bluuebunny/crossref_metadata_2025 huggingface dataset:
Continuous microspinal anaesthesia: another perspective on mechanisms inducing cauda equina syndrome
Authors: Ilias W. K. , Klimscha W. , Skrbensky G. , Weinstabl R. , Widhalm A.
Published: March 2003

Continuous spinal anaesthesia through a microspinal catheter technique has been criticised on several grounds and is now rarely used. This paper reviews the possible causes of the cauda equina syndrome which have been described and, on the basis of research in cadaver preparations, a glass ‘spine’ model and clinical experience in over 200 cases, suggests how these problems might be avoided. The use of careful insertion techniques, limiting the length of catheter inserted into the subarachnoid space and the use of no stronger than 0.5% bupivacaine solution are recommended.
The peri‐operative management of atrial fibrillation
Authors: Nathanson M. H. , Gajraj N. M.
Published: March 2003

Atrial fibrillation is a common arrhythmia frequently seen in surgical patients. The onset of new atrial fibrillation during the peri‐operative period is less common. There are many possible precipitating factors, although volatile agents themselves may have an antifibrillatory action. The management of atrial fibrillation includes removal of any precipitating factors and treatment of the arrhythmia itself. Immediate management of acute‐onset atrial fibrillation is usually direct current cardioversion. Alternatively, anti‐arrhythmic drugs can be used to achieve cardioversion. In patients with rapid, chronic atrial fibrillation or those refractory to cardioversion, priority is given to control of the ventricular rate. Thrombo‐embolism is a significant risk if atrial fibrillation is paroxysmal or persists for more than 48 h.
Safe pre‐operative fasting times after milk or clear fluid in childrenA preliminary study using real‐time ultrasound
Authors: Sethi A. K. , Chatterji C. , Bhargava S. K. , Narang P. , Tyagi A.
Published: March 2003

Gastric emptying of orange‐flavoured glucose (group I), low‐fat milk (group II) and breast milk (group III) was evaluated in 45 ASA grade I children of ≤ 5 years of age by using real‐time ultrasonography and residual gastric volume and pH was then measured. In 15 more children, residual gastric volume and pH was measured after a midnight fast (group IV). Mean (SD) gastric emptying time in group I was 1.53 (0.25) h (range 1.00–1.75), group II 2.32 (0.31) h (range 1.75–2.75) and group III 2.43 (0.27) h (range 2.00–2.75). According to Robert and Shirley's criteria, no children of group I and II were found to be ‘at risk’ at 2 h and 3 h, respectively, but 13.3% of group III children were labelled as ‘at risk’ at 3 h. The incidence of ‘at risk’ children in group IV was 33.3%. It was concluded that 3% fat milk or 17.5% glucose in a volume of 10 ml.kg−1 (maximum volume of 100 ml) can be given in children safely 3 h and 2 h, respectively, before anaesthesia. More real‐time studies are required on breast milk to establish guidelines for its potential use as a pre‐operative feed 3 h before anaesthesia.
Cost‐effectiveness of ondansetron for postoperative nausea and vomiting
Authors: Tramèr M. R. , Phillips C. , Reynolds D. J. M. , McQuay H. J. , Moore R. A.
Published: March 2003

The decision as to whether prophylaxis against postoperative nausea and vomiting is better than treatment of established postoperative nausea and vomiting could be made on the basis of cost‐effectiveness. The cost‐effectiveness of ondansetron was calculated using data from published quantitative systematic reviews of randomised trials. Milligrams of ondansetron required to achieve a desired endpoint were chosen as a cost unit. Modelling was based on a cohort of 1000 patients, and examined control event rates (i.e. incidence of postoperative nausea and vomiting without prophylaxis) of between 10 and 90%. In a sensitivity analysis, cost‐effectiveness of recommended intravenous doses (4 mg for treatment and prophylaxis) was compared with minimal effective doses as shown by meta‐analysis (1 mg for treatment, 8 mg for prophylaxis). Fewer patients experience any postoperative nausea and vomiting symptoms with prophylaxis compared with treatment. But prophylaxis is only marginally more effective than treatment, and treatment of established postoperative nausea and vomiting with effective doses (i.e. 1 or 4 mg) is more cost‐effective and safer than prophylaxis with effective doses (i.e. 4 or 8 mg). Reasons for this are the selective treatment of patients who actually need treatment, the high success rate with the lowest dose tested (1 mg) in established postoperative nausea and vomiting, and the disappointing antinausea effect of prophylactic ondansetron even at an eight‐fold higher dose.
The effects of EMLA and a topical formulation of 4%amethocaine (Ametop) on pain associated with retrobulbar injection
Authors: Browne J. , Raza A. , Awad I. , Tan B. , McAdoo J. , Shorten G.
Published: March 2003

Retrobulbar block is commonly performed to provide anaesthesia for cataract extraction. This technique can cause significant discomfort. A prospective, randomised, placebo‐controlled trial was carried out to investigate the efficacy of a eutectic mixture of local anaesthetics (EMLA) and a 4% amethocaine topical formulation (Ametop) in reducing the pain of retrobulbar injection. Ametop and EMLA proved to be of similar efficacy, both being superior to a placebo in alleviating the discomfort of retrobulbar block. No significant side‐effects were observed with the use of either formulation.
Randomised double‐blind comparison of morphine vs. a morphine–alfentanil combination for patient‐controlled analgesia
Authors: Ngan Kee W. D. , Khaw K. S. , Wong E. L. Y.
Published: March 2003

In a randomised, double‐blind study, we compared a combination of morphine and alfentanil with morphine alone for patient‐controlled analgesia (PCA) after Caesarean section under spinal anaesthesia. After surgery, patients were randomly allocated to receive PCA with a bolus dose of either morphine 0.75 mg plus alfentanil 0.125 mg (Group MA, n = 40) or morphine 1.5 mg alone (Group M, n = 37) with a lockout interval of 8 min and no hourly dose limit. Clinical assessments were made in the first 24 h, after which patients completed a written questionnaire. There were no differences between groups in PCA usage or visual analogue scale pain scores measured at 2, 4, 6 and 24 h. There was a low incidence of side‐effects in both groups. In the questionnaire, patients in Group MA scored higher compared with Group M when asked to grade speed of onset and effectiveness of analgesia after a PCA bolus; there were no differences in grading for duration of analgesia or overall patient satisfaction. Addition of alfentanil to morphine may have advantages for PCA.
Antiseptic‐bonded central venous catheters and bacterial colonisation
Authors: Hannan  , Juste  , Umasanker  , Glendenning  , Nightingale  , Azadian  , Soni
Published: March 2003

This study was undertaken to evaluate the impact of chlorhexidine/silver sulphadiazine‐bonded catheters on the incidence of colonisation and catheter‐related sepsis in critically ill patients. Threehundred and fifty‐one catheters were inserted into 228 patients during the study period, 174chlorhexidine/silver sulphadiazine‐bonded catheters and 177 standard catheters. Indications for catheter removal were: death, clinical redundancy and clinical evidence of local or systemic infection. All catheter tips were sent to the microbiology laboratory for semiquantitative analysis of bacterial colony count. Seventy‐one (40.2%) of the standard catheters and 47 (27.2%) of the antiseptic‐bonded catheters were found to be colonised on removal (p < 0.01). Eight cases (4.7%) of catheter‐related sepsis were associated with standard catheters and three cases (1.7%) with antiseptic‐bonded catheters, however, this reduction was not statistically significant. Our results indicate that the use of antiseptic‐bonded catheters in critically ill patients significantly reduces the incidence of bacterial colonisation.
Ventilator‐associated pneumoniaDiagnosis, pathogenesis and prevention
Authors: Young P. J. , Ridley S. A.
Published: March 2003

Ventilator‐associated pneumonia is common, difficult to diagnose, affects the most vulnerable of patients and carries a high mortality. During prolonged mechanical ventilation the oropharynx, sinuses, dentition and stomach of critically ill patients become colonised with pathogenic bacteria. Colonised secretions pool in the oropharynx and subglottic space. These secretions repeatedly gain access to the lower airways by leakage past the tracheal tube cuff. If host defence mechanisms are overwhelmed, multiplication occurs in the lower respiratory tract producing an inflammatory response in the bronchioles and alveoli. The inflammatory response is characterised by capillary congestion, leucocyte and macrophage infiltration and fibrinous exudation into the alveolar spaces. If this inflammatory response occurs more than 48 h after intubation, it is called ventilator‐associated pneumonia. Prevention depends on reducing upper airway and gastrointestinal reservoirs of bacteria, reducing or abolishing aspiration of these bacteria past the tracheal tube cuff and enhancing bacterial clearance from the lower airways.
Clinical indicators and other complications in the recovery room or postanaesthetic care unit
Authors: Peskett M. J.
Published: March 2003

Clinical indicators and complications occurring in the recovery room or post anaesthetic care unit were recorded for patients who had an anaesthetic procedure during 1995, 1996 and 1997 (n = 13 266). Clinical indicators measured were those developed by the Australian Council on Healthcare Standards in conjunction with the Australian and New Zealand College of Anaesthetists, and three other indicators. All patients were assessed and positive data were collected by nursing staff on a standardised form which was checked and collated by the anaesthetist responsible for the recovery room (the author). The rates for some indicators were higher than the Australian Council on Healthcare Standards 1997 rates, but the overall rates of complications were comparable with, or lower than, those in published series. Clinical indicator data are seen as a valuable quantitative tool for quality assurance, particularly if collected as part of a more comprehensive programme.
Minimum alveolar sevoflurane concentrations required for insertion of the cuffed oropharyngeal airway and the laryngeal mask airway: a comparative study
Authors: Tanaka M. , Watanabe S. , Nishikawa T.
Published: March 2003

Both the cuffed oropharyngeal airway and the laryngeal mask airway share a similar property of being less stimulating to the upper airway than the tracheal tube. This study was conducted to compare sevoflurane concentrations required for insertion of the cuffed oropharyngeal airway and the laryngeal mask airway in elderly and young adult patients. Forty‐one elderly (65–90 years) and 34 young adult (18–50 years) patients, scheduled for elective surgery during spontaneous breathing anaesthesia were randomly assigned to either the cuffed oropharyngeal airway or the laryngeal mask airway group. After a predetermined end‐tidal concentration of sevoflurane had been established and maintained for at least 20 min, insertion of the device was attempted without neuromuscular relaxants or other adjuvants. Each concentration at which insertion of the device was attempted was predetermined by modification of Dixon's up‐and‐down method with 0.5% as the step size. Sevoflurane MACCOPA [mean 1.17 (SD 0.38)%, 0.77–1.56% (95% CI)] was significantly less than MACLMA [2.00 (0.52)%, 1.45–2.55%, p < 0.05] for elderly patients. Similarly, sevoflurane MACCOPA [1.33 (0.38)%, 0.94–1.73%] was significantly less than MACLMA [2.00 (0.42)%, 1.56–2.44%, p < 0.05] for young adult patients. There were no significant differences in either MACCOPA or MACLMA between the elderly and the young adult patients. We conclude that the insertion of the cuffed oropharyngeal airway can be accomplished at a lower sevoflurane concentration, and hence, is less stimulating to the upper airway than that of the laryngeal mask airway.
A comparison of ICU mortality prediction using the APACHE II scoring system and artificial neural networks
Authors: Wong L. S. S. , Young J. D.
Published: March 2003

The aim of this study was to compare the ability of artificial neural networks and the Acute Physiology and Chronic Health Evaluation II score to predict mortality in adult intensive care units. The same physiological variables were used in both predictive models to predict hospital mortality from a data set of 8796 patients collected from 26 adult intensive care units in the United Kingdom and Ireland as part of the Intensive Care Society study. The results from the two models were compared with the actual outcome. The overall prediction accuracy and the overall goodness‐of‐fit of all the models were assessed. Both predictive models showed similar goodness‐of‐fit and prediction discrimination. The overall predictive and classification performance of the artificial neural network developed matched and in some aspects was better than that of Acute Physiology and Chronic Health Evaluation II.
Bispectral index monitoring: comparison of two types of electrode
Authors: Thøgersen B. , Ørding H.
Published: March 2003

Bis‐monitoring is a new method of monitoring anaesthetic depth. Bis‐monitoring is easy to perform, but the Bis‐monitor and the original, disposable electrodes are expensive. The aim of this study was to determine whether the original Zipprep electrodes could be replaced by the much cheaper electrocardiogram electrodes. We compared bispectral index measurements, conducted using both types of electrode in the same patients before anaesthesia, and during light and deep anaesthesia, in patients randomly allocated to receive either sevoflurane or propofol anaesthesia. We found very good agreement between the measurements from the two different sets of electrodes. The impedance in the electrocardiogram electrodes was higher than in the Zipprep electrodes, but this did not affect the bispectral index. No other problems with either type of electrode were detected. It is concluded that Zipprep electrodes can be replaced by electrocardiogram electrodes in normal clinical practice.
The implications of HIV for the anaesthetist and the intensivist
Authors: Avidan M. S. , Jones N. , Pozniak A. L.
Published: March 2003

The acquired immune deficiency syndrome has reached pandemic proportions. Anaesthetists should be aware of the implications of dealing with increasing numbers of both diagnosed and undiagnosed, symptomatic and asymptomatic, human immunodeficiency virus‐infected patients in the fields of intensive therapy, operating theatre anaesthesia, obstetrics and pain management. With recent advances, important insights have been gained into the pathogenesis of human immunodeficiency virus. Molecular techniques allow quantification of viral burden, and together with CD4 T‐lymphocyte count, prognosis and response to therapy can be evaluated. New drugs and therapeutic regimens have improved prognosis for those who are infected with the virus and vertical transmission of infection from mother to infant can be minimised. Should accidental occupational exposure to the virus occur, a prophylactic regimen of antiretroviral drugs can be administered in an attempt to prevent subsequent human immunodeficiency virus infection.
Use of diclofenac in children with asthma
Authors: Short J. A. , Barr C. A. , Palmer C. D. , Goddard J. M. , Stack C. G. , Primhak R. A.
Published: March 2003

This study investigated the effect of diclofenac on the lung function of 70 children aged 6–15 years with a diagnosis of asthma, recruited from a hospital respiratory clinic. Peak flow and a forced expiratory flow‐volume loop were measured and the patients were then given 1–1.5 mg.kg−1 effervescent diclofenac orally. Spirometry was repeated at 10, 20 and 30 min, a 15% decrease in results being considered a significant reduction in lung function. No patient demonstrated a consistent reduction in lung function of  > 15% during the study and there were no reports of wheezing or increased bronchodilator use after completion of the spirometry. In conclusion, we studied a group of genuine asthmatics and found no clinically significant incidence of bronchospasm with the use of a single therapeutic dose of diclofenac.
Emergence characteristics and postoperative laryngopharyngeal morbidity with the laryngeal mask airway: a comparison of high versus low initial cuff volume
Authors: Brimacombe J. , Holyoake L. , Keller C. , Barry J. , Mecklem D. , Blinco A. , Weidmann K.
Published: March 2003

In this study we tested the hypothesis that the initial cuff volume of the laryngeal mask airway influences emergence characteristics and postoperative laryngopharyngeal morbidity. One hundred and sixty adult patients undergoing minor surgery were randomly assigned for airway management with the laryngeal mask airway with either a fully inflated cuff (LMA‐High) or a semi‐inflated cuff (LMA‐Low). Anaesthesia was with propofol, nitrous oxide, oxygen and isoflurane. Following insertion, the cuff was inflated with either 15 or 30 ml for the size 4 (females) and 20 or 40 ml for the size 5 (males). At the end of surgery, a blinded observer documented the presence or absence of adverse airway events (hypoxia, hypercapnea, coughing, retching, regurgitation/vomiting, airway obstruction, hypoventilation, hiccupping, biting, body movement or shivering) during every 1 min epoch and cardiorespiratory variables (heart rate, mean blood pressure, arterial oxygen saturation, end‐tidal carbon dioxide and respiratory rate) every 5 min until the patient was awake and the laryngeal mask airway removed. Patients were interviewed about pharyngolaryngeal morbidity (sore throat, dysphonia and dysphagia) immediately before leaving the postanaesthesia care unit and 18–24 h following surgery. Analysis by epoch showed more partial airway obstruction in the LMA‐High group, but analysis by patient numbers revealed no difference. Heart rate was slightly higher in the LMA‐High group upon arrival in the postanaesthesia care unit, but otherwise there were no differences in cardiorespiratory responses. Sore throat and dysphagia were more common in the LMA‐High group. We conclude that, in general, emergence characteristics with the laryngeal mask airway are not influenced by the volume of air used to inflate the cuff, but that postoperative sore throat and dysphagia are more likely at high initial cuff volumes.
A semiquantitative analysis of the dynamics of a Goldman‐type vaporiser
Authors: Young D. A. , Brosnan S. G. , White D. C.
Published: March 2003

When a turbulent flow of a carrier gas is passed over a liquid anaesthetic agent contained in a vaporiser of Goldman design, evaporation from the cooled surface leads rapidly to a succession of fluid instabilities which set in at characteristic critical conditions. An initially quiescent boundary layer at the surface is sequentially replaced by a thin layer of toroidal (Bénard–Marangoni) convection cells which are driven by surface tension gradients. These are then augmented by Rayleigh–Bénard convection driven by gravity, the whole process terminating in intermittent columnar plunging of cold fluid from a chaotic surface layer of pulsating thickness to the base of the liquid pool. Residual striations from these plunging columns persist throughout the bulk of the liquid so long as evaporation continues. The ultimate state is then one in which turbulence occurs throughout both liquid and vapour phases. In this paper, a semiquantitative analysis of the system dynamics is given with supportive experimental evidence where possible.
Anasthesia in myotubular (centronuclear) myopathy
Authors: Breslin D. , Reid J. , Hayes A. , Mirakhur R. K.
Published: March 2003

A patient with a known history of myotubular myopathy presented for surgery for insertion of a tibial nail. Anasthesia was induced and maintained using an intravenous anasthetic technique. Neuromuscular function was assessed using mechanomyography, which showed a profound reduction in muscle contractility. In view of this, the use of muscle relaxants was avoided altogether. Nerve conduction was normal but electromyography showed small motor units, with generalised distribution, suggesting mild to moderately severe myopathy. The patient made a slow but uneventful recovery.
A comparison of blind and lightwand‐guided tracheal intubation through the intubating laryngeal mask
Authors: Kihara S. , Watanabe S. , Taguchi N. , Suga A. , Brimacombe J. R.
Published: March 2003

We have tested the hypothesis that intubation success rates, haemodynamic changes, airway complications and postoperative pharyngolaryngeal morbidity differ between blind and lightwand‐guided intubation through the intubating laryngeal mask airway. One hundred and twenty paralysed anasthetised adult patients (ASA I–II, no known or predicted difficult airways) were assigned in a random manner to one of two equal‐sized groups. In the blind group, patients were intubated blindly through the intubating laryngeal mask airway. In the lightwand group, patients were intubated through the intubating laryngeal mask airway assisted by transillumination of the neck with a lightwand. A standard sequence of adjusting manoeuvres was followed if resistance occurred during intubation or if transillumination was incorrect. The number of adjusting manoeuvres, time to intubation, intubation success rates, haemodynamic changes (pre‐induction, pre‐intubation, postintubation), oesophageal intubation, mucosal trauma (blood detected), hypoxia (oxygen saturation < 95%) and postoperative pharyngolaryngeal morbidity (double‐blinded) were documented. Overall intubation success was similar (blind, 93%; lightwand, 100%), but time to successful intubation was significantly shorter (67 vs. 46 s, p = 0.027) and the number of adjusting manoeuvres was significantly fewer (p = 0.024) in the lightwand group. There were no significant differences in blood pressure or heart rate between the groups at any time. Oesophageal intubation occurred more frequently in the blind group (18 vs. 0%, p = 0.002). The incidence and severity of mucosal injury, sore throat and hoarseness were similar between the groups. We conclude that lightwand‐guided intubation through the intubating laryngeal mask is superior to the blind technique.
Pregnancy, anaesthesia and Guillain Barré syndrome
Authors: Brooks H. , Christian A. S. , May A. E.
Published: March 2003

Two case histories of pregnant women with Guillain Barré syndrome (acute demyelinating polyradiculoneuritis) are reported. The first required anaesthesia during the second trimester for a minor surgical procedure. The second woman was admitted to the Intensive Care Unit in the first trimester and was ventilated for 18 weeks. Both babies were carried to term and delivered by Caesarean section. A review of the management of Guillain Barré syndrome in pregnancy discusses anaesthetic management, intensive care and the use of plasmapheresis and γ‐globulins. The care of pregnant women recovered from Guillain Barré syndrome is also discussed.
Cricoid pressure: which hand?
Authors: Cook T. M. , Godfrey I. , Rockett M. , Vanner R. G.
Published: March 2003

We studied 20 anaesthetic assistants applying simulated cricoid pressure with the left or right hand in random order. Simulated cricoid pressure was continued for up to 5 min with one hand and then, after resting, with the other hand. Applied pressure was measured at intervals and the subjects were blind to the results. Nineteen assistants were right‐handed and all routinely applied cricoid pressure with their right hand. Mean (SD) force applied during simulated ‘awake’ cricoid pressure was 13.8 (5.7) N with either left or right hand, and during ‘anaesthetised’ cricoid pressure it was initially 25.1 (8.2) N and 24.7 (8.8) N with left or right hand, respectively. Mean force was maintained above 20 N and below 30 N throughout the study period with either hand. Force applied with the left hand was significantly lower than with the right hand but the difference was clinically insignificant (0.4 N). Inadequate or excessive force was more frequently associated with use of the left hand (p < 0.0001). Cricoid pressure was released before 5 min in three cases, two left‐handed and one right‐handed. Our results demonstrate that anaesthetic assistants apply a lower force than is classically taught and are able to maintain the force with either hand for a sustained period. Application with the left hand is justified where clinically indicated but may have a lower margin for error than when applied with the right hand.
Brainstem death and ventilator trigger settings
Authors: Willatts S. M. , Drummond G.
Published: March 2003

A patient with cerebral infarction was certified clinically brainstem dead. However, 4 h after the diagnosis of death, while the patient was being ventilated using the biphasic positive airway pressure mode, the ‘assist’ indicator light on the Drager Evita 2 ventilator illuminated intermittently. There was no evidence of spontaneous breathing. ‘Triggering’ was probably caused by a decrease in airway pressure in time with cardiac contraction. The trigger flow rate is crucial as factors other than the patient's inspiratory effort can initiate flow from the ventilator with very sensitive settings.
Cremasteric reflex test as an objective indicator of spinal anaesthesia*
Authors: Okuda Y. , Mishio M. , Kitajima T. , Asai T.
Published: March 2003

We studied 100 men who were scheduled for urological surgery (Group 1) and another 50 men for orthopaedic surgery (Group 2). We attempted to anaesthetise both sides of the lower body in Group 1 and to anaesthetise one leg in Group 2 by injecting 0.3% hyperbaric dibucaine intrathecally. The presence or absence of the cremasteric reflex and loss of sensation to pinprick higher than the first lumbar dermatome were examined by two researchers who were blind to each other’s results. In Group 1, both the reflex and the pinprick sensation were always absent bilaterally 5 min after intrathecal injection. In Group 2, in 23 of 50 patients the reflex had become absent bilaterally; in all these patients, bilateral sensory loss was detected. In the remaining 27 patients, both the reflex and the pinprick sensation were absent on the operation side, whereas both were present on the nonoperation side. Sensitivity, specificity and positive or negative predictive value for the cremasteric reflex were all 100%. Disappearance of the cremasteric reflex is a simple objective indicator of spinal anaesthesia at the first lumbar dermatome. This test may be useful in patients who cannot give reliable answers to conventional tests, such as the pinprick test.
Tracheal intubating conditions after induction with sevoflurane 8% in children
Authors: Blair J. M. , Hill D. A. , Bali I. M. , Fee J. P. H.
Published: March 2003

We studied tracheal intubating conditions in 120 healthy children, aged 3–12 years, in a blinded, randomised clinical trial. Children were randomly allocated to one of three groups: group PS, propofol 3 mg.kg−1 and succinylcholine 1 mg.kg−1 (n = 40); group PA, propofol 3 mg.kg−1 and alfentanil 10 µg.kg−1 (n = 40); group SF, sevoflurane 8% in 60% nitrous oxide in oxygen for 3 min (n = 40). Tracheal intubating conditions were graded according to ease of laryngoscopy, position of vocal cords, coughing, jaw relaxation and movement of limbs. Overall intubating conditions were acceptable in 39 of 40 children in the propofol/succinylcholine group, 21 of 40 children in the propofol/alfentanil group and 35 of 40 children in the sevoflurane group. Children receiving propofol and succinylcholine or sevoflurane had better intubating conditions overall than those given propofol and alfentanil (p < 0.01). In conclusion, anaesthetic induction and tracheal intubation using sevoflurane 8% for 3 min is a satisfactory alternative to propofol with succinylcholine in children.
A comparison of opiate‐ and epidural‐induced alterations in splanchnic blood flow using intra‐operative gastric tonometry
Authors: Mallinder P. A. , Hall J. E. , Bergin F. G. , Royle P. , Leaper D. J.
Published: March 2003

Several methods are available to measure splanchnic blood flow and gut ischaemia. Tonometry is most practical for peri‐operative use. Epidural blockade from T5 to T11 causes mesenteric arteriovenous vasodilation and may increase splanchnic blood flow. This study assesses the ability of tonometry to measure differential effects of opiate and epidural analgesia on splanchnic blood flow. Forty patients for elective colorectal surgery were randomly allocated to receive epidural infusion or intravenous morphine. Gastric mucosal Pco2, pHi, standard pHi, Pco2 gap and pH gap were measured after induction and on termination of surgery. These parameters were within normal limits at the end in most cases and there was no significant difference between the groups. The complication rate was similar in both groups and was not correlated with low pHi, but was correlated with blood loss. We were unable to demonstrate a difference in splanchnic perfusion, as assessed by gastric tonometry, between the two groups.
The pharmacokinetics of caudal ropivacaine 0.2% in children
Authors: Wulf H. , Peters C. , Behnke H.
Published: March 2003

This study evaluates the pharmacokinetics of ropivacaine in children after caudal epidural injection. Twenty male children undergoing inguinal hernia repair were enrolled after ethics committee approval and informed parental consent, and were grouped according to age (10 ‘infants’ aged less than 1 year and 10 ‘toddlers’ aged 1–5 years). After induction of general anaesthesia, caudal epidural injection using ropivacaine 0.2% 1 ml.kg−1 was performed. Plasma concentrations of ropivacaine in the first 2 h after injection were determined by reversed‐phase high‐pressure liquid chromatography. Caudal blockade with ropivacaine 2 mg.ml−1 resulted in mean (SD) peak plasma concentrations of 0.73 [0.27]µg.ml−1 in infants and 0.49 [0.21]µg.ml−1 in toddlers (p < 0.01). Maximum plasma concentrations occurred after a median [range] period of 60 [15–90] min and 52.5 [30–120] min in infants and toddlers, respectively. Two infants (weighing 3.8 and 5.0 kg) showed the highest individual maximum plasma concentrations: 1.31 and 1.11 µg.ml−1. No clinical signs of local anaesthetic toxicity were observed. The results of the present investigation suggest that, from a pharmacokinetic point of view, caudal blockade using ropivacaine 0.2% 1 ml.kg−1 can be regarded as a safe technique in children, i.e. in infants as well as in toddlers.
Epidural catheter fixation: subcutaneous tunnelling with a loop to prevent displacement
Authors: Tripathi M. , Pandey M.
Published: March 2003

A method of fixing the epidural catheter by subcutaneous tunnelling and looping was devised. A prospective, randomised, double‐blind, clinical trial was conducted in 68 adult patients, where postoperative pain relief was planned by thoracic epidural analgesia. In the tunnelled group (n = 34), the epidural catheter was fixed with a subcutaneous tunnel and loop, whereas in controls (n = 34), a simple loop of epidural catheter was left over the skin without tunnelling. An adhesive dressing was used to secure the epidural catheter. We observed that catheter dislodgement occurred in only one patient in the tunnelled group compared to seven control patients (21%). Despite local inflammation of the skin around the tunnel in nine patients (27%), no catheter infection (positive culture tip) was found in patients with subcutaneous tunnelling for the extended period of 4–5 days. The method described allows the catheter to lie flat on the skin and outward traction of the catheter during movement of patients is dampened by the interposed loop which protects it against dislodgement. At the time of removal, both ends of the catheter can be removed under direct vision. In conclusion, we recommend this fixation method in cases where epidural analgesia is to be used for postoperative pain relief.
Apoptosis: mechanisms and clinical implications
Authors: Kam P. C. A. , Ferch N. I.
Published: March 2003

The balance between cell survival and death is under tight genetic control. A multiplicity of extracellular signals and intracellular mediators is involved in maintaining this balance. When the cell is exposed to physical, biochemical or biological injury, or deprived of necessary substances, it activates a series of stress‐response genes. With minimal insults, the cell may recover. With greater insults, single cell death, or apoptosis, results; the cell dies and is recycled to its neighbours. If the insult overwhelms a large number of cells then necrosis ensues, with an accompanying inflammatory response. Dysregulation of the controlling mechanisms of this system results in disease. Deficient apoptosis is associated with cancer, auto‐immunity and viral infections. Excessive apoptosis is associated with ischaemic heart disease, stroke, neurodegenerative disease, sepsis and multiple organ dysfunction syndrome. There are myriad therapeutic options unfolding as understanding is gained of apoptosis and its control.
Effects of propofol on endothelial cells subjected to a peroxynitrite donor (SIN‐1)
Authors: Mathy‐Hartert M. , Mouithys‐Mickalad A. , Kohnen S. , Deby‐Dupont G. , Lamy M. , Hans P.
Published: March 2003

We investigated the effect of propofol on endothelial cells subjected to the peroxynitrite (ONOO−) donor 3‐morpholino sydnonimine (SIN‐1). Cells were incubated overnight with 0.5, 1.0 or 2.0 mm SIN‐1, with or without 10−3 m propofol (Diprivan®). Cytotoxicity, assessed by measuring the release of pre‐incorporated 51Cr, increased when the concentration of SIN‐1 increased, and was significantly decreased by 10−3 m propofol (90%, 78% and 28% of protection against 0.5, 1.0 and 2.0 mm SIN‐1, respectively). Cell protection against 1 mm SIN‐1 was tested with 0.03–1.0 mm propofol and this was compared to tyrosine, a target molecule for peroxynitrite. Propofol protected cells in a dose‐dependent manner (r = 0.98; p < 0.001) and was as effective as tyrosine. Finally, using high‐performance liquid chromatography, we demonstrated that propofol reacted with ONOO− more rapidly than did tyrosine, inhibiting nitrotyrosine formation. In the absence of propofol, 3.5 mm ONOO− with 1 mm tyrosine yielded 39.6% nitrotyrosine, but nitrotyrosine was not produced when 5 mm propofol was added. We conclude that propofol protects endothelial cells against the toxicity of ONOO−. The anti‐oxidant properties of propofol can be partially attributed to its scavenging effect on peroxynitrite, a property that might be relevant in pathological situations involving a significant contribution of peroxynitrite to tissue damage.
Peripheral nerve injuries associated with anaesthesia
Authors: Sawyer R. J. , Richmond M. N. , Hickey J. D. , Jarrratt J. A.
Published: March 2003

Peripheral nerve injuries can occur at any time during the peri‐operative period. The long‐term disability that results may have serious consequences for a patient. The incidence of peri‐operative nerve injuries can be reduced by anaesthetists being aware of their causes and pathophysiology. This review article aims to explain the incidence, pathophysiology and medicolegal implications of peri‐operative nerve injury and provides suggestions as to how they may best be avoided.
Pharmacokinetics of transdermal fentanyl in the peri‐operative period in young children
Authors: Paut O. , Camboulives J. , Viard L. , Lemoing J. P. , Levron J. C.
Published: March 2003

The pharmacokinetics of transdermal fentanyl were assessed in eight children aged 18–60 months, weighing 11–20 kg and monitored postoperatively in the intensive care unit. A patch, delivering 25 µg.h−1 of fentanyl, was applied for 72 h from the induction of anaesthesia. Plasma fentanyl concentrations were measured over 144 h. Mean (SD) peak concentration of fentanyl was 1.7 (0.66) ng.ml−1 and time to reach maximal plasma concentration was 18 (11) h. The elimination half‐life was 14.5 (6.2) h, and the area under the curve for plasma fentanyl concentration (0–144 h) was 86.8 (27) ng.h.ml−1. Maximal fentanyl concentration was negatively correlated with patient age (r = − 0.71; p = 0.049) but not with body weight. These results suggest that the pharmacokinetics of transdermal fentanyl in children are similar to those in adults.
Continuing medical education by anaesthetists in Scotland: activities, motivation and barriers
Authors: Chambers W. A. , Ferguson K. , Prescott G. J.
Published: March 2003

A postal questionnaire survey was carried out to determine the activities, motivation and barriers to continuing medical education amongst career grade anaesthetists in Scotland. Four hundred and ten consultants and 49 non‐consultant career grade anaesthetists were surveyed with a response rate of 84.5%. All respondents had taken part in some educational activities in the past two years. Over 80% had attended 10 or more departmental meetings and over 90% had attended meetings of a Regional society or National meetings. Less than 50% had attended for clinical experience with a colleague and only 20% had done so in another centre. There were trends of changing educational activity with increasing age. The most common motivation was to keep up to date for current clinical duties with keeping up to date for teaching second, but younger consultants were more likely to undertake continuing medical education activities in case their clinical duties changed. Perceived barriers to continuing medical education were similar for internal and external activities but funding was less of a limitation for those working in district general hospitals. There is scope for encouraging activities such as clinical experience with a colleague and a need to explore in greater detail the perception of barriers to continuing medical education and their influence on participation.
The anaesthetic logbook – a survey
Authors: Nixon M. C.
Published: March 2003

All anaesthetic trainees must maintain a logbook. The recent extension of Specialist Registrar training from 4 to 5 years, granted by the Specialist Training Authority, is conditional upon a change to competency‐based training. The Royal College of Anaesthetists defines competency as possession of the ‘trinity’ of knowledge, skills and attitudes. This raises the question of whether the present logbook is of value in recording training. I surveyed a national cohort of trainees to investigate the current logbook: how it is being used, its value and its shortcomings. All respondents kept logbooks, but 81% and 69% experienced problems recording subspecialty experience in Intensive Care and Pain, respectively. Less than 50% regularly analysed their logbooks and for 67% of Specialist Registrars, no (or minimal) attention was paid to the logbook at assessments. Overwhelmingly, 97% did not believe that the current logbook assessed competency. The value of Training Portfolios is discussed.
Spinal endoscopy in chronic low back pain with radiculopathy A prospective case series
Authors: Richardson J. , McGurgan P. , Cheema S. , Prasad R. , Gupta S.
Published: March 2003

All 38 patients listed for day‐case spinal endoscopy over a 12‐month period (April 1998 – April 1999), who had chronic severe low back pain with a radiculopathic element, were studied prospectively. The mean [range] pain duration before treatment was 10.9 [2–26] years and 50% had failed back surgery syndrome. In all patients in whom treatment was completed (n = 34), the pain‐generating nerve roots were located through symptom interaction with the patient. All had epidural scar tissue, 14 (41%) having dense adhesions. Mobilisation of adhesions around the nerve root (neuroplasty) was performed so that a pocket was formed for the subsequent placement of bupivacaine, Depomedrone and clonidine. No intra‐operative complications occurred and side‐effects were minimal. Follow‐up over a 12‐month period showed statistically significant reductions in pain scores and disability. Spinal endoscopy may be the diagnostic method of choice for epidural fibrosis. It has substantial therapeutic and research potential. Prospective randomised studies are required.
Identifying the more patent nostril before nasotracheal intubation
Authors: Smith J. E. , Reid A. P.
Published: March 2003

We have studied the reliability of two simple pre‐induction tests used to select the more patent nostril for nasotracheal intubation by comparing their results with those obtained from fibreoptic examination of the nostrils, in 75 maxillo‐facial patients requiring nasotracheal intubation under general anaesthesia, who had no history of nasal obstruction. The tests comprised (1) estimation of the rate of airflow through each nostril during expiration by palpating the passage of air when the contralateral nostril was occluded, and (2) asking for the patient's assessment of airflow through the nostrils, following the administration of a vasoconstrictor. After each test, noses were classified as left or right nostril clearer or nostrils equally clear. After the induction of general anaesthesia, bilateral nasendoscopies were performed and videotape recordings of these were later analysed by an otolaryngologist who had no knowledge of the test results. Intranasal abnormalities were identified and noses were again classified as left or right nostril clearer or nostrils equally clear. There was no significant difference between the overall diagnostic success rates of the two tests (44% and 47%, respectively). In patients with intranasal abnormalities, the numbers of correct diagnoses made by the two tests were not significantly different and were also not significantly different from the number of correct selections made if only the right nostril or only the left nostril had been used for the intubation. In view of the relatively high diagnostic failure rates, anaesthetists should not rely on the two tests investigated when selecting the best nostril for nasotracheal intubation.
Postoperative pain relief using thoracic epidural analgesia: outstanding success and disappointing failures
Authors: McLeod G. A. , Davies H. T. O. , Munnoch N. , Bannister J. , Macrae W.
Published: March 2003

Six hundred and forty patients received epidural analgesia for postoperative pain relief following major surgery in the 6‐year period 1993–1998. Although satisfactory pain relief was achieved in over two‐thirds of patients for a median duration of 44 h after surgery, one‐fifth of patients (133 individuals) still experienced poor pain relief. Almost one out of three patients (194 individuals) had a problem with their epidural. Eighty‐three patients (13%) suffered a technical failure and 84 (13%) patients had their epidurals removed at night time when pain‐free because of pressure on beds. Seven patients had their epidural replaced and subsequently experienced excellent pain relief for a median of 77 h. Lack of resources prevented a further 480 patients from receiving the potential benefits of epidural analgesia. These results would suggest that the practical problems of delivering an epidural service far outweigh any differences in drug regimens or modes of delivery of epidural solutions.
Clinical evaluation of the Mapleson theoretical ideal fresh gas flow sequence at the start of low‐flow anaesthesia with isoflurane, sevoflurane and desflurane*
Authors: Ip‐Yam P. C. , Goh M. H. , Chan Y. H. , Kong C. F.
Published: March 2003

Mapleson used a computer spreadsheet model to predict the theoretical ideal fresh gas flow sequence at the start of low‐flow anaesthesia. The aim was to increase the end‐expired partial pressure of inhalational agent (PE′an) to one minimum alveolar concentration (MAC) as quickly as practicable and then to keep it constant. Ninety adult patients undergoing elective tonsillectomy under general anaesthesia were randomly allocated to one of three groups (n = 30) to receive isoflurane, sevoflurane or desflurane in oxygen. Fresh gas flow and vaporiser settings as specified by Mapleson were followed in all cases except that the maximum setting for desflurane was 18% (2.7 MAC instead of 3 MAC). Recordings of PE′an were made at 1, 2, 3, 4, 5, 7, 10, 15 and 20 min. Mean values of PE′an exceeded 1 MAC by 2 min in all three groups and remained above this value throughout. Each group's PE′an measurements were divided by their respective 1‐MAC value. A simple two‐level model (with patients at level 2 and time at level 1), with measurements at 1 min excluded, showed that the fitted value at 2 min and the time‐weighted mean for 2–20 min for PE′iso (1.042 [95% CI 0.980–1.104] and 1.044 [0.984–1.104], respectively) were not significantly different from its 1‐MAC value, whereas those of the PE′sevo (1.169 [1.119–1.219] and 1.143 [1.119–1.219]) and PE′des (1.305 [1.261–1.349] and 1.140 [1.098–1.182]) were significantly higher than their respective 1‐MAC values. The Mapleson concept of an initial high fresh gas flow and high vaporiser settings, followed first by reduced high fresh gas flow, as followed in this clinical study, results in PE′an values close to or slightly higher than predicted in the spreadsheet model.
A pilot study of patient‐led identification of the midline of the lumbar spine
Authors: Wills J. S. , Bowie R. , Bogod D. G.
Published: March 2003

Summary The midline of the lumbar spine is usually identified by palpation of the spinous processes. Placement of an epidural or spinal needle is more difficult when these bony landmarks are impalpable. This pilot study investigated the ability of 50 healthy volunteers to identify the midline of their own backs, using light touch or proprioception. The midline as identified in this manner was compared with the ‘gold standard’ as defined by the interspinous line. Sensation to light touch was the most accurate, with 90% of the volunteers able to identify the midline to within 6.5 mm. Proprioception using a finger to touch the midline was less accurate. This study was carried out on volunteers with palpable spinous processes but suggests that, in certain circumstances, a patient‐led identification of the midline may be of value.
A survey of the use of portable ultrasound for central vein cannulation on critical care units in the UK
Authors: Jefferson P. , Ogbue M. N. , Hamilton K. E. StC. , Ball D. R.
Published: March 2003

A questionnaire was sent to 288 critical care units in the UK to assess the use of portable ultrasound machines to assist central vein cannulation. There was a 58% response rate. Ultrasound guidance was used by 36 (21.6%) units for central vein cannulation. Of these, only four (11.1%) used it routinely and 25 (69.4%) used it when faced with a difficult vein cannulation. Half of the units with ultrasound facilities may be using it suboptimally. Of those units not using ultrasound for central vein cannulation, 70 (53%) said it was because of lack of equipment and 51 (38.9%) did not think that it was necessary. Overall, over half of the units did not audit complications of central vein cannulation.
An unusual cause of stridor after thyroidectomy
Authors: Ahmed S. , Clarke D. , Vaughan R. S. , Wheeler M. H.
Published: March 2003

Summary Twelve days after subtotal thyroidectomy, an air pocket developed in a patient's neck. The pressure in this pocket had gradually increased as small amounts of air, probably associated with coughing, came out of a tiny hole in the trachea to form a pneumocoele. This produced limited surgical emphysema, causing venous congestion and oedema of the soft tissues of the larynx, which in turn led to increasing airway obstruction. We believe that this is the first reported case of a pneumocoele that gradually increased in size, causing airway obstruction that was almost certainly due to secondary laryngeal oedema.