Incidence of pressure ulcers in intensive care units and direct costs of treatment: Evidence from Iran

Background and objective

Pressure ulcer (PU) is one of the important and frequent complications of hospitalization, associated with high treatment costs. The present study was conducted to determine the incidence of PU and its direct treatment costs for patients in intensive care unit (ICU) in Iran.

两种不同方法测定低水平压力支持通气时气道阻断压与自主呼吸时常规方法测定值的相关性分析

目的 拟比较以两种不同方法测定低水平压力支持通气（pressure support ventilation，PSV）病人的气道阻断压（P0．1）与自主呼吸时常规方法测定值的相关性。方法 12例机械通气病人，断开呼吸机自主呼吸时以常规方法测定P0．1得到P0．1-SB：在PSV水平为5cmH20，以常规方法和按压呼气末暂停键测定P0．1分别得到P0．1-PSV5和P0．1-PSV5eeo．分析后二者与前者之间的相关性。结果 P0．1-SB与P0．1-PSV5之间差异无显著性，P0．1-PSV5ee0分别小于P0．1-SB与P0．1-PSV5，差异有显著性；P0．1-PSV5eeo与P0．1-PSV5和P0．1-SB之间的相关系数均为0．97。结论 按压呼气末暂停键测定PSV水平为5cmH2O的P0．1值与常规方法测定的PSV水平为5cmH2O以及自主呼吸时的测定值相比，其值偏小,但前者与后二者之间具有良好的相关性。     

Implication of the systolic hump in systemic arterial pressure waves

The systolic hump in the aortic blood pressure wave is defined as the aorticresistance component proportional to the aortic blood flow superimposed on the windkessel component. An electrical analogue comprising a series resistance (aortic resistance) plus a resistance (peripheral resistance) and capacitance (aortic compliance) in parallel (i.e. windkessel component) is used for analysis. Curve fitting using the leastsquares method is performed on calculated and measured blood pressure waves from dogs under haemodynamical conditions induced by infusion of three drugs (noradrenaline, isoproterenol and acetylcholine). The curve fitting RMS (root mean square) errors are <3% for blood pressure waves and <30% for blood flow waves, with good agreement between measured and calculated blood flow waveforms. Infusion of noradrenaline and acetylcholine is found to induce a significant decrease and increase in the aortic resistance, respectively. Although only a small fraction of the blood pressure wave, the systolic hump has a marked effect on the systolic pressure waveform.     

Changes in temporal gait characteristics and pressure distribution for bare feet versus various heel heights

The purpose of this study was to identify changes in temporal gait characteristics and pressure generation across the sole of the foot due to various heel heights in women's dress pumps. Thirty female subjects, aged 18-30 years, volunteered to participate. Subjects were required to have normal gait and to wear comfortably either size 7 or size 9 shoes. Subjects were tested initially in bare feet using electrodynography (Langer Biomechanics Group, 21 East Industry Court, Deer Park, NY 11729-9986) (EDG) at a cadence of ~100 steps/min set by metronome. EDG trials with 4 pairs of shoes were then performed in random order. Shoes were women's dress pumps identical except for heel height. Heel heights were 1.75, 3.12, 5.72 and 8.74 cm. Data were collected over ~ 30 steps and averaged over this period. Data were analyzed using a one-way ANOVA, and changes were only considered significant if the ANOVA identified significant variations bilaterally. Considering temporal gait variables, we concluded that: (1) stance phase was shortened in shoes vs. bare feet but was unaffected by heel height, (2) the percentage of stance spent in weight bearing on the lateral and medial calcaneus decreased above a 3.12 cm heel height, (3) the percentage of stance spent in weight bearing on the first and second metatarsal heads increased in shoes vs. bare feet but was unaffected by heel height, (4) the percentage of stance spent in weight bearing on the fifth metatarsal was less in the 8.74 cm heel than in any other shoe or in bare feet. With regard to pressure variables, we found that: (1) peak pressure under the fifth metatarsal head was inversely related to heel height, (2) pressure under the third metatarsal head peaked earliest in heels greater than 5.72 cm high, and (3) pressure under the medial calcaneus peaked latest in heels greater than 5.72 cm high.     

A simple dual pressure-ejection system and calibration method for brief local applications of drugs and modified salines

We report a minimal method for dual pressure ejection through a single micropipette, which uses standard theta-type glass tubing and a connection through thinned polythene catheters without any sealing. We also describe a simple calibration method using a standard electrometer. The linearity of the ejected volume with respect to pulse duration and to applied pressure was maintained, as measured by the resistivity of ultrapure water after ejection of a saline solution. The method was used to analyse the inhibitory effect of glutamate on crayfish motoneurones with local and reversible applications of low-chloride saline and picrotoxin.     

In vitro determination of lung airway compliance in small animals

An in vitro method for obtaining pressure/volume curves from the lungs of small animals is described. The excised lungs were inflated and deflated with saline or air by a motor-driven syringe controlled by a microcomputer. The computer was programmed to display the curves in real time, correcting when necessary for the compressibility of air in the system. Volume compliance (K=dV/dP×1/V) was calculated by differentiating a polynomial fitted to the measured pressure/volume points. Repeatable curves were obtained from mice aged 24h (body weight 1·3±0·14g (SD), residual lung volume 8·43±1·5 μl (SD). A nonlinear decrease in differential compliance (K=dV/dP×1/V) with increasing strain was observed while the ratio K_saline/K_air increased from 2·5 to 10 over the range of strains investigated (ε=1–5). The relative surface tension (calculated from the difference between the pressures required to inflate the air and saline-filled organs to a given volume) increased exponentially with increasing volume. We conclude that it is now possible to obtain reproducible pressure/volume curves for lungs with a residual volume of less than 10 μl, from animals weighing approximately 1·5 g and, from these curves, estimate airway compliance and surface tension.     

Clinical and manometric evaluation of anorectal function following low anterior resection with low anastomotic line using an EEA™ stapler for rectal cancer

Anorectal function was evaluated in eight patients who had low anterior resection of the rectum with a low anastomotic line, using an EEA^™ stapler, with determination of function based on periodic manometric studies and clinical symptoms. Immediately following surgery all patients suffered from frequent bowel actions and soiling. These symptoms improved with time and most patients could enjoy almost normal daily life by the sixth postoperative month. One month after surgery, anal canal resting pressure and maximum squeeze pressure were significantly reduced and rectoanal inhibitory reflex was absent; neither showed a distinct tendency to improve thereafter. Rectal sensation and reservoir capacity, which also were seriously impaired, recovered satisfactorily by the time of the six-month examination. This suggests that an improvement of clinical symptoms following this operation is dependent upon the recovery of reservoir capacity and sensation of the neorectum, and that this operative procedure is a functionally acceptable option for low rectal cancer.     

Drinking History Is Related to Persistent Blood Pressure Dysregulation in Postwithdrawal Alcoholics

We have previously demonstrated that alcoholics with transitory (< 72 hr) elevations in blood pressure (BP) during withdrawal continue to show residual cardiovascular dysregulation up to 4 weeks of abstinence. The present study replicates and extends these findings. Alcoholic inpatients were divided into three subgroups ( ns = 14) based on BP during the first 72 hr of withdrawal: transitory hypertensives (tHTs; BP > 160/95 mm Hg), transitory borderline hypertensives (tBHs; 140/90 BP < 160/95), and normotensives (NTs; all BPs < 140/90). All patients had normal resting pressures after 72 hr of withdrawal. At 3–4 weeks postadmission, the alcoholics and 14 nonalcoholic controls (CONTs) were tested at rest and during a 5-min handgrip task. The tHTs showed an exaggerated systolic and diastolic BP response to handgrip compared with NTs and CONTs, with tBHs intermediate ( ps < 0.05). Drinking history showed the tHTs had the highest reported level of alcohol consumption and severity of withdrawal symptoms ( ps < 0.05). Regression analyses indicated that consumption of hard liquor was the variable most predictive of admission BPs; further, parental history of hypertension potentiated this relationship for systolic BP. Age and consumption of nicotine and caffeine were not significant predictors of admission BP. The results suggest a persistent cardiovascular dysregulation in alcoholics showing transient hypertensive withdrawal BPs. These alcoholics may be at increased risk for future alcohol-related cardiovascular disorder.     

原发性高血压和血液流变学异常之间的关系的研究

目的探讨原发性高血压病和血液流变学异常改变之间的关系。方法对80例高血压病人进行血液流变学观察。结果原发性高血压病组血液流变学多项指标出现异常升高,与正常对照组比较差异有显著性,其主要表现为全血粘度增高,其增高程度和血压升高程度之间呈正相关趋势。其中红细胞压积增高可能是血液粘度增高的重要因素。结论高血压病患者的血液流变学异常和血压增高程度之间有密切相关性。