Foley drainage tubing configuration affects bladder pressure: a bench model study.

A bench model was created to measure and analyze pressures in a simulated bladder and an actual urine drainage system. Fluid-filled dependent (generally U-shaped) loops in the urine drainage tubing generated back-pressure (in units of cm H2O), directly related to the difference in fluid meniscus heights (in units of cm) across the dependent loop that interfered with emptying of the simulated bladder. If the results obtained with a simulated bladder occur in actual bladders with indwelling urinary catheters, retained urine volume (that can promote urinary tract infection) will increase with larger differences in meniscus heights across the dependent loop due to increased back-pressure. Dependent loops in urine drainage tubing should be avoided. If the dependent loops cannot be avoided or a configuration without dependent loops cannot be maintained, they should be routinely emptied of urine, especially if the bag-side meniscus is higher than the bladder-side meniscus.

Patient repositioning and pressure ulcer risk--monitoring interface pressures of at-risk patients.

Repositioning patients regularly to prevent pressure ulcers and reduce interface pressures is the standard of care, yet prior work has found that standard repositioning does not relieve all areas of at-risk tissue in nondisabled subjects. To determine whether this holds true for high-risk patients, we assessed the effectiveness of routine repositioning in relieving at-risk tissue of the perisacral area using interface pressure mapping. Bedridden patients at risk for pressure ulcer formation (n = 23, Braden score <18) had their perisacral skin-bed interface pressures recorded every 30 s while they received routine repositioning care for 4-6 h. All participants had specific skin areas (206 +/- 182 cm(2)) that exceeded elevated pressure thresholds for >95% of the observation period. Thirteen participants were observed in three distinct positions (supine, turned left, turned right), and all had specific skin areas (166 +/- 184 cm(2)) that exceeded pressure thresholds for >95% of the observation period. At-risk patients have skin areas that are likely always at risk throughout their hospital stay despite repositioning. Healthcare providers are unaware of the actual tissue-relieving effectiveness (or lack thereof) of their repositioning interventions, which may partially explain why pressure ulcer mitigation strategies are not always successful. Relieving at-risk tissue is a necessary part of pressure ulcer prevention, but the repositioning practice itself needs improvement.

Thermal damage of the humidified ventilator circuit in the operating room: an analysis of plausible causes.

Fire in the operating room is a rare but potentially devastating event. In this case report, we describe 2 separate fires of a Westmed heated humidification circuit. We conducted a detailed analysis of potential causes of the fires, including a simulation and series of experiments. Our conclusions were (1) a combination of factors led to the fires; and (2) substantial changes in the design could decrease, but may not completely eliminate, the risk of operating room fire.