Does splanchnic ischemia occur in isolated neurotrauma? A prospective observational study.

OBJECTIVE: To characterize the incidence and severity of splanchnic ischemia, as defined by gastric tonometry, in patients with isolated severe head injury and to examine the relationship between cerebral hemodynamics and splanchnic ischemia. DESIGN: Prospective observational study. SETTING: Neurosurgical intensive care unit in a tertiary referral center. PATIENTS: Ten patients with severe neurotrauma. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The mean arterial pressure, intracranial pressure, and gastric mucosal P(CO2) measurements were recorded at 15-min intervals. Intramucosal pH was calculated every 3 hrs. All patients received stress ulcer prophylaxis. Nine patients received noradrenaline infusions to maintain a target cerebral perfusion pressure of 70 mm Hg. The mean baseline gastric mucosal P(CO2) and intramucosal pH were 38+/-10 torr and 7.38+/-0.1 pH units, respectively. Nine patients manifested low intramucosal pH during the study period. Gastric mucosal P(CO2) values ranged from 36 to 132 torr. Intramucosal pH measurements ranged from 6.9 to 7.47. The mucosal gap ranged from -12 to +93 torr (mean +/- SD, 17+/-17 torr). The pH gap ranged from -0.1 to +0.54 pH units (mean +/- SD, 0.14+/-0.11 pH units). There was no statistically significant relationship between cerebral hemodynamics, the use of inotropes, and gastric mucosal P(CO2), or intramucosal pH. CONCLUSIONS: Splanchnic ischemia (intramucosal pH, <7.3) occurs commonly in isolated neurotrauma, with a statistically nonsignificant trend toward development of mucosal ischemia with decreased cerebral perfusion.     

ACOEM position statement. Spirometry in the occupational setting. American College of Occupational and Environmental Medicine

This position statement reviews several aspects of spirometric testing in the workplace, where spirometry is employed in the primary, secondary, and tertiary prevention of occupational lung disease. Primary prevention includes pre-placement and fitness-for-duty examinations as well as research and monitoring of health status in groups of exposed workers; secondary prevention includes periodic medical screening of individual workers for early effects of exposure to known occupational hazards; and tertiary prevention includes clinical evaluation and impairment/disability assessment. For all of these purposes, valid spirometry measurements are critical, requiring: documented spirometer accuracy and precision, a rigorous and standardized testing technique, standardized measurement of pulmonary function values from the spirogram, adequate initial and refresher training of spirometry technicians, and, ideally, quality assessment of samples of spirograms. Interpretation of spirometric results usually includes comparison with predicted values and should also evaluate changes in lung function over time. Response to inhaled bronchodilators and changes in relation to workplace exposure may also be assessed. Each of these interpretations should begin with an assessment of test quality and, based on the most recent ATS recommendations, should rely on a few reproducible indices of pulmonary function (FEV1, FVC, and FEV1/FVC.) The use of FEF rates (e.g., the FEF25-75%) in interpreting results for individuals is strongly discouraged except when confirming borderline airways obstruction. Finally, the use of serial PEF measurements is emerging as a method for confirming associations between reduced or variable pulmonary function and workplace exposures in the diagnosis of occupational asthma. Throughout this position statement, ACOEM makes detailed recommendations to ensure that each of these areas of test performance and interpretation follow current recommendations/standards in the pulmonary and regulatory fields. Submitted by the Occupational and Environmental Lung Disorder Committee on November 16,1999. Approved by the ACOEM Board of Directors on January 4,2000.     

IL-4 induces characteristic Th2 responses even in the combined absence of IL-5, IL-9, and IL-13

Functional redundancy is highly prevalent among the Th2 interleukins (IL)-4, IL-5, IL-9, and IL-13. To define the critical functions of these cytokines, we have generated a novel panel of compound Th2 cytokine-deficient mice (from single to quadruple cytokine knockouts). We find that these Th2 cytokines are not essential for fetal survival even during allogeneic pregnancy. Using intestinal parasite infection and a pulmonary granuloma model, we demonstrate cryptic roles for IL-4, IL-5, IL-9, and IL-13 in these responses. Significantly, although IL-5, IL-9, and IL-13 add to the speed and magnitude of the response, a threshold is reached at which IL-4 alone can activate all Th2 effector functions. These mice reveal distinct spatial, temporal, and hierarchical cytokine requirements in immune function.     

Stabilized subcutaneous ulnar nerve transposition with immediate range of motion. Long-term follow-up

BACKGROUND: Anterior transposition of the ulnar nerve at the elbow produces generally good results regardless of whether the nerve is transposed subcutaneously, intramuscularly, or submuscularly. The eventual recovery of nerve function is related less to the specific surgical technique than to the severity of the intrinsic nerve pathology. A primary variable in surgical management is the duration of postoperative elbow immobilization. The purpose of this study was to review the longterm results of a specific technique of subcutaneous anterior transposition of the ulnar nerve that utilizes a stabilizing fasciodermal sling. The study compared the results of immediate and late institution of a range of motion postoperatively. METHODS: Forty-seven patients with fifty-one elbows were reexamined, by an investigator who had not been involved in their treatment, at a minimum of two years (range, twenty-four months to fourteen years) after an anterior transposition. Of the fifty-one elbows, twenty-one were immobilized for two to three weeks whereas thirty were managed with an immediate range of motion. RESULTS: At the latest follow-up evaluation, there were occasional, mild paresthesias in 16 percent of the limbs and there was still subjective weakness of 19 percent. Both pinch and grip strength had increased substantially. No patient had lost elbow motion. A positive Tinel sign persisted in 31 percent of the limbs, but it was mildly positive in most of them. The elbow flexion test was uniformly negative. The results for 92 percent of the limbs were satisfactory to the patients, who stated that they would undergo the same procedure again if necessary. Overall, 73 percent of the limbs had an excellent result; 18 percent, a good result; 4 percent, a fair result; and 6 percent, a poor result. With the numbers available, no significant difference could be detected, with regard to these outcomes, between the group managed with elbow immobilization and that managed with immediate elbow mobilization. However, patients treated with a postoperative cast returned to work at an average of thirty days after surgery whereas the group treated with immediate motion of the elbow returned to work at an average of ten days. CONCLUSIONS: This technique of stabilized subcutaneous anterior transposition of the ulnar nerve yielded predictably good results for a wide spectrum of patients. Patients returned to their occupation sooner when the elbow had been mobilized immediately.