Incisional negative pressure wound therapy to reduce surgical-site infections in major limb amputations: a meta-analysis.

Purpose: Incisional negative pressure wound therapy (iNPWT) has shown effectiveness in the treatment of high-risk surgical wounds. Especially patients with diabetes-induced peripheral arterial disease undergoing major limb amputation have a high intrinsic risk for post-surgical wound infections. While normal gauze wound dressings do not cause stimulation of microvasculature, iNPWT might improve wound healing and reduce wound complications. The purpose of this study was to systematically review the literature for rates of wound complications and readmissions, as well as post-surgical 30-day mortality. Methods: We conducted a systematic review searching the Cochrane, PubMed, and Ovid databases. Inclusion criteria were the modified Coleman methodology Score >60, non-traumatic major limb amputation, and adult patients. Traumatic amputations and animal studies were excluded. Relevant articles were reviewed independently by referring to the title and abstract. In a meta-analysis, we compared 3 studies and 457 patients. Results: A significantly overall lower rate of postoperative complications is associated with usage of iNPWT (odds ratio (OR) = 0.52; 95% CI: 0.30-0.89; P = 0.02). There was no significant improvement for 30-day mortality, when iNPWT was used (OR= 081; 95% CI: 0.46 - 1.45; P = 0.48). Nevertheless, we did not note a significant difference in the readmission rate or revision surgery between the two groups. Conclusion: Overall, the usage of iNPWT may reduce the risk of postoperative wound complications in major lower limb amputations but does not improve 30-day mortality rates significantly. However, to anticipate surgical-site infection, iNPWT has shown effectiveness and thus should be used whenever applicable.

Laminar airflow decreases microbial air contamination compared with turbulent ventilated operating theatres during live total joint arthroplasty: a nationwide survey.

BACKGROUND: Preventing surgical site infections and prosthetic joint infections is crucial for patient safety after total joint arthroplasty. Microbial air contamination has been suggested as a risk factor. Therefore, the ventilation system that will reduce air contamination most effectively in operating theatres (OTs) has been discussed. AIM: To determine whether laminar airflow (LAF) ventilation is superior to turbulent airflow (TAF) ventilation by looking at the colony forming units (cfu) count during live total hip and knee arthroplasties. Furthermore, to explore whether the number of OT personnel, door and cabinet lock openings and technical parameters of the ventilation systems have an impact on the number of cfu. METHODS: Active air sampling and passive sedimented bacterial load were performed in 17 OTs, equipped with either LAF or TAF ventilation, during 51 live surgeries while observations were noted. FINDINGS: LAF OTs reduced cfu counts compared with TAF OTs during live surgery (P<0.001). All LAF OTs provided ultraclean air whereas TAF had nine procedures exceeding the threshold of 10 cfu/m3. Door and cabinet lock openings and number of personnel did not influence the cfu count, while it decreased with increasing volume and total air change per hour (P<0.05). CONCLUSION: All LAF OTs had cfu counts within recommendations and provided lower cfu counts compared with TAF OTs. The number of OT personnel and total openings did not have an influence on cfu counts. Increased volume of the OT and total air change per hour showed a decrease in active cfu counts.

The exceptional X-ray evolution of SN 1996cr in high resolution.

We present X-ray spectra spanning 18 yr of evolution for SN 1996cr, one of the five nearest SNe detected in the modern era. Chandra HETG exposures in 2000, 2004, and 2009 allow us to resolve spectrally the velocity profiles of Ne, Mg, Si, S, and Fe emission lines and monitor their evolution as tracers of the ejecta-circumstellar medium interaction. To explain the diversity of X-ray line profiles, we explore several possible geometrical models. Based on the highest signal-to-noise 2009 epoch, we find that a polar geometry with two distinct opening angle configurations and internal obscuration can successfully reproduce all of the observed line profiles. The best-fitting model consists of two plasma components: (1) a mildly absorbed (2 × 1021 cm-2), cooler (≈2 keV) with high Ne, Mg, Si, and S abundances associated with a wide polar interaction region (half-opening angle ≈58°); (2) a moderately absorbed (2 × 1022 cm-2), hotter (≳20 keV) plasma with high Fe abundances and strong internal obscuration associated with a narrow polar interaction region (half-opening angle ≈20°). We extend this model to seven further epochs with lower signal-to-noise ratio and/or lower spectral-resolution between 2000 and 2018, yielding several interesting trends in absorption, flux, geometry, and expansion velocity. We argue that the hotter and colder components are associated with reflected and forward shocks, respectively, at least at later epochs. We discuss the physical implications of our results and plausible explosion scenarios to understand the X-ray data of SN 1996cr.

Short time-frame from first to second hip fracture in the Funen County Hip Fracture Study.

INTRODUCTION: Hip fracture patients represent a frail group of elderly with increased morbidity and mortality. The aim of this study was to evaluate the occurrence and distribution of a second hip fracture in the time interval between the first and the second hip fracture. METHODS: All incident hip fractures in residents of Funen County, Denmark, from 1994 through 2004 were recorded. Verified fractures were sequenced within each patient using the unique Danish identification numbers. RESULTS: In total, 9990 incident hip fractures occurred: 9122 first hip fractures and 868 (8.7%) second fractures. Within the first year after the first hip fracture, the incidence rate of the second fracture in men decreased from 73 per 1000 person-years (py) during the first 3 months to 8 per 1000 py at 12 months; in women, it decreased from 116 per 1000 py during the first 3 months to 15 per 1000 py at 12 months. Of all the second fractures, 50% occurred within 12 months in men and within 19 months in women. CONCLUSIONS: Few hip fracture patients experience a second hip fracture and when they do, it is within a short time-frame from the first. The risk of sustaining a second hip fracture is high during the first 12 months following the first hip fracture, decreasing to a level equal to or below the incidence of the first hip fracture after this 12-month period. Preventive strategies at the time of the first hip fracture should therefore aim at immediate effects, as interventions with effects after 12 months (men) and 19 months (women) bypass at least 50% of the fractures.

Cardiovascular effects of epinephrine during rewarming from hypothermia in an intact animal model.

Rewarming from accidental hypothermia is often complicated by "rewarming shock," characterized by low cardiac output (CO) and a sudden fall in peripheral arterial pressure. In this study, we tested whether epinephrine (Epi) is able to prevent rewarming shock when given intravenously during rewarming from experimental hypothermia in doses tested to elevate CO and induce vasodilation, or lack of vasodilation, during normothermia. A rat model designed for circulatory studies during experimental hypothermia and rewarming was used. A total of six groups of animals were used: normothermic groups 1, 2, and 3 for dose-finding studies, and hypothermic groups 4, 5, and 6. At 20 and 24 degrees C during rewarming, group 4 (low-dose Epi) and group 5 (high-dose Epi) received bolus injections of 0.1 and 1.0 microg Epi, respectively. At 28 degrees C, Epi infusion was started in groups 4 and 5 with 0.125 and 1.25 microg/min, respectively. Group 6 served as saline control. After rewarming, both CO and stroke volume were restored in group 4, in contrast to groups 5 and 6, in which both CO and stroke volume remained significantly reduced (30%). Total peripheral resistance was significantly higher in group 5 during rewarming from 24 to 34 degrees C, compared with groups 4 and 6. This study shows that, in contrast to normothermic conditions, Epi infused during hypothermia induces vasoconstriction rather than vasodilation combined with lack of CO elevation. The apparent dissociation between myocardial and vascular responses to Epi at low temperatures may be related to hypothermia-induced myocardial failure and changes in temperature-dependent adrenoreceptor affinity.

The trochanteric gamma nail versus the dynamic hip screw: a prospective randomised study. One-year follow-up of 146 intertrochanteric fractures.

In a prospective, randomized trial we compared the trochanteric gamma nail (TGN) and the dynamic hip screw (DHS) in the treatment of 146 intertrochanteric fractures. Follow-up was after four and 12 months. The operation time was significantly shorter in the DHS group. At discharge the need for walking aids was less in the DHS group. There were no differences in intraoperative blood loss, medical complications, mortality or length of hospital stay. Major fracture complications occurred twiceas often in the TGN group compared with the DHS group, however they were not statistically significant. Any potential for the TGN leading to a less invasive procedure and a more rapid postoperative mobilisation could not be demonstrated. Compared with the TGN we prefer the DHS for most intertrochanteric fractures in a setting where the majority of these fractures are treated by younger doctors and not by highly specialized hip/trauma surgeons. The TGN may have advantages in selected intertrochanteric fractures.;