Ventricular fibrillation in an ex‐premature neonate following reperfusion of ischemic gut incarcerated within an inguinal hernia

We describe the case of a neonate who underwent surgery for bowel obstruction. The child was born at 25 weeks postconception, and at the time of surgery, he had a postconceptual age of 44 weeks. He had undergone two previous laparotomy procedures for necrotizing enterocolitis. At laparotomy, there was unexpected extensive compromise to gut perfusion. The child developed ventricular fibrillation following the reperfusion of a segment of ischemic gut found incarcerated in an inguinal hernial orifice. We discuss the pathophysiology of intestinal ischemia–reperfusion (I‐R) injury. We have reviewed the interventions that may be employed to minimize the systemic impact of I‐R.     

N-acetylcysteine to reduce renal failure after cardiac surgery: a systematic review and meta-analysis

Purpose: To assess the effect of N-acetylcysteine (NAC) on acute renal failure and important clinical outcomes after cardiac surgery. Methods: Two reviewers performed literature searches, using EMBASE and PubMed, of randomized controlled trials investigating the renoprotective effect of N-acetylcysteine in cardiac surgery. Treatment effects were calculated as relative risks (RR) with 95% confidence intervals (CI). Heterogeneity and publication bias were assessed using the I² test and funnel plots, respectively. Meta regression was performed to assess the effect of baseline renal function and the use of aprotinin on renal function. Results: Seven randomized controlled trials (RCTs) (n=1000) were identified. No study could demonstrate, either independently or meta-analytically, an improvement in the postoperative increase in creatinine, mortality (RR 0.93, 95% CI 0.4 to 2.07), renal failure requiring renal replacement therapy (RR 1.01, 95% CI 0.49 to 2.12), myocardial infarction (RR 0.88, 95% CI 0.36 to 1.88), atrial fibrillation (RR 0.88, 95% CI 0.70 to 1. 10), or stroke (RR 0.69, 95% CI 0.27 to 1.69). There was a small, though significant increase in postoperative blood loss among patients treated with NAC (weighted mean difference I 19 mL 95% CI 51, 187). After meta regression neither increase in postoperative creatinine (r²=0.33) nor renal replacement therapy (r²=0.04) was associated with the baseline creatinine or with NAC dose (r²=0.04). Conclusion: This analysis did not find that treatment with NAC was associated with clinical renal protection during cardiac surgery, or improvement in other clinical outcomes.     

Spectral Entropy as a Monitor of Depth of Propofol Induced Sedation

Objective The aim of this prospective, observational study was to evaluate State and Response entropy (Entropy^TM Monitor, GE Healthcare, Finland), indices as measures of moderate (“conscious”) sedation in healthy adult patients receiving a low dose propofol infusion. Sedation was evaluated using: (I) the responsiveness component of the OAA/S scale␣(Observer’s Assessment of Alertness/Sedation scale) and (II) multi-channel electroencephalogram (EEG) interpretation by a clinical expert. Methods 12 ASA I patients were recruited. A target-controlled infusion of propofol was administered (using Schnider’s pharmacokinetic model) with␣an initial effect site concentration set to 0.5 μg ml⁻¹. A␣4 minute equilibrium period was allowed. This concentration was increased at 4 minute intervals by 0.5 μg ml⁻¹ to a maximum of 2.0 μg ml⁻¹. State (SE) and Response (RE), entropy values were recorded for each 4 minute epoch together with clinical sedation scores (OAA/S) and continuous multi-channel EEG. The multi-channel EEG recorded during the final minute of each 4 minute epoch or “patient/time unit” was presented to a neurophysiologist who assigned a label “sedated/not sedated”. SE/RE values were compared in patient/time units with clinical or EEG evidence of sedation versus those without. Results Mean SE and RE values were less in patient/time units when clinical evidence of sedation was present, [mean = 86.8 (95% CI, 84.0–88.3) and 94.3 (95%CI, 92–96.1)], P = 0.002 and P = 0.001, respectively. In patient/time units assigned the label “sedated” by the clinical neurophysiologist assessing the multi-channel EEG, SE and RE values were less [mean = 87.5 (95% CI, 86.3–88.4) and 95.0 (95% CI, 93.8–96.1)] P = 0.001 and P < 0.001, respectively. Conclusions A statistically significant decrease in SE and RE values was demonstrated in patient/time units in which clinical or EEG evidence of sedation was present. We conclude that spectral entropy offers potential as a monitor of propofol induced sedation Mahon P, Kowalski RG, Fitzgerald AP, Lynch EM, Boylan GB, McNamara B, Shorten GD. Spectral entropy as a monitor of depth of propofol induced sedation. Ethical Approval The Clinical Research Ethics Committee of the Cork Teaching Hospitals, Cork, Ireland approved the study protocol on 1st March 2005. The Clinical Research Ethics Committee of the Cork Teaching Hospitals, is a recognised Ethics Committee under regulation 7 of the European Communities (Clinical Trials on Medicinal Products for Human Use) regulations 2004, and is authorised to carry out the ethical review of clinical trials of investigational medicinal products. Presentation This work was presented in part (poster format) at the European Society of Anaesthesia, Annual Congress, Munich, Germany, June 9–12 2007. (Monitoring: equipment and computers poster section).Abstract reference: 3AP9-9. European Journal of Anaesthesia 2007(24) Suppl. 39 p 37.     

The Prognostic Significance of Nodal Ratio on Breast Cancer Recurrence and its Potential for Incorporation in a New Prognostic Index

Axillary nodal status is an inherent part of prognostic tools such as the Nottingham Prognostic Index (NPI). Literature suggests that nodal ratio is a stronger predictive parameter than the total number of positive nodes sampled. Studies also note improved survival in node‐negative patients with a larger proportion of nodes excised. The aim of this study was to assess disease‐free survival (DFS) comparing the number of negative and positive nodes excised and nodal ratio as the predictive parameters. Consecutive axillary lymph node dissections (ALND) were analyzed over a 25‐year period. Data were analyzed using Cox Regression and Kaplan–Meier survival curves. Eight hundred and forty‐nine ALNDs were identified, with 327 positive ALNDs and 268 node negative ALNDs incorporated in the study following exclusions. A prognostic index based on nodal ratio was devised and applied retrospectively to 327 positive ALNDs prior to 2002. This index was then prospectively validated in 116 consecutive positive ALNDs from 2002 to 2005. In node negative ALNDs, no significant difference in DFS was noted in patients having </≥10 nodes, or having </≥14 nodes removed. In node‐positive patients, nodal ratio was a stronger predictor of DFS than total positive nodes excised. A prognostic index incorporating nodal ratio more accurately predicts survival than the NPI in node‐positive patients as assessed in both a retrospective and a prospective patient cohort. Prognostic indices incorporating nodal ratio may prove more accurate than the current NPI. The extent of ALND did not impact survival in node‐negative patients.     

The Effect of Remote Ischemic Conditioning and Glyceryl Trinitrate on Perioperative Myocardial Injury in Cardiac Bypass Surgery Patients: Rationale and Design of the ERIC‐GTN Study

Remote ischemic conditioning (RIC) using transient limb ischemia/reperfusion has been reported to reduce perioperative myocardial injury in patients undergoing coronary artery bypass grafting and/or valve surgery. The role of intravenous glyceryl trinitrate (GTN) therapy administered during cardiac surgery as a cardioprotective agent and whether it interferes with RIC cardioprotection is not clear and is investigated in the ERIC‐GTN trial ( http://www.clinicaltrials.gov : NCT01864252). The ERIC‐GTN trial is a single‐site, double‐blind, randomized, placebo‐controlled study. Consenting adult patients (age > 18 years) undergoing elective coronary artery bypass grafting ± valve surgery with blood cardioplegia will be eligible for inclusion. Two hundred sixty patients will be randomized to 1 of 4 treatment groups following anesthetic induction: (1) RIC alone, a RIC protocol comprising three 5‐minute cycles of simultaneous upper‐arm and thigh cuff inflation/deflation followed by an intravenous (IV) placebo infusion; (2) GTN alone, a simulated sham RIC protocol followed by an IV GTN infusion; (3) RIC + GTN, a RIC protocol followed by an IV GTN infusion; and (4) neither RIC nor GTN, a sham RIC protocol followed by IV placebo infusion. The primary endpoint will be perioperative myocardial injury as quantified by the 72‐hour area‐under‐the‐curve serum high‐sensitivity troponin T. The ERIC‐GTN trial will determine whether intraoperative GTN therapy is cardioprotective during cardiac surgery and whether it affects RIC cardioprotection.     

A national survey of the anesthetic management of tonsillectomy surgery in children

Background: Tonsillectomy in children is a common procedure; however, there appears to be a significant degree of variability in anesthetic management. Thus far, there has been no large national survey looking at the perioperative care of these children. Objectives: We conducted a national survey with the aim of determining what represents common practice in the perioperative management of children undergoing tonsillectomy surgery. We compared the respondents’ management against evidence‐based practice. Methods: The survey took the form of a questionnaire, which was sent to members of The Association of Paediatric Anaesthetists (APAGBI) and to Royal College tutors. The questionnaire was sent in paper format to the College Tutors and in digital format to APAGBI members. Emphasis was placed upon preoperative preparation, induction technique, airway management, analgesia, postoperative nausea and vomiting strategy, fluid management and emergence from anesthesia. Results: Responses were obtained from 173 individuals representing a broad cross‐section of anesthetists from teaching and district general hospitals. Findings are as follows: the application of topical anesthetic cream is commonplace (93%), with Ametop^® being the primary preparation used; the intravenous route was preferred to induce anesthesia; most practitioners intubate the trachea to maintain the airway during anesthesia (79%); a muscle relaxant was employed to assist intubation of the trachea in 47% of respondents and the routine use of suxamethonium was reported to be uncommon (9%); the administration of prophylactic ondansetron and dexamethasone was reported by 79% and 70% of respondents respectively; and nonsteroidal anti‐inflammatory drugs (NSAIDs) are used by 77% of individuals either pre‐emptively or during the intraoperative period. Conclusions: Whilst there is individual variability in the management of these cases, the majority of anesthetists prefer the intravenous route for induction of anesthesia, after application of topical anesthetic cream. It is routine practice to intubate the trachea, administer paracetamol, NSAIDs, strong opiates and antiemetics.     

Use of methylene blue in pheochromocytoma resection: case report

We report the use of intravenous Methylene blue to treat the hypotension occurring following adrenal vein ligation in a case of pheochromocytoma resection in a child. The potential benefits and problems, including correct dosage, are discussed.