bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermodilution cardiac output
Authors: Berthelsen P. G. , Eldrup N. , Nilsson L. B. , Rasmussen J. P.
Published: March 2003

Background: The feasibility of thermodilution cardiac output measurements with the more convenient room temperature thermal indicator instead of cold injectates has been repeatedly investigated. However, the issue has not been addressed with the appropriate statistical approach advocated by Altman and Bland. Furthermore, we wished to determine if the incorporation of a second thermistor in the thermodilution catheter, to measure the temperature of the thermal indicator where it is delivered into the right atrium/superior caval vein, would result in more precise cardiac output measurements.

Methods: Fifty patients were randomized to receive a single or dual thermistor pulmonary artery thermodilution catheter. Cardiac output was calculated as the average of four injections of 10 ml of isotonic saline. Precision (2 × SD of differences in replicate measurements) for the two catheters and injectate temperatures, and bias and limits of agreement between measurements, with cold and room temperature injectates, were determined.

Results: Precision was (0°C) 0.42 l/min and (20°C) 0.90 l/min, and bias and limits of agreement −0.83 l/min and −1.93–0.27 l/min for the single thermistor catheter. For the dual thermistor system precision was (0°C) 0.34 l/min and (20°C) 0.58 l/min. Bias and limits of agreement were −0.03 l/min and −0.61–0.55 l/min.

Conclusion: The second thermistor is redundant if cold injectates are used. If one wishes to use room temperature injectates the single thermistor system is inadequate. A dual thermistor catheter is, on the other hand, acceptable.
Bactericidal/permeability‐increasing protein inhibits endotoxin‐induced vascular nitric oxide synthesis
Authors: Ciornei C. D. , Egesten A. , Engström M. , Törnebrandt K. , Bodelsson M.
Published: March 2003

Background: Endotoxin (lipopolysaccharide, LPS) up‐regulates inducible nitric oxide synthase (iNOS) in blood vessels during septic shock. This promotes the production of nitric oxide (NO), leading to dilation of the vessels. The aim of the study was to investigate the effects of the LPS‐binding endogenous antibiotic bactericidal/permeability‐increasing protein (BPI) on the action of LPS on the blood vessels wall and to identify possible influence on underlying NO‐related mechanisms.

Methods: Isolated segments of rat thoracic aorta and cultured primary smooth muscle cells were incubated for 5–48 h in the presence of the following combinations of compounds: (a) LPS; (b) interleukin‐1β (IL‐1β); (c) BPI; (d) BPI + LPS; (e) BPI + IL‐1β or (f) neither BPI, LPS nor IL‐1β (control). After incubation of intact segments, we measured smooth muscle contraction in response to phenylephrine and accumulation of the NO end products nitrate and nitrite in surrounding medium. Western blot was used to assess the levels of inducible nitric oxide synthase (iNOS) in cultured cells.

Results: Both LPS and IL‐1β decreased contractility and increased NO production, as well as iNOS. Co‐incubation with BPI attenuated all the effects of LPS but only the effects of prolonged exposure to IL‐1β in cultured cells.

Conclusion: We conclude that BPI attenuates the LPS‐induced changes in vascular reactivity by inhibiting the expression of iNOS resulting in decreased NO formation and restored responsiveness to vasoconstrictors. The data suggest that BPI can prevent circulatory disturbances during Gram‐negative sepsis.
Consultants' opinion on a new practice‐based assessment programme for first‐year residents in anaesthesiology
Authors: Ringsted C. , Østergaard D. , Scherpbier A.
Published: March 2003

Background: Assessment in postgraduate education is moving towards using a broad spectrum of practice‐based assessment methods. This approach was recently introduced in first‐year residency in anaesthesiology in Denmark. The new assessment programme covers: clinical skills, communication skills, organizational skills and collaborative skills, scholarly proficiencies and professionalism. Eighteen out of a total of 21 assessment instruments were used for pass/fail decisions. The aim of this study was to survey consultants' opinions of the programme in terms of the representativeness of competencies tested, the suitability of the programme as a basis for pass/fail decisions and the relevance and sufficiency of the content of the different assessment instruments.

Methods: A description of the assessment programme and a questionnaire were sent to all consultants of anaesthesiology in Denmark. The questionnaire consisted of items, to be answered on a five‐point scale, asking the consultants' opinions about representativeness, suitability and content of the programme.

Results: The response rate was 251/382 (66%). More than 75% of the respondents agreed that the assessment programme offered adequate coverage of the competencies of a first‐year resident and was appropriate for making pass/fail decisions. There was strong agreement that the content of the 18 tests used for pass/fail decisions was relevant and sufficient for pass/fail decisions.

Conclusion: Judging from the consultants' opinions, the assessment programme for first‐year residency in anaesthesiology appears to be appropriate regarding the range of competencies assessed, the appropriateness as a basis for pass/fail decisions, and regarding the content of the tests used for pass/fail decisions. Further studies are needed to assess the feasibility and acceptability of the programme in practice.
Permanent sensorineural hearing loss following spinal anesthesia
Authors: Kiliçkan L. , Gürkan Y. , Ozkarakas H.
Published: March 2003

A 25‐year‐old female developed permanent, fluctuating sensorineural hearing loss (SNHL), disabling vertigo, and tinnitus following an uneventful spinal anesthesia for cesarean section. At her first visit to the ear‐nose‐throat (ENT) department approximately 2 months postoperatively, pure‐tone thresholds revealed profound SNHL on the right side whereas thresholds were within normal limits on the left side. The recruitment score (SISI) was 95% at 2000 Hz on the right side. Directional preponderance towards the right and the right canal paresis were evidenced by bithermal caloric testing. At follow ups the pure tone thresholds have shown some improvement, but fluctuating SNHL, disabling vertigo attacks, and tinnitus have remained. These findings imply a cochlear pathology causing endolymphatic hydrops possibly induced by lumbar puncture for spinal anesthesia.
Sudden cardiac arrest immediately after aortic cross clamping during abdominal aortic aneurysm repair
Authors: Aono J. , Ueda K. , Hendry J. , Kitamura F.
Published: March 2003

We report a case of sudden cardiac arrest immediately after aortic cross clamping during surgery for infrarenal abdominal aortic aneurysm in a patient with coronary artery disease. The cause, treatment, and necessary monitoring for the case are discussed.
Paraplegia associated with combined spinal‐epidural anaesthesia caused by preoperatively unrecognized spinal vertebral metastasis
Authors: Kararmaz A. , Turhanoglu A. , Arslan H. , Kaya S. , Turhanoglu S.
Published: March 2003

We describe a case of paraplegia following combined spinal‐epidural anaesthesia. It was postoperatively determined that a tumour of the vertebrae which was compressing the spinal cord was responsible for this complication. We suggest that the pre‐existing pathology of the spine must be borne in mind as a differential diagnosis of acute postoperative paraplegia.
Does dopexamine influence regional vascular tone and oxygenation during intestinal hypotension?
Authors: Lehtipalo S. , Biber B. , Fröjse R. , Arnerlöv C. , Johansson G. , Winsö O.
Published: March 2003

Background: Local effects of dopexamine on intestinal vascular tone and oxygenation were investigated during intestinal hypotension. To this end, we employed an experimental model, in which the superior mesenteric arterial pressure (PSMA) was controlled by an adjustable perivascular clamp. This approach enabled us to keep the intestinal perfusion pressure (IPP) constant in the face of any systemic circulatory alterations.

Methods: In 11 barbiturate‐anesthetized pigs, we instrumented the superior mesenteric circulation for assessments of vascular resistance (RMES), IPP, jejunal mucosal perfusion (Laser Doppler) and intestinal tissue oxygenation (microoximetry). Measurements were carried out before and during dopexamine infusions (0.5 and 1.0 µg·kg−1·min−1) at a freely variable PSMA (i.e. the perivascular clamp fully open) and at a PSMA of 50 mmHg and 30 mmHg.

Results:  At a constant PSMA of 50 mmHg, dopexamine had no significant intestinal vascular effects. However, at a constant PSMA of 30 mmHg, both doses of dopexamine were associated with decreases in RMES. Effects of dopexamine on intestinal oxygen delivery and extraction were minimal during these procedures, while a minor decrease in intestinal tissue oxygen tension was observed during dopexamine administration at the lowest IPP level.

Conclusion: At very low intestinal perfusion pressures (approximately 30 mmHg) dopexamine produces intestinal vasodilation in excess of what is produced by intrinsic autoregulation. This suggests that there is a vasodilatory reserve in the intestine under such conditions and that a pharmacological vasodilator like dopexamine may improve intestinal circulation during regional severe hypotension.
Preoperative predictors of moderate to intense acute postoperative pain in patients undergoing abdominal surgery
Authors: Caumo W. , Schmidt A. P. , Schneider C. N. , Bergmann J. , Iwamoto C. W. , Adamatti L. C. , Bandeira D. , Ferreira M. B. C.
Published: March 2003

Background:  Pain is a sensory and emotional experience that is influenced by physiologic, sensory, affective, cognitive, socio‐cultural, and behavioral factors. Consistent with the perspective to improve the postoperative pain control, the present study has the purpose of assessing the effect of presurgical clinical factors, psychological and demographic characteristics as predictors for reporting moderate to intense acute postoperative pain.

Methods:A prospective cohort study was performed with 346 inpatients undergoing abdominal elective surgery (ASA physical status I‐III, age range 18–60 years). The measuring instruments were Pain Visual Analog Scale, the State‐Trait Anxiety Inventory, and the Montgomery‐Åsberg Depression Rating Scale. Multivariate conditional regression modeling was used to determine independent predictors for moderate to intense acute postoperative pain.

Results:  Moderate to intense acute postoperative pain was associated with status ASA III (odds ratio (OR) = 1.99), age (OR = 4.72), preoperative moderate to intense pain (OR = 2.96), chronic pain (OR = 1.75), high trait‐anxiety and depressive mood moderate to intense (OR = 1.74 and OR = 2.00, respectively). Patients undergoing surgery to treat cancer presented lower risk for reporting moderate to intense pain OR = 0.39, as well as those that received the epidural analgesia and multimodal analgesia with systemic opioid (OR = 0.09 and OR = 0.16, respectively).

Conclusions:The identification of predictive factors for intense acute postoperative pain may be useful for designing specific preventive interventions to relieve patient suffering. Especially because few of these variables are accessible for medical intervention, which would improve the clinical outcomes and quality of life of patients at risk of moderate to intense acute postoperative pain.
Victims of awareness
Authors: Lennmarken C. , Bildfors K. , Enlund G. , Samuelsson P. , Sandin R.
Published: March 2003

Background: Intraoperative awareness with explicit recall may be followed by long‐lasting mental symptoms. However, the average risk for developing mental sequelae after awareness, and the average severity and the duration of symptoms has not previously been illustrated in a consecutive series of awareness cases.

Methods: Nine patients among 18 consecutive, prospectively identified cases of intraoperative awareness with recall could be located after approximately 2 years and agreed to an interview about possible persisting problems.

Results: Four of the nine interviewed patients were still severely disabled due to psychiatric/psychological sequelae. All of these patients had experienced anxiety during the period of awareness, but only one had complained about pain. Another three patients had less severe, transient mental symptoms, although they could cope with these in daily life. Two patients denied any sequelae from their awareness episode.

Conclusions: Up to 3 weeks after their unsuccessful anesthetic, repeated information and discussions had been offered. Despite the fact that all patients at that time claimed to be satisfied with this management, and eventually considered no further contacts necessary, this was obviously inaccurate. Therefore, professional psychiatric assessment, treatment and long‐term follow‐up should constitute standard practice for all patients who have experienced intraoperative awareness.
Comparison of auditory evoked potentials and the A‐line ARX Index for monitoring the hypnotic level during sevoflurane and propofol induction
Authors: Litvan H. , Jensen E. W. , Revuelta M. , Henneberg S. W. , Paniagua P. , Campos J. M. , Martínez P. , Caminal P. , Villar Landeira J. M.
Published: March 2003

Background: Extraction of the middle latency auditory evoked potentials (AEP) by an auto regressive model with exogenous input (ARX) enables extraction of the AEP within 1.7 s. In this way, the depth of hypnosis can be monitored at almost real‐time. However, the identification and the interpretation of the appropriate signals of the AEP could be difficult to perform during the anesthesia procedure. This problem was addressed by defining an index which reflected the peak amplitudes and latencies of the AEP, developed to improve the clinical interpretation of the AEP. This index was defined as the A‐line Arx Index (AAI).

Methods: The AEP and AAI were compared with the Modified Observers Assessment of Alertness and Sedation Scale (MOAAS) in 24 patients scheduled for cardiac surgery, anesthetized with propofol or sevoflurane.

Results: When comparing the AEP peak latencies and amplitudes and the AAI, measured at MOAAS level 5 and level 1, significant differences were achieved. (mean(SD) Nb latency: MOAAS 5 51.1 (7.3) ms vs. MOAAS 1: 68.6 (8.1) ms; AAI: MOAAS 5 74.9 (13.3) vs. MOAAS 1 20.7 (4.7)). Among the recorded parameters, the AAI was the best predictor of the awake/anesthetized states.

Conclusion: We conclude that both the AAI values and the AEP peak latencies and amplitudes correlated well with the MOAAS levels 5 (awake) and 1 (anesthetized).
Ropivacaine 2 mg/mL vs. bupivacaine 1.25 mg/mL with sufentanil using patient‐controlled epidural analgesia in labour
Authors: Hofmann‐Kiefer K. , Saran K. , Brederode A. , Bernasconi H. , Zwissler B. , Schwender D.
Published: March 2003

Background: In recent studies, minimum local analgesic concentrations have been defined as 0.93 mg/mL for bupivacaine and 1.56 mg/mL for ropivacaine for epidural analgesia for the first stage of labour, resulting in an analgesic potency ratio of 1 : 0.6. In the current study we compared ropivacaine and bupivacaine in a PCEA system (combined with sufentanil) taking this potency ratio into account but administering drug doses providing sufficient analgesia for all stages of labour.

Methods: In a prospective, double‐blinded study 114 parturients were randomised to receive either ropivacaine 2 mg/mL with sufentanil 0.75 µg/mL or bupivacaine 1.25 mg/with sufentanil 0.75 µg/mL. After epidural catheter placement, PCEA was available with boluses of 4 mL, a lock‐out time of 20 min and no basal infusion rate. We evaluated pain intensity during contractions, sensory and motor function, duration of labour, mode of delivery and neonatal outcome. Consumption of local anaesthetic and opioid drugs and PCEA system variables were recorded.

Results: Mean total consumption as well as mean hourly drug consumption was significantly increased in the ropivacaine–sufentanil group. No differences in analgesic quality, sensory or motor blocking potencies or neonatal outcome variables between groups were detected. Frequency of instrumental deliveries was significantly increased in the ropivacaine–sufentanil group.

Conclusions: The results support the findings of previously published studies postulating ropivacaine to be 40–50% less potent for labour epidural analgesia compared to bupivacaine. However, we observed an increased frequency of instrumental deliveries with ropivacaine. To evaluate the clinical relevance of these findings, further investigations are warranted.
The difference between sleep and anaesthesia is in the intracellular signal: propofol and GABA use different subtypes of the GABAA receptor β subunit and vary in their interaction with actin
Authors: Björnström K. , Eintrei C.
Published: March 2003

Background: Propofol is known to interact with the γ‐aminobutyric acidA (GABAA) receptor, however, activating the receptor alone is not sufficient for producing anaesthesia.

Methods: To compare propofol and GABA, their interaction with the GABAA receptor β subunit and actin were studied in three cellular fractions of cultured rat neurons using Western blot technique.

Results: Propofol tyrosine phosphorylated the GABAA receptor β2 (MW 54 and 56 kDa) and β3 (MW 57 kDa) subtypes. The increase was shown in both the cytoskeleton (β2(54) and β2(56) subtypes) and the cell membrane (β2(54) and β3 subtypes). Concurrently the 56 kDa β2 subtype was reduced in the cytosol. Propofol, but not GABA, also tyrosine phosphorylated actin in the cell membrane and cytoskeletal fraction. Without extracellular calcium available, the amount of actin decreased in the cytoskeleton, but tyrosine phosphorylation was unchanged. GABA caused increased tyrosine phosphorylation of β2(56) and β3 subtypes in the membrane and both β2 subtypes in the cytoskeleton but no cytosolic tyrosine phosphorylation.

Conclusion: The difference between propofol and GABA at the GABAA receptor was shown to take place in the membrane, where the β2(54) was increased by propofol and instead the β2(56) subtype was increased by GABA. Only propofol also tyrosine phosphorylated actin in the cell membrane and cytoskeletal fraction. This interaction between the GABAA receptor and actin might explain the difference between anaesthesia and physiological neuronal inhibition.
No influence of the endothelin receptor antagonist bosentan on basal and indomethacin‐induced reduction of cerebral blood flow in pigs
Authors: Rasmussen M. , Poulsen P. H. , Treiber A. , Delahaye S. , Tankisi A. , Cold G. E. , Therkelsen K. , Gjedde A. , Astrup J.
Published: March 2003

Background: The mechanism behind indomethacin‐induced cerebral vasoconstriction is incompletely understood. We tested the hypothesis that the mixed endothelin‐1 receptor antagonist bosentan would modify or prevent indomethacin‐induced reduction of CBF in the anaesthetized pig. Furthermore, we investigated the effect of bosentan on resting CBF and CMRO2.

Methods: Twelve pigs were randomized in two groups of six, and received either bosentan and indomethacin (group 1), or placebo and indomethacin (group 2). Anaesthesia was induced with ketamine and midazolam and maintained with fentanyl, nitrous oxide and pancuronium. Baseline measurements of CBF and CMRO2 were performed before intravenous bolus injection of bosentan (10 mg/kg) or placebo (0.9% NaCl). The second CBF and CMRO2 measurement was performed 30 min after administration of bosentan/placebo. A 40‐min infusion of indomethacin (0.05 mg/kg/min) was administered and the third CBF and CMRO2 measurement was performed 80 min after administration of bosentan/placebo. Independently, pharmacokinetic data of bosentan were generated in four pigs.

Results: In group 1, baseline CBF was 55 ± 7 ml/100 cm3/min. Administration of bosentan i.v. did not change CBF significantly. Indomethacin decreased CBF to 41 ± 5 ml/100 cm3/min (P < 0.002). In group 2, baseline CBF was 54 ± 10 ml/100 cm3/min. Placebo did not change CBF while indomethacin decreased CBF significantly to 41 ± 5 ml/100 cm3/min (P < 0.002). No significant changes in CMRO2 were observed. In group 2, a significant increase in MABP was observed after administration of indomethacin. No change in MABP was observed in the bosentan‐treated animals. Total plasma concentrations of bosentan at the time of the first and the second PET measurement were 3.9 and 1.4 µg/ml, respectively. The corresponding values for the pharmacologically active metabolite Ro 48–5033 were 1.2 and 0.4 µg/ml.

Conclusion: These findings indicate that endothelin receptor stimulation is not involved in indomethacin‐induced cerebral vasoconstriction or maintenance of cerebrovascular tone in the anaesthetized pig. However, our results suggest that the increase in MABP is mediated through endothelin receptors.
Death after injury in rural Norway: high rate of mortality and prehospital death
Authors: Wisborg T. , Høylo T. , Siem G.
Published: March 2003

Background: Finnmark is a rural and remote area in Norway with a sparse population and long distances. Trauma‐related mortality has been consistently above the Norwegian national average for the last 20 years. Although the causes of death are well established, very little is known about the time and place of death. This information has implications for the organization of emergency services in rural areas. We examined all trauma deaths over a five‐year period in order to inform the debate on how best to reduce our above‐average mortality rate.

Methods: A retrospective study of all deaths after trauma (ICD‐9 E800‐E999) during the years 1991–95 using data obtained from the National Registry of Death.

Results: Of the 183 cases found, 130 deaths were due to trauma using definitions comparable to similar studies. The mortality rate was 77 per 100 000 inhabitants per year. Death occurred in the prehospital phase in 85% of cases. Seventy‐two per cent of all deaths (regardless of location) occurred within the first h after injury, eight per cent from 1 to 4 h and the remaining 20% occurred after 4 h.

Conclusion: When planning interventions to reduce the mortality rate from trauma in rural areas, a high proportion of prehospital deaths should be expected. The high number of patients who are found dead (which can only be reduced by injury prevention) must be taken into account. Measures to reduce ‘preventable’ causes of death by bystanders should be evaluated. Further knowledge of exact mechanisms of death in the prehospital phase is required.
Complete recovery from prolonged cardio‐pulmonary resuscitation following anaphylactic reaction to readministered intravenous cefazolin
Authors: Gibbs M. W. , Kuczkowski K. M. , Benumof J. L.
Published: March 2003

We describe a patient who developed a type I anaphylactic reaction to intravenous cefazolin. The patient had no known drug allergies and had previously received intraoperative intravenous cefazolin 2 months prior without any problems. Forty‐fives after receiving cefazolin 1 g i.v. and while fully awake, the patient experienced shortness of breath, became unconscious, and then suffered a cardiac arrest. Resuscitation included endotracheal intubation, external cardiac compression, electrical defibrillation and multiple large doses of epinephrine, atropine, and sodium bicarbonate over the course of 2.5 h and three cardiac arrests. Nevertheless, the patient fully recovered. The intent of this case report is to address widely held concerns regarding cross‐reactivity of cephalosporin, particularly cefazolin, to penicillin, the legitimacy of test dosing as a means to safely identify patients who will have an allergic reaction to cephalosporins and comment on patient‐related predictors of survival following cardiopulmonary resuscitation and the good outcome in this case.
Effects of preoperative oral carbohydrates and peptides on postoperative endocrine response, mobilization, nutrition and muscle function in abdominal surgery
Authors: Henriksen M. G. , Hessov I. , Dela F. , Vind Hansen H. , Haraldsted V. , Rodt S. Å.
Published: March 2003

Background: Surgery is succeeded by long‐lasting state of relative peripheral insulin resistance, which is reduced by giving glucose infusion or oral carbohydrate‐rich drinks immediate before operating instead of fasting. The aim of the present study was to investigate whether oral carbohydrate or carbohydrate with peptide drinks preoperatively instead of fasting would improve postoperative voluntary muscle strength, nutritional intake and ambulation, decrease postoperative fatigue, anxiety and discomfort, and reduce the endocrine response to surgery.

Methods: Forty‐eight patients were included and randomized into three groups to receive 2 × 400 ml of carbohydrate‐rich drinks or to fast overnight and allowed only water. Voluntary grip and quadriceps strength, body composition, pulmonary function, VAS‐score of eight parameters of wellbeing, muscle biopsies and insulin, glucagon, IGF‐1 and free fatty acids were measured before and after the operation. The basic postoperative regimen for all groups were immediate oral nutrition and early enforced mobilization.

Results: Significant postoperative decrease in glycogen synthase activity in the muscle biopsies was reduced in the intervention groups, and in combination, the intervention groups had a less reduced quadriceps strength after one week (−10% vs. −16%, NS) and one month (−5% vs. −13%, P < 0.05). Minor changes in the endocrine response to surgery were found without differences between the groups, and there were no differences between the groups in ambulation time, nutritional intake or subjective measures of wellbeing.
Preoperative blood pressure and catecholamines related to hypothermia during general anesthesia
Authors: Kasai T. , Hirose M. , Matsukawa T. , Takamata A. , Yaegashi K. , Tanaka Y.
Published: March 2003

Background: We previously demonstrated that preoperative blood pressure values affect intraoperative hypothermia during general anesthesia. We hypothesized that increased catecholamine secretion could be responsible for the relationship between preoperative blood pressure and hypothermia.

Methods: To evaluate the effect of preoperative systolic blood pressure (SBP) and plasma catecholamine levels on core temperature during general anesthesia, 40 male patients who were scheduled for open abdominal surgery were allocated to two groups: those whose preoperative SBP was 140 mmHg or greater (high SBP group, n = 20), and those whose SBP was less than 140 mmHg (normal SBP group, n = 20). Anesthesia was maintained with 0.4% isoflurane and opioids.

Results: The average age, height, and weight of the patients in the two groups did not differ. Preoperative SBP, mean blood pressure, diastolic blood pressure and heart rate in the high SBP group were significantly higher than those in the normal SBP group. Plasma norepinephrine concentrations in the high SBP group were significantly greater than those in the normal SBP group before and 1 h after the induction of anesthesia. Tympanic membrane temperatures in the normal SBP group started to decline further just after the induction of anesthesia, more so than that in the high SBP group. The vasoconstriction threshold in the normal SBP group was significantly lower than that in the high SBP group.

Conclusion: These results suggest that the higher levels of preoperative catecholamine secretion contributed to the lesser degree of intraoperative hypothermia observed in the high SBP group.
New mathematical model for the correct prediction of the exchangeable blood volume during acute normovolemic hemodilution
Authors: Meier J. , Kleen M. , Habler O. , Kemming G. , Messmer K.
Published: March 2003

Background: The blood volume that has to be exchanged for crystalloids and/or colloids during acute normovolemic hemodilution (ANH) in order to reach a preset target hemoglobin concentration (hb) is usually predicted by the Bourke and Smith formula developed in 1974. This formula systematically overestimates the ‘true’ exchangeable blood volume (EBV), a fact that may potentially endanger patients because the target hb will be missed and the normovolemic anemia might turn out to be more severe than a priori intended. Our objective was to develop a more accurate mathematical model of hemodilution kinetics and to validate this new model in animals and in patients undergoing ANH.

Methods: Twenty‐two anesthetized beagle dogs and 18 patients under balanced anesthesia underwent isovolemic hemodilution with hydroxyethyl starch (HAES 6%, 200 000) to a target hb of 7 g dl−1 or 9 g dl−1, respectively. Exchangeable blood volume predicted by use of the different mathematical models was compared with the blood volume actually exchanged to meet the preset target hb.

Results: Calculation of EBV by the Bourke and Smith formula (EBVB + S) systematically overestimated the volume actually exchanged (overestimation: dogs 15%, patients 20%), whereas our new iterative model predicted EBV (EBViterative) more reliably (overestimation: dogs 1%, patients 8%). In both cases EBVB + S differed significantly from the EBViterative.

Conclusion: Exchangeable blood volume is predicted more accurately by the new iterative model than by the Bourke and Smith formula. The iterative model leads to an improvement in patient safety and provides a physiologically adequate basis for future studies investigating the efficacy of ANH in reducing allogenic blood transfusions.
Effects of acute normovolemic hemodilution on ventriculoarterial coupling in dogs
Authors: Nozaki J. , Kitahata H. , Tanaka K. , Kawahito S. , Oshita S.
Published: March 2003

Background: Acute normovolemic hemodilution (ANH) causes a decrease in systemic vascular resistance. Similar to vasodilating drugs, ANH might modify ventriculoarterial coupling. Left ventricular elastance (Ees), effective arterial elastance (Ea), stroke work (SW), and pressure volume area (PVA) were used as indicators to examine the effects of ANH on this coupling.

Methods: After institutional approval eight dogs were anesthetized with isoflurane and subjected to measurements including aortic pressure, left ventricular (LV) pressure, and LV volume. Left ventricular volume was measured with a conductance catheter. Ees was determined as the slope of the end‐systolic pressure‐volume relationship. Ea was determined as the ratio of LV end‐systolic pressure to stroke volume. Ventriculoarterial coupling was evaluated as the ratio of Ees to Ea. Mechanical efficiency, another criterion for ventriculoarterial coupling, was calculated as the ratio of SW to PVA. Data are expressed as mean±SD, and P<0.05 was considered significant.

Results: Normovolemic exchange of 50 ml kg−1 of blood for 6% hydroxyethyl starch (ANH50) reduced hemoglobin concentration from 12.8±3.0 g dl−1 to 6.4±1.3 g dl−1. Acute normovolemic hemodilution 50 did not change Ees significantly although it significantly decreased Ea. Left ventricular elastance/Ea did not change after ANH (1.0±0.4 at baseline and 1.2±0.5 at ANH50). Acute normovolemic hemodilution 50 significantly increased SW and PVA, preventing SW/PVA from changing significantly after ANH (0.57±0.10 at baseline and 0.62±0.14 at ANH50).

Conclusion: Before ANH, ventriculoarterial coupling was so matched as to maximize SW at the expense of the work efficiency. This relation was preserved at ANH50.
Remifentanil produces vasorelaxation in isolated rat thoracic aorta strips
Authors: ÜNlügenç H. , Itegin M. , ÖCal I. , ÖZalevli M. , Güler T. , Isik G.
Published: March 2003

Background: Remifentanil can cause transient instability in hemodynamic variables. However this change may not be solely the result of autonomic or central nervous system inhibition or of centrally mediated vagal stimulation. In this study, the aim was to examine the direct effects of remifentanil on isolated thoracic aorta strips in vitro.

Methods: Forty‐five Wistar rat thoracic aorta rings were isolated, and contraction–relaxation responses were recorded.

Results: In aortic rings precontracted with phenylephrine or potassium chloride, remifentanil produced concentration‐dependent relaxation in both endothelium‐intact and denuded rings (P<0.001). Remifentanil induced significantly greater relaxation in intact rings than in those denuded of endothelium, regardless of whether they were precontracted with phenylephrine hydrochloride or KCl (P<0.001). When the endothelium was present, remifentanil produced greater relaxation in KCl‐contracted rings than in PE‐contracted rings at lower concentrations (10−9 and 10−8), and similar relaxation at higher concentrations (10−7 and 10−6). However, when the endothelium was removed, relaxation was similar in both solutions, at all concentrations (10−9 to 10−6). In intact rings, pretreatment with L‐NO‐ARG or indomethacin reduced the degree of remifentanil‐induced relaxation. In Ca+ ± free media, calcium‐dependent KCl contractions were inhibited in a dose‐dependent manner by remifentanil (P<0.001).

Conclusion: Remifentanil vasodilates by an endothelium‐dependent mechanism, involving prostacyclin and nitric oxide released from the endothelium. Its endothelium‐independent vasodilation probably occurs via the suppression of voltage‐sensitive Ca++ channels.
The effects of hydroxyethyl starch solutions on thromboelastography in preoperative male patients
Authors: Felfernig M. , Franz A. , Bräunlich P. , Fohringer C. , Kozek‐Langenecker S. A.
Published: March 2003

Background: Hydroxyethyl starches (HES) have been shown to decrease clot strength and to increase coagulation times assessed by thromboelastography (TEG). HES with minimal anticoagulant side‐effects is beneficial for plasma volume expansion in the perioperative setting. A comparison of the in vivo effects of high, middle and low molecular weight HES solutions on TEG variables has not been performed so far.

Methods: Blood was obtained before and after intravenous infusion (10 ml kg−1) of either saline, HES 70/0.5/4 (molecular weight in kDa/degree of substitution/C2:C6 ratio), HES 130/0.4/9, HES 200/0.6/9.4, or HES 450/0.7/4.6 in 50 otherwise healthy patients. Thromboelastography was performed in 360 µl of 1% celite activated citrated whole blood after recalcification.

Results: HES 450/0.7/4.6 prolonged reaction time indicating impairment of the plasmatic coagulation system. TEG parameters indicative for platelet function, including angle α, maximum amplitude and coagulation time, deteriorated after infusion of HES 450/0.7/4.6 and HES 70/0.5/4. HES 200/0.6/9.4 and HES 130/0.4/9 impaired platelet contribution to hemostasis only partially, decreasing two or one TEG platelet parameters, respectively.

Conclusion: Infusion of HES 450/0.7/4.6 compromises TEG parameters more than the other solutions tested, whereas HES 130/0.4/9 has the smallest effect. Further outcome‐related studies are needed in order to assess the clinical relevance of our findings.
Comparison of granisetron and granisetron plus dexamethasone for the prevention of postoperative nausea and vomiting after laparoscopic cholecystectomy
Authors: Biswas B. N. , Rudra A.
Published: March 2003

Background: Laparoscopic cholecystectomies are associated with an appreciably high rate of postoperative nausea and vomiting (PONV). This study was designed to compare the effectiveness of granisetron plus dexamethasone with granisetron alone for the prevention of postoperative nausea and vomiting in patients after laparoscopic cholecystectomy.

Methods: In a randomized, double‐blind study, 120 patients of both sexes received granisetron 40 µg kg−1 alone or granisetron 40 µg kg−1 plus dexamethasone 8 mg (n=60 of each) intravenously immediately before induction of anesthesia. Perioperative anesthetic care was standardized in all patients. Patients were then observed for 24 h after administration of the study drug.

Results: A complete response (defined as no PONV and no need for another rescue antiemetic) was achieved in 83% of the patients given granisetron and in 95% of the patients given granisetron plus dexamethasone (P<0.05). The overall cumulative incidences (0–24 h) of PONV were 11 (18.3%) in the granisetron and three (5%) in the combination group. No difference in adverse events were observed in any of the groups.

Conclusion: The combination (granisetron plus dexamethasone) further increases the chance of complete response than granisetron alone. Therefore, the combination might be considered clinically relevant in a high risk setting.
Functional improvement after physiotherapy with a continuous infusion of local anaesthetics in patients with complex regional pain syndrome
Authors: Mak P. H. K. , Irwin M. G. , Tsui S. L.
Published: March 2003

Three patients were referred to our pain clinic with evidence of complex regional pain syndrome in their extremities. Two presented at the atrophic stage with joint contractures. Multiple analgesics had been prescribed without long‐lasting relief. Physiotherapy was required to improve physical activity but was severely limited by pain. We instituted local anaesthetic infusion with the possibility of self‐supplementation to facilitate physiotherapy; two via brachial plexus catheters for hand pain and one via epidural catheter for knee pain. Although their resultant pain scores were variable after cessation of local anaesthetic infusion, all the affected joints exhibited marked improvement in range of movement. We propose that this technique is a useful option for patients in all stages of complex regional pain syndrome where the emphasis is now directed toward functional improvement.
Decrease in the incidence of post‐dural puncture headache: maintaining CSF volume
Authors: Kuczkowski K. M. , Benumof J. L.
Published: March 2003

The incidence of epidural needle‐induced post‐dural puncture headache (PDPH) in parturients following dural puncture with a large bore (18‐gauge) needle has been reported to range 76–85%. We describe seven cases in which the performance of epidural anesthesia in parturients was complicated by an unintentional dural puncture with an 18‐gauge epidural needle. In all seven cases, the unintentional dural puncture was followed by (i) injection of the CSF in the glass syringe back into the subarachnoid space through the epidural needle, (ii) insertion of a epidural catheter into the subarachnoid space (now referred to as an intrathecal catheter), (iii) injection of a small amount of preservative free saline (3–5 ml) into the subarachnoid space through the intrathecal catheter, (iv) administration of bolus and then continuous intrathecal labor analgesia through the intrathecal catheter and then (v) leaving the intrathecal catheter in‐situ for a total of 12–20 h. PDPH occurred in only one of these cases (14%).
Influence of maternal, obstetric and fetal risk factors on the prevalence of birth asphyxia at term in a Swedish urban population
Authors:   Ian Milsom, Ladfors Lars , Thiringer Klara , Niklasson Aimon , Odeback Anders , Thornberg Eva
Published: March 2003

Background.  The influence of maternal, obstetric and fetal risk factors on the prevalence of birth asphyxia at term in a Swedish urban population.

Objective.  To investigate risk factors for Apgar score‐defined birth asphyxia, birth asphyxia with hypoxic‐ischemic encephalopathy and birth asphyxia‐related death/disability.

Material and methods.  Retrospective case‐control study in term neonates with birth asphyxia defined as Apgar score < 7 at 5 min. Cases originating from nonasphyctic causes (e.g. infection, maternal sedation) were excluded. Hypoxic‐ischemic encephalopathy was diagnosed according to criteria by Sarnat. Maternal, obstetric and fetal risk factors were registered in 225 cases of birth asphyxia diagnosed in 42 203 live births occurring in the urban Swedish population studied. A matched control group was used for statistical evaluation.

Results.  Asphyxia was associated with single civil status, OR = 7.1 (95%CI 2.0, 27.6); intrauterine meconium release, OR = 4.1 (95%CI 1.8, 9.8); operative delivery, OR = 8.7 (95%CI 3.4, 24.6); breech delivery, OR = 20.3 (95%CI 3.0, 416.5); oxytocin augmentation, OR = 2.9 (95%CI 1.4, 6.3); cord complication, OR = 15.8 (95%CI 2.1, 341.5); external compression to assist delivery OR = 6.2 (95%CI 1.3, 45.7); and cardiotocography score, OR = 0.5 (95%CI 0.4, 0.6). Normal fetal heart rate variability, OR = 0.4 (95%CI 0.2, 0.6), repeated late decelerations irrespective of amplitude or repeated variable decelerations, OR = 29.4 (95%CI 5.7, 540.8) or occasional late or variable decelerations, OR = 2.2 (95%CI 1.3, 3.8), and no accelerations, OR = 5.2 (95%CI 2.0, 16.4), were associated with asphyxia. Operative or instrumental delivery was more common in all three asphyxia groups compared with controls. Leanness was a risk factor for asphyxia and for hypoxic‐ischemic encephalopathy. Maternal age, smoking and illnesses, time of delivery (day/night, seasonal) and previous caesarean section were not associated with birth asphyxia.

Conclusions.  An association between neonatal asphyxia and cardiotocography parameters, intrauterine meconium release, operative delivery, breech delivery, single civil status, oxytocin augmentation, cord complication, external compression to assist delivery and neonatal leanness was found. Abnormal fetal heart rate variability, repeated late decelerations irrespective of amplitude or repeated variable decelerations, occasional late or variable decelerations and no accelerations were associated with asphyxia.
A Comparison of the Effects of Olopatadine and Ketotifen on Model Membranes
Authors: Brockman Howard , Graff Gustav , Spellman Joan , Yanni John
Published: March 2003

ABSTRACT. Olopatadine is a human conjunctival mast cell stabilizer with anti‐histaminic activity. Ketotifen is an older molecule that possesses antihistaminic activity and is reported to have additional pharmacological properties. The interactions of these two compounds with model membranes (i.e., monolayers of 1‐stearoyl‐2‐oleoyl‐sn‐glycerophosphocholine at the argon‐buffer interface), and natural (i.e., erythrocyte) membranes were compared in an effort to understand the differences in their biological activities. Drug‐lipid interaction with monolayers was determined by monitoring the surface pressure as a function of the drug concentration in the aqueous phase supporting the monolayer. Drug interaction with erythrocyte membranes was determined by monitoring changes in the permeability of the membranes to hemoglobin and 6‐carboxyfluorescein as a function of drug concentration in the medium. Olopatadine and ketotifen are both intrinsically surface active and both interact with phospholipid monolayers. However, in both the presence and absence of lipid monolayers, the changes in surface pressure induced by olopatadine are lower than those caused by ketotifen. The effects of these two drugs on cell membranes were dramatically different. Exposure of bovine erythrocytes to increasing concentrations of ketotifen (1–10 mM) resulted in complete hemolysis of the cells, whereas olopatadine (1–10 mM) caused only minimal hemolysis (<8%). Consistent results were obtained in experiments measuring the leakage of 6‐carboxyfluorescein from erythrocyte ghosts as a more sensitive marker of membrane perturbation. Olopatadine treatment (0.1–10 mM) minimally perturbed the cell membrane while ketotifen (1–10 mM) caused a concentration dependent release of the fluorescent marker. These data demonstrate fundamental differences between the two drugs in their effects on cell membranes. Moreover, the differences are consistent with the surface activities of the two compounds measured in monolayers and with reported differences in their pharmacological activities. These findings offer an explanation for the biphasic non‐specific cytotoxic effect of ketotifen on histamine release from mast cells and may account for the non‐lytic mast cell stabilizing activity of olopatadine.
Central corneal thickness, radius of the corneal curvature and intraocular pressure in normal subjects using non‐contact techniques: Reykjavik Eye Study
Authors: Eysteinsson Thor , Jonasson Fridbert , Sasaki Hiroshi , Arnarsson Arsaell , Sverrisson Thordur , Sasaki Kazuyuki , Stefánsson Einar ,   Reykjavik Eye Study Group
Published: March 2003

Purpose:  To establish a population profile of central corneal thickness (CCT), radius of the corneal curvature (CC) and intraocular pressure (IOP) and the relationships between them using non‐contact techniques.

Methods
:
We used a population‐based random sample of 415 male and 510 female Caucasians aged 50 years and older. CCT and the radius of CC were measured with Scheimpflug anterior segment photography. IOP was measured with air‐puff tonometry.

Results
:
The mean IOP of right eyes was 15.1 mmHg (SD 3.3) among men and 15.8 mmHg among women (SD 3.1), which is a statistically significant difference. The mean radius of CC for male right eyes was 7.78 (SD 0.60) and for females 7.62 (SD 0.58) which is also statistically significant. Mean CCT for male right eyes was 0.528 mm (SD 0.041) and for females 0.526 mm (SD 0.037), which is not a significant difference. Linear regression analysis shows no relationship between the radius of CC and IOP or between age and radius of CC. Linear regression analysis of the relationship between CCT and IOP suggests higher IOP measurements with thicker corneas. There was no significant correlation between age and CCT.

Conclusion
:
IOP was found to be independent of age and significantly higher in females than in males. Radius of CC was found to be age‐independent and significantly steeper in females than in males. CCT appears to be independent of age and gender. Greater CCT is associated with higher mean IOP.
Effect of brimonidine on patients undergoing uncontrolled IOP with beta‐blockers
Authors: Taverniti L. ,   S,   Donati, Di Staso S. , Arrico L. , Giuffrè I. , Recupero S. M.
Published: March 2003

The authors evaluated the effect of the replacement of β‐blockers with brimonidine drops in patients taking β‐blockers only or with dorzolamide, having IOP > 20 mmHg. The study was divided into two sections: one group treated with brimonidine b.i.d. (23 patients) and the other group treated with brimonidine + dorzolamide b.i.d. (17 patients). The effect of the substitution showed after 90 days of treatment with a reduction of 8.59 ± 1.2 mmHg (P < 0.001) in the first group and 6.1 ± 1.7 mmHg (P < 0.001) in the second group. Three patients in the first group and four patients in the second group presented minor adverse effects which did not justify discontinuation of treatment. Brimonidine was effective treatment as a substitute for β‐blockers only when associated with dorzolamide.
Prediction of violent recidivism
Authors: Stone M. H.
Published: March 2003

Objective:  To describe the changes and improvements in accuracy of the prediction of violent recidivism.

Method:  The evolution of better prediction models is described by reviewing the more significant methods used and referring to the results of their application.

Results:  Development of instruments such as the Psychopathy Checklist‐Revised, the Violence Risk Assessment Guide (VRAG), the HCR‐20 and the multiple‐item comprehensive questionnaire of Monahan and Steadman has substantially improved accuracy in risk assessment. The presence of full‐blown psychopathy has proven itself a better predictor of violence than has a diagnosis of antisocial personality disorder according to the Diagnostic and Statistical Manual (DSW‐IV). Shortcomings to the efficacy of the current instruments stem from the difficulty in detecting violence‐proneness in persons who eventually assault or murder one or two persons (usually family members), but who have no, or a limited, record of past violence. Persons from affluent backgrounds are more adept at evading arrests or convictions than are the poor. Adolescent sons abused by parents are at risk to commit violent acts later on, but the community has little power to detect or intervene until these acts are committed.

Conclusion:  Prediction of violence has significantly improved over the last 20 years, thanks to the development of objective instruments of risk assessment.