Biomedical subjects
J D Whitney
Publications and source records attributed to J D Whitney.
Wound tissue oxygen tension predicts the risk of wound infection in surgical patients.
OBJECTIVE: To test the hypothesis that subcutaneous wound oxygen tension (PsqO2) has a predictive relation to the development of wound infection in surgical patients. DESIGN: A noninterventional, prospective study. SETTING: A university department of surgery. PATIENTS: One hundred thirty operative general surgical patients at notable risk of infection as predicted by an anticipated Study on the Effect of Nosocomial Infection Control (SENIC) score of 1 or greater. OUTCOME MEASURES: PsqO2 was measured perioperatively. Its relation to the subsequent incidence of surgical wound infection was then determined and compared with the SENIC score as a criterion standard. RESULTS: Although the SENIC score and PsqO2 are inversely correlated, PsqO2 is the stronger predictor of infection. Low PsqO2 identified patients at risk and concentrated them in a cohort that was about half the size of that identified by the SENIC score. CONCLUSIONS: Subcutaneous perfusion and oxygenation are important components of immunity to wound infections. The SENIC score identifies systemic physiological variables that are important to the development of wound infection. Nevertheless, PsqO2 is the more powerful predictor of wound infection. Moreover, PsqO2 can be manipulated by available clinical means, and thus may direct interventions to prevent infection.
Effects of 72 hours sleep deprivation on wound healing in the rat.
The purpose of this study was to examine effects of sleep deprivation on cellular and biochemical markers of wound healing. Expanded polytetrafluoroethylene tubing inserted in subcutaneous tissue created miniature wounds in the dorsal skin of 12 rats. Seven days later, 6 rats were deprived of sleep by the platform method for 72 hr; control rats remained on usual sleep/wake routines. Numbers of macrophages, granulocytes, fibroblasts, and extent of connective tissue present and total amounts of protein, DNA, and hydroxyproline in the implants were not different between sleep-deprived and control rats. There is no evidence from this study that sleep deprivation impairs cellular and biochemical indicators of tissue repair.
Effects of dynamic exercise on subcutaneous oxygen tension and temperature.
Exercise influences blood flow distribution and may thereby influence tissue oxygen. Given that experimental evidence suggests exercise improves wound healing, this study was undertaken to determine the effect of exercise on subcutaneous tissue oxygen tension (PscO2). Subjects performed a treadmill test to maximum oxygen consumption (VO2) while PscO2 and subcutaneous temperature (Tsc) were measured using a tonometer and optode/thermocouple system. There were no significant differences in PscO2 between measurement points. Mean Tsc had increased 4.8% at maximum VO2, and 6.3% as the cool-down period ended and differed significantly across the exercise period. Changes in PscO2 and Tsc were not correlated. Oxygen availability was neither enhanced nor significantly reduced by exercise. However, PscO2 did not increase as expected in relation to increases in Tsc. Further study will determine the purported beneficial effects of exercise and the mechanism by which it may affect wound healing.
Pulsed microamperage stimulation: a controlled study of healing of surgically induced wounds in Yucatan pigs.
BACKGROUND AND PURPOSE: Microamperage direct current and microamperage electromagnetic stimulation are used to accelerate healing in bone. Although many clinicians are using microamperage stimulation to relieve pain and facilitate wound healing, there is significant question regarding whether this low-intensity direct current significantly accelerates soft tissue wound repair. The purpose of this study was to determine whether low-voltage pulsed microamperage current (100 microA, 60 V, 0.1 Hz) enhances the healing of superficial, full-thickness, or incisional wounds created to simulate acute abrasions, ulcers, and lacerations. SUBJECTS: Ten adult Yucatan mini pigs served as the subjects for this study. METHODS: Variables associated with healing were measured in 60 matched pairs of surgically induced partial-thickness, full-thickness, and incisional wounds after either sham or anodal (positive-polarity) stimulation with pulsed microamperage current (100 microA) was administered for 1 hour per day for 5 days. Sterile, disposable electrodes (2 x 4 cm) were placed over each wound, which was kept wrapped and protected throughout the study. RESULTS: At 7 days postinjury, all wounds were healing well with no signs of infection. There were no differences in tensile strength, collagen density, maturity, or deposition (hydroxyproline), wound size, or visual appearance between the sham treatment and treatment lesions. No changes in local subcutaneous oxygen or temperature were found in the swine during or after microamperage stimulation. CONCLUSION AND DISCUSSION: This study did not provide any evidence to support the use of microamperage stimulation to accelerate wound healing. No negative effects, however, were found. Further research is needed to determine whether there is a critical interaction between the size of the electrode relative to the wound, the density of the current, the duration of the treatment, the polarity of the treatment electrode, and the acuity or chronicity of wounding and the effectiveness of microcurrent stimulation for wound healing.
Low-dose ultrasound effects on wound healing: a controlled study with Yucatan pigs.
This study reports on the effect of low-dose ultrasound in accelerating wound healing in matched pairs of surgically induced incisions and full-thickness and partial-thickness lesions in 11 Yucatan mini-pigs after 7 days of healing and 5 days of sonation. Tensile strength, collagen deposition (hydroxyproline), reduction in wound size (full-thickness lesion), and mast-cell degranulation were significantly greater in the sonated lesions than in the sham-treated controls (p = 0.01). Sonation enhanced strength by 24% and collagen deposition by 29%, when compared with controls. There were no significant differences in the quality of healing as measured by an ordinal scale. The results suggest that within the first week of healing, low-dose ultrasound facilitates wound healing. More research is needed to confirm the most effective dose, frequency, and treatment duration and intervention time for maximum healing.
Inter-laboratory variation in gluten detection by ELISA kit.
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Nutritional intake and status of clients in the home with open surgical wounds.
The purpose of this study was to determine (a) whether the nutritional intake of patients at home with wounds healing by secondary intention was adequate to support healing, and (b) the nutritional status of these patients. Nineteen subjects with a mean age of 65.3 years were accrued. Of the 17 subjects for whom nutritional intake data were available, 16 had insufficient caloric intake to support healing and over half had less than the Recommended Daily Allowance (RDA) of protein. Using the RDA as a conservative measure of vitamin and mineral need with injury, Vitamin C intake was decreased in approximately one third of the subjects, while all but one had decreased zinc intake. Over two thirds of the subjects reported a decrease from their usual weight and all the subjects measured had triceps skin fold (TSF) and mid-arm muscle circumference (MAMC) which were below the first and second Health and Nutrition Examination Surveys (HANES I & II) median. Mean serum albumin of the sample was below normal. The nutritional intake of these patients needs increased attention. Community health nurses (CHNs) need to assess nutritional status and monitor the intake of patients with wounds. Future research needs to address why intake is decreased and test strategies to increase oral intake.
The influence of tissue oxygen and perfusion on wound healing.
The availability of oxygen (O2) to cells in the wound area and the presence of adequate blood flow are important factors to the healing process. Oxygen plays a critical role in the formation of collagen, the growth of new capillaries, and the control of infection. Perfusion and delivery of O2 to tissue are closely related. Although an adequate blood flow does not guarantee a sufficient supply of O2, without it the provision of O2 to healing tissues will be impaired. Basic scientific studies have clarified how O2 and blood flow influence healing. Recent research has focused on clinical populations and begins to provide direction for additional clinical studies and interventions to support the healing process. Based on existing research, clinical interventions aimed to maintain perfusion and supply of O2 include fluid volume assessments, pulmonary hygiene regimens, postoperative position changes, and ambulation.
Physiologic effects of tissue oxygenation on wound healing.
Researchers have documented the importance of oxygen as a substrate during tissue healing. Development of knowledge in this area is primarily based on studies conducted in animals with limited studies of tissue oxygen tensions in human beings. However, investigators have consistently shown that a sufficient oxygen supply to tissue is critical to the healing process and the avoidance of wound infection. Research in the area of tissue oxygenation and wound healing is reviewed and implications for nursing practice and research are proposed. Studies that will address the effect of clinical interventions on physiologic processes, such as oxygen delivery to healing tissues, are needed to expand the scientific foundation for nursing practice.
A guide for nursing assessment of the psychiatric inpatient.
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Nursing diagnosis of patients with manic and thought disorders.
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A validation study of the nursing diagnosis "somatization".
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Establishing predictive validity of a patient classification system.
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Nursing diagnosis of depression.
To summarize, based on a sample of six subjects who were depressed, 12 nursing diagnoses were identified. Five of the 12 diagnoses occurred in more than one subject. Criteria for making a diagnosis were specified, and the diagnoses and their defining characteristics were examined for principles of classification.
Do mattresses make a difference?
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