Use of zonal distribution of lung crackles during inspiration and expiration to assess disease severity in idiopathic pulmonary fibrosis.

PURPOSE OF THE STUDY: To measure the number and distribution of crackles in patients with idiopathic pulmonary fibrosis (IPF) and assess how this relates to measures of disease severity. STUDY DESIGN: Fourteen patients with IPF had both the number of crackles per litre of lung volume and lung function measured every 3 months for 1 year. Crackle counts were expressed according to position (upper and lower zones) and whether they occurred during inspiration and expiration. RESULTS: At baseline, crackle count per unit volume was higher at the bases than the apices and higher during inspiration than during expiration. There was a significant relationship between lung function and number of crackles per unit volume. Upper zone crackles during inspiration (crackle count vs forced vital capacity (FVC): r=0.69, p=0.007) and lower zone crackles during expiration (crackle count vs FVC: r=0.55, p=0.04) demonstrated the strongest relationship with lung function. CONCLUSIONS: Number and distribution of crackles in IPF relate to physiological measures of disease severity. Inspiratory lower zone crackles were universal and extensive but the presence, hence, development of inspiratory upper zone crackles and expiratory lower zone crackles correlated with measures of poorer lung function. The presence or appearance of these assessed using chest auscultation provides a clinician with simple measure of disease severity, and possibly progression, prompting further physiological assessment and review of treatment.

Standards of care for occupational asthma: an update.

BACKGROUND: The British Thoracic Society (BTS) Standards of Care (SoC) Committee produced a standard of care for occupational asthma (OA) in 2008, based on a systematic evidence review performed in 2004 by the British Occupational Health Research Foundation (BOHRF). METHODS: BOHRF updated the evidence base from 2004-2009 in 2010. RESULTS: This article summarises the changes in evidence and is aimed at physicians, nurses and other healthcare professionals in primary and secondary care, occupational health and public health and at employers, workers and their health, safety and other representatives. CONCLUSIONS: Various recommendations and evidence ratings have changed in the management of asthma that may have an occupational cause.

The role of Abrams percutaneous pleural biopsy in the investigation of exudative pleural effusions.

INTRODUCTION: Blind percutaneous pleural biopsy has traditionally been performed to investigate the etiology of exudative pleural effusion in which the initial thoracentesis has been nondiagnostic. In view of the increasing use of image-guided and thoracoscopic pleural biopsies, this study examines the role of blind Abrams pleural biopsy in the investigation of pleural effusion in a large urban hospital. METHOD: Patients undergoing blind Abrams needle biopsy between January 1997 and 2003 were identified from the hospital pathology database. The case notes and pathology records of these patients were analyzed retrospectively. All patients had presented to respiratory teams with an exudative pleural effusion and had initial nondiagnostic thoracentesis. RESULTS: Seventy-five patients undergoing blind biopsy were identified. Pleural tissue was obtained in 59 biopsies (79%), with no statistically significant difference in pleural yield between respiratory specialist registrars (equivalent to pulmonary fellows in training) and senior house officers/preregistration house officers (equivalent to junior residents and interns, respectively) performing the biopsy (chi(2) test, p = 0.43). When up to three samples were obtained per episode, sufficient pleural tissue was obtained in 18 of 25 patients (72%) compared to 80% (32 of 40 patients) in whom four to six samples were taken (chi(2) test, p = 0.55 [not significant]). For all diagnoses, blind biopsy had a sensitivity of 38%, which rose to 43% when reviewing patients in whom sufficient pleural tissue was obtained (for malignant diagnosis alone, sensitivity values were 43% and 51%, respectively; specificity, 100%; negative and positive predictive values, 51%). No fatalities were reported, and pneumothorax was seen in eight patients (11%), with only two patients requiring specific intervention. CONCLUSIONS: Blind Abrams needle biopsy obtaining pleural tissue was diagnostic in approximately 50% of patients presenting with malignant effusion in the sample, and can be performed safely by all grades of medical staff with due attention to technique and supervision. The data support the continued use of the Abrams needle in the investigation of malignant pleural disease.

Breathing patterns associated with trait anxiety and breathlessness in humans.

Idiopathic hyperventilation (IH) is a condition of uncertain aetiology characterized by sustained arterial and alveolar hypocapnia and a plethora of symptoms, the most commonly reported being shortness of breath, and breathlessness. We previously reported that anxiety increases respiratory frequency and minute ventilation with no change in metabolism in normal subjects. In this study, we compared the breathing frequency response to 5% and 7% of CO(2) gas mixtures in normal subjects (n = 13) and in subjects with IH (n = 9), taking into account anxiety and breathlessness in order to determine how breathing patterns may vary with changes in the degree of involvement of higher brain centers because of anxiety and the perception of breathlessness. CO(2) produced a significantly higher value in respiratory frequency (f) in subjects with IH. Subjects with IH also showed lower P(ET)CO(2) than normal subjects. During the inhalation of room air, a significant correlation between f and trait anxiety scores was observed in normal subjects (r = 0.49) and IH subjects (r = 0.69). However, the IH group showed no significantly higher trait anxiety in comparison with normal subjects. There was a significant correlation between the level of perceived breathlessness and f during the inhalation of 5% and 7% CO(2), even during the inhalation of room air in IH subjects. This study suggests that an excessive increase in f in subjects with IH may be due to the interaction of two factors, trait anxiety and breathlessness.

Behavioral influences and physiological indices of ventilatory control in subjects with idiopathic hyperventilation.

Idiopathic hyperventilation has been defined as a respiratory-related psychophysiological complaint. This study attempted to clarify relationships between psychological and physiological variables in this condition. Participants demonstrated increased anxiety, depression, and symptoms consistent with hyperventilation. This was associated with a reduced peripheral chemosensitivity (isocapnic hypoxic rebreathe; -0.84 +/- 0.5 min-1.%O2(-1)), which was normalized with experimentally increased pCO2. Resting CO2 sensitivity was close to normal (2.1 +/- 1.0 min-1.mmHg-1). Breath hold time was significantly reduced versus controls (20.4 s +/- 12 s vs. 63 s +/- 31 s), and resting PETCO2 was correlated with the anxiety score. Also, the ventilatory response to moderate intensity exercise was augmented (vs. controls). The normalcy of pulmonary and chemoreceptor responses suggests that psychological factors may initiate this hyperventilation, which may become a conditioned response with an increased drive to breathe.

Chronic airflow limitation in a rural Indian population: etiology and relationship to body mass index.

PURPOSE: Respiratory conditions remain a source of morbidity globally. As such, this study aimed to explore factors associated with the development of airflow obstruction (AFO) in a rural Indian setting and, using spirometry, study whether underweight is linked to AFO. METHODS: Patients > 35 years old attending a rural clinic in West Bengal, India, took a structured questionnaire, had their body mass index (BMI) measured, and had spirometry performed by an ancillary health care worker. RESULTS: In total, 416 patients completed the study; spirometry was acceptable for analysis of forced expiratory volume in 1 second in 286 cases (69%); 16% were noted to exhibit AFO. Factors associated with AFO were: increasing age (95% confidence interval (CI) 0.004-0.011; P = 0.005), smoking history (95% CI 0.07-0.174; P = 0.006), male gender (95% CI 0.19-0.47; P = 0.012), reduced BMI (95% CI 0.19-0.65; P = 0.02), and occupation (95% CI 0.12-0.84; P = 0.08). The mean BMI in males who currently smoked (n = 60; 19.29 kg/m(2); standard deviation [SD] 3.46) was significantly lower than in male never smokers (n = 33; 21.15 kg/m(2) SD 3.38; P < 0.001). AFO was observed in 27% of subjects with a BMI <18.5 kg/m(2), falling to 13% with a BMI ≥18.5 kg/m(2) (P = 0.013). AFO was observed in 11% of housewives, 22% of farm laborers, and 31% of cotton/jute workers (P = 0.035). CONCLUSION: In a rural Indian setting, AFO was related to advancing age, current or previous smoking, male gender, reduced BMI, and occupation. The data also suggest that being under-weight is linked with AFO and that a mechanistic relationship exists between low body weight, smoking tobacco, and development of AFO.

A study of patient attitudes in the United Kingdom toward ventilatory support in chronic obstructive pulmonary disease.

INTRODUCTION: Informed patient choice is central to modern clinical care but there is a paucity of data about how patients respond to information regarding complex therapies. This qualitative study aimed to understand the attitudes of patients with chronic obstructive pulmonary disease (COPD) toward acute ventilatory support and assess how aids to decision making regarding ventilation affect patients' views of therapy. METHODS: A standardized five-stage interview process was used to explore attitudes toward noninvasive ventilation (NIV) and invasive mechanical ventilation (IMV) in 50 stable COPD patients. RESULTS: Eighty-six percent found demonstration of NIV helpful in decision making compared to 24% with the photographic aid (p < 00.001). Although 96% were willing to receive NIV after a verbal description of the technique, only 76% consented when a photographic aid was shown. When NIV was demonstrated, willingness rose to 84%. While 60% were willing to receive IMV following a verbal description, this decreased to 58% following explanation of alternative treatments to IMV. Patients willing to receive IMV were younger (67 versus 76 years p = 0.016) and had a better functional status (NEADL index 20 versus 15 units p = 0.03). Only 34% had heard of advanced directives of care (ADCs), none had ever issued one but 48% expressed an interest in doing so following explanation of this process. CONCLUSION: COPD patients would find both explanation and demonstration of NIV useful in an outpatient setting. Worsening functional status along with advanced age was associated with reduced willingness to receive invasive ventilatory support. Awareness of ADCs was found to be low although almost half of the patients expressed interest in the uptake of ADCs following explanation of the process.

Risk assessment of pneumothorax and pulmonary haemorrhage complicating percutaneous co-axial cutting needle lung biopsy.

INTRODUCTION: The primary aim of this study was to evaluate the ability of radiologists to accurately estimate pneumothorax and pulmonary haemorrhage during percutaneous co-axial cutting needle CT-guided lung biopsy. METHODOLOGY: Patients undergoing cutting needle lung biopsy during the study period were identified; the path taken by the cutting needle marked on each pre-biopsy staging CT scan. Each scan was then reviewed independently by two thoracic radiologists blinded to clinical details and complications; pneumothorax and pulmonary haemorrhage risk estimated with a percentage Visual Analogue Scale. RESULTS: In 134 patients, pneumothorax occurred in 24%. The radiologists differed in the estimation of pneumothorax risk in 55% (74 episodes). When pneumothorax risk was estimated <20% by radiologists 1 and 2, 16% and 14% of biopsies resulted in pneumothorax; where risk was estimated at 20-49%, pneumothorax incidence rose to 33% and 31%; where risk was deemed > or =50%, pneumothorax rate was 87% and 100%. Pulmonary haemorrhage occurred in 4%; estimated haemorrhage risk for biopsies complicated by haemorrhage did not differ significantly from where haemorrhage did not occur. CONCLUSION: Radiologists differ markedly in the estimation of pneumothorax risk for a patient undergoing co-axial lung biopsy. Identifying individual patients developing pneumothorax was only possible when risk was estimated at > or =50%. Pulmonary haemorrhage was uncommon and difficult to predict accurately.

Ventilatory responses to inhaled carbon dioxide, hypoxia, and exercise in idiopathic hyperventilation.

Idiopathic hyperventilation (IH) is a poorly understood condition of sustained hypocapnia and controversial etiology. Although behavioral/emotional factors may contribute, it is uncertain whether chemosensitivity is altered, hyperventilation is maintained during exercise, and the associated breathlessness reflects the hyperventilation. In 39 patients with IH and 23 control subjects, we described ventilatory responses to isocapnic-hypoxia, hyperoxic-hypercapnia, and exercise; breath-hold tolerance; breathlessness; and psychologic status. Patients demonstrated hyperventilation at rest, with hypocapnia (28 +/- 3.8 mm Hg), a normal (slightly alkaline) arterial pH and [H(+)]a, and a significant base excess (-4.5 +/- 2.7 mEq/L), consistent with compensated respiratory alkalosis. Hyperventilation was sustained during exercise, despite hyperoxic-hypercapnic ventilatory responsiveness being normal and isocapnic-hypoxic ventilatory responsiveness being low relative to control (but exceeding control [2.4 +/- 1.0 vs. 1.6 +/- 0.5 L/min/%, p < 0.05] with acute restoration to normocapnia). Hyperventilation was maintained during exercise, at the resting CO(2) "setpoint." Relative to control, the breath-hold tolerance was attenuated, and dyspnea during exercise was significantly greater and not simply ascribable to the high ventilation. These observations suggest that patients with IH have a sustained hyperventilatory and dyspneic drive that, although not attributable to central chemosensitivity, may possibly have peripheral chemoreflex contributions. The nature and etiology of this chronic hyperventilatory drive remain unclear.