Anaesthesia for reconstructive free flap surgery for head and neck cancer.

Head and neck cancer surgery presents significant challenges for the anaesthetist. A thorough multidisciplinary preoperative assessment and optimisation of the patient is essential, including nutritional and psychological evaluation. The incidence of a difficult airway is high, and the anaesthetist must be skilled in advanced airway techniques. Surgery is extensive, often requiring reconstructive surgery with either a pedicled or free flap. Detailed knowledge of flap physiology and anatomy is needed, and anaesthesia comprises careful management of mean arterial pressure, fluid administration, temperature control and oxygenation. The Enhanced Recovery after Surgery Society and the Society for Head and Neck Anaesthesia consensus recommendations provide guidance on current best practice. Despite continued debate, it now appears that this constitutes goal-directed fluid therapy, coupled with judicious vasopressor therapy sufficient to achieve an adequate mean arterial pressure. Emerging techniques such as prehabilitation and postoperative near-infrared spectroscopy flap monitoring provide hope of improved outcomes going forward.

Rates of reported codeine-related poisonings and codeine prescribing following new national guidance in Ireland.

PURPOSE: The aims of this study were to examine a national database to assess codeine poisonings before and after the new guidance for pharmacists while also evaluating rates of codeine prescriptions following the introduction of restrictions on supply. METHODS: Anonymised enquiry data of reported poisoning cases were reviewed for a period from 2005 to 2016 inclusive. The rate of pharmacy claims for codeine containing products was also examined using the national pharmacy claims database. Segmented regression analysis was used to detect changes in poisonings and claims before and after the new guidance. RESULTS: There were 1851 codeine-related poisonings reported over the study period. An annual decline was evident with a significant 33% reduction from 2010 to 2011 (ß2 coefficient for level change, 42.1; 95% CI, -68.1 to -16.0; P = 0.006). Following 2011, the declining rate of codeine poisonings plateaued. Analysis of the national pharmacy claims data revealed no change in the reimbursement rate for co-codamol products restricted by the guidance in 2010 (Incidence rate ratio 1.04, 95% CI, 0.997-1.08; P = 0.07). There was no corresponding increase in the reimbursement of alternative opioid medications. CONCLUSIONS: New guidance on codeine supply coincided with an initial reduction in reported codeine poisoning cases. This reduction was in keeping with the previous trend. However, this was without an increase in the prevailing rate of prescription claims for these products or potential substitutes. Policymakers may consider further restriction of codeine products to improve public health outcomes.

The epidemiology and type of medication errors reported to the National Poisons Information Centre of Ireland.

INTRODUCTION: Medication errors are widely reported for hospitalised patients, but limited data are available for medication errors that occur in community-based and clinical settings. Epidemiological data from poisons information centres enable characterisation of trends in medication errors occurring across the healthcare spectrum. AIM: The objective of this study was to characterise the epidemiology and type of medication errors reported to the National Poisons Information Centre (NPIC) of Ireland. METHODS: A 3-year prospective study on medication errors reported to the NPIC was conducted from 1 January 2007 to 31 December 2009 inclusive. Data on patient demographics, enquiry source, location, pharmaceutical agent(s), type of medication error, and treatment advice were collated from standardised call report forms. Medication errors were categorised as (i) prescribing error (i.e. physician error), (ii) dispensing error (i.e. pharmacy error), and (iii) administration error involving the wrong medication, the wrong dose, wrong route, or the wrong time. RESULTS: Medication errors were reported for 2348 individuals, representing 9.56% of total enquiries to the NPIC over 3 years. In total, 1220 children and adolescents under 18 years of age and 1128 adults (≥ 18 years old) experienced a medication error. The majority of enquiries were received from healthcare professionals, but members of the public accounted for 31.3% (n = 736) of enquiries. Most medication errors occurred in a domestic setting (n = 2135), but a small number occurred in healthcare facilities: nursing homes (n = 110, 4.68%), hospitals (n = 53, 2.26%), and general practitioner surgeries (n = 32, 1.36%). In children, medication errors with non-prescription pharmaceuticals predominated (n = 722) and anti-pyretics and non-opioid analgesics, anti-bacterials, and cough and cold preparations were the main pharmaceutical classes involved. Medication errors with prescription medication predominated for adults (n = 866) and the major medication classes included anti-pyretics and non-opioid analgesics, psychoanaleptics, and psychleptic agents. Approximately 97% (n = 2279) of medication errors were as a result of drug administration errors (comprising a double dose [n = 1040], wrong dose [n = 395], wrong medication [n = 597], wrong route [n = 133], and wrong time [n = 110]). Prescribing and dispensing errors accounted for 0.68% (n = 16) and 2.26% (n = 53) of errors, respectively. CONCLUSION: Empirical data from poisons information centres facilitate the characterisation of medication errors occurring in the community and across the healthcare spectrum. Poison centre data facilitate the detection of subtle trends in medication errors and can contribute to pharmacovigilance. Collaboration between pharmaceutical manufacturers, consumers, medical, and regulatory communities is needed to advance patient safety and reduce medication errors.

Mushroom poisoning in Ireland: the collaboration between the National Poisons Information Centre and expert mycologists.

BACKGROUND: Occasionally, mycologist assistance is requested to reliably identify mushroom species in symptomatic cases where there is a concern that a toxic species is involved. The aim of this study was to describe the epidemiology of mushroom poisoning in Ireland, to describe the working arrangement between the National Poisons Information Centre (NPIC) and professional mycologists and to present a case series detailing the circumstances when mycologists were consulted. METHODS: Computerised records from 1 January 2004 to 31 December 2009 were retrospectively reviewed and data on patient demographics, circumstances, and mushroom species collated. In 1999, the NPIC established a national registry of volunteer professional mycologists who are available 24 h/day for mushroom identification. The NPIC staff liaises directly with the mycologist and arranges transport of mushroom material. Digital photographic images are requested if there is likely to be a delay in arranging transportation of mushroom material, and the images are subsequently emailed to a mycologist. Five cases of suspected mushroom poisoning were chosen to demonstrate the inter-professional collaboration between the NPIC and mycologists. RESULTS: From 2004 to 2009, the NPIC was consulted about 70 cases of suspected mushroom exposures. Forty-five children ingested unknown mushrooms, 12 adults and 2 children ingested hallucinogenic mushrooms and 11 adults ingested wild toxic mushrooms that were incorrectly identified or confused with edible species. The mycologists were consulted 10 times since 1999. In this series, Amanita species were identified in two cases. In three cases, the species identified were Clitocybe nebularis, Coprinus comatus and Panaeolina foenisecii, respectively, and serious poisoning was excluded. Incorrect mushroom identification by a health care professional using the Internet occurred in two cases. The mycologists assisted Poisons Information Centres in Northern Ireland and the United Kingdom in two cases. Digital photographs facilitated tentative mushroom identification in two cases. CONCLUSION: Poison information centres should maintain a registry of expert mycologists who are available for consultation following potentially serious mushroom intoxications. Health care workers should not attempt to identify toxic mushroom species using the Internet as erroneous identification can occur. Digital photography may help with mushroom identification when there is likely to be a delay organising a physical examination of mushroom tissue.

Feasibility and efficacy of ultrasound-guided block of the saphenous nerve in the adductor canal.

BACKGROUND AND OBJECTIVES: Saphenous nerve (SN) block can be technically challenging because it is a small and exclusively sensory nerve. Traditional techniques using surface landmarks and nerve stimulation are limited by inconsistent success rates. This descriptive prospective study assesses the feasibility of performing an ultrasound-guided SN block in the distal thigh. METHODS: After the research ethics board's approval and written informed consent, 20 patients undergoing ankle or foot surgery underwent ultrasonography of the medial aspect of the thigh to identify the SN in the adductor canal, as it lies adjacent to the femoral artery (FA), deep to the sartorius muscle. An insulated needle was advanced in plane under real-time guidance toward the nerve. After attempting to elicit paresthesia with nerve stimulation, 2% lidocaine with 1:200,000 epinephrine (5 mL) and 0.5% bupivacaine (5 mL) were injected around the SN. RESULTS: The SN was identified in all patients, most frequently in an anteromedial position relative to the FA, at a depth of 2.7 +/- 0.6 cm and 12.7 +/- 2.2 cm proximal to the knee joint. Complete anesthesia in the SN distribution developed in all patients by 25 mins after injection. CONCLUSIONS: In this small descriptive study, ultrasound-guided SN block in the adductor canal was technically simple and reliable, providing consistent nerve identification and block success.

Minimum effective volume of local anesthetic for ultrasound-guided supraclavicular brachial plexus block.

BACKGROUND AND OBJECTIVES: The aim of this study was to determine the minimum effective anesthetic volume required to produce an effective supraclavicular block for surgical anesthesia using an ultrasound (US)-guided technique. METHODS: Twenty-one adults undergoing elective upper limb surgery received a US-guided supraclavicular block. The initial volume of local anesthetic (LA; 50:50 mixture of lidocaine 2% and bupivacaine 0.5% with epinephrine) injected was 30 mL, which was subsequently varied by 5 mL for each consecutive patient according to the response of the previous patient. The minimum effective anesthetic volume in 50% of patients was determined using the Dixon and Massey up-and-down method. The effective volume in 95% of patients (ED95) was calculated using probit transformation and logistic regression. RESULTS: The minimum effective anesthetic volume in 50% and calculated effective volume in 95% of patients were 23 mL (95% confidence interval, 13-39 mL) and 42 mL (95% confidence interval, 19-65 mL), respectively. Seven patients received supplemental LA, with no patient requiring a general anesthetic. CONCLUSION: In this study, the minimum volume required for US-guided supraclavicular block in 50% of patients was 23 mL, and in 95% of patients was 42 mL. Under the present study conditions, the calculated volume of LA required for US-guided supraclavicular block does not seem to differ from the conventionally recommended volume required for supraclavicular blocks using non-US-based nerve localization techniques.

Ultrasound-guided brachial plexus block in a patient with multiple glomangiomatosis.

BACKGROUND AND OBJECTIVES: Glomangiomas are rare, vascular tumors consisting of an afferent artery, arteriovenous canal, neuro-reticular elements, collagen, and efferent veins, and are most often located in the soft tissue of the upper extremities. We describe how the use of ultrasound-guided nerve blockade altered the anesthetic management of a patient with multiple glomangiomatosis undergoing elective forearm surgery. ULTRASOUND FINDINGS: A 32-year-old man was scheduled for excision of painful glomangiomas from the ulnar aspect of his right wrist, with exploration of his ulnar nerve. The anesthetic concerns included (1) morbid obesity, (2) chronic pain syndrome and opioid intolerance, (3) a potentially difficult airway, and (4) obstructive sleep apnea. Ultrasound-guided supraclavicular blockade was the proposed anesthetic of choice. Ultrasound scan of the supraclavicular fossa revealed numerous vascular lesions surrounding the divisions of the brachial plexus. Color Doppler imaging confirmed these pulsatile lesions to be vascular in origin. Even under two-dimensional ultrasound guidance, we believed that the risk of vascular puncture and unintentional intravascular injection of local anesthetic was high, and therefore we abandoned the supraclavicular approach. A successful ultrasound-guided axillary brachial plexus blockade was performed uneventfully. CONCLUSIONS: Although multiple glomangiomatosis is a rare disease, this case illustrates the invaluable contribution that ultrasound has made to modern, regional anesthetic practice, especially for patients with aberrant anatomy in whom traditional nerve-localization techniques could result in serious complications.

Should we add clonidine to local anesthetic for peripheral nerve blockade? A qualitative systematic review of the literature.

BACKGROUND AND OBJECTIVES: Although clonidine has been shown to prolong analgesia in central neuraxial blocks, its use in peripheral nerve blocks remains controversial. We performed a systematic review of the current literature to determine the benefit of adding clonidine to peripheral nerve blocks. METHODS: A systematic, qualitative review of double-blind randomized controlled trials on the benefit of clonidine as an adjunct to peripheral nerve block was performed. Studies were identified by searching PubMed (www.ncbi.nlm.nih.gov/entrez) and EMBASE (www.embase.com) databases (July 1991 to October 2006) for terms related to clonidine as an adjunct to peripheral nerve blocks. Studies were classified as supportive if the use of clonidine demonstrated reduced pain and total analgesic consumption, or prolonged block duration versus negative if no difference was found. RESULTS: Twenty-seven studies were identified that met the inclusion criteria. Five studies included a systemic control group. The total number of patients reviewed was 1,385. The dose of clonidine varied from 30 to 300 mug. Overall 15 studies supported the use of clonidine as an adjunct to peripheral nerve blocks with 12 studies failing to show a benefit. Based on qualitative analysis, clonidine appeared to prolong analgesia when added to intermediate-acting local anesthetics for axillary and peribulbar blocks. CONCLUSIONS: Clonidine improves duration of analgesia and anesthesia when used as an adjunct to intermediate-acting local anesthetics for some peripheral nerve blocks. Side-effects appear to be limited at doses up to 150 mug. Evidence is lacking for the use of clonidine as an adjunct to local anesthetics for continuous catheter techniques. Further research is required to examine the peripheral analgesic mechanism of clonidine.

Coagulopathy after cardiac surgery may be influenced by a functional plasminogen activator inhibitor polymorphism.

BACKGROUND: Cytokine-mediated inflammation and coagulopathy may occur after cardiac surgery. In this study we investigated the temporal pattern of plasminogen activator inhibitor-1 (PAI-1) gene expression after cardiac surgery and its relation with PAI genotype, and obtained preliminary data regarding its relation to perioperative morbidity. METHODS: The relative change in PAI-1 mRNA 1, 6, and 24 h after cardiopulmonary bypass (CPB) was measured from mononuclear cells in 82 patients undergoing elective cardiac surgery. DNA was analyzed for carriage of the 4G/5G PAI-1 polymorphism. RESULTS: PAI-1 gene expression decreased after CPB in all patients. A larger reduction in PAI-1 gene expression was observed in homozygous carriers of the 5G allele. Homozygous carriers of the 5G allele were also more likely to receive transfusion of coagulation blood products. There was no relation between change in PAI-1 gene expression and duration of CPB. CONCLUSIONS: PAI-1 gene expression decreased over time after CPB. We found a link between PAI-1 genotype, PAI gene expression, and transfusion of coagulation products after cardiac surgery.

The occurrence of severe sepsis and septic shock are related to distinct patterns of cytokine gene expression.

Patient response to acute bacterial infection is highly variable. Differing outcomes in this setting may be related to variations in the immune response to an infectious insult. Using quantitative real-time polymerase chain reaction, we quantified gene expression of the tumor necrosis factor alpha(TNFalpha), interferon gamma (IFNgamma), and interleukin 10 (IL10), IL12p35, and IL4 genes in 3 patient groups. These groups consisted of an intensive care unit (ICU) cohort who presented with severe sepsis or septic shock, a group of noncritically ill ward patients with documented Gram-negative bacteremia, and a group of healthy controls. Greater interleukin 10 messenger RNA (mRNA) levels were detected in the ICU group in comparison with both the bacteremic and control groups (P < 0.0001). More TNF-alpha mRNA was detected in the ICU group when compared with the control group (P < 0.0001). However, TNF-alpha mRNA was most abundant in the bacteremic group (P = 0.0007). Lesser IFN-gamma mRNA levels were detected in the ICU group when compared with both the bacteremic and control groups (P < 0.0003). Cytokine mRNA levels were not associated with the occurrence of shock upon admission to ICU. On the seventh day of ICU stay, the presence of shock was associated with lesser IFN-gamma mRNA (P = 0.0004) and lesser TNF-alpha mRNA (P = 0.001). Survivors had greater TNF-alpha mRNA copy numbers on day 7 of ICU stay than nonsurvivors (P = 0.002). We conclude that a proinflammatory response is the appropriate response in the setting of infection and is associated with lesser requirements for inotropes and lesser mortality. Quantitative real-time polymerase chain reaction can be used to predict infection outcome in clinically relevant situations where enzyme-linked immunosorbent assay testing has proved disappointing.

Gene polymorphism and requirement for vasopressor infusion after cardiac surgery.

BACKGROUND: Genes in the class III region of the MHC, encoding proteins involved in inflammation and vascular regulation, were investigated for association with the occurrence of vasodilation and requirement for vasopressor infusion. METHODS: A cohort of 236 elective cardiac surgical patients was studied. Hemodynamic and metabolic variables and dosage of vasopressor medications were recorded for the first 12 hours of intensive care unit admission after cardiac surgery on an electronic patient record. Demographic factors and operative details were recorded from other institutional databases. The DNA was extracted from peripheral blood mononuclear cells and genotyped for the presence of polymorphic alleles in genes coding for inflammation-related proteins. RESULTS: Carriage of the dimethylarginine dimethylaminohydrolase II (DDAH II) -449 G allele and the lymphotoxin alpha +252 G allele was significantly less frequent in patients who required infusions of vasopressors after cardiac surgery. On multivariate analysis, prior myocardial infarction, prolonged bypass, and the homozygous carriage of the DDAH II C allele were associated with postoperative vasopressor requirement. CONCLUSIONS: Vasopressor requirement after surgery may be related to an interaction of genotype, preoperative morbidity, and prolonged surgery.

Tumor necrosis factor-alpha and interleukin-10 gene expression in peripheral blood mononuclear cells after cardiac surgery.

OBJECTIVE: Cytokine response after cardiac surgery may be genetically influenced. A study was carried out to investigate the relation between cytokine gene expression in peripheral blood mononuclear cells, genotype, and clinical events after cardiac surgery. DESIGN: A case-control study was performed. SETTING: Cardiac intensive care unit in a university hospital. SUBJECTS: A total of 82 patients having elective cardiac surgery were divided into those having uncomplicated recovery (n = 48) or recovery complicated by hyperlactatemia or requirement for inotropic support (n = 34). INTERVENTIONS: The relative change in peripheral blood mononuclear cell tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) messenger RNA 1 and 6 hrs after cardiopulmonary bypass was compared with a baseline preoperative level using quantitative reverse transcriptase polymerase chain reaction. DNA was analyzed for carriage of TNF-alpha and IL-10 polymorphic alleles. MEASUREMENTS AND MAIN RESULTS: Cardiopulmonary bypass was longer in duration in the complicated group. TNF-alpha gene expression decreased and IL-10 gene expression increased in peripheral blood mononuclear cells after surgery when compared with preoperative levels. One hour after cardiopulmonary bypass, the complicated group had more TNF-alpha and less IL-10 messenger RNA production than the uncomplicated group. The IL-10/TNF-alpha ratio was greater in uncomplicated than in complicated recovery patients. An IL-10 haplotype was identified that was less frequent in the complicated group. There was no difference between groups in TNF-alpha genotype. On multivariate analysis, cardiopulmonary bypass time and the IL-10/TNF-alpha messenger RNA ratio were independent predictors of outcome. CONCLUSIONS: There is a predominant anti-inflammatory cytokine response after uneventful cardiac surgery. IL-10 may have a protective role after cardiac surgery.

Posterior lumbar plexus block: anatomy, approaches, and techniques.

Lumbar plexus is an effective but underused regional technique that was described nearly 3 decades ago. The original description has been modified several times based on advances in technology, localization, and imaging techniques. This review provides an overview of the history, anatomy, and techniques described to perform this block.