bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential errors in pulse oximetry
Authors: WEBB R. K. , RALSTON A. C. , RUNCIMAN W. B.
Published: February 2007

The published studies of pulse oximeter performance under conditions of normal, high and low saturation, exercise, poor signal quality and cardiac arrhythmia are reviewed. Most pulse oximeters have an absolute mean error of less than 2% at normal saturation and perfusion; two‐thirds have a standard deviation (SD) of less than 2%, and the remainder an SD of less than 3%. Some pulse oximeters tend to read 100% with fractional saturations of 97–98%. Pulse oximeters may be suitable hyperoxic alarms for neonates if the alarm limit chosen is directly validated for each device. Pulse oximeters are poorly calibrated at low saturations and are generally less accurate and less precise than at normal saturations; nearly 30% of 244 values reviewed were in error by more than 5% at saturations of less than 80%. Ear, nose and forehead probes respond more rapidly to rapid desaturation than finger probes, but are generally less accurate and less precise. Ear oximetry may be inaccurate during exercise. Low signal quality can result in failure to present a saturation reading, but data given with low signal quality warning messages are generally no less accurate than those without. Cardiac arrhythmias do not decrease accuracy of pulse oximeters so long as saturation readings are steady.
Caesarean section in undiagnosed Eisenmenger's syndrome
Authors: GILMAN D. H.
Published: February 2007

An obstetric patient is described in whom the first sign of cardiac disease was unexplained hypoxaemia during emergency anaesthesia for antepartum haemorrhage, with an eventual fatal outcome. The case highlights the importance of patient information at the booking clinic, and the implications of a raised haemoglobin in early pregnancy.
Chickenpox pneumonia, its complications and management
Authors: CLARK G. P. M. , DOBSON P. M. , THICKETT A. , TURNER N. M.
Published: February 2007

We report three cases of chickenpox pneumonia in adults, all of whom required intermittent positive pressure ventilation. One patient developed a variety of complications, and another, a pregnant woman, required extracorporeal membrane oxygenation.
Pulse oximetry compared with Doppler ultrasound for assessment of collateral blood flow to the hand
Authors: PILLOW K. , HERRICK I. A.
Published: February 2007

Ischaemic injury to the hand after arterial cannulation is a rare but well documented complication and routine testing of the adequacy of collateral circulation is widely advocated. The widespread availability of the pulse oximeter in the operating theatre, its applicability in circumstances where the patient is unable to cooperate, and its dependence on pulsatile blood flow suggest that this device could potentially be usefully applied to the assessment of collateral blood flow. The reliability of the pulse oximeter to detect the presence or absence of collateral circulation was prospectively compared to Doppler ultrasound in 109 hands from 64 adult patients. Nine hands demonstrated inadequate ulnar collateral flow, one hand demonstrated inadequate radial collateral flow and a persistent median artery was found in one hand. In all patients the results of pulse oximeter testing (probe placed on the thumb) correlated precisely with the results obtained with the Doppler device (probe located over the lateral aspect of the superficial palmar arch). These results demonstrate pulse oximetry to be a reliable method of assessing collateral blood flow to the hand before arterial cannulation.
Single operator cardiopulmonary resuscitation in ambulances
Authors: GREENSLADE G. L.
Published: February 2007

Cardiopulmonary resuscitation en route to hospital is performed by a single‐handed operator in many British ambulances. In this study, three emergency ventilation devices, and mouth‐to‐mouth breathing, were compared for effectiveness in unintubated patients. Seventeen paramedics used each method on a Laerdal manikin in a randomised order, under identical conditions. Three experienced cardiopulmonary resuscitation instructors repeated the tests in a moving ambulance. There were significant differences in minute volume (p < 0.01) and number of effective chest compressions (p < 0.05); mouth‐to‐mouth breathing produced the best overall results and the simplest device was a close second. The value of automatic ventilators for single‐operator cardiopulmonary resuscitation in unintubated patients is questioned.
Wound infiltration of local anaesthetic after lower segment Caesarean section
Authors: Trotter T. N. , Hayes‐Gregson P. , Robinson S. , Cole L. , Coley S. , Fell D.
Published: February 2007

The analgesic efficacy of subcutaneous wound infiltration with 20 ml of 0.5% bupivacaine after elective lower segment section Caesarean section was studied in 28 patients in a double‐blind randomised controlled manner using a patient‐controlled analgesia system. The mean 24‐hour morphine consumption of the placebo group and the bupivacaine group was similar (76 mg and 68 mg respectively). Analysis of the cumulative hourly morphine consumption failed to show any statistically significant differences between the groups. However, on a weight‐adjusted basis statistically significant differences in morphine consumption were demonstrated, although these may not be clinically important. Subjective experiences of pain, nausea and drowsiness assessed by linear analogue scoring were similar in both groups.
Comparison of the effects of oral nizatidine and ranitidine on gastric volume and pH in patients undergoing gynaecological laparoscopy
Authors: POPAT M. T. , DYAR O. J. , BLOGG C. E.
Published: February 2007

Ninety patients who presented for elective gynaecological laparoscopy as day cases were allocated at random to three groups and studied on a double blind basis to compare the effects of nizatidine, ranitidine or placebo on gastric secretion. All the patients received the active drugs or placebo orally at least 45 minutes before the induction of anaesthesia. After tracheal intubation gastric fluid was aspirated via an orogastric tube and the volume and pH of the aspirate were measured. Venous blood samples were obtained at the times of gastric sampling to determine the plasma levels of the drugs. The proportion of patients with both pH > 2.5 and volume < 25 ml were 100%, 90%, and 92.9% in the nizatidine, ranitidine and placebo groups respectively. There was no difference in volume between groups. Two patients in the nizatidine group without a measurable aspirate had blood levels less than the therapeutic range. The median pH values in both treated groups were significantly greater than in the placebo group, but there were no differences between the two treated groups. There were 19 (67.8%) patients in the placebo group with pH < 2.5. This was significantly higher than the 2 (7.4%) and 6 (20%) in the nizatidine and ranitidine groups respectively. When the time interval between drug administration and induction of anaesthesia was divided arbitrarily into 45‐90 minutes and > 90 minutes, all the patients in the nizatidine and ranitidine groups with pH < 2.5 were given the drugs in the 45–90 minute interval; this suggests a latent period is required before the gastric pH increases. Nizatidine may be an effective protective agent against acid aspiration syndrome.
Timing of surgery in congenital diaphragmatic hernia
Authors: CHARLTON A. J. , BRUCE J. , DAVENPORT M.
Published: February 2007

Eighty‐six consecutive patients with congenital diaphragmatic hernia presenting within 6 hours of birth to a regional neonatal surgical unit were reviewed. Patients were managed under a policy of delayed surgery which has evolved during the 6‐year study period. Overall survival (to leave hospital) was 70.9%. There were only seven postoperative deaths (10.3% of operations). Analysis of the 25 deaths in the light of postmortem findings and published exclusion criteria indicates that the availability of extracorporeal membrane oxygenation would have made little difference to overall survival.
A comparison of different pre‐oxygenation techniques in the elderly
Authors: McCARTHY G. , ELLIOTT P. , MIRAKHUR R. K. , McLOUGHLIN C.
Published: February 2007

The efficacy of five different techniques of pre‐oxygenation before a modified rapid intubation sequence was assessed, using oxygen saturation measurement, in patients aged over 65 years. Twenty patients in each group were pre‐oxygenated using four deep breaths or normal tidal breathing for 1, 2, 3, or 4 minutes. The acceptable period of apnoea was defined as the time taken to desaturate to 93%. The mean times (SD) taken to reach this end‐point were 3.7 (1.6), 4.1 (1.2), 5.4 (1.7), 5.4 (1.4) and 5.2 (1.7) minutes respectively. The apnoea times with 2, 3 and 4 minutes pre‐oxygenation were not significantly different from each other but were significantly longer than after four deep breaths and 1 minute. It is concluded that a pre‐oxygenation period of at least 2 minutes should be employed in the elderly before a rapid sequence induction.
Rectus sheath and mesosalpinx block for laparoscopic sterilization
Authors: FFARCS B.E. Smith , MacPherson G.H. , de Jonge M. , Griffiths J.M.
Published: February 2007

Thirty patients scheduled to undergo laparoscopic sterilisation were allocated at random to receive either a standardised general anaesthetic and rectus sheath block (group A), or standardised general anaesthetic combined with both rectus sheath and mesosalpinx blocks (group B). Group B patients had significantly less postoperative pain, as assessed by linear analogue scores (p < 0.025), and analgesic requirement (p < 0.05). By the 8th postoperative hour all 15 group B patients had been discharged from hospital, whilst only seven of 15 patients in group A were considered suitable for discharge at this time, (p < 0.05).
Morphine compared with diamorphine
Authors: ROBINSON S. L. , ROWBOTHAM D. J. , SMITH G.
Published: February 2007

The dose requirements and side effects of morphine were compared with those of diamorphine administered by patient‐controlled analgesia in 40 patients following elective total hip replacement. Patients were allocated randomly to receive in a double‐blind manner either morphine or diamorphine for postoperative pain relief. There were no significant differences between the two groups with regard to postoperative sedation, nausea, well‐being, pain relief and requirements for antiemetic drugs. The dose requirement for diamorphine was approximately 50% of that for morphine.
Intra‐operative patient‐controlled sedation
Authors: OSBORNE G. A. , RUDKIN G. E. , CURTIS N. J. , VICKERS D. , CRAKER A. J.
Published: February 2007

The quality of sedation and postoperative recovery have been assessed for intra‐operative sedation provided by either patient‐controlled sedation with propofol or a standard method using divided doses of midazolam and fentanyl, in 40 ASA 1 day surgery patients undergoing extraction of third molar teeth under local analgesia. Patient‐controlled sedation with propofol produced sedation no deeper than full eyelid closure with prompt response to verbal command, but deeper levels were seen in three patients in the midazolam and fentanyl group. Patient satisfaction was higher in the patient‐controlled sedation propofol group for both subjective intra‐operative feelings (p < 0.01) and willingness to have the procedure again in the same manner (p < 0.05). Amnesia was more limited to intra‐operative events (rather than extending into the postoperative period) in the patient‐controlled sedation propofol group (p < 0.05). Drug dose was correlated with duration of procedure and surgical difficulty in the patient‐controlled sedation propofol group but not in the midazolam and fentanyl group. Postoperative testing included a new computerised test, the FAST index, which indicated a dose‐dependent reduction in cognitive function in the midazolam and fentanyl group, which persisted until the time of discharge. Changes in cognitive function in the patient‐controlled sedation propofol group in the same postoperative interval were significantly less and not related to propofol dose.
Clinical evaluation of a spinal catheter technique in femoro‐popliteal graft surgery
Authors: Morrison L. M. M. , McClure J. H. , Wildsmith J. A. W.
Published: February 2007

The use of a 24‐gauge catheter for continuous spinal anaesthesia was evaluated in 20 patients undergoing femoro‐popliteal graft surgery for occlusive disease. The catheter was inserted through either a Tuohy or Quincke‐tip needle and isobaric amethocaine used for the initial injection. In five patients identification of the subarachnoid space was not straightforward, but clear difficulty with catheter insertion was encountered in only one. The range of blocks seen was wider than expected, but it was adequate for surgery 15 minutes after injection in 16 of the 20 patients. In another three the injection of a small dose of hyperbaric bupivacaine produced the necessary extension of block. Two patients (10%) required a general anaesthetic, one because of grossly inadequate spread of solution, the other because the catheter kinked and prevented injection of a second dose after the start of surgery.
Assessing intravenous cannulation and tracheal intubation training
Authors: Wilson M. E.
Published: February 2007

A simple graphical method is described that allows the assessment of a student's progress while learning intravenous cannulation and tracheal intubation. Thirty‐four students were studied during their initial training; 91% of those students who obtained a sufficient number of trials to allow a final assessment to be made met the criterion of 80% success for cannulation and 95% achieved similar success in intubation. Thirty‐one ambulance staff who returned for a 3‐day refresher course were also assessed; 44% (for intravenous cannulation) and 61% (for tracheal intubation) met the 80% success criterion.
Nausea and vomiting with use of a patient‐controlled analgesia system
Authors: Robinson S. L. , Fell D.
Published: February 2007

The incidence of nausea and vomiting following patient controlled analgesia and intramuscular morphine injections on demand was compared in a double‐blind randomised study of 32 healthy patients undergoing elective cholecystectomy. There were no significant differences between the two groups in mean 24 hour postoperative morphine consumption, subjective experience of pain, nausea and sedation assessed by visual linear analogue scoring, and the postoperative requirements for antiemetic therapy.
Incidence and management of airway problems in the CHARGE Association
Authors: Stack C.G. , Wyse R.K.H.
Published: February 2007

The airway problems associated with anaesthesia in patients with the CHARGE Association have been underreported. We undertook a retrospective review of 50 cases, of which anaesthetic records were available for 37 patients. Apart from choanal atresia and cleft lip and palate, 56% of patients had some other upper airway abnormality. There appeared to be greater difficulty in tracheal intubation with increase in age in four patients. The incidence and management of airway abnormalities are discussed.
Comparison of the combined effects of atropine and neostigmine with atropine and edrophonium on the lower oesophageal sphincter
Authors: HEIJKE S. A. M. , SMITH G. , KEY A.
Published: February 2007

In two groups (n = 11) of healthy patients, we have measured gastric, lower oesophageal and barrier pressures before and after antagonism of neuromuscular block during anaesthesia with nitrous oxide and isoflurane. In one group, atropine 1.2 mg and neostigmine 2.5 mg were given and in the second group atropine 0.6 mg with edrophonium 1 mg/kg. One minute after administration of the reversal agents, there was a significantly greater reduction in barrier pressures in the neostigmine and atropine group than in the edrophonium and atropine group, but subsequently, there was no significant difference between the two groups. We conclude that there is no clinical difference between the two reversal mixtures in terms of the risk of regurgitation in the immediate period after reversal.
Plasma catecholamine response to cataract surgery: a comparison between general and local anaesthesia
Authors: BARKER J. P. , VAFIDIS G. C. , ROBINSON P. N. , HALL G. M.
Published: February 2007

We studied the plasma catecholamine, plasma glucose and cardiovascular responses to cataract surgery in 20 elderly patients allocated randomly to receive either general anaesthesia or local anaesthesia by retrobulbar block. Local anaesthesia prevented the increase in plasma noradrenaline, adrenaline and glucose concentrations found in those patients who received general anaesthesia and also improved cardiovascular stability. The results show the beneficial effects of local anaesthesia in preventing the hormonal, metabolic and cardiovascular changes found when cataract surgery is conducted under general anaesthesia.
Oral ketamine
Authors: PETROS A. J.
Published: February 2007

Four cases of severely mentally handicapped young adults requiring day care dental treatment are reported. All had required varying degrees of restraint during previous dental treatments, which had been distressing for the patient, the relatives and the ward staff. In all cases, administration of oral ketamine 10 mg/kg, 30–60 minutes before the procedure, facilitated subsequent induction of anaesthesia.
Inaccuracy of pulse oximetry in patients with severe tricuspid regurgitation
Authors: STEWART K. G. , ROWBOTTOM S. J.
Published: February 2007

The accuracy of pulse oximetry was studied in a group of patients with severe tricuspid regurgitation. Measurements of arterial oxygen saturation from a finger and an ear probe were compared with those from a radial arterial blood sample analysed in vitro. Lower values were obtained using the pulse oximeter; the difference ranged from +2% to —11%. The discrepancies between pulse oximeter and laboratory oximeter readings were greater in this group of patients than in a control group who did not have tricuspid regurgitation. There was, however, no correlation between the magnitude of this discrepancy and either the peak central venous pressure or the venous pulse pressure.
Harold King
Authors: GRAY T. C.
Published: February 2007

Harold King was an analytical chemist of distinction, who worked with Sir Henry Dale and his colleagues in the Medical Research Institute, later the Medical Research Council. He helped to quash the theory that the anaesthetic action of ether was attributable to its impurities. Interest in alkaloids led to the elucidation of the structure of hyoscine, the synthesis of muscarine and the first isolation of crystalline tubocurarine for which he proposed a structural formula, work which influenced Bovet in the synthesis of gallamine. He proposed the synthesis of the homologous series of methonium compounds which included relaxant and hypotensive drugs. His collaboration with Rosenheim was outstanding and opened the way for synthesis of cholesterol and the steroids. He was always encouraging clinicians, and gave a sample of tubocurarine to Ranyard West who was the first to inject d‐tubocurarine into a human patient.
The first 24 hours after surgery
Authors: GAMIL M. , FANNING A.
Published: February 2007

The first 24 hours of the postoperative course of 2153 consecutive patients who had operations at the Nottingham Hospitals were studied in detail. Five per cent of patients had serious complications during this period; 15% of those having major operations, 1.8% having intermediate operations and 1.4% having minor operations. Thus, a significant number of patients were in an unstable condition for many hours after they were discharged from the main theatre recovery areas to the surgical wards. In 17 out of 23 patients who died and six out of six patients who suffered severe disability as a result of their surgery, the final outcome was a direct result of a sequence of events which began with an initial deterioration within 24 hours of surgery. We considered that, for at least 10 of these 29 patients, the outcome might have been different had more sophisticated postoperative facilities been available. In the light of this study we have identified the operations for which high dependency facilities are most likely to be required.
Intra‐arterial blood sampling for clotting studies
Authors: LEW J. K. L. , HUTCHINSON R. , LIN E. S.
Published: February 2007

Prothrombin time and activated partial thromboplastin time were measured in two groups of 30 patients each. Blood sampled from an arterial line after various discard volumes and from a central venous line were compared with direct venipuncture control samples. The arterial line flushing solution contained 1 unit of heparin per ml in group 1 and 2 units per ml in group 2. Our results confirmed that clotting studies carried out on blood samples from an arterial line or central venous line correlate well with those obtained from a venipuncture sample. The only exception was activated partial thromboplastin time in group 2 patients when the discard volume from the arterial line is only 2.5 ml above the deadspace volume of the connecting line. At least 5 ml of discard volume must be withdrawn before sampling, to obtain reliable results.
An assessment of the Cerebrotrac 2500 for continuous monitoring of cerebral function in the intensive care unit
Authors: SHEARER E. S. , O'SULLIVAN E. P. , HUNTER J. M.
Published: February 2007

Experience of the use of the Cerebrotrac 2500 EEG monitor in 17 patients subjected to artificial ventilation in an intensive care unit is reported; seven were receiving continuous sedation with morphine, midazolam and propofol singly or in combination and 10 received both sedation and the neuromuscular blocking agent, atracurium. The processed EEG patterns could not be precisely correlated with a standard clinical scoring system but were useful in determining the adequacy of sedation, particularly when a muscle relaxant was used. The monitor also shows considerable promise in the management of the paralysed patient with widespread convulsive activity in whom ischaemic brain damage may be occurring from epileptiform activity in the absence of any clinical manifestation. The ability to detect cerebral irritability or isolated epileptiform discharges using this apparatus is, however, questionable. The equipment was easy to use and robust; the running costs were 9.5p per hour.
The Extensometer
Authors: BRIMACOMBE J. R. , MACFIE A. G. , McCRIRRICK A.
Published: February 2007

The Extensometer is a new device capable of continuous accurate measurement of length over convex surfaces with a rapid response rate. This makes it a powerful research tool and a useful clinical instrument, particularly in the field of respiratory monitoring. This paper describes the principles behind the device. The linearity of its response was demonstrated in laboratory tests and its ability to quantify abdominal and chest wall movement was assessed in anaesthetised patients. Potential applications in the field of ventilatory pattern analysis and respiratory monitoring in anaesthesia and intensive care are discussed.
The Alton Dean pressure infusor: an evaluation
Authors: LALOR J. M. , ORTIZ J. C. G. , HOLDCROFT A.
Published: February 2007

An automatically pressurised infusor system, the Alton Dean infusor, has been compared with two types (cloth and plastic) of commonly used pneumatically pressurised bags. All the infusors had reasonably accurate pressure gauges but pressure could only be consistently maintained with the cloth infusors or with the Alton Dean infusors when connected to a compressed air supply. Sequential fast infusions were possible with all infusors, but simultaneous infusions could be limited in number when the pressure infusor was connected directly to pipeline gas. One of the Alton Dean pressure infusors tested had a leak in the pressurisation system, and the pressure adjustment valves were difficult to manipulate. These may require modification.
The role of the teaching hospital
Authors: Mulholland D. , Weir P. S.
Published: February 2007

All trainee anaesthetists on the Northern Ireland training scheme were surveyed about the techniques they use when anaesthetising elective paediatric cases. We compared the practice of doctors with specialist paediatric training to that of others and discovered that trainees with specialist training were more likely (p < 0.05) to admit parents during induction, but were less likely (p < 0.05) to visit their patients pre‐operatively and routinely to use suxamethonium. Other general findings were confusion over the re‐use of halothane and extensive involvement of trainee anaesthetists in neonatal resuscitation.
Dose‐response relationship and time course of action of Org 9426
Authors: LAMBALK L. M. , DE WIT A. P. M. , WIERDA J. M. K. H. , HENNIS P. J. , AGOSTON S.
Published: February 2007

The dose‐response relationship of Org 9426, its time course of action and the reversibility of the residual block by neostigmine have been investigated in 100 patients undergoing various anaesthetic techniques. The dose‐response was measured immediately following induction of anaesthesia. Doses of Org 9426, required for 50% and 90% depression of the twitch height, were 202 and 328 μg.kg−1, respectively. The clinical duration of the maintenance doses, 150 μg.kg−1, ranged from 9.5 to 13.4 min and from 12.8 to 18.9 min for the first and fifth maintenance doses, respectively. Spontaneous recovery indices (25%‐75%) were between 9.5 and 16.7 min; neostigmine methylsulphate administered at 25% recovery of the twitch height promptly reversed the residual block. No side effects were observed. The extent of the influence of the anaesthetic on the time course of Org 9426 appears to be fractional considering the variation of the time course within the separate groups.
Pain following thoracotomy
Authors: COE A. , SARGINSON R. , SMITH M. W. , DONNELLY R. J. , RUSSELL G. N.
Published: February 2007

Fifty‐eight patients scheduled for elective thoracotomy were randomly allocated to receive fentanyl by either the thoracic or the lumbar epidural route for postoperative analgesia. The infusion rate was adjusted to optimise analgesia. Dose adjustment, pain assessment and the incidence of side effects were monitored by a blinded observer at set times over the 24 hour study period. Similar pain scores were obtained in both groups at all assessment times. In addition, there was no significant difference in dose requirements or incidence of side effects between the two groups. There appears little justification for the use of the generally less familiar, and potentially more dangerous, thoracic approach when fentanyl alone is infused into the epidural space following thoracotomy.
Sensitivity to curare in patients with upper and lower motor neurone dysfunction
Authors: Fiacchino F. , Gemma M. , Bricchi M. , Giombini S. , Regi B.
Published: February 2007

Sensitivity to the action of nondepolarising relaxants was compared in muscles of upper and lower limbs in four syringomyelic patients undergoing elective neurosurgical procedures. It was observed that muscles with signs of lower motor neurone dysfunction are supersensitive to the action of nondepolarising relaxants. Terminal sprouting of motor axons and the occurrence of newly formed neuromuscular junctions may be responsible for a low synaptic efficacy and may explain the high sensitivity to factors that reduce the safety margin of neuromuscular transmission.
Predicting difficult intubation
Authors: FRERK C. M.
Published: February 2007

Two pre‐operative tests for the prediction of difficult intubation are assessed. A modified Mallampati test and a measurement of thyromental distance were performed at the pre‐operative visit of 244 patients whose tracheas were subsequently intubated under general anaesthesia. Patients in whom the posterior pharyngeal wall could not be visualised below the soft palate, who also had a distance of less than 7 cm between the prominence of the thyroid cartilage and the bony point of the chin proved significantly more likely to present difficulty with intubation. The performance of these two simple tests on all patients before operation should allow the majority of cases of difficult intubation to be anticipated.
Guided isoflurane injection in a totally closed circuit
Authors: El‐Attar A. M.
Published: February 2007

Twenty‐six patients undergoing middle ear surgery were anaesthetised using a completely closed circuit into which liquid isoflurane was injected using a syringe pump. The injection rate was guided by a table of calculated rates of isoflurane uptake, utilising the square root of time principle, at succeeding time intervals in different weight groups. A constant alveolar concentration of 1.3 MAC was aimed for. The injection rate was changed to that for the higher or lower weight group appropriate to the time interval whenever clinical signs indicated inappropriate depth of anaesthesia. A mean of10.3 ml liquid isoflurane was used to maintain anaesthesia for a mean of 82.3 minutes. Blood pressure was maintained at 75% of the pre‐operative value. Mean arterial blood gas data and changes in plasma catecholamine levels were within the normal range. The mean recovery time was 10.5 minutes. Syringe pump delivery of liquid isoflurane avoided fluctuations that result from bolus injections of unit dose. The implemented injection rate table, working as a therapeutic window, guided redosing, reduced calculation time and served as a record. The technique is safe, economic and adaptable to variations in uptake and response to inhalational anaesthetics.
Oral fluids prior to day surgery
Authors: Goodwin A. P. L. , Rowe W. L. , Ogg T. W. , Samaan A.
Published: February 2007

One hundred day surgical patients undergoing first trimester termination of pregnancy were randomly allocated to receive either 150 ml of clear fluid 1.5–2 hours before anaesthesia or to remain fasted from midnight the night before. Patients were anaesthetised using a total intravenous technique which consisted of propofol and alfentanil. No adverse intra‐operative events were noted in either group. There were no significant differences in immediate recovery time, or pain, nausea and headache scores at 30 or 120 minutes following recovery. The fasted group had less pain (p < 0.05) at 60 minutes after recovery than the fluid group, although the mean pain scores in both groups were low. Eighty two per cent of the patients returned questionnaires about pain, nausea and headache scores on arriving home, and at 12 and 24 hours after surgery. There were no significant differences between the two groups. In conclusion, pain, nausea and headache scores are low following total intravenous anaesthesia with propofol and alfentanil for termination of pregnancy and these were unaffected by the administration of 150 ml of clear fluid given approximately 1.5 hours pre‐operatively.
Addition of fentanyl to prilocaine for intravenous regional anaesthesia
Authors: ARMSTRONG P. , POWER I. , WILDSMITH J. A. W.
Published: February 2007

Fifteen volunteers underwent intravenous regional anaesthesia on two occasions using 40 ml 0.5% prilocaine, to which had been added either 2 ml 0.9% saline or 0.1 mg fentanyl (resultant concentration 2.5 μg/ml). There was no difference in the rate of onset of blockade of cold sensation from an ethyl chloride spray, or to sharp and touch pinprick sensation in either group. There was an increase in the incidence of nausea after tourniquet release in the fentanyl group. It is concluded that the addition of fentanyl 2.5 μg/ml to prilocaine 0.5% confers no benefit in intravenous regional anaesthesia.
Vasovagal asystole during spinal anaesthesia
Authors: McCONACHIE I.
Published: February 2007

A patient in whom vasovagal asystole was induced by the performance of a spinal anaesthetic in the upright position is described. This illustrates the importance of routine monitoring of the electrocardiograph during regional anaesthesia. The risk of vasovagal syncope may be increased by the use of the sitting position and by the omission of anxiolytic premedication.
Massive acute arsenic poisoning
Authors: JOLLIFFE D. M. , BUDD A. J. , GWILT D. J.
Published: February 2007

A 28‐year‐old male ingested 75 g of arsenic trioxide in a successful suicide attempt. The presentation, management and postmortem findings are presented and discussed.
Intubation guide marks for correct tube placement A clinical study
Authors: Mehta S. , Mehta S.
Published: February 2007

The tracheas of 140 adult patients were intubated with either TFX or Portex tracheal tubes. Guide marks were printed at variable distances proximal to the tube cuffs, and during intubation the guide mark was positioned at the level of the vocal cords. The distance between the bevel end of the tube and the carina was determined with a fibreoptic bronchoscope. The mean distance between the tip of the tracheal tube and the carina varied between 3.7 and 4.1 cm with the head in the neutral position. The tip of the tracheal tube approaches the carina by a mean distance of 0.5 cm when the head is moved from the extended position to the neutral position. It is recommended that a guide mark be placed 2.5 cm from the proximal end of the cuff in tubes used for adult males and 2.25 cm in tubes used for adult females. The use of guide marks is a simple, safe and reliable method for correct tracheal tube placement.
Patient‐controlled on‐demand epidural fentanyl
Authors: WELCHEW E. A. , BREEN D. P.
Published: February 2007

A prospective, open, clinical trial is described in which 20 patients having upper abdominal surgery were randomly allocated to receive fentanyl for postoperative analgesia by patient‐controlled demand analgesic computer by either the epidural or intravenous route. Hourly pain, sedation and nausea scores were very similar in the two groups during the first 24 hours after surgery. What few differences there were favoured the epidural group. There was a highly significant difference in fentanyl consumption between the two groups, with the intravenous group demanding consistently more than twice as much as the epidural group.
Serum bupivacaine concentrations following wound infiltration in children undergoing inguinal herniotomy
Authors: Mobley K.A. , Wandless J.G. , Fell D. , McBurney A.
Published: February 2007

Serum bupivacaine concentrations were measured in 12 children who underwent elective herniotomy and who received analgesia in the form of wound infiltration. Mean (SD) peak concentration was 0.36 (0.14) μg/ml and time to peak concentration was 14.6 (7.2) minutes after infiltration of 1.25 μg/kg of bupivacaine. These concentrations are lower than those associated with other local anaesthetic blocks and well below potentially toxic levels. Wound infiltration provides a simple, effective and safe method of providing postoperative analgesia for hernia repair in children.
The ‘cuff‐leak’ test for extubation
Authors: Fisher M. McD. , Raper R. F.
Published: February 2007

The ‘cuff‐leak’ test, which involves demonstrating a leak around a tracheal tube with the cuff deflated, has been advocated to determine the safety of extubation in patients with upper airway obstruction. In 62 such patients we were able safely to extubate all patients with a cuff leak. Two patients extubated without cuff leak required reintubation and in five patients who repeatedly failed the test, tracheostomy was performed. Subsequently, we extubated 10 patients who were stable on spontaneous ventilation and did not have cuff leak; three later required tracheostomy and seven were uneventfully extubated. While the presence of cuff leak demonstrates that extubation is likely to be successful, a failed cuff‐leak test does not preclude uneventful extubation and if used as a criterion for extubation may lead to unnecessarily prolonged intubation or to unnecessary tracheostomy.
Initial evaluation of an intracorporeal oxygenation device
Authors: COCKROFT S. , KUO J. , COLVIN M. P. , LEWIS C. T. , INNIS R. F. , WITHINGTON P. S.
Published: February 2007

We describe a recently developed intracorporeal gas transfer device, its potential applications and hazards. To date, patients with potentially reversible respiratory failure have been treated with controlled oxygen therapy and positive pressure ventilation, but this treatment may itself contribute to lung parenchymal damage from barotrauma and oxygen toxicity. Total or partial extracorporeal gas exchange can be used to reduce these risks, but this treatment is complex and has significant morbidity and mortality. This gas exchange device has been designed to provide partial gas transfer with simplicity of insertion and use. The oxygenator lies in the vena cava to provide prepulmonary gas exchange. In preliminary studies with three calves we have shown that the device increases both mean mixed venous and arterial oxygen content and reduces mean arterial carbon dioxide tension.
Pipecuronium versus high dose vecuronium
Authors: HARROP‐GRIFFITHS W. , PLATT M. , HIRSCH N. , FELDMAN S.
Published: February 2007

The onset time and tendency to cumulation of pipecuronium and high‐dose vecuronium were compared during nitrous oxide anaesthesia supplemented with a propofol infusion. Pipecuronium 0.06 mg·kg−1 had a similar duration of action to vecuronium 0.2 mg·kg−1 (49 vs 43). Patients who received vecuronium had a shorter onset time of neuromuscular blockade (p < 0.01). Neither pipecuronium nor vecuronium showed marked cumulation.
Suprascapular nerve block
Authors: WASSEF M. R.
Published: February 2007

A new approach for the management of frozen shoulder associated with reflex sympathetic dystrophy is presented. A suprascapular nerve block was performed by needle insertion behind the lateral end of the clavicle at its junction with the insertion of the trapezius muscle; the needle was directed downwards and backwards. The suprascapular nerve was identified by its response to nerve stimulation. Three ml of 0.25% bupivacaine with 1:200 000 adrenaline was injected. The block was repeated twice weekly for a total of 2–4 treatments. Evaluation of the efficacy of the block was achieved by comparing subjective pain scores and passive range of movement before the first block and after the final one. Highly significant improvements were obtained. The choice of blockade of the suprascapular nerve is a new concept for the management of the frozen shoulder of reflex sympathetic dystrophy. This is based on the fact that the nerve contains a high proportion of sympathetic fibres supplying the shoulder joint. The new approach proved to be simple, highly successful, and reproducible.
Rapidly progressive laryngeal oedema associated with pregnancy‐aggravated hypertension
Authors: ROCKE D. A. , SCOONES G. P.
Published: February 2007

We report a patient with pregnancy‐aggravated hypertension who developed rapid progression of laryngeal oedema intra‐operatively and in whom airway obstruction occurred immediately following extubation. There were no pre‐operative signs to indicate potential airway problems.
Peripartum changes in gastric emptying
Authors: SANDHAR B. K. , ELLIOTT R. H. , WINDRAM I. , ROWBOTHAM D. J.
Published: February 2007

Applied potential tomography was ilsed to measure changes in gastric emptying during the peripartum period. Gastric emptying was measured sequentially in each of 10 healthy patients at 37–40 weeks gestation, 2–3 days postpartum and after the 6‐week postnatal assessment (control),‘Aean (SD) times to 50% emptying were 15 (6.05), 11 (5.9) and 15 (5.5) min, respectively. There was no statistically signijicant change in gastric emptying as a result of pregnancy in this group of women. Retrospective power analysis (assuming α= 0.05 and β= 0.20) shows the study design was adequate to detect a difference of 8 min.
Combined epidural/spinal anaesthesia for Caesarean section
Authors: LYONS G. , MACDONALD R. , MIKL B.
Published: February 2007

An evaluation of a 30 gauge spinal needle in a combined epidural/spinal anaesthetic technique for Caesarean section revealed a 25% failure rate of the spinal element. In this unit, no more than 4% of spinal anaesthetics might be expected to fail. One of the reasons for the higher failure rate was that, when using the Tuohy needle as an introducer, the dura was not identified. This prompted us to compare the ‘hrough‐the‐ Tuohy’ or needle within needle approach for combined epidural/spinal anaesthesia, with a technique that involved siting the epidural and spinal sequentially in separate spaces. One hundred women requiring elective Caesarean section under spinal anaesthesia were randomised into single or double space groups. The technique failed in 16% of through‐the‐needle cases, and in 4% of sequential sitings. Combined spinal/epidural anaesthesia for Caesarean section is more successful if each procedure is performed using separate spaces.
Hoarseness after tracheal intubation
Authors: JONES M. W. , CATLING S. , EVANS E. , GREEN D. H. , GREEN J. R.
Published: February 2007

The reported incidence of hoarseness following short‐term tracheal intubation varies widely. It has been reported as being permanent in 3%. This suggests that an enormous problem exists considering the numbers of patients intubated daily in the United Kingdom. A prospective study of 235 adult patients undergoing general anaesthesia in a district general hospital included 167 patients whose tracheas were intubated. Of these 167, 54 (32%) complained of hoarseness postoperatively. All but five returned to normal within 7 days. The others were hoarse for 9, 10, 12, 54 and 99 days. Those who were hoarse for 54 and 99 days had vocal cord granulomata. Regression analyses showed that certain patient and anaesthetic factors had a significant effect on the hoarseness. This study confirms a low incidence of prolonged or permanent hoarseness following short‐term tracheal intubation.
Cardiovascular responses to insertion of the laryngeal mask
Authors: WILSON I. G. , FELL D. , ROBINSON S. L. , SMITH G.
Published: February 2007

We have compared, in 40 healthy patients, the cardiovascular responses induced by laryngoscopy and intubation with those produced by insertion of a laryngeal mask. Anaesthesia was induced with thiopentone and maintained with enflurane and nitrous oxide in oxygen; vecuronium was used for muscle relaxation. Arterial pressure was measured with a Finapres monitor. The mean maximum increase in systolic arterial pressure after laryngoscopy and tracheal intubation was 51.3% compared with 22.9% for laryngeal mask insertion (p < 0.01). Increases in maximum heart rate were similar, (26.6% v 25.7%) although heart rate remained elevated for longer after tracheal intubation. We conclude that insertion of the laryngeal mask airway is accompanied by smaller cardiovascular responses than those after laryngoscopy and intubation and that its use may be indicated in those patients in whom a marked pressor response would be deleterious.
Neurological sequelae in children after prolonged propofol infusion
Authors: TROTTER C. , SERPELL M. G.
Published: February 2007

Neurological sequelae occurred in two children after the withdrawal of an infusion of propofol administered during admission to the Intensive Care Unit for respiratory tract obstruction.
Resistance and additional inspiratory work imposed by the laryngeal mask airway
Authors: BHATT S. B. , KENDALL A. P. , LIN E. S. , OH T. E.
Published: February 2007

Laryngeal mask airways and tracheal tubes were studied to determine both their resistance to constant gas flows and additional inspiratory work during simulated inspiration. Laryngeal mask airways imposed less resistance and required lower additional inspiratory work compared with the corresponding sized tracheal tubes. If inspiratory loading during anaesthesia is an important consideration, then the laryngeal mask airway may be preferable to a tracheal tube.
Upper oesophageal sphincter pressure and the intravenous induction of anaesthesia
Authors: VANNER R. G. , PRYLE B. J. , O'DWYER J. P. , REYNOLDS F.
Published: February 2007

The upper oesophageal sphincter can prevent regurgitation of oesophageal contents into the pharynx following gastro‐oesophageal reflux in the awake patient. Upper oesophageal sphincter pressure was recorded with a Dent sleeve after hypnosis with midazolam (n = 7) and also during the rapid intravenous induction of anaesthesia with thiopentone (n = 16) or ketamine (n = 7). Thiopentone decreased mean(SD) sphincter pressure from an awake value of 43(19) to 9(7) mmHg (p < 0.001) and midazolam from 38(25) to 7(3) mmHg (p<0.02). Mean(SD) sphincter pressures before and after ketamine were not significantly different at 29(15) and 32(21) mmHg respectively. After suxamethonium mean(SD) sphincter pressure in all patients (n = 30) was 7(4) mmHg. Laryngoscopy (n = 30) caused a small increase in mean(SD) sphincter pressure to 13(10) mmHg (p < 0.001). Thiopentone caused a rapid fall in upper oesophageal sphincter pressure which usually started before loss of consciousness. These findings have implications for the timing of cricoid pressure application.
Patient‐controlled analgesia
Authors: GROVER E. R. , HEATH M. L.
Published: February 2007

A patient received a massive overdose of papaveretum intravenously (estimated to be 180 mg) when the glass syringe of a patient‐controlled analgesia machine disengaged from the drive mechanism. She was successfully resuscitated. The pump, on loan from the supplier, had passed a brief evaluation by the infusion pump test house designated by the Medical Devices Directorate of the Department of Health; it has since been withdrawn. It is recommended that patient‐controlled analgesia equipment should be placed at or below patient heart level. The Department of Health is called on to institute a full, independent evaluation scheme for patient‐controlled analgesia equipment.
The effect of music on ketamine induced emergence phenomena
Authors: Kumar A. , Bajaj A. , Sarkar Purnima , Grover V. K.
Published: February 2007

The purpose of this investigation was to assess the influence of music on emergence phenomena after ketamine anaesthesia. Fifty ASA 1 patients undergoing minor gynaecological procedures were randomly divided into two equal groups. Patients in the treated group were played music of their choice through headphones from 5 min before induction of anaesthesia to 15 min postoperatively. Although the incidence of emergence phenomena was similar in both groups the effects tended to be more pleasant and acceptable in those to whom music was played. The majority of patients in the study group (80%) expressed their willingness to have a similar anaesthetic in the future compared to 52% in the control group (p < 0.05).
The absence of teratogenic effects of some analgesics used in anaesthesia
Authors: MARTIN L.V.H. , JURAND A.
Published: February 2007

The possibility exists that agents used in anaesthesia may have adverse teratogenic effects on staff, patients, and developing fetuses. It has been shown that a range of neurotropic drugs, when injected into pregnant mice on the 9th day of gestation, produce a characteristic group of central nervous system malformations in their fetuses. We have studied the possible teratogenicity ofpethidine, fentanyl, phenoperidine and lignocaine when tested in this way and conclude that they appear to have less effect than other neurotropic drugs previously tested.
Anaesthesia for intraperitoneal hyperthermic perfusion
Authors: SUDARSHAN G. , CRAWFORD D.
Published: February 2007

Intraperitoneal hyperthermic perfusion is a method of regional chemotherapy shown to be effective in the prevention and treatment of peritoneal metastases. General anaesthesia for a patient who required this procedure is described. Guidelines for management are suggested, with particular emphasis on temperature control, fluid and electrolyte balance and postoperative care.