Advances in CaV1.1 gating: New insights into permeation and voltage-sensing mechanisms

The CaV1.1 voltage-gated Ca2+ channel carries L-type Ca2+ current and is the voltage-sensor for excitation-contraction (EC) coupling in skeletal muscle. Significant breakthroughs in the EC coupling field have often been close on the heels of technological advancement. In particular, CaV1.1 was the first voltage-gated Ca2+ channel to be cloned, the first ion channel to have its gating current measured and the first ion channel to have an effectively null animal model. Though these innovations have provided invaluable information regarding how CaV1.1 detects changes in membrane potential and transmits intra- and inter-molecular signals which cause opening of the channel pore and support Ca2+ release from the sarcoplasmic reticulum remain elusive. Here, we review current perspectives on this topic including the recent application of functional site-directed fluorometry.

Single- and Multilevel Corpectomy and Vertebral body replacement for treatment of spinal infections. A retrospective single-center study of 100 cases

Background

The optimal operative approach for treating spinal infections remains a subject of debate. Corpectomy and Vertebral Body Replacement (VBR) have emerged as common modalities, yet data on their feasibility and complication profiles are limited.

Methods

This retrospective single-center study examined 100 consecutive cases (2015-2022) that underwent VBR for spinal infection treatment. A comparison between Single-level-VBR and Multi-level-VBR was performed, evaluating patient profiles, revision rates, and outcomes.

Results

Among 360 cases treated for spinal infections, 100 underwent VBR, located in all spinal regions. Average clinical and radiologic follow-up spanned 1.5 years. Single-level-VBR was performed in 60 cases, Two-level-VBR in 37, Three-level-VBR in 2, and Four-level-VBR in one case.Mean overall sagittal correction reached 10° (range 0-54°), varying by region. Revision surgery was required in 31 cases. Aseptic mechanical complications (8% pedicle screw loosening, 3% cage subsidence, 6% aseptic adjacent disc disease) were prominent reasons for revision. Longer posterior constructs (>4 levels) had significantly higher revision rates (p < 0.01). General complications (wound healing, hematoma) followed, along with infection relapse and adjacent disc infection (9%) and neurologic impairment (1%).Multilevel-VBR (≥2 levels) displayed no elevated cage subsidence rate compared to Single-level-VBR. Three deaths occurred (43-86 days post-op), all in the Multi-level-VBR group.

Conclusion

This study, reporting the largest number of VBR cases for spinal infection treatment, affirmed VBR's effectiveness in sagittal imbalance correction. The overall survival was high, while reinfection rates matched other surgical studies. Anterior procedures have minimal implant related risks, but extended dorsal instrumentation elevates revision surgery likelihood.

Predictability of the virtual surgical plan for orthognathic surgery with the mandible surgery first sequence

The aim of this study was to compare the virtually planned position to the postoperative position of the maxilla, having performed the maxilla-first sequence or mandible-first sequence orthognathic surgery. An audit of 64 patients who underwent bimaxillary surgery between 2017 and 2020 was performed. Thirty patients had maxilla-first surgery and 34 had mandible-first surgery. The planned and post-surgical positions were analyzed using specific skeletal landmarks. Differences were calculated and the two-sample t-test was used to compare the groups. Measured differences between the planned and postoperative results differed significantly between the mandible-first and maxillary-first surgery groups (P < 0.001). The maxillary central incisors were under-advanced in the anterior-posterior direction in both groups. Most data points showed deviation from the surgical plan ≤ 2 mm and ≤ 4°. Secondarily, maxillary under-advancement in the mandible-first cohort was evaluated; these patients were subdivided into rigid and non-rigid fixation groups. The non-rigid fixation group showed less accuracy compared to the rigid fixation group, which was statistically significant (P = 0.014). The findings of this study demonstrate that virtual surgical planning can be less accurate in predicting the maxillary incisor position when performing mandible-first surgery, but this inaccuracy is within the acceptable range and can be mitigated by rigid fixation of the mandible.

An interactive feedback system for increasing hand antisepsis adherence in stationary intensive care

BACKGROUND

Pathogens causing infections are in many cases transmitted via the hands of personnel. Thus, hand antisepsis has strong epidemiological evidence of infection prevention. Depending on various factors, hand antisepsis adherence ranges between 9.1% and 85.2%.

AIM

To evaluate a new transponder system that reminded medical staff to use an alcohol-based hand rub based on indication by giving real-time feedback, to detect hand antisepsis adherence.

METHODS

The monitoring system consisted of three components: a portable transponder detecting alcohol-based hand rub and able to give feedback; a beacon recognizing entries to and exits from the patient's surroundings; and a sensor placed at the hand-rub dispensers to count the number of hand rubs. With these components, the system provided feedback when hand antisepsis was not conducted although it was necessary according to moments 1, 4, and 5 of hand antisepsis. Adherence was measured in two use-cases with five phases, starting with the baseline measurement followed by intervention periods and phases without intervention to test the sustainability of the feedback.

FINDINGS

Using the monitoring system, hand antisepsis adherence was increased by up to 104.5% in comparison to the baseline measurement. When the intervention ceased, however, hand antisepsis adherence decreased to less than or equal to the baseline measurement.

CONCLUSION

A short-term intervention alone is not sufficient to lead to a long-term change in hand antisepsis adherence. Rather, permanent feedback and/or the integration in a multi-modal intervention strategy are necessary.

The role of routine SARS-CoV-2 screening of healthcare-workers in acute care hospitals in 2020: a systematic review and meta-analysis

Background

Healthcare workers (HCW) are at increased risk of infection with SARS-CoV-2. Vulnerable patient populations in particular must be protected, and clinics should not become transmission hotspots to avoid delaying medical treatments independent of COVID. Because asymptomatic transmission has been described, routine screening of asymptomatic HCW would potentially be able to interrupt chains of infection through early detection.

Methods

A systematic search was conducted in the Cochrane COVID-19 Study Register, Web of Science and WHO COVID‐19 Global literature on coronavirus with regard to non-incident related testing of healthcare workers using polymerase chain reaction on May 4th 2021. Studies since January 2020 were included. An assessment of risk of bias and representativeness was performed.

Results

The search identified 39 studies with heterogeneous designs. Data collection of the included studies took place from January to August 2020. The studies were conducted worldwide and the sample size of the included HCW ranged from 70 to 9449 participants. In total, 1000 of 51,700 (1.9%) asymptomatic HCW were tested positive for SARS-CoV-2 using PCR testing. The proportion of positive test results ranged between 0 and 14.3%. No study reported on HCW-screening related reductions in infected person-days.

Discussion and conclusions

The heterogeneous proportions might be explained by different regional incidences, lock-downs, and pre-analytical pitfalls that reduce the sensitivity of the nasopharyngeal swab. The very high prevalence in some studies indicates that screening HCW for SARS-CoV-2 may be important particularly in geographical regions and pandemic periods with a high-incidence. With low numbers and an increasing rate of vaccinated HCW, a strict cost–benefit consideration must be made, especially in times of low incidences. Since we found no studies that reported on HCW-screening related reductions in infected person-days, re-evaluation should be done when these are available.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07554-5.

Surgical site infections: guidance for elective surgery during the SARS-CoV-2 pandemic - international recommendations and clinical experience

BACKGROUND

The COVID-19 pandemic not only had an impact on public life and healthcare facilities in general, but also affected established surgical workflows for elective procedures. The strategy to protect patients and healthcare workers from infection by SARS-CoV-2 in surgical departments has needed step-by-step development. Based on the evaluation of international recommendations and guidelines, as well as personal experiences in a clinical 'hot spot' and in a 450-bed surgical clinic, an adapted surgical site infection (SSI) prevention checklist was needed to develop concise instructions, which described roles and responsibilities of healthcare professionals that could be used for wider guidance in pandemic conditions.

METHOD

Publications of COVID-19-related recommendations and guidelines, produced by health authorities and organizations, such as WHO, US-CDC, ECDC, the American College of Surgery and the Robert Koch Institute, were retrieved, assessed and referenced up to 31st January 2020. Additionally, clinical personal experiences in Germany were evaluated and considered.

RESULTS

Part 1 of this guidance summarizes the experience of a tertiary care, surgical centre which utilized redundant hospital buildings for immediate spatial separation in a 'hot spot' COVID-19 area. Part 2 outlines the successful screening and isolation strategy in a surgical clinic in a region of Germany with outbreaks in surrounding medical centres. Part 3 provides the synopsis of personal experiences and international recommendations suggested for implementation during the COVID-19 pandemic.

CONCLUSION

Understanding of COVID-19, and SARS-CoV-2-related epidemiology, is constantly and rapidly changing, requiring continuous adaptation and re-evaluation of recommendations. Established national and local guidelines for continuation of surgical services and prevention of SSI require ongoing scrutiny and focused implementation. This manuscript presents a core facility checklist to support medical institutions to continue their clinical and surgical work during the COVID-19 pandemic.

Extensively-drug-resistant Klebsiella pneumoniae ST307 outbreak strain from north-eastern Germany does not show increased tolerance to quaternary ammonium compounds and chlorhexidine

BACKGROUND

An outbreak of extensively-drug-resistant Klebsiella pneumoniae strain ST307 in a cluster of hospitals in north-east Germany gave rise to the assumption that the epidemiological success of the strain could be based on increased tolerance to biocides.

METHODS

The tolerance of the outbreak strain was compared with epidemiologically unrelated clinical isolates of K. pneumoniae, and reference strains of Pseudomonas aeruginosa (ATCC 15442) and Escherichia coli K12 (NCTC 10538). Tests were performed in a miniaturized assay based on European Standard EN 1040. The widely used biocides benzalkonium chloride (BAC) and didecyl dimethyl ammonium chloride (DDAC), their commercial formulation Descosept spezial (DS), and the antiseptic agent chlorhexidine digluconate (CHG) were selected as test substances. These biocides are used regularly in the hospitals involved in the outbreak.

FINDINGS

All biocides had a bactericidal effect against all tested strains in the quantitative suspension test within 5 min at typically used concentrations and dilutions. The effectiveness of BAC and DDAC alone and in combination, and CHG antisepsis were not impaired under tested conditions.

CONCLUSION

The outbreak strain did not show significantly increased tolerance towards biocides regarding the antiseptic. Thus, the epidemiological success of the strain has to be ascribed to other causes, such as inadequate hand hygiene of visitors.

Venous Thromboembolism Prophylaxis in Neurocritical Care Patients: Are Current Practices, Best Practices?

BACKGROUND/OBJECTIVES

Venous thromboembolism (VTE) is a leading cause of preventable, in-hospital deaths; critically ill patients have a higher risk. Effective and efficient strategies to prevent VTE exist; however, neurocritical care patients present unique challenges due to competing risk of bleeding. The objective of this study was to examine current VTE prophylaxis practices among neurocritical care patients, concordance with guideline-recommended care, and the association with clinical outcomes.

METHODS

This retrospective cohort study of patients admitted to ten adult, medical-surgical and neurological intensive care units (ICUs) in nine hospitals between 2014 and 2017 using administrative and clinical data. Neurocritical care patients were classified based on the primary admission diagnosis. Concordance with guideline-recommended care was evaluated using recommendations from recent guidelines.

RESULTS

20.0% of 23,191 patients were classified as neurocritical care. Among neurocritical care patients, pharmacological VTE prophylaxis was administered on 60.9% of all ICU days, mechanical VTE prophylaxis on 46.9%, and no VTE prophylaxis on 12.2% of all ICU days. Type of VTE prophylaxis was associated with sex, neurological diagnosis, and invasive neurological monitoring. Fifty-six percentage of ICU days were guideline concordant but concordance varied by recommendation (range 6-100%) and by type of VTE prophylaxis recommended (p = 0.05); among patients where guidelines recommended use of pharmacologic prophylaxis, care was concordant 26.6% of ICU days, whereas for mechanical prophylaxis it was concordant 80.5% of ICU days. There was an overall improvement in guideline concordance on 2.3% of ICU days after the publication of the Society of Neurocritical Care guideline (p = 0.005).

CONCLUSIONS

Neurocritical care patients commonly receive mechanical VTE prophylaxis despite guidelines recommending the use of pharmacological VTE prophylaxis. Our findings suggest uncertainty around best VTE prophylaxis practices for neurocritical care patients remains.

Do pneumatic tube transport systems transmit potential pathogens? A hygienic risk assessment in a university hospital

BACKGROUND

Prompted by an outbreak of vancomycin-resistant enterococci (VRE) in a medical facility, this study examined a pneumatic tube transport system (PTS) as a potential transmission channel.

METHOD

Samples from the receiving station and entry racks were gathered via smear technique. Sponges used for PTS decontamination were soaked with 0.89% NaCl and transported through the channel. Micro-organisms were recovered from the tubes and cleaning sponges using a wash-away technique. Air sampling was performed at the receiving station in order to detect any airborne contamination. Tubes were artificially inoculated with Escherichia coli K12 NCTC 10538 and Staphylococcus epidermidis DSM 20044 and sent through the PTS to investigate channel contamination.

RESULTS

No pathogens were detected in effluent air from the PTS or in tubes during routine operation. Entry racks for the test tubes were contaminated with coagulase-negative staphylococci (CNS), aerobic bacilli, moulds and vancomycin-susceptible Enterococcus faecium. E. coli proved to be unsuitable for detecting bacterial transmission by the PTS due to low persistence, but S. epidermidis was more resilient. After sending contaminated test tubes through the PTS, levels of S. epidermidis only decreased marginally. Subsequently, sponges soaked with disinfectant solution were put through the system and these eliminated S. epidermidis completely from the first attempt.

DISCUSSION

Routine hygienic maintenance of the PTS makes pathogen transmission highly unlikely, although entry racks should be disinfected regularly. Any involvement of the PTS in the VRE outbreak at the study institution was unlikely.

Hand antisepsis without decreasing efficacy by shortening the rub-in time of alcohol-based handrubs to 15 seconds

BACKGROUND

A previous study among neonatal intensive care unit (NICU) nurses showed that the antibacterial efficacy of alcohol-based handrubs (ABHR) can be achieved in 15 s instead of 30 s with a significant increase in the frequency of hand antisepsis. This study aimed to examine 15-s vs 30-s antisepsis performance by measuring microbial load on fingertips and compliance among nurses in a low-risk gynaecological ward.

METHODS

An independent trained observer monitored the frequency and compliance with hand antisepsis during shifts in a crossover design. Fingertips including thumbs were rinsed in soy broth before hand rubbing at the beginning of a shift and then hourly to determine the bacterial load. Performance activity was assigned to the contamination class of the Fulkerson scale. Immediately before the lunch break, volunteers cleaned their hands for a randomly determined application time of 15 or 30 s.

RESULTS

Examination of bacterial load on fingertips revealed no difference between 15 vs 30 s application time. Controlled hand antisepsis before the lunch break also showed no difference in efficacy for either test series. Participants rubbing for 15 s were more likely to perform hand antisepsis compared with those rubbing for 30 s (P=0.2). The compliance increased from 54.7% to 69.5% in the 15-s trial.

DISCUSSION

Shortening the duration for hand antisepsis did not decrease efficacy. Shortening the application time to 15 s should be considered within the critical components of a successful multimodal intervention strategy to improve hand-hygiene compliance in clinical practice.

Cold atmospheric pressure plasma for treatment of chronic wounds: drug or medical device?

OBJECTIVE

The use of cold atmospheric pressure plasma (CAPP) as a new therapeutic option to aid the healing of chronic wounds appears promising. Currently, uncertainty exists regarding their classification as medical device or medical drug. Because the classification of CAPP has medical, legal, and economic consequences as well as implications for the level of preclinical and clinical testing, the correct classification is not an academic exercise, but an ethical need.

METHOD

A multidisciplinary team of physicians, surgeons, pharmacists, physicists and lawyers has analysed the physical and technical characteristics as well as legal conditions of the biological action of CAPP.

RESULTS

It was concluded that the mode of action of the locally generated CAPP, with its main active components being different radicals, is pharmacological and not physical in nature.

CONCLUSION

Depending on the intended use, CAPP should be classified as a drug, which is generated by use of a medical device directly at the point of therapeutic application.

SEIS: Insight's Seismic Experiment for Internal Structure of Mars

By the end of 2018, 42 years after the landing of the two Viking seismometers on Mars, InSight will deploy onto Mars' surface the SEIS (Seismic Experiment for Internal Structure) instrument; a six-axes seismometer equipped with both a long-period three-axes Very Broad Band (VBB) instrument and a three-axes short-period (SP) instrument. These six sensors will cover a broad range of the seismic bandwidth, from 0.01 Hz to 50 Hz, with possible extension to longer periods. Data will be transmitted in the form of three continuous VBB components at 2 sample per second (sps), an estimation of the short period energy content from the SP at 1 sps and a continuous compound VBB/SP vertical axis at 10 sps. The continuous streams will be augmented by requested event data with sample rates from 20 to 100 sps. SEIS will improve upon the existing resolution of Viking's Mars seismic monitoring by a factor of ∼ 2500 at 1 Hz and ∼ 200 000 at 0.1 Hz. An additional major improvement is that, contrary to Viking, the seismometers will be deployed via a robotic arm directly onto Mars' surface and will be protected against temperature and wind by highly efficient thermal and wind shielding. Based on existing knowledge of Mars, it is reasonable to infer a moment magnitude detection threshold of M w ∼ 3 at 40 ∘ epicentral distance and a potential to detect several tens of quakes and about five impacts per year. In this paper, we first describe the science goals of the experiment and the rationale used to define its requirements. We then provide a detailed description of the hardware, from the sensors to the deployment system and associated performance, including transfer functions of the seismic sensors and temperature sensors. We conclude by describing the experiment ground segment, including data processing services, outreach and education networks and provide a description of the format to be used for future data distribution.

ELECTRONIC SUPPLEMENTARY MATERIAL

The online version of this article (10.1007/s11214-018-0574-6) contains supplementary material, which is available to authorized users.

Four steps to clean hospitals: LOOK, PLAN, CLEAN and DRY

BACKGROUND

Now that cleaning and decontamination are recognized as integral to infection control, it is timely to examine the process in more detail. This is because cleaning practices vary widely within healthcare districts, and it is likely that both time and energy are needlessly wasted with ill-defined duties. Furthermore, inadequate cleaning will not reduce the risk of infection but may even enhance it. The process would benefit from a systematic appraisal, with each component placed within an evidence-based and ordered protocol.

METHODS

A literary search was performed on 'hospital cleaning', focusing on manual aspects of cleaning, pathogen reservoirs and transmission, hand hygiene, staff responsibilities and patient comfort.

RESULTS

No articles providing an evidence-based practical approach to systematic cleaning in hospitals were identified. This review therefore proposes a simple four-step guide for daily cleaning of the occupied bed space. Step 1 (LOOK) describes a visual assessment of the area to be cleaned; Step 2 (PLAN) argues why the bed space needs preparation before cleaning; Step 3 (CLEAN) covers surface cleaning/decontamination; and Step 4 (DRY) is the final stage whereby surfaces are allowed to dry.

CONCLUSION

Given the lack of articles providing practical cleaning guidance, this review proposes a four-step protocol based on evidence if available, or justified where not. Each step is presented, discussed and risk-assessed. It is likely that a systematic cleaning process would reduce the risk of healthcare-associated infection for everyone, including outbreaks, in addition to heightened confidence in overall quality of care.

[Spectrum of pathogens in postoperative complications of visceral surgery : The problem of multidrug resistance]

In general surgery the etiology of surgical site infections has not significantly changed over the last 30 years. Gram-positive bacteria, e.g. coagulase negative staphylococci (CNS), Staphylococcus aureus and Enterococcus spp. as well as Gram-negative bacteria, e.g. Escherichia coli, Enterobacter spp., Klebsiella spp. and Pseudomonas aeruginosa, are the most common findings. Although in general surgery 10% of the S. aureus causing postoperative wound infections were methicillin resistant (MRSA), no cases of multidrug-resistant Gram-negative (MRGN) bacteria were reported. Yeasts (particularly Candida spp.) are rarely the pathogen causing surgical site infections (≤3%) and concomitant risk factors are typical (e.g. diabetes, chemotherapy, immunosuppression and malnutrition). Viruses are rarely the cause of surgical site infections. Transmission can occur by HBV, HCV or HIV positive surgical staff or in organ transplantations and postoperative reactivation of persistent infections is possible (especially for HBV, HCV, CMV, EBV and HIV). The principles for prevention of surgical site infections are dealt with as consequences of preoperative colonization by MRSA, methicillin-sensitive S. aureus (MSSA) and MRGN and reviewed with respect to screening, perioperative antibiotic prophylaxis and decolonization. In nosocomial peritonitis, the selection of antibiotics should consider previous antibiotic treatment. A single intra-abdominal detection of Candida spp. usually does not require antimycotic treatment in postoperatively stable and immunocompetent patients but is recommended in severe community-acquired or nosocomial peritonitis. Viral infections can be avoided by screening of organ donors and serological surveillance of surgery personnel.

[Enterococci and surgical site infections : Causal agent or harmless commensals?]

BACKGROUND

The role of enterococci in the context of peritonitis and surgical site infections (SSI) has not yet been definitively clarified but enterococci are being detected more frequently. Numerous resistances reduce the available antibiotic options.

OBJECTIVE

This article gives an overview of the pathogenic importance of enterococci and of current recommendations for therapy and prophylaxis. On the basis of our own data we discuss the relevance of enterococci for SSI.

MATERIAL AND METHODS

All colorectal resections carried out between January 2008 and September 2016 were retrospectively documented. Revision surgery, SSI and intra-abdominally or subcutaneously detected pathogens were recorded.

RESULTS

A total of 2713 interventions were evaluated with 28.3% having primary peritonitis. In 587 patients (21.6%) SSI followed, and pathogen determination was possible in 431 cases (73.4%). Enterococci were frequently found in re-operations (58.4%) and SSI (46.1%), with E. faecalis and E. faecium in approximately equal proportions. If intra-abdominal enterococci were detectable in patients with primary peritonitis, it was more common to develop SSI and enterococci were more frequently detected subcutaneously. Enterococci in SSI were found to be significantly more frequent in left hemicolectomies as well as in pre-existing renal insufficiency.

CONCLUSION

It can be inferred that enterococci are not adequately covered by commonly used perioperative antibiotic therapy or preoperative prophylaxis, which increases the risk for SSI by enterococci. This could be favored by selection of these pathogens due to the use of antibiotics without enterococcal efficacy (e. g. cephalosporins). The consideration in the choice of perioperative antibiotic prophylaxis by the additional administration of ampicillin or vancomycin could be advantageous.

Comparison of chlorhexidine–isopropanol with isopropanol skin antisepsis for prevention of surgical-site infection after abdominal surgery

Background

Prevention of surgical-site infection (SSI) has received increasing attention. Clinical trials have focused on the role of skin antisepsis in preventing SSI. The benefit of combining antiseptic chlorhexidine with alcohol has not been compared with alcohol-based skin preparation alone in a prospective controlled clinical trial.

Methods

Between August and October 2014, patients undergoing abdominal surgery received preoperative skin antisepsis with 70 per cent isopropanol (PA). Those treated between November 2014 and January 2015 received 2 per cent chlorhexidine with 70 per cent isopropanol (CA). The primary endpoint was SSI on postoperative day (POD) 10, which was evaluated using univariable analysis, and a multivariable logistic regression model correcting for known independent risk factors for SSI. The study protocol was published in the German Registry of Clinical Studies (DRKS00011174).

Results

In total, 500 patients undergoing elective midline laparotomy were included (CA 221, PA 279). The incidence of superficial and deep SSIs was significantly different on POD 10: 14 of 212 (6·6 per cent) among those treated with CA and 32 of 260 (12·3 per cent) in those who received PA (P = 0·038). In the multivariable analysis, skin antisepsis with CA was an independent factor for reduced incidence of SSI on POD 10 (P = 0·034).

Conclusion

This study showed a benefit of adding chlorhexidine to alcohol for skin antisepsis in reducing early SSI compared with alcohol alone.

Effect of antiseptic irrigation on infection rates of traumatic soft tissue wounds: a longitudinal cohort study

OBJECTIVE

Acute traumatic wounds are contaminated with bacteria and therefore an infection risk. Antiseptic wound irrigation before surgical intervention is routinely performed for contaminated wounds. However, a broad variety of different irrigation solutions are in use. The aim of this retrospective, non-randomised, controlled longitudinal cohort study was to assess the preventive effect of four different irrigation solutions before surgical treatment, on wound infection in traumatic soft tissue wounds.

METHOD

Over a period of three decades, the prophylactic application of wound irrigation was studied in patients with contaminated traumatic wounds requiring surgical treatment, with or without primary wound closure. The main outcome measure was development of wound infection. From 1974-1983, either 0.04 % polihexanide (PHMB), 1 % povidone-iodine (PVP-I), 4 % hydrogen peroxide, or undiluted Ringer's solution were concurrently in use. From 1984-1996, only 0.04 % PHMB or 1 % PVP-I were applied. From 1997, 0.04 % PHMB was used until the end of the study period in 2005.

RESULTS

The combined rate for superficial and deep wound infection was 1.7 % in the 0.04 % PHMB group (n=3264), 4.8 % in the 1 % PVP-I group (n=2552), 5.9 % in the Ringer's group (n=645), and 11.7 % in the 4 % hydrogen peroxide group (n=643). Compared with all other treatment arms, PHMB showed the highest efficacy in preventing infection in traumatic soft tissue wounds (p<0.001). However, compared with PVP-I, the difference was only significant for superficial infections.

CONCLUSION

The large patient numbers in this study demonstrated a robust superiority of 0.04 % PHMB to prevent infection in traumatic soft tissue wounds. These retrospective results may further provide important information as the basis for power calculations for the urgently needed prospective clinical trials in the evolving field of wound antisepsis.

[Acute therapeutic measures for limb salvage Part 2 : Debridement, lavage techniques and anti-infectious strategies]

The quality of the primary care of Gustilo-Anderson (GA) type IIIB and IIIC extremity injuries is crucial to the success of the limb salvage procedure. This article provides a compilation of consistent, but often controversially discussed aspects of initial debridement, modern techniques of lavage and wound closure, in addition to current issues on the application of antibiotics and antiseptics, based on our own experiences and the latest literature. The following points should be stressed. Severe extremity injuries with gross contamination (GA IIIA, B, and C) will still be associated with an infection rate of up to 60 %. The initial debridement should be performed as soon as an experienced trauma surgeon is available. Tissue that is definitely avital will have to be removed, whereas traumatized but potentially surviving tissue will have to be re-evaluated during a second-look operation after 36-48 h. Given a high enough level of contamination, biofilms will form after as few as 6 h. The perioperative antibiotic prophylaxis has to be initiated early and should be continued for at least 24 h (GA I/II) or up to 5 days (GA III). In cases of bacterial contamination, wound irrigation will be useful with additives such as polyhexanide, octenidine or superoxidized water. Rinsing of the wound should be performed with 3-9 L and only slight manual pressure (no jet lavage). The definitive primary closure of a wound should be achieved in the initial operation, but only in the case of certain "decontamination" and overall vitality of the wound (GA I and II). In the presence of high-grade injuries, a temporary vacuum sealing technique can be used until the earliest possible definitive plastic surgical wound closure.

Conditioning hops increase triceps surae muscle force and Achilles tendon strain energy in the stretch-shortening cycle

Postactivation potentiation can improve athletic performance, but the underlying mechanisms are poorly understood. This study investigated the effect of conditioning hops on triceps surae muscle force and tendon strain and its contribution to potentiated stretch-shortening cycle (SSC) performance. Thirty-two subjects participated in two experiments. In both experiments, subjects performed three drop jumps (DJs) after prior conditioning with 10 maximal hops, three unconditioned DJs served as control. Ground reaction forces, kinematics, and triceps surae electromyographic activity were recorded. Ultrasound imaging was used to determine fascicle lengths (FASC) of the gastrocnemius (GM) and soleus muscles (experiment 1) and the length of the Achilles tendon (experiment 2) during the DJs. DJ height after the conditioning hops was significantly higher compared to control DJs (experiment 1: +12% and experiment 2: +19%). A significantly shorter GM FASC during the DJs performed after the conditioning hops coincided with an increased force acting on the triceps surae muscle. Moreover, the triceps surae muscle-tendon unit (MTU) showed increased energy absorption during the eccentric phase of the DJs and increased energy release during the concentric phase. The second experiment revealed a higher Achilles tendon strain in DJs performed after the conditioning hops compared to control DJs. No significant differences in muscle activities were observed. The shorter FASC in GM and the larger Achilles tendon strain facilitated MTU energy transfer from the eccentric to the concentric phase during the DJ. Thereby, conditioning hops improved SSC efficacy and DJ performance.

Postactivation potentiation can counteract declines in force and power that occur after stretching

Stretching can decrease a muscle's maximal force, whereas short but intense muscle contractions can increase it. We hypothesized that when combined, postactivation potentiation induced by reactive jumps would counteract stretch-induced decrements in drop jump (DJ) performance. Moreover, we measured changes in muscle twitch forces and ankle joint stiffness (K_Ankle ) to examine underlying mechanisms. Twenty subjects completed three DJs and 10 electrically evoked muscle twitches of the triceps surae subsequent to four different conditioning activities and control. The conditioning activities were 10 hops, 20s of static stretching of the triceps surae muscle, 20s of stretching followed by 10 hops, and vice versa. After 10 hops, twitch peak torque (TPT) was 20% and jump height 5% higher compared with control with no differences in K_Ankle . After stretching, TPT and jump height were both 9% and K_Ankle 6% lower. When hops and stretching were combined as conditioning activities, jump height was not different compared with control but significantly higher (11% and 8%) compared with stretching. TPTs were 16% higher compared with control when the hops were performed after stretching and 9% higher compared with the reverse order. K_Ankle was significantly lower when stretching was performed after the hops (6%) compared with control, but no significant difference was observed when hops were performed after stretching. These results demonstrate that conditioning hops can counteract stretch-related declines in DJ performance. Furthermore, the differences in TPTs and K_Ankle between combined conditioning protocols indicate that the order of conditioning tasks might play an important role at the muscle-tendon level.

Aneurysmal SubArachnoid Hemorrhage-Red Blood Cell Transfusion And Outcome (SAHaRA): a pilot randomised controlled trial protocol

INTRODUCTION

Anaemia is common in aneurysmal subarachnoid haemorrhage (aSAH) and is a potential critical modifiable factor affecting secondary injury. Despite physiological evidence and management guidelines that support maintaining a higher haemoglobin level in patients with aSAH, current practice is one of a more restrictive approach to transfusion. The goal of this multicentre pilot trial is to determine the feasibility of successfully conducting a red blood cell (RBC) transfusion trial in adult patients with acute aSAH and anaemia (Hb ≤100 g/L), comparing a liberal transfusion strategy (Hb ≤100 g/L) with a restrictive strategy (Hb ≤80 g/L) on the combined rate of death and severe disability at 12 months.

METHODS

Design This is a multicentre open-label randomised controlled pilot trial at 5 academic tertiary care centres. Population We are targeting adult aSAH patients within 14 days of their initial bleed and with anaemia (Hb ≤110 g/L). Randomisation Central computer-generated randomisation, stratified by centre, will be undertaken from the host centre. Randomisation into 1 of the 2 treatment arms will occur when the haemoglobin levels of eligible patients fall to ≤100 g/L. Intervention Patients will be randomly assigned to either a liberal (threshold: Hb ≤100 g/L) or a restrictive transfusion strategy (threshold: Hb ≤80 g/L). Outcome Primary: Centre randomisation rate over the study period. Secondary: (1) transfusion threshold adherence; (2) study RBC transfusion protocol adherence; and (3) outcome assessment including vital status at hospital discharge, modified Rankin Score at 6 and 12 months and Functional Independence Measure and EuroQOL Quality of Life Scale scores at 12 months. Outcome measures will be reported in aggregate.

ETHICS AND DISSEMINATION

The study protocol has been approved by the host centre (OHSN-REB 20150433-01H). This study will determine the feasibility of conducting the large pragmatic RCT comparing 2 RBC transfusion strategies examining the effect of a liberal strategy on 12-month outcome following aSAH.

TRIAL REGISTRATION NUMBER

NCT02483351; Pre-results.

Measurements of chlorhexidine, p-chloroaniline, and p-chloronitrobenzene in saliva after mouth wash before and after operation with 0.2% chlorhexidine digluconate in maxillofacial surgery: a randomised controlled trial

Chlorhexidine gluconate is used to prevent the accumulation of dental plaque and gingivitis, infection of the surgical site, and ventilator-associated pneumonia in maxillofacial surgery, but it is not clear whether the metabolites of chlorhexidine are detectable in the patient's saliva at clinically relevant concentrations. Forty-three patients who had orofacial operations were randomised to use a 0.2% chlorhexidine gluconate (n=23), or an octenidine-based, chlorhexidine-free (n=20), mouthwash once preoperatively and three times daily for five postoperative days. After the first, 8.7 (23.3) mg/L chlorhexidine (0.7%-2.5% of the total amount used) was measured in saliva. The concentration increased to 15.2 (6.2) mg/L after the second rinse (first postoperative day), and peaked at 29.4 (11.2) mg/L on the fourth postoperative day. It remained detectable for up to 12hours after the last one, but was not detectable in serum or urine at any time. The potentially carcinogenic metabolite p-chloroaniline was detectable in saliva at higher concentrations in the chlorhexidine group (0.55mg/L) than the octenidine group (0.21mg/L), and p-chloronitrobenzene was detected in both groups in only minimal concentrations (0.001-0.21mg/L). Chlorhexidine gluconate mouthwashes do increase the concentration of p-chloroaniline, but a single use seems to be safe. Whether prolonged exposure over many years may have carcinogenic potential is still not clear. Based on the hitherto unknown kinetics of p-chloroaniline in saliva, the recent recommendation of the Federal Drug Administration (FDA) in the USA to limit the use of a chlorhexidine gluconate mouthwash to a maximum of six months seems to be justified.

Regulation of the clock gene expression in human adipose tissue by weight loss

BACKGROUND

The circadian clock coordinates numerous metabolic processes to adapt physiological responses to light-dark and feeding regimens and is itself regulated by metabolic cues. The implication of the circadian clock in the regulation of energy balance and body weight is widely studied in rodents but not in humans. Here we investigated (1) whether the expression of clock genes in human adipose tissue is changed by weight loss and (2) whether these alterations are associated with metabolic parameters.

SUBJECTS/METHODS

Subcutaneous adipose tissue (SAT) samples were collected before and after 8 weeks of weight loss on an 800 kcal per day hypocaloric diet (plus 200 g per day vegetables) at the same time of the day. Fifty overweight subjects who lost at least 8% weight after 8 weeks were selected for the study. The expression of 10 clock genes and key metabolic and inflammatory genes in adipose tissue was determined by quantitative real-time PCR.

RESULTS

The expression of core clock genes PER2 and NR1D1 was increased after the weight loss. Correlations of PERIOD expression with body mass index (BMI) and serum total, high-density lipoprotein and low-density lipoprotein (LDL) cholesterol levels and of NR1D1 expression with total and LDL cholesterol were found that became non-significant after correction for multiple testing. Clock gene expression levels and their weight loss-induced changes tightly correlated with each other and with genes involved in fat metabolism (FASN, CPT1A, LPL, PPARG, PGC1A, ADIPOQ), energy metabolism (SIRT1), autophagy (LC3A, LC3B) and inflammatory response (NFKB1, NFKBIA, NLRP3, EMR1).

CONCLUSION

Clock gene expression in human SAT is regulated by body weight changes and associated with BMI, serum cholesterol levels and the expression of metabolic and inflammatory genes. Our data confirm the tight crosstalk between molecular clock and metabolic and inflammatory pathways involved in adapting adipose tissue metabolism to changes of the energy intake in humans.

Attitudes and perceptions of health care workers in Northeastern Germany about multidrug-resistant organisms

There were 256 health care workers in 39 facilities who were interviewed about their perceptions of the quality of care of patients with and without multidrug-resistant organisms based on a standardized questionnaire. There are remarkable differences in the responses between facility types (acute care hospitals, long-term care hospitals, rehabilitation hospitals, and home care services). Hygiene management must be specifically tailored to the requirements of each facility.