Management of post-operative acute kidney injury.

Post-operative acute kidney injury (AKI) is a common complication of surgery with significant short- and long-term adverse consequences. The adoption of diagnostic criteria for AKI (RIFLE, AKIN and KDIGO) has facilitated comparison of data reported by different centres, confirming that even mild AKI is associated with excess mortality. It remains unclear whether this is caused by the kidney injury itself or whether AKI is simply a marker of underlying disease severity. There is no trial evidence to support the use of any specific therapeutic intervention in post-operative AKI. Best current treatment is, therefore, preventative by optimizing hydration and avoidance of nephrotoxins, emphasizing the importance of earlier detection and identification of individuals at high risk for AKI. In this review, we examine the latest literature on the management of post-operative AKI in adult patients, specifically the diagnosis and definition of AKI, epidemiology and pathogenesis and risk stratification in cardiac and non-cardiac surgery. We also review the latest evidence on pharmacological and non-pharmacological interventions.

Iterative reconstruction and individualized automatic tube current selection reduce radiation dose while maintaining image quality in 320-multidetector computed tomography coronary angiography.

AIM: To assess the effect of two iterative reconstruction algorithms (AIDR and AIDR3D) and individualized automatic tube current selection on radiation dose and image quality in computed tomography coronary angiography (CTCA). MATERIALS AND METHODS: In a single-centre cohort study, 942 patients underwent electrocardiogram-gated CTCA using a 320-multidetector CT system. Images from group 1 (n = 228) were reconstructed with a filtered back projection algorithm (Quantum Denoising Software, QDS+). Iterative reconstruction was used for group 2 (AIDR, n = 379) and group 3 (AIDR3D, n = 335). Tube current was selected based on body mass index (BMI) for groups 1 and 2, and selected automatically based on scout image attenuation for group 3. Subjective image quality was graded on a four-point scale (1 = excellent, 4 = non-diagnostic). RESULTS: There were no differences in age (p = 0.975), body mass index (p = 0.435), or heart rate (p = 0.746) between the groups. Image quality improved with iterative reconstruction and automatic tube current selection [1.3 (95% confidence intervals (CI): 1.2-1.4), 1.2 (1.1-1.2) and 1.1 (1-1.2) respectively; p < 0.001] and radiation dose decreased [274 (260-290), 242 (230-253) and 168 (156-180) mGy cm, respectively; p < 0.001]. CONCLUSION: The application of the latest iterative reconstruction algorithm and individualized automatic tube current selection can substantially reduce radiation dose whilst improving image quality in CTCA.

Trends in pathogens colonising the respiratory tract of adult patients with cystic fibrosis, 1985-2005.

INTRODUCTION: The treatment of patients with CF has continued to evolve. We hypothesised that sputum microbiology may have changed as a result of this. METHOD: Retrospective analysis of sputum microbiology from adult CF patients (1985 to 2005) using the Royal Brompton Hospital CF database. RESULTS: Colonisation with Pseudomonas aeruginosa or Staphylococcus aureus between 1985 and 2005 remained stable (77 to 82%, p=0.159; 54 to 47%, p=0.108; respectively). Haemophilus influenzae (48 to 6%; p<0.001), Aspergillus species (18 to 9%; p=0.002) and Burkholderia cepacia complex (9 to 4%; p=0.041) prevalence decreased. Stenotrophomonas maltophilia and MRSA increased (1 to 4%, p=0.02; 1 to 6%, p=0.002, respectively). CONCLUSION: P. aeruginosa colonisation has remained stable; there has been a decline in B. cepacia complex, H. influenzae and Aspergillus sp., and only a small increase in S. maltophilia and MRSA. Intensive antibiotic strategies have been employed, which, so far, have not resulted in clinically significant emergence of new pathogens.

Gum elastic bougie, capnography and apnoeic oxygenation.

BACKGROUND AND AIM: This study assessed the accuracy of using capnography with a modified, hollow gum elastic bougie in predicting tracheal intubation, and its effectiveness as a method of apnoeic oxygenation. METHODS: Patients were randomly allocated to having the gum elastic bougie inserted, under anaesthesia, in the trachea or the oesophagus. End-tidal carbon dioxide measurements were made at 10 and 20 s. The position of the gum elastic bougie was correctly predicted in 89.2% of patients. We tested the apnoeic oxygenation on an anaesthetic simulator model, which is housed in the Scottish Anaesthesia Simulator Centre, Stirling, UK. RESULTS: The time taken for the oxygen saturation to fall to 90% was significantly prolonged when the gum elastic bougie was used for apnoeic oxygenation. CONCLUSION: The modification of the gum elastic bougie allows a more objective assessment of correct placement than the previous tactile method. The current design of bougie is unsuitable but can be modified.

The effect of glossopharyngeal nerve block on pain after elective adult tonsillectomy and uvulopalatoplasty.

This controlled, randomised, double-blind study compared whether glossopharyngeal nerve block and intravenous morphine administered peri-operatively, decreased pain following elective adult tonsillectomy and uvulopalatoplasty more than morphine alone. Sixteen of 30 patients undergoing uvulopalatoplasty and 38 of 78 patients having tonsillectomy received bilateral glossopharyngeal nerve blocks, using bupivacaine 0.5% and adrenaline 1:200,000, or no intervention. There were no differences in postoperative analgesic consumption between the two groups. Visual analogue pain scores measured during swallowing in the recovery room and on the ward postoperatively were significantly less overall in uvulopalatoplasty patients who had received a block (p = 0.004). This difference was not found for tonsillectomy. We found no significant differences between groups, in pain scores recorded during the first 5 days at home. We conclude that glossopharyngeal block does not improve analgesia following tonsillectomy although there is short-lived benefit following uvulopalatoplasty.

Hemostasis-altering drugs and central neural block. A survey of anesthetic practice in Scotland and the United Kingdom.

BACKGROUND AND OBJECTIVES: There is debate regarding the use of central neural block in the presence of hemostasis-altering drugs. This study aims to examine current practice. METHODS: A survey was made of the members of the Scottish Society of Anaesthetists and the U.K. branch of the European Society of Regional Anaesthesia to determine the pattern of use of central neural block in patients who are receiving drugs known to alter hemostasis. RESULTS: Spinal anesthetics were considered safer than single epidural injections (P < .05) and single epidural injections safer than infusions via epidural catheters (P < .05). CONCLUSIONS: There is general agreement regarding contraindication of central neural block in the presence of full anticoagulation with either heparin or warfarin, but there is less consensus about the use of central neural block in the presence of low-dose subcutaneous heparin. There is some confusion about the role of aspirin and its duration of action.

Iris protein antibodies in serum of patients with juvenile rheumatoid arthritis and uveitis.

Homogenates of bovine iris were fractionated by gel filtration chromatography, and the column-eluted proteins were probed with pooled sera obtained from patients with pauciarticular juvenile rheumatoid arthritis (JRA). The serum pool prepared from patients with pauciarticular JRA and a history of anterior uveitis, but not from those without the eye disease, contained IgG antibodies which bound a low molecular weight iris antigen (LMW-IA) as measured by a modified ELISA. LMW-IA was protease-sensitive and contained at least four proteins of approximate molecular weights of 16, 13, 9 and 6.5 kD with no uronic acid or carbohydrate. Analysis of individual patient sera for IgG anti-LMW-IA antibody demonstrated that 1/20 (5%) pediatric non-rheumatic disease controls (NRDC), 1/19 (5.3%) non-uveitic pauciarticular JRA patients and 6/21 (28.6%) uveitic pauciarticular JRA patients were positive by ELISA. Levels of anti-LMW-IA antibody did not correlate with serum IgG concentration, the presence of IgG antibody to soluble retinal S antigen (S antigen) or reactivity to the low molecular weight fraction of bovine choroid (LMW-C). Ten of 21 (47.6%) children with pauciarticular JRA and uveitis had serum antibody that reacted with LMW-IA and/or retinal S antigen as compared to 1/20 (5%) NRDC patients and 3/19 (15.8%) patients with pauciarticular JRA uncomplicated by uveitis. Analysis of patient immunoreactivity to proteins of the anterior uveal tract may provide a greater understanding of pathogenic features related to arthritis-associated eye disease.

Anaesthesia for thoracoscopic pleurectomy and ligation of bullae.

A patient is described who, despite severe pre-operative respiratory disability, had her persistent pneumothorax successfully managed by thoracoscopic pleurectomy. The technique causes considerably less pain and interference with respiratory function postoperatively than does conventional thoracotomy. Potential anaesthetic problems arise because of the necessity of insufflating carbon dioxide at pressures of up to 1 kPa to maintain a pneumothorax during surgery.

Comparison of lumbar plexus block versus conventional opioid analgesia after total knee replacement.

A randomised controlled study was undertaken to assess the analgesic efficacy of continuous lumbar plexus block for the first 48 hours after total knee replacement surgery. Boluses of 0.5% bupivacaine with adrenaline 1 in 200,000 (0.3 ml/kg) were administered through a cannula inserted into the neurovascular sheath of the femoral nerve. Thirteen patients who received this block required significantly less morphine than a control group of 16 patients. Pain scores were similar and there were no complications related to this technique.

Polyphosphoinositide hydrolysis in response to light stimulation of rat and chick retina and retinal rod outer segments.

Phosphoinositides of chick and rat retina were labelled with [3H]inositol. Exposure of retinal preparations to light for 30 s caused loss of labelled phosphatidylinositol 4,5-bisphosphate and to a smaller extent of the other phosphoinositides. Similar light-induced changes were seen when rod outer segment preparations were used and, when these were illuminated in calcium-free media, phosphatidylinositol 4,5-bisphosphate was the only lipid affected. No inositol 1,4,5-trisphosphate was seen after either 30 s or 5 s of illumination of retina or 30 s illumination of rod outer segments. It is concluded that this compound plays no direct part in vertebrate photoreceptor light transduction, though phosphoinositide metabolism might relate to adaptation mechanisms.