Hyperechoic kidneys in a patient with bronchiectasis.

INTRODUCTION: Hyperechoic renal cortex in a normal-sized kidney has a range of causes, some of which irreparably damage the kidney and should initiate further investigations. CASE REPORT: We present a 72-year-old woman with longstanding bronchiectasis, noticed to have worsening renal function. Renal tract ultrasonography showed hyperechoic normal-sized kidneys. Renal biopsy confirmed amyloidosis. DISCUSSION: Imaging findings in renal amyloidosis tend to be non-specific and are not always present. However, ultrasonography findings of hyperechoic cortex in normal-sized kidneys should not be ignored. CONCLUSION: Renal impairment from blood chemistry in addition to hyperechoic kidneys may be the key to diagnosing secondary amyloidosis in a patient with bronchiectasis, a rare association but important to recognise.

Acute kidney injury associated with endurance events-is it a cause for concern? A systematic review.

INTRODUCTION: A growing body of evidence suggests even small rises in serum creatinine (SCr) are of considerable clinical relevance. Given that participants in endurance events are exposed to potential (repeated) renal insults, a systematic review was undertaken to collate current evidence for acute kidney injury (AKI), complicating such events. METHODS: A systematic review of studies and case reports meeting inclusion criteria on Medline and EMBASE (inception to October 2015). Included: studies with markers of renal function before and after endurance or ultraendurance events; case reports of severe AKI. Two reviewers assessed risk of bias using the Newcastle-Ottawa scale. RESULTS: Eleven case report publications (n=27 individuals) of severe AKI, were retrieved, with risk factors including systemic illness or nephrotoxic medications usually identified. From 30 studies of endurance and ultraendurance events, mean rise in SCr was 29 (±12.3) µmol/L after marathon or ultramarathon (17 studies, n=568 participants) events. Where follow-up tests were conducted, SCr returned to baseline within 48 hours. Rises in biomarkers suggest potential parenchymal insult, rather than simply muscle breakdown. However, evidence of long-term deleterious effects is lacking. CONCLUSIONS: Raised levels of SCr are reported immediately after endurance events. It is not clear whether this is either clinically significant, or if repeated participation predisposes to long-term sequelae. The aetiology of severe exercise-associated AKI is usually multifactorial, with risk factors generally identified in the rare cases reported. On-site biochemistry, urine analysis and biomarkers of AKI may help identify collapsed runners who are at significant short-term risk and allow suitable follow-up.

Predicting AKI in emergency admissions: an external validation study of the acute kidney injury prediction score (APS).

OBJECTIVES: Hospital-acquired acute kidney injury (HA-AKI) is associated with a high risk of mortality. Prediction models or rules may identify those most at risk of HA-AKI. This study externally validated one of the few clinical prediction rules (CPRs) derived in a general medicine cohort using clinical information and data from an acute hospitals electronic system on admission: the acute kidney injury prediction score (APS). DESIGN, SETTING AND PARTICIPANTS: External validation in a single UK non-specialist acute hospital (2013-2015, 12 554 episodes); four cohorts: adult medical and general surgical populations, with and without a known preadmission baseline serum creatinine (SCr). METHODS: Performance assessed by discrimination using area under the receiver operating characteristic curves (AUCROC) and calibration. RESULTS: HA-AKI incidence within 7 days (kidney disease: improving global outcomes (KDIGO) change in SCr) was 8.1% (n=409) of medical patients with known baseline SCr, 6.6% (n=141) in those without a baseline, 4.9% (n=204) in surgical patients with baseline and 4% (n=49) in those without. Across the four cohorts AUCROC were: medical with known baseline 0.65 (95% CIs 0.62 to 0.67) and no baseline 0.71 (0.67 to 0.75), surgical with baseline 0.66 (0.62 to 0.70) and no baseline 0.68 (0.58 to 0.75). For calibration, in medicine and surgical cohorts with baseline SCr, Hosmer-Lemeshow p values were non-significant, suggesting acceptable calibration. In the medical cohort, at a cut-off of five points on the APS to predict HA-AKI, positive predictive value was 16% (13-18%) and negative predictive value 94% (93-94%). Of medical patients with HA-AKI, those with an APS ≥5 had a significantly increased risk of death (28% vs 18%, OR 1.8 (95% CI 1.1 to 2.9), p=0.015). CONCLUSIONS: On external validation the APS on admission shows moderate discrimination and acceptable calibration to predict HA-AKI and may be useful as a severity marker when HA-AKI occurs. Harnessing linked data from primary care may be one way to achieve more accurate risk prediction.

The effect of magnetic resonance imaging noise on cochlear function in dogs.

Noise produced by magnetic resonance imaging (MRI) scanners (which can peak at a sound pressure level of 131 dB) has been shown to cause noise-induced cochlear dysfunction in people. The aim of this study was to investigate whether noise produced during MRI had a deleterious effect on cochlear function in dogs, using distortion product otoacoustic emission (DPOAE) testing, which allows frequency specific, non-invasive assessment of cochlear function. DPOAE testing was performed before and after MRI in one or both ears under general anaesthesia at 14 frequency pairs (f2 frequency ranging from 0.84 kHz to 8.0 kHz). A control group comprised dogs undergoing anaesthesia of a similar duration for quiet procedures. Thirty-six dogs (66 ears) and 17 dogs (28 ears) were included in the MRI and control groups respectively. There was a reduction in DPOAE at all frequencies tested in the MRI group; a similar effect was not evident in the control group. This reduction in the MRI group was statistically significant in five of the 14 frequencies assessed (P < 0.05). These results demonstrate that exposure to MRI noise results in a significant reduction in frequency-specific cochlear function in dogs, although it is not known whether this is reversible or permanent. This suggests that all dogs undergoing MRI studies should be provided with ear protection as a routine precautionary measure.

Introduction of an electronic physiological early warning system: effects on mortality and length of stay.

BACKGROUND: The Worthing physiological scoring system (PSS) was first validated in 2005 as a tool to predict hospital mortality on admission and was subsequently introduced into clinical practice at Worthing Hospital, UK. Five years on, this study was conducted to determine the effects on mortality and length of stay (LOS) after the introduction of electronic alerting software using the PSS. In addition, we investigated whether the Worthing PSS predictive ability could be improved by addition of further variables. METHODS: Prospective observational study conducted in the acute medical unit, Worthing Hospital, UK. Patient physiological data on admission and discharge/transfer were collected between February and July 2010 from the electronic alerting software VitalPAC™. Patient characteristics, co-morbidity, outcomes, and biochemistry data were taken from the hospital administration and pathology systems. RESULTS: The observed mortality reduction from 8.3% to 5.2% over 5 yr was not statistically significant after adjustment for admission Worthing PSS score. Median LOS was reduced from 4 to 2 days, but this reflected an increase in short stay admissions. Worthing PSS was not significantly improved with the addition of biochemical variables or patient co-morbidity. A score taken before admission to a medical ward showed an improved predictive ability when compared with the initial admission score, but further analysis found no additional clinical benefit. CONCLUSIONS: The introduction of an electronic alerting PSS did not lead to a reduction in mortality when adjusted for severity of illness defined by physiological variables. Predictive performance was not enhanced by the addition of biochemical variables and co-morbidities.

Co-induction of anaesthesia with 0.75 mg kg propofol followed by sevoflurane: a randomized trial in the elderly with cardiovascular risk factors.

BACKGROUND: The induction of general anaesthesia is associated with the greatest cardiovascular changes in elderly patients. Induction can be performed either intravenously or with gaseous induction. Sevoflurane has advantages over propofol for induction of anaesthesia in the elderly, since the lower reduction in mean arterial pressure with sevoflurane is both statistically and clinically significant. This prospective randomized controlled trial investigated the cardiovascular benefits of co-induction of anaesthesia with 0.75 mg kg(-1) propofol and 8% sevoflurane, when compared with 8% sevoflurane alone in patients requiring surgery for fractured neck of femur. METHOD: In total, 38 patients aged 75 or over were allocated into the two groups, receiving either 0.75 mg kg(-1) of propofol followed by 8% sevoflurane or 8% sevoflurane alone. Vital signs were recorded until successful insertion of a laryngeal mask. Induction times, induction events and patient satisfaction scores were also recorded. RESULTS: Results showed that there were no differences in the cardiovascular parameters between the two groups. Induction times were faster in the propofol and sevoflurane group (62 vs. 81 s; P = 0.028). The postoperative questionnaire showed that the majority of patients in both groups were satisfied with the induction process. CONCLUSIONS: We concluded that 0.75 mg kg(-1) of propofol followed by sevoflurane induction is an acceptable alternative to sevoflurane induction. It is associated with similar haemodynamic variables, faster induction times and is very well tolerated.

Worthing physiological scoring system: derivation and validation of a physiological early-warning system for medical admissions. An observational, population-based single-centre study.

BACKGROUND: Several physiological scoring systems (PSS) have been proposed for identifying those at risk of deterioration. However, the chosen specific physiological values chosen and the scores allocated have not been prospectively validated. In this study, we investigate the relative contributions of the ventilatory frequency, heart rate, arterial pressure, temperature, oxygen saturation, and conscious level to mortality in order to devise a robust scoring system. All data were collected on admission to the emergency unit. Precise 'intervention-calling scores' could then be derived to trigger interventions. METHODS: Our observational, population-based single-centred study took place in a 602-bedded district general hospital. Patients admitted to the emergency care unit at Worthing general hospital during an initial study period between July and November 2003 (n = 3184) and a further validation period between October and November 2005 (n = 1102) were included. RESULTS: Multivariate logistic regression analysis demonstrated that a ventilatory frequency > or = 20 min(-1), heart rate > or =102 min(-1), systolic blood pressure < or = 99 mm Hg, temperature <35.3 degrees C, oxygen saturation < or = 96%, and disturbed consciousness were associated with an increase in mortality. The Worthing PSS was developed from the regression coefficients associated with each variable. The model showed good discrimination with an area under the receiver operating characteristic curve, 0.74, excluding age as a variable. The discrimination of this system was significantly better than the early-warning scoring system. CONCLUSIONS: A simple validated scoring system to predict mortality in medical patients with precise 'intervention-calling scores' has been developed.

The efficacy of intra-articular bupivacaine for relief of pain following arthroscopy of the ankle.

The intra-articular injection of local anaesthetic is frequently used for pain relief after arthroscopy. There is, however, no published evidence of the analgesic effect of bupivacaine in the ankle. In a randomised, double-blind study, 35 patients undergoing arthroscopy of the ankle were allocated to receive intra-articular saline or bupivacaine. Pain was assessed using pain scores and additional analgesic requirements. Intra-articular bupivacaine had a significant analgesic effect in the immediate post-operative period, reducing pain scores and the need for additional analgesics. We recommend the use of intra-articular bupivacaine for post-operative analgesia in ankle surgery.

Identifying the sick: can biochemical measurements be used to aid decision making on presentation to the accident and emergency department.

BACKGROUND: Early and accurate identification of patients who may benefit from aggressive optimal medical intervention is essential if improved outcomes in terms of survival are to be achieved. We studied the usefulness of routine clinical measurements and/or markers of metabolic abnormality in the early identification of those patients at greatest risk of deterioration on presentation to the accident and emergency department. METHODS: We conducted a prospective observational study in the accident and emergency department of a 602-bed district general hospital. Routine clinical measurements (heart rate, systolic blood pressure, temperature, oxygen saturation in room air, level of consciousness and ventilatory frequency) and venous blood analysis for metabolic markers (pH, bicarbonate, standard base excess, lactate, anion gap, strong ion difference, and strong ion gap) and biochemical markers (Na+, K+, Ca2+, Cl-, PO4- albumin, urea and creatinine) were recorded from unselected consecutive hospital admissions over two 3-month periods (September-November 2002 and February-April 2003). RESULTS: Logistic regression analysis showed that neither conventional clinical measurements upon presentation to the accident and emergency department nor venous biochemical and metabolic indices have good discriminatory ability when used as single predictors of either hospital mortality or length of hospital stay. Selecting variables from all the clinical and venous blood measurements gave a parsimonious model containing only age, heart rate, phosphate and albumin (area under the receiver operating characteristic curve, 0.82 [95% CI 0.76, 0.87]). CONCLUSIONS: A combination of clinical and venous biochemical measurements in the accident and emergency department proved the best predictors of hospital mortality. Consequently, they may be helpful as a triage tool in the accident and emergency department to help identify patients at risk of deterioration.

Molecularly imprinted polymers for the determination of a pharmaceutical development compound in plasma using 96-well MISPE technology.

The use of molecularly imprinted polymers (MIPs) as sorbents for the solid phase extraction (SPE) of a pharmaceutical compound in development, prior to quantitative analysis was investigated. Three MIPs were synthesised using a structural analogue as the template molecule. Each polymer was prepared with different monomers and porogens. The MIPs were then tested for their performance both in organic and aqueous environments, the final aim being to load plasma directly onto the polymers. At an early development stage, there is a limited amount of compound available. Due to this limitation, reducing the amount of template required for imprinting was investigated. A MIP capable of extracting the analyte directly from plasma was produced. The specificity of the polymer allowed the method to be validated at a lower sensitivity than a more conventional SPE assay. For the first time, MIPs were packed into 96-well blocks enabling high throughput analysis. The analytical method was fully validated for imprecision and inaccuracy down to 4 ng/ml in plasma.

Perioperative fluid volume optimization following proximal femoral fracture.

BACKGROUND: Proximal Femoral Fracture (PFF) or 'hip fracture' is a frequent injury, and adverse outcomes are common. Several factors suggest the importance of developing techniques to optimize intravascular fluid volume. These may include protocols that enhance the efficacy of clinicians' assessments, invasive techniques such as oesophageal Doppler or central venous pressure monitoring, or advanced non-invasive techniques such as plethysmographic pulse volume determination. OBJECTIVES: To determine the optimal method of fluid volume optimization for adult patients undergoing surgical repair of PFF. Comparisons of fluid types, of blood transfusion strategies or of pharmacological interventions are not considered in this review. SEARCH STRATEGY: We searched CENTRAL (The Cochrane Library, issue 4, 2003), MEDLINE (1985 to 2003), EMBASE (1985 to 2003), and bibliographies of retrieved articles. Relevant journals and conference proceedings were handsearched. SELECTION CRITERIA: Randomized controlled studies comparing a fluid optimization intervention with normal practice or with another fluid optimization intervention, in patients following PFF undergoing surgery of any type under anaesthesia of any type. DATA COLLECTION AND ANALYSIS: Searches and exclusion of clearly irrelevant articles were performed by one reviewer. Two reviewers examined independently the remaining studies, extracting study quality and results data. A wide range of short- and long-term outcome data were sought. Studies were excluded if they did not meet selection criteria or if results were likely to be biased. Due to inconsistent data reporting, combination of data was not generally possible. MAIN RESULTS: Searches identified four trials, of which two studies, randomizing a total of 130 patients, were of adequate quality and addressed the review question. Both studies were of invasive advanced haemodynamic monitoring, either oesophageal Doppler ultrasonography or central venous pressure monitoring, during the intraoperative period only. In both, invasive monitoring led to significant increases in fluid volumes infused and reductions in length of hospital stay. The pooled Peto odds ratio for in-hospital fatality was 1.44 (95% confidence interval 0.45-4.62). Neither study followed patients beyond hospital discharge or assessed functional outcomes. No serious complications were directly attributable to the interventions. There were no studies of protocol-guided fluid optimization or of advanced non-invasive techniques. REVIEWER'S CONCLUSIONS: Invasive methods of fluid optimization during surgery may shorten hospital stay, but their effects on other important, patient-centred, longer-term outcomes are uncertain. Adverse effects on fatality cannot be excluded. Other fluid optimization techniques have not been evaluated. The lack of randomized studies of adequate quality addressing this important question is disappointing. More research is needed.

Pharmacokinetics of dexmedetomidine infusions for sedation of postoperative patients requiring intensive caret.

BACKGROUND: The pharmacokinetics of the alpha-2 adrenoceptor agonist dexmedetomidine were studied in 10 patients requiring postoperative sedation and mechanical ventilation in the intensive care unit (ICU), and compared with previous volunteer data. METHODS: On arrival in the ICU, sedation with dexmedetomidine was commenced with a loading dose of 2.5 microg kg(-1) h(-1) over 10 min followed by a maintenance infusion of 0.7 microg kg(-1) h(-1) into a central vein. Blood samples for measurement of plasma dexmedetomidine concentrations were taken during and after sedative infusions at predetermined intervals. Pharmacokinetic variables were estimated using non-compartmental methods. In addition, non-linear mixed effects modelling was used to obtain variable estimates not readily attainable from non-compartmental methods. Respiratory and haemodynamic data were recorded to enable correlation of any adverse events with the calculated pharmacokinetic profile. RESULTS: The harmonic mean distribution half-life of dexmedetomidine was 8.6 min and the harmonic mean terminal half-life was 3.14 h. Steady-state volume of distribution averaged 173 litres, clearance averaged 48.3 litres h(-1), and the mean residence time averaged 3.86 h. CONCLUSIONS: Mean dexmedetomidine pharmacokinetic variables seen in postoperative, intensive care patients were similar to those previously found in volunteers, with the exception of the steady-state volume of distribution. A small loading dose provided effective sedation with no adverse events.

Randomized controlled trial to investigate influence of the fluid challenge on duration of hospital stay and perioperative morbidity in patients with hip fractures.

BACKGROUND: A prospective, randomized controlled trial comparing conventional intraoperative fluid management with two differing methods of invasive haemodynamic monitoring to optimize intraoperative fluid therapy, in patients undergoing proximal femoral fracture repair under general anaesthesia. METHODS: Ninety patients randomized to three groups; conventional intraoperative fluid management (Gp CON, n=29), and two groups receiving additional repeated colloid fluid challenges guided by central venous pressure (Gp CVP, n=31) or oesophageal Doppler ultrasonography (Gp DOP, n=30). Primary outcome measures were time to medical fitness to discharge, hospital stay and postoperative morbidity. RESULTS: The fluid challenge resulted in significantly greater perioperative changes in central venous pressure between Gp CVP and Gp CON (mean 5 (95% confidence interval 3-7) mm Hg) (P<0.0001). Important perioperative changes were also shown in Gp DOP with increases of 49.4 ms (19.7-79.1 ms) in the corrected flow time, 13.5 ml (7.4-19.6 ml) in stroke volume, and 0.9 (0.49-1.39) litre min(-1) in cardiac output. As a result, fewer patients in Gp CVP and Gp DOP experienced severe intraoperative hypotension (Gp CON 28% (8/29), Gp CVP 9% (3/31), Gp DOP 7% (2/30), P=0.048 (chi-squared, 2 degrees of freedom (df). No differences were seen between the three groups when major morbidity and mortality were combined, P=0.24 (chi-squared, 2 df). Postoperative recovery for survivors, as defined by time to be deemed medically fit for discharge, was significantly faster, in comparison with Gp CON, in both the Gp CVP (10 vs 14 (95% confidence interval 8-12 vs 12-17) days, P=0.008 (t-test)), and Gp DOP (8 vs 14 (95% confidence interval 6-12 vs 12-17) days, P=0.023 (t-test). There were no significant differences between groups, for survivors, with respect to acute orthopaedic hospital and total hospital stay. CONCLUSIONS: Invasive intraoperative haemodynamic monitoring with fluid challenges during repair of femoral fracture under general anaesthetic shortens time to being medically fit for discharge.