Resolving colistin resistance and heteroresistance in Enterobacter species

Species within the Enterobacter cloacae complex (ECC) include globally important nosocomial pathogens. A three-year study of ECC in Germany identified Enterobacter xiangfangensis as the most common species (65.5%) detected, a result replicated by examining a global pool of 3246 isolates. Antibiotic resistance profiling revealed widespread resistance and heteroresistance to the antibiotic colistin and detected the mobile colistin resistance (mcr)-9 gene in 19.2% of all isolates. We show that resistance and heteroresistance properties depend on the chromosomal arnBCADTEF gene cassette whose products catalyze transfer of L-Ara4N to lipid A. Using comparative genomics, mutational analysis, and quantitative lipid A profiling we demonstrate that intrinsic lipid A modification levels are genospecies-dependent and governed by allelic variations in phoPQ and mgrB, that encode a two-component sensor-activator system and specific inhibitor peptide. By generating phoPQ chimeras and combining them with mgrB alleles, we show that interactions at the pH-sensing interface of the sensory histidine kinase phoQ dictate arnBCADTEF expression levels. To minimize therapeutic failures, we developed an assay that accurately detects colistin resistance levels for any ECC isolate.

[Elderly patients with an abdominal aortic aneurysm; preoperative frailty-screening and a multidisciplinary approach]

Aneurysm of the abdominal aorta is common and can be treated with endovascular repair, open surgical repair or conservative treatment. Risk-stratification and treatment decision-making can be complex in frail patients and depends largely on anatomy, life-expectancy and functional capacity. Currently, risk-stratification in the Netherlands is primarily based on comorbidities and age. Insight in a patient's resilience could provide important additional information. For this reason, St. Antonius hospital has implemented an Anaesthesia Geriatric Evaluation (AGE) to screen for frailty in high risk vascular surgery patients. Results of frailty-screening are discussed in a multi-disciplinary team (MDT) to assess perioperative risk and compose a personal treatment plan. This paper presents a case-series of three patients to illustrate the additional value of MDT care and frailty-screening in a high-risk vascular surgery population.

Editor's Choice - Nationwide Analysis of Patients Undergoing Iliac Artery Aneurysm Repair in the Netherlands

OBJECTIVE

The new 2019 guideline of the European Society for Vascular Surgery (ESVS) recommends consideration for elective iliac artery aneurysm (eIAA) repair when the iliac diameter exceeds 3.5 cm, as opposed to 3.0 cm previously. The current study assessed diameters at time of eIAA repair and ruptured IAA (rIAA) repair and compared clinical outcomes after open surgical repair (OSR) and endovascular aneurysm repair (EVAR).

METHODS

This retrospective observational study used the nationwide Dutch Surgical Aneurysm Audit (DSAA) registry that includes all patients who undergo aorto-iliac aneurysm repair in the Netherlands. All patients who underwent primary IAA repair between 1 January 2014 and 1 January 2018 were included. Diameters at time of eIAA and rIAA repair were compared in a descriptive fashion. The anatomical location of the IAA was not registered in the registry. Patient characteristics and outcomes of OSR and EVAR were compared with appropriate statistical tests.

RESULTS

The DSAA registry comprised 974 patients who underwent IAA repair. A total of 851 patients were included after exclusion of patients undergoing revision surgery and patients with missing essential variables. eIAA repair was carried out in 713 patients, rIAA repair in 102, and symptomatic IAA repair in 36. OSR was performed in 205, EVAR in 618, and hybrid repairs and conversions in 28. The median maximum IAA diameter at the time of eIAA and rIAA repair was 43 (IQR 38-50) mm and 68 (IQR 58-85) mm, respectively. Mortality was 1.3% (95% CI 0.7-2.4) after eIAA repair and 25.5% (95% CI 18.0-34.7) after rIAA repair. Mortality was not significantly different between the OSR and EVAR subgroups. Elective OSR was associated with significantly more complications than EVAR (intra-operative: 9.8% vs. 3.6%, post-operative: 34.0% vs. 13.8%, respectively).

CONCLUSION

In the Netherlands, most eIAA repairs are performed at diameters larger than recommended by the ESVS guideline. These findings appear to support the recent increase in the threshold diameter for eIAA repair.

Laser-induced vapor nanobubbles improve diffusion in biofilms of antimicrobial agents for wound care

Being responsible for delayed wound healing, the presence of biofilms in infected wounds leads to chronic, and difficult to treat infections. One of the reasons why antimicrobial treatment often fails to cure biofilm infections is the reduced penetration rate of antibiotics through dense biofilms. Strategies that have the ability to somehow interfere with the integrity of biofilms and allowing a better penetration of drugs are highly sought after. A promising new approach is the use of laser-induced vapor nanobubbles (VNB), of which it was recently demonstrated that it can substantially enhance the penetration of antibiotics into biofilms, resulting in a marked improvement of the killing efficiency. In this study, we examined if treatment of biofilms with laser-induced vapor nanobubbles (VNB) can enhance the potency of antimicrobials which are commonly used to treat wound infections, including povidone-iodine, chlorhexidine, benzalkonium chloride, cetrimonium bromide and mupirocin. Our investigations were performed on Pseudomonas aeruginosa and Staphylococcus aureus biofilms, which are often implicated in chronic wound infections. Pre-treatment of biofilms with laser-induced VNB did enhance the killing efficiency of those antimicrobials which experience a diffusion barrier in the biofilms, while this was not the case for those compounds for which there is no diffusion barrier. The magnitude of the enhanced potency was in most cases similar to the enhancement that was obtained when the biofilms were completely disrupted by vortexing and sonication. These results show that laser-induced VNB are indeed a very efficient way to enhance drug penetration deep into biofilms, and pave the way towards clinical translation of this novel approach for treatment of wound infections.

Correction to: Percutaneous Deep Venous Arterialization for Severe Critical Limb Ischemia in Patients With No Option of Revascularization: Early Experience From Two European Centers

The fifth author's name was incorrectly published as "M. Messas". The correct name is "E. Messas". The original article has been corrected.

Applicability of generic quality indicators for appropriate antibiotic use in daily hospital practice: a cross-sectional point-prevalence multicenter study

The ability to monitor the appropriateness of hospital antibiotic use is a key element of an effective antibiotic stewardship program. A set of 11 generic quality indicators (QIs) was previously developed to assess the quality of antibiotic use in hospitalized adults treated for a bacterial infection. The primary aim of the current study was to assess the clinimetric properties of these QIs (nine process and two structure indicators) in daily clinical practice. In a cross-sectional point-prevalence survey, performed in 2011 and 2012, 1890 inpatients from 22 hospitals in the Netherlands treated with antibiotics for a suspected bacterial infection were included, and data were extracted from medical records. In this cohort we tested the measurability, applicability, reliability, room for improvement and case mix stability of the previously developed QIs. Low applicability (≤10% of reviewed patients) was found for the QIs 'therapeutic drug monitoring', 'adapting antibiotics to renal function' and 'discontinue empirical therapy in case of lack of clinical and/or microbiological evidence of infection'. For the latter, we also found a low inter-observer agreement (kappa <0.4). One QI showed low improvement potential. The remaining seven QIs had sound clinimetric properties. Case-mix correction was necessary for most process QIs. For all QIs, we found ample room for improvement and large variation between hospitals. Establishing the clinimetric properties was essential, as four of the 11 previously selected QIs showed unsatisfactory properties in this practice test. Since the quality of antibiotic use and the process of documenting data is changing over time and may vary per country, QIs should always be tested in practice first.

An undetected common renal arterial trunk: surgical consequences and morbidity analysis

We present a patient with a recurrent precaval left renal artery, stemming from a right-sided common trunk renal artery. The patient was a 44-year male who presented with a post-traumatic grade IV renal injury. After 3 months without renal function improvement and repeated urinary tract infection, a laparoscopic nephrectomy of the affected right kidney was performed, without upfront identification of the vascular variation, resulting in ischemia of the remaining left kidney. An anastomosis of the common renal trunk and the distal left renal artery was created in between the abdominal aorta and the inferior vena cava. This case describes the importance of upfront detection of renal vascular variations using the appropriate imaging techniques.

Results of reinterventions for failed endovascular aortic repair: a single-center experience

AIM

The aim of this paper was to review technical success and clinical outcome of reinterventions to treat complications after endovascular abdominal aortic aneurysm (AAA) repair (EVAR) in a tertiary vascular center.

METHODS

The study enrolled 107 patients treated for post-EVAR complications between January 2005 and March 2014. Details of reinterventions, technical success, and midterm clinical outcome were analyzed for reinterventions. Radiologic follow-up after reinterventions was performed by computed tomography scans and duplex ultrasonography.

RESULTS

Indications for reinterventions in the 107 patients were predominantly endoleaks type Ia, Ib, II, and III (55.1%). Endograft obstructions were observed in 39 patients (36.4%). The initial technical success rate for the 107 reinterventions was 93.5% (N.=100). Median follow-up postreintervention was 20 months (range, 1-107 months). During follow-up, 34 of 107 patients (31.8%) needed at least one renewed reintervention. Kaplan-Meier analysis of overall survival after the primary reinterventions was 85% at 1 year, and 78% at 3 years of follow-up. AAA/EVAR-associated mortality was 4% at 3 years. Kaplan-Meier survival estimation of freedom of recurrence was 88% at 1 year post-reintervention and 78% at 3 years. Renewed reintervention-free survival dropped to 78% at 1 year and 58% at 3 years.

CONCLUSION

In this series of patients, the technical success rate of reinterventions to treat post-EVAR complications was high. During a median follow-up of 20 months, AAA-associated mortality is low, but the need for renewed (endovascular) reinterventions is substantial.

CT angiography to evaluate hemodynamic changes in popliteal artery aneurysms during flexion and extension of the knee joint

AIM

The aim of this study was to find out which characteristics of an asymptomatic popliteal artery aneurysm (PAA) will increase the risk for acute thrombosis.

METHODS

This was a single-center prospective study of consecutive patients with asymptomatic PAAs presenting from January 2010 to April 2012. Computed tomography angiography was used to perform measurements of the PAA during 0º extension and 90º flexion of the knee. After semi-automated segmentation of the popliteal artery (PA) lumen, a center lumen line (CLL) was automatically constructed.

RESULTS

The study included 16 asymptomatic PAAs. Median lumen area of the PA was directly proximal and distal of the PAA 57 mm2 (IQR, 44-87 mm2) and 46 mm2 (IQR, 32-66 mm2) in extension vs. 51 mm2 (IQR, 38-73 mm2) and 38 mm2 (IQR, 30-62 mm2) during 90º flexion, respectively (P=0.007) and (P=0.03). The median of the greatest decrease in lumen area after flexion and extension of the knee was 36 mm (IQR, 28-48 mm) in PAAs≥30 mm compared with 11 mm (IQR, 4-18 mm) in PAAs<30 mm (P<0.05). The proximal angulation was a median 48° in extension (IQR, 27-61º) and 75° during flexion (IQR, 46-99º; P=0.02). Distal angulation was a median of 31° (IQR, 21-42º) after extension vs. 62° (IQR, 33-81º) during flexion (P=0.03).

CONCLUSION

Knee bending in patients with PAAs will lead to a reduction in the lumen area of the PAA and a change in the degree of angulation of the PAA. A significant decrease in lumen area was seen in PAAs≥30 mm compared with PAAs<30 mm after flexion of the knee.

Appropriateness of antimicrobial therapy: a multicentre prevalence survey in the Netherlands, 2008-2009

A survey was carried out to determine the prevalence and appropriateness of antimicrobial therapy (AMT) in the Netherlands and to identify determinants for inappropriate AMT. Prevalence surveys of patients hospitalised in the Netherlands were performed three times in 2008 and 2009. Patients' demographic, infection-related and AMT-related data were collected from hospital wards. A total of 19 hospitals participated, consisting of a mix of university, teaching and general hospitals, which were distributed evenly across the country. The appropriateness of AMT was assessed using a standardised algorithm based on local AMT prescription guidelines. A total of 7,853 patients were included, of which 2,327 (29.6%) patients were on AMT (range: 20.8–39.5%). In 372 patients (16% of patients on AMT), treatment was considered inappropriate. In 265 (11.4%) patients on AMT, appropriateness of treatment was not judged because of insufficient information. The percentage of patients without a judgment varied considerably between the participating hospitals (range: 1.3–36.2%). Appropriate AMT use was significantly associated with a patient being in an intensive care unit, having a central venous catheter and being given beta-lactamase-sensitive penicillins. The use of fluoroquinolones was significantly associated with more frequent inappropriate use. There was considerable and significant variation between the participating hospitals in the amount of antimicrobials prescribed and the appropriateness of their use. To improve the completeness and reliability of such surveys, there is a need for intensive training of observers and medical staff in recording information.

Vitex agnus castus as prophylaxis for osteopenia after orchidectomy in rats compared with estradiol and testosterone supplementation

Osteoporosis research undertaken in males is rare and there are only a few therapeutic options. Phytoestrogens might be a safe alternative for prophylaxis. Sixty 3-month-old male rats were orchidectomized and divided into five groups. The groups either received soy-free food (C), estradiol (E), testosterone (T) or Vitex agnus castus in different concentrations (AC high/AC low) for 12 weeks. The tibia metaphysis was tested biomechanically and histomorphometrically. The AC high group reached 87% of the biomechanical values of the estradiol group and was significantly superior to the control group. Testosterone supplementation resulted in poor biomechanical properties. The cortical bone parameters of the AC group were similar to the control group, while supplementation with estradiol and testosterone demonstrated a reduction of cortical bone. The AC high group reached 88.4% of trabecular bone area, 80.7% of trabecular number and 66.9% of the number of trabecular nodes compared with estradiol supplementation. Vitex agnus castus demonstrated osteoprotective effects in males. It preserves the cortical as well as the trabecular bone and might be a safe alternative for HRT. Testosterone supplementation has positive effects on trabecular bone, which are concurrently counteracted by the loss of cortical bone.

[Diagnostic image (381). A man with painful, red spots on one foot]

A 49-year-old Turkish man with classic Kaposi sarcoma on his right foot, was successfully treated by irradiation.

[Diagnostic image (378). A woman with a subungual pigmentation of the left hallux]

An 81-year-old woman presented with a subungual pigmented lesion of the left hallux, caused by a malignant acral-lentiginous melanoma.

[Acute compartment syndrome of the foot]

In two patients, a girl aged 2 and a man aged 52 years, who had suffered a severe crush trauma, acute compartment syndrome of the foot was diagnosed. Decompression by means of one medial and two dorsal dermato-fasciotomy incisions was carried out and fractures of the metatarsals were repaired using K-wires. The girl recovered completely, but the man developed progressive necrosis in the flexors of the foot and on the skin on the foot sole which necessitated amputation of the foot. Acute compartment syndrome of the foot is an uncommon disease and is mainly characterised by extreme pain and often diffuse swelling of the foot. It is a serious threat to the foot which can lead to severe long-term complications including contractures, deformity and paralysis. Compartment syndrome of the foot is a primary clinical diagnosis. When in doubt, direct pressure measurement of the foot compartments should be done by means of needle catheterisation. If compartment pressure exceeds 30 mm Hg, acute dermato-fasciotomy of all nine compartments is indicated. A combined medial and dorsal approach is adopted to release the foot compartments; three incisions are usually sufficient. If fractures are present, these are repaired at the same time. Within four hours an unnoticed compartment syndrome can lead to irreversible ischaemia of the nerves and muscle tissue with long-term irreversible consequences.

Ergebnisqualität bei der Maschinellen Autotransfusion und Einflussfaktoren

Also intraoperative blood salvage (IBS) requires a system for quality management with controls of product an process quality. These can help early detection of malfunctions. For proper reaction and for improvement of quality a deep understanding of the process of blood salvage is necessary. This is supported by experimental testing of equipment, programs, and process variables, and by analysis of their effects on the process. The use of fresh whole blood and total protein as wash-out parameter in these tests is superior to outdated banked RBC and free haemoglobin. The process of aspiration turns out much less harmful than expected, when tested with fresh blood. Low wash volumes, fast washing rates, and half full bowls should be avoided. Plasma wash-out is improved by slower washing or by higher wash volumes, but the latter decrease RBC recovery. Such quality management helps to provide blood of excellent quality by IBS for optimal haemotherapy.

Natural carbon isotopes used to study methane consumption and production in soil

Changes in the isotopic composition of carbon can be used to reveal simultaneous occurrence of methane production and oxidation in soil. The method is conducted in laboratory jar experiments as well as in the field by using flux chambers. Simultaneous occurrence of production and oxidation of methane was suggested.

Specificity of endothelial cell reorientation in response to cyclic mechanical stretching

Evidence suggests that cellular responses to mechanical stimuli depend specifically on the type of stimuli imposed. For example, when subjected to fluid shear stress, endothelial cells align along the flow direction. In contrast, in response to cyclic stretching, cells align away from the stretching direction. However, a few aspects of this cell alignment response remain to be clarified: (1) Is the cell alignment due to actual cell reorientation or selective cell detachment? (2) Does the resulting cell alignment represent a response of the cells to elongation or shortening, or both? (3) Does the cell alignment depend on the stretching magnitude or rate, or both? Finally, the role of the actin cytoskeleton and microtubules in the cell alignment response remains unclear. To address these questions, we grew human aortic endothelial cells on deformable silicone membranes and subjected them to three types of cyclic stretching: simple elongation, pure uniaxial stretching and equi-biaxial stretching. Examination of the same cells before and after stretching revealed that they reoriented. Cells subjected to either simple elongation or pure uniaxial stretching reoriented specifically toward the direction of minimal substrate deformation, even though the directions for the two types of stretching differed by only about 20 degrees. At comparable stretching durations, the extent of cell reorientation was more closely related to the stretching magnitude than the stretching rate. The actin cytoskeleton of the endothelial cell subjected to either type of stretching was reorganized into parallel arrays of actin filaments (i.e., stress fibers) aligned in the direction of the minimal substrate deformation. Furthermore, in response to equi-biaxial stretching, the actin cytoskeleton was remodeled into a "tent-like" structure oriented out of the membrane plane-again towards the direction of the minimal substrate deformation. Finally, abolishing microtubules prevented neither the formation of stress fibers nor cell reorientation. Thus, endothelial cells respond very specifically to the type of deformation imposed upon them.

Risk assessment for surgical site infections following total hip and total knee prostheses

The purpose of the study was to assess the relative importance of risk factors for surgical site infections (SSI) following total hip and total knee prostheses in The Netherlands. In the period 1996-99 63 hospitals in The Netherlands registered SSI after 36,629 orthopedic operations. Total hip and total knee prostheses were analyzed in detail. The results of our study showed that a long preoperative stay was a risk factor for deep SSIs after both procedures. A dirty or contaminated wound and a serious systemic condition were risk factors for deep SSIs after total hip prostheses. If post-discharge surveillance was carried out, more SSIs were found, for total knee prostheses more than twice as many. Independent risk factors for SSIs after total hip prostheses were a contaminated/dirty wound and for total knee prostheses a short operation duration. The authors conclude that surveillance of surgical site infections following total hip and total knee prostheses revealed different risk factors for (deep) SSIs.

Pulse oximeter-induced digital injury: frequency rate and possible causative factors

OBJECTIVE

To study the frequency rate of and factors associated with pulse oximeter-induced digital injury (PIDI).

DESIGN

Prospective descriptive study.

SETTING

Surgical intensive care unit of a university hospital.

PATIENTS

All patients with a length of stay of >2 days.

INTERVENTIONS AND MAIN RESULTS

We monitored 125 patients by using a pulse oximeter with a nondisposable clip-on probe changed every 3-4 hrs from one finger to another. Daily inspection was performed with special attention to digital injury. Factors implicated in the pathogenesis of PIDI, such as vasopressor therapy, hypotension, hypoxia, hypothermia, and arterial cannulation of the radial or ulnar artery were recorded daily. A total of 22 patients received norepinephrine and dopamine, 34 patients were given dopamine, and 69 patients did not receive vasoactive drugs. PIDI developed in 6 of 125 patients, five in the norepinephrine/dopamine group, one in the dopamine group, and none in the patients not receiving vasopressors. When comparing the frequency rate of PIDI in patients receiving norepinephrine (5 of 22) with patients not receiving norepinephrine (1 of 103) the relationship between the use of norepinephrine and PIDI is significant (p < .001). However, this relationship may also be explained by the fact that patients in the norepinephrine group were more severely ill than patients not requiring norepinephrine were. This is reflected by a higher median severity of illness score (Simplified Acute Physiology Score II) (p = .001), median duration of hypotension (p < .001), median number of saturation drops (p < .001), and higher mortality rate (p < .001). Hypothermia did not occur in any of the patients. There was no significant difference between the median right-left difference in duration of arterial cannulation between the two subgroups (p = .8). In all surviving patients, PIDI healed without permanent damage.

CONCLUSIONS

In the studied population of critically ill patients in a surgical intensive care unit, the frequency rate of PIDI was 5% (6 of 125). Although an association with the use of norepinephrine was found, this small number of cases does not allow definite statistical conclusions concerning a relationship between the possible causative factors and PIDI. However, severely ill patients, as indicated by their need for more aggressive vasopressors, are more likely to develop PIDI. In survivors, PIDI healed without sequelae.

[Restricting freedom of children and adolescents from the adolescent psychiatry and legal viewpoint]

Recent developments in child and adolescent psychiatry, youth welfare and the law concerning involuntary hospitalisation are discussed. Enforcement of control and coercive measures seems to be inevitable in some of the situations in adolescent psychiatry. The authors therefore recommend an open discussion on compulsory procedures in and between the institutions involved. They present clearcut rules for concerted action that have been jointly developed in their district.

Pressure sores and tube feeding in patients with a fracture of the hip: a randomized clinical trial

Pressure sores are a frequent problem, especially in elderly patients. Nutritional status may influence the incidence, progression and severity of pressure sores, data, however, are contradictory (1). The purpose of this study was to determine the effect of supplemental feeding on the nutritional status and the development and severity of pressure sores. The effect of supplemental feeding overnight (tube +) on patients with a fracture of the hip and a high pressure-sore risk score, was studied in a randomized clinical trial. The control group (tube -) had no supplemental feeding. After informed consent, 140 patients were randomized, and 129 of these took part in the trial (62 tube +, and 67 tube -). Protein and energy intake, haemoglobin, serum albumin, total serum protein and pressure-sore grade were measured at admission and after 1 and 2 weeks. Of the 62 patients randomized for tube feeding (tube +), only 25 tolerated their tube for more than 1 week and 16 for 2 weeks. Nevertheless, energy and protein intake was significantly higher in the tube + group (P < 0.001). This, however, did not significantly influence total serum protein, serum albumin and development and severity of pressure sores after 1 and 2 weeks. Comparison of the actually tube fed group (n=25 at 1 week, n = 16 at 2 weeks) and the control group showed a 2-3 times higher protein and energy intake (P < 0.0001), and a significantly higher total serum protein and serum albumin after 1 and 2 weeks in the actually tube fed group (all P < 0.001). Pressure-sore development and severity were not significantly influenced in the actually tube fed group. We conclude that we were not able to show a significant decrease in development and severity of pressure sores, because the nasogastric tube for supplemental feeding was not well tolerated in this patient group. Nevertheless, tube feeding overnight does result in a significant higher protein and energy intake, and has a significant effect on nutritional status in the actually tube-fed group. Other means of supplemental feeding will have to be used in order to answer the question of whether supplemental feeding can decrease development and severity of pressure sores.

Epidermal expression of collagenase delays wound-healing in transgenic mice

A vital characteristic of skin is its ability for wound repair in response to injury. A transient elevation of matrix metalloproteinases (MMP) in the epidermal and dermal compartments of healing wounds implicates the MMP family of enzymes in the regulation of events important to injury repair. Transgenic mice expressing human interstitial collagenase (MMP-1) in the epidermis were used to perturb the regulation of this proteinase in order to examine the role of epidermal collagenase during wound healing. The relative healing potential of collagenase transgenic mice and wild-type littermates was assessed by measurements of the wound area during closure of full-thickness wounds. Transgenic mice exhibited a 2-3 d delay in the time required to reach 50% closure of 6 mm wounds. Histologic analysis of the transgenic wound bed revealed the retarded migration of the epithelium across the open wound. The results are consistent with the hypothesis that control of collagenase (MMP-1) expression is important for re-epithelialization during wound healing and indicate that collagenase regulation is critical to the kinetics of normal wound closure.

[Palliative treatment of wrist joint metastasis of primary bronchial carcinoma with a dynamic compression plate]

The authors describe a patient with a wrist metastasis of a primary pulmonary carcinoma. Palliative radiotherapy in combination with splinting failed to release the pain. He was then successfully treated by radiocarpal bridging with a dynamic condylar plate.

Arthrodesis of the septic ankle joint

In chronic septic complications of the ankle joint bony fusion can be achieved with radical resection of necrotic tissues, special positioning of the foot and extrafocal stabilisation. For non-cooperative patients with bland infections intramedullary stabilisation can be used after which early full weight bearing is possible. The correct technique of operation together with adjuvant therapy with a Septopal chain increases the healing chances of patients and reduces the time and costs of therapy.

Late results of fractures and pseudoarthroses of the leg after tibiofibular synostosis

The authors present the late results of 10 male patients with open leg fractures and nonunions treated between 1978 and 1985 with tibiofibular synostosis. This was achieved by autologous cancellous bone grafting. The average time of the follow-up study was 11 years at which time all patients were free of fistulas, fully weight-bearing and able to work. In their subjective opinion these advantages compensated for reduced ankle motion and tolerable periodic pain.

Prevention of recurrent infection after removal of intramedullary metal of the infected femur and tibia

Prevention of recurrence after consolidation of infected femur and tibia fractures and nonunions is based on two principles. First necrotic bone is eliminated with reaming and rinsing the intramedullary canal after metal removal. As missing inramedullary tissue granulates gradually, prevention of retention cavities is achieved by a drainage tube that is gradually removed in the direction of gravity. In chronic cases the method is combined with application of a Septopal chain. Since 1978 this method has been used in 39 cases of which 32 have been succesful.

Pressure sores and pressure-decreasing mattresses: controlled clinical trial

Pressure sores are a problem, especially in elderly patients. Our study was designed to determine the effectiveness in pressure-sore prevention of a new interface-pressure decreasing mattress. In a prospective randomised controlled clinical trial we tested the Comfortex DeCube mattress (Comfortex, Winona, USA) against our standard hospital mattress in 44 patients with femoral-neck fracture and concomitant high pressure-sore risk score. In addition both groups were treated according to the Dutch consensus protocol for the prevention of pressure sores. On admission and 1 and 2 weeks after admission, pressure sores were graded. The two groups were similar in patient characteristics and pressure-sore risk factors. At 1 week, 25% of the patients nursed on the DeCube mattress and 64% of the patients nursed on the standard mattress had clinically relevant pressure sores (grade 2 or more). At 2 weeks the figures were 24% and 68%, respectively. The maximum score over the several body regions of the pressure-sore grading, measured on a 5-point sale, was significantly different in favour of the DeCube mattress at 1 week (p = 0.0043) and 2 weeks (p = 0.0067) postoperatively. We show that the occurrence of pressure sores and their severity can be significantly reduced when patients at risk are nursed on an interface-pressure decreasing mattress.

Analysis of the extractive and hydrolytic behavior of microthane poly(ester-urethane) foam by high pressure liquid chromatography

Microthane foam, a poly(ester-urethane) (PU) used in the manufacture of Meme/Replicon breast implants, was analyzed by an HPLC method to determine whether 2,4- and 2,6-toluenediamine (TDA) were formed under a variety of physiological and nonphysiological extraction and hydrolytic conditions. At our detection limit of 20 ppb, no 2,4- or 2,6-TDA was observed in either methyl tert-butyl ether (MTBE), or aqueous buffer extracts of PU foam. The predominant extractable components identified by HPLC UV-analysis, were mixture of nonaromatic and aromatic PU fragments. Moreover, no detectable amounts of TDA were found in foam or MTBE extract of foam incubated in phosphate buffer, pH 7.4, at 37 degrees C for 5 days. By contrast, 2,4- and 2,6-TDA were found in foam and foam extracts exposed to low concentrations of either strong mineral acid or base; higher levels were found at higher acidity, treatment temperature, or durations of incubation. Moreover, 2,4- and 2,6-TDA were found in oligomers isolated by preparative HPLC and exposed to alkaline conditions. Finally, 1-2 ppm of 2,4-TDA was detected when PU foam extracts were prepared by the Snyder-Breder method, which employs acidic and alkaline conditions in the work-up procedure. Based on these findings, we suggest that published observations of 2,4-TDA formation from in vitro and ex vivo extractions of PU foam are artifacts resulting from pH effects on oligomeric PU fragments present in or extracted from the foam.