Shruti B. Patel

Sedation and Analgesia in the Mechanically Ventilated Patient

Sedation and analgesia are important components of care for the mechanically ventilated patient in the intensive care unit (ICU). An understanding of commonly used medications is essential to formulate a sedation plan for individual patients. The specific physiological changes that a critically ill patient undergoes can have direct effects on the pharmacology of drugs, potentially leading to interpatient differences in response. Objective assessments of pain, sedation, and agitation have been validated for use in the ICU for assessment and titration of medications. An evidence-based strategy for administering these drugs can lead to improvements in short- and long-term outcomes for patients. In this article, we review advances in the field of ICU sedation to provide an up-to-date perspective on management of the mechanically ventilated ICU patient.

Prevalence of hiatal hernia by blinded multidetector CT in patients with idiopathic pulmonary fibrosis

Hiatal hernia (HH) is associated with gastro-oesophageal reflux (GOR) and/or GOR disease and may contribute to idiopathic pulmonary fibrosis (IPF). We hypothesised that HH evaluated by computed tomography is more common in IPF than in asthma or chronic obstructive pulmonary disease (COPD), and correlates with abnormal GOR measured by pH probe testing. Rates of HH were compared in three cohorts, IPF (n=100), COPD (n=60) and asthma (n=24), and evaluated for inter-observer agreement. In IPF, symptoms and anti-reflux medications were correlated with diffusing capacity of the lung for carbon monoxide (DL,CO) and composite physiologic index (CPI). HH was correlated with pH probe testing in IPF patients (n=14). HH was higher in IPF (39%) than either COPD (13.3%, p=0.00009) or asthma (16.67%, p=0.0139). The HH inter-observer &kgr; agreement was substantial in IPF (&kgr;=0.78) and asthma (&kgr;=0.86), and moderate in COPD (&kgr;=0.42). In IPF, HH did not correlate with lung function, except in those on anti-reflux therapy, who had a better DL,CO (p<0.03) and CPI (p<0.04). HH correlated with GOR as measured by DeMeester scores (p<0.04). HH is more common in IPF than COPD or asthma. In an IPF cohort, HH correlated with higher DeMeester scores, confirming abnormal acid GOR. Presence of HH alone was not associated with decreased lung function.

Impact of Ventilator Adjustment and Sedation–analgesia Practices on Severe Asynchrony in Patients Ventilated in Assist-control Mode*

Objectives:Breath-stacking asynchrony during assist-control-mode ventilation may be associated with increased tidal volume and alveolar pressure that could contribute to ventilator-induced lung injury. Methods to reduce breath stacking have not been well studied. The objective of this investigation was to evaluate 1) which interventions were used by managing clinicians to address severe breath stacking; and 2) how effective these measures were. Setting:Sixteen-bed medical ICU. Patients and Interventions:Physiological study in consecutively admitted patients without severe brain injury, who had severe breath stacking defined as an asynchrony index greater than or equal to 10% of total breaths. During 30 minutes before (baseline) and after any intervention employed by the managing clinician, the ventilator flow, airway pressure, and volume/time waveforms were continuously recorded and analyzed to detect normal and stacked breaths. The initial approach taken was assigned to one of three categories: no intervention, increase of sedation–analgesia, or change of ventilator setting. Nonparametric Wilcoxon-Mann-Whitney tests and multiple regression were used for statistical analysis. Quantitative data are presented as median [25–75]. Main Results:Sixty-six of 254 (26%) mechanically ventilated patients exhibited severe breath-stacking asynchrony. A total of 100 30–minute sequences were recorded and analyzed in 30 patients before and after 50 clinical decisions for ongoing management (no intervention, n = 8; increasing sedation/analgesia, n = 16; ventilator adjustment, n = 26). Breath-stacking asynchrony index was 44 [27–87]% at baseline. Compared with baseline, the decrease of asynchrony index was greater after changing the ventilator setting (−99 [−92, −100]%) than after increasing the sedation–analgesia (−41 [−66, 7]%, p < 0.001) or deciding to tolerate the asynchrony (4 [−4, 12]%, p < 0.001). Pressure-support ventilation and increased inspiratory time were independently associated with the reduction of asynchrony index. Conclusions:Compared with increasing sedation–analgesia, adapting the ventilator to patient breathing effort reduces breath-stacking asynchrony significantly and often dramatically. These results support an algorithm beginning with ventilator adjustment to rationalize the management of severe breath-stacking asynchrony in ICU patients.

Electromagnetic navigational bronchoscopy: an effective and safe approach to diagnose peripheral lung lesions unreachable by conventional bronchoscopy in high-risk patients.

Purpose The purpose of this study was to investigate the diagnostic yield and safety of electromagnetic navigation bronchoscopy (ENB) on peripheral lung lesions deemed otherwise unreachable using conventional bronchoscopy in high-risk patients. Methods This was a retrospective chart review involving adults (age, 18 y and older) who underwent ENB for pulmonary lesions located at the fourth order of bronchi or beyond, including subpleural lesions, at the University of Chicago Medical Center. Forty-eight patients underwent ENB by 3 different trained operators from January 2006 to September 2008. There was a short period of inactivity when the device was withdrawn from the market. ENB was reserved for use only in lesions at the fourth order of bronchi or beyond, including subpleural lesions, in patients who are considered high risk for other invasive procedures. Pathologic, cytologic, and microbiologic studies were carried out on recovered samples. Postprocedural chest radiographs were obtained on all patients to detect the presence of procedure-associated complications. Results ENB led to the diagnosis of 37 of 48 (77%) lesions not amenable to conventional bronchoscopic biopsy in high-risk patients. Of the 37 successful procedures, malignancy was identified in 18 patients (49%). Nonsmall cell lung cancer (NSCLC) was diagnosed 16 times, whereas both small cell lung cancer and carcinoid tumor were diagnosed once. In addition, 4 lesions (11%) were found to be infectious, 1 lesion (3%) was found to be granulomatous (noncaseating), and 1 lesion (3%) was diagnosed as organizing pneumonia. Of the 37 successful diagnoses, 13 lesions (35%) were determined to be nonpathologic, benign lesions. Eleven procedures (22%) were unsuccessful in yielding the correct pathologic diagnosis. Nine of the 11 unsuccessful ENB cases (82%) were found to be malignant, 9 of which were identified as NSCLC. Other than NSCLC, 1 neuroendocrine tumor (9%) and 1 metastatic transitional cell carcinoma of the kidney (9%) were identified by alternative, invasive testing methods. The 2 other lesions unsuccessfully diagnosed by ENB were not malignant. One was determined to be infection (histoplasmosis) and the other was diagnosed as an organizing pneumonia. The most common complication noted by all modalities was pneumothorax. ENB carried a pneumothorax rate of 5 of 49 (10%), 2 of which required chest tube insertion for treatment. In the ENB success group, 4 cases (11%) were complicated by pneumothoraces. In the ENB failure group, 1 case (9%) was complicated by a pneumothorax. Conclusions ENB is an effective and low-risk modality for diagnosing pulmonary lesions that are difficult to reach in patients deemed to be at high risk for invasive procedures. Although no clear criteria for the use of ENB currently exist, our study shows that diagnostic sampling can be obtained in 77% of lesions at the fourth order of bronchi or beyond, including subpleural lesions. Clinical Implications ENB is an effective, minimally invasive method for the diagnosis of pulmonary nodules previously deemed unreachable by conventional bronchoscopy in high-risk patients and harbors a low complication rate.

Intrabronchial valves: a case series describing a minimally invasive approach to bronchopleural fistulas in medical intensive care unit patients.

Background:Bronchopleural fistulas (BPF) are conditions associated with prolonged hospital course, high morbidity, and possibly increased mortality. The presence of BPFs in critically ill patients may cause difficulty in ventilation and increased oxygen requirements. Intrabronchial valves (Spiration IBV) serve as a noninvasive therapeutic option for the closure of BPFs. Methods:This report is a retrospective description of 3 patients transferred to our medical intensive care unit (ICU) with BPFs and persistent air leaks (PAL). One patient required high levels of oxygen supplementation through a nonrebreather face mask, whereas 2 required mechanical ventilation because of respiratory failure. IBVs were placed in each patient with the intention of closing their BPF and weaning them from respiratory support. Results:The use of IBVs in ICU patients with BPFs and PALs resulted in 1 patient being weaned from the persistent need for a nonrebreather face mask to room air and also aided in the liberation from mechanical ventilation of 2 patients who had been failing spontaneous breathing trials. Conclusions:The use of IBVs is safe and well tolerated in ICU patients with BPFs and PALs. The placement of IBVs results in significant clinical improvement, allowing for either weaning from high levels of oxygen support or liberation from mechanical ventilation.

Thyroid Disease Is Prevalent and Predicts Survival in Patients With Idiopathic Pulmonary Fibrosis

BACKGROUND A significant minority of patients with idiopathic pulmonary fibrosis (IPF) display features of autoimmunity without meeting the criteria for overt connective tissue disease. A link between IPF and other immune-mediated processes, such as hypothyroidism (HT), has not been reported. In this investigation, we aimed to determine whether HT is associated with IPF and if outcomes differ between patients with IPF with and without HT. METHODS A retrospective case-control analysis was conducted. Of 311 patients referred to the University of Chicago Interstitial Lung Disease Center with an initial diagnosis of IPF, 196 met the inclusion criteria and were included in the final analysis. Each case was matched 1:1 by age, sex, and race to a control subject with COPD. RESULTS HT was identified in 16.8% of cases and 7.1% of control subjects (OR, 2.7; 95% CI, 1.31-5.54; P = .01). Among patients with IPF, HT was associated with reduced survival time (P < .001) and was found to be an independent predictor of mortality in multivariable Cox regression analysis (hazard ratio, 2.12; 95% CI, 1.31-3.43; P = .002). A secondary analysis of two IPF clinical trial datasets supports these findings. CONCLUSIONS HT is common among patients with IPF, with a higher prevalence than in those with COPD and the general population. The presence of HT also predicts mortality in IPF, a finding that may improve future prognostication models. More research is needed to determine the biologic link between IPF and HT and how the presence of thyroid disease may influence disease progression.

Early Tracheotomy After Cardiac Surgery: Not Ready for Prime Time

In this issue, Trouillet and colleagues report a randomized trial of early versus late tracheotomy in patients requiring mechanical ventilation 4 days after cardiac surgery that showed improvements...