Rationale: Diaphragm dysfunction worsens outcomes in mechanically ventilated patients, but the clinical impact of potentially preventable changes in diaphragm structure and function caused by mechanical ventilation is unknown. Objectives: To determine whether diaphragm atrophy developing during mechanical ventilation leads to prolonged ventilation. Methods: Diaphragm thickness was measured daily by ultrasound in adults requiring invasive mechanical ventilation; inspiratory effort was assessed by thickening fraction. The primary outcome was time to liberation from ventilation. Secondary outcomes included complications (reintubation, tracheostomy, prolonged ventilation, or death). Associations were adjusted for age, severity of illness, sepsis, sedation, neuromuscular blockade, and comorbidity. Measurements and Main Results: Of 211 patients enrolled, 191 had two or more diaphragm thickness measurements. Thickness decreased more than 10% in 78 patients (41%) by median Day 4 (interquartile range, 3–5). Development of decreased thickness was associated with a lower daily probability of liberation from ventilation (adjusted hazard ratio, 0.69; 95% confidence interval [CI], 0.54–0.87; per 10% decrease), prolonged ICU admission (adjusted duration ratio, 1.71; 95% CI, 1.29–2.27), and a higher risk of complications (adjusted odds ratio, 3.00; 95% CI, 1.34–6.72). Development of increased thickness (n = 47; 24%) also predicted prolonged ventilation (adjusted duration ratio, 1.38; 95% CI, 1.00–1.90). Decreasing thickness was related to abnormally low inspiratory effort; increasing thickness was related to excessive effort. Patients with thickening fraction between 15% and 30% (similar to breathing at rest) during the first 3 days had the shortest duration of ventilation. Conclusions: Diaphragm atrophy developing during mechanical ventilation strongly impacts clinical outcomes. Targeting an inspiratory effort level similar to that of healthy subjects at rest might accelerate liberation from ventilation.

To review the efficacy of the current diagnostic methods of acute compartment syndrome (ACS) after leg fractures. A Medline (PubMed) search of the English literature extending from 1950 to May 2007 was performed using "compartment syndromes" as the main key word. Also a manual search of orthopaedic texts was performed. The results were limited to articles involving human subjects. Of 2605 primary titles, 489 abstracts limited to compartment syndromes in the leg and 577 articles related to the diagnosis of compartment syndromes were identified and their abstracts reviewed. Further articles were identified by reviewing the references. Sixty-six articles were found to be relevant to diagnostic techniques for compartment syndrome in the leg and formed the basis of this review. Early diagnosis of an ACS is important. Despite its drawbacks, clinical assessment is still the diagnostic cornerstone of ACS. Intracompartmental pressure measurement can confirm the diagnosis in suspected patients and may have a role in the diagnosis of this condition in unconscious patients or those unable to cooperate. Whitesides suggests that the perfusion of the compartment depends on the difference between the diastolic blood pressure and the intracompartmental pressure. They recommend fasciotomy when this pressure difference, known as the Delta p, is less than 30 mm Hg. Access to a precise, reliable, and noninvasive method for early diagnosis of ACS would be a landmark achievement in orthopaedic and emergency medicine.

BACKGROUND: Maximal inspiratory pressure (MIP) is the most commonly used measure to evaluate inspiratory muscle strength. Normative values for MIP vary significantly among studies, which may reflect differences in participant demographics and technique of MIP measurement.OBJECTIVE: To perform a systematic review with meta‐analyses to synthesize MIP values that represent healthy adults.METHODS: A systematic literature search was conducted using Medline, EMBASE, Cochrane, Cumulative Index to Nursing and Allied Health (CINAHL) and Sport Discus databases. Two reviewers identified and selected articles, and abstracted data. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. A random‐effects model was used to calculate overall means and 95% CIs.RESULTS: Of 22 included articles, MIP data were synthesized according to age group and sex from six reports (n=840) in the meta‐analyses. The mean QUADAS score was 3.5 of 7. The age range was between 18 and 83 years (426 men, 414 women). MIP began to decrease with age in the 40 to 60 years age range and continued to fall progressively with age. For the same age group, men tended to have higher MIPs than women. Sensitivity analysis of withdrawing studies from the meta‐analysis identified one study that contributed more to heterogeneity in some age groups.DISCUSSION: MIP was higher in men and decreased with age, which was initially apparent in middle age. Several characteristics of participants and MIP technique influence values in healthy individuals.CONCLUSIONS: The present meta‐analysis provides normative MIP values that are reflective of a large sample (n=840) and likely represents the broadest representation of participant characteristics compared with previous reports of normative data.