Measuring In-Vivo Foot Perfusion Distal to a Near-Circumferential Negative Pressure Wound Therapy Dressing via Thermal Imaging.

Background Negative pressure wound therapy (NPWT) has been shown to promote the healing of acute and chronic wounds. In our previous study, we demonstrated that a near-circumferential NPWT dressing provided "lift-off" on an in-vitro extremity model resulting in decreased pressure. We hypothesized that this decrease in pressure may increase perfusion distal to the NPWT dressing by increasing lymphatic drainage and venous flow. Methods In this study, we tested if a near-circumferential NPWT dressing caused any appreciable skin movement around the dressing. We then used a thermal imaging camera to test if there was an increase in perfusion to the foot when a near-circumferential NPWT dressing was placed around the lower leg and tested at various negative pressures. Finally, we wanted to see if an artificial "lift-off" mechanism would lead to an increase in perfusion. Results The skin was noted to stretch between the short ends of the NPWT dressing, consistent with our previously described "lift-off" mechanism. However, there was no correlation between negative pressure and perfusion to the foot in the other experiments. Conclusion This study demonstrated that a near-circumferential NPWT dressing may not have any appreciable effects on perfusion when applied on a healthy patient, however, future studies are needed to determine if similar results would be seen on a traumatized or otherwise compromised extremity.

An In Vitro Study Measuring the Effects of Circumferential and Near-Circumferential Closed Incisional Negative Pressure Wound Therapy Dressings.

Background Negative pressure wound therapy (NPWT) and closed incisional negative pressure wound therapy (ciNPWT) have been shown to promote the healing of acute and chronic wounds. Despite the growth in their usage, the mechanism by which they promote healing is not fully understood. Several studies have shown that NPWT results in a combination of microdeformation and macrodeformation, which may promote wound recovery. The macrodeformation forces have raised concerns about circumferential NPWT compressing the extremity and decreasing perfusion distal to the NPWT. The literature on circumferential NPWT is mixed, with some studies showing increased perfusion, while others have shown decreased perfusion. We hypothesized that a near-circumferential ciNPWT dressing applied over intact skin would provide a "lift-off" force rather than a compressive force. We also theorized that as the sponge contracts under negative pressure while in a near-circumferential setting, the dressing will pull on the surrounding skin and tissue, leading to a decrease in the pressure of the extremity. This could potentially translate to improved venous and lymphatic return, increasing perfusion to the tissue beneath the sponge as well as distal to the sponge. Methods This study consisted of three separate experiments. The first experiment measured the width and length of a ciNPWT dressing at various negative pressures. The second experiment utilized an in vitro model consisting of an elastic ball and tubing to examine the effects that circumferential and near-circumferential ciNPWT dressings may have on extremity pressure. Varying lengths of ciNPWT dressings were applied to the ball, ranging from 25% circumferential to 100% circumferential. The pressure within the ball was monitored as varying lengths of circumferential dressings were applied at various negative pressures. The third experiment utilized the same model as the second experiment but with a 66% circumferential dressing and various baseline ball pressures to see how extremity pressure may impact the ability of the ciNPWT dressing to alter extremity pressure. Results The first experiment demonstrated that a ciNPWT dressing decreased in length and width in a linear fashion as negative pressure was applied. The second experiment revealed that both fully circumferential and near-circumferential dressings resulted in a decrease in the pressure of the elastic ball at lower levels of suction. The greatest decrease in ball pressure was noted with the 66% near-circumferential dressing. With greater suction, however, the pressure within the ball was noted to increase above baseline. The third experiment illustrated that as the baseline pressure of a ball was increased, the dressing had less of an ability to change the pressure of the ball. Conclusions These results suggest that near-circumferential and circumferential ciNPWT systems may decrease the pressure of an extremity at certain negative pressures and that compression may be less likely to occur when used on a higher-pressure extremity.

Closed Incision Negative Pressure Wound Therapy in the Management of a Complex Fasciotomy Wound in a Pediatric Patient.

Acute compartment syndrome (ACS) is a known entity that most often occurs in the setting of trauma in both adult and pediatric patients. Fasciotomy remains the gold standard treatment for relieving intracompartmental pressures but is associated with significant complications. Significant variability exists regarding fasciotomy wound management and closure. We present the only known case report on use of circumferentially applied negative pressure wound therapy instill and dwell (NPWTi-d) followed by circumferentially applied closed incision negative pressure wound therapy (ciNPWT) for the soft tissue management of delayed ACS in a pediatric patient.

Circumferential Negative Pressure Wound Therapy with Instillation and Dwell Prior to Delayed Flap Coverage for a Type IIIB Open Tibia Fracture.

Gustilo and Anderson type IIIB open tibia fractures are associated with high rates of surgical site infection, wound complications, and flap failure. Controversy surrounds the optimal timing and method of wound management prior to flap coverage. No studies to date have investigated the use of negative pressure wound therapy with instillation and dwell for open type IIIB tibia fractures. We present a single case of an open type IIIB tibia fracture that was managed with 21 days of circumferentially applied negative pressure wound therapy with instillation and dwell prior to flap coverage. Our results suggest that negative pressure wound therapy with instillation and dwell may minimize infection risk, decrease wound size, and allow for delayed soft tissue coverage.

External fixation of pediatric femur fractures with cortical contact.

The cases of 40 pediatric femur fractures treated with external fixation were reviewed to determine whether stabilization with cortical contact resulted in clinical leg-length discrepancy (LLD). Mean follow-up was 29.4 months, mean age was 6.6 years (range, 2-10 years), 25 injuries were isolated, 100% of the fixators were applied with cortical contact, all fractures healed by a mean of 92 days, 72.5% were dynamized before removal, mean LLD was 0.24 cm short, and complications included 1 refracture (2.5%), early removal of 2 loose pins (1.25% of 160 pins), pin-tract infections in 21 patients (52.5%), and 1 LLD (2.5%) of more than 1.0 cm (5.0 cm short). External fixation with cortical contact was an effective treatment for pediatric femur fractures. It limited overgrowth and resulted in few refractures. Pin-tract infections were common.

Efficacy of cephalexin two vs. three times daily vs. cefadroxil once daily for streptococcal tonsillopharyngitis.

The purpose of this study was to compare the bacteriologic and clinical efficacy of oral cephalexin twice vs. three times daily vs. cefadroxil once daily as therapy for group A beta-hemolytic streptococcal (GABHS) tonsillopharyngitis. A prospective open-label, observational cohort study was conducted over 18 months (January 2000-June 2001). Children enrolled had an acute onset of symptoms and signs of a tonsillopharyngeal illness and a laboratory-documented GABHS infection. Follow-up examination and laboratory testing occurred 21 +/- 4 days following enrollment. Two hundred seventy-one patients were enrolled (intent to treat group): 63 received cephalexin twice daily, 124 received cephalexin three times daily, and 84 received cefadroxil once daily. Fifty-three children did not return for the follow-up visit, leaving 218 patients in the per-protocol group: 54 cephalexin twice-daily treated, 94 cephalexin 3-times daily treated, and 70 cefadroxil once-daily treated. In the per-protocol group, bacteriologic cure for those treated with cephalexin twice daily was 87%, for cephalexin 3 times daily, it was 81% and for cefadroxil once daily it was 81% (p = 0.61). The clinical cure rate for cephalexin twice-daily treatment was 91%; for three-times daily, it was 86%; and for cefadroxil once daily, it was 84% (p = 0.56). Because treatment allocation was not randomized, logistic regression analysis was used to adjust for treatment group differences. Younger age of patient was significantly associated with bacteriologic (p = 0.04) and clinical (p = 0.01) failure independent of treatment group but in the adjusted logistic model no differences were found among the 3 treatment regimens. Cephalexin dosed twice daily or three times daily and cefadroxil dosed once daily appear equivalent in bacteriologic and clinical cure of GABHS tonsillopharyngitis.

Efficacy of penicillin vs. amoxicillin in children with group A beta hemolytic streptococcal tonsillopharyngitis.

The purpose of this study was to compare the bacteriologic and clinical efficacy of oral penicillin versus amoxicillin as first-line therapy for group A beta-hemolytic streptococcal (GABHS) tonsillopharyngitis. The prospective observational study was conducted over 18 months (January 2000-June 2001). Children enrolled had acute onset of symptoms and signs and a laboratory-documented GABHS tonsillopharyngitis illness. Follow-up examination and laboratory testing occurred 10 +/- 4 days following completion of treatment. In total, 389 patients were enrolled (intent-to-treat group): 195 received penicillin V and 194 received amoxicillin. Fifty-six of the penicillin-treated and 57 amoxicillin-treated patients refused to take the drug, or were noncompliant, or did not return for the follow-up visit, leaving 276 patients in the per-protocol group: 139 penicillin-treated and 137 amoxicillin-treated. Bacteriologic cure for amoxicillin-treated children occurred in 76% versus 64% in the penicillin-treated children (p = 0.04). The clinical cure rate for amoxicillin-treated children was 84% compared to 73% in the penicillin-treated children (p = 0.03). Since treatment allocation was not randomized, logistic regression analysis was used to adjust for treatment group differences. The odds ratio (OR) estimate for cure for patients in the amoxicillin versus penicillin V treatment group remained significant (OR = 1.84, 95% confidence interval 1.02-3.29); the same was true for dinical cure (OR = 1.99, 95% CI = 1.02-3.87). Amoxicillin may be superior to penicillin for bacteriologic and clinical cure of GABHS tonsillopharyngitis.