bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of topical benzocaine and lignocaine on upper airway reflex sensitivity
Authors: RAPHAEL J. H. , STANLEY G. D. , LANGTON J. A. 
Published: February 2007

SummaryWe studied the degree and duration of effect on upper airway reflex sensitivity of oral benzocaine lozenges, nebulised lignocaine and lignocaine sprayed onto the vocal cords under direct vision, using low concentrations of ammonia as a stimulus to upper airway receptors. Ten minutes after the administration of oral benzocaine 20 mg the threshold response of the upper airway to ammonia (NH3TR) had risen significantly from baseline mean (SEM) of 680 (95) to 975 (109)ppm of ammonia with a return to baseline values after 25min (n = 8, p < 0.05, repeated measures of ANOVA; p < 0.001, t‐test). A direct spray of lignocaine 100mg onto the vocal cords resulted in a significant elevation in NH3TR from a baseline mean (SEM) of 665 (81) to a maximum of 1600 (88)ppm of ammonia with a significant elevation in the threshold persisting for 100min (n = 7, p < 0.001, repeated measures of AN OVA; p < 0.05, t‐test). The application of 4% nebulised lignocaine 4ml significantly increased NH3 T R from a baseline mean (SEM) of 770 (56) to a maximum of 1190 (63)ppm of ammonia with a significant elevation in the threshold persisting for 30 min (n = 8, p < 0.001, repeated measures of ANOVA; p < 0.05, t‐test). The maximum elevations in NH3TR with the two methods of lignocaine delivery were significantly different (p < 0.01, 2‐way A NOVA).
Thoracic paravertebral space location
Authors: RICHARDSON J. , CHEEMA S. P. S. , HAWKINS J. , SABANATHAN S. 
Published: February 2007

SummaryThe major drawback of paravertebral space location using the traditional method of loss of resistance to air or saline is a failure rate of at least 10%. We investigated whether pressure measurement during needle advancement could improve reliability. Twenty‐nine blocks in 14 awake adult patients undergoing treatment for chronically painful neuralgic conditions of the chest or abdominal wall were studied. In erector spinae, the mean inspiratory pressure (29.5mmHg, SD 14.2), exceeded the expiratory pressure (19.4mmHg, SD 9.7). However, upon traversing the superior costo‐transverse ligament, there was a sudden lowering of pressures and the mean expiratory pressure (7.6 mmHg, SD 3.7) exceeded the inspiratory pressure (3.3 mmHg, SD 2.9). No negative pressures were recorded. Correct needle placement was confirmed by A ‘ray screening and contrast injection. All blocks were successful and uncomplicated. Location of the paravertebral space by this objective method of'pressure inversion’improves sensitivity and specificity and should lead to an improvement in the success rate of thoracic paravertebral analgesia.
Interactions of calcium channel blockers with non‐depolarising muscle relaxants in vitro
Authors: SEKERCI S. , TULUNAY M. 
Published: February 2007

Summary The effects of two calcium channel blockers (verapamil and nicardipine) on indirectly elicited muscle twitch and possible interactions between these drugs and non‐depolarising muscle relaxants (vecuronium, atracurium, pancuronium) were investigated using isolated rat phrenic nerve‐hemidiaphragm preparations. Both verapamil 10‐5 M and nicardipine 10‐6 M caused significant depression of twitch amplitude. Verapamil significantly increased vecuronium‐ and atracurium‐induced neuromuscular block, but not that produced by pancuronium. Nicardipine potentiated atracurium‐induced neuromuscular block but had no effect on pancuronium‐ and vecuronium‐induced twitch depression. Neostigmine 10‐6 M did not produce any significant changes in the maximal recovery of twitch depression induced with calcium channel blockers and muscle relaxants combinations; also, neostigmine had no effect on maximal recovery time of twitch depression.
A novel device for patient‐controlled sedation: laboratory and clinical evaluation of the Baxter Intermate LV250 infusor and patient‐control module
Authors: HAMID S. K. , WONG P. K. , CARMICHAEL F. , WHITE K. , ASBURY A. J. 
Published: February 2007

Summary The Baxter Intermate LV250 infusor is a large capacity, high flow mechanical infusor, designed to deliver viscous solutions and suspensions. The objective of the laboratory study was to evaluate the LV250 infusor when used with either 0.9% sodium chloride solution or an emulsion, propofol 1%. Following this, the LV250 infusor with the patient‐control module was assessed in the clinical setting as to its suitability for use in patient‐controlled sedation with a propofol and lignocaine mixture. Between reservoir volumes of 250 and 55 ml, the L V250 infusor was found to infuse a propofol 1% and lignocaine mixture at a lower flow compared with the sodium chloride solution, 170ml.h‐1 and 260ml.h‐1 respectively. The lower flow with the propofol mixture may be a result of its higher viscosity. All patients using the LV250 infusor for patient‐controlled sedation found it easy to use and stated that they were able to achieve their desired level of sedation. All patients maintained arterial oxygen saturations above 95%. The LV250 infusor performed reliably and with little inter‐device variation, and with the patient‐control module could be used as an alternative to electronic devices for providing patient‐controlled sedation. Compared with electronic infusors, its advantages include compactness and simplicity of design.
Doctor Dee's ether apparatus
Authors: SUDARSHAN G. , SONI A. K. , WELSH B. 
Published: February 2007

SummaryIn the early 1940s, Dr M. H. Armstrong‐Davison devised an apparatus for inhalational anaesthesia. The apparatus was essentially a combination of Water's to‐and‐fro soda‐lime canister and Hewitt's ether inhaler. The description of the apparatus is followed by a brief historical note on Dr Armstrong‐Davison.
Pre‐operative anxiety
Authors: PANDA N. , BAJAJ A. , PERSHAD D. , YADDANAPUDI L. N. , CHARI P. 
Published: February 2007

SummaryThe influence of the relative position on the operating list on pre‐operative anxiety was studied in 60 adult female ASA 1 patients undergoing major surgery. Thirty patients were placed first on the operating list (group 1) and 30 were given a time 4–5 h later (group 2). Each patient was visited on the evening prior to surgery and again on the morning of surgery. Anxiety was measured at each visit by objective criteria and part 1 of the State‐Trait Anxiety Inventory questionnaire. The pulse rate, systolic blood pressure and the State‐Trait Anxiety Inventory questionnaire scores were higher on the second visit than on the first (p< 0.001) in all patients. This increase was greater in group 2 than in group 1 (p<0.05). The evening anxiety scores were not correlated with those on the morning visit and could not predict them.
Doxacurium pharmacodynamics in children during volatile and opioid‐based anaesthesia
Authors: KERN C. , TASSONYI E. , ROUGE J.‐C. , WILDER‐SMITH O. H. G. , PITTET J.‐F. 
Published: February 2007

SummaryThe interaction between doxacurium and halothane, isoflurane or alfentanil has not been studied in children. Using the cumulative dose‐response technique and electromyography, we determined ED 50 and ED90 of doxacurium during halothane (n = 9), isoflurane (n= 12) or alfentanil (n = 9) based anaesthesia in children aged 2–10 years. Both isoflurane and halothane potentiated the effects of doxacurium compared to alfentanil. The ED50for doxacurium/halothane was 23.9μg.kg‐1 compared to 32.7 μg.kg‐1 for doxacurium/alfentanil. The ED90, for doxacurium j isoflurane was 32.7 μg.kg‐1 compared to 48.2 μg.kg‐1 doxacurium/alfentanil (p<0.05). There were no significant time course differences between the groups. When equipotent doses of doxacurium were used to provide muscle relaxation the duration of the neuromuscular block was similar in children who received qflentanil, halothane or isoflurane supplementation of N2O/O2 anaesthesia.
Respiratory pattern and rebreathing in the Mapleson A, C and D breathing systems with spontaneous ventilation
Authors: COOK L. B. 
Published: February 2007

SummaryA theoretical analysis is presented of the Mapleson A, C and D breathing systems when used in spontaneous respiration. The influence of the respiratory pattern is explained diagrammatically. Simple equations are derived, predicting the fresh gas flow required to prevent rebreathing with different respiratory patterns. Further equations allow the degree of rebreathing caused by inadequate fresh gas flow to be quantified. These are used to examine the effects of different respiratory patterns on the efficiency of the three systems. It is demonstrated that the single most important determinant of efficiency is the duration of the expiratory pause. The nature of the inspiratory and expiratory waveforms is less important and the I:E ratio far less important. The analysis suggests that the Mapleson A system will always be the most efficient of the three systems. The Mapleson C system will be efficient if inspiration is long and the expiratory pause is minimal. The Mapleson D system will be efficient if the expiratory pause is sufficiently long.
Leg and back pain after spinal anaesthesia involving hyperbaric 5% lignocaine
Authors: Salmela L. , Aromaa U. , Cozanitis D. A. 
Published: February 2007

SummaryFifty‐four patients, aged 27–90 years, who were given lignocaine 5% in 6.8% glucose solution for spinal anaesthesia were studied. Thirteen of these patients experienced pain in the legs and/or back after recovery from anaesthesia. The patients affected were younger (p<0.05) and the site of the dural puncture was higher (p <0.01) than those individuals without pain. Five of the 13 patients (38%) with pain and seven of the 41 patients (17%) without pain admitted to a high alcohol intake, which might be a contributing factor. Leg and/or hack pain is associated with the intrathecal use of hyperbaric 5% lignocaine.
Acid‐base management during cardiopulmonary bypass
Authors: Goldsack C. , Berridge J. C. 
Published: February 2007

SummaryControversy exists over which method of acid‐base management should be used during hypothermie cardiopulmonary bypass: the alpha‐stat method or the pH‐stat method. We surveyed 40 centres in the United Kingdom to assess current practice; whether practice has changed recently; and if so, why. Ten years ago, 31 centres (77.5%) used pH‐stat and seven (17.5%) used alpha‐stat. Currently nine centres (22.5%) are using pH‐stat, 25 (62.5%) are using alpha‐stat and four (10%) are using both. One centre (2.5%) has always used a modified pH‐stat technique, and one continues to use alpha‐stat in children and pH‐stat in adults. Twenty‐one of the 22 centres which have changed their practice did so because of increasing reports incriminating pH‐stat in postoperative morbidity, particularly cerebral dysfunction. Our results show a marked trend towards using alpha‐stat methods rather than the more traditional pH‐stat approach.
Endothelin‐1 concentrations and optimisation of arterial oxygenation and venous admixture by selective pulmonary artery infusion of prostaglandin E1 during thoracotomy
Authors: CHEN T.‐L. , LEE Y.‐T. , WANG M.‐J. , LEE J.‐M. , LEE Y.‐C. , CHU S.‐H. 
Published: February 2007

SummaryIn order to improve arterial oxygenation and venous admixture during one lung ventilation, the effect of selective infusion of prostaglandin Ei into the pulmonary artery of the ventilated lung was investigated in 12 adult patients undergoing thoracotomy. Patients’bronchi were intubated with a Mallinckrodt bronchial tube and ventilated with 66% oxygen in air. Cardiopulmonary factors such as systemic and pulmonary arterial pressures, pulmonary vascular resistance, blood gas analyses, cardiac output and airway pressure were measured before and during one‐lung ventilation; venous admixture (Qs/Qt) was calculated. Serial blood samples were taken from the pulmonary artery of the ventilated lung for endothelin‐1 estimation. One lung ventilation reduced the mean Pao2 from 42.1 (2.3)kPa to 11.8 (1.4)kPa (p < 0.001) and increased Qs/Qt from 10.8 (3.2)% to 39.2(4.7)% (p < 0.001). Pulmonary vascular resistance also increased from 167 (24) dyne.s.cm‐5 to 262 (38) dyne.s.cm‐5 (p < 0.05) with a corresponding increase of plasma endothelin‐1 (p < 0.05). After 30min of one lung ventilation, PGE, was infused continuously into the pulmonary artery of the ventilated lung at a rate which increased incrementally from 0.04–0.10 μg.kg‐1.min‐1. Pao2 increased to 20.7 (2.6) kPa (p < 0.01) and Qs/Qt decreased to 30.6 (3.5)% (p < 0.05). During the infusion, pulmonary vascular resistance reduced to 173 (30) dyne.s.cm‐5 (p < 0.01). The plasma endothelin‐1 concentration reached a plateau between the end of one lung ventilation (before closing the thorax) and 6h postoperatively. This correlated inversely with the pre‐operative forced expiratory volume in one second (r =— 0.68, p < 0.005), declining to normal values 72 h after operation. The selective infusion of PGEi into the pulmonary artery of the ventilated lung corrected pulmonary vasoconstriction and improved both arterial oxygenation and venous admixture during one lung ventilation for thoracotomy.
Patient‐controlled alfentanil
Authors: IRWIN M. G. , JONES R. D. M. , VISRAM A. R. , KENNY G. N. C. 
Published: February 2007

SummaryWe have compared the opioid effects of a patient‐demand, target‐controlled infusion of alfentanil (n = 10), with patient‐controlled bolus administration of morphine (n = 10) following major spinal surgery in Chinese patients aged from 11 to 67 years. The same general anaesthesia regimen was used in all patients. One group of patients were given intra‐operative morphine analgesia followed by postoperative intravenous morphine patient‐controlled analgesia, while the other group received an intra‐operative target‐controlled infusion of alfentanil. Following surgery, the alfentanil group were given control of a handset and were able to increase the target alfentanil plasma level in 5ng.ml‐1 increments with a 2‐min lockout interval. If analgesia was not demanded within a 15‐min period, the computer reduced the target concentration by 5ng.ml‐1. All patients had continuous pulse oximetry monitoring and hourly recording of pain, sedation, nausea scores and respiratory rate. Patients receiving alfentanil had the target concentration noted hourly and four blood samples taken during the first 24 h for measurement of plasma alfentanil concentrations by high performance liquid chromatography. The alfentanil infusion system was equally effective as an analgesic technique when compared with morphine patient‐controlled analgesia. There were no hypoxaemic episodes (oxygen saturation <94%), no difference in sedation scores and the incidence of nausea (30%) was the same in both groups. There was a significantly (p < 0.001) lower respiratory rate in the alfentanil group compared with patients receiving morphine at, clinically assessed, equianalgesia. The predicted plasma alfentanil concentrations increased rapidly from about 30ng.ml‐1 during the first 4 h to around 100ng.ml‐1 at the end of the 24‐h study period. The precision of the target‐controlled infusion system was 75.4% and the mean prediction error (bias) 58.1%, suggesting an underestimation of the measured alfentanil concentrations by the alfentanil infusion system in these Chinese patients.
Low pressure leakage in anaesthetic machines
Authors: SOMPRAKIT P. , SOONTRANAN P. 
Published: February 2007

SummaryPositive and negative pressure tests for checking the low pressure section of 36 anaesthetic machines in order to detect gas leaks were prospectively compared. The low pressure section was checked by the soap bubble test as a‘gold standard‘. The leakage rate was 86.1%. The sensitivity and specificity of the positive pressure tests were 92% and 100% respectively, whilst the sensitivity and specificity of the negative pressure test were both 100%. However, seven machines revealed a leak which was only detected by the positive pressure test: this problem arose through defects in the emergency oxygen flush devices which allowed oxygen to leak around the valve even though it was in the‘off’position. This might reduce the specificity of the negative pressure test to 41.7%. For security, both tests should be carried out in series; the positive pressure test followed by the negative pressure test. The possibility of gaseous leakage around the oxygen flush device is not generally recognised. This study emphasises the need for skilled servicing of anaesthetic machines on a regular basis.
Topical ibuprofen for skin analgesia prior to venepuncture
Authors: Smith A. J. , Eggers K. A. , Stacey M. R. W. , Power I. 
Published: February 2007

SummaryThe analgesic effect of topical ibuprofen was investigated in ten volunteers. There were no significant differences in visual analogue scale pain scores for pinprick after 15 and 60 mm of application of ibuprofen, placebo and EM LA cream. Comparison of visual analogue scale scores for venous cannulation after similar durations of ibuprofen and EMLA creams found significantly (p < 0.014) lower scores for EMLA at 60min. We do not consider ibuprofen cream to be clinically useful for venous cannulation.
The effect of temperature upon pain during injection of propofol
Authors: Fletcher G. C. , Gillespie J. A. , Davidson J. A. H. 
Published: February 2007

SummaryPropofol has been shown to cause pain on injection. This study investigated the effect of warming propofol to 37°C on the pain of intravenous injection. One hundred and one women on outpatient gynaecology lists were allocated to receive propofol either at room temperature or at 37°C. Warming propofol decreased the incidence of pain on injection by 37% (p < 0.001), and also decreased the severity of pain reported by patients (p < 0.001). We conclude that warming propofol to 37°C provides a simple and safe method of reducing the incidence of pain on injection without the addition of other agents.
Sevoflurane degradation by soda lime in a circle breathing system
Authors: MUNDAY I. T. , WARD P. M. , FODEN N. D. , JONES R. M. , F. N. A. M. VAN PELT PhD  , KENNA J. G. 
Published: February 2007

SummarySevoflurane is degraded by soda lime to a vinyl ether commonly referred to as compound A. We measured the concentration of compound A in the circle breathing system of 31 patients receiving sevoflurane anaesthesia. fnspiratory and expiratory gas samples were analysed using gas chromatography and flame ionisation detection. The end‐tidal sevoflurane concentration and soda lime temperature were recorded. The peak compound A concentration ranged between 10 to 32ppm in the inspiratory limb and 7 to 26 ppm in the expiratory limb. There was a positive correlation between the peak compound A concentration and the end‐tidal sevoflurane concentration (r2= 0.545, p < 0.0001) and the soda lime temperature (r2= 0.301, p = 0.0014). We conclude that the end‐tidal concentration of sevoflurane and the temperature of the soda lime are important variables in determining concentration of compound A in a circle system.
The influence of three deflation techniques Optimal shape of the laryngeal mask cuff
Authors: BRIMACOMBE J. , FFARCSI A. BRAIN , BRANAGAN H. , SPRY M. , SCHOFIELD J. 
Published: February 2007

SummaryA randomised, single‐blinded, controlled trial was conducted to determine if a new laryngeal mask deflation tool offered any advantages over manual or free deflation. Ten laryngeal mask airways were tested and the deflation tool provided a significantly superior and more consistent shape than either hand manipulation or the free deflation, but did not offer any benefits in terms of residual volume. The deflator tool should encourage wider use of the standard recommended insertion technique. It can be used as a backup when manual deflation cannot provide the correct shape and may be useful for researchers studying laryngeal mask airway placement.
Contralateral pneumothorax following thoracotomy for vertebrectomy
Authors: Spears F. D. , Jardine A. 
Published: February 2007

SummaryA 21‐year‐old woman underwent correction of congenital thoracic kyphoscoliosis. The procedure was completed in two stages. The first stage involved right thoracotomy and anterior vertebrectomy. Following positional obstruction of her right‐sided chest drain she developed a very large, left‐sided pneumothorax in the immediate postoperative period. No attempt at central venous line placement had been made on the left side. Breach of the midline at vertebrectomy may allow pleural gas to cross and cause a contralateral pneumothorax.
A comparison of epidural infusions of fentanyl or pethidine with bupivacaine in the management of postoperative pain
Authors: Cox C. R. , Serpell M. G. , Bannister J. , Coventry D.M. , Williams D. R. 
Published: February 2007

SummaryA double‐blind randomised clinical trial was undertaken in 40 patients undergoing major abdominal surgery. Postoperative pain relief was provided using epidural infusions of 0.06% bupivacaine with fentanyl 4 μg.ml‐1 (n = 20) (group F) or with pethidine 1.5 mg.ml‐1 (n = 20) (group P). Postoperative pain scores using a visual analogue scale (0–100mm) were not significantly different between the two groups. Median pain scores were 0–19 mm at all times of assessment indicating that good analgesia was provided by both regimens. There was no significant difference between the epidural infusion rates in the two groups. The side effects and effect on pulmonary function were similar in each group. Nine patients were withdrawn from the study (four from group F, five from group P) due to failure of the epidural technique or other complications. Fourteen patients, equally distributed, required a total of 24 epidural‘top‐ups’by an anaesthetist because of inadequate analgesia. We demonstrated no advantage with epidural pethidine over fentanyl when used by infusion in combination with bupivacaine in the management of postoperative pain.
Oxygen saturation of patients recovering from electroconvulsive therapy
Authors: McCormick A. S. M. , Saunders D. A. 
Published: February 2007

SummaryOxygen saturation was measured by pulse oximetry in 33 psychiatric patients breathing air during recovery from 60 episodes of electroconvulsive therapy. Desaturation to less than 90% occurred in 17% of patients. Oxygen saturation values in recovery were significantly lower than pre‐operative saturations (p = 0.0014 using ANOVA), with a significant difference (p = 0.001) for up to 5min in recovery.
Mortality predicted by APACHE II
Authors: GOLDHILL D.R. , WITHINGTON P. STUART 
Published: February 2007

SummaryThe contribution of physiological values to the APACHE II score was determined by retrospective analysis of 11 348 patients undergoing intensive care. Eleven physiological variables contributed a mean of 8.9 points, 54% of the total APACHE II score. The mortality ratio (observed hospital mortality/hospital mortality predicted by APACHE II) was 1.13. We altered the APA CHE II scores and post‐intensive care hospital mortality in order to examine the effect on the mortality ratio of these changes. Increasing scores by two or four points decreased mortality ratios to 1.00 and 0.89 respectively: decreasing scores by two or four points to a minimum of zero increased mortality ratios to 1.27 and 1.44 respectively. A 25% increase or decrease in post‐intensive care hospital mortality changed mortality ratios to 1.21 and 1.05 respectively. Physiological values vary with the timing of collection and accuracy of recording. Small consistent differences in scores cause potentially important changes in the mortality ratio. Unless data collection and the effect of management before and after intensive care are standardised, using mortality ratios to compare intensive care units is likely to be inaccurate and misleading.