Peter White

Prospective, randomized, controlled clinical trial comparing traditional versus reduced tidal volume ventilation in acute respiratory distress syndrome patients

OBJECTIVE To assess the safety and potential efficacy of a mechanical ventilation strategy designed to reduce stretch-induced lung injury in acute respiratory distress syndrome. DESIGN Prospective, randomized, controlled clinical trial. SETTING Eight intensive care units in four teaching hospitals. PATIENTS Fifty-two patients with acute respiratory distress syndrome. INTERVENTIONS Traditional tidal volume patients: tidal volume 10-12 mL/kg ideal body weight, reduced if inspiratory plateau pressure was > 55 cm H2O (7.3 kPa). Small tidal volume patients: tidal volume 5-8 mL/kg ideal body weight, to keep plateau pressure < 30 cm H2O (4.0 kPa). MEASUREMENTS AND MAIN RESULTS Mean tidal volumes during the first 5 days in traditional and small tidal volume patients were 10.2 and 7.3 mL/kg, respectively (p < .001), with mean plateau pressure = 30.6 and 24.9 cm H2O (3.3 kPa), respectively (p < .001). There were no significant differences in requirements for positive end-expiratory pressure or FIO2, fluid intakes/outputs, requirements for vasopressors, sedatives, or neuromuscular blocking agents, percentage of patients that achieved unassisted breathing, ventilator days, or mortality. CONCLUSIONS The reduced tidal volume strategy used in this study was safe. Failure to observe beneficial effects of small tidal volume ventilation treatment in important clinical outcome variables may have occurred because a) the sample size was too small to discern small treatment effects; b) the differences in tidal volumes and plateau pressures were modest; or c) reduced tidal volume ventilation is not beneficial.

Investigating Acupuncture Using Brain Imaging Techniques: The Current State of Play

We have systematically researched and reviewed the literature looking at the effect of acupuncture on brain activation as measured by functional magnetic resonance imaging and positron emission tomography. These studies show that specific and largely predictable areas of brain activation and deactivation occur when considering the traditional Chinese functions attributable to certain specific acupuncture points. For example, points associated with hearing and vision stimulates the visual and auditory cerebral areas respectively. Pain, however, is a complex matrix that is intimately intertwined with expectation. Acupuncture clearly affects this matrix in both specific and non-specific manner that is consistent with its specific clinical effects, as well as the effects of expectation on pain relief. This article summarizes the current imaging literature.

Loss of chromosome arms 3p and 9p and inactivation of P16INK4a in normal epithelium of patients with primary lung cancer

The accumulation of genetic alterations in the respiratory epithelium may give rise to cancer and often is accompanied by a series of histologic alterations over a period of several years. Recent studies have identified some molecular alterations in histologically normal‐appearing epithelium among patients with lung cancer. To extend these observations, we investigated clonal genetic alterations by using fluorescence in situ hybridization (FISH) analysis and immunohistochemistry in 69 biopsy samples of histologically normal‐appearing bronchial epithelium from 22 patients with or without lung cancer. Thirty‐seven biopsy specimens from 13 patients were examined for loss of 3p14, and 48 biopsy specimens from 18 patients were examined for loss at 9p21 by FISH. P16INK4a expression was analyzed in 54 biopsy samples from 19 patients. In at least one biopsy specimen from five of the13 patients with primary lung cancer, FISH or immunohistochemistry detected loss of the 3p14 or 9p21 region. In contrast, no alterations were detected for the same regions in the nine patients without primary lung cancer. Our results support the concept that the normal epithelial surface of large bronchi of patients with lung cancer has molecular changes suggestive of the outgrowth of numerous clonal foci.

Nonsegmental ventilation-perfusion scintigraphy mismatch after radiation therapy.

PURPOSE This report illustrates the utility of ventilation-perfusion scintigraphy in differentiating radiation pneumonitis from other causes of dyspnea, including pulmonary embolism, heart failure, obstructive tumor, and chronic obstructive pulmonary disease. METHODS AND RESULTS A nonsegmental mismatched perfusion abnormality, which exactly conformed to a radiation port, was diagnostic of radiation pneumonitis. CONCLUSION In patients with lung tumors presenting with dyspnea, ventilation-perfusion scintigraphy may be useful in diagnosing radiation pneumonitis and effectively excluding other causes of dyspnea.