Effects of compression and type of bed surface on the microcirculation of the heel

Objective:To assess the effects of compression on the skin microcirculation of the heel using laser Doppler fluxmetry.Design:Parallel groups comparing patients with control groups.Setting:Department of Surgery, University College London Medical School, London.Subjects and Materials:Ten patients at risk of developing pressure ulceration, 10 age- and sex-matched healthy subjects and 10 young, healthy volunteers. An acrylic indenter with a slot to accommodate a laser Doppler probe was used to apply compression to the heel region. A pressure sensor was used to measure the applied compression.Outcome measures:The resting laser Doppler flux was measured with the subject lying supine. Compression forces were then applied in increments from 50g to 1500g and the corresponding interface pressure (IP) and laser Doppler flux (LDF) recorded. The IP and LDF were also measured from the heel while the subject was lying on a low air-loss system and then on an NHS conventional hospital bed.Results:The resting LDF is lower in the patient group compared to the control groups (p < 0.05). Compression of the heel caused a progressive decrease in LDF in all groups. Compression greater than 50 mmHg as well as lying on an NHS bed reduced the LDF signal to a minimal value (biological zero). On the low air-loss system, the median LDF was 17% of the resting value in the age-matched control group and 32% in the patient group.Conclusions:The results indicate that the heel microcirculation is vulnerable to compression. The low air-loss system maintained the IP sufficiently low to prevent complete cessation of the heel microcirculation

Assessment of Intermittent Pneumatic Compression by Strain-Gauge Plethysmography

Objective: To compare the physiological effects of a sequential gradient pneumatic compression device (SCD) with a single-chamber pneumatic compression device (Venodyne). Design: Single patient group with treatment crossover. Setting: Department of Surgery, University College and Middlesex Hospital, London, UK. Subjects: Thirty-four limbs of 17 normal adult volunteers were studied. Interventions: Sequential gradient compression was applied to one leg and single-chamber compression to the other lower limb for 10 min. The compression devices were then swapped to the opposite leg for a further 10 min period. Outcome measures: The increase in foot volume (distal venous distension) in response to each compression, and the subsequent decrease in foot volume (distal venous emptying), were measured. The overall reduction of foot volume (net effect) during the period of compression was calculated. Results: The results indicate the net effect was a decrease in foot volume (median decrease 0.35 ml%, 95% CI: 0.21% to 0.45%) with the SCD and no change with the Venodyne (median decrease 0.09 ml%, 95% CI: −0.25% to 0.22%). Conclusion: We conclude that sequential intermittent pneumatic compression of the calf and thigh is less likely to cause distal blood trapping and foot swelling than single-chamber calf compression. </jats:sec

Is the ‘Normal’ Limb Normal in Unilateral Varicose Veins?

Objective: To define venous function in the clinically normal limb of patients with unilateral primary varicose veins. Design: Prospective study using duplex scanning and photoplethysmography (PPG) as objective criteria of venous function. Setting: The Middlesex Hospital Vascular Laboratory, a teaching hospital centre of referral for the investigation of venous disease. Patients: Thirty patients with clinical unilateral primary varicose veins. Results: All clinically abnormal limbs had abnormalities on investigation. However, four of 30 patients (13%) also had abnormal duplex findings on the contralateral clinically normal limb, and six (20%) had abnormal PPG refilling times. A total of 26% clinically normal limbs could be demonstrated to have some abnormality of venous function using these two tests. Conclusions: We have shown that the contralateral, clinically normal limb cannot be assumed to be normal without full formal venous assessment. </jats:sec

Integrated Care Pathways for Vascular Surgery

AbstractObjectives: a trial of the use of integrated care pathways (ICPs) for elective vascular surgical procedures. Design: a 12-month prospective study, following a multi-disciplinary group construction of current “best practice” ICPs, with changes in practice only occurring following careful audit of results. Materials: patients admitted to a single vascular unit for “open” repair of abdominal aortic aneurysm, carotid endarterectomy or femoropopliteal bypass grafting. Methods: patients followed ICPs on a daily basis with signatures required to confirm that action had been taken and careful recording of variances from the ICPs. Audit of variance data allowed changes in the ICPs and, hence, provision of the best possible nursing and clinical practice. Results: ICPs were well received by patients and staff. They improved communication, promoted an appreciation of each health group's role in patient care, increased nursing autonomy, reduced calls to junior medical staff, improved patient education and confidence and caused a marked reduction in hospital “length of stay”. Conclusions: ICPs have clear benefits. This study realises that benefits might be maximal for high throughput, high-cost procedures. Successful use of ICPs depends upon “clinical champions” and effective project management. Sufficient resource and training are essential