pilot study

INTRODUCTION

Measurement of intravascular volume status is an ongoing challenge for physicians in the surgical intensive care unit (SICU). Most surrogates for volume status, including central venous pressure (CVP) and pulmonary artery wedge pressure, require invasive lines associated with a number of potential complications. Sonographic assessment of the collapsibility of the inferior vena cava (IVC) has been described as a noninvasive method for determining volume status. The purpose of this study was to analyze the dynamic response in IVC collapsibility index (IVC-CI) to changes in CVP in SICU patients receiving fluid boluses for volume resuscitation.

MATERIALS AND METHODS

A prospective pilot study was conducted on a sample of SICU patients who met clinical indications for intravenous (IV) fluid bolus and who had preexisting central venous access. Boluses were standardized to crystalloid administration of either 500 mL over 30 min or 1,000 mL over 60 min, as clinically indicated. Concurrent measurements of venous CI (VCI) and CVP were conducted right before initiation of IV bolus (i.e. time 0) and then at 30 and 60 min (as applicable) after bolus initiation. Patient demographics, ventilatory parameters, and vital sign assessments were recorded, with descriptive outcomes reported due to the limited sample size.

RESULTS

Twenty patients received a total of 24 IV fluid boluses. There were five recorded 500 mL boluses given over 30 min and 19 recorded 1,000 mL boluses given over 60 min. Mean (median) CVP measured at 0, 30, and 60 minutes post-bolus were 6.04 ± 3.32 (6.5), 9.00 ± 3.41 (8.0), and 11.1 ± 3.91 (12.0) mmHg, respectively. Mean (median) IVC-CI values at 0, 30, and 60 min were 44.4 ± 25.2 (36.5), 26.5 ± 22.8 (15.6), and 25.2 ± 21.2 (14.8), respectively.

CONCLUSIONS

Observable changes in both VCI and CVP are apparent during an infusion of a standardized fluid bolus. Dynamic changes in VCI as a measurement of responsiveness to fluid bolus are inversely related to changes seen in CVP. Moreover, an IV bolus tends to produce an early response in VCI, while the CVP response is more gradual. Given the noninvasive nature of the measurement technique, VCI shows promise as a method of dynamically measuring patient response to fluid resuscitation. Further studies with larger sample sizes are warranted.

Academic College of Emergency Experts in India's INDO-US Joint Working Group and OPUS12 Foundation Consensus Statement on Creating A Coordinated, Multi-Disciplinary, Patient-Centered, Global Point-of-Care Biomarker Discovery Network

Biomarker science brings great promise to clinical medicine. This is especially true in the era of technology miniaturization, rapid dissemination of knowledge, and point-of-care (POC) implementation of novel diagnostics. Despite this tremendous progress, the journey from a candidate biomarker to a scientifically validated biomarker continues to be an arduous one. In addition to substantial financial resources, biomarker research requires considerable expertise and a multidisciplinary approach. Investigational designs must also be taken into account, with the randomized controlled trial remaining the “gold standard”. The authors present a condensed overview of biomarker science and associated investigational methods, followed by specific examples from clinical areas where biomarker development and/or implementation resulted in tangible enhancements in patient care. This manuscript also serves as a call to arms for the establishment of a truly global, well-coordinated infrastructure dedicated to biomarker research and development, with focus on delivery of the latest discoveries directly to the patient via point-of-care technology.

Volitional pursed lips breathing in patients with stable chronic obstructive pulmonary disease improves exercise capacity

Pursed lips breathing (PLB) is used by a proportion of patients with chronic obstructive pulmonary disease (COPD) to alleviate dyspnea. It is also commonly used in pulmonary rehabilitation. Data to support its use in patients who do not spontaneously adopt PLB are limited. We performed this study to assess the acute effects of PLB on exercise capacity in nonspontaneously PLB patients with stable COPD. We performed a randomized crossover study comparing 6-min walk test (6MWT) at baseline without PLB with 6WMT using volitional PLB. Spirometry, maximal inspiratory and expiratory mouth pressures, and diaphragmatic excursion during tidal and vital capacity breathing using B-mode ultrasonography were measured at baseline and after 10 min of PLB. A Visual Analog Scale (VAS) assessed subjective breathlessness at rest, after 6MWT and after 6MWT with PLB. p ≤ 0.01 was considered significant. Mean ± SD age of patients was 53.1 ± 7.4 years. Forced expiratory volume in 1 second was 1.1 ± 0.4 L/min (38.4 ± 13.2% predicted). Compared with spontaneous breathing, all but one patient with PLB showed a significant increment in 6MW distance (+34.9 ± 26.4 m; p = 0.002). There was a significant reduction in respiratory rate post 6MWT with PLB compared with spontaneous breathing (-4.4 ± 2.8 per minute; p = 0.003). There was no difference in VAS scores. There was a significant correlation between improvement in 6MWT distance and increase in diaphragmatic excursion during forced breathing. The improvement was greater in patients who had poorer baseline exercise performance. PLB has an acute benefit on exercise capacity. Sustained PLB or short bursts of PLB may improve exercise capacity in stable COPD.

Logistic regression: a brief primer

Regression techniques are versatile in their application to medical research because they can measure associations, predict outcomes, and control for confounding variable effects. As one such technique, logistic regression is an efficient and powerful way to analyze the effect of a group of independent variables on a binary outcome by quantifying each independent variable's unique contribution. Using components of linear regression reflected in the logit scale, logistic regression iteratively identifies the strongest linear combination of variables with the greatest probability of detecting the observed outcome. Important considerations when conducting logistic regression include selecting independent variables, ensuring that relevant assumptions are met, and choosing an appropriate model building strategy. For independent variable selection, one should be guided by such factors as accepted theory, previous empirical investigations, clinical considerations, and univariate statistical analyses, with acknowledgement of potential confounding variables that should be accounted for. Basic assumptions that must be met for logistic regression include independence of errors, linearity in the logit for continuous variables, absence of multicollinearity, and lack of strongly influential outliers. Additionally, there should be an adequate number of events per independent variable to avoid an overfit model, with commonly recommended minimum "rules of thumb" ranging from 10 to 20 events per covariate. Regarding model building strategies, the three general types are direct/standard, sequential/hierarchical, and stepwise/statistical, with each having a different emphasis and purpose. Before reaching definitive conclusions from the results of any of these methods, one should formally quantify the model's internal validity (i.e., replicability within the same data set) and external validity (i.e., generalizability beyond the current sample). The resulting logistic regression model's overall fit to the sample data is assessed using various goodness-of-fit measures, with better fit characterized by a smaller difference between observed and model-predicted values. Use of diagnostic statistics is also recommended to further assess the adequacy of the model. Finally, results for independent variables are typically reported as odds ratios (ORs) with 95% confidence intervals (CIs).

Knowledge, attitudes, and practice behaviors of oncology advanced practice nurses regarding advanced care planning for patients with cancer

PURPOSE/OBJECTIVES

To establish initial reliability and validity of a Web-based survey focused on oncology advanced practice nurses' (APNs') knowledge, attitudes, and practice behaviors regarding advanced care planning, and to obtain preliminary understanding of APNs' knowledge, attitudes, and practice behaviors and perceived barriers to advanced care planning.

DESIGN

Descriptive, cross-sectional, pilot survey study.

SETTING

The eastern United States.

SAMPLE

300 oncology APNs.

METHODS

Guided by the Theory of Planned Behavior, a knowledge, attitudes, and practice behaviors survey was developed and reviewed for content validity. The survey was distributed to 300 APNs via e-mail and sent again to the 89 APNs who responded to the initial survey. Exploratory factor analysis was used to examine the construct validity and test-retest reliability of the survey's attitudinal and practice behavior portions.

MAIN RESEARCH VARIABLES

Respondents' demographics, knowledge, attitudes, practice behaviors, and perceived barriers to advanced care planning practice.

FINDINGS

Exploratory factor analysis yielded a five-factor solution from the survey's attitudes and practice behavior portions with internal consistency using Cronbach alpha. Respondents achieved an average of 67% correct answers in the 12-item knowledge section and scored positively in attitudes toward advanced care planning. Their practice behavior scores were marginally positive. The most common reported barriers were from patients' and families' as well as physicians' reluctance to discuss advanced care planning.

CONCLUSIONS

The attitudinal and practice behaviors portions of the survey demonstrated preliminary construct validity and test-retest reliability. Regarding advanced care planning, respondents were moderately knowledgeable, but their advanced care planning practice was not routine.

IMPLICATIONS FOR NURSING

Validly assessing oncology APNs' knowledge, attitudes, and practice behaviors regarding advanced care planning will enable more tailored approaches to improve end-of-life care outcomes.

Effect of tripod position on objective parameters of respiratory function in stable chronic obstructive pulmonary disease

OBJECTIVE

To examine changes in respiratory dynamics in patients with chronic obstructive pulmonary disease (COPD) sitting leaning forward with hands supported on the knees (tripod position), a posture frequently assumed by patients in respiratory distress.

METHODS

Spirometry, maximal inspiratory and expiratory pressures (MIP and MEP) generated at the mouth, and diaphragmatic excursion during tidal and vital capacity maneuver breathing measured by B-mode ultrasonography were studied in 13 patients with stable COPD in sitting, supine and tripod positions.

RESULTS

Mean +/- SD age of patients was 52.2 +/- 6.8 years. Median disease duration was three years. There was no statistically significant difference in spirometry for sitting, supine and tripod positions (FEV1: 1.11 +/- 0.4L, 1.14 +/- 0.5L and 1.11 +/- 0.4L; p = 0.99), respectively, (FEV1/FVC: 49.2 +/- 11.0, 53.7 +/- 8.5 and 48.5 +/- 11.3, p = 0.37), mouth pressures (MIP: 102.9 +/- 28.9, 90.6 +/- 29.1 and 99.2 +/- 32.9 cm H2O, p = 0.61 and MEP: 100.8 +/- 29.9, 100.4 +/- 34.4 and 90.6 +/- 32.6 cm H2O, p = 0.74) and diaphragmatic movements during tidal (16.1 +/- 5.9, 20.1 +/- 6.8 and 16.6 +/- 6.2 mm, p = 0.22) and forced breathing (33.9 +/- 11.0, 43.1 +/- 19.6 and 37.4 +/- 17.1 mm, p = 0.35).

CONCLUSION

Commonly measured indices of respiratory function were not different in the tripod compared to sitting and supine positions.