Surface behavior of amphiphiles in aqueous solution: a comparison between different pentanol isomers

Molecular-level understanding of concentration-dependent changes in the surface structure of different amphiphilic isomers at the water–vapor interface was gained by molecular dynamics (MD) simulation and X-ray photoelectron spectroscopy (XPS).

Reducing delirium in elderly patients with hip fracture: a multi-factorial intervention study

BACKGROUND

There is an evident need for improved management of elderly patients with trauma in order to avoid common and troublesome complications such as delirium. The aim of this study was to investigate whether an implementation of a multi-factorial program including intensified pre-hospital and perioperative treatment and care could reduce the incidence of delirium in elderly patients with hip fracture, cognitively intact at admission to the hospital. In addition, we explored the factors that characterize patients who developed delirium.

METHODS

A prospective, quasi-experimental design was used. A total of 263 patients with hip fracture (> or = 65 years), cognitively intact at admission, were consecutively included between April 2003 and April 2004. On 1 October 2003, a new program was introduced. All patients were screened for cognitive impairment within 30 min after admission to the emergency department using The Short Portable Mental Status Questionnaire (SPMSQ). To screen for delirium, patients were tested within 4 h of admission and thereafter daily, using the Organic Brain Syndrome scale.

RESULTS

The number of patients who developed delirium during hospitalization was 74 (28.1%), with a decrease from 34% (45 of 132) in the control group to 22% (29 of 131) in the intervention group (P=0.031). Patients who developed delirium were statistically older, more often had > 4 prescribed drugs at admission and scored less well in the SPMSQ test.

CONCLUSION

The use of a multi-factorial intervention program in elderly hip fracture patients, lucid at admission, reduced the incidence of delirium during hospitalization by 35%.

Light vs. heavy sedation during mechanical ventilation after oesophagectomy--a pilot experimental study focusing on memory

BACKGROUND

To assess and compare the feasibility and stressful memories of light vs. heavy sedation during post-operative mechanical ventilation.

METHODS

Randomized clinical trial in one general intensive care unit (ICU) in a Swedish university hospital. Thirty-six adults were randomly assigned to receive either light [Motor Activity Assessment Scale (MAAS) 3-4] or heavy (MAAS 1-2) sedation with continuous i.v. infusion of propofol during post-operative invasive mechanical ventilation after oesophagectomy. The patients were interviewed at the general ward 5 days post-ICU using the ICU Memory Tool and the ICU Stressful Experience Questionnaire, and 2 months post-ICU using the Impact of Event Scale Revised. Patient data and hourly recorded MAAS values were collected after the interviews.

RESULTS

Seventy-four per cent of the 139 MAAS values in the light sedation group (n=18) and 79% of the 142 in the heavy sedation group (n=18) were within the targeted levels, and the median MAAS scores were 3.0 vs. 1.25, respectively. Intention-to-treat analyses showed no significant difference in the prevalence of stressful memories between groups, including endotracheal tube discomfort, presenting wide 95% confidence intervals for the difference in outcome estimates. Excluding the patients with a prolonged ICU stay (n=3), a higher prevalence of delusional memories was found in the heavy sedation group (31% vs. 0%, P=0.04).

CONCLUSIONS

This small randomized-controlled pilot study suggests that a light sedation regimen during short-term post-operative mechanical ventilation after major surgery is feasible without increasing patient discomfort.

Stressful memories and psychological distress in adult mechanically ventilated intensive care patients - a 2-month follow-up study

AIM

To investigate patients' psychological distress in relation to memory and stressful experiences in the intensive care unit (ICU), and to identify early predictors for the development of high levels of acute post-traumatic stress disorder (PTSD)-related symptoms.

METHODS

A prospective cohort study was performed over 18 months in two general ICUs, including 313 intubated mechanically ventilated adults admitted for more than 24 h, 226 of whom completed the study. Patients were interviewed 5 days and 2 months post-ICU concerning their memories and psychological distress. The instruments used were the ICU Memory Tool, ICU Stressful Experience Questionnaire, Hospital Anxiety and Depression Scale and Impact of Event Scale-Revised (IES-R).

RESULTS

High symptom levels of anxiety, depression and acute PTSD 2 months post-ICU were present in 4.9%, 7.5% and 8.4% of the 226 patients, respectively. Psychological distress 2 months post-ICU was associated with experiences of the ICU rated as extremely stressful and with high levels of anxiety and depression 5 days post-ICU, but not with amnesia or delusional memories without factual recall of the ICU. Female sex, signs of agitation (increasing proportion of Motor Activity Assessment Scale scores of 4-6) and feelings of extreme fear during the ICU stay were significantly and independently associated with IES-R scores of 30 or more.

CONCLUSIONS

Extremely stressful experiences of the ICU are associated with subsequent psychological distress. Female sex, agitation and extreme fear during the ICU stay seem to increase the risk of developing high levels of acute PTSD-related symptoms.

Studies on dodecyl betainate in combination with its degradation products or with phosphatidyl choline–phase behavior and hemolytic activity

Surface active betaine esters contain a hydrolysable bond and give naturally occurring products (fatty alcohol and the amino acid betaine) on degradation. They are therefore interesting candidates for use as cationic surfactants in pharmaceutical applications. In this work the phase behavior of two systems of relevance for the utilization of dodecyl betainate as a pharmaceutical excipient is studied, namely dodecyl betainate/dodecanol/betaine hydrochloride/D2O and dodecyl betainate/phosphatidyl choline (PC)/ethanol/D2O. The techniques used for phase characterisation were 2H NMR measured on the solvent, small angle X-ray spectroscopy and optical microscopy. Dilute dodecyl betainate/PC dispersions were characterized using laser diffraction. It is shown that introduction of relatively small amounts of the hydrolysis products of dodecyl betainate, i.e., dodecanol and betaine (used in the form of betaine hydrochloride), has a strong effect on the phase behavior of the binary dodecyl betainate/D2O system. The degradation products change the average curvature of the surfactant film so that, instead of a hexagonal phase at concentrations above the micellar phase, a probably defective, lamellar phase seems to form. The dodecyl betainate/PC/ethanol/D2O system shows a large region of a highly swelling lamellar phase. Dispersions of dodecyl betainate/PC/ethanol in water can be prepared with low energy input; i.e., the preconcentrate can be regarded as a self-dispersing solution. Introduction of dodecyl betainate and its degradation products does not impair the ability of PC to form vesicles. Experiments for evaluating the toxicity of surface active betaine esters to erythrocytes were also performed. There are indications that the hemolytic activity of dodecyl betainate is lower than that of the stable surfactant tetradecyltrimethylammonium chloride, which has similar critical micelle concentration. A combination of dodecyl betainate and PC gives very low hemolytic activity.

Cancer patients' experiences of care related to pain management before and after palliative care referral

Pain is the main problem for patients with cancer referred to palliative care (PC). Pain management in PC requires a multidimensional approach. A questionnaire was used to determine cancer patients' experiences of care related to pain management, before and after being referred to PC, and to also discover possible correlations between pain control and other aspects of care. Seventy-five consecutive patients from two PC teams were included in the study. The patients had experienced a statistically significant (P < 0.01) improvement in care after being referred to PC, despite the fact that pain control had not been optimized. Patients' description of 'pain control' after being referred to PC had a statistically significant correlation with their 'feeling of security' and 'continuity of care' throughout the same period. The conclusion is that care provided in PC is vital to successful pain management. Pain control depends not only on analgesics but also on many other aspects of care provided by the nurse. Continuity of care and the opportunity to talk increases the patients' feeling of security, which is also of utmost importance to successful pain management.

Abolished circadian rhythm of melatonin secretion in sedated and artificially ventilated intensive care patients

BACKGROUND

Sleep disturbance is common in intensive care patients. Aside from its unpleasantness, there is a correlation with intensive care unit (ICU) syndrome/delirium. Reasons for sleep deprivation appear to be multifactorial, including the underlying illness, an acute superimposed disturbance, medications, and the ICU environment itself. There are reasons to believe that alterations of the 'biological clock' might contribute. Melatonin secretion is one reflection of this internal sleep/wake mechanism. Melatonin levels are normally high during the night and low during daytime, being suppressed by bright light.

METHODS

Melatonin levels in blood and urine were studied over 3 consecutive days in eight critically ill patients during deep sedation and mechanical ventilation. Sedation was assessed with the sedation-agitation (SAS) scale and bispectral index (BIS) monitor.

RESULTS

The circadian rhythm of melatonin release was abolished in all but one patient, who recovered much more quickly than the others. There was no correlation between melatonin levels and levels of sedation.

CONCLUSIONS

This study indicates that dyssynchronization of the melatonin secretion rhythm is common in critically ill and mechanically ventilated patients. It could be hypothesized that an impairment of the melatonin rhythm may play a role in the development of sleep disturbances and delirium in intensive care patients, and that melatonin supply could reduce the incidence of these phenomena.

The effect of heat and moisture exchanger on humidity and body temperature in a low-flow anaesthesia system

BACKGROUND

Artificial humidification of dry inspired gases seems to reduce the drop in body temperature during surgery. The aim of this study was to evaluate the humidity and temperature of anaesthetic gases with heat and moisture exchangers (HMEs). The secondary aim was to evaluate if HMEs in combination with low-flow anaesthesia could prevent a decrease in the body temperature during general anaesthesia.

METHODS

Ninety patients scheduled for general surgery were randomised to receive a fresh gas flow of 1.0, 3.0 or 6.0 l min-1 with or without HMEs in a circle anaesthesia system. Relative humidity, absolute humidity, temperature of inspired gases and body temperatures were measured during 120 min of anaesthesia.

RESULTS

The inspiratory absolute humidity levels with HMEs were 32.7 +/- 3.1, 32.1 +/- 1.1 and 29.2 +/- 1.9 mg H2O l(-1) and 26.6 +/- 2.3, 22.6 +/- 3.0 and 13.0 +/- 2.6 mg H2O l(-1) without HMEs after 120 min of anaesthesia with 1.0, 3.0, or 6.0 l min(-1) fresh gas flows (P < 0.05, between with and without HME). The relative humidity levels with HMEs were 93.8 +/- 3.3, 92.7 +/- 2.2 and 90.7 +/- 3.5%, and without the HMEs 95.2 +/- 4.5, 86.8 +/- 8.0 and 52.8 +/- 9.8% (P < 0.05, between with and without HMEs in the 3.0 and 6.0 l min(-1) groups). The inspiratory gas temperatures with HMEs were 32.5 +/- 2.0, 32.4 +/- 0.5 and 31.0 +/- 1.9 degrees C, and 28.4 +/- 1.5, 27.1 +/- 0.8 and 26.1 +/- 0.6 degrees C without HMEs after 120 min of anaesthesia (P < 0.05, between with and without HME). The tympanic membrane temperatures at 120 min of anaesthesia were 35.8 +/- 0.6, 35.5 +/- 0.6 and 35.4 +/- 0.8 degrees C in the groups with HMEs, and 35.8 +/- 0.6, 35.3 +/- 0.7 and 35.3 +/- 0.9 degrees C in the groups without the HMEs (NS).

CONCLUSIONS

The HMEs improved the inspiratory absolute humidity, relative humidity and temperature of the anaesthetic gases during different fresh gas flows. However, the HMEs were not able to prevent a body temperature drop during low-flow anaesthesia.

Low-flow anaesthesia with desflurane: kinetics during clinical procedures

BACKGROUND AND OBJECTIVE

Low-flow anaesthesia is economical and less polluting. The purpose of this study was to determine the inspired and end-tidal desflurane concentrations during anaesthesia with a vaporizer setting maintained at 5%, during low-flow anaesthesia after 120 min with fresh gas inflows of 1.0 and 2.0 L min-1.

METHODS

The study was both prospective and randomized, including 56 patients (28 patients in each group) scheduled for elective surgery of an expected anaesthesia time of at least 120 min. Inspired and end-tidal concentrations of desflurane were measured during low-flow anaesthesia with fresh gas inflows of 1.0 and 2.0 L min-1. The vaporizer setting was fixed at 5% desflurane.

RESULTS

The inspired and end-tidal concentrations of desflurane in the 1.0 L min-1 group after 120 min were 4.54% vs. 4.37% (P < 0.001). In the 2.0 L min-1 group, the inspired and end-tidal concentrations of desflurane were 4.76% vs. 4.58% (P < 0.001). The estimated end-tidal/inspired ratios at 120 min of anaesthesia were 0.96 in both groups. At a fresh gas flow of 1.0 L min-1, the end-tidal concentration was 0.87 of the vaporizer setting. Increasing the fresh gas flow to 2.0 L min-1 increased the end-tidal value by 0.05.

CONCLUSION

There is a significant difference between the inspired and end-tidal concentrations of desflurane when fresh gas inflows were 1.0 and 2.0 L min-1, but not for the ratio of inspired/end-tidal.

Clinical signs of ICU syndrome/delirium: an observational study

Some clinical signs of the intensive care unit (ICU) syndrome/delirium are probably known, but there may be additional signs that can be observed during the care of ICU patients. The aim of this study was to investigate and describe the clinical signs of the ICU syndrome in relation to patients' reactions and behaviour following the second day of their stay in an ICU. A total of 31 patients were observed during the weaning process and in the days following extubation. Informal dialogues between the patient and the observer, using parts of the questionnaire 'Organic Brain Syndrome Scale' were also carried out. The data was structured in a chronological order and consists of descriptions of patients' behaviour and reactions, together with events, occurrences and environmental circumstances. It was found that the patients showed a great variety of clinical signs that could be related to the ICU syndrome. Such signs were the quality, ability and divergence of speech; talking, movements, bodily position and facial expressions. Several patients also related unreal experiences only occasionally, while others experienced them during longer periods. The clinical signs did not seem to be separate phenomena but were inter-connected and part of a progression, and, therefore must be seen in the overall context and situation. Longer periods of observation and repeated interaction with patients are necessary in order to be aware of onset and clinical signs of the ICU syndrome.

Nonpeptide tachykinin receptor antagonists. II. Pharmacological and pharmacokinetic profile of SB-222200, a central nervous system penetrant, potent and selective NK-3 receptor antagonist

The pharmacological and pharmacokinetic profile of SB-222200 [(S)-(-)-N-(alpha-ethylbenzyl)-3-methyl-2-phenylquinoline-4-car boxami de], a human NK-3 receptor (hNK-3R) antagonist, was determined. SB-222200 inhibited (125)I-[MePhe(7)]neurokinin B (NKB) binding to Chinese hamster ovary (CHO) cell membranes stably expressing the hNK-3 receptor (CHO-hNK-3R) with a K(i) = 4.4 nM and antagonized NKB-induced Ca(2+) mobilization in HEK 293 cells stably expressing the hNK-3 receptor (HEK 293-hNK-3R) with an IC(50) = 18.4 nM. SB-222200 was selective for hNK-3 receptors compared with hNK-1 (K(i) > 100,000 nM) and hNK-2 receptors (K(i) = 250 nM). In HEK 293 cells transiently expressing murine NK-3 receptors (HEK 293-mNK-3R), SB-222200 inhibited binding of (125)I-[MePhe(7)]NKB (K(i) = 174 nM) and antagonized NKB (1 nM)-induced calcium mobilization (IC(50) = 265 nM). In mice oral administration of SB-222200 produced dose-dependent inhibition of behavioral responses induced by i.p. or intracerebral ventricular administration of the NK-3 receptor-selective agonist, senktide, with ED(50) values of approximately 5 mg/kg. SB-222200 effectively crossed the blood-brain barrier in the mouse and rat. The inhibitory effect of SB-222200 against senktide-induced behavioral responses in the mouse correlated significantly with brain, but not plasma, concentrations of the compound. Pharmacokinetic evaluation of SB-222200 in rat after oral administration (8 mg/kg) indicated sustained plasma concentrations (C(max) = about 400 ng/ml) and bioavailability of 46%. The preclinical profile of SB-222200, demonstrating high affinity, selectivity, reversibility, oral activity, and central nervous system penetration, suggests that it will be a useful tool compound to define the physiological and pathophysiological roles of NK-3 receptors, in particular in the central nervous system.

Preclinical pharmacokinetics and interspecies scaling of a novel vitronectin receptor antagonist

Allometric scaling may be used in drug development to predict the pharmacokinetics of xenobiotics in humans from animal data. Although allometry may be successful for compounds that are excreted unchanged or that are oxidatively metabolized (with corrections for metabolic capacity), it has been more challenging for compounds excreted primarily as conjugates in bile. (S)-10, 11-Dihydro-3-[3-(pyridin-2-ylamino)-1-propyloxy]-5H-dibenzo[ a, d]cycloheptene-10-acetic acid (SB-265123) is a novel alphavbeta3 ("vitronectin receptor") antagonist. In this study, the in vivo pharmacokinetics and in vitro plasma protein binding of SB-265123 were examined in four species: mice, rats, dogs, and monkeys. In monkeys and dogs, SB-265123 exhibited moderate clearance, whereas low clearance (<20% hepatic blood flow) was observed in the rat, and high clearance (>70% hepatic blood flow) was seen in the mouse. The concentration-time profiles indicated the possibility of enterohepatic recirculation; subsequent studies in bile duct-cannulated rats demonstrated extensive biliary excretion of an acyl-glucuronide of SB-265123. In allometric scaling to predict the disposition of SB-265123 in humans, various standard correction factors were applied, including protein binding, maximum lifespan potential, and brain weight; each failed to produce adequate interspecies scaling of clearance (r(2) < 0.72). Consequently, a novel correction factor incorporating bile flow and microsomal UDP-glucuronosyltransferase activity in each species was applied, demonstrating substantial improvement in the correlation of the allometric plot (r(2) = 0.96). This study demonstrates a novel allometric correction that may be applicable to compounds that undergo conjugation and biliary excretion.

Acute confusion and unreal experiences in intensive care patients in relation to the ICU syndrome. Part II

The intensive care unit syndrome (ICU syndrome) is defined as an altered emotional state occurring in a highly stressful environment, which may manifest itself in various forms such as delirium, confusion, crazy dreams or unreal experiences. The purpose of this part of a study of patients' experiences is to describe and illuminate patients' experiences of acute confusion, disorientation, wakefulness, dreams and nightmares during and after their stay in the ICU. The data were obtained from 19 ventilated patients, who were interviewed twice and had stayed at least 36 hours in the ICU, the first interview being about one week after discharge from the ICU, and the second 4-8 weeks later. The hermeneutic approach used when interpreting and analysing the text from the interviews revealed that patients' experiences of unreal experiences were often associated with intense fear. Intense or continuous unbearable fear seems to result in frightening unreal experiences, which further increase the level of fear. Care actions or caring relationships with relatives or nurses can reduce this fear, which can help to prevent the occurrence and/or duration and intensity of the unreal experiences. Trust and confidence in nurses or significant others and feelings of self-control or trust in self-control seemed to reduce the risk of unreal experiences so that adverse stimuli might only trigger a mild confusion.

Patients' experience of being critically ill or severely injured and cared for in an intensive care unit in relation to the ICU syndrome. Part I

The intensive care unit (ICU) syndrome is regarded principally as a complex interaction of several contributory factors, all of which can be seen as partly responsible for the development of the syndrome. The purpose of this study was to describe and give a deeper insight into patients' experiences and memory recall, both during and after their stay in the ICU. Nineteen patients who had been respirator treated (ventilated), and had stayed at least 36 hours in the ICU, were interviewed about one week after discharge, and again 4-8 weeks after their discharge from the ICU. Patients' experiences are interpreted and related to previous views held concerning the syndrome, together with an awareness of other important and significant phenomena, i.e. a hermeneutic approach. This study partly confirms the findings of earlier studies concerning the ICU syndrome, but also reveals some new aspects, which have not previously been considered. The patients described themselves as experiencing some sort of state of chaos following the onset of their sickness, injury or accident, which resulted in feelings of extreme instability, vulnerability and fear, often experienced as prolonged inner tension. It was reported that even the most trivial events in circumstances or routines could trigger changes-either an increase or decrease-in patients' feelings of fear or inner tension. The caring relationship was perceived as providing an important degree of security and comfort. Nursing care actions can therefore be seen as vital factors in patients overcoming the accompanying horrific experiences to which they can be subjected. This state of chaotic feeling, and how it is combated and treated, appear to be one critical factor in the development and progression of the ICU syndrome.

Coronary stenting for coronary artery disease in a cardiac transplant recipient

Accelerated coronary artery disease in the transplanted heart remains the leading cause of death in heart transplant recipients. Traditional treatment modalities have generally yielded sub-optimal results. Coronary artery stents are used frequently in the non-transplanted heart to treat coronary artery disease. Only a few cases using this approach in the cardiac transplant recipient have been reported. This report details the use of this modality in a transplant recipient with significant two-vessel coronary artery disease 11 years after orthotopic cardiac transplantation.

Pharmacokinetics of intravenously and orally administered eprosartan in healthy males: absolute bioavailability and effect of food

Eighteen healthy males received a single 300 mg oral dose of eprosartan as the commercial wet granulation formulation under fasting conditions and following a high-fat breakfast and a single 20 mg intravenous (i.v.) dose. The pharmacokinetics of i.v. eprosartan (mean +/- S.D.) were characterized by a low systemic plasma clearance (131.8 +/- 36.2 mL min(-1)) and a small steady-state volume of distribution (12.6 +/- 2.6 L). Oral bioavailability averaged 13.1%, due to incomplete absorption. In vitro dynamic flow cell dissolution data showed that pH-dependent aqueous solubility of eprosartan is one factor which limits absorption. Eprosartan terminal half-life was shorter after i.v. (approximately 2 h) versus oral (approximately 5-7 h) administration, which may be due to detection of an additional elimination phase or absorption rate-limited elimination following oral administration. Oral administration of eprosartan following a high-fat meal compared with fasting conditions resulted in a similar extent of absorption (based on AUC), but a decreased absorption rate. Cmax was approximately 25% lower, and a median delay of 1.25 h in time to Cmax was observed when eprosartan was administered with food. These minor changes in exposure are unlikely to be of clinical consequence; therefore, eprosartan may be administered without regard to meal times.

Decisions not to resuscitate in a Swedish university hospital

BACKGROUND

Cardiopulmonary resuscitation (CPR) has the potential to save many lives. Used indiscriminately though, it may be harmful and not in the best interest of the patient. An advance directive to refrain from resuscitation in selected patients is probably not uncommon in Sweden, but guidelines ruling this are still generally lacking. This study was performed to evaluate the use and documentation of do-not-resuscitate orders in a Swedish university hospital.

METHODS

Adult inpatients at 7 medical, 3 surgical and 2 neurological wards, a total of 220, were investigated on one specific day by interviewing the physicians and nurses responsible for their care.

RESULTS

We found a discrepancy in doctors' and nurses' perception concerning the appropriateness of CPR in selected patients. CPR was judged by doctors to be inappropriate for 45 patients (20%). Out of these 45 patients, only 24 had a written do-not-resuscitate order in their medical record, in most cases noted as a code word or sign only. Rarely were the patient or his/her relatives involved in the decision-making process.

CONCLUSION

We conclude that a decision to refrain from resuscitation is often not made, even when considered medically and ethically justifiable. Also, the use of coded information as a sole indicator for a patient not to be resuscitated is still common practice. The patient or his/her relatives are rarely involved in this decision.

Disposable CO2-detector, a reliable tool for determination of correct tracheal tube position during resuscitation of a neonate

Undetected displacement of the endotracheal tube may lead to death of the patient. The present report illustrates the benefits of using a disposable carbon dioxide detector, designed for adults, also in a new-nate during resuscitation. The infant had asystole after delivery by caesarean section. The trachea was intubated, but the tube was displaced soon after return of spontaneous circulation. The oesophageal position of the tube was, however, discovered before bradycardia had occurred, thanks to the use of the CO2 detector.

Intensive care syndrome: a literature review

The aim in this literature review is to describe the definitions, denominations, clinical signs and symptoms, explanations, causative factors and interrelationships of the intensive care syndrome discussed since 1950. It was found that there is no agreement about which symptoms should be included in the syndrome, when the syndrome may appear and how many patients may be affected. Furthermore, it is unclear what causes the development of the syndrome; most authors conclude that there are many reasons for it. The syndrome has generally been examined by using a medical or psychological approach, but during the last few years it has also been described and analysed from a nursing care perspective. From this nursing perspective the syndrome may be seen as an individual pattern developed by patients during their stay in an intensive care unit (ICU) and sometimes this pattern of clinical signs and symptoms lasts for a shorter or longer period even after discharge from the unit. From a wider viewpoint the development of the syndrome can be seen as an increase by degrees or as a vicious circle. finally, most authors agree that the ICU syndrome consists of, and is caused by, a complex interaction between many factors.

Pharmacokinetics and absolute bioavailability of epristeride in healthy male subjects

The objective of the current investigation was to describe the pharmacokinetics and absolute oral bioavailability of epristeride. Twelve healthy male subjects (mean (SD) age, 27 (6.2) years) received a single oral dose of 5 mg and an intravenous infusion of 4.5 mg over 30 min in a crossover fashion. Blood samples were obtained over 72h for the determination of epristeride plasma concentrations using a sensitive high-performance liquid chromatography assay. The lower limit of quantification was 5 ng mL-1. Pharmacokinetic analysis of the plasma concentration-time data was performed by both non-compartmental and compartmental methods. Absolute bioavailability was determined using dose-normalized AUC values following oral and intravenous administration. Epristeride plasma concentrations declined in a biexponential fashion with secondary peaks evident around 24 h in a majority of subjects following both routes of administration. Maximal plasma concentrations were typically achieved approximately 4 h after oral dosing. The mean apparent terminal elimination half-life estimates were similar following intravenous and oral administration and were 27.3 and 26.2 h, respectively. The mean plasma clearance and steady-state volume of distribution were 0.33 (0.09) mL min-1 kg-1 and 0.54 (0.17) L kg-1, respectively. The mean absolute bioavailability was 93% (95% CI: 84%, 104%). Following compartmental analysis of the intravenous data, the mean (SD) lambda 1 and lambda 2 half-life estimates were 2.74 (0.48) and 31.8 (19.5) h, respectively. The % AUC associated with the lambda 2 exponential phase was approximately 68%. This long half-life allows for once-daily dosing of epristeride.

A prospective survey of postoperative nausea and vomiting with special regard to incidence and relations to patient characteristics, anesthetic routines and surgical procedures

We performed a prospective study on 421 patients subjected to routine general-, orthopaedic-, urologic-, gynecological and paediatric surgery to estimate the current incidences of nausea and vomiting during the first 24 hours after surgery. The overall incidences of postoperative nausea or vomiting were 17% and 28%, respectively. Postoperative emetic symptoms were not related to age in adults. Women had more often emetic symptoms than men (P < 0.01). In general, opiate premedication was more frequently associated with postoperative nausea and vomiting than benzodiazepines (P < 0.01), but in otherwise comparable subgroups of patients undergoing major surgery, this difference was not confirmed. Balanced general anaesthesia caused more nausea (23%) and vomiting (53%) than face-mask anaesthesia (13% and 15%, respectively) or regional blocks (12% and 7%, respectively) (P < 0.001). There was a positive correlation between the duration of anaesthesia and the incidence of postoperative emetic symptoms (P < 0.001). The incidences of postoperative nausea and vomiting after abdominal surgery were 23% and 58% respectively. Corresponding figures for orthopaedic surgery were 25% and 34%, other kinds of extra-abdominal surgery 18% and 32% and for laparoscopy 21% and 25%. After minor gynecological-, urological- and paediatric surgery the incidences were less than 20%. In conclusion female gender, balanced anaesthesia, lengthy duration of anaesthesia, and abdominal and orthopaedic operations appeared to be most frequently associated with postoperative emetic symptoms.

Intestinal hemodynamics during laparotomy: effects of thoracic epidural anesthesia and dopamine in humans

The effects of thoracic epidural anesthesia (TEA) and dopamine infusion (4 micrograms.kg-1.min-1) on superior mesenteric artery blood flow (SMABF), the mesenteric arteriovenous oxygen difference (AVDO2), and the mesenteric venous lactate concentration were studied in nine patients before abdominal aortic reconstruction. Thoracic epidural anesthesia reduced SMABF, as measured by electromagnetic flowmetry, to 77% +/- 8% (mean +/- SEM) of control (P less than 0.05), and mean arterial pressure to 46% +/- 4% of control (P less than 0.01). The mesenteric AVDO2 increased from 27 +/- 3 to 39 +/- 6 mL/L (P less than 0.05) and superior mesenteric venous lactate from 1.03 +/- 0.11 to 1.60 +/- 0.38 mmol/kg (P less than 0.05); systemic AVDO2 and lactate did not change. Dopamine had no significant effect on SMABF and mean arterial pressure before TEA. However, dopamine increased SMABF during TEA (from 77% +/- 8% to 137% +/- 21% of control; P less than 0.01), returned mesenteric AVDO2 to 27 +/- 3 mL/L (P less than 0.05), and elevated mean arterial pressure to 62% +/- 4% of control (P less than 0.05). It is concluded that the decrease in perfusion pressure during TEA reduces SMABF with resultant evidence of intestinal reductive metabolism. The intestinal blood flow during TEA was improved by dopamine.

Dopamine counteracts hypertension during general anesthesia and hypotension during combined thoracic epidural anesthesia for abdominal aortic surgery

The influence of the degree of sympathetic nervous system activation on the cardiovascular effects of dopamine was studied during abdominal aortic surgery in 13 patients. The arterial plasma norepinephrine concentration (NE) was used as an index of sympathetic nervous system activity. During anesthesia with nitrous oxide and fentanyl, 7 patients (group 1) had a NE above 700 pg/mL and an increased mean arterial pressure (MAP) compared with the preanesthetic level (150 +/- 6 v 117 +/- 10 mm Hg; p less than 0.01, mean +/- SEM). The other 6 patients (group 2) had no significant change in MAP compared with the preanesthetic MAP (119 +/- 7 v 105 +/- 4 mm Hg). Dopamine, 4 micrograms/kg/min, decreased MAP in group 1 by 19% (150 +/- 6 to 121 +/- 8 mm Hg; P less than 0.05) because of a 32% +/- 9% decrease (P less than 0.05) in systemic vascular resistance. MAP was not altered by dopamine in group 2 (119 +/- 7 v 123 +/- 6 mm Hg; not significant). Following termination of dopamine, the anesthetic was supplemented with thoracic epidural anesthesia (TEA). This reduced MAP to 65 +/- 7 mm Hg (P less than 0.01) and 56 +/- 3 mm Hg (P less than 0.01), and NE to 441 +/- 76 (P less than 0.05) and 235 +/- 45 pg/mL (P less than 0.05) in groups 1 and 2, respectively. During TEA, dopamine increased MAP similarly in both groups, to 85 +/- 7 mm Hg (P less than 0.01) and 82 +/- 9 mm Hg (P less than 0.05), respectively. In conclusion, dopamine, at the same dosages, counteracted hypertension during general anesthesia and counteracted hypotension during general anesthesia combined with TEA.

Membrane expression of platelet calpain

Platelet calpain has many platelet substrates, including external membrane proteins. We thus investigated whether platelet calpain II was associated with platelet membranes in unstimulated and thrombin-activated platelets. A monospecific, goat polyclonal antibody was reared to purified platelet calpain II. Sixteen whole platelet lysates were found to contain 4.5 +/- 0.7 micrograms calpain antigen II per 10(8) platelets (mean +/- SEM) as determined by a competitive enzyme-linked immunosorbent assay. Using the dipeptide fluorogenic substrate, Suc-Leu-Tyr-MCA, 17 human platelet lysates contained 3.6 +/- 0.4 micrograms calpain activity per 10(8) platelets. Platelet calpain II was associated with the Triton X-100 insoluble platelet cytoskeletons from both unstimulated and thrombin-activated platelets. When compared with the total cell content of platelet calpain II, calpain antigen (10% to 13%) and calpain activity (24% to 28%) was associated with platelet cytoskeletons in unstimulated and thrombin-activated platelets, respectively. On immunoblot, the heavy chain (80 Kd) of calpain II was detected in platelet cytoskeletons. Subcellular fractionation studies on both unstimulated and thrombin-activated platelets, revealed that half of the total platelet calpain II antigen was associated with cytosol, and the other half was associated with the membrane fraction. Platelet calpain II was not seen on the surface of unstimulated, paraformaldehyde fixed platelets by immunofluorescence. However, on thrombin-activated platelets, rim immunofluorescence was seen, indicating that activated platelets externalize their calpain. This observation was confirmed by the finding that about 2,000 molecules per platelet of an 125I-anti-calpain II Fab' specifically bound to thrombin-activated but not unstimulated platelets. Both dibucaine (1 mmol/L) and platelet activating factor (1.86 mumol/L) in the absence of external Ca++, but not collagen (5 micrograms/mL) or ionophore A23187 (2.5 mumol/L) in the absence of external Ca++, were also able to externalize platelet calpain II antigen, as indicated by a similar level of specific 125I-anti-calpain II Fab'-platelet binding. These combined studies indicate that platelet calpain II is a major protein, comprising 2% of total platelet protein, a substantial portion of which is membrane-associated. When platelets are activated by thrombin and platelet activating factor, calpain II antigen also becomes present on the external platelet surface.

The expression of high molecular weight kininogen on human umbilical vein endothelial cells

High molecular weight kininogen (HMWK) functions as a cofactor for activation of plasma serine zymogens and as an inhibitor of tissue cysteine proteases. Cell surfaces to which HMWK binds may provide sites for regulation of these systems. Localization of these HMWK-dependent processes at sites of vascular injury may depend on its binding to specific receptors on endothelial cells. In culture, passaged human umbilical vein endothelial cells (HUVEC) bind anti-HMWK antibody to the cell surface and contain 171 +/- 75 ng of HMWK/10(8) cells. [35S]Methionine-labeled HUVEC in culture synthesize a 120-kDa protein immunoisolated using an anti-kininogen antibody, and a 3500-nucleotide message for human HMWK was detected by Northern blot in RNA extracted from HUVEC. HUVEC also express unoccupied binding sites for HMWK on their surface. 125I-HMWK specifically binds to HUVEC in a reaction requiring Zn2+. 125I-HMWK binding to HUVEC is saturable at 4 degrees C but not at 23 degrees C. 125I-HMWK binds to HUVEC with equal affinity as unlabeled HMWK. Kallikrein, factor XII, fibrinogen, fibronectin, and thrombin do not inhibit 125I-HMWK binding to HUVEC. 125I-HMWK-HUVEC binding remains fully reversible at 60 min following the addition of a 50-fold molar excess HMWK. HUVEC express 9.3 +/- 2.0 X 10(5) (mean +/- S.E.) HMWK binding sites/cell (Kd = 52 +/- 13 nM). Both added and cell-bound 125I-HMWK migrate at 120 kDa on sodium dodecyl sulfate gel electrophoresis, suggesting that the protein remains uncleaved upon binding to the HUVEC surface. These studies indicate that HUVEC synthesize HMWK and the HUVEC surface has a site for its expression. By synthesizing and localizing HMWK to the cell surface, endothelial cells may contribute to the activation of plasma's contact serine zymogens and regulation of tissue cysteine proteases.

Premedication with intramuscular dixyrazine: (Esucos). A controlled double-blind comparison with morphine-scopolamine and placebo

Ninety patients scheduled for general or orthopaedic surgical procedures were randomly assigned to receive one of three i.m. premedications: dixyrazine 0.5 mg kg-1; morphine 0.15 mg kg-1 and scopolamine 0.0065 mg kg-1; or placebo. The premedication was administered and evaluated in a double-blind fashion. The patients were anaesthetized with thiopentone, fentanyl, pancuronium, and ventilated with nitrous oxide in oxygen. The three premedications had no noticeable anxiolytic effect. Although there was no difference in the frequency of observed postoperative nausea and vomiting between the three groups, premedication with dixyrazine nonetheless reduced the patients' experience of postoperative nausea as well as their need for postoperative antiemetics. Although patients in the two treatment groups were significantly more sedated immediately before induction of anaesthesia than patients receiving placebo, the degree of postoperative sedation was similar in all three groups. Morphine-scopolamine caused more postoperative dizziness than dixyrazine and placebo. Lack of recall was produced by both morphine-scopolamine and dixyrazine. It is concluded that premedication with dixyrazine is a useful alternative, especially in patients who have previously experienced postoperative nausea and vomiting.

Septic shock in the rat: activation of plasma proteolytic systems and effects of a kallikrein inhibitor/bradykinin antagonist (S-2441)

Septic shock was induced in rats by intraperitoneal injection of live Escherichia coli. Plasma prekallikrein, antithrombin III and plasminogen levels were studied with chromogenic peptide substrate assays. Decrease of all the studied plasma components occurred in all rats, but not until late in shock. S-2441, a kallikrein inhibitor/kinin antagonist, slightly delayed the fall in plasma prekallikrein, but no other effects were found. Rat survival was neither enhanced nor prolonged.

Changes in cerebrospinal fluid homovanillic acid in children with Ondine's curse

The cerebrospinal fluid (CSF) concentrations of three acid monoamine metabolites, two purines, and a group of amino acids were determined in two children with chronic central alveolar hypoventilation (Ondine's curse). The levels of all assayed neuroactive substances, metabolites, and amino acids, with one exception, were normal compared to an age-matched group of neurologically healthy children. The levels of the dopamine metabolite homovanillic acid in the children with Ondine's curse were approximately 2.4 times higher than expected for age range. The present findings may indicate a link between central nervous system dopamine activity and chronic central alveolar hypoventilation. Among other possible explanations, the changes seen might represent a primary alteration in dopamine activity or may reflect a change in dopamine turnover resulting from the chronic hypoventilation.

Propofol vs thiopentone as anaesthetic agents for short operative procedures

In a randomized open study, 120 healthy female patients were included. For short gynaecological procedures they were anaesthetized with either propofol 2.5 mg X kg-1 (n = 60) or thiopentone 5 mg X kg-1 (n = 60) in combination with nitrous oxide/oxygen (67%/33%). Supplementary doses of propofol (10-20 mg) or thiopentone (25-50 mg) were given when necessary during the procedure. Induction characteristics for propofol and thiopentone 1 min after start of induction were similar. Propofol seemed to have a more depressant effect than thiopentone on the circulatory response to anaesthesia. Recovery times from the end of the operative procedure until the patients opened their eyes on command and were orientated were shorter in the propofol patients compared to the thiopentone patients. In the propofol group, patients recalled discomfort on injection more often than patients anaesthetized with thiopentone. Otherwise, the side-effects were similar in both groups. We conclude that propofol is similar to thiopentone in its anaesthetic qualities during induction and maintenance of short anaesthetic procedures. Propofol was associated with a more rapid emergence from anaesthesia than thiopentone.

Clonidine and the sympatico-adrenal response to coronary artery by-pass surgery

Clonidine was administered intravenously in an attempt to limit sympatico-adrenal activity and thereby reduce the incidence of arterial hypertension associated with coronary artery by-pass graft surgery (CABG). Forty patients scheduled for CABG were assigned to two groups. Twenty patients received clonidine 4 micrograms kg-1 before surgery, 2 micrograms kg-1 after cardiopulmonary by-pass and 1 microgram kg-1 when the skin was sutured. The other 20 patients served as controls. All patients were anesthetized with fentanyl, droperidol, nitrous oxide and alcuronium. During surgery 5 min after sternotomy, mean arterial pressure was 13 mmHg lower (P less than 0.01) in the clonidine group, while after operation the difference between the groups was negligible. Both during and after surgery the plasma catecholamine concentrations were significantly lower in the clonidine group (P less than 0.01). The greatest difference between the groups was seen 90 min after operation, when plasma noradrenaline and plasma adrenaline concentrations in the clonidine group were less than 1/3 of those in the control group (P less than 0.01). As judged by catecholamine concentrations clonidine was effective in attenuating sympatico-adrenal hyperactivity during and after surgery. Postoperative arterial hypertension was not reduced, however, and it is concluded that other factors besides sympatico-adrenal hyperactivity must be important.

Cardiovascular effects of enflurane and asphyxia during long-term beta 1-adrenoceptor blockade

The haemodynamic effects of enflurane (1.7% and 3.4% expiratory concentrations) were investigated in sheep (n = 6) pretreated with an infusion of metoprolol (0.2 mg X kg-1 X h-1 for 5 days) and in control animals (n = 6). Chloralose was used as basal anaesthetic. A 90 s apnoea period was included in the experiment to evaluate further the possible side-effects of long-term metoprolol treatment in combination with enflurane anaesthesia. MAC 1.0 for enflurane in the sheep was found at 1.45% end-tidal concentration by separate measurements. Before enflurane administration, the only significant differences between the two groups of animals were a lower systemic vascular resistance and a higher stroke volume during metoprolol treatment. Enflurane abolished these discrepancies in a dose-dependent fashion and similar cardiovascular depression was observed in both groups of animals at 3.4% expiratory concentration of enflurane. Metoprolol did not significantly affect the hypertensive response to apnoea during chloralose anaesthesia alone. At enflurane 1.7% expiratory concentration the apnoea response was small and only the metoprolol-treated animals showed a significant increase in left ventricular end-diastolic pressure. We conclude that 5 days of pretreatment with metoprolol in the sheep model does not significantly impair cardiovascular performance during enflurane anaesthesia.