bluuebunny/crossref_metadata_2025 huggingface dataset:
Prophylactic amrinone for weaning from cardiopulmonary bypass*
Authors: Lewis K. P. , Appadurai I. R. , Pierce E. T. , Halpern E. F. , Bode R. H.
Published: March 2003

This prospective, randomised, double‐blind, controlled clinical study was performed at a single tertiary referral centre to test the hypothesis that the prophylactic administration of amrinone before separation of a patient from cardiopulmonary bypass decreases the incidence of failure to wean, and to identify those patients who could be predicted to benefit from such pre‐emptive management. Two hundred and thirty‐four patients, scheduled to undergo elective cardiac surgery, were randomly allocated to receive either a bolus dose of 1.5 mg.kg−1 amrinone over 15 min, followed by an infusion of 10 µg.kg−1.min−1, or a bolus of placebo of equal volume followed by an infusion of placebo. Treatment with amrinone or placebo was initiated upon release of the aortic cross‐clamp, before weaning from cardiopulmonary bypass. Anaesthetic technique, monitoring and myocardial preservation methods were standardised for both groups. Significantly fewer patients failed to wean in the group that received prophylactic amrinone than in the control group (7 vs. 21%, p = 0.002). Amrinone improved weaning success regardless of left ventricular ejection fraction, although this benefit was statistically significant only in the group with left ventricular ejection fractions > 55%. Of the 32 patients who failed to wean from cardiopulmonary bypass, 14 had normal pre‐operative left ventricular ejection fractions.
Translaryngeal tracheostomy in highly unstable patients
Authors: Byhahn C. , Lischke V. , Westphal K.
Published: March 2003

Percutaneous tracheostomy is a widely accepted and commonly performed technique for attaining long‐term airway access in critically ill patients. However, severe respiratory failure and coagulopathy are relative contraindications for these procedures. We describe two patients with severe respiratory failure and inhibitor‐complicated haemophilia A who underwent elective percutaneous tracheostomy performed translaryngeally, using the new Fantoni technique. Apart from two minor bleeding episodes in the haemophilic patient which were controlled promptly, no other complications occurred. If certain precautions are observed carefully, we believe that translaryngeal tracheostomy is a procedure which is superior to other percutaneous techniques and safe even in patients with severe respiratory failure and coagulopathy.
Induction characteristics with 3% and 8% sevoflurane in adults: an evaluation of the second stage of anaesthesia and its haemodynamic consequences
Authors: Hall J. E. , Ebert T. J. , Harmer M.
Published: March 2003

The second stage of anaesthesia was examined during 3 and 8% sevoflurane induction to see if any shortening of its duration was at the expense of cardiovascular stability. Fourteen volunteers underwent consecutive, randomly ordered inductions. Pupil size, skin sympathetic activity, plasma catecholamines, blood pressure and heart rate were measured. Eight per cent sevoflurane produced significantly shorter times to loss of consciousness (mean 68 s (SD 18) vs. mean 150 s (SD38)) and durations of second stage (mean 58 s (SD 38) vs. mean 91 s (SD 46)). Blood pressure, heart rate and sympathetic nerve responses were the same in both groups. Compared with baseline, skin sympathetic activity was greatest during pre‐oxygenation (not significant) and unaltered during second stage. Both groups showed significantly increased plasma norepinephrine and heart rate and decreased blood pressure from baseline. Eight per cent sevoflurane induction produced a shorter second stage than 3% with equal cardiovascular stability and the same sympathetic response.
Comparison of recovery following rapacuronium, with and without neostigmine, and succinylcholine
Authors: Hayes A. , Breslin D. , Reid J. , Mirakhur R. K.
Published: March 2003

The neuromuscular blocking effects of a single dose of rapacuronium 1.5 mg.kg−1 with or without reversal with neostigmine have been examined in the present study and compared with a dose of succinylcholine 1.0 mg.kg−1. Neuromuscular block was measured mechanomyographically using train‐of‐four stimulation. Complete block occurred within 1 min with both agents. Twenty‐five per cent recovery of the first response of the train‐of‐four occurred in a median [range] time of 7.6 [5.7–11.3] min in the succinylcholine group and in 14.2 [8.8–23.6] and 15.1 [9.6–23.4] min in the rapacuronium groups with and without neostigmine reversal, respectively. Spontaneous recovery to a train‐of‐four ratio of 0.8 took 33.4 [20.0–79.0] min with rapacuronium but this was reduced to about 21.2 [13.9–33.7] min when neostigmine was administered at 25% recovery of first twitch of the train‐of‐four.
Reserve nitrous oxide cylinders on anaesthetic machines
Authors: Rousseau G. F. , Carr A. S.
Published: March 2003

The presence of reserve nitrous oxide cylinders on anaesthetic machines is not necessary and potentially hazardous, wasteful and polluting. Although reserve nitrous oxide cylinders are routinely present on the anaesthetic machines in many hospitals in the UK, it is our concern that they are not checked or maintained properly. We examined a sample of cylinders and surveyed the practice amongst the anaesthetic staff in our Department with an anonymous questionnaire. This confirmed that: (1) the equipment is not properly maintained, 68% of cylinders sampled having passed a 3‐year expiry date; (2) checks are of little practical use, are not routinely performed by anaesthetists, and only 46% of respondents routinely check the nitrous oxide cylinders. In conclusion, the nitrous oxide cylinders are not properly checked or maintained and may represent a safety hazard.
The effects of syringe plunger design on drug delivery during vertical displacement of syringe pumps
Authors: Weiss M. , Fischer J. , Neff T. , Baenziger O.
Published: March 2003

Fluid delivery from four types of commercially available 50‐ml syringes was measured using an electronic balance at an infusion rate of 1 ml.h−1. Retrograde aspiration volume and zero‐drug delivery time were recorded after lowering the syringe pump by 50 cm. Syringe compliance was calculated from the volume of bolus released after occlusion at 100 mmHg. Zero‐drug delivery times differed significantly between syringes, ranging from [mean (SD)] 3.26 (0.40) min to 6.38 (0.56) min (F = 55.5, d.f. = 3/20, p < 0.0001). Syringe compliance correlated well with aspiration volume (Pearson r2 = 0.92, p < 0.001) and zero‐drug delivery time (r2 = 0.90, p < 0.001). Syringe design affected the internal syringe compliance. All syringes were associated with potentially relevant zero‐drug delivery times after moderate vertical displacement. To minimise this risk, vertical displacement of syringe pumps delivering highly vasoactive drugs should be avoided.
Lingual thyroid – a threat to the airway
Authors: Buckland R. W. , Pedley J.
Published: March 2003

The occurrence of a thyroid gland superficially placed on the pharyngeal portion of the tongue is rare, but poses problems to the patient and anaesthetist. This report describes a patient with a lingual thyroid and a history of problems associated with it that resulted in admission to the ICU and warnings about future intubation of the larynx. The patient underwent awake tracheal intubation using a standard fibreoptic assisted technique, and was advised that she purchase an appropriate Medic‐Alert bracelet.
Evaluation of a pilot regimen for postoperative pain control in patients receiving oral morphine pre‐operatively
Authors: Peacock J. E. , Wright B. M. , Withers M. R. , Luntley J. B. , Atkinson R. E.
Published: March 2003

Postoperative analgesia in patients who receive regular oral opioids pre‐operatively is frequently suboptimal. To improve management we introduced a regimen using subcutaneous diamorphine infusions with incremental doses. Infusion doses were calculated as half the daily pre‐operative dose of oral morphine with the increments as one‐sixth of the infusion dose. Results were recorded on the first two postoperative days before (n = 13) and after (n = 23) commencing the new regimen. The percentage of patients reporting severe pain at rest and on movement were significantly reduced by the new regimen (54% and 69% vs. 13% and 40%, respectively) since the opioid dose as a percentage of the pre‐operative dose was significantly higher (160% vs. 352%). There were no instances of excessive sedation or slow respiratory rate in any patient. The use of the regimen has resulted in greater doses of opioids being administered with fewer patients in severe pain without significant complications.
The effect of the addition of ropivacaine or bupivacaine upon pruritus induced by intrathecal fentanyl in labour
Authors: Shah M. K. , Sia A. T. H. , Chong J. L.
Published: March 2003

Sixty patients in early labour were randomly allocated to one of three groups. The control group received intrathecal fentanyl 25 µg, the ropivacaine group received intrathecal fentanyl 25 µg and ropivacaine 2.5 mg while the bupivacaine group received intrathecal fentanyl 25 µg and bupivacaine 2.5 mg. The incidence of pruritus was 100% in controls, compared with 85% in the ropivacaine group (not significant) and 75% in the bupivacaine group (p = 0.003). The severity of pruritus was significantly less in the ropivacaine (p = 0.006) and bupivacaine (p = 0.001) groups. Most patients developed pruritus by 30 min. Pruritus above the abdomen was not reduced in patients receiving local anaesthetics. There were no significant differences in the mean pain visual analogue score, systolic blood pressure, maternal heart rate and upper level of reduced pin‐prick sensation in the first 30 min. Intrathecal ropivacaine and, more so, intrathecal bupivacaine reduce the incidence and severity of pruritus from intrathecal fentanyl for labour analgesia.
Evaluation of the use of the Flexiblade
Authors: Perera C. N. , Wiener P. C. , Harmer M. , Vaughan R. S.
Published: March 2003

The Flexiblade is a laryngoscope which has a ‘flexible’ blade. The ‘front’ half of the blade can be moved in an anterior direction during laryngoscopy, enhancing the view of the glottis. The degree of movement can be controlled with the lever. We studied 200 ASA 1 and 2 adult patients requiring tracheal intubation and the patients acted as their own controls. The view of the larynx was improved in 93% of the cases when the vocal cords were not completely visible at laryngoscopy with the lever in the neutral position. Ninety‐seven per cent of patients with a Cormack and Lehane grading of 2 at normal laryngoscopy were transformed to grade 1 when the lever of the Flexiblade was depressed and 84% of cases with a grading of 3 were transformed to grade 2 or 1. In four patients, there was deterioration in the view of the cords: three patients with grade 1 were transformed to grade 2 and one with grade 2 to grade 3. There was no improvement in one case with grade 2 and three with grade 3.
The role of a high‐dependency unit in a regional obstetric hospital
Authors: Ryan M. , Hamilton V. , Bowen M. , McKenna P.
Published: March 2003

The aim of our study was to review a series of critically ill patients admitted to a high‐dependency unit (HDU) in a regional obstetric centre, to assess our HDU utilisation rate and to determine the indications for and rate of transfer to an intensive care unit (ICU) in a tertiary referral centre. A 4‐year retrospective review of case notes and HDU/ICU registers was performed. One hundred and twenty‐three patients were admitted to the HDU in the 2 years following its inception, representing 1.02% of all deliveries. Obstetric complications accounted for 81.3% of admissions. Seventeen patients were admitted to an ICU during the study period; 12 (0.08%) were transferred before and five (0.04%) after the development of HDU facilities (p = 0.25). The advantages of a HDU within this setting include the concurrent availability of expert obstetric care and critical care management, the avoidance of the hazards of emergency transport and improved continuity of antenatal and postnatal care.
Regional anaesthesia for limb surgery – before or after general anaesthesia A survey of anaesthetists in the Oxford region
Authors: Kadry M. A. , Rutter S. V. , Popat M. T.
Published: March 2003

We conducted a postal survey of 221 anaesthetists in the Oxford region to determine their views and actual clinical practice regarding regional anaesthesia in adult patients undergoing limb surgery, when a combined regional and general anaesthetic was planned. Of the 162 respondents (73.3%), 142 (87.6%) regularly practised regional blocks for limb surgery in adult patients. For all the regional anaesthetic techniques in question, more anaesthetists felt it was safer to perform these blocks before induction of general anaesthesia than after induction. However, their actual practice varied markedly from their views, with more anaesthetists performing these blocks after general anaesthesia. Overall, trainees performed blocks before induction of general anaesthesia more often than consultants (p = 0.047).
Intravesical pressure and the TUR syndrome
Authors: Gray R. A. , Lynch C. , Hehir M. , Worsley M.
Published: March 2003

Intravesical pressure was measured continuously during 35 transurethral prostate resections using a fine suprapubic catheter. Absorption of irrigating fluid was detected by tagging it with ethanol and sampling the expired breath using an alcohol meter. Higher mean (SD) intravesical pressure was demonstrated in those patients who absorbed irrigating fluid (19.1 (7.7) mmHg) than in those who did not (12.4 (6.5) mmHg; p = 0.00004). Higher peak pressures were also demonstrated among absorbing patients. Traditional risk factors for fluid absorption, such as operator experience and resectate mass, were found to correlate with pressure exposure over time. Exposure to supranormal bladder pressure over time is the final common path for all causes of absorption. Vesical pressure monitoring may be a valuable feedback tool during difficult resections or operator training.
A prospective survey of intra‐operative critical incidents in a teaching hospital in a developing country
Authors: Khan F. A. , Hoda M. Q.
Published: March 2003

Critical incident monitoring has the advantage of identifying a potential risk to the patient without it necessarily resulting in morbidity. An added advantage in developing countries is the low cost involved in introducing the programme. This paper analyses the incidents reported from the operating room suite in a teaching hospital in a developing country from August 1997 to 31 December 1999. During the period, 20 819 anaesthetics were administered and 329 incidents were reported (1.58% of the cases). Seventy‐three per cent of the incidents were reported in patients of ASA grade 1 or 2. Thirty‐nine per cent occurred during induction, 51% during maintenance and 10% during emergence. Human error was the cause in 41%, equipment error in 50% and system error in 8.5%. Twenty‐two per cent of the incidents resulted in minor, and 13% in major physiological disturbance. The technique has been found useful in identifying trends and selecting issues to be discussed in departmental quality assurance meetings, but requires persistent motivation of the reporting staff.
Pre‐emptive analgesia with local anaesthetic for herniorrhaphy
Authors: Gill P. , Kiani S. , Victoria B. A. , Atcheson R.
Published: March 2003

There is little evidence that local anaesthetics produce pre‐emptive analgesia and one reason may be the short duration of action of the drugs studied. We examined the pre‐emptive analgesic effect of a bupivacaine field block on postoperative pain in 40 patients following herniorrhaphy in a double‐blind, randomised trial. Patients received the block either after induction but before surgery, or after surgery but before the end of anaesthesia. There was no difference in pain scores or analgesic consumption up to 7 days after surgery between the two groups. We have demonstrated that bupivacaine does not appear to provide significant pre‐emptive analgesia following a field block for herniorrhaphy. This study does not support the hypothesis that pre‐emptive analgesia with local anaesthetic depends upon the duration of action of the drug.
Management of comatose head‐injured patients: are we getting any better?
Authors: Wilkins I. A. , Menon D. K , Matta B. F.
Published: March 2003

This re‐survey of neurosurgical centres was conducted to determine whether the publication of management guidelines has resulted in changes in the intensive care management of severely head‐injured patients (defined as Glasgow Coma Score < 9) in the UK and Ireland. Results were compared with data collected from a similar survey conducted 2 years earlier. Almost 75% of centres monitor intracranial pressure in the majority of patients and 80% now set a target cerebral perfusion pressure of > 70 mmHg. The use of prolonged hyperventilation (> 12 h) is declining and the target Paco2 is now most commonly > 4 kPa. More centres maintain core temperature < 36.5 °C. Although wide variations in the management of severely head‐injured patients still exist, we found evidence of practice changing to comply with published guidelines.
Neuromuscular monitoring in myasthenic syndrome
Authors: Itoh H. , Shibata K. , Nitta S.
Published: March 2003

We describe the anaesthetic management of a 72‐year‐old man with myasthenic syndrome. Pre‐operatively, he was treated with 3,4‐diaminopyridine and showed a strong hand grip. During general anaesthesia with nitrous oxide and sevoflurane in oxygen, a mechanomyograph and two accelerographs were set up for the hands and left foot to monitor neuromuscular function. Insufficient force and acceleration of contraction with 1 Hz stimulation was observed in the hands. In the foot, the twitches produced by 1 Hz and train‐of‐four stimulation could barely be detected using the accelerograph, and the train‐of‐four ratio fluctuated between 70 and 100%. No neuromuscular blocking drugs were used during surgery. After discontinuation of sevoflurane, responses to train‐of‐four stimulation remained small, but a strong response to tetanic stimulation was observed, with post‐tetanic facilitation. Extubation was successful, and recovery from anaesthesia was uneventful. Tetanic stimulation and post‐tetanic facilitation are important in monitoring neuromuscular function in patients with myasthenic syndrome whose train‐of‐four responses are insufficient.
The arterial tourniquet: pathophysiological consequences and anaesthetic implications
Authors: Kam P. C. A. , Kavanaugh R. , Yoong F. F. Y.
Published: March 2003

The arterial tourniquet is widely used in upper and lower extremity surgery and in intravenous regional anaesthesia. The local and systemic physiological effects and the anaesthetic implications are reviewed. Localised complications result from either tissue compression beneath the cuff or tissue ischaemia distal to the tourniquet. Systemic effects are related to the inflation or deflation of the tourniquet. Safe working guidelines for the application of an arterial tourniquet have not been clearly defined.
Anaesthesia for insertion of bone‐anchored hearing aids in children: a 7‐year audit
Authors: Jones S. E. F. , Dickson U. , Moriarty A.
Published: March 2003

Forty‐three children, aged 23 months to 14 years, received 102 anaesthetics for insertion of bone‐anchored hearing aids, each lasting approximately 30–60 min. Forty of the children had a recognised syndrome involving the head and neck, including Goldenhar's and Treacher Collin's syndrome. The incidence of congenital heart disease was 19%. Pre‐existing conditions, anaesthetic technique, grade of intubation, complications and discharge were audited. Sixteen of the patients were classified as Grade 3 or 4 intubations. Over the 7 years, laryngeal mask airway usage increased for airway maintenance rather than tracheal intubation, as did the use of propofol for induction rather than inhalational methods. Intra‐operative complications (5.9%) were related to the airway, and postoperative ones (17.6%) mainly to nausea and vomiting. Surgery was performed as a day case in 71% of the patients despite some long‐distance travel.
The effect of prophylactic metaraminol on systemic hypotension caused by induction of anaesthesia with propofol in patients over 55 years old*
Authors: Chiu C. L. , Tew G. P. , Wang C. Y.
Published: March 2003

We conducted a double‐blind, randomised, placebo‐controlled study evaluating the efficacy of prophylactic metaraminol for preventing propofol‐induced hypotension. Thirty patients aged 55–75 years undergoing general anaesthesia were randomly allocated to receive either metaraminol 0.5 mg or saline before administration of fentanyl 1 µg.kg−1 and propofol 2 mg.kg−1. Induction of anaesthesia was associated with a decrease in mean and systolic arterial pressure in both groups (p = 0.0001). However, there was no significant difference between the two groups. These results show that prophylactic use of metaraminol 0.5 mg does not prevent the decrease in blood pressure following fentanyl and propofol induction in older patients.
The effect of the Lockit epidural catheter clamp on epidural migration: a controlled trial
Authors: Clark M. X. , O'Hare K. , Gorringe J. , Oh T.
Published: March 2003

We investigated the efficacy of using the Lockit epidural catheter clamp in preventing epidural catheter migration in patients receiving postoperative analgesia via an epidural infusion after major surgery. Patients were randomly allocated to receive either a standard epidural dressing, a coiled catheter with transparent adhesive dressing and tape (n = 54), or the Lockit epidural catheter clamp (n = 48). There was no movement from the insertion position in 88% of the Lockit group compared with only 28% in the standard group (p < 0.001). Outward migration of > 2 cm occurred in 26% of the standard group compared with just 6% of the Lockit group (p < 0.01). Inward migration of > 1 cm occurred in 17% of the standard group but in none of the Lockit group (p < 0.01). Catheter migration was assessed as being the cause of analgesic failure in 15% of the standard group but in only 4% of the Lockit group (p < 0.05). We conclude that the Lockit epidural catheter clamp significantly reduces catheter migration in a safe and non‐invasive fashion.
Airway obstruction with cricoid pressure and lateral tilt
Authors: Hocking G. , Roberts F. L. , Thew M. E.
Published: March 2003

We studied the effect of cricoid pressure and lateral tilt on airway patency during ventilation by facemask in a simulated obstetric setting. The lungs of 50 patients were ventilated by facemask and Guedel airway using a Nuffield Penlon 200 ventilator and Bain system with standard settings. Expired tidal volumes and peak inspiratory pressures were recorded for 10 breaths in each of four combinations: supine with no cricoid pressure, supine with cricoid pressure, 15° lateral tilt with no cricoid pressure and 15° lateral tilt with cricoid pressure. The timing of cricoid pressure was randomised and blinded to all observers. In both supine and tilted positions, cricoid pressure produced a reduction in tidal volume (p < 0.001) and an increase in peak inspiratory pressure (p < 0.001). Cricoid pressure with lateral tilt did not produce any additional airway obstruction to that in the supine position. Complete airway obstruction (tidal volume < 200 ml) resulted on three occasions, all with cricoid pressure applied.
The ability of breathing system filters to prevent liquid contamination of breathing systems: a laboratory study*
Authors: Wilkes A. R.
Published: March 2003

The ability of 29 different breathing system filters (five pleated hydrophobic and 24 electrostatic) to prevent the passage of water was assessed. Five, 10 or 20 ml of water was added on to the patient side of the filter during ventilation of a patient model with the filter layer orientated either horizontally or vertically. Water did not pass through the filter layer during any of the 30 tests on the pleated hydrophobic filters. In contrast, water passed through the filter layer in 39 of the 144 tests on the electrostatic filters (27%; 95% CI for difference between the filter types 14–35%; p = 0.0004). For electrostatic filters, a smaller internal volume, a larger volume of water added, and having the filter layer horizontal rather than vertical all significantly increased the probability of water penetration. Although pleated hydrophobic filters would protect the breathing system against liquid contamination, electrostatic filters can also be used, provided the internal volume is chosen appropriately and the filter layer is vertical.
Sevoflurane vs. isoflurane: a clinical comparison in day surgery*
Authors: Elcock D. H. , Sweeney B. P.
Published: March 2003

Discharge times after ambulatory surgery are determined by postoperative complications and in particular by the presence and severity of nausea and vomiting. Sevoflurane has become a popular agent for day‐case surgery despite little evidence of clear advantages over current alternatives. We compared this agent with isoflurane in day‐case patients undergoing knee arthroscopy in order to quantify the incidence of complications associated with each agent. One hundred and eighty patients received a standardised anaesthetic induction with propofol and fentanyl followed by maintenance with either isoflurane or sevoflurane. Standardised postoperative analgesic and anti‐emetic drugs were prescribed. Any intra‐operative cardiovascular or respiratory instability was recorded. After surgery, nausea, vomiting and pain were assessed. Almost all patients made an uneventful recovery and were discharged as scheduled. There was a significantly higher incidence of complications in the sevoflurane group. These included the presence of nausea and vomiting, and cardiovascular and respiratory complications. We found nothing to commend the routine use of sevoflurane rather than isoflurane in the context of day case anaesthesia.
Blood component use in critically ill patients
Authors: Rao M. P. , Boralessa Harsha , Morgan C. , Soni N. , Goldhill D. R. , Brett S. J. , Boralessa Hari , Contreras M.
Published: March 2003

SummaryThis prospective observational study was conducted to assess the current transfusion practice in critically ill patients. One thousand two hundred and forty‐seven consecutive critically ill patients admitted between February 1999 and October 1999 were included in the study. Overall 666 (53%) patients were administered red cells. Transfused patients had significantly higher intensive care unit␣mortality but also had higher Acute Physiology and Chronic Health Evaluation II scores and longer durations of stay. The average pretransfusion haemoglobin concentration was < 9 g.dl−1in 75% of transfusion episodes. The common indications for transfusion were low haemoglobin (72%) and haemorrhage (25%). Overall, 202 (16%) and 281 (22%) of the patients were transfused platelets and fresh frozen plasma, respectively. The indications for transfusion were haemorrhage, low platelet counts, prolonged prothrombin time or to provide cover for invasive interventions. Most platelet transfusions were given at values in the order of 50–100 × 109.l−1. The pretransfusion platelet count varied according to the indications for transfusion. This study showed that transfusion practice is consistent and that in general there does not seem to be an excessive use of blood components in critically ill patients.
The variable effect of low‐dose volatile anaesthetics on the acute ventilatory response to hypoxia in humans: a quantitative review
Authors: Pandit J. J.
Published: March 2003

Summary The purpose of this study was to review published studies (identified by a Medline‐assisted search) on the effect of  ? 0.2 minimal alveolar concentration (MAC) halothane, isoflurane, enflurane and sevoflurane on the acute hypoxic ventilatory response in healthy subjects. Each article was examined for the anaesthetic agent, speed of hypoxic stimulus, background carbon dioxide and subject stimulation (audiovisual or painful). Analysis of variance was used to assess the significance of the influence of each of these factors on the standardised hypoxic response (the acute hypoxic ventilatory response in l.min−1 in the presence of anaesthetic, expressed as a fraction of the response without anaesthetic). There were 37 separate studies within 21 published articles. The main factor influencing standardised hypoxic response was anaesthetic agent (p < 0.002). A second influential factor was subject stimulation (p < 0.014), but the interaction term of agent and stimulation was also significant (p < 0.039), suggesting that the influence of stimulation varied with the agent used. Speed of hypoxia and background carbon dioxide had no influence. In contrast to previous authors' assertions that study conditions have a major impact on the acute ventilatory response to hypoxia, this review suggests that the main determinant is simply the anaesthetic agent used. The review also highlights important gaps in the research literature, which may direct future research in this field. In particular, it would seem important to investigate the influence of arousal when different anaesthetic agents are used.
Provision of postoperative epidural services in NHS hospitals
Authors: Austin J.
Published: March 2003

Summary To describe facilities for postoperative epidurals in UK National Health Service Hospitals, a questionnaire was sent to each hospital performing surgery below the head and neck. Of 271 hospitals, 256 replied (95%). While almost all offer postoperative epidurals, only 78 (30%) offer them to all surgical disciplines. Most hospitals rely on acute pain nurses for troubleshooting during the day, and on trainee anaesthetists after hours. Administration is most commonly by continuous infusion. There was no restriction on the use of epidural opioids in 67% of hospitals. Most (96%) hospitals have a protocol for epidural care, although the specified level of monitoring varies widely. There is no consensus of practice on removal of epidural catheters relative to anticoagulation. Levels of training in epidural care also vary widely. Two hundred and thirty‐six hospitals (92%) have an acute pain team. Despite the expansion in acute pain services, facilities for postoperative epidurals are deficient in many NHS hospitals.
A comparison of oral transmucosal fentanyl and oral midazolam for premedication in children
Authors: Howell T. K. , Smith S. , Rushman S. C. , Walker R. W. M. , Radivan F.
Published: March 2003

Summary Oral transmucosal fentanyl citrate (OTF) was compared with midazolam as a premedicant in a prospective, randomised, placebo‐controlled, double‐blind trial. Eighty children (ASA grade 1or 2, aged 3–9 years) who presented for tonsillectomy were randomly allocated to receive either 2.5 ml OTF (15–20 µg.kg−1) in a lollipop format and 0.5 ml.kg−1 placebo syrup, or midazolam syrup (0.5 mg.kg−1) and a placebo lollipop (2.5 ml). The acceptability of sedation, anxiety and compliance with anaesthetic induction were assessed. The children were given an ‘emergence’ score for their recovery. Analgesia requirements, the incidence of vomiting, itching and any behavioural changes were assessed for 6 h postoperatively. Oral transmucosal fentanyl citrate was as effective as midazolam in aiding compliance with anaesthesia, but is significantly better in its appeal to children (p < 0.001) and emergence (p < 0.001) characteristics. In conclusion, OTF may be particularly useful as a premedicant in paediatric practice.
Attitudes of patients and anaesthetists to informed consent for specialist airway techniques*
Authors: Bray J. K. , Yentis S. M.
Published: March 2003

We investigated the attitudes of 96 patients and 163 anaesthetists to the need for obtaining informed consent before specialist airway techniques. Participants were asked to score six questions using a numerical scale, as to whether they thought consent was necessary before specific procedures, particularly in relation to fibreoptic intubtion used for teaching or maintaining skills. Significant differences in opinion were found between patients and anaesthetists despite a wide range of views. Overall, patients felt that specific consent was required for non‐routine techniques, whilst anaesthetic respondents felt this was unnecessary, even if teaching. We conclude that guidance in obtaining consent is needed to support anaesthetists wishing to practice or teach fibreoptic intubation.
The use of anaesthetic rooms for induction of anaesthesia: a postal survey of current practice and attitudes in Great Britain and Northern Ireland
Authors: Bromhead H. J. , Jones N. A.
Published: March 2003

Summary A postal survey was sent to all anaesthetic departments in the UK to identify current practice and gain insight into anaesthetists' attitudes regarding the use of anaesthetic rooms for induction of general anaesthesia. Replies were received from 247 (88%) departments. Of these, 10 (4%) departments routinely anaesthetise all patients in theatre. The main reason for change was patient safety. Of those who routinely use the anaesthetic room for induction of anaesthesia, only 5% have made provision to change to in‐theatre induction. An estimated £30 million has been spent on equipping anaesthetic rooms since 1994; with the result that 91% of departments where anaesthetic room induction occurs, now have monitoring that complies with the current Association of Anaesthetists of Great Britain and Ireland guidelines. The majority of the respondents who use anaesthetic rooms perceived induction in theatre to result in reduced efficiency, increased patient anxiety, a worse teaching environment and no improvement in patient safety. This was in contrast to the attitudes of respondents from hospitals where in‐theatre induction occurs. Only 9.7% of all respondents believed that clinical governance would necessitate a change to anaesthetizing all patients in theatre compared to 25% who believed that the increasing costs of monitoring equipment would lead to a change. Overall 79% of respondents prefer to use the anaesthetic room, 16% prefer in‐theatre induction and 5% expressed no preference. However, of those who routinely anaesthetise in theatre, 70% thought it to be preferable.
The importance of metabolic rate and the folly of body surface area calculations
Authors: Gibson S , Numa A
Published: March 2003

Summary Mathematical formulae to calculate body surface area from measurements of height, weight and other parameters date from the late 19th century. Drug doses, fluid therapy, caloric requirements and physiological parameters such as cardiac output, glomerular filtration rate and a variety of respiratory function parameters are all frequently expressed in terms of a body surface area. Body surface area is often used in preference to body mass (weight). However, the original rationale for using body surface area as an estimate for metabolic rate has never been tested and the algorithms used to approximate body surface area have little evidence to support their use in this role. Recent developments in technology using indirect calorimetry allow easy measurement of metabolic rate in the clinical setting. Such measurements should be used for standardisation when weight alone is considered inadequate.
Laboratory and clinical comparisons of the Streamlined Liner of the Pharynx Airway (SLIPA™) with the laryngeal mask airway*
Authors: Miller D. M. , Light D.
Published: March 2003

SummaryThe Streamlined Liner of the Pharynx Airway (SLIPA™) is a new inexpensive disposable supraglottic airway designed to seal without the use of an inflatable cuff. It comprises a hollow blow‐moulded soft plastic airway shaped to form a seal in the pharynx. Being hollow, liquid entrapment is possible and this may provide effective protection against aspiration. A model silicone rubber pharynx with an ‘oesophageal’ tube for injecting volumes of regurgitant liquid was designed to evaluate the SLIPA™ and the standard and ProSeal laryngeal mask airways during positive‐pressure ventilation. A linear relationship between the volume ‘regurgitated’ and the volume ‘aspirated’ was found with the laryngeal mask airway and the ProSeal laryngeal mask airway with the drainage tube clamped. Both the ProSeal laryngeal mask airway with an open drainage tube and the SLIPA™, but not the standard laryngeal mask airway, provided effective protection against ‘aspiration’ during positive‐pressure ventilation using the model. In a clinical study, 120 patients were randomly allocated to receive controlled ventilation of the lungs via the standard laryngeal mask airway or the SLIPA™. Both devices were equally easy to insert and satisfactory for airway management.
Role of fault interactions in controlling synrift sediment dispersal patterns: Miocene, Abu Alaqa Group, Suez Rift, Sinai, Egypt
Authors: Gupta  , Underhill  , Sharp  , Gawthorpe
Published: March 2003

Although fault growth is an important control on drainage development in modern rifts, such links are difficult to establish in ancient basins. To understand how the growth and interaction of normal fault segments controls stratigraphic patterns, we investigate the response of a coarse‐grained delta system to evolution of a fault array in a Miocene half‐graben basin, Suez rift. The early Miocene Alaqa delta complex comprises a vertically stacked set of footwall‐sourced Gilbert deltas located in the immediate hangingwall of the rift border fault, adjacent to a major intrabasinal relay zone. Sedimentological and stratigraphic studies, in combination with structural analysis of the basin‐bounding fault system, permit reconstruction of the architecture, dispersal patterns and evolution of proximal Gilbert delta systems in relation to the growth and interaction of normal fault segments. Structural geometries demonstrate that fault‐related folds developed along the basin margin above upward and laterally propagating normal faults during the early stages of extension. Palaeocurrent data indicate that the delta complex formed a point‐sourced depositional system developed at the intersection of two normal fault segments. Gilbert deltas prograded transverse into the basin and laterally parallel to faults. Development of the transverse delta complex is proposed to be a function of its location adjacent to an evolving zone of fault overlap, together with focusing of dispersal between adjacent fault segments growing towards each other. Growth strata onlap and converge onto the monoclinal fold limbs indicating that these structures formed evolving structural topography. During fold growth, Gilbert deltas prograded across the deforming fold surface, became progressively rotated and incorporated into fold limbs. Spatial variability of facies architecture is linked to along‐strike variation in the style of fault/fold growth, and in particular variation in rates of crestal uplift and fold limb rotation. Our results clearly show that the growth and linkage of fault segments during fault array evolution has a fundamental control on patterns of sediment dispersal in rift basins.
Characteristics and origin of underpressure system in the Shiwu Fault Depression, south‐east Songliao Basin, China
Authors: He  , Middleton  , Tang
Published: March 2003

The vertical characteristics of underpressure, pore fluids and sealing condition in the Shiwu Fault Depression, south‐east Songliao Basin, are investigated. Based on the pore pressure data from drill stem tests collected from 40 wells, the vertical distribution of pore pressure in this depression consists of a shallow hydrostatic pressure system and a deep underpressure system. The observed low pressures range from about 4 to 10 MPa in the depth interval of about 1550–2800 m. The pore water chemistry data document that the ionic evaporite trends of the pore water in the underpressure zone are different from overlying sediments in the hydrostatically pressured section, indicating that the underpressure system is sealed. The study indicates that the depression has undergone rapid deposition in a rift period during the Cretaceous followed by a long‐term slow uplift and erosion in the Tertiary. On the basis of the modelled results of the abnormal pressure evolution in a typical cross‐section using a two‐dimensional numerical flow model, we believe that the predecessor of the underpressure system was an overpressure system. Since the end of the Cretaceous, the observed underpressure system has developed as a result of a geotemperature decrease ranging from 30 to 70 °C, owing to palaeoheat flow reduction and long‐term uplift and erosional cooling. The mudstones below a depth of 1550 m in the deep subnormal pressure system have small measured porosities ranging from 4% to 1.2% with calculated permeability of about 10−21–10−24 m2. The observed underpressure can be modelled if we assign permeabilities below 10−20 m2 with a linear reduction of geotemperature. The geotemperature decrease, in combination with very low permeability in the Lower Cretaceous mudstones, is therefore a possible origin for the formation of the underpressure system in this depression.
A flexural model for the Paradox Basin: implications for the tectonics of the Ancestral Rocky Mountains
Authors: Barbeau D. L.
Published: March 2003

The Paradox Basin is a large (190 km × 265 km) asymmetric basin that developed along the southwestern flank of the basement‐involved Uncompahgre uplift in Utah and Colorado, USA during the Pennsylvanian–Permian Ancestral Rocky Mountain (ARM) orogenic event. Previously interpreted as a pull‐apart basin, the Paradox Basin more closely resembles intraforeland flexural basins such as those that developed between the basement‐cored uplifts of the Late Cretaceous–Eocene Laramide orogeny in the western interior USA. The shape, subsidence history, facies architecture, and structural relationships of the Uncompahgre–Paradox system are exemplary of typical ‘immobile’ foreland basin systems.

Along the southwest‐vergent Uncompahgre thrust, ∼5 km of coarse‐grained syntectonic Desmoinesian–Wolfcampian (mid‐Pennsylvanian to early Permian; ∼310–260 Ma) sediments were shed from the Uncompahgre uplift by alluvial fans and reworked by aeolian‐modified fluvial megafan deposystems in the proximal Paradox Basin. The coeval rise of an uplift‐parallel barrier ∼200 km southwest of the Uncompahgre front restricted reflux from the open ocean south and west of the basin, and promoted deposition of thick evaporite‐shale and biohermal carbonate facies in the medial and distal submarine parts of the basin, respectively. Nearshore carbonate shoal and terrestrial siliciclastic deposystems overtopped the basin during the late stages of subsidence during the Missourian through Wolfcampian (∼300–260 Ma) as sediment flux outpaced the rate of generation of accommodation space. Reconstruction of an end‐Permian two‐dimensional basin profile from seismic, borehole, and outcrop data depicts the relationship of these deposystems to the differential accommodation space generated by Pennsylvanian–Permian subsidence, highlighting the similarities between the Paradox basin‐fill and that of other ancient and modern foreland basins. Flexural modeling of the restored basin profile indicates that the Paradox Basin can be described by flexural loading of a fully broken continental crust by a model Uncompahgre uplift and accompanying synorogenic sediments. Other thrust‐bounded basins of the ARM have similar basin profiles and facies architectures to those of the Paradox Basin, suggesting that many ARM basins may share a flexural geodynamic mechanism. Therefore, plate tectonic models that attempt to explain the development of ARM uplifts need to incorporate a mechanism for the widespread generation of flexural basins.
Clinical aspects of indocyanine green pharmacokinetics following portal vein administration
Authors: Nishi Shinichi , Shindo Mitsuo , Abe Junko , Asada Akira
Published: March 2003

Aims
 This study was performed to demonstrate that measurement of the clearance of indocyanine green (ICG) following portal vein administration (CLpv) is more useful than that following peripheral vein administration (CLiv) for evaluating intrinsic clearance and hepatic blood flow.

Methods
 Eight patients, aged 55.9±8.8 years, who underwent partial hepatectomy were studied. ICG was administrated to all patients via peripheral and portal veins before and after enflurane anaesthesia and soon after surgery. ICG concentrations were measured by h.p.l.c. Non‐compartmental analysis was applied to the ICG time‐concentration data obtained. The area under the curve (AUC), clearance (CL), mean residence time (MRT) and volume of distribution (V  ) were calculated using this method of analysis.

Results
 CLpv was significantly decreased from 26.4±13.2 ml kg−1 min−1 before anaesthesia, to 19.5±7.0 (P<0.05) and 12.7±5.3 (P<0.01) ml kg−1 min−1, respectively, during anaesthesia and after partial hepatectomy; These values were 72.1% (P<0.01) and 48.5% (P<0.01) of that observed at percutaneous transhepatic portography (PTP). CLiv was significantly decreased from 14.6±5.3 ml kg−1 min−1 before anaesthesia, to 9.4±3.6 (P<0.05) and 9.8±4.1 (P<0.05) ml kg−1 min−1, respectively, after partial hepatectomy and 12 h after operation; These values were 68.9% (P<0.05) and 73.5% (P<0.05) of the value at PTP. The other pharmacokinetic parameters examined, V  and MRT, did not change significantly during anaesthesia or after surgery.

Conclusion
 The clearance of ICG after portal administration was useful for estimating hepatic blood flow and intrinsic clearance in perioperative management of liver surgery.
Nasal absorption of hydroxocobalamin in healthy elderly adults
Authors: Van Asselt D. Z. B. , Merkus F. W. H. M. , Russel F. G. M. , Hoefnagels W. H. L.
Published: March 2003

Aims
 To investigate the nasal absorption of hydroxocobalamin in 10 healthy elderly adults.

Methods
 In a cross‐over study, blood samples were collected before administration of the drug and after 10, 20, 30, 40, 60, 120, 180 and 240 min. The plasma cobalamin concentration was determined by competitive radioisotope binding technique.

Results
 The maximal plasma cobalamin concentration (Cmax ) after nasal administration of 750 μg hydroxocobalamin was 1900±900 pmol l−1 (mean±s.d.). The maximal plasma cobalamin concentration was reached in 35±13 min (tmax ). The Cmax after nasal administration of 1500 μg hydroxocobalamin was 3500±2500 pmol l−1 with a tmax of 28±16 min. Both the AUC(0,240 min) and AUC(0,00) increased significantly with an increase of the dose from 750 μg to 1500 μg (P=0.037 and P=0.028, respectively). The nasal spray was well tolerated. No signs of irritation or local sensitivity were noted.

Conclusions
 The nasal absorption of hydroxocobalamin in healthy elderly adults is rapid, high and well tolerated.