Analysis of resistance to gas flow in nine adult ventilator circuits

We measured the resistance in nine complete ventilator circuits, partial circuits and 7, 8, and 9 mm ID endotracheal tubes at flow rates of 20 to 120 liters per minute. We found a statistically significant (p less than 0.01) increase in resistive pressure with increases in flow rate, as the diameter of the ETT decreased, and as each component of the ventilator circuit was added to the ETT. There was a curvilinear increase in resistive pressure to increase in flow rate. However, when resistances were computed, the Bennett cascade "circuit" created higher resistance at 20 lpm than at flow rates up to 120 lpm. The Bennett cascade humidifier added the greatest resistive pressure, 3.5 to 8.5 cm H2O, the Engstrom Edith, 0.5 to 6.5 cm H2O, and the Conchapak added the least, 0.0 to 2.5 cm H2O at flow rates of 20 to 120 lpm. After all the components of the ventilator circuit were attached to the ETTs, there was approximately a 97 to 450 percent increase in resistive pressure compared to the resistive pressure created by the ETTs alone.     

Transdermal microconduits by microscission for drug delivery and sample acquisition

Background  

Painless, rapid, controlled, minimally invasive molecular transport across human skin for drug delivery and analyte acquisition is of widespread interest. Creation of microconduits through the stratum corneum and epidermis is achieved by stochastic scissioning events localized to typically 250 μm diameter areas of human skin in vivo.     

Psychiatric specialty clinics: do they weed out comorbid depression and anxiety?

The concept of comorbidity of anxiety and depression was examined as it relates to specialty clinics, a growing trend as mental health care providers attempt to compete for patients and provide efficient and specialized treatments. Twenty-nine patients from an anxiety clinic were compared with 23 patients from a mood disorders clinic in a university-based outpatient setting. Axis I diagnoses obtained by structured clinical interview for DSM-III-R were generally consistent with each specialty clinic. Incidence of diagnosable comorbid anxiety and mood disorders was not significantly different for the two clinics and within the range cited (11-78%) in several other studies drawing from various patient populations. Similarly, in comparing self-reported symptoms on three rating scales using Student's tests, authors found elevated symptoms of both depression and anxiety in both clinic populations. The importance of addressing the needs of patients with co-occurring diagnoses and symptoms within a specialty clinic is discussed as it pertains to treatment and research.