Intermittent Negative Pressure Research Articles

Flap Preconditioning by Intermittent Negative Pressure

Flap Preconditioning by Intermittent Negative Pressure

The effects of lower limb intermittent negative pressure therapy on the skin microcirculation perfusion of quadriceps in male rowers

To investigate the effects of intermittent negative pressure therapy on the skin microcirculation perfusion of quadriceps in male rowers, and to provide basis for the practical application of this method. Fourteen male rowers were selected from the national rowing team and randomly divided into experimental and control groups. The daily training plans of two groups were the same. The recovery intervention for experimental group was implemented by 20 minutes in the cube of Vacusport Regeneration System (German), 5 times per week for 4 weeks, no recovery intervention for control group. Microcirculation markers were collected by PeriFlux5000 system before and after the 4-week intervention. The markers included microcirculatory blood perfusion(MBP), average velocity of blood cells(AVBC), concentration of moving blood cells (CMBC), and values of the markers included basic values and post-heating values (44℃), difference before and after heating of the values was considered as the reserve capacity of those markers. The test results before the 4 weeks intervention showed there was no statistical difference between the two groups(P＞0.05). After the 4 weeks intervention: ①MBP: The post-heating value and the difference of the experimental group were significantly higher than those of the control group (P＜0.05). But there was no statistical inner-group difference. ②AVBC: The post-heating values and the difference in the experimental group were significantly lower than those in the control group (P＜0.05). Intra-group comparison found that the post-heating values after post-intervention were significantly reduced, compared with those of pre-intervention (P＜ 0.01); the difference after post-intervention was reduced significantly, compared with those in the pre-intervention (P＜0.05). ③CMBC: The post-heating values and the difference in the experimental group were significantly higher than those in the control group (P＜0.01). There were no statistical significant inner-group difference. Lower limb intermittent negative pressure therapy can improve the skin microcirculation of the quadriceps of the male rowers, which has a positive effect on the rapid recovery of physical fitness.

A novel intermittent negative air pressure device ameliorates obstructive sleep apnea syndrome in adults.

Patients with obstructive sleep apnea syndrome (OSAS) have difficulties in compliance with continuous positive airway pressure (CPAP) and the treatment outcome is heterogeneous. We proposed a proof-of-concept study of a novel intermittent negative air pressure (iNAP®) device for physicians to apply on patients who have failed or refused to use CPAP. The iNAP® device retains the tongue and the soft palate in a forward position to decrease airway obstruction. A full nightly usage with the device was evaluated with polysomnography. Subgrouping by baseline apnea-hypopnea index (AHI) and body mass index (BMI) with different treatment response criteria was applied to characterize the responder group of this novel device. Thirty-five patients were enrolled: age 41.9 ± 12.2years (mean ± standard deviation), BMI 26.6 ± 4.3kg/m2, AHI 41.4 ± 24.3 events/h, and oxygen desaturation index (ODI) 40.9 ± 24.4 events/h at baseline. AHI and ODI were significantly decreased (p < 0.001) by the device. Patients with moderate OSAS, with baseline AHI between 15 to 30 events/h, achieved 64% response rate; and non-obese patients, with BMI below 25kg/m2, achieved 57% response rate, with response rate defined as 50% reduction in AHI from baseline and treated AHI lower than 20. There were minimal side effects reported. In a proof-of-concept study, the device attained response to treatment as defined, in more than half of the moderate and non-obese OSAS patients, with minimal side effects.

Continuous peritoneal lavage with vacuum peritoneostomy: an experimental study

OBJECTIVE:Despite advances in diffuse peritonitis treatment protocols, some cases develop unfavorably. With the advent of vacuum therapy, the use of laparostomy to treat peritonitis has gained traction. Another treatment modality is continuous peritoneal lavage. However, maintaining this technique is difficult and has been associated with controversial results. We propose a new model of continuous peritoneal lavage that takes advantage of the features and benefits of vacuum laparostomy.METHOD:Pigs (Landrace and Large White) under general anesthesia were submitted to laparostomy through which a multiperforated tube was placed along each flank and exteriorized in the left and lower right quadrants. A vacuum dressing was applied, and intermittent negative pressure was maintained. Peritoneal dialysis solution (PDS) was then infused through the tubes for 36 hours. The stability of peritoneostomy with intermittent infusion of fluids, the system resistance to obstruction and leakage, water balance, hemodynamic and biochemical parameters were evaluated. Fluid disposition in the abdominal cavity was analyzed through CT.RESULTS:Even when negative pressure was not applied, the dressing maintained the integrity of the system, and there were no leaks or blockage of the catheters during the procedure. The aspirated volume by vacuum laparostomy was similar to the infused volume (9073.5±1496.35 mL versus 10165±235.73 mL, p=0.25), and there were no major changes in hemodynamic or biochemical analysis. According to CT images, 60 ml/kg PDS was sufficient to occupy all intra-abdominal spaces.CONCLUSION:Continuous peritoneal lavage with negative pressure proved to be technically possible and may be an option in the treatment of diffuse peritonitis.

PO-097 The effect of 4 weeks intermittent negative pressure treatment on the functional state of excellent rowers

Objective To study the effect of intermittent negative pressure treatment on the functional state of elite rowers ,and providing theoretical basis for the application of this method in sports science.&#x0D; Methods The 15 elite male athletes selected from the national rowing training team were divided into experimental group and control group. The daily training plans of the two groups were the same. The members of experimental group were treated for 20 minutes by the Vacusport Regeneration System from German, five times one week, for a total of 4-weeks. The control group did not use any intervention. Before and after 4 weeks, venous blood from 15 male athletes was used to test athletes 'red blood cells(RBC), hemoglobin(HGB), hematocrit (HCT), creatine kinase(CK), blood urea nitrogen(BU), testosterone(T), cortisol(C) et, Observing the changes about data from two tests.&#x0D; Results There was no statistically significant difference between the experimental group and the control group before and after the intervention. The results of the intra-group comparison were as follows:(1) The RBC, HGB, and HCT of the experimental group decreased by 2.90 %, 3.80 %, and 1.08 % respectively. The RBC, HGB, and HCT of the control group decreased by 6.55 %, 7.02%, 4.03% respectively, and the decline of RBC and HGB showed statistically significant changes(p&lt;0.05).（2）The CK and BU values of the experimental group increased by 1.26 % and 27.08 % respectively, and the increase of BU had statistically significant changes(p&lt;0.05). The CK and BU values of the control group increased by 33.10 % and 9.54 % respectively. (3) The values of T, C and T / C in experimental group decreased by 11.85 %, 7.6 % and 4.31 % respectively. The values of T, C and T / C in the control group decreased by 16.38 %, 4.03 % and 19.39 % respectively, and the decrease of T values was statistically significant(p&lt;0.05).&#x0D; Conclusions The intermittent negative pressure therapy can promote the athletes' metabolism, relieve the degree of the decline of functional state, and prevent the occurrence of fatigue.

Improvement of local microcirculation through intermittent Negative Pressure Wound Therapy (NPWT)

BackgroundNegative Pressure Wound Therapy (NPWT) is widely used across different kinds of surgical disciplines. A controversial debate was raised by diverging results from studies that were conducted to examine the impact of NPWT on local perfusion. Thus, there is a lack of evidence for one important underlying factors that influences the physiology of wound healing under an applied NPWT-dressing. ObjectiveTo investigate the immediate local perfusion changes due to an applied intermittent NPWT protocol. Material and methodsA NPWT dressing was applied to the antero-lateral thigh of seven healthy volunteers with two probes of both pressure and microcirculatory measuring devices. One of each probe was placed under the NPWT dressing, the other one in close proximity next to it. A protocol consisting of two cycles of 10 min of −125 mmHg pressure, followed by 10 min of 0 mmHg pressure was applied. Measurements of local pressure to the underlying tissue, as well as microcirculatory changes were performed continuously. ResultsApplied vacuum caused compressional forces (27.33 mmHg, p < 0.05) towards the underlying tissue. Blood Flow was increased after both suction periods (+52.5%, +108.7%; p < 0.05) and continued increasing until the end of measurements (+145.3%). This was accompanied by significant increase in Oxygen Saturation (+21.6%; p < 0.05) and Relative Hemoglobin Content (+16.7%). Red Blood Cell Velocity was found to be increased without statistical significance. Next to the dressing, changes were also significant but less pronounced. ConclusionIntermittent NPWT improves local microcirculation with consecutive enhancement of oxygen supply.

Intermittent mild negative pressure applied to the lower limb in patients with spinal cord injury and chronic lower limb ulcers: a crossover pilot study.

Randomized, assessor-blinded crossover pilot study. To explore the use of an intermittent negative pressure (INP) device for home use in addition to standard wound care (SWC) for patients with spinal cord injury (SCI) and chronic leg and foot ulcers before conducting a superiority trial. Patient homes and outpatient clinic. A 16-week crossover trial on 9 SCI patients (median age: 57 years, interquartile range [IQR] 52-66), with leg ulcers for 52 of weeks (IQR: 12-82) duration. At baseline, patients were allocated to treatment with INP + SWC or SWC alone. After 8 weeks, the ulcers were evaluated. To assess protocol adherence, the patients were then crossed over to the other group and were evaluated again after another 8 weeks. Lower limb INP treatment consisted of an airtight pressure chamber connected to an INP generator (alternating 10 s -40mmHg/7 s atmospheric pressure) used 2 h/day at home. Ulcer healing was assessed using a photographic wound assessment tool (PWAT) and by measuring changes in wound surface area (WSA). Seven of nine recruited patients adhered to a median of 90% (IQR: 80-96) of the prescribed 8-week INP-protocol, and completed the study without side effects. PWAT improvement was observed in 4/4 patients for INP + SWC vs. 2/5 patients for SWC alone (P = 0.13). WSA improved in 3/4 patients allocated to INP + SWC vs. 3/5 patients in SWC alone (P = 0.72). INP can be used as a home-based treatment for patients with SCI, and its efficacy should be tested in an adequately sized, preferably multicenter randomized trial.

P798Application of intermittent negative upper airway pressure as a novel rat model for obstructive sleep apnea and atrial fibrillation

P798Application of intermittent negative upper airway pressure as a novel rat model for obstructive sleep apnea and atrial fibrillation

Negative pressure wound therapy for chronic venous ulcer: a randomized-controlled study

Objective The purpose of this study was to evaluate the efficacy of negative pressure wound therapy (NPWT) in promoting wound healing of venous leg ulceration. Patients and methods This study was designed as a single-center randomized-controlled trial. Patients with venous leg ulcer of at least 3 months in duration were enrolled in this study. The first group (NPWT group) was treated by NPWT using standardized method. Intermittent negative pressure at −100 to −150 mmHg was applied, and the dressings were changed every 48–72 h. The second group (control group) was treated by conventional daily dressing using normal saline. Results After 15 days of treatment, significant differences in ulcer size and percent of ulcer healing were detected between the two treatment groups. The wound healing rate was 13.1 and 2.8 mm2/day in NPWT group and control group, respectively. After 30 days of treatment, 17 (68%) ulcers revealed 90% healing in NPWT group, with mean duration of 24 days needed for healing. None of the ulcers in control group completed 90% healing after the 30 days of treatment. Conclusion NPWT improved wound healing and may be considered as treatment for venous leg ulcer.

Treatment of early chronic infections with tumor prosthesis by intermittent negative pressure wound therapy with instillation

Treatment of early chronic infections with tumor prosthesis by intermittent negative pressure wound therapy with instillation

Intermittent negative pressure applied to the lower limb increases foot macrocirculatory and microcirculatory blood flow pulsatility in people with spinal cord injury.

Experimental prestudy and poststudy. Examine the acute effects of intermittent negative pressure (INP) applied to the lower limb on foot circulation in people with spinal cord injuries (SCIs). Vascular laboratory, Oslo University Hospital. Twenty-four people with SCI (median age 59 years, range 29-74) were exposed to lower leg INP (-40 mm Hg) using an air-tight pressure chamber connected to an INP generator. The contralateral leg was placed outside the pressure chamber. We continuously measured arterial blood flow velocity (ultrasound Doppler), skin blood flow (laser Doppler), skin temperature of the dorsum of the foot, heart rate (ECG) and systemic blood pressure (Finometer) during 5-min baseline (atmospheric pressure), followed by 10-min INP (alternating 10 s -40 mm Hg and 7 s atmospheric pressure), and 5-min post-INP (atmospheric pressure). Skin blood flow was measured on the foot placed outside the pressure chamber. A mixed effects regression model was applied to estimate the effect of INP on blood flow. To quantify flow fluctuations, we calculated cumulative up-and-down changes in arterial blood flow velocity per minute. Flow fluctuations increased during INP compared to baseline [32.3 cm/s/min (95% CI 26.9 to 37.7) vs. 15.2 cm/s/min (95% CI 9.8 to 20.6), P < 0.001]. Peak blood flow velocity and skin blood flow was reached 2-3 s after the onset of negative pressure and increased 33% (95% CI 16 to 46, P < 0.001) and 11% (95% CI -4.1 to 60, P = 0.14) above baseline, respectively. INP induced increased foot arterial blood flow fluctuations compared to baseline. The Norwegian Research Council provided funding to Otivio (grant: 241589).

Effect of intermittent negative pressure on matrix metalloproteinase 9 and transforming growth factor β of tendon-bone interface and joint fluid after reconstruction of anterior cruciate ligament in rabbits

Objective: To study the effect of intermittent negative pressure on matrix metalloproteinase 9 (MMP)-9 and transforming growth factor β of tendon-bone interface and joint fluid after reconstruction of anterior cruciate ligament in rabbits. Methods: A total of twenty-four New Zealand white rabbits were randomly selected hind leg of negative group, contralateral hind leg as control.Reconstruction of the anterior cruciate ligament was done by autogenous semitendinosus of rabbit.Joint of the negative pressure side placed drainage tube connecting the micro-negative pressure aspirator, and maintained an intermittent, low-intensity negative pressure.Control side placed ordinary drainage tube.Drainage tube of both sides was pulled out at the same time after 5 days.After 6 weeks, joint fluid and femur-ligament-tibia complex were obtained for study of expression of MMP-9 and TGF-β in joint fluid and tendon-bone interface. Result: Twenty-three rabbits were included in the study because of one rabbit joint infections.Detection of joint fluid showed that MMP-9 content is significantly lower in negative group than that in the control group, and the difference is statistically significant [(8.9±1.3) pg/L vs (12.3±1.8) pg/L (P=0.002)]. TGF-β content is significantly higher in negative group in joint fluid than that in the control group, and the difference is statistically significant [(19.0±2.2) pg/L vs (15.2±1.4) pg/L (P=0.000)]. Study of immunohistochemistry in tendon-bone interface found that expression of MMP-9 is lower in negative pressure group than that in the control group, and the difference is statistically significant (P=0.000). TGF-β expression is significantly higher in negative group in tendon-bone interface than that in the control group, and the difference is statistically significant (P=0.000). Conclusion: Intermittent negative pressure may reduce content of MMP-9 in joint fluid and expression of MMP-9 in tendon-bone interface, increase content of TGF-β in joint fluid and expression of TGF-β in tendon-bone interface after reconstruction of anterior cruciate ligament in rabbits.

Moderate intermittent negative pressure increases invasiveness of MDA-MB-231 triple negative breast cancer cells

BackgroundTo investigate the effect moderate intermittent negative pressure breast reconstructive model exerts on human triple negative breast cancer cell (TNBC) invasion and explore the related mechanism. MethodsThe human TNBC cell line MDA-MB-231 was used. Cells in external volume expansion (EVE) group were exposed to an intermittent −25 mmHg for 12 h; the pressure for non-EVE group was constantly 0 mmHg. In vivo, MDA-MB-231 cell suspensions were injected subcutaneously into dorsal skin of nude mice (n = 27 mice/group). Tumors on mice in EVE group received −25 mmHg suction 3 h/day; while mice in non-EVE group were under normal pressure. Cell invasion assay, ELISA, RT-PCR, western blot analysis and immunohistochemistry were used to evaluate the inflammation, epithelial-mesenchymal transition (EMT) and angiogenesis between the two groups in both vitro and vivo experiments. ResultsMDA-MB-231 cells in the EVE group were more invasive and had higher expressions of IL-8 (30.02 ± 10.44 pg/ml vs. 18.82 ± 9.26 pg/ml, P < 0.05) and TNF-α (20.59 ± 4.72 pg/ml vs. 14.10 ± 3.36 pg/ml, P < 0.05) than the non-EVE group. Grafted MDA-MB-231 tumors in EVE group showed a more obvious epithelial-mesenchymal transition at 2 week and better angiogenesis at 2 and 4 week, respectively. ConclusionModerate intermittent negative pressure induces MDA-MB-231 cells to be more invasive. Future studies should figure out other effects this intervention may bring. Clinical studies should also be conducted to further evaluate its safety and optimize the clinical model.

Methods and values of suction drainage following secondary total ear reconstruction with an expanded post-auricular marsupial flap

Objective To discuss continuous negative pressure suction and different negative pressure monitoring after the external ear reconstruction operation stage Ⅱ, aiming to improve the security of the plastic surgery. Methods A lot of 87 microtia patients aged 6-15 years were randomly selected as control group from Feb. 2010 to Mar. 2012, and other 87 cases of microtia were also randomed as experimental group from Apr. 2012 to Apr. 2014. The experimental group adopted the continuous negative pressure suction and the pressure value was set as 3.99-5.32 kPa (30-40 mmHg); the control group adopted the method of traditional intermittent negative pressure drainage and the suction pressure was set as 3.99-7.98 kPa (30-60 mmHg). After the operation, the two groups were observed and compared under continuous negative pressure suction. The capacity, color changes, length of time, and pressure value of the drain were monitored and observed, finding out their correlation with the operation effectiveness. Results For the experimental group, the incidence of subcutaneous hydrops and skin flap necrosis was lower (P<0.05), and the primary healing rate was higher than the control group (P<0.01). The capacity of drain was relevant to the type of the plastic surgery, different from 5 to 20 ml; the color changed gradually from blood color to faint yellow; the extubation time was generally from 7 to 10 days. The optimal pressure value was 3.99-5.32 kPa (30-40 mmHg); there was proportional relation between the effectiveness of monitoring drainage and the operation effectiveness. Conclusions Continuous negative pressure suction monitoring after operation contributes to improve the plastic surgery effectiveness, and the patients are satisfied with the result. Key words: Negative pressure drainage; Marsupial skin flap; Expansion

The acute effects of lower limb intermittent negative pressure on foot macro- and microcirculation in patients with peripheral arterial disease.

BackgroundIntermittent negative pressure (INP) applied to the lower leg and foot increases foot perfusion in healthy volunteers. The aim of the present study was to describe the effects of INP to the lower leg and foot on foot macro- and microcirculation in patients with lower extremity peripheral arterial disease (PAD).MethodsIn this experimental study, we analyzed foot circulation during INP in 20 patients [median (range): 75 (63-84yrs)] with PAD. One leg was placed inside an air-tight vacuum chamber connected to an INP-generator. During application of INP (alternating 10s of -40mmHg/7s of atmospheric pressure), we continuously recorded blood flow velocity in a distal foot artery (ultrasound Doppler), skin blood flow on the pulp of the first toes (laser Doppler), heart rate (ECG), and systemic blood pressure (Finometer). After a 5-min baseline sequence (no pressure), a 10-min INP sequence was applied, followed by 5-min post-INP (no pressure). To compare and quantify blood flow fluctuations between sequences, we calculated cumulative up-and-down fluctuations in arterial blood flow velocity per minute.ResultsOnset of INP induced an increase in arterial flow velocity and skin blood flow. Peak blood flow velocity was reached 3s after the onset of negative pressure, and increased 46% [(95% CI 36–57), P<0.001] above baseline. Peak skin blood flow was reached 2s after the onset of negative pressure, and increased 89% (95% CI 48–130), P<0.001) above baseline. Cumulative fluctuations per minute were significantly higher during INP-sequences compared to baseline [21 (95% CI 12–30)cm/s/min to 41 (95% CI 32–51)cm/s/min, P<0.001]. Mean INP blood flow velocity increased significantly ~12% above mean baseline blood flow velocity [(6.7 (95% CI 5.2–8.3)cm/s to 7.5 (95% CI 5.9–9.1)cm/s, P = 0.03)].ConclusionINP increases foot macro- and microcirculatory flow pulsatility in patients with PAD. Additionally, application of INP resulted in increased mean arterial blood flow velocity.

Application of intermittent negative pressure on the lower extremity and its effect on macro- and microcirculation in the foot of healthy volunteers.

Intermittent negative pressure (INP) applied to the lower leg and foot may increase peripheral circulation. However, it is not clear how different patterns of INP affect macro‐ and microcirculation in the foot. The aim of this study was therefore to determine the effect of different patterns of negative pressure on foot perfusion in healthy volunteers. We hypothesized that short periods with INP would elicit an increase in foot perfusion compared to no negative pressure. In 23 healthy volunteers, we continuously recorded blood flow velocity in a distal foot artery, skin blood flow, heart rate, and blood pressure during application of different patterns of negative pressure (−40 mmHg) to the lower leg. Each participant had their right leg inside an airtight chamber connected to an INP generator. After a baseline period at atmospheric pressure, we applied four different 120 sec sequences with either constant negative pressure or different INP patterns, in a randomized order. The results showed corresponding fluctuations in blood flow velocity and skin blood flow throughout the INP sequences. Blood flow velocity reached a maximum at 4 sec after the onset of negative pressure (average 44% increase above baseline, P < 0.001). Skin blood flow and skin temperature increased during all INP sequences (P < 0.001). During constant negative pressure, average blood flow velocity, skin blood flow, and skin temperature decreased (P < 0.001). In conclusion, we observed increased foot perfusion in healthy volunteers after the application of INP on the lower limb.

The effectiveness of dry-cupping in preventing post-operative nausea and vomiting by P6 acupoint stimulation: A randomized controlled trial.

Background:Postoperative nausea and vomiting (PONV) is a common complication after general anesthesia, and the prevalence ranges between 25% and 30%. The aim of this study was to determine the preventive effects of dry cupping on PONV by stimulating point P6 in the wrist.Methods:This was a randomized controlled trial conducted at the Imam Reza Hospital in Kermanshah, Iran. The final study sample included 206 patients (107 experimental and 99 controls). Inclusion criteria included the following: female sex; age>18 years; ASA Class I-II; type of surgery: laparoscopic cholecystectomy; type of anesthesia: general anesthesia. Exclusion criteria included: change in the type of surgery, that is, from laparoscopic cholecystectomy to laparotomy, and ASA-classification III or more. Interventions are as follows: pre surgery, before the induction of anesthesia, the experimental group received dry cupping on point P6 of the dominant hand's wrist with activation of intermittent negative pressure. The sham group received cupping without activation of negative pressure at the same point. Main outcome was that the visual analogue scale was used to measure the severity of PONV.Results:The experimental group who received dry cupping had significantly lower levels of PONV severity after surgery (P < 0.001) than the control group. The differences in measure were maintained after controlling for age and ASA in regression models (P < 0.01).Conclusion:Traditional dry cupping delivered in an operation room setting prevented PONV in laparoscopic cholecystectomy patients.

Intermittent negative pressure wound therapy with instillation for the treatment of persistent periprosthetic hip infections: a report of two cases.

Intermittent negative pressure wound therapy with instillation (NPWTi) is starting to be used successfully to treat early periprosthetic infections of endoprostheses. However, few articles have reported the outcome of treatment with intermittent NPWTi for late persistent periprosthetic infections of the hip. In this study, we report two cases who underwent several rounds of radical wound debridement for the treatment of a late persistent periprosthetic infection of the hip. Intermittent NPWTi was used in both cases. Patients were treated successfully and there was no recurrence after 3 and 1 years of follow-up, respectively.

The Use of Negative Pressure Wave Treatment in Athlete Recovery

Lower body negative pressure (LBNP) treatment was developed for astronauts in order to maintain the arterial blood supply of the lower body and compensate for weightlessness. In clinical applications the use of negative pressure has proven substantial in treatment of general soft-tissue injuries, open fractures, and management of diabetic and pressure ulcers. In competitive sport, regeneration and recovery of athletes play a vital role to maximise their performance. PURPOSE: Validation of the LBNP device by assessing if intermittent negative pressure therapy applied to the lower body of athletes has a systemic effect resulting in faster recovery time. METHODS: A random designed cross-over study with repeated measures was performed. Healthy male cricket players (n=22), aged 18-22 years continued to follow their weekly regular physical training program (7 hours conditioning and 10 hours cricket specific skills, with one competitive match on weekends), for the duration of the study. Additionally they were subjected to an intense and structured 1 hour exercise training program and power gym session on the day treatment started. Players were exposed to one 30 minute LBNP treatment session for three consecutive days (i.e. at 0, 24 and 48 hours). Heart rate, blood pressure, blood serum lactate and -creatine kinase (CK) were measured. RESULTS: During treatment sessions the heart rate and blood pressure decreased drastically but reverted back to baseline levels within an hour. Using the repeated measures ANOVA test, the lactate concentration did not show an individual (p=0.41) nor a period effect (p=0.11). In the group effect the lactate decreased significantly (p=0.008) after termination of exercise. The ratio of the period directly after training vs. the period directly after treatment was analysed. The LBNP device resulted in lowering lactate measurements significantly (control group 0.868; treatment group 0.575). ANOVA analysis of CK did not indicate a significant decrease after 3 treatment sessions. The CK concentration ratio after the third therapy session vs. after the first therapy session did not significantly decrease. CONCLUSION: LBNP therapy seems to have a systemic effect in lowering serum lactate levels, but not CK levels. Enhanced regeneration and recovery of athletes are still unconfirmed.

Histopathological study of chronic wounds modulated by intermittent negative pressure therapy under limited access dressing

Aim: Negative pressure wound therapy (NPWT) has achieved widespread success in the treatment of chronic wounds. However, its effects have been only partially explored, and investigations have generally concentrated on the wound-dressing interface; a detailed histopathological description of the evolution of wounds under NPWT is still lacking. The present study was performed to investigate the effect of a limited access dressing (LAD) which exerts intermittent NPWT in a moist environment on chronic wounds. Methods: A total of 140 patients were randomized into 2 groups: LAD group ( n = 64) and conventional dressing group ( n = 76). By histopathological analysis of the granulation tissue, the amount of inflammatory infiltrate, necrotic tissue, angiogenesis, and extracellular matrix (ECM) deposition was studied and compared to determine healing between the 2 groups. Results: After 10 days of treatment, histopathological analysis showed a significant decrease in necrotic tissue with LAD compared to the conventional dressing group (mean ± standard error, 11.5 ± 0.48 vs . 10.1 ± 0.30, P = 0.007), the number of inflammatory cells (12.6 ± 0.60 vs . 8.63 ± 0.35, P = 0.018), a significant increase in new blood vessels (12.8 ± 0.58 vs . 9.3 ± 0.29, P = 0.005) and ECM deposit (13.3 ± 0.50 vs . 9.6 ± 0.24, P = 0.001). Conclusion: LAD exerts its beneficial effects on chronic wound healing by decreasing the amount of necrotic tissue and inflammatory cells while increasing the amount of ECM deposition and angiogenesis.