bluuebunny/crossref_metadata_2025 huggingface dataset:
The Laerdal pocket mask: effects of increasing supplementary oxygen flow
Authors: Thomas A. N. , Hyatt J. , Chen J. L. , Barker S. J.
Published: February 2007

To determine the effect of increasing supplementary oxygen flow during ventilation with the Laerdal pocket mask 24 subjects ventilated a modified recording mannikin for four 90 s periods using the mask with oxygen flows of 5 l, 10 l, 15 l and 20 l.min−1. Oxygen concentration increased and carbon dioxide concentration decreased with increasing oxygen flow. Tidal volume also increased with oxygen flow. The delivered oxygen concentrations were lower than previously reported at all four rates; however, mask function improved with increasing flow up to 20 l.
Use of adrenaline in obstetric analgesia
Authors: Holdcroft A.
Published: February 2007

A questionnaire on the use of adrenaline in obstetric analgesia was completed by 87 obstetric anaesthetists: 71% of consultants in teaching hospitals were prepared to use adrenaline mixed with local anaesthetics compared with 33% of consultants in district hospitals; they had a similar duration of obstetric anaesthetic experience. Test doses containing adrenaline were not commonly used in labour, but were more often used prior to elective Caesarean section. Adrenaline was used with either lignocaine or bupivacaine; few consultants used both solutions. Contraindications to the use of adrenaline in the nonuser group were in decreasing order of rank: neurological damage, pregnancy‐induced hypertension, stenotic valvular heart disease, sickle cell disease or trait and fetal distress. Overall, the contraindications related to the systemic absorption of adrenaline were most common.
Modified parallel ‘Lack’ breathing system for use in dental anaesthesia
Authors: Blumgart C. H. , Hargrave S. A.
Published: February 2007

A twin‐lube breathing system for inhalational anaesthesia in dental surgery is described. The system is a modification of a parallel Mapleson ‘A’ breathing system and is suitable for use with continuous flow anaesthetic machines. Resistance to airflow has been evaluated and is within the recommended ranges at all flows likely to be experienced in normal clinical conditions. The system is suitable for children and adults, easy to use and efficient. The expiratory valve is located remote from the face and the system is suitable for scavenging by active, assisted or passive systems.
The Gulf war: anaesthetic experience at 32 Field Hospital Department of Anaesthesia and Resuscitation
Authors: Adley R. , Evans D. H. C. , Mahoney P. F. , Riley B. , Rodgers C. R. , Shanks T. , Skinner T. A. , Swinhoe C. F. , Yoganathan S.
Published: February 2007

The organisation and the workload of the anaesthetic department of a Field Hospital deployed during the Gulf war were described. Suggestions are made as to how the problems encountered might be overcome in the future.
Regurgitation and oesophageal rupture with cricoid pressure: a cActaver study
Authors: VANNER R. G. , PRYLE B. J.
Published: February 2007

The efficacy of cricoid pressure was studied in 10 adult cActavers. The oesophageal pressure that would result in regurgitation during measured values of cricoid pressure was determined. Oesophageal pressure, recorded by a 2 mm diameter oesophageal tube, was increased by oesophageal distension with saline, and incremental levels of cricoid force, 20, 30 and 40 Newtons, were applied with a cricoid yoke. With each 10 Newton increment of cricoid force there was a significant rise in the oesophageal pressure required to provoke regurgitation (p < 0.01). Thirty Newtons of cricoid force prevented regurgitation of saline in all cActavers with oesophageal pressures of up to 40 mmHg. Rupture of the oesophagus occurred in three cActavers: one at 30 and two at 40 Newtons of cricoid force, but there was no rupture at 20 Newtons of cricoid force. In the other seven cActavers oesophageal pressures were also studied with a 4.6mm diameter (14 FG) oesophageal tube, which did not reduce the efficacy of cricoid pressure in preventing regurgitation.
Continuous extradural infusion of lignocaine 0.75% vs bupivacaine 0.125% in primiparae: quality of analgesia and influence on labour
Authors: MILASZKIEWICZ R. , PAYNE N. , LOUGHNAN B. , BLACKETT A. , BARBER N. , CARLI F.
Published: February 2007

We studied 86 primiparous women with uncomplicated pregnancy and labour requesting extradural analgesia in labour. All the women were over 36 weeks of gestation with a cephalic‐presenting singleton fetus. The women were allocated randomly to two groups: group A, who received an extradural infusion of lignocaine 0.75%, after an initial dose of 10 ml of lignocaine 1.5%, and group B, who received an infusion of bupivacaine 0.125% after an initial dose of 10 ml of bupivacaine 0.25%. All the women had their labour actively managed. Assessment of analgesia during labour and delivery, and the requirements for additional top‐ups were noted, as were mode of delivery, requirement for oxytocic augmentation and incidence of fetal distress. Maternal and umbilical cord plasma concentrations of lignocaine were measured at delivery in 12 women receiving extradural lignocaine. There were no statistically significant differences between the two groups in terms of the mode of delivery, incidence of fetal distress, fetal heart rate abnormalities, or Apgar scores of the babies. Women in the bupivacaine group had a significantly better quality of analgesia during both the first and second stages of labour (p = 0.0005) and required fewer top‐ups than those in the lignocaine group. However, the requirement for oxytocin augmentation during the first and second stages of labour was significantly less in the lignocaine group (p = 0.004). Similarly, the duration of the second stage was shorter compared with the bupivacaine group. In spite of high plasma concentrations of lignocaine, no side effects were noted in either mothers or babies.
An assessment of an alternative method of internal jugular vein catheterisation
Authors: Latto I. P. , Hughes J. A. , Falconer R. J.
Published: February 2007

This study assessed a tried, but previously unpublished, method of internal jugular vein cannulation in 50 patients scheduled for elective cardiac surgery. The method involves using two landmarks: the larynx (thyroid and cricoid cartilages) together with the carotid artery (if it is palpable). The cricoid and thyroid cartilages were readily identifiable in 48 (96%) patients. The carotid artery was palpable in 45 (90%) patients, although some difficulty in palpation was recorded in 24 (48%) patients. There was a 98% success rate of venous cannulation. In 90% of cases the 21 gauge seeker needle entered the vein on the first or second attempt, and in 82% of cases the subsequent 18 gauge introducing needle entered the vein on the first attempt.
Phantom limb pain during labour
Authors: DUREJA G. P. , SANDHYA G. P.
Published: February 2007

We report the occurrence of severe phantom limb pain during labour. The patient, a 27‐year‐old, had had an above knee amputation performed 6 years earlier following a road traffic accident but had no previous history of phantom limb phenomena. However, during early labour, she complained of a severe phantom limb pain in her amputated leg; a continuous epidural block relieved her of the sensation and pain. The sensation did not return following delivery.
A comparison of propofol and methohexitone for dental chair anaesthesia in children
Authors: Ewah B. , Carr C.
Published: February 2007

Fifty healthy children presenting for outpatient exodontia received either propofol or methohexitone for induction. Anaesthesia was maintained in both groups using 50% oxygen in nitrous oxide and 1–2% halothane. Those receiving methohexitone maintained a significantly higher mean arterial pressure and heart rate than the propofol group. Nine percent of patients in the propofol group developed ventricular arrhythmias, compared to 32% in the methohexitone group.
The level of neuromuscular block needed to suppress diaphragmatic movement during tracheal suction in patients with raised intracranial pressure: a study with vecuronium and atracurium
Authors: WERBA A. , KLEZL M. , SCHRAMM W. , LANGENECKER S. , MULLER C. , GOSCH M. , SPISS C. K.
Published: February 2007

The effects of tracheobronchial suction before and after neuromuscular blockade with vecuronium (0.12 mg.kg−1; ED95 X 2; group A) and atracurium (0.4 mg.kg−1; ED95 X 2; group B) on intracranial pressure were studied in 18 neurosurgical patients with a Glasgow Coma Scale < 7. Despite adequate sedation, moderate to severe diaphragmatic movements (bucking and coughing) in response to carinal stimulation with significant increases in intracranial pressure (A: 18 SD 7 to 24 SD 8 mmHg; B: 19 SD 7 to 27 SD 5 mmHg) and subsequent decreases in cerebral perfusion pressure (group A: 69 SD 11 to 63 SD 8 mmHg; group B: 63 SD 11 to 59 SD 17 mmHg) could be observed without muscle relaxation. After a bolus dose of vecuronium or atracurium, profound neuromuscular paralysis quantified by the post‐tetanic count, was observed after an onset time of 253 SD 72 s (vecuronium) and 159 SD 54 s (atracurium). Slight diaphragmatic movements could be elicited in only two patients in group A and in two patients in group B during tracheal suction; intracranial pressure (group A: 20 SD 8 to 20 SD 8 mmHg; group B: 19 SD 7 to 19 SD 7 mmHg) and cerebral perfusion pressure (group A: 65 SD 13 to 65 SD 13 mmHg; group B: 66 SD 12 to 65 SD 11 mmHg) remained unchanged. When coordinating respiratory therapy in neurosurgical intensive care patients, profound neuromuscular block, quantified by a post‐tetanic count of at least 5 for vecuronium and 1 for atracurium, it is necessary to rule out any impact of diaphragmatic movement on intracranial pressure. Repeated neurological evaluation was not inhibited when utilising an intermittent bolus‐dose regimen.
A comparison of percutaneous and perconjunctival routes of administration of peri‐ocular anaesthesia for day case cataract surgery
Authors: Sweeney E.J. , Barber K. , Prosser J.A.
Published: February 2007

This study of 100 day case patients having cataract surgery under local anaesthesia compared patient acceptance of two peri‐ocular techniques; a transcutaneous method and a transconjunctival method. A significant difference was found in relation to the pain felt on injection such that all peri‐ocular blocks at our unit are now done via the perconjunctival route.
Hyperthermia associated with 3,4‐methylenedioxyethamphetamine (‘Eve’)
Authors: TEHAN B. , HARDERN R. , BODENHAM A.
Published: February 2007

A patient was admitted with hyperthermia, muscle rigidity, rhabdomyolysis and disseminated intravascular coagulation. He was initially thought to have taken 3,4‐methylenedioxymethamphetamine (MDMA, ‘Ecstasy’), but subsequent toxicology revealed the presence of 3,4‐methylenedioxyethamphetamine (MDEA, ‘Eve’), its sister drug, in his blood. Subsequent in vitro testing for malignant hyperthermia proved to be negative.
Severe bronchospasm during epidural anaesthesia
Authors: WANG C. Y. , ONG G. S. Y.
Published: February 2007

A case of severe bronchospasm occurring during epidural anaesthesia in a patient undergoing Caesarean section is described. The aetiology of the bronchospasm may have been related to sympathetic nervous blockade allowing unopposed parasympathetically mediated bronchoconstriction.
An evaluation of anaesthetic loss from a closed breathing system
Authors: LOCKWOOD G. G. , CHAKRABARTI M. K. , WHITWAM J. G.
Published: February 2007

We present the results of a laboratory study of the loss of isoflurane from a to‐and‐fro system, ventilated with oxygen, using a standard ventilator connected to the system via a long corrugated tube (the trunk) in place of the reservoir bag. No conventional fresh gas supply is used and isoflurane is injected as a liquid directly into the soda lime canister. The loss of isoflurane from the system due to mixing in the trunk was generally less than that lost by absorption into rubber and plastic system components. Glass syringes used for injection of liquid isoflurane were found to be a potential source of much greater leaks. The results showed that a to‐and‐fro system ventilated with oxygen via an open trunk functions as a virtually completely closed anaesthetic breathing system.
Histamine release following atracurium in the elderly
Authors: SHORTEN G. D. , GOUDSOUZIAN N. G. , ALI H. H.
Published: February 2007

A study was performed to evaluate histamine release, as well as potential cardiovascular and cutaneous sequelae, following bolus administration of atracurium in elderly patients. In 15 patients, using a radioenzymatic technique, plasma histamine concentrations were measured in venous blood samples obtained before and after induction of anaesthesia with thiopentone and at 2 and 5 min after administration of atracurium (0.6 mg.kg−1) over 30 s. Blood pressure and pulse rate were measured noninvasivefy and cutaneous changes sought and compared with those seen in 12 similar patients who received vecuronium (0.1 mg.kg−1). Our findings indicate that the histamine releasing property of atracurium in elderly patients is greater than that in children, similar to that in adolescents and less than that in nonelderly adults. The decreases in blood pressure following atracurium and vecuronium in elderly patients are similar.
The effect of residual receptor occupancy on sensitivity to repeated vecuronium
Authors: CAMPKIN N. T. A. , HOOD J. R. , FAUVEL N. J. , FELDMAN S. A.
Published: February 2007

Cumulative dose‐response curves were obtained for vecuronium in 10 patients anaesthetised with thiopentone, enflurane and nitrous oxide using adductor pollicis mechanomyography. Five patients received vecuronium systemically, which was repeated at 100% twitch recovery to obtain initial and repeat curves. Another five patients received 0.3 mg vecuronium into an isolated forearm and at 100% recovery of this arm received vecuronium systemically to obtain simultaneous dose‐response curves in both the previously isolated and nonisolated arms. There was no significant difference between the calculated ED50 obtained after initial systemic administration [16.2 (1.7) μg.kg−1], after recovery in the previously isolated arm [14.8 (2.0) μg.kg−1] and simultaneously in the nonisolated arm [16.1 (2.9) μg.kg−1]. The ED50 obtained after repeated systemic administration was significantly reduced [8.2 (2.9) μ.kg−1]. These results suggest that the reduction in ED50 at 100% twitch recovery from systemic vecuronium is not due to residual drug at the biophase/receptor but to drug persisting in the plasma.
The management of anaesthesia for Caesarean section in a patient with paroxysmal ventricular tachycardia
Authors: FIELD L. M. , BARTON F. L.
Published: February 2007

We describe the successful management of general anaesthesia for Caesarean section in a patient with poorly controlled paroxysmal ventricular tachycardia of pregnancy. The use of alfentanil before laryngoscopy and tracheal extubation ensured cardiostability without compromising maternal or fetal wellbeing. General anaesthesia allows prompt cardioversion. We believe that in the presence of a life‐threatening unstable cardiac rhythm this consideration outweighs any theoretical advantage of regional blockade.
The additional work of breathing imposed by Mapleson A systems
Authors: OOI R. , PATTISON J. , Soni N.
Published: February 2007

The additional work attributable to breathing through five Mapleson A anaesthetic breathing systems (Magill, Lack, Parallel Lack, Humphrey ADE and Enclosed Magill) was studied using a lung model. With all five systems, the additional work was found to be a function of fresh gas flow, respiratory flow as well as system geometry. Within the range of fresh gas flow and respiratory flows studied, the additional work ranged between 80 mJ.1−1 and 182 mJ.1−1. Expiratory work was always greater than the inspiratory workload, increasing fresh gas inflow into the system increases expiratory work, both resistive and elastic components. The Magill system posed the least work expenditure. The values for the additional work obtained with the lung model were of the same order of magnitude when measurements were taken in volunteers.
A comparison of the effect on gastric emptying of alfentanil or morphine given during anaesthesia for minor surgery
Authors: Bennett M. W. R. , Shah M. V. , Bembridge J. L.
Published: February 2007

Twenty patients, scheduled for minor gynaecological surgery, were studied. Anaesthesia was induced with propofol and maintained with oxygen, nitrous oxide and enflurane. Patients were randomly allocated to two groups: group 1 were given alfentanil 0.2 mg; group 2 were given morphine 5 mg. The rate of gastric emptying was measured indirectly by the paracetamol absorption technique. The results showed that morphine caused greater delay in gastric emptying compared with alfentanil (p < 0.05). The observed effect on gastric emptying rate may potentially affect the risk of peri‐operative regurgitation and aspiration. This study provides further evidence that in short day‐case procedures, when oral medication may be required postoperatively, alfentanil may be preferable to morphine as an intra‐operative opioid.
Continuous regional analgesia in comparison with intravenous opioid administration for routine postoperative pain control
Authors: Schug S. A. , Fry R. A.
Published: February 2007

This study compares retrospectively the postoperative analgesia provided via intravenous opioids with continuous regional techniques (interpleural and epidural infusions) administered as a clinical routine by an anaesthesia‐based Acute Pain Service. In 2630 patients no severe complications resulting in morbidity or mortality occurred; the rate of potentially serious complications was in the 0.5% range and comparable between the techniques. A detailed analysis of a randomised subsample of 340 patients revealed better analgesia at rest and better compliance with physiotherapy under continuous regional analgesia. Techniques of continuous regional analgesia also resulted in fewer incidents of desaturation and fewer side effects. Patient satisfaction with these techniques was higher than with intravenous opioid administration. In conclusion, continuous regional analgesia in a routine clinical setting is comparable to intravenous opioid administration with regard to safety, but results in significantly better analgesia with fewer side effects.
A comparison of 25 G and 27 G Whitacre needles for Caesarean section
Authors: SMITH E. A. , THORBURN J. , DUCKWORTH R. A. , REID J. A.
Published: February 2007

Spinal needles with a pencil‐point tip and those of a finer gauge are known to be associated with a lower incidence of postdural puncture headache. This study set out to determine if fine pencil‐point needles were acceptably easy to use in routine clinical practice. Two hundred and twelve women undergoing elective Caesarean section were randomly allocated to receive a subarachnoid block using either a 25 G or 27G Whitacre needle. Factors determining ease of needle use, adequacy of block, incidence of postdural puncture headache, backache and neurological sequelae were assessed. Successful intrathecal injection was achieved in all patients in the 25 G group. Using the 27 G needle, the anaesthetist failed to reach the subarachnoid space in eight patients of which seven subsequently had a successful intrathecal injection with a larger needle. These failures were attributed to excessive needle flexibility which was the only significant difference in ease of use between the 25G and 27G needles. In the 25G group, there was one severe postdural puncture headache which required an epidural blood patch and three mild headaches which resolved spontaneously. There were no postdural puncture headaches in the 27 G group. We conclude that the final choice of needle is a compromise between the ease of use and lower failure rate of the 25 G needle and the, as yet unproven, possibility of a lower incidence of postdural puncture headache with the 27 G needle.
Administration of rocuronium (Org 9426) by continuous infusion and its reversibility with anticholinesterases
Authors: McCOY E.P. , MIRAKHUR R.K. , MADDINENI V.R. , LOAN P.B. , CONNOLLY F.
Published: February 2007

The use of rocuronium (Org 9426) as a single bolus followed by an infusion was assessed in 50 patients under anaesthesia with nitrous oxide‐oxygen and halothane. Neuromuscular block was monitored using train‐of‐four stimulation and recording the force of contraction of the adductor pollicis muscle. Rocuronium was administered in an initial bolus dose of 0.45 mg.kg‐1 followed by an infusion adjusted manually to maintain the T1, the first response in the train‐of‐four, at 10% of control. Following cessation of rocuronium infusion the patients were either allowed to recover spontaneously (n = 10) or were given neostigmine 50μg.kg‐1 or edrophonium 1 mg.kg‐1 at 10 or 25% recovery of the T1 (n = 10 for each group). Adequate antagonism was defined as attaining a sustained train‐of‐four ratio of 0.7. Rocuronium requirements showed marked variation among individual patients but were relatively constant in individual patients. The mean (SD) time to attain stable infusion rates was 17.4 (10.9) min. The mean (SD) requirement of rocuronium for steady state 90% block of T1 was 572 (190) μg.kg‐1.h‐1 (range 242–1104 μg.kg‐1.h‐1). The mean (SD) time to attain a train‐of‐four ratio of 0.7 in the group allowed to recover spontaneously was 36.1 (7.3) min. This interval was 7.5 (1.9), 9.3 (7.0), 4.6 (1.9) and 1.9 (0.9) min respectively in the groups receiving neostigmine at T1 of 10%, edrophonium at T1 of 10%, neostigmine at T1 of 25% and edrophonium at T1 of 25%. The antagonism was significantly faster in those reversed at 25% (p < 0.05). Three patients in the group receiving edrophonium at T1 of 10% and one in the group receiving neostigmine at T1 of 25% failed to attain a train‐of‐four ratio of 0.7. It is concluded that rocuronium can be administered as a continuous infusion for stable neuromuscular block. Neostigmine may be a more reliable antagonist of deep block, whereas edrophonium is advantageous when there is a greater spontaneous recovery.
Neuromuscular blockade of the fetus with pancuronium or pipecuronium for intra‐uterine procedures
Authors: FAN S. Z. , SUSETLO L. , TSAI M. C.
Published: February 2007

Fetal movement during intra‐uterine fetal therapy makes these procedures technically more dificult and increases the likelihood of trauma to the fetus. Pancuronium or pipecuronium were used in a randomised study to temporarily arrest movement in 16 fetuses undergoing intra‐uterine procedures. Under ultrasound guidance, pancuronium or pipecuronium 0.2 mg.kg−1 was injected into the fetal gluteal region. Fetal movements ceased within 4.6 ± 2.3 min in the pancuronium group and 4.5 ± 2.8 min in the pipecuronium group and returned by 115±26 min in the pancuronium group and 121 ± 3 2 min in the pipecuronium group. No adverse effects of the relaxant were observed in the mothers. There bvas no evidence of soft tissue, nerve or muscle damage at the fetal injection site after delivery. Both muscle relaxants provided a safer method for diagnostic and therapeutic procedures. However, four cases in the pancuronium group (50%) developed a fetal tachycardia, and two cases in the same group showed loss of beat‐to‐beat variability. Pipecuronium appeared to be more suitable for intra‐uterine procedures.
Prolonged high frequency jet ventilation and milrinone therapy following modified Fontan procedure
Authors: McBRIDE W. T. , McMURRAY T. J.
Published: February 2007

An 11‐year‐old boy who underwent a modified Fontan procedure required surgical re‐exploration the next day. Profound cardiogenic shock developed and he required high frequency jet ventilation and milrinone therapy for 15 days. After 11 days of high frequency jet ventilation he developed a tracheal mucous plug leading to a hypoxic cardiac arrest from which he was successfully resuscitated.
Teaching fibreoptic intubation in anaesthetised patients
Authors: Schaefer H. G. , Marsch S.C.U. , Keller H. L. , Strebel S. , Anselmi L. , Drewe J.
Published: February 2007

One hundred ASA grade 1 and 2 patients requiring orotracheal intubation for various general surgical procedures were randomly assigned to receive either expert rigid laryngoscopic or novice fibreoptic orotracheal intubation under total intravenous anaesthesia. Five anaesthesia residents in the 4th year, with no prior experience in fibreoptic laryngoscopy, participated in a fibreoptic training course, viewing two instructional videos and practising on the intubation manikin. Each resident intubated 20 patients in a randomised fashion either as an expert laryngoscopist or as a fibreoptic novice. The time (SEM) to achieve successful intubation was statistically different for fibreoptic and rigid intubation (77.2 (5.1) s vs 17.7 (1.6) s, p < 0.01). The time to achieve successful rigid laryngoscopic intubation remained constant over the ten intubations, whereas time required for fibreoptic intubation decreases significantly (p < 0.01). The learning objectives (fibreoptic intubation times in 60 s or less and with 90% or greater success rate on the first intubation attempt) were met by all residents. The haemodynamic profile was similar for fibreoptically intubated and conventionally intubated patients and there was no difference between the first two or the last two fibreoptive or rigid intubations. The study was designed to detect a difference of 10% in means (assuming β= 0.05 and 0.2). The incidence of postoperative sore throat, dysphagia or hoarsensess was similar in both groups. We conclude that routine fibreoptic orotracheal intubation in ASA grades 1 and 2 surgical patients is justifiable for teaching this valuable technique. since it increases clinical exposure to fibreoptic intubation, which should be learned and mastered by all anaesthetic residents by completion of their residency.
The incidence and severity of postoperative nausea and vomiting in patients exposed to positive intra‐operative suggestions
Authors: Williams A. R. , Hind M. , Sweeney B. P.
Published: February 2007

In a double‐blind study, the effects of positive intra‐operative suggestions on the incidence and severity of postoperative nausea and vomiting were studied in 60 patients randomly selected to undergo routine major gynaecological surgery. Patients who received positive suggestions suffered significantly less nausea and vomiting in the 24 h after surgery.
Review of uses of the laryngeal mask in ENT anaesthesia
Authors: Nair I. , Bailey P. M.
Published: February 2007

A review of the various uses of the laryngeal mask in otorhinolaryngological surgery is presented. Its primary use is in airway management, especially during recovery from anaesthesia.
Pressure support ventilation during isoflurane anaesthesia
Authors: BHATT S. B. , CHUI P. T. , GIN T. , TAM Y. H. , OH T. E.
Published: February 2007

We have studied the respiratory effects of 5and 10cmH2O pressure support ventilation during anaesthesia with 1.5% end‐tidal concentration of isoflurane in nine healthy, spontaneously breathing, adult patients. Some of the patients demonstrated an irregular respiratory pattern with periods of apnoea and we therefore went on to study a further seven patients with a continuous 500 s recording of airflow. Pressure support ventilation augmented mean (SD) tidal volume from 212 (56) ml to 360 (88) ml at 5 cmH2O and to 509 (108)ml at 10cmH2O (n = 16, p < 0.05). Mean (SD) respiratory rate decreased from 26 (6)min‐1 to 22 (6)min‐1 at 5cmH2O and 17(5)min‐1 at 10 cmH2O pressure support (n = 16, p < 0.05). Mean (SD) inspiratory work of breathing decreased from 1.77 (0.70) J.min‐1 to 0.31 (0.36) J.min‐1 at 5 cmH2O and 0.16 (0.26) J.min‐1 at 10cmH2O pressure support ventilation (n = 9, p < 0.05). Analysis of the respiratory rhythm in the second group of seven patients revealed an oscillating respiratory pattern in four patients at 5cmH2O and six of the seven patients at 10 cmH2O pressure support ventilation. The metabolic advantage of the decreased work of breathing during pressure support ventilation during anaesthesia is unlikely to balance the disadvantage of an oscillating respiratory rhythm.
Gastric regurgitation during general anaesthesia in different positions with the laryngeal mask airway
Authors: EL MIKATTI N. , LUTHRA A. D. , HEALY T. E. J. , MORTIMER A. J.
Published: February 2007

Ninety patients, divided into three groups of 30, were investigated to determine the incidence of gastric regurgitation during general anaesthesia administered via the laryngeal mask airway in the supine, Trendelenburg and lithotomy positions. Fifteen minutes before induction of anaesthesia each patient swallowed a 75mg methylene blue capsule. At the end of surgery, the LMA and the oropharynx were inspected for bluish discoloration which was considered to be a sign of gastric regurgitation. No blue dye was detected in the supine group but it was observed in one patient in each of the other two groups.
The influence of anaesthetic technique upon the immune response to hysterectomy
Authors: PIRTTIKANGAS C‐O. , SALO M. , MANSIKKA M. , GRÖNROOS J. , PULKKI K. , PELTOLA O.
Published: February 2007

Earlier studies on propofol have shown increased percentages of T helper cells after minor surgery. In this study, the effects of propofol infusion anaesthesia on the immune response were compared with those of combined isoflurane anaesthesia in 30patients (median age 47 years, ASA 1–2) undergoing major surgery. The total dose of propofol in the propofol infusion group of 15 women was 860 mg (range 540–1520 mg) and the median end‐expiratory isoflurane concentration in the combined isoflurane group of 15 women was 0.6% (range 0.5–0.8). The following were measured; leucocyte and differential counts; percentages of lymphocyte subpopulations (CDS, CD4, CD8, CD 19, CD 16 and HLA‐DR + CD3); phytohaemagglutinin‐, concanavalin A‐, and pokeweed mitogen‐induced and unstimulated lymphocyte proliferation; plasma interleukin‐6; serum group II phospholipase A2, C‐reactive protein and cortisol concentrations. Measurements were made pre‐operatively, at the end of the operation and on the first and fifth postoperative days. No statistically significant overall differences were observed in the immune response between the groups. The serum cortisol response was weaker in the propofol group than in the isoflurane group (p < 0.05). Time‐related changes were seen within the groups.
Postoperative emesis following otoplasty in children
Authors: Paxton D. , Taylor R. H. , Gallagher T. M. , Crean P. M.
Published: February 2007

Sixty unpremedicated children aged between 3 and 14 years, scheduled for otoplasty, were randomly divided into one of three groups to receive either ondansetron 0.1 mg.kg‐1, droperidol 75 μg.kg‐1, or placebo at induction of anaesthesia. All patients received a standard general anaesthetic using thiopentone, atracurium and halothane. Opioid analgesia was avoided intra‐operatively and infiltration with local anaesthetic was used prior to the start of surgery. Children who received ondansetron were less likely to vomit (15%) than those who received either droperidol (40%) or placebo (60%) (p < 0.01). This group also tolerated oral ingestion of fluids and solids earlier than those who received either droperidol or placebo (p < 0.001). There was no difference between the placebo or droperidol group in the incidence of vomiting or time to ingestion of oral fluids and meals. Three patients in the ondansetron group had a self‐terminating nodal rhythm which was not associated with any haemodynamic disturbances. Postoperatively there were no untoward incidents in any of the groups and all patients were discharged home the day after surgery.
The influence of nitrous oxide on propofol dosage and recovery after total intravenous anaesthesia for day‐case surgery
Authors: LINDEKÆR A. L. , SKIELBOE M. , GULDAGER H. , JENSEN E. W.
Published: February 2007

We studied the influence of nitrous oxide on the maintenence dose of propofol and recovery characteristics in 42 patients, aged 18–62 years, ASA 1 or 2, scheduled for day case inguinal herniotomy. Using a double‐blind, randomised design, patients received anaesthesia with propofol‐alfentanil‐vecuronium‐oxygen and either nitrous oxide or room air (Fio2= 0.30). The rate of propofol infusion was adjusted depending on anaesthetic depth as judged using standard clinical criteria; alfentanil was administered on a weight basis. Patients’ lungs were manually ventilated after tracheal intubation and muscle relaxation was reversed at the end of surgery with neostigmine and atropine. A series of psychomotor tests was performed pre‐operatively and 30 and 120min postoperatively. The mean maintenance doses of propofol were 0.084 mg .kg‐1 .min‐1 in the N2O group and 0.088 mg.kg‐1.min‐1 in the air group (p = 0.97). In the nitrous oxide group the mean (SD) interval to spontaneous eye opening was 13.1 (7.3) min compared to 8.1 (4.9)min in the air group (p = 0.01). Similarly, the interval until obtaining a standardised response was 13.5 (5.3) min and 9.8min (5.4) in the nitrous oxide and air groups, respectively (p = 0.04). The addition of nitrous oxide to propofol‐alfentanil‐vecuronium anaesthesia does not reduce propofol requirements and prolongs early recovery compared to air.
Epidural infusions of bupivacaine and diamorphine in labour
Authors: LOWSON S. M. , EGGERS K. A. , WARWICK J. P. , MOORE W. J. , THOMAS T. A.
Published: February 2007

Three different concentrations of bupivacaine, 0.125%, 0.062% and 0.031%, all with diamorphine 0.0025%, were given as an epidural infusion at 10 ml.h‐1 to 63 mothers in labour. When the three infusions were compared, significant differences were found in maternal requirements for top‐ups and the degree of motor block, but there were no differences in the pain scores. The reduced motor block was not associated with a reduction in the instrumental delivery rate.
Measurement of tidal flow using a transit‐time ultrasonic breath analyser
Authors: WILLIAMS E. M. , BURROUGH S. L. M. , McPEAK H.
Published: February 2007

The ability of the Transit‐time Ultrasonic Breath Analyser (TUBA, GHG Medical Electronics GMBH, Zürich, Switzerland) to measure peak flow and tidal volume in the laboratory was tested using a variety of flow and pressure conditions, chosen to simulate the respiratory patterns of patients receiving mechanical ventilatory support. A stable zero baseline was achieved by acoustic damping of the TUBA flow sensor head. A piston pump was used to generate sinusoidal flow pattern, with a peak flow range from 0.1 to 1.5 l.s‐1. The calculated peak flow matched the peak flow measured by the TUBA. The TUBA accurately measured tidal volumes (± 10%) delivered using three different flow patterns over a range of volumes from 0.25 to 11. We conclude, that once modified, the TUBA can provide an accurate measurement of peak flow and tidal volume over a range of values likely to be encountered during mechanical ventilation of the lungs.
Implications of chemical and physical properties of desflurane for longer surgery
Authors: WEISKOPF R. B.
Published: February 2007

Increased duration of anaesthetic administration has implications for recovery from anaesthesia, has cardiovascular effects, and potential for toxicity through metabolism and breakdown of the anaesthetics. Recovery of function after desflurane or sevoflurane anaesthesia, because of the low blood gas and tissue solubilities of these agents, is more rapid than after halothane, isoflurane or enflurane, with recovery being most rapid after desflurane. Increased duration of anaesthesia amplifies the differences in rate of recovery because of the additional anaesthetic (greater with more soluble agents) dissolved in tissues. Increased duration of anaesthesia lessens the cardiovascular depression associated with most halogenated inhaled anaesthetics including desflurane, but not isoflurane. Increased duration of anaesthesia allows for greater metabolism of anaesthetics and greater exposure to metabolites and potentially toxic breakdown products. Desflurane is the least metabolised of the available anaesthetics and is stable in soda lime and Baralyme. Thus, it has exceedingly low potential for toxicity. Sevoflurane undergoes considerable metabolism, producing free fluoride ion, with plasma concentrations proportional to dose and duration of anaesthesia exceeding 50 μM in approximately 7% of patients. In rats, the effects of a toxic breakdown product of sevoflurane, CF2=C(CF3)OCH2F (compound A), are also dose‐and duration‐dependent, with lower concentrations producing toxic effects as duration of exposure increases. The clinical importance of the metabolism and in vitro breakdown of sevoflurane has still to be adequately tested.
Malignant hyperthermia—a large kindred linked to the RYR1 gene
Authors: WALLACE A. J. , WOOLDRIDGE W. , KINGSTON H. M. , HARRISON M. J. , ELLIS F. R. , FORD P. M.
Published: February 2007

Malignant hyperthermia susceptibility is genetically heterogeneous. The ryanodine receptor gene on the long arm of chromosome 19 represents an important candidate gene but not all families with malignant hyperthermia demonstrate ryanodine receptor mutations or linkage to this region of 19q. Linkage to chromosome 17 in the region of the adult muscle sodium channel α subunit gene has been suggested in some families; others are not linked to either of these loci. For most families the in vitro muscle contracture test remains the only reliable method of predicting susceptibility to malignant hyperthermia. We have performed linkage analysis in a large family group with malignant hyperthermia in which the in vitro muscle contracture test had been carried out using the procedure standardised by the European Malignant Hyperthermia Group. None of the published ryanodine receptor gene mutations associated with malignant hyperthermia susceptibility were detected in affected individuals but linkage to intragenic ryanodine receptor markers strongly suggest that this gene is involved in malignant hyperthermia susceptibility in this family. This enabled accurate predictive testing by DNA analysis in 11 untested subjects at 50% risk.
Peri‐operative management of diabetic patients
Authors: ELDRIDGE A. J. , SEAR J. W.
Published: February 2007

Two hundred and seven anaesthetists in the Oxford region were sent a questionnaire asking about their peri‐operative management of patients with diabetes mellitus. One hundred and seventy two valid returns were received. The results of this survey were compared with those of a similar survey conducted in 1985. A greater proportion of anaesthetists in 1993 would maintain their diabetic patients with a peri‐operative blood glucose concentration of less than 10 mmol.l ‐1. Anaesthetists are more likely to be interventional in their management of diabetic patients than in 1985 and the methods used have changed in relative popularity. In 1993 diabetic patients undergoing major surgery were most commonly managed with separate infusions of insulin and glucose, while in 1985 the combined infusion of glucose, insulin and potassium was the most popular technique. The use of protocols in hospitals may increase the degree of uniformity of practice between anaesthetists.
A practical evaluation of four human‐powered portable airway aspirators
Authors: ARNSTEIN F.E.
Published: February 2007

The establishment of a clear airway is a vital part of basic life support and mechanical devices are available to assist the clearance of the upper airway during resuscitation. The performances of four human‐powered devices, currently available in the United Kingdom, were compared with the relevant British Standard. The ease of use of the devices by 20 experienced and 20 novice resuscitators was assessed. Three of the four devices met all British Standard criteria tested whereas the fourth failed on one test only. These devices are generally simple to use. However, two devices (‘Res‐Q‐Vac’and'Ambu Maxi Suction Pump’) were more user friendly. The incidence of airway contamination during resuscitation and the current recommended resuscitation protocols suggest that there is a need for increased emphasis on these airway adjuncts in life‐support training. Wider access to basic life support equipment inside and outside hospital premises may improve resuscitation outcome.
Modification of pain on injection of propofol
Authors: Lyons B. , Lohan D. , Flynn C. , McCarroll M.
Published: February 2007

One hundred and fifty ASA 1 and 2 patients were randomly allocated to receive pethidine 25 mg (1 ml), lignocaine Wing (1 ml) or 0.9% saline (1 ml) on a double‐blind basis, as pretreatment to reduce pain on injection of propofol. Both active treatments were significantly better than placebo at preventing pain (p<0.01). Lignocaine was most effective in preventing pain in men (p<0.05) whilst pethidine was more effective in women (p<0.05).
Wearing of masks for obstetric regional anaesthesia
Authors: Panikkar K. K. , Yentis S. M.
Published: February 2007

A postal survey of 801 members of the Obstetric Anaesthetists Association was carried out in the United Kingdom and Ireland to investigate the use of surgical facemasks whilst performing spinal and epidural blocks. Two hundred and twenty three out of 539 respondents (41.3%) routinely wore masks for both spinals and epidurals; 22 (4.1%) wore masks only for epidurals; 21 (3.9%) wore masks only for spinals and 273 (50.6%) did not wear masks for either spinals or epidurals. Fifty out of 240 (21%) of those who routinely wore masks did not believe that wearing a mask reduced the risk of infection. Only 83 out of 259 (32%) mask wearers changed their masks between cases.
Dose—response and minimum time to satisfactory intubation conditions after mivacurium in children
Authors: McCLUSKEY A. , MEAKIN G.
Published: February 2007

We assessed neuromuscular blocking effects and tracheal intubation conditions following mivacurium in 121 anaesthetised children aged 1–10 years. The study was conducted in three parts. Parts 1 and 2 were undertaken during thiopentone—alfentanil—nitrous oxide anaesthesia; neuromuscular blockade was evaluated by recording the force of contraction of the adductor pollicis in response to train‐of‐four stimulation at 0.I Hz. In part 1 the potency of mivacurium was determined in 15 children using a single dose‐response technique; in part 2 onset and recovery times were determined in six children following a dose of mivacurium 0.2mg.kg‐1. In part 3 of the study, clinical intubation conditions were assessed in two groups of 50 children whose tracheas were intubated 60 or 90s after injection of mivacurium 0.2mg.kg‐1 during thiopentone—nitrous oxide anaesthesia. The ED50 and ED95; of mivacurium were 54 and 105 ug.kg‐1 respectively. The times to 90% and 100% depression of control twitch were 1.3 (0.3) and 1.9 (0.5) min; times to 5%, 25%, 75% and 90% recovery were 6.4 (1.0), 8.4 (1.1), 12.5 (1.1) and 14.4 (1.9) min, respectively. Intubation conditions were rated satisfactory in 33/50 children (0.66, 95% confidence interval 0.51–0.79) at 60s and in 49/50 children (0.98, 95% confidence interval 0.89–1.0) at 90s (p = 0.0001). Intubation conditions 90s after mivacurium 0.2mg.kg‐1 were significantly better than those obtained in 10 patients given anaesthetic drugs alone (p = 0.002).
The importance of the expiratory pause
Authors: COOK L. B.
Published: February 2007

A physical lung model simulating spontaneous respiration was used to investigate the influence of the respiratory pattern on the efficiency of the Mapleson A, C and D breathing systems. It is shown that the Mapleson A system is always the most efficient breathing system and that its performance is relatively independent of the respiratory pattern. When the expiratory pause is minimal, the Mapleson C system is almost as efficient as the Mapleson A, but becomes ever less efficient as the expiratory pause increases. The Mapleson D system is very inefficient when the expiratory pause is short. With a longer expiratory pause, this system's efficiency approaches that of the Mapleson A. The experimental results are compared with predictions generated by a mathematical model. There is good agreement between the two, validating the mathematics used.
Anaesthesia for Cockayne syndrome
Authors: Wooldridge W. J. , Dearlove O. R. , Khan A. A.
Published: February 2007

Cockayne syndrome is a rare autosomal recessive condition producing a dwarfed, mentally retarded infant or child. Problems with airway management and an increased risk of gastric aspiration are the main anaesthetic concerns. Anaesthetics given to three patients with Cockayne syndrome are described. In two of these, tracheal intubation was difficult and the use of a laryngeal mask airway proved invaluable.
Changing the management of low‐back and nerve‐damage pain
Authors: DAVIES H. T. O. , CROMBIE I. K. , MACRAE W. A. , ROGERS K. M. , CHARLTON J. E.
Published: February 2007

This audit study took place in ten outpatient pain clinics and focused on the management of low back pain and nerve‐damage pain. The objective was to identify and promote appropriate changes in management. An analysis of the treatment of 1236 patients with low back pain and/or nerve‐damage pain highlighted wide variations in practice. Presentation of these data to the clinics was used as a means of promoting change. Data on a further 1791 patients were used to assess the extent of any changes in practice. Prior to the audit feedback, treatments were used often in some clinics, but only rarely in other clinics, for seemingly similar patients. During the feedback sessions three treatments were identified for more frequent use by several of the clinics: antidepressant and anticonvulsant drugs, and transcutaneous electrical nerve stimulation. Many changes in practice occurred after the audit intervention, with large increases in the utilisation of these three treatments. Since there is reasonable evidence to support the use of these treatments for chronic pain this represents an improvement in the process of care. The audit demonstrated that patient management can be improved by a combination of active feedback and discussions based around comparisons between centres.
Anaesthesia and the Internet
Authors: YENTIS S. M. , OOI R.
Published: February 2007

The Internet is a network of computers that allows rapid transfer of information throughout the world. The number of medical, and particularly anaesthetic, resources is rapidly increasing. This article briefly describes the Internet and its features which may be of interest to anaesthetists and intensivists in the United Kingdom, together with some of the tools for working with them.
Compartment syndrome with severe rhabdomyolysis in the postoperative period following major vascular surgery
Authors: Ferreira T. A. , Pensado A. , Dominguez L. , Aymerich H. , Molins N.
Published: February 2007

We report a case of compartment syndrome with marked rhabdomyolysis in the immediate postoperative period following major vascular surgery. Early and aggressive treatment, based on intravenous fluids, sodium bicarbonate, mannitol and fasciotomy, resulted in satisfactory management of the patient and prevented the onset of severe complications, such as acute renal failure in a patient who presented several factors that predisposed him to this disorder.