bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparison of the vasodilatation produced by two topical anaesthetics
Authors: Ashley E. M. C. , Quick D. G. C. , El‐Behesey B. , Bromley L. M.
Published: March 2003

The vasoactive properties of EMLA (eutectic mixture of local anaesthetic) and amethocaine were compared using Doppler colour ultrasound to measure vein diameter in 20 male volunteers. EMLA or amethocaine cream were applied over veins on the dorsum of the hand and vein diameter was measured prior to application of the preparations and at 1, 1.5 and 2 h after removal. Visual analogue scores for skin colour and vasodilatation were performed at 1 h. The results showed no significant difference in vein diameter between the EMLA and amethocaine groups. However, the amethocaine‐treated hands were significantly more erythematous at 1 h (p < 0.00002).
Effective time to satisfactory intubation conditions after administration of rocuronium in adultsComparison of propofol and thiopentone for rapid sequence induction of anaesthesia
Authors: Dobson A. P. , McCluskey A. , Meakin G. , Baker R. D.
Published: March 2003

We determined the effective time to satisfactory intubation conditions after the administration of rocuronium 0.6 mgkg−1 to 120 unpremedicated adult patients anaesthetised with propofol 2.5 mgkg−1 or thiopentone 5 mgkg−1. Intubation conditions were assessed in 10 subgroups of 12 patients at 30, 40, 50, 60 and 70 s. The effective times to satisfactory intubation conditions in 50 and 90% of patients were obtained by the method of maximum likelihood after log time–probit response transformations. Intubation conditions after induction of anaesthesia with propofol were satisfactory in 5/12 patients at 30 s, 7/12 at 40 s, 10/12 at 50 s, 11/12 at 60 s and 11/12 at 70 s compared with 1/12 patients at 30 s, 2/12 at 40 s, 5/12 at 50 s, 7/12 at 60 s and 8/12 at 70 s after induction with thiopentone. The effective times to satisfactory intubation conditions in 50% and 90% (95% confidence intervals) of patients after rocuronium 0.6 mgkg−1 were 34 (26–40) s and 61 (50–81) s in patients given propofol compared with 57 (48–69) s and 101 (79–167) s in patients given thiopentone. We conclude that rocuronium 0.6 mgkg−1 may be a suitable alternative to suxamethonium during rapid sequence induction of anaesthesia with propofol in situations where suxamethonium is contraindicated.
Radicular acute pain after epidural anaesthesia with the technique of loss of resistance with normal saline solution
Authors: Gracia J. , Gomar C. , Riambau V. , Cardenal C.
Published: March 2003

Epidural anaesthesia using the loss of resistance to saline technique, without air, was successfully performed in a 65‐year‐old man scheduled for elective vascular surgery of the right leg. Epidural catheterisation was uneventful. Fifteen minutes after the initial dose of plain 0.5% bupivacaine, the patient experienced severe pain in his lower abdomen and legs which coincided with a supplementary injection of 2 ml bupivacaine and 50 μg fentanyl, and a change from the lateral to the supine position. General anaesthesia was induced and CT and MRI scans were performed showing trapped air in the epidural space at the L4 level causing compression of the thecal sac. After excluding other causes, the spontaneous entry of air through the Tuohy needle was thought to be the most likely explanation for this complication. The patient recovered uneventfully.
Meeting the standards for interhospital transfer of adults with severe head injury in the United Kingdom
Authors: Knowles P. R. , Bryden D. C. , Kishen R. , Gwinnutt C. L.
Published: March 2003

In December 1996, the Association of Anaesthetists of Great Britain and Ireland produced a series of recommendations outlining the safe conduct of interhospital transfers for patients with acute head injuries. We assessed the current ability of UK hospitals to implement these recommendations and opinions on the formation of transfer teams, using a postal questionnaire. This was sent to all Royal College of Anaesthetists tutors, 268 of whom replied (94% response rate). Of the hospitals surveyed, 208 received adult head‐injury patients but did not have on‐site neurosurgical facilities. In 171 (86.8%) of these hospitals, senior house officers could be expected to accompany the patient during subsequent transfer. The majority of hospitals (192, 92.3%) were able to monitor ECG, pulse oximetry and blood pressure during the journey, but only 97 (46.6%) had facilities to monitor end tidal carbon dioxide levels. As a result of the anaesthetist‘s involvement in the transfer, emergency operating could be delayed in 169 (81.3%) hospitals. One hundred and fifty‐eight (76%) respondents thought that the formation of transfer teams to transport critically ill patients would have some merit. Hospitals are responding to the published guidelines, but improvements are still needed in levels of equipment and insurance provision, along with the identification of a designated consultant at each hospital with responsibility for transfers.
Comparison of sevoflurane and propofol with rocuronium for modified rapid‐sequence induction of anaesthesia
Authors: Lowry D. W. , Carroll M. T. , Mirakhur R. K. , Hayes A. , Hughes D. , O'Hare R.
Published: March 2003

We compared the use of sevoflurane and propofol with three different doses of rocuronium for modified rapid‐sequence induction of anaesthesia. One hundred and forty adult patients were randomly allocated to have a rapid‐sequence intravenous induction with propofol 2–3 mg.kg−1 (group P) or an inhalational induction with sevoflurane 8% in oxygen, using a vital capacity technique (group S). Following loss of the eyelash reflex, cricoid pressure was applied and 20 patients in each group were administered rocuronium 0.3 (groups P/0.3 and S/0.3), 0.45 (groups P/0.45 and S/0.45) or 0.6 (groups P/0.6 and S/0.6) mg.kg−1. An additional 10 patients in each group received only saline placebo in place of the muscle relaxant (groups P/Saline and S/Saline). Laryngoscopy was started 60 s later and intubating conditions evaluated by a blinded anaesthetist according to a standard scoring system. Intubating conditions were acceptable in one patient and no patient, respectively, following induction with sevoflurane and propofol without the muscle relaxant. The conditions were acceptable in 30, 55 and 90% of subjects with sevoflurane induction, and in 45, 80 and 90% of subjects with propofol induction following 0.3, 0.45 and 0.6 mg.kg−1 of rocuronium, respectively (no significant difference for each dose of rocuronium). The present study shows that intubating conditions during a rapid‐sequence induction using rocuronium 0.6 mg.kg−1 following induction of anaesthesia with sevoflurane or propofol are similar.
Decontamination of laryngoscopes: a survey of national practice
Authors: Esler M. D. , Baines L. C. , Wilkinson D. J. , Langford R. M.
Published: March 2003

We conducted a postal questionnaire to survey methods of laryngoscope cleaning in units throughout Great Britain. We found that there was great variation in practice. Most units autoclave laryngoscope blades at some time, but less than one‐quarter do so between each case. A wide range of methods is used to clean the blade in units where autoclaving was not undertaken. Most units had no guidelines relating to laryngoscope treatment between uses.
Postoperative sore throat: cause, prevention and treatment
Authors: McHardy F. E. , Chung F.
Published: March 2003

Sore throat is a common postoperative complaint, occurring most often following tracheal intubation. Factors such as tracheal‐tube size and cuff design have been shown to be important causative factors. Routine tracheal intubation for elective surgical procedures can result in pathological changes, trauma and nerve damage which may also account for postoperative throat symptoms. Sore throat following the use of a laryngeal mask appears to be related to the technique of insertion but the contribution of intracuff pressure remains to be clarified. It would appear, however, that high intracuff pressure is associated with nerve palsies due to neuropraxia and nerve compression. Careful insertion techniques for both the tracheal tube and laryngeal mask are of paramount importance in the prevention of airway trauma and postoperative sore throat.
ICU admission in patients infected with the human immunodeficiency virus — a multicentre survey
Authors: Gill J. K. , Greene L. , Miller R. , Pozniak A. , Cartledge J. , Fisher M. , Nelson M. R. , Soni N.
Published: March 2003

We conducted a retrospective study to assess the reasons for admission to the intensive care unit, and subsequent outcome, in patients infected with the human immunodeficiency virus (HIV). Four hospitals in the south of England participated, all with specialist HIV units. Data were collected on 127 patients admitted to ICU on 133 separate occasions between June 1993 and October 1997. The mean age on admission was 38 years (range 23–60 years). Ninety‐four patients (70.7%) were documented HIV‐positive before admission and 36 (27%) were diagnosed HIV‐positive for the first time during admission; 36.1% were admitted with Pneumocystis carinii pneumonia. Overall ICU mortality was 33%, in‐hospital mortality was 56% and the eventual mortality at the end of follow‐up (March 1998) was 72%. Survival was highest in those admitted with respiratory HIV‐related disease or HIV‐unrelated illness. Associations with poor outcome included a prior AIDS‐defining illness, a CD4 cell count of less than 100 cells.ml−1 and admission secondary to sepsis.
Effects of lamotrigine on pain‐induced chemo‐somatosensory evoked potentials
Authors: Klamt J. G. , Posner J.
Published: March 2003

Lamotrigine, a sodium channel blocker that selectively inhibits the neuronal release of glutamate, has been shown to produce analgesia in acute and chronic pain models in rats without causing noticeable sedation. After oral administration it also reduces pain scores, as assessed by the cold pain test, in volunteers. The purpose of this study was to determine the analgesic effect of lamotrigine given by mouth to healthy volunteers as evidenced by alterations in chemo‐somatosensory evoked potentials. The following factors were measured: latency to N1 and P100 peak (ms); amplitude between the N1 and P100 peak (μV); visual analogue pain intensity scores. A double‐blind, randomised and crossover design was used in which 12 volunteers received either placebo or lamotrigine 300 mg on separate occasions as determined by the randomisation schedule. Volunteers were tested before and 2 h after the treatment. The plasma lamotrigine concentration was measured immediately after the end of the experimental sessions. Lamotrigine produced a significantly higher latency to P100 values at 2 h postdrug than placebo (p < 0.05) but had no significant effects on the other factors. Although plasma concentrations were similar to those observed in the cold pain test, we conclude that lamotrigine 300 mg by mouth had no analgesic effect in this acute pain model.
Comparison of sevoflurane and total intravenous anaesthesia for daycase urological surgery
Authors: Fish W. H. , Hobbs A. J. , Daniels M. V.
Published: March 2003

Target‐controlled total intravenous anaesthesia using propofol and remifentanil was compared with inhalational anaesthesia using sevoflurane and alfentanil in patients undergoing daycase urological surgery. Seventy‐one patients were randomly allocated to receive either a target‐controlled infusion of an admixture of propofol and remifentanil (125 μg of remifentanil added to 500 mg of propofol), or inhalational anaesthesia with sevoflurane and intra‐operative alfentanil. There was no difference in time to fitness for discharge, time to fitness for transfer from primary to secondary recovery, time to first oral intake or adverse anaesthetic induction occurrences. Patient satisfaction assessed at 24 h post‐discharge was high in both groups with no significant difference between groups. The incidence of nausea and vomiting was low in both groups. We conclude that, for ultra‐short stay surgery, both the techniques we describe offer satisfactory anaesthesia with very early resumption of street fitness.
Ventilatory characteristics in mechanically ventilated patients during manual hyperventilation for chest physiotherapy
Authors: Clarke R. C. N. , Kelly B. E. , Convery P. N. , Fee J. P. H.
Published: March 2003

We measured the tidal volumes and peak inflation pressures generated during manual hyperventilation for chest physiotherapy in 25 adult ventilated patients. The average tidal volume ranged from 711 to 1511 ml, with a mean (SD) of 1120 (274) ml. There was a negative correlation (p < 0.05) between the average tidal volume and the lung injury, as measured by the Murray lung injury score. The average peak inflation pressure ranged from 37 to 74 cmH2O with a mean (SD) of 51.5 (7.6) cmH2O. There was a positive correlation (p < 0.05) between average peak inflation pressure and the lung injury score. Mean (SD) Pao2 improved by 18.3 (14.3) kPa from baseline after physiotherapy (p < 0.05). Mean (SD) Paco2 decreased by 0.1 (0.4) kPa. As the lung score increases higher inflation pressures and smaller tidal volumes are used suggesting an increased potential for barotrauma or volutrauma in susceptible lungs.
An epidural scoring scale for arm movements (ESSAM) in patients receiving high thoracic epidural analgesia for coronary artery bypass grafting
Authors: Abd Elrazek E. , Scott N. B. , Vohra A.
Published: March 2003

Thoracic epidural analgesia appears to improve the outcome of patients undergoing coronary artery bypass graft surgery. Cranial extension of nerve blockade involving the third, fourth and fifth cervical nerve roots can cause apnoea. However, progressive paraesthesia and weakness due to cephalad spread of thoracic epidural analgesia will affect the arms before the diaphragm. A scale was designed to test three active movements of the arms bilaterally: hand grip (T1/C8), wrist flexion (C8/7) and elbow flexion (C6/5). This epidural scoring scale for arm movements (ESSAM) consists of four grades (0–3) based on the number of absent movements, and suggests appropriate action. The reliability of this scale was tested in 40 patients undergoing coronary artery bypass surgery. Twelve of the 40 patients had their epidural infusion reduced on the basis of the scale. Of these 12 patients, eight had a worst ESSAM score of 1, three had a worst score of 2 and one had a worst score of 3. In each patient, motor power returned following the reduction in infusion rate, taking between 30 min and 3 h. This scale appears to be a simple and reliable method for the early detection of the cephalad spread of thoracic epidural analgesia.
Organophosphorus poisoning and anaesthesia
Authors: Karalliedde L.
Published: March 2003

Organophosphorus compounds, used as insecticides and agents of chemical warfare, are a major global cause of health problems. These irreversible inhibitors of cholinesterase produce three well‐recognised clinical entities: the initial cholinergic phase, which is a medical emergency often requiring management in an intensive care unit; the intermediate syndrome, during which prolonged ventilatory care is necessary; and delayed polyneuropathy. In addition, disturbances of body temperature and endocrine function, electrolyte imbalances, immunological dysfunction and disorders of reproduction have been reported in animals and man. Vocal cord paralysis, pancreatitis, cardiac arrhythmias and a wide range of neuropsychiatric disorders are known to follow acute and chronic exposure to organophosphorus compounds. As a result of the inhibition of plasma cholinesterase, there can be increased sensitivity to drugs hydrolysed by this enzyme, e.g. suxamethonium and mivacurium. The inhibition of acetylcholinesterase causes dysfunction at the neuromuscular junction which can produce altered responses to nondepolarising neuromuscular blockers. Anaesthetists may encounter patients exposed to organophosphorus compounds either following acute poisoning, trauma (warfare) or as patients with a wide range of nonspecific disorders presenting for surgery. The traditional use of oximes and atropine in treatment has failed to reduce the morbidity and mortality associated with poisoning. The roles of agents that have reduced the toxicity of organophosphorus compounds in animal experiments are discussed as potential therapeutic agents. There is an urgent need for accurate information on the problems associated with exposure to organophosphorus compounds. This would best be achieved by collaborative research between technologically advanced countries and developing countries, where organophosphorus compounds are a leading cause of ill health.
The contamination of volatile anaesthetics in an in‐circle vaporiser with water during prolonged closed‐circle anaesthesia
Authors: Harrison G. R.
Published: March 2003

The amount of water present in sevoflurane in an in‐circle vaporiser after long procedures was measured. This demonstrated that the sevoflurane residue was contaminated with a small amount of water.
Peripartum general anasthesia without tracheal intubation: incidence of aspiration pneumonia
Authors: Ezri T. , Szmuk P. , Stein A. , Konichezky S. , Hagai T. , Geva D.
Published: March 2003

This study estimated the incidence of pulmonary aspiration during general anasthesia for obstetric procedures performed in the peripartum period (Caesarean sections were not studied). The records of 1870 patients anasthetised without tracheal intubation were reviewed retrospectively. The diagnosis of aspiration was based on the anasthetist's written remarks and the postoperative course. Eighty per cent of patients received ketamine and a benzodiazepine, and the remaining 20% received methohexital or thiopental and fentanyl. No cricoid pressure or tracheal intubation was performed. A single case of mild aspiration was detected in a woman anasthetised with methohexital (an incidence of 0.053%). These results suggest that the risk of aspiration during general anasthesia without tracheal intubation, during and immediately after delivery, may not be higher in obstetric patients in the peripartum period, as has been reported previously.
Chemical stability of bupivacaine, lidocaine and epinephrine in pH‐adjusted solutions
Authors: Robinson J. , Fernando R. , Sun Wai W. Y. S. , Reynolds F.
Published: March 2003

Epinephrine and sodium bicarbonate may be added to local anaesthetic solutions in order to reduce the onset time and enhance the quality of epidural anaesthesia for Caesarean section. Such mixtures are sometimes prepared several hours in advance for subsequent use in emergency Caesarean section through a pre‐existing epidural catheter. To evaluate this practice, we studied the chemical stability in solution over 24 h of nine epidural mixtures consisting of different combinations of bupivacaine, lidocaine, epinephrine and sodium bicarbonate. In mixtures alkalinised with sodium bicarbonate, epinephrine concentrations decreased significantly over 24 h (p < 0.0001), whereas those in nonalkalinised mixtures did not change with time. Bupivacaine and lidocaine concentrations in all mixtures did not decrease over time regardless of alkalinisation. We do not recommend adding epinephrine to alkalinised epidural solutions that are to be stored for a prolonged period before clinical use.
The effect of smoking on postoperative nausea and vomiting
Authors: Chimbira W. , Sweeney B. P.
Published: March 2003

In an attempt to quantify the postoperative effects of smoking, 327 consecutive patients undergoing arthroscopic day case knee surgery were given a standard anaesthetic consisting of an intravenous induction with propofol and fentanyl followed by inhalational maintenance using isoflurane in an oxygen and nitrous oxide mixture. Pre‐operatively, patients were asked inter alia to give details of social smoking habits. Postoperatively, patients were given standard analgesic and anti‐emetic drugs. Prior to discharge patients were asked to give details of postoperative nausea and vomiting together with details of the severity of postoperative pain. There were 85 smokers and 242 nonsmokers. Of the 327 patients, a total of 42 (13%) complained of postoperative nausea and vomiting. Of the smokers, only 6% complained of postoperative nausea and vomiting in contrast to 15% of the nonsmokers (p < 0.05). It is postulated that enzyme induction is the most likely reason for this anti‐emetic effect. Possible ways in which this clinically beneficial mechanism can be utilised to improve outcome after anaesthesia are discussed.
Closed loop control of anaesthesia: an assessment of the bispectral index as the target of control
Authors: Morley A. , Derrick J. , Mainland P. , Lee B. B. , Short T. G.
Published: March 2003

We investigated the performance of a closed‐loop system for administration of general anaesthesia, using the bispectral index as a target for control. One hundred patients undergoing gynaecological or general surgery were studied. In 60 patients, anaesthesia was maintained by intravenous infusion of a propofol/alfentanil mixture. In 40, an isoflurane/nitrous oxide based technique was used. For each technique, patients were randomly allocated to receive either closed‐loop or manually controlled administration of the relevant agents (propofol/alfentanil or isoflurane), with an intra‐operative target bispectral index of 50 in all cases. Closed‐loop and manually controlled administration of anaesthesia resulted in similar intra‐operative conditions and initial recovery characteristics. During maintenance of anaesthesia, cardiovascular and electro‐encephalographic variables did not differ between closed‐loop and manual control groups and deviation of bispectral index from the target value was similar. Intra‐operative concentrations of propofol, alfentanil and isoflurane were within normal clinical ranges. Episodes of light anaesthesia were more common in the closed‐loop group for patients receiving propofol/alfentanil anaesthesia and in the manual group for patients receiving isoflurane/nitrous oxide anaesthesia. Convenience aside, the closed‐loop system showed no clinical advantage over conventional, manually adjusted techniques of anaesthetic administration.
Learning fibreoptic endoscopy
Authors: Smith J. E. , Jackson A. P. F.
Published: March 2003

We have studied the extent to which learning fibreoptic nasotracheal endoscopy first helped anaesthetists to learn fibreoptic orotracheal endoscopy later, and vice versa. After preliminary training on a bronchial tree model, 30 anaesthetic trainees were randomly allocated to the nasal first/oral second group, who performed 10 nasal intubations followed by 10 oral intubations, or the oral first/nasal second group, who performed 10 oral intubations followed by 10 nasal intubations, in anaesthetised, ASA group I or II patients undergoing elective oral or general surgery. Each type of endoscopy was taught in a standard manner, with the aid of an endoscopic video‐camera system, under the supervision of experienced instructors. Performing nasal endoscopy second (average 70.8 s) took significantly less time than performing it first (average 84.4 s) and performing oral endoscopy second (average 35.2 s) took significantly less time than performing it first (average 48.5 s). The mean (SD) total endoscopy time for all the endoscopies (both nasal and oral) in the nasal first/oral second group [1196 (162) s] was not significantly different from that for all the endoscopies in the oral first/nasal second group [1193 (188) s]. Because there is no advantage or disadvantage to be gained in starting to learn either type of endoscopy first, graduated training programmes can be planned according to the availability of suitable patients for fibreoptic intubation, without instructors needing to consider whether trainees make better progress if they learn one technique before the other.
Survival from a lethal blood concentration of cyanide with associated alcohol intoxication
Authors: Kampe S. , Iffland R. , Korenkov M. , Diefenbach CH.
Published: March 2003

We present a patient with a lethal blood concentration of cyanide. Additionally, he was found to have an alcohol blood level of 270 mg.dl−1, but made a complete recovery following administration of the antidotes dimethylaminophenol and thiosulphate. It is postulated that the patient may have been able to detoxify himself as a result of metabolism of cyanide to the non‐toxic form, thiocyanate.
Substance misuse amongst anaesthetists in the United Kingdom and Ireland
Authors: Berry C. B. , Crome I. B. , Plant M. , Plant M.
Published: March 2003

Three hundred and four departments of anaesthesia in UK and Ireland were sent questionnaires about alcohol and drug abuse in anaesthetists over the preceding 10‐year period. Information was sought on the nature and extent of substance problems, their presentation and management. The survey achieved a high response rate of 71.7% and a total of 130 cases were reported, of whom 34.6% were consultants and 43.2% were trainees. Over 50% of respondents felt a lack of confidence in dealing with alcohol or drug misuse amongst colleagues. The results of this survey demonstrate that over one anaesthetist per month has presented with significant alcohol or drug misuse in the UK and Ireland over the last 10 years. It is important that those with management responsibilities for departments of anaesthesia are aware that such problems exist and are likely to impact on the professional ability and health of the affected individual. The Working Party on Substance Abuse at the Association of Anaesthetists has recently published guidance in the management of these problems. A case is made for increasing awareness in this sensitive subject to enable early recognition and treatment of an anaesthetist who is misusing alcohol and drugs since intervention can be effective.
Percutaneous tracheostomy by forceps dilation: report of 162 cases
Authors: Escarment J. , Suppini A. , Sallaberry M. , Kaiser E. , Cantais E. , Palmier B. , Quinot J. F.
Published: March 2003

A prospective, observational clinical study evaluated the safety of percutaneous single‐step dilational tracheostomy over a 43‐month period. One hundred and sixty‐two patients were deemed suitable for the procedure. The mean duration of tracheal intubation prior to tracheostomy was 6 days. The mean duration of the procedure was 9.3 min. Intra‐operative complications occurred in 27 patients (16.6%), most of which were minor technical difficulties without morbidity. Postoperative complications, some of which were associated with morbidity, occurred in 16 patients. There were two deaths secondary to premature decannulation, one case of severe bleeding and five pneumothoraces. Long‐term complications were assessed in 81 patients; there were four tracheal stenoses requiring surgery or laser therapy and seven patients with granulation tissue at the stoma site which did not require treatment. Forceps dilatational percutaneous tracheostomy appeared to be a convenient bedside procedure. However, complications do occur and further studies should address late sequellae, such as tracheal stenosis.
Anaesthetic management of a patient with pemphigus vulgaris for emergency laparotomy
Authors: Mahalingam T. G. , Kathirvel S. , Sodhi P.
Published: March 2003

A 45‐year‐old man with a long‐standing history of duodenal ulcer presented with symptoms and signs of perforation peritonitis. He also had lesions of pemphigus vulgaris throughout the body, involving both skin and mucous membranes. Care was taken to avoid pressure and friction during placement of monitoring devices, intravenous and arterial lines. Since the patient had to undergo exploratory laparotomy, intubation was performed in an atraumatic manner after rapid sequence induction. However, there was minor bleeding from the mucous lesions of the oral cavity, which was controlled by a saline adrenaline throat pack. The patient was extubated at the end of the surgery and steroids were continued in the peri‐operative period.
The effect of facial hair and sex on the dispersal of bacteria below a masked subject
Authors: McLure H. A. , Mannam M. , Talboys C. A. , Azadian B. S. , Yentis S. M.
Published: March 2003

Surgical face masks prevent the dispersal of bacteria from the upper airway to surfaces immediately in front of and below the face during talking. However, mask wiggling has been reported to increase dermabrasion and bacterial contamination of surfaces immediately below the face. Facial hair and recent shaving may alter the quantity of particles shed by dermabrasion when the mask is wiggled. We investigated the effect of mask wiggling in 10 bearded and 10 clean‐shaven male subjects, and 10 female subjects. Wiggling the mask significantly increased the degree of bacterial shedding onto agar plates 15 cm below the lips in bearded males (p = 0.03) and females (p = 0.03), but not in clean‐shaven males. At rest without mask wiggling the bearded subjects shed significantly more bacteria than clean‐shaven males (p = 0.01) or females (p = 0.001). To reduce the risks of contamination of the sterile field when face masks are worn females and bearded males should avoid wiggling the face mask. Bearded males may also consider removing their beards.
Desflurane or sevoflurane for gynaecological day‐case anaesthesia with spontaneous respiration?
Authors: Mahmoud N. A. , Rose D. J. A. , Laurence A. S.
Published: March 2003

Sixty gynaecological day‐case patients were anaesthetised with either desflurane or sevoflurane in oxygen/nitrous oxide, following intravenous induction. Mean end‐tidal desflurane was 4.5% at 5 and 10 min post induction, whereas mean end‐tidal sevoflurane was 1.7%. There were five untoward airway events (coughing, hiccoughs) in the desflurane group and three in the sevoflurane group, including one laryngospasm. Time to eye opening and orientation following anaesthesia were significantly faster in the desflurane group (2.8 min/4.8 min) than in the sevoflurane group (7.0 min/9.8 min; p < 0.0001). Time to being ready for discharge home was also significantly earlier in the desflurane group (3 h compared with 3.5 h). Telephone interview on the first postoperative day showed that in the desflurane group 29 of 31 were fully returned to normal activity compared with only 15 out of 29 in the sevoflurane group (p < 0.01).
Comparison of sevoflurane–nitrous oxide anaesthesia with the conventional intravenous–inhalational technique using bispectral index monitoring
Authors: Shah M. K. , Tan H. M. , Wong K.
Published: March 2003

Ninety‐one patients were randomly allocated to one of two groups. Group A was induced with a single vital capacity breath of 6% (end‐tidal) sevoflurane in nitrous oxide–oxygen (2 : 1 l.min−1), whereas group B was induced with intravenous fentanyl 1 µg.kg−1+ propofol 2 mg.kg−1 followed by nitrous oxide–oxygen (2 : 1 l.min−1) and sevoflurane. Induction was considered to have been achieved when the bispectral index value decreased to below 70. Mean induction time in group A (95.2 s, 95% CI 88.5–101.9 s) was longer than group B (70.3 s, 95% CI 66.3–74.3 s; p < 0.0001). Mild coughing was more common in group A, but relative hypotension was more common in group B. There was no difference in the emergence times. Thirty minutes after emergence, there was no difference in the incidence of adverse effects, with the exception of essentially mild abdominal pain which was more frequent in group A.
An assessment of a method of inflating cuffs with a nitrous oxide gas mixture to prevent an increase in intracuff pressure in five different tracheal tube designs
Authors: Karasawa F. , Tokunaga M. , Aramaki Y. , Shizukuishi M. , Satoh T.
Published: March 2003

We assessed the efficacy of inflating cuffs with a nitrous oxide gas mixture to minimise changes in intracuff pressure during anaesthesia. Patients were randomly assigned to one of five groups of 15 subjects each, and the trachea was intubated with the Profile Soft‐Seal Cuff, Hi‐Contour, Reinforced, Sheridan or Trachelon tracheal tubes. Cuffs were inflated with 40% nitrous oxide and cuff pressure was measured during anaesthesia with 67% nitrous oxide. Concentration of nitrous oxide in the cuff was measured at the end of anaesthesia. Cuff pressure increased slightly but significantly in the Reinforced and Trachelon groups. Nitrous oxide concentration in the Reinforced, Sheridan, or Trachelon groups was slightly but significantly higher than that in the Profile or Hi‐Contour groups. Cuff pressure never exceeded 22 mmHg and there were no air leaks. Therefore, inflating cuffs with 40% N2O preserves stable cuff pressure in all five tracheal tubes, despite differences in cuff and pilot balloon design.
Epidural ropivacaine hydrochloride during labour: protein binding, placental transfer and neonatal outcome
Authors: Porter J. M. , Kelleher N. , Flynn R. , Shorten G. D.
Published: March 2003

This study was undertaken: (i) to quantify the effects of labour and epidural analgesia on plasma α1‐acid glycoprotein concentration, (ii) to examine the effects of changes in plasma α1‐acid glycoprotein concentration on plasma protein binding and placental transfer of ropivacaine, and (iii) to examine the association between umbilical venous ropivacaine concentration and neurobehavioural function in the neonate. Multiparous patients undergoing induction of labour received a continuous epidural infusion of 0.1% ropivacaine following an epidural bolus. A significant association was demonstrated between maternal plasma α1‐acid glycoprotein concentration and 1/free fraction of ropivacaine 60 min after starting ropivacaine administration (r2 = 0.77) but not at delivery. No significant correlation was demonstrable between maternal unbound ropivacaine concentration and either neonatal (cord) ropivacaine concentration or UV/MV (a measure of placental transfer). Thirty minutes after delivery, 9/10 neonates had neurological and adaptive capacity scores < 35, whereas only three infants had scores < 35 at 2 h. All scores exceeded 35 16 h after delivery. No association between mean (SD) umbilical venous ropivacaine concentration [0.09 (0.08) mg.l−1] and neurological and adaptive capacity scores was demonstrated.
Indices of nitric oxide synthesis and outcome in critically ill patients
Authors: Mackenzie I. M. , Garrard C. S. , Young J. D.
Published: March 2003

We measured the concentrations of serum nitrates/nitrites and plasma cyclic guanosine monophosphate as markers of nitric oxide synthesis in patients with or without septic shock for 5 days following admission to intensive care. We found that nitrate/nitrite concentrations, when corrected for the effect of renal failure, were significantly higher in patients with septic shock, both on admission and in the final samples drawn. In a logistic regression analysis, the rate of change of nitrate/nitrite concentration was associated with survival to day 28 (falling in survivors). The concentration of cyclic guanosine monophosphate when corrected for the confounding effects of renal function and platelet count, was only associated with the septic shock group on admission.
Postoperative residual block after intermediate‐acting neuromuscular blocking drugs
Authors: Hayes A H. , Mirakhur R. K. , Breslin D. S. , Reid J. E. , McCourt K. C.
Published: March 2003

The frequency and duration of postoperative residual neuromuscular block on arrival of 150 patients in the recovery ward following the use of vecuronium (n = 50), atracurium (n = 50) and rocuronium (n = 50) were recorded. Residual block was defined as a train‐of‐four ratio of <0.8. An additional group of 10 patients received no neuromuscular blocking drugs during anaesthesia. The incidence of postoperative residual neuromuscular block was 64%, 52% and 39% after the use of vecuronium, atracurium and rocuronium, respectively. Similar numbers of patients were not able to maintain a sustained head or leg lift for 5 s on arrival in the recovery ward. The mean [range] times to attaining a train‐of‐four ratio of ≥0.8 after arrival in the recovery ward were 9.2 [1–61], 6.9 [1–24] and 14.7 [1.5–83] min for vecuronium, atracurium and rocuronium, respectively. None of the 10 patients who did not receive neuromuscular blocking drugs had train‐of‐four ratios <0.8 on arrival in the recovery ward. It is concluded that a large proportion of patients arrive in the recovery ward with a train‐of‐four ratio <0.8, even with the use of intermediate‐acting neuromuscular blocking drugs. Although the residual block is relatively short lasting, it may occasionally be prolonged, requiring close observation and monitoring of such patients in the recovery ward.
The in vitro performance of carbon dioxide absorbents with and without strong alkali
Authors: Bedi A. , Gallagher A. C. , Fee J. P. H. , Murray J. M.
Published: March 2003

We report the in vitro longevity of a conventional soda lime carbon dioxide absorbent and an absorbent free from strong alkali (Amsorb™). Although the times taken to breakthrough of carbon dioxide (> 0.5%) within an in vitro low flow breathing systern were shorter with the alkali‐free absorbent, we found that the size and shape of the absorbent container was the major factor in determining the efficiency of the carbon dioxide absorbents.
Extracting arterial flow waveforms from pulse oximeter waveforms
Authors: Cook L. B.
Published: March 2003

A method is described which allows an approximation to the arterial flow waveform to be derived from a pulse oximeter waveform. The observed pulse oximeter waveform is the sum of arterial inflow and venous outflow. These components are separated mathematically. Subtraction of the venous outflow reveals the underlying arterial flow waveform. The assumptions on which the method is based are stated explicitly and discussed.
Point‐of‐care testing
Authors: Hirsch J. , Wendt T. , Kuhly P. , Schaffartzik W.
Published: March 2003

Point‐of‐care testing of coagulation parameters provides a more rapid assessment of test results compared with laboratory testing. A new coagulation monitor (GEM® PCL, Instrumentation Laboratory, Kirchheim, Germany) was evaluated. Point‐of‐care data for activated partial thromboplastin time and prothrombin time (expressed as the international normalised ratio) and turn‐around‐time were compared. Coagulation parameters were compared in the blood of 57 patients with and without heparin therapy. The point‐of‐care and laboratory test results showed a bias (SD) of − 0.26 (4.55) s for activated partial thromboplastin time and − 0.011 (0.150) s for prothrombin time. The average turn‐around‐time was 3 min for point‐of‐care testing vs. 52 min for laboratory testing. We conclude that the reliability of point‐of‐care testing is sufficient for clinical use.
Exploration of xenon as a potential cardiostable sedative: a comparison with propofol after cardiac surgery
Authors: Dingley J. , King R. , Hughes L. , Terblanche C. , Mahon S. , Hepp M. , Youhana A. , Watkins A.
Published: March 2003

Xenon anaesthesia is thought to have minimal haemodynamic side‐effects. It is, however, expensive and requires special delivery systems for economic use. In this randomised cross‐over study, we: (i) investigated the haemodynamic profile and recovery characteristics of xenon compared with propofol sedation in postoperative cardiac surgery patients, and (ii) evaluated a fully closed breathing system to minimise xenon consumption. We demonstrated a significantly faster recovery from xenon (3 min 11 s) than propofol sedation (25 min 23 s). Relative to propofol, xenon sedation produced no change in heart rate or mean arterial pressure and there were significantly higher mean values for central venous pressure (10.6 vs. 8.9 mmHg), pulmonary artery occlusion pressure (11.2 vs. 9.5 mmHg), mean pulmonary artery pressure (20.1 vs. 18.3 mmHg) and systemic vascular resistance index (2170 vs. 1896 dyn.s.cm−5.m−2). The haemodynamic profile seen with propofol reflected its known vasodilator effects. This was supported by the almost identical left ventricular stroke work indexes seen with both methods of sedation.
Maternal anti‐factor Xa activity following subcutaneous unfractionated heparin after Caesarean section*
Authors: Stirrup C. A. , Lucas D. N. , Cox M. L. , Rucklidge M. , Nel M. R. , Acton L. J. , Costello C. , Yentis S. M.
Published: March 2003

Unfractionated heparin is widely used for prophylaxis against venous thromboembolism after Caesarean section. We performed a survey of thromboprophylactic methods after elective Caesarean section in 50 maternity units in the United Kingdom. We found that a variety of regimens were used. Thirteen (26%) used subcutaneous unfractionated heparin at standard (non‐pregnant) doses. We then studied anti‐Xa activity in women following elective Caesarean section under regional anaesthesia. Initially, eight women were given 5000 U unfractionated heparin subcutaneously after surgery and anti‐Xa activity was measured 1, 2, 3, 4, 5, 6, 8 and 10 h after administration. There was no detectable anti‐Xa activity in any of the samples so the dose was increased to 7500 U in a further five women and a single anti‐Xa assay performed at 3 h when peak activity should occur. Again, no activity was detected so the dose was increased to 10 000 U heparin in a final group of 10 women and anti‐Xa activity measured at 0.5, 1, 1.5, 2, 3, 4, 5 and 6 h. Although there was some activity after 10 000 U heparin, the level was below that accepted for prophylaxis. If anti‐Xa activity is an appropriate monitor of prophylactic unfractionated heparin, doses up to 10 000 U are inadequate. Since there is evidence that enoxaparin is effective at producing adequate prophylactic anti‐Xa activity following Caesarean section, we suggest abandoning the use of unfractionated heparin in favour of enoxaparin for this purpose.
Pressure in the cuffs of tracheal tubes at altitude
Authors: Smith R. P. R. , McArdle B. H.
Published: March 2003

SummaryPressures in the cuffs of three commonly used tracheal tubes (Portex Profile Softseal®, Mallinckrodt Lo‐Contour® and Mallinckrodt Hi‐Contour®, size 8.0 mm and 9.0 mm internal diameter), inflated with air, were measured during simulated ascents in an altitude chamber to 10 000 ft. There was no detectable difference in performance between sizes for each type of tracheal tube. When averaged over the two sizes for each type of tube, cuff pressure reached the␣critical perfusion pressure 50 cmH2O (37 mmHg) for tracheal mucosa at a higher altitude in the Portex Profile Softseal (2837 ft, 95% CI 2488–3186 ft) than in the Mallinckrodt Lo‐Contour (2128 ft, 95% CI 1779–2476 ft; p = 0.02) and Mallinckrodt Hi‐Contour (1820 ft; 95% CI 1471–2168 ft; p = 0.002) tracheal tubes. When the cuffs of the 9.0‐mm tracheal tubes were inflated with saline, much smaller increases in pressure were measured with increasing altitude, although inflation of the cuffs with saline was technically difficult. Commonly used tracheal tubes with air‐inflated cuffs can be used for aeromedical retrieval, but air should be evacuated from the cuffs after increases in altitude of as little as 2000–3000 ft.
Comparison of external jugular and central venous pressures in mechanically ventilated patients
Authors: Parker J. L. , Flucker C. J. R. , Harvey N. , Maguire A. M. , Russell W. C. , Thompson J. P.
Published: March 2003

Summary We compared central venous pressures, measured via a 150 mm triple lumen catheter in the internal jugular vein with simultaneous external jugular venous pressures, measured with a 5 mm cannula in the external jugular vein, in 24 patients undergoing major surgery. Patients were mechanically ventilated in the supine position. Six sets of paired measurements of mean central venous pressure and mean external jugular venous pressure were taken by a blinded observer, in random order and at end‐expiration at 30‐min intervals during surgery. Four patients were not studied because of a failure to cannulate the external jugular vein. The remaining 20 patients yielded 111 sets of paired measurements. The mean difference between external jugular venous pressure and central venous pressure was 0.3 mmHg over a range of central venous pressure of 0–22 mmHg. Limits of agreement were −3.6 to +3.0 mmHg (95% CI −4.1 to +3.5 mmHg). We conclude that external jugular venous pressure is an accurate estimate of central venous pressure in surgical patients undergoing mechanical ventilation.
Partner anxiety prior to elective Caesarean section under regional anaesthesia
Authors: Taylor I. R. , Bullough A. S. , Van Hamel J. C. M. , Campbell D. N. C.
Published: March 2003

Summary This study was designed to measure anxiety levels in 91 partners of women undergoing elective Caesarean section under regional anaesthesia and to outline potential relieving factors. Twenty‐eight per cent of partners were pathologically anxious. There was a positive association between anxiety and prior attendance at the anaesthetic assessment clinic (p = 0.008). There was no statistically significant association between anxiety and education, occupation, gender, relationship to the patient or previous attendance at Caesarean section. Concern about a safe outcome for the mother and child caused most anxiety, less being expressed regarding presence in the operating theatre or anaesthesia per se. Over 70% of partners expressed the view that attendance at the anaesthetic assessment clinic or provision of written information would reduce their anxiety.
Body computed tomography in critically ill patients
Authors: Kumta N. D. , Park G. , Toms A. , Housden B. , Dixon A. K.
Published: March 2003

Summary The aim of the study was to assess the effectiveness of computed tomography in the management of critically ill patients. We performed a prospective study over a 4‐month period. The requesting clinician was asked to document their clinical diagnosis and confidence thereof on a visual analogue scale. They were also asked about their management plan if computed tomography had not been available. After imaging, any change in the management plan was assessed. During the study period, 16 computed tomograms were performed on 14 patients. There were 21 possible clinical diagnoses: of these eight were confirmed, and 13 were refuted. Seven new diagnoses were established. Computed tomography did not help in the management of two patients and it led to more confusion in the management of one patient. The management of seven patients was altered after computed tomography and in six the management depended solely on computed tomography findings.
Effects of low‐dose alfentanil administration on central respiratory drive and respiratory pattern in spontaneously breathing ASA 1 patients
Authors: Conti G. , Pierdominici S. , Ferro G. , Bocci M. G. , Antonelli M. , Proietti R.
Published: March 2003

Summary The aim of this study was to assess the short‐term effects of the administration of low doses of alfentanil on respiratory drive and respiratory pattern. We studied 17 ASA I patients scheduled for minor surgery or endoscopic procedures. During spontaneous ventilation, Respiratory Rate, Tidal Volume, Total Respiratory Cycle, Inspiratory and Expiratory Time, Mean Inspiratory Flow, P0.1, Sao2 and Etco2 were all measured. The inspired oxygen concentration was 21% and measurements were made at baseline, 5 min (T1), 10 min (T2) and 15 min (T3) following an intravenous bolus injection 10 µg.kg−1 alfentanil. The administration of alfentanil produced a significant (p < 0.05) reduction in Sao2, minute volume and P0.1. In ASA I spontaneously breathing patients, the pre‐operative administration of low doses of alfentanil can initially reduce the respiratory centre activity leading to a reduction in minute volume and Sao2. We therefore recommend careful monitoring of cardio‐respiratory function in ASA I patients, following the administration of alfentanil.