To evaluate the usefulness of the volumetric fluid balance for indicating and quantifying fluid absorption during transurethral resection of the prostate, 62 patients showing fluid absorption on ethanol monitoring (control method) were selected from a series of 410 operations. The volumetric fluid balance, which was measured as the difference between the input and output of irrigating fluid with and without a correction for the blood loss, proved to be an unreliable clinical tool for measuring the absorption. It indicated that fluid absorption occurred only in 40 or 18 of the 62 patients, depending on whether a correction for blood loss was made or not, the volume being only 59% and 71% (median), respectively, of that obtained by the control method. The absorption averaged 1 L in the patients in whom the volumetric measurements did not indicate absorption. The incidence of symptoms of the ‘transurethral resection syndrome’ increased with the absorbed fluid volume only when measured by the control method.

The VersaMed 201 is a lightweight, computer-controlled, electrically driven ventilator, designed for transport, home-ventilation and field use. We have evaluated the device in human beings with healthy and pathological lungs. In the first part of the study, the VersaMed was substituted for a standard operating room ventilator for 15–30 min during elective surgery in 20 subjects. In the second stage of the study, 20 patients with lung pathology who were being ventilated in the critical care department were transferred to the VersaMed for a 30-min period. In all the patients studied, arterial blood gases, haemodynamic parameters and other respiratory variables were maintained at similar values seen with the standard ventilators used. We conclude that the VersaMed 201 is suitable for use in human beings with healthy and pathological lungs as a reliable, portable ventilator.

We prospectively evaluated the effects of pneumoperitoneum and reverse Trendelenburg position on cardiopulmonary function in 20 ASA physical status II–III morbidly obese patients (body mass index > 35 kg m−2) undergoing laparoscopic gastric banding. After general anaesthesia was induced, patients' lungs were ventilated using intermittent positive pressure ventilation (at measurement times, the following parameters were used: tidal volume 12 mL kg−1 ideal body weight, respiratory rate of 12 bpm, an inspiratory to expiratory time ratio of 1 : 2). Haemodynamic variables, blood gas parameters, and lung/chest compliance were recorded: in the supine position, after induction of general anaesthesia (T0, baseline) and induction of pneumoperitoneum (T1); after placing the patient in a 25° reverse Trendelenburg position (T2); during the surgical time (T3); before deflating the abdomen (T4); after pneumoperitoneum resolution (T5), and before the end of anaesthesia, with the patient supine (T6). The PaO2, PaO2/FiO2 ratio, and lung/chest compliance decreased during the study. After the pneumoperitoneum had been resolved, lung/chest compliance but not oxygenation parameters returned to baseline values. The arterial to end-tidal CO2 tension difference progressively increased from 0.38 ± 0.3 kPa (2.85 ± 2.25 mmHg) (T0) to 0.63 ± 0.3 kPa (4.73 ± 2.25 mmHg) (T6). In morbidly obese patients, undergoing laparoscopic gastric banding, a CO2 pneumoperitoneum markedly affected gas exchange and lung/chest compliance, while positioning the patient in a 25° reverse Trendelenburg position had no beneficial effects.

This study was designed to determine whether low doses of intrathecal morphine still result in itching and it evaluates the outcome of a standardized treatment using promethazine and – for intractable itch – naloxone. Patients (n = 143) scheduled for total hip surgery were allocated to four groups (in a double blind manner) with bupivacaine 20 mg in 4 mL but different doses of intrathecal morphine: Group I, 0.025 mg, Group II, 0.05 mg, Group III, 0.1 mg and Group IV, 0.2 mg. The presence or absence of itching was noted every three hours for a 24-h period. When required, standardized treatment was provided. The incidence of itching was: Group I: 14.3%; Group II: 21.6%; Group III: 48.6%; and, Group IV: 61.7%. Itch was treated by administering promethazine intramuscularly in 2.9% (Group I); 8.1% (Group II); 10.8% (Group III), and 8.9% (Group IV), respectively. Only in group IV there was a single patient who needed naloxone to treat itching. The incidence and severity of itching is a dose-related side-effect in the dose range of 0.025–0.2 mg of intrathecal morphine. Itching still occurs after the low doses of intrathecal morphine, but symptoms vanish after promethazine 25 mg intramuscularly.

The disposition of propofol in the blood and brain of New Zealand rabbits was studied in three groups of six rabbits. One group received a single anaesthetic dose; a second group received a 1-h infusion; and a third group was studied after the rabbits were judged to have recovered from a 1-h infusion. There was a high concentration of propofol in the red blood cell fraction and in the brain, however, the red blood cell concentration largely exceeded the one found in the brain in all groups of animals. This is consistent with the high fat solubility of diisopropylphenol. The possible effects of propofol sequestered in red blood cells is discussed.

We studied a number of factors that may be associated with urinary retention, in particular the method of postoperative analgesia delivery, in 47 men and 69 women undergoing lower limb joint replacements. The following factors were studied: age, gender, height, weight, previous history of urinary retention, presence of symptoms suggestive of urinary tract obstruction, type of anaesthetic (general anaesthetic or spinal anaesthetic), type of postoperative analgesia (intramuscular or patient-controlled analgesia with morphine) and the total dose of morphine given. Urinary retention developed in 18.1% of patients. Stepwise logistic regression analysis was used to identify independent explanators of an increased probability of developing urinary retention. Three factors emerged – male gender, increasing age and the use of patient-controlled analgesia.

The inhalation of lidocaine attenuates bronchial hyper-reactivity but also causes airway irritation. However, how lidocaine dose and plasma concentration influence relationships are unknown. Accordingly, we evaluated the effects of three concentrations of lidocaine (1, 4, and 10%, total dose of 0.5, 2.0, and 5.0mg kg−1, respectively) vs. placebo in 15 mild asthmatic patients, selected by their response to a histamine challenge (decrease in FEV1 >20% to less than 18mg mL−1 of histamine [PC20]). Baseline lung function, histamine-induced bronchoconstriction, topical anaesthesia, and lidocaine plasma concentrations were obtained. FEV1 following lidocaine inhalation showed the greatest decrease for the highest dose (from 3.79 ± 0.15−3.60 ± 0.15; P=0.0012). Lidocaine inhalation increased baseline PC20 (6.1 ± 1.3mg mL−1) significantly (to 11.8 ± 3.1, 16.1 ± 3.3, and 18.3 ± 4.5mg mL−1, respectively) with no difference between the two highest doses. The duration of local anaesthesia was not significantly different between lidocaine concentrations of 4% and 10%. Thus, lidocaine inhalation, with increasing concentrations of the aerosolized solution, increases initial bronchoconstriction while significant attenuation of bronchial hyper-reactivity is not further enhanced with increasing concentrations from 4 to 10%. Plasma concentrations of lidocaine were always far below the toxic threshold. In conclusion, when local anaesthesia of the airways is required a lidocaine dose of 2.0mg kg−1 as a 4% solution can be recommended for local anaesthesia and attenuation of bronchial hyper-reactivity with the least airway irritation.

Although nonopiate analgesics may be particularly useful in the immediate postoperative period after major surgery, their use has been associated with haemodynamic adverse effects during postoperative pain treatment and in critically ill patients in intensive care. The effect of a single intravenous dose of metamizol (dipyrone) 2g, ketorolac 30mg and propacetamol 1g on haemodynamic variables and pain control in the immediate postoperative period after heart surgery is compared. Seventy-two patients undergoing elective coronary and/or heart valve surgery, were included in a cohort study of 1-years duration (1998). After weaning from mechanical ventilation and extubation, haemodynamic variables and a 4-point verbal rating pain scale were asseseed at base-line and 60 min after the administration of a single doses of metamizol, ketorolac or propacetamol. The Student's t-test for paired samples was used to compare changes produced by the study medications. A significant, but small, decrease in radial artery blood pressure was observed in all treatment groups which had little clinical relevance; no vasodilator effects were observed and ventricular function showed only minor changes: propacetamol decreased cardiac index by 10% and a 15% decrease in right ventricular work was also observed. Metamizol and ketorolac produced a 10% decrease in the left ventricular work index. Pain scores showed a statistically significant decrease in all treatment groups. The analgesic effects of metamizol, ketorolac and propacetamol were not associated with a clinically significant impairment in haemodynamic function when administered to haemodynamically stable patients.

In an attempt to overcome infections associated with central venous catheters, a new antiseptic central venous catheter coated with benzalkonium chloride on the internal and external surfaces has been developed and evaluated in a clinical trial. Patients (235) randomly received either a triple-lumen central venous catheter coated with benzalkonium chloride (117) or a polyurethane non-antiseptic catheter (118). The incidence of microbial colonization of both catheters and retained antiseptic activity of the benzalkonium chloride device following removal were determined. The benzalkonium chloride resulted in a significant reduction of the incidence of microbial colonization on both the internal and external catheter surfaces. The reduction in colonization was detected at both the intradermal (21 benzalkonium chloride catheters vs. 38 controls, P=0.0016) and distal segments of the antiseptic-coated catheters. Following catheter removal retained activity was demonstrated in benzalkonium chloride catheters which had been in place for up to 12 days. No patients developed adverse reactions to the benzalkonium chloride catheters. The findings demonstrate that the benzalkonium chloride catheter significantly reduced the incidence of catheter-associated colonization.

Postoperative renal impairment is a recognized complication of infrarenal aortic cross-clamping. Fenoldopam, a selective dopamine agonist, may increase renal blood flow and decrease tubular oxygen consumption. The objective of this study was to quantify the effects of fenoldopam (0.1 μg kg−1 min−1) on renal blood flow and renal tubular function in anaesthetized dogs that have undergone aortic cross clamping. Eight labrador dogs were selected to receive either saline or fenoldopam (0.1 μg kg−1 min−1) intravenously. Arterial pressure, heart rate, renal blood flow, urinary output, fractional excretion of sodium, creatinine clearance and lithium clearance were measured (a) prior to infusions of saline or fenoldopam (b) 1 h after commencing the infusion (c) during a 90 min period of infrarenal aortic cross-clamping with concurrent infusion of fenoldopam or saline and (d) for 1 h after simultaneous aortic declamping and discontinuation of the infusions. There was no haemodynamic instability upon commencing the infusion of fenoldopam (0.1 μg kg−1 min−1). Creatinine clearance (2.03±0.5–2.45±0.3 mL min−1 kg−1 (mean±SD)), urine output (0.23±0.16–0.35±0.23 mL min−1 (mean±SD)), and fractional excretion of sodium (0.7±0.52–1.3±0.73% (mean±SD)) increased (P < 0.05), following commencement of the fenoldopam infusion. Fractional excretion of sodium (1.2±0.7% (mean±SD)) and urine output (0.36±0.21 mL min−1 (mean±SD)) were maintained during the aortic cross-clamp period (P < 0.05). Renal blood flow increased when the fenoldopam infusion was commenced (145±43.3–161±39.2 mL min−1 (mean±SD)) and remained greater than baseline during the aortic cross-clamping period (152±44 mL min−1 (mean±SD)), although these increases did not reach statistical significance. The most striking abnormalities observed by electron microscopy were marked disruption of the microvillus brush border in proximal tubules, vacuolation and separation of epithelial cells on basolateral infolds. The changes were similar in the two groups. In conclusion fenoldopam (0.1 μg kg−1 min−1) may have renoprotective effects which persist during infrarenal aortic cross clamping.

An acute pain service (APS) was set up to improve pain management after operation. We attempted to reduce the length of stay in the intensive care unit (ICU) of patients undergoing major surgery and to improve their homeostasis and rehabilitation using a multimodal approach (pain relief, stress reduction, early extubation). Patient-controlled epidural analgesia (PCEA) was a keystone of this approach. If PCEA was not applicable, patients received patient-controlled intravenous analgesia (PCIA) instead. Brachial plexus blockade (BPB) was used for surgery of the upper limbs. A computer based documentation system was used to help evaluate prospectively (a) the quality of analgesia, (b) adverse effects and risks of the special pain management techniques, and (c) cost-effectiveness.

Patients receiving PCEA (n = 5.602) received a patient-titrated continuous infusion into the epidural space of either bupivacaine 0.175% or ropivacaine 0.2%, with 1 μg sufentanil mL−1 added, followed by patient-controlled boluses of 2 mL (lockout time 20 min). For patients receiving PCIA (n = 634) an initial bolus of 7.5–15 mg piritramide was given, and the subsequent bolus was 2 mg (lockout time 10 min). A continuous infusion of bupivacaine 0.25% was administered to patients receiving BPB (n = 113). The dose was titrated to a dynamic visual analogue scale (VAS) scores < 40.

The mean treatment periods were: BPB = 4.33 days, PCEA = 5.6 days, PCIA = 5.0 days. In the case of PCEA, the quality of pain relief, vigilance and satisfaction were superior compared with the PCIA method, which resulted in greater sedation and nausea. Although personal supervision was higher for the PCEA-treated patients, cost analysis revealed final savings of €91 620 for the year 1998 obviating the need for an ICU stay totalling 433 days.

Provided that PCEA is part of a fast-track protocol employing early tracheal extubation and optimal perioperative management, the associated initial higher costs will be recouped by the benefits to patients of better pain relief after surgery and fewer days subsequently spent in the ITU.

Arterial carbon dioxide partial pressure measurements using the NBP-75® microstream capnometer were compared with direct PaCO2 values in patients who were (a) not intubated and spontaneously breathing, and (b) patients receiving intermittent positive pressure ventilation of the lungs and endotracheal anaesthesia. Twenty ASA physical status I–III patients, undergoing general anaesthesia for orthopaedic or vascular surgery were included in a prospective crossover study. After a 20-min equilibration period following the induction of general anaesthesia, arterial blood was drawn from an indwelling radial catheter, while the end-tidal carbon dioxide partial pressure was measured at the angle between the tracheal tube and the ventilation circuit using a microstream capnometer (NBP-75®, Nellcor Puritan Bennett, Plesanton, CA, USA) with an aspiration flow rate of 30 mL min−1. Patients were extubated at the end of surgery and transferred to the postanaesthesia care unit, where end-tidal carbon dioxide was sampled through a nasal cannula (Nasal FilterLine, Nellcor, Plesanton, CA, USA) and measured using the same microstream capnometer. In each patient six measurements were performed, three during mechanical ventilation and three during spontaneous breathing. A good correlation between arterial and end-tidal carbon dioxide partial pressure was observed both during mechanical ventilation (r = 0.59; P = 0.0005) and spontaneous breathing (r = 0.41; P = 0.001); while no differences in the arterial to end-tidal carbon dioxide tension difference were observed when patients were intubated and mechanically ventilated (7.3 ± 4 mmHg; CI95: 6.3–8.4) compared to values measured during spontaneous breathing in the postanesthesia care unit, after patients had been awakened and extubated (6.5 ± 4.8 mmHg; CI95: 5.2–7.8) (P = 0.311). The mean difference between the arterial to end-tidal carbon dioxide tension gradient measured in intubated and non-intubated spontaneously breathing patients was 1 ± 6 mmHg (CI95: -11–+13). We conclude that measuring the end-tidal carbon dioxide partial pressure through a nasal cannula using the NBP-75® microstream capnometer provides an estimation of arterial carbon dioxide partial pressure similar to that provided when the same patients are intubated and mechanically ventilated.

In order to compare the effect of atropine and sodium chloride on the dynamic compliance of the respiratory system after tracheal intubation, we studied 20 patients allocated randomly into two groups to receive either: atropine after 5 min of steady state and sodium chloride after 10 min (group A) or in reverse order (group B) intravenously. The study was conducted in a randomized double-blinded manner. The patients were anaesthetized with thiopental 5 mg kg−1 followed by thiopental 50 mg intravenously, as required. Intubation was facilitated by atracurium 0.5mg kg−1 intravenously and fentanyl 200 μg intravenously. During fixed volume ventilation (100 mL kg−1, f=10), compliance and end-tidal carbon dioxide were measured every 10 s by a Datex AS/3-respiratory module connected to a portable IBM-pc. Five minutes was allowed to establish a steady state then either atropine or sodium chloride was administered according to the protocol. Respiratory dynamic compliance increased significantly after intravenous administration of atropine (P < 0.05). We conclude that atropine 1.0 mg given intravenously provides protection against an intubation-induced decline in respiratory dynamic compliance.

Dedicated nitric oxide equipped ventilators are now available commercially but are not yet common in clinical practice. With other ventilators, there is no standardized procedure for the administration or monitoring of nitric oxide. Wedescribe the use of nitric oxide in conjunction with a simple time–cycled, pressure regulated, flow generating ventilator attached to a model infant–sized lung. The measured nitric oxide concentrations were always less than calculated. Infusion site, minute ventilation and sampling port all affected nitric oxide concentration (P<0.05). Increasing minute ventilation lowered measured nitric oxide concentration exponentially. Mixing of gases improved when nitric oxide was infused closer to the ventilator. Acid contamination was found in water samples from humidifier, water trap and ventilator gas outlet. Acidification was reduced, without change in measured nitric oxide delivery, when infused prehumidifier. We recommend, when used as therapy, nitric oxide levels in inspired gases should always be measured.

Despite a plethora of findings associated with the pathophysiology of malignant hyperthermia (MH), the in vitro contracture test (IVCT) is the only reliable test for diagnosis of this heterogeneous syndrome in man. An increase of 1,4,5-IP3 (inositol 1,4,5-trisphosphate), a second messenger involved in cellular calcium homeostasis, has been observed in muscle tissue of MH susceptible (MHS) patients. The aim of this study was to evaluate if the known differences of 1,4,5-IP3 content in muscle tissue might be reproduced in mononucleated white blood cells (MWBCs). Subsequently, MWBCs of 23 healthy controls and 12 patients with a clinical suspicion for MH disposition were isolated and screened for 1,4,5-IP3 content. An IVCT according to the protocol of the European Malignant Hyperpyrexia Group (EMHG) was performed on muscle specimens of 12 patients. Eight MHN and four MHS individuals were diagnosed. Additionally, 1,4,5-IP3 synthesis in MWBCs was detected following in vitro exposure to IVCT test substances halothane (2%), caffeine (1–30 mM), and ryanodine (1–5 μM). A broad inter-individual variability of 1,4,5-IP3 content was observed in MWBCs of all volunteers, but no differences were detected between MHS and MHN individuals. These findings are in strong contrast to those observed in muscle tissue. In vitro exposure of isolated MWBCs to halothane, caffeine and ryanodine yielded no statistically significant differences between groups. A time and concentration-dependent increase in cellular 1,4,5-IP3 content could be induced in some but not all individuals of both groups. Since no correlation was obtained between induction of 1,4,5-IP3-synthesis following in vitro exposure of MWBCs to MH test substances and MH disposition, this study was terminated. We conclude from our data that the detection of 1,4,5-IP3 synthesis in MWBCs is not suitable for diagnosis of MH disposition. It remains questionable whether an altered 1,4,5-IP3 metabolism in MWBCs is involved in pathologic cascades of MH. Therefore, other cell tissues should be evaluated in further studies to clarify the role of the 1,4,5-IP3 metabolism in MH.

The Royal College of Anaesthetist requires that trainees wishing to specialise in Anaesthesia register with the College and keep a logbook documenting their experience and training in clinical anaesthesia. There are a number of advantages if such logbooks are kept in an electronic format. For the first time in the United Kingdom, we have evaluated the usefulness in a district general hospital of introducing a computerized system of record keeping based on a portable palm top computer. This has enabled the careful analysis of the individual work load of each trainee in the department by means of a specific program designed to generate a comprehensive report after the information from each individual has been downloaded on to a standard desk top computer. We have found a number of interesting and unexpected results and have highlighted ways in which the system may be improved.

In a multicentre, randomized, double-blind, placebo-controlled dose-ranging study, 1030 patients undergoing outpatient surgery with general anaesthesia received i.v. dolasetron mesylate (12.5, 25, 50, or 100 mg) or placebo. The principal outcome measure was the proportion of patients who were free of emesis or rescue medication for the 24-h period after the study drug was given; the subsidiary outcome measure was survival time without rescue medication. Effects on nausea were quantified using a visual analogue scale. Compared with placebo, a complete response was significantly higher when all four dolasetron doses were combined (49% vs. 58%, P = 0.025). In females, dolasetron, 12.5-mg, dolasetron provided maximum clinical benefit (effectiveness compared with adverse events), with no additional benefit in complete response rates or nausea visual analogue scale scores at higher doses. No significant differences were observed in complete response for any dolasetron dose in males compared with placebo. The majority of adverse events reported were mild or moderate. Dolasetron provided well-tolerated, safe, and effective prophylaxis for post-operative nausea and vomiting with maximum effectiveness observed at a dose of 12.5 mg.

We determined (a) the haemodynamic responses to intubating laryngeal mask (ILM) airway insertion/intubation and removal in anaesthetized patients, and (b) whether the timing of ILM removal influences these responses. One-hundred and twenty patients without cardiovascular disease were studied. ILM airway insertion/intubation was 5 min after induction with propofol 2mg kg−1 and maintenance of anaesthesia with sevoflurane 2% in oxygen 33% and nitrous oxide. Patients were randomly assigned for removal of the intubating laryngeal mask airway at 1, 3 and 5 min after successful intubation. Systolic and diastolic arterial pressures and heart rate were recorded preinduction (baseline), before ILM airway insertion/intubation, at 1-min intervals after insertion/intubation, and at 1-min intervals for 5 min after ILM removal. ILM insertion was successful at the Arst attempt in all patients, but 46 patients required more than one intubation attempt. Compared with baseline values, there were no increases in systolic or diastolic arterial pressure, but there was an increase in heart rate 1 min after ILM insertion/intubation (9%, P < 0.001) and 1 min after ILM removal (8%, P < 0.01). There was a significant increase in systolic and diastolic pressures and heart rate 1 min after ILM insertion/intubation (30%, 31% and 15%; all: P < 0.002) compared with before ILM insertion/intubation values and 1 min after ILM removal (9%, 8% and 7%; all P < 0.05) compared with 1 min after ILM insertion/intubation values. Removal of the ILM 1 min after successful intubation resulted in higher arterial pressure compared with removal at 3 min (systolic arterial pressure 10% higher for 1 min, P=0.01) and 5 min (systolic arterial pressure 10–23% higher for 3 min, P < 0.01; diastolic arterial pressure 10–20% higher for 4 min, P > 0.02), but there were no differences in heart rate between groups. Systolic and diastolic arterial pressures were greater if more than one intubation attempt was required. Early removal or multiple intubation attempts did not exceed baseline haemodynamic values. We conclude that ILM insertion/intubation and removal in anaesthetized patients produces little or no haemodynamic response, even if multiple intubation attempts are required. The timing of removal exerts a small, but clinically unimportant influence on these responses.

To use end-tidal PCO2 as a non-invasive estimate of arterial PCO2, one adds a nominal value, representing the arterial–end-tidal PCO2 difference. How much does one add? We hypothesized that, halving the ventilator rate and simultaneously doubling tidal volume, the immediate change in end-tidal PCO2 would be proportional to the original arterial-end-tidal PCO2 difference. We ventilated 31 patients at 20 breaths per minute (bpm), sampled arterial blood, and changed the rate to 10 bpm. The change in end-tidal PCO2 was, as hypothesized, positively correlated to the original arterial–end-tidal difference at 20 bpm (r = 0.64). End-tidal PCO2 increased in 23 patients. Thus, in theory, this method could offer some improvement in the estimate of arterial PCO2 from end-tidal. However, because of the considerable spread of values, a separate study is needed for verification

The purpose of this study was to evaluate the effects (common haemodynamic variables, peak cuff pressures, the incidence of reaction (‘bucking’) during extubation and the incidence of sore throat after operation) of lidocaine 10% instilled into the endotracheal tube cuff in intubated patients. Plasma concentrations of lidocaine were assayed. Seventy ASA class I–II patients scheduled for plastic surgery were studied. Patients were randomly divided in two groups: the cuff of the endotracheal tube was inflated with either lidocaine 10% (group L) or with saline (group S) immediately after endotracheal intubation. In group L patients, the haemodynamic changes were less (P < 0.05), and the peak cuff pressure was lower (P < 0.01) than for group S. At extubation, more patients reacted (‘bucked’) in group S (70.5% vs. 19.4%, P < 0.01). The incidence and severity of sore throat were significantly lower in group L 1 and 24-h after extubation. Plasma lidocaine concentrations did not reach toxic values. Lidocaine 10%, compared with saline, in the endotracheal tube cuff was associated with less disturbance of haemodynamic responses and less incidence of bucking during tracheal extubation. Lidocaine was also effective in reducing of incidence and severity of sore throat after operation.