Symmetric dimethylarginine values in koalas (Phascolarctos cinereus) based on oxalate nephrosis status.

Oxalate nephrosis is a prevalent renal disease in koalas (Phascolarctos cinereus) of the Mount Lofty Ranges population in South Australia. The symmetric dimethylarginine (SDMA) assay is widely used in companion animals to diagnose renal disease, particularly in the early stages. This study aimed to determine: (1) reference intervals for SDMA in koalas and (2) SDMA values of koalas with oxalate nephrosis. Blood samples were collected from 41 Mount Lofty Ranges koalas euthanased on welfare grounds. Koalas were necropsied and, based on renal histopathology, were classified as unaffected (n = 22) or affected (n = 19) by oxalate nephrosis. Serum or plasma samples were analysed for creatinine, urea and SDMA and urine samples for urine specific gravity (USG). The reference interval for SDMA in unaffected koalas was 2.4-22.9 µg/dL. In koalas with oxalate nephrosis, SDMA was elevated in 74% of cases above the upper limit of the confidence interval. SDMA was elevated in three affected koalas with normal creatinine values. A positive correlation was found between SDMA and creatinine (R = 0.775, P < 0.001) and SDMA and urea (R = 0.580, P < 0.001) and a negative correlation between SDMA and USG (R = -0.495, P = 0.027). In conclusion, SDMA correlates well with other commonly used tests of renal function in koalas and should be included as part of the standard diagnostic process to increase the accuracy of oxalate nephrosis diagnosis in koalas.

International Society of Cardiovascular Infectious Diseases Guidelines for the Diagnosis, Treatment and Prevention of Disseminated Mycobacterium chimaera Infection Following Cardiac Surgery with Cardiopulmonary Bypass.

Mycobacterial infection-related morbidity and mortality in patients following cardiopulmonary bypass surgery is high and there is a growing need for a consensus-based expert opinion to provide international guidance for diagnosing, preventing and treating in these patients. In this document the International Society for Cardiovascular Infectious Diseases (ISCVID) covers aspects of prevention (field of hospital epidemiology), clinical management (infectious disease specialists, cardiac surgeons, ophthalmologists, others), laboratory diagnostics (microbiologists, molecular diagnostics), device management (perfusionists, cardiac surgeons) and public health aspects.

Mycobacterium chimaera infection following cardiac surgery in the United Kingdom: clinical features and outcome of the first 30 cases.

OBJECTIVES: Mycobacterium chimaera infection following cardiac surgery, due to contaminated cardiopulmonary bypass heater-cooler units, has been reported worldwide. However, the spectrum of clinical disease remains poorly understood. To address this, we report the clinical and laboratory features, treatment and outcome of the first 30 UK cases. METHODS: Case note review was performed for cases identified retrospectively through outbreak investigations and prospectively through ongoing surveillance. Case definition was Mycobacterium chimaera detected in any clinical specimen, history of cardiothoracic surgery with cardiopulmonary bypass, and compatible clinical presentation. RESULTS: Thirty patients were identified (28 with prosthetic material) exhibiting a spectrum of disease including prosthetic valve endocarditis (14/30), sternal wound infection (2/30), aortic graft infection (4/30) and disseminated (non-cardiac) disease (10/30). Patients presented a median of 14 months post surgery (maximum 5 years) most commonly complaining of fever and weight loss. Investigations frequently revealed lymphopenia, thrombocytopenia, liver cholestasis and non-necrotizing granulomatous inflammation. Diagnostic sensitivity for a single mycobacterial blood culture was 68% but increased if multiple samples were sent. In all, 27 patients started macrolide-based combination treatment and 14 had further surgery. To date, 18 patients have died (60%) a median of 30 months (interquartile range 20-39 months) after initial surgery. Survival analysis identified younger age, mitral valve surgery, mechanical valve replacement, higher serum sodium concentration and lower C-reactive protein as factors associated with better survival. CONCLUSIONS: Mycobacterium chimaera infection following cardiac surgery is associated with a wide spectrum of disease. The diagnosis should be considered in all patients who develop an unexplained illness following cardiac surgery.

Limbic encephalitis secondary to HIV seroconversion.

We present a case of acute limbic encephalitis secondary to HIV seroconversion. The patient made a gradual neurological recovery following treatment with antiretroviral therapy, steroids and intravenous immunoglobulin.

Chest radiography findings in adults with pandemic H1N1 2009 influenza.

The current pandemic of a novel influenza A (H1N1) virus, commonly referred to as "swine flu", began in Mexico in March 2009 and reached the UK in April 2009. By 21 July 2009, more than 850 suspected cases of influenza had been seen at Birmingham Heartlands Hospital (BHH), including 52 adults with laboratory-confirmed pandemic H1N1 influenza who were admitted. Of seven patients (13%) requiring intensive care, six needed mechanical ventilation, two needed extra-corporeal membrane oxygenation (ECMO) and one died. Of the 52 admitted adults, 42 (81%) had respiratory symptoms or signs and positive PCR tests for novel Influenza A (H1N1) virus. These patients also had chest radiographs (CXR) taken, which were abnormal for 12 patients (29%). Of these, six patients had bilateral consolidation, which was bibasal in three and widespread in three; all six had pleural effusions. A further six patients had unilateral consolidation with predominantly basal changes; one of these patients had a pleural effusion. The odds ratio for requiring intubation and ventilation with H1N1 influenza and an abnormal CXR was 29.0 (95% confidence interval 2.93-287.0). CXR changes were not common in swine flu, but a significant minority of those requiring admission had consolidation on their CXR. Those who required admission and had CXR changes are more likely to require intubation and ventilation than those without abnormalities on CXR.

Serum lactate and base deficit as predictors of mortality after ruptured abdominal aortic aneurysm repair.

OBJECTIVE: Whole body hypoperfusion and lower torso ischaemia-reperfusion contribute to post-operative organ dysfunction in patients undergoing repair of ruptured abdominal aortic aneurysm (AAA). Serum lactate and base deficit are markers of tissue ischaemia and are used to assess the adequacy of resuscitation. This study examines the prognostic value of immediate post-operative levels of serum lactate and base deficit in ruptured AAA. METHODS: Thirty patients (24 men and 6 women of median age 74, range 51-85, years) who survived to at least 12h after ruptured AAA repair were studied retrospectively. The relationship between immediate post-operative lactate, base deficit and mortality was determined. RESULTS: Fifteen patients (50%) died, all from organ failure. An elevated lactate (>2.1 mmol/l) and base deficit (<-2 mmol/l) were present in 20 (67%) and 27 (90%) patients, respectively. Lactate (p<0.001) and base deficit (p=0.003) were significantly higher in non-survivors compared with survivors. Lactate (p=0.021) and base deficit levels (p=0.028) were independently significant for predicting mortality and a significant interaction existed between lactate and base deficit levels for predicting mortality (p=0.027). The sensitivity and specificity of lactate > or =4.0 mmol/l was 13 of 15 (87%) and 12 of 15 (80%), respectively, and base deficit < or =-7 mmol/l was 12 of 15 (80%) and 12 of 15 (80%), respectively. The likelihood ratios for a positive result with the defined cut-off values for lactate and base deficit were 4.3 and 4.0, respectively. Lactate > or =4.0 mmol/l and base deficit or =-7 mmol/l were associated with a 4% probability of death. CONCLUSION: These data demonstrate that an immediate post-operative serum lactate > or =4.0 mmol/l and base deficit < or =-7 mmol/l are good predictors of outcome after ruptured AAA repair. The prognostic value of these simple and inexpensive tests require corroboration in a larger prospective study.

The acquisition of methicillin-resistant Staphylococcus aureus (MRSA) in vascular patients.

OBJECTIVE: the aim of this study was to establish at which point during a hospital admission MRSA acquisition occurs in vascular patients. METHOD: a consecutive series of 100 patients undergoing arterial surgery were screened for MRSA carriage on admission to hospital, on exit from theatre, on discharge from ITU, weekly whilst an inpatient and on hospital discharge. Screening was with moistened swabs from nose, throat, perineum and open wounds that were pooled for microbiological culture. RESULTS: four patients (4%) screened positive for MRSA on admission to hospital. Of the remaining 96, 16 (17%) acquired MRSA during their hospital stay as follows: exit from theatre, one; exit from ITU, six; on the ward postoperatively, nine. Comparing MRSA acquisition (n=16) with non acquisition (n = 80) the following characteristics were noted, length of stay 16 (4-66) vs 7 (2-50) days (Mann-Whitney p < 0.001); admission to ITU 13/16 vs 46/80 (Fishers chi-squared p = 0.10); length of ITU stay 3 (1-20) vs 3 (1-14) days (Mann-Whitney p = 0.41). Frequent hospital attendance, age, emergency admission, diabetes or renal failure were not commoner in those with MRSA acquisition. CONCLUSIONS: these data indicate that 4% of patients undergoing arterial surgery are pre-existing carriers of MRSA. Length of hospital stay is the single most important determinant of MRSA acquisition.

Studies of a new multi-layer compression bandage for the treatment of venous ulceration.

This study aimed to develop an alternative graduated compression bandage for the treatment of venous leg ulcers. Alternative bandage components were identified and assessed for optimal performance as a graduated multi-layer compression bandage. Subsequently the physical characteristics and clinical efficacy of the optimal bandage combination was prospectively examined. Ten healthy limbs were used to develop the optimal combination and 20 limbs with venous ulceration to compare the physical properties of the two bandage types. Subsequently 42 consecutive ulcerated limbs were prospectively treated to examine the efficacy of the new bandage combination. The new combination produced graduated median (range) sub-bandage pressures (mmHg) as follows: ankle 59 (42-100), calf 36 (27-67) and knee 35 (16-67). Over a seven-day period this combination maintained a comparable level of compression with the Charing Cross system, and achieved an overall healing rate at one year of 88%. The described combination should be brought to the attention of healthcare professionals treating venous ulcers as a possible alternative to other forms of multi-layer graduated compression bandages pending prospective, randomised clinical trials.

A clinical and haemodynamic investigation into the role of calf perforating vein surgery in patients with venous ulceration and deep venous incompetence.

OBJECTIVE: To determine the clinical efficacy and local haemodynamic effects of perforating vein surgery in ulcerated limbs with combined deep and perforating vein incompetence. DESIGN: Prospective, interventional study. MATERIALS AND METHODS: Seven ulcerated limbs with combined primary deep and perforating vein incompetence were studied. Clinical efficacy was determined by ultimate ulcer healing and reduction in ulcer area, local haemodynamics were assessed at three sites with photoplethysmographic 90% venous refilling times (PPG RT90); both assessments were performed pre- and 1-month postoperatively. RESULTS: None of the ulcers healed following perforating vein surgery, the median (range) ulcer areas pre- and postoperatively were 31 (7-685) cm2 and 35.5 (7-796) cm2 (Wilcoxon p = 0.07). Preoperative PPG RT90 demonstrated a global abnormality of venous function at all sites examined that persisted after perforating vein surgery. CONCLUSION: In the presence of deep venous incompetence perforating vein surgery had no influence on venous function or ulcer healing. We conclude that perforating vein surgery is not indicated for the treatment of venous ulceration in limbs with primary deep venous incompetence.

A prospective randomised trial of four-layer versus short stretch compression bandages for the treatment of venous leg ulcers.

This trial was undertaken to examine the safety and efficacy of four-layer compared with short stretch compression bandages for the treatment of venous leg ulcers within the confines of a prospective, randomised, ethically approved trial. Fifty-three patients were recruited from a dedicated venous ulcer assessment clinic and their individual ulcerated limbs were randomised to receive either a four-layer bandage (FLB)(n = 32) or a short stretch bandage (SSB)(n = 32). The endpoint was a completely healed ulcer. However, if after 12 weeks of compression therapy no healing had been achieved, that limb was withdrawn from the study and deemed to have failed to heal with the prescribed bandage. Leg volume was measured using the multiple disc model at the first bandaging visit, 4 weeks later, and on ulcer healing. Complications arising during the study were recorded. Data from all limbs were analysed on an intention to treat basis; thus the three limbs not completing the protocol were included in the analysis. Of the 53 patients, 50 completed the protocol. At 1 year the healing rate was FLB 55% and SSB 57% (chi 2 = 0.0, df = 1, P = 1.0). Limbs in the FLB arm of the study sustained one minor complication, whereas SSB limbs sustained four significant complications. Leg volumes reduced significantly after 4 weeks of compression, but subsequent volume changes were insignificant. Ulcer healing rates were not influenced by the presence of deep venous reflux, post-thrombotic deep vein changes nor by ulcer duration. Although larger ulcers took longer to heal, the overall healing rates for large (> 10 cm2) and small (10 cm2 or less) ulcers were comparable. Four-layer and short stretch bandages were equally efficacious in healing venous ulcers independent of pattern of venous reflux, ulcer area or duration. FLB limbs sustained fewer complications than SSB.

Role of saphenous vein surgery in the treatment of venous ulceration.

BACKGROUND: This paper describes local anaesthetic saphenous disconnection in elderly patients for the treatment of venous ulceration in legs with either saphenous venous reflux alone or in combination with deep venous reflux. METHODS: Ambulatory venous pressure was measured in 16 legs with saphenous vein reflux alone and in nine legs with combined deep and saphenous venous reflux before, immediately after and 3 months after saphenofemoral or popliteal disconnection. Ulcer area was measured by computerized planimetry before surgery and at 1 and 3 months after operation. No compression bandages or hose were applied after surgery unless the ulcers had not begun to heal after 1 month. RESULTS: In legs with saphenous reflux alone all ulcers healed without compression bandages at a median of 81 (range 14-253) days and the pressure relief index (PRI) improved significantly both after surgery and at follow-up. None of the ulcers in the nine limbs with saphenous and deep venous reflux healed without compression bandaging and the PRI was unchanged immediately following surgery and at follow-up. CONCLUSION: Saphenous vein disconnection improves venous function and heals venous ulcers without compression bandaging if the deep veins are normal. This procedure under local anaesthetic may be particularly suitable for elderly patients, but long saphenous vein stripping should be added in young patients.

Single-visit venous ulcer assessment clinic: the first year.

BACKGROUND: Venous ulceration is a significant clinical problem to both clinicians and patients. To optimize the management of patients with ulcers a single-visit, dedicated venous ulcer assessment clinic was set up. METHODS: All patients referred to the clinic during the first year were recorded prospectively. Each patient was assessed clinically and with colour-coded venous and, where indicated, arterial duplex scanning. Ulcers were classified as venous, arterial, mixed or non-vascular on a basis of ankle:brachial pressure indices and venous duplex scanning. RESULTS: Eighty-eight patients (104 limbs with ulcers) were assessed. Seventy-nine per cent of ulcers were venous, 2 per cent arterial, 12 per cent mixed and 7 per cent non-vascular. Of the 95 limbs with demonstrable venous reflux, reflux was confined to the superficial system in 57 per cent, the deep system in 6 per cent and was combined in 37 per cent of limbs. Of the 22 patients who reported previous deep vein thrombosis, nine had normal deep vein function. Some 38 per cent of limbs with no history of previous thrombosis had abnormal deep vein function. CONCLUSION: In this clinic 14 per cent of leg ulcers had a significant arterial component and over half of venous ulcers may benefit from superficial venous surgery. In many ulcerated limbs, clinical assessment alone is inadequate to detect superficial reflux or previous deep vein thrombosis.

Multiple small bowel perforations in a patient on treatment of tuberculosis.

Perforation and obstruction of the small intestine are well recognized in cases of ulcero-constrictive gastro-intestinal tuberculosis and at the commencement of anti-tuberculous chemotherapy. We present a case of two metachronous perforations in a patient despite established anti-tuberculous treatment.