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Summary Sixty ASA 1 and 2 children aged between 2 and 16 years who required tracheal intubation as part of anaesthesia for elective surgery were studied. We evaluated intubating conditions, haemodynamic responses and duration of apnoea following propofol 4 mg.kg−1 combined with either remifentanil 1.25 μg.kg−1 (group R), or suxamethonium 1 mg.kg−1 (group S). Tracheal intubation was graded as excellent, good or poor according to ease of laryngoscopy, vocal cord position, coughing, and jaw relaxation and limb movement. Thirty of group S and 28 of group R children were successfully intubated on the first attempt. Overall, intubation conditions were excellent or good in 26/30 (87%) patients in group S and 20/30 (67%) in group R (p

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.

Mycotic processes occasionally complicate atherosclerotic aortic disease and usually require aggressive surgical therapy to control sepsis and prevent arterial rupture. Rarely, fungal organisms are responsible for primary infection of the abdominal aorta. We report the first case of Cryptococcal aortitis presenting as a ruptured abdominal aortic aneurysm. The surgical, pathologic, and microbiologic aspects of fungal aortitis are discussed. (J Vasc Surg 1999;30:189-92.)

This paper describes a self-organizing fuzzy model of patients undergoing surgery which was created from 10 clinical trials with off-line analysis during maintenance of anaesthesia using the drug propofol. The effects of patient sensitivity and surgical disturbances are also represented in this patient model. Hence, this model can be considered to be a qualitative pharmacologically related model for propofol during the anaesthetic maintenance stage. Furthermore, a closed-loop simulation has been designed to validate the patient model and compare the performance of a self-organizing fuzzy logic controller algorithm against a clinically derived linguistic controller. The successful results obtained provide proof-of-concept and encouragement to perform on-line clinical trials using fuzzy logic-based monitoring and control in operating theatre in the near future.

The predictive performance of a 'Diprifusor' target controlled infusion system for propofol was examined in 46 patients undergoing major surgery, divided into three age groups (18-40, 41-55 and 56-80 years). Measured arterial propofol concentrations were compared with values calculated (predicted) by the target controlled infusion system. Performance indices (median performance error and median absolute performance error) were similar in the three age groups, with study medians of 16.2% and 24.1%, respectively. Mean values for 'divergence' and 'wobble' were -7.6%.h-1 and 21.9%, respectively. Measured concentrations tended to be higher than calculated concentrations, particularly following induction or an increase in target concentration. The mean (SD) propofol target concentration of 3.5 (0.7) micrograms.ml-1 during maintenance was lower in older patients, compared with higher target concentrations of 4.2 (0.6) and 4.3 (0.7) micrograms.ml-1 in the two younger age groups, respectively. The control of depth of anaesthesia was good in all patients and the predictive performance of the 'Diprifusor' target controlled infusion system was considered acceptable for clinical purposes.

We report a prospective randomised comparison between laparoscopic and small-incision cholecystectomy in 200 patients which was designed to eliminate bias for or against either technique.Patients were randomised in the operating theatre and anaesthetic technique and pain-control methods were standardised. Four experienced surgeons did both types of procedure. Identical wound dressings were applied in both groups so that carers could be kept blind to the type of operation.There was no significant difference between the groups for age, sex, body mass index, and American Society of Anaesthesiologists grade. Laparoscopic cholecystectomy took significantly longer than small-incision cholecystectomy (median 65 [range 27-140] min vs 40 [18-142] min, p0.001). The operating time included operative cholangiography which was attempted in all patients. We found no significant difference between the groups for hospital stay (postoperative nights in hospital, median 3-0 [1-17] nights for laparoscopic vs 3-0 [1-14] nights for small-incision, p=0.74), time back to work for employed persons (median 5-0 weeks vs 4.0 weeks; p=0.39), and time to full activity (median 3-0 weeks vs 3.0 weeks; p=0.15).Laparoscopic cholecystectomy takes longer to do than small-incision cholecystectomy and does not have any significant advantages in terms of hospital stay or postoperative recovery.

A hierarchical structure, based on fuzzy modelling, which can monitor depth of anaesthesia (DOA) from many clinical signs in the operating theatre, is described. The first level uses numerical clinical signs, such as systolic arterial pressure (SAP) and heart rate (HR), via a rule-base from anaesthetists' experience or a self-organizing learning algorithm to interpret primary depth of anaesthesia (PDOA). The second level is focused on non-numerical clinical signs, such as sweating (SW), lacrimation (LA) and pupil response (PR), which can be merged with the first level of PDOA to decide DOA with more confidence. Furthermore, linguistic rules and a simple fuzzy modelling concept have been used to model a patient during induction and maintenance stages. Not only can this model simulate new ideas and monitoring methods, but it can also be used clinically on-line to give an estimate of the adequacy of DOA. Successful results have given confidence to perform on-line clinical trials in the operating theatre. Two configurations of fuzzy modelling to determine the rule-base are described in this paper. Firstly, a self-organizing fuzzy modelling approach has the ability to generate rules on-line from input and output data. Secondly, if there is no direct measurement for the system output or it is very difficult to interpret, a self-organizing learning system which can learn rules from off-line input and output data can be utilized for modelling such systems.

Changes in-intra-ocular pressure during spontaneous ventilation with a laryngeal mask were compared with controlled ventilation using a tracheal tube in 40 patients undergoing intra-ocular surgery under general anaesthesia. Intra-ocular pressure was measured before induction, after establishing the airway, at the end of the operation and after removal of the airway device. Anaesthesia was induced with propofol and maintained with enflurane and nitrous oxide in oxygen. Mean end-tidal carbon dioxide tension was significantly higher during spontaneous ventilation than during controlled ventilation 5 min after establishing the airway (5.7 versus 4.5) and at the end of surgery (6.1 versus 4.2) (p < 0.001). Despite this, intra-ocular pressures were lower than baseline and similar in the two groups throughout anaesthesia. At the end of surgery, intra-ocular pressure (mmHg) was 11.2 and 8.6 during spontaneous or controlled ventilation respectively. One min after removal of the device, mean intra-ocular pressure (mmHg) in the tracheal tube group (16.0) was slightly higher than baseline (15.3) and was significantly higher than the laryngeal mask group (10.9) (p < 0.01). Spontaneous ventilation with a laryngeal mask is an acceptable alternative to controlled ventilation with tracheal intubation in elective intra-ocular surgery.

A 65-year-old man developed massive hemoperitoneum secondary to spontaneous splenic rupture. Histopathological analysis of the spleen demonstrated necrotizing granulomas. Results of serological tests indicated infection with a species of Bartonella, and immunohistochemical staining established Bartonella henselae as the cause of splenitis. To our knowledge, this represents the first reported case of spontaneous splenic rupture caused by infection with a species of Bartonella.

Summary A new system for sampling from arterial cannulae has been designed which avoids the need to aspirate flushing solution before taking a sample and limits blood loss. The new system was compared with a standard sampling system and direct arterial sampling using in vitro models. A series of haemoglobin concentrations wen- prepared and sampled using the three sampling methods. There were no clinically significant differences in the values obtained with the different sampling techniques.

A machine-learning rule-based fuzzy logic controller for depth of anaesthesia which is similar to the way an anaesthetist works is presented in this paper. The results of discussions with anaesthetists to obtain a rule base and the application of fuzzy logic to predict the primary depth of anaesthesia (PDOA) and to control drug administration are very promising. By using simple rules from machine learning trials, similar results for the prediction of PDOA were obtained and can be used to design a drug infusion controller. The robustness of the self-organising fuzzy logic control (SOFLC) algorithm is good and can supplement the anaesthetist's experience for administering drug to patients when the system is dynamic and time-varying. Using these results, the design of a hierarchical architecture for the determination of the level of depth of anaesthesia is being investigated, which will include the use of clinical signs and refinements in the control of drug administered to patients.< >

Summary A double-blind trial of the effect of droperidol on the incidence of nausea and vomiting in patients using patient-controlled analgesia was carried out in 60 healthy women undergoing abdominal hysterectomy. After a standard anaesthetic including droperidol 2.5 mg as a prophylactic antiemetic, patients were randomly allocated to receive postoperative patient-controlled analgesia with either morphine alone (2mg.ml−1) or morphine (2mg.ml−1) with droperidol (0.2 mg.ml−1) added to the syringe. Verbal scores and visual analogue scores for nausea, vomiting, pain and sedation were made at 4, 12 and 24 h postoperatively, and any requirement for intramuscular prochlorperazine noted. There was no difference between the groups at any time in the amount of morphine consumed or in pain scores. At 12 h, patients receiving droperidol experienced significantly less nausea, and over the first 24 h, 31% required prochlorperazine compared with 59.3% of patients not receiving droperidol. The number of patients with sedation at 24 h was significantly greater in the droperidol group. We conclude that the addition of droperidol to morphine both reduces nausea and the need for further antiemetic treatment.

The value of using a combined infusion of morphine with a variable dose of ketamine for postoperative analgesia following upper abdominal surgery was assessed in a double-blind randomised study of 40 elderly patients. Four groups of 10 patients received an infusion of morphine at 1 mg.h-1, either alone, or combined with ketamine at a rate of 5, 10 or 20 mg.h-1. The addition of ketamine to a continuous infusion of morphine did not significantly improve either analgesia or postoperative lung function. Increasing the dose of ketamine resulted in an increased incidence of postoperative dreaming (p < 0.01).

The Ohmeda 9000 syringe pump was developed in response to the need for an infusion apparatus to administer intravenous anaesthetic agents. It incorporates a bolus facility for the rapid, controlled delivery of loading infusions, or incremental dosing over a background maintenance infusion, and may be interfaced with a controller for computer-driven infusions. The Ohmeda 9000 pump has undergone bench testing and detailed evaluation in clinical practice using a variety of syringe sizes and makes. It is capable of accurate delivery over a range of infusion rates provided the recommended manufacturers' syringes are used with the appropriate pump setting. The pump was easy to use and reliable in clinical research and routine clinical practice. It should find its niche as the first genuinely 'anaesthetist-friendly' infusion pump.

EDITOR,—D W Ryan1 and J Bion,2 in discussing the provision of intensive care beds, suggest that there should be more high dependency beds, although information on their effectiveness seems to be lacking. At the Royal Hallamshire Hospital we opened a two bedded, five day high dependency unit in 1992. The primary reason for this was to counter the recurrent cancellation of elective major surgery when an intensive care bed …

Dental disorders have been recognized as major sources of infection in patients with hematologic malignancies (HM). Management of severe dental infections usually includes dental extractions (DE), but the safety of extractions in patients with HM who are at risk for bleeding, sepsis, and poor wound healing has not been well established. In conjunction with an aggressive program of dental care, 142 DE were performed in 26 patients with acute leukemia, myelodysplastic syndromes, and myeloproliferative disorders. Granulocytopenia (less than 1,000 granulocytes/microL) was present during or within ten days following surgery in 14 patients. In these 14 patients (101 DE), the mean granulocyte count was less than 450/microL, with a median duration of granulocytopenia following surgery of 32 days (range, four to 169 days). Thrombocytopenia (less than 100,000 platelets/microL) occurred during or within two days following surgery in 13 patients (80 DE), with a mean platelet count of 63,500/microL. Transfusions were given for platelet counts less than 50,000/microL. All DE were performed without significant complications. Bleeding was minor to moderate and easily controlled with local measures; no patient required transfusion due to hemorrhage. Average maximum temperature 24 hours after DE was 37.7 degrees C. No episodes of bacteremia were documented within ten days of DE. Minor delay in wound healing was observed in two patients. We conclude that DE can be safely performed in patients with HM in combination with aggressive supportive care.

Summary In clinical trials, the diagnostic utility of a radioimmunoassay (RIA) to detect Aspergillus antigen was demonstrated in sera obtained from patients with invasive pulmonary, endothelial, and disseminated aspergillosis, in cerebrospinal fluids from patients with Aspergillus meningoencephalitis, and in bronchoalveolar lavage fluids from patients with invasive pulmonary aspergillosis. The RIA was further evaluated in three blinded, controlled clinical trials. In one, sera were collected prospectively from patients with acute leukemia. Antigenemia was detected in four patients with invasive pulmonary aspergillosis (IPA) due to A. flavus , appeared early in the course of infection of three patients concurrent with the onset and evolution of lung infiltrates, and remitted with antifungal chemotherapy. Antigenemia was not detected in three patients before the onset of IPA, in eight leukemic controls, or in the 24 normals. In contrast, seven bronchoscopies were performed in five patients with IPA; fungi were not isolated in three. In a second study, antigenemia was found in coded sera from two patients with invasive aspergillosis but not in eight controls. In the third controlled study, 616 sera from 79 hematology patients admitted on 152 occasions were analyzed for circulating fungal antigen. The diagnostic utility of the RIA was confirmed and levels of antigenemia correlated with the patients' clinical course. These studies demonstrate the utility of the Aspergillus antigen RIA for diagnosis of invasive aspergillosis in hospitalized high risk patients.

A 57 year old white man with aortic insufficiency and previously undiagnosed ankylosing spondylitis, who developed subacute bacterial endocarditis (SBE), is described. Emergency aortic valve replacement was necessary, and the aortic valve pathology showed diffusely fibrosed and thickened valve leaflets with bacterial vegetations. This is the first recorded case of SBE in ankylosing spondylitis.

There are few data in the literature that describe the use of remifentanil when administered as a component of an inhalation or total i.v. anaesthetic (TIVA) technique. We studied 251 male and female patients, aged 18-75 years, ASA I-II, undergoing inguinal hernia repair, arthroscopic knee surgery or varicose vein surgery of at least 30 min duration without premedication. Patients were randomized to receive a remifentanil loading dose of 1.0 microgram kg-1 followed by a continuous infusion of 0.5 microgram kg-1 min-1 in combination with isoflurane (end-tidal concentration 0.6%), (Group I, n = 115) or propofol (initial infusion rate 9 mg kg-1 h-1 reduced to 6 mg kg-1 h-1 after 10 min), (Group P, n = 118). The remifentanil infusion rate was reduced by 50%, 5 min after tracheal intubation. Intraoperative stresses were treated with a remifentanil bolus (1 microgram kg-1) followed by an increase in the remifentanil infusion rate. At the insertion of the last suture, the remifentanil infusion and concomitant anaesthetic were switched off simultaneously. Times to spontaneous respiration, adequate respiration and tracheal extubation were significantly shorter in group I compared with group P (6.4 min vs 7.6 min, P < 0.01; 7.6 min vs 9.3, P < 0.003; 7.8 min vs 9.5 min, P < 0.015). Overall mean systolic blood pressures during surgery were greater in group P compared with group I (P < 0.05) but the absolute differences were clinically insignificant (4-5 mm Hg).