- 22nd annual meeting of Chinese Society of Anesthesiology: New Century Convention Centre, Chengdu, China, September 11-14, 2014
- Nutrition in Intensive Care Medicine: Beyond Physiology
- Controversies in the Anesthetic Management of the Obese Surgical Patient
- Patient Care and Professionalism
- Handbook of Anesthesia
- Complications in Regional Anesthesia and Pain Medicine
- Unexpected benefit of videolaryngoscopy
Is number sense impaired in chronic pain patients?
Recent advances in imaging have improved our understanding of the role of the brain in painful conditions. Discoveries of morphological changes have been made in patients with chronic pain, with little known about the functional consequences when they occur in areas associated with ‘number-sense’; thus, it can be hypothesized that chronic pain impairs this sense.
First, an audit of the use of numbers in gold-standard pain assessment tools in patients with acute and chronic pain was undertaken. Secondly, experiments were conducted with patients with acute and chronic pain and healthy controls. Participants marked positions of numbers on lines (number marking), before naming numbers on pre-marked lines (number naming). Finally, subjects bisected lines flanked with ‘2’ and ‘9’. Deviations from expected responses were determined for each experiment.
Four hundred and ninety-four patients were audited; numeric scores in the ‘moderate’ and ‘severe’ pain categories were significantly higher in chronic compared with acute pain patients. In experiments (n=150), more than one-third of chronic pain patients compared with 1/10th of controls showed greater deviations from the expected in number marking and naming indicating impaired number sense. Line bisection experiments suggest prefrontal and parietal cortical dysfunction as cause of this impairment.
Audit data suggest patients with chronic pain interpret numbers differently from acute pain sufferers. Support is gained by experiments indicating impaired number sense in one-third of chronic pain patients. These results cast doubts on the appropriateness of the use of visual analogue and numeric rating scales in chronic pain in clinics and research.
- Local anaesthetic use in cancer surgery and disease recurrence: role of voltage-gated sodium channels?
Acute kidney injury after infrarenal abdominal aortic aneurysm surgery: a comparison of AKIN and RIFLE criteria for risk prediction
Although both Acute Kidney Injury Network (AKIN) and risk, injury, failure, loss, and end-stage (RIFLE) kidney disease criteria are frequently used to diagnose acute kidney injury (AKI), they have rarely been compared in the diagnosis of AKI in patients undergoing surgery for infrarenal abdominal aortic aneurysm (AAA). This study investigated the incidence of, and risk factors for, AKI, defined by AKIN and RIFLE criteria, and compared their ability to predict mortality after infrarenal AAA surgery.
This study examined 444 patients who underwent infrarenal AAA surgery between January 1999 and December 2011. Risk factors for AKI were assessed by multivariable analyses, and the impact of AKI on overall mortality was assessed by a Cox's proportional hazard model with inverse probability of treatment weighting (IPTW). Net reclassification improvement (NRI) was used to assess the performance of AKIN and RIFLE criteria in predicting overall mortality.
AKI based on AKIN and RIFLE criteria occurred in 82 (18.5%) and 55 (12.4%) patients, respectively. The independent risk factors for AKI were intraoperative red blood cell (RBC) transfusion and chronic kidney disease (CKD) by AKIN criteria, and age, intraoperative RBC transfusion, preoperative atrial fibrillation, and CKD by RIFLE criteria. After IPTW adjustment, AKI was related to 30 day mortality and overall mortality. NRI was 15.2% greater (P=0.04) for AKIN than for RIFLE criteria in assessing the risk of overall mortality.
Although AKI defined by either AKIN or RIFLE criteria was associated with overall mortality, AKIN criteria showed better prediction of mortality in patients undergoing infrarenal AAA surgery.
- Multicentre evaluation of perioperative red blood cells transfusions in China
- Chronic kidney disease: a gateway for perioperative medicine
- Error modelling in anaesthesia: slices of Swiss cheese or shavings of Parmesan
Arterial pressure above the upper cerebral autoregulation limit during cardiopulmonary bypass is associated with postoperative delirium
Mean arterial pressure (MAP) below the lower limit of cerebral autoregulation during cardiopulmonary bypass (CPB) is associated with complications after cardiac surgery. However, simply raising empiric MAP targets during CPB might result in MAP above the upper limit of autoregulation (ULA), causing cerebral hyperperfusion in some patients and predisposing them to cerebral dysfunction after surgery. We hypothesized that MAP above an ULA during CPB is associated with postoperative delirium.
Autoregulation during CPB was monitored continuously in 491 patients with the cerebral oximetry index (COx) in this prospective observational study. COx represents Pearson's correlation coefficient between low-frequency changes in regional cerebral oxygen saturation (measured with near-infrared spectroscopy) and MAP. Delirium was defined throughout the postoperative hospitalization based on clinical detection with prospectively defined methods.
Delirium was observed in 45 (9.2%) patients. Mechanical ventilation for >48 h [odds ratio (OR), 3.94; 95% confidence interval (CI), 1.72–9.03], preoperative antidepressant use (OR, 3.0; 95% CI, 1.29–6.96), prior stroke (OR, 2.79; 95% CI, 1.12–6.96), congestive heart failure (OR, 2.68; 95% CI, 1.28–5.62), the product of the magnitude and duration of MAP above an ULA (mm Hg h; OR, 1.09; 95% CI, 1.03–1.15), and age (per year of age; OR, 1.01; 95% CI, 1.01–1.07) were independently associated with postoperative delirium.
Excursions of MAP above the upper limit of cerebral autoregulation during CPB are associated with risk for delirium. Optimizing MAP during CPB to remain within the cerebral autoregulation range might reduce risk of delirium.
Clinical trial registration
clinicaltrials.gov NCT00769691 and NCT00981474.
- Perioperative management of diabetic patients: new controversies