bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal migration of ITCZ precipitation across the equator: Why can't GCMs simulate it?
Authors: Wu Xiaoqing , Liang Xin‐Zhong , Zhang Guang Jun
Published: August 2003

The secondary meridional circulation induced by convective momentum transport (CMT) within the ascending branch of the Hadley circulation is a missing dynamical mechanism that can cause common failure of general circulation models (GCMs) in simulating seasonal migration of the intertropical convergence zone (ITCZ) precipitation maximum across the equator. This failure is manifested by the model bias that the precipitation peak remains north of the equator during November–March. The CMT‐induced secondary circulation, characterized by strong downward motion along the equatorial belt and upward motion south and north of the belt, tends to modify the meridional distribution of precipitation with the strongest impacts during boreal winter and spring. A 20‐year GCM simulation with the CMT parameterization successfully reproduces the observed seasonal migration of the ITCZ precipitation across the equator with the peaks near 8°N during boreal summer and near 8°S during boreal winter.
Solar wind electric field modulation of the NAO: A correlation analysis in the lower atmosphere
Authors: Boberg Fredrik , Lundstedt Henrik
Published: August 2003

Using geopotential height data we find a strong correlation between the electric field strength E of the solar wind and pressure variations in the stratosphere and troposphere. The large‐scale evolution of E seems to influence the stratospheric pressure in both hemispheres with the exception of the polar regions. For the tropospheric pressure the influence is concentrated to an area in the northern Atlantic. Using pressure and temperature data at sea level, we conclude that the correlation with E resembles the action of the North Atlantic Oscillation with an area with negative pressure correlation in the Arctic, an area with positive pressure correlation in the subtropics, an area with negative temperature correlation over Greenland and northeast Canada, and an area with positive temperature correlation over Europe.
Prediction of monthly‐seasonal precipitation using coupled SVD patterns between soil moisture and subsequent precipitation
Authors: Liu Yongqiang
Published: August 2003

It was suggested in a recent statistical correlation analysis that predictability of monthly‐seasonal precipitation could be improved by using coupled singular value decomposition (SVD) patterns between soil moisture and precipitation instead of their values at individual locations. This study provides predictive evidence for this suggestion by comparing skills of two statistical prediction models based on the coupled SVD patterns and local relationships. The data used for model development and validation are obtained from a simulation over East Asia with a regional climate model. The results show a much improved skill with the prediction model using the coupled SVD patterns. The seasonal prediction skill is higher than the monthly one. The most remarkable contribution of soil moisture to the prediction skill is found in warm seasons, opposite to that of sea surface temperature.
A decline in tropospheric organic bromine
Authors: Montzka S. A. , Butler J. H. , Hall B. D. , Mondeel D. J. , Elkins J. W.
Published: August 2003

Recent changes in atmospheric bromine (Br) are estimated from samples collected at ten globally distributed, ground‐based sites. The results indicate that the global tropospheric burden of Br from the sum of halons and methyl bromide (CH3Br) peaked in 1998 and has since declined by nearly 5% (or 0.8 ± 0.2 pmol mol−1 or ppt). These changes are driven primarily by a decrease of CH3Br since 1998 that is about two times larger than expected given reported declines in industrial production, a result that may suggest revisions to our understanding of the global atmospheric budget for this gas. The observations imply 25–30% larger declines in the atmospheric burden of ozone‐depleting, total equivalent chlorine (ECl = Cl + Br*45) in recent years than noted previously.
Sectors in the distant heliosphere: Voyager 1 and 2 observations from 1999 through 2002 between 57 and 83 AU
Authors: Burlaga L. F. , Ness N. F. , Richardson J. D.
Published: August 2003

Sectors and sector boundaries were observed by Voyager 1 (V1) and Voyager 2 (V2) from 1999 through 2002 in the distant heliosphere. V1 moved from a heliocentric distance R = 72.5 to 83.4 AU and from a latitude of δ = 33.4° to 33.8° from 1999.0 to 2002.0, and V2 moved from R = 56.7 to 69.0 AU and from δ = −20.2° to −24.1° from 1999.0 to 2003.0. During some time intervals, sectors were not present, and during much of the time the data were not sufficiently accurate to determine whether or not sectors were present. Nevertheless, some sectors do persist out to 83 AU, even in the interval surrounding the solar maximum. A regular sector pattern was not observed by either V1 or V2 in any of the years from 1999 through 2002. The sector sizes are highly variable, and they are not consistent with either a two‐sector pattern or a four‐sector pattern. The sector pattern observed at 1 AU by ACE was presumably destroyed by stream interactions and by transient ejecta that moved through the heliosphere. Observations of the solar wind speed made by V2 from 1999 to 2002 show a jump‐ramp structure, as expected from previous observational and theoretical studies. The jump‐ramp structures are much larger than the sectors. The speed jumps occur within some of the sectors, not at the sector boundaries.
Penetration of the heliosphere by the interstellar dust stream during solar maximum
Authors: Landgraf M. , Krüger H. , Altobelli N. , Grün E.
Published: August 2003

We analyze the Ulysses in situ measurements of interstellar dust in the solar system with respect to the temporal variation of the flux density. The data set that is used covers the time from after Ulysses' fly‐by of Jupiter up to the most recent data taken end of November 2002. The decrease in interstellar dust flux observed in 1996 can be explained by the interaction of the small, electrostatically charged grains with the solar wind magnetic field during the solar minimum with the polarity prevailing since 1991, as was reported earlier. Now with the new data, taken especially between 2000 and the end of 2002, we find that the amplitude of the decrease and the timing of the rebound with the 2000/2001 solar maximum is such that grains with relatively high charge to mass ratio of 1.33 C kg−1 and effective radii of 0.2 μm cannot account for the observed profile, as was concluded earlier. The simulation of the interaction of charged dust grains with the solar wind magnetic field shows that the best fit to the observations is achieved when the interstellar dust stream is dominated by grains with a charge to mass ratio of 0.59 C kg−1 and a radiation pressure efficiency factor of β = 1.1, which corresponds to an effective radius of 0.3 μm. We predict that the cumulative interstellar dust flux measured by Ulysses will level off at a constant value greater than 1 × 10−4 m−2 s−1 until the end of 2004.
Hydrogen atom lifetimes in the three‐dimensional heliosphere over the solar cycle
Authors: Pryor Wayne R. , Ajello Joseph M. , McComas David J. , Witte Manfred , Tobiska W. Kent
Published: August 2003

The three‐dimensional (3‐D) structure of the heliosphere is investigated using in situ and remote sensing measurements. The 3‐D structure of both neutral interplanetary gas and solar wind ions are affected by the solar latitude variation of the solar radiation fields (solar wind and solar EUV). Neutral hydrogen atom lifetimes against charge‐exchange with solar wind protons in the 3‐D heliosphere are calculated from measurements of the solar wind proton velocity, density, and mass flux by Ulysses SWOOPS (Solar Wind Observations Over the Poles of the Sun) from 1990–2001. These are compared to in‐ecliptic H atom lifetimes derived from solar wind measurements by the spacecraft IMP (Interplanetary Monitoring Platform) 6, 7, and 8, WIND, and ACE (Advanced Composition Explorer) SWEPAM (Solar Wind Electron Proton Alpha Monitor). Recent observations during the Ulysses rapid solar pole‐to‐solar pole passage (fast‐latitude scan) at solar maximum find a more isotropic rotationally averaged solar wind mass flux (and H atom lifetime) than was found during the previous fast latitude scan at solar minimum. During the solar minimum fast‐latitude scan the 27‐day averaged SWOOPS lifetime passed through two distinct regimes: it doubled from 2 × 106 s at low latitudes to 4 × 106 s at high latitudes in both hemispheres. During the solar maximum pass the 27‐day averaged SWOOPS H atom lifetime (corrected to 1 AU) at all southern latitudes and at all northern latitudes below 60° was (2–2.5) × 106 s, while at the very end of the pass, above 60° N latitude, it rose to 4 × 106 s as polar coronal holes reformed. Remote sensing studies of interplanetary H Lyman‐α emission, white light solar coronal observations, and radio scintillation experiments have also indicated that the time‐averaged solar wind mass flux (and H atom lifetime) is more isotropic at solar maximum than at solar minimum. This enlarges the polar H cavity at solar maximum. Results from in situ measurements are compared to remote sensing data. Ulysses GAS Lyman‐ α maps are modeled, with updated results. Comparisons of the H atom charge exchange loss rate with a weaker H atom loss process, photoionization, are made using the SOLAR2000 model [Tobiska et al., 2000] for in‐ecliptic solar Extreme UltraViolet (EUV) fluxes. The relative latitude invariance of the H atom lifetime at solar maximum is related to the absence of high‐speed solar wind at solar maximum and to the large inclination of the heliospheric current sheet.
Intravenous clonidine prolongs bupivacaine spinal anesthesia
Authors: Rhee K. , Kang K. , Kim J. , Jeon Y.
Published: August 2003

Background:  Prolongation of spinal anesthesia by oral clonidine premedication has been known. We hypothesized that intravenous clonidine administered after the spinal block may prolong spinal anesthesia.

Methods:  To assess the prolongation of spinal anesthesia by intravenous clonidine, we designed a double‐blind, placebo‐controlled, prospective study. Patients scheduled for orthopedic surgery received 12 mg of 0.5% hyperbaric bupivacaine and were randomly divided into three groups (n = 26 in each group). In the clonidine 10‐min group, 3 µg kg−1 of clonidine was administered for 10 min immediately after the spinal block. In the clonidine 60‐min group, 3 µg kg−1 of clonidine was administered for 10 min, 50 min after the spinal block. The control group received normal saline. Sensory block was evaluated by pinprick and the duration was defined as the time for sensory block to regress to L1 dermatome. Duration of motor block was defined as the time required for the patient to flex his or her knee.

Results:  The duration of sensory block was longer in both the clonidine 10‐min and clonidine 60‐min groups compared with the control group (196 ± 42 min, 179 ± 41 min vs. 125 ± 25 min, P < 0.05). The duration of motor block was longer in the clonidine 10‐min group than in the control group (153 ± 26 min vs. 131 ± 29 min, P < 0.05). The lowest heart rate and mean blood pressure were not different among groups.

Conclusions:  Intravenous clonidine administration within 1 h after the spinal block prolonged bupivacaine spinal anesthesia for approximately 1 h without adverse effects.
Relaxing intraoperative natural sound blunts haemodynamic change at the emergence from propofol general anaesthesia and increases the acceptability of anaesthesia to the patient
Authors: Tsuchiya M. , Asada A. , Ryo K. , Noda K. , Hashino T. , Sato Y. , Sato E. F. , Inoue M.
Published: August 2003

Background:  It is known that auditory input, such as comforting music or sound, blunts the human response to surgical stress in conscious patients under regional anaesthesia. As auditory perception has been demonstrated to remain active under general anaesthesia, playing comforting sounds to patients under general anaesthesia might also modulate the response of these patients to surgical stress.

Methods:  Fifty‐nine patients scheduled for laparoscopic cholecystectomy were anaesthetized with propofol general anaesthesia in combination with epidural anaesthesia. Natural sounds, chosen preoperatively by each patient as being comforting, were played to 29 patients using headphones during surgery (S group) and the remainder of the patients (n = 30) were fitted with dummy open‐type headphones (N group). We compared the haemodynamic change during anaesthesia and the acceptability of anaesthetic practice between the two groups in a randomized double‐blind design.

Results:  There were no differences in haemodynamics between the S and N groups during surgery. During the emergence from anaesthesia, the mean blood pressure and heart rate gradually increased; both parameters were significantly higher in the N group than in the S group. Postoperatively, patients in the S group perceived the experience of anaesthesia as significantly more acceptable than did those in the N group.

Conclusion:  These findings indicate that allowing patients comforting background sounds during general anaesthesia may blunt haemodynamic changes upon emergence from general anaesthesia and increase the acceptability of the experience of anaesthesia.
Differential presentation of post tracheostomy bleeding: a case series
Authors: Ong G. K. S. , Cheng C. J. C. , Ang S. T. C. , Ng H. N. , Chee H. L.
Published: August 2003

The relief of upper airway obstruction is one of the indications for tracheostomy. However, this procedure is not without its complications. We present a case series where post tracheostomy bleeding results in life‐threatening sequelae in the form of torrential haemorrhage and sudden airway obstruction from clot. The latter presentation can present a diagnostic conundrum that could prove fatal if not rapidly identified.
Between Scylla and Charybdis: A bleomycin‐exposed patient with Cohen syndrome
Authors: Orbach‐Zinger S. , Kaufman E. , Donchin Y. , Perouansky M.
Published: August 2003

Chemotherapy with bleomycin may cause a syndrome of pulmonary sensitivity to supranormal inspired oxygen concentrations that persists for an unknown period of time after exposure. We present a mentally retarded adolescent patient in whom supranormal inspired oxygen was temporarily necessary to manage her difficult airway. Subsequently her pulmonary function deteriorated acutely and, after intermittent stabilization, irreversibly. In this case, bleomycin exposure may have played a pivotal role in modulating minor insults to trigger fatal acute respiratory distress syndrome (ARDS).
Tramadol encapsulated into polyhydroxybutyrate microspheres: in vitro release and epidural analgesic effect in rats
Authors: Salman M. A. , Sahin A. , Onur M. A. , Öge K. , Kassab A. , Aypar Ü.
Published: August 2003

Background:  Controlled release techniques are used to increase the duration of action and decrease the toxicity of drugs. Any controlled release form of tramadol in spinal or epidural blocks has not been studied previously. Tramadol was encapsulated into polyhydroxybutyrate (PHB) microspheres and release kinetics was studied. The epidural analgesic effect of this solution in rats was also compared with free tramadol.

Methods:  Controlled release of tramadol from PHB microspheres into 10 ml of phosphate buffer solution at pH 7.4 and 37 °C was studied in vitro. In vivo studies were performed in 40 rats. Epidural catheters were placed during general anaesthesia. Rats were randomly allocated into one of the four study groups to receive normal saline, 4 mg of tramadol, PHB microspheres without tramadol, or 4 mg of tramadol encapsulated into PHB microspheres. Analgesia was evaluated with tail flick tests performed at 52.5 ± 0.5 °C before injection and at intervals up to 30 h after injection. Catalepsy and loss of corneal reflexes were considered as signs of supraspinal toxicity.

Results:  In vitro drug release was observed for more than 6 days. Epidural analgesic effects of tramadol released from PHB microspheres were observed for 21 h, whereas an equal dose of free tramadol was effective for less than 5 h. No signs of toxicity were observed.

Conclusion:  Controlled release of tramadol from PHB microspheres is possible, and pain relief during epidural analgesia is prolonged by this drug formulation compared with free tramadol.
Severe intoxication after an intentional overdose of amlodipine
Authors: Rasmussen L. , Husted S. E. , Johnsen S. P.
Published: August 2003

Intoxication with 280 mg of amlodipine caused severe hypotension, third‐degree heart block and hyperkalaemia in a 36‐year‐old female patient. The patient was initially treated with fluids, dopamine, calcium chloride, and epinephrine without effect. The patient was then given a bolus injection of insulin and glucose as a temporary mean to treat the hyperkalaemia. We observed a rise in blood pressure (BP) after insulin was given and the BP was subsequently responsive to epinephrine. A possible positive inotropic effect of insulin therapy in patients with calcium channel blocker intoxication is in accordance with previous findings. In conclusion, it is suggested that hyperinsulinaemia‐euglycaemia therapy may be considered as a first‐line therapy in calcium channel blocker intoxication.
Automated responsiveness test and bispectral index monitoring during propofol and propofol/N2O sedation
Authors: Doufas A. G. , Bakhshandeh M. , Haugh G. S. , Bjorksten A. R. , Greif R. , Sessler D. I.
Published: August 2003

Background:  Sedation practice, especially when non‐anaesthesia personnel are involved, requires efficient anaesthetic depth monitoring. Therefore, we used prediction probability (PK) to evaluate the performance of the bispectral index (BIS) of the EEG and automated responsiveness test (ART) to predict sedation depth and loss of subject's responsiveness during propofol sedation, with and without N2O.

Methods:  Twenty volunteers were studied during propofol administration with (N2O) and without (Air) N2O. The protocol consisted of sequential 15‐min cycles. After a control period, propofol was infused to a target effect‐site concentration of 0.25 µg/ml (N2O) or 1.5 µg/ml (Air), which was subsequently increased by 0.25 or 0.5 µg/ml, respectively, until loss of responsiveness was detected by loss of response to command [observer's assessment of alertness/sedation (OAA/S) score ≤ 2].

Results:  Deeply sedated patients did not respond to ART indicating that the sensitivity was 1.0 with or without N2O. The specificity of ART was 0.24 with Air and 0.98 with N2O. The BIS was better than ART in predicting OAA/S score (PK = 0.84 vs. 0.77) and loss of responsiveness (PK = 0.87 vs. 0.69) during the Air trial. Nitrous oxide decreased the performance of BIS in predicting OAA/S score (PK = 0.76), but increased the performance of ART to predict loss of responsiveness (PK = 0.85).

Conclusion:  BIS and ART comparably predict sedation and loss of responsiveness. However, ART, because of its resistance to false‐normal responses, might prove to be more useful on an individual patient basis – especially in the presence of agents that impair BIS sensitivity.
Ephedrine in the cat lung vasculature
Authors: Fields A. M. , Richards T. A. , Ibrahim I. N. , Kaye A. D.
Published: August 2003

Background:  Ephedrine is one of the most commonly used non‐catecholamine sympathomimetic agents. It is used in operating rooms and critical care settings worldwide. While it has many side effects, its ability to rapidly raise blood pressure makes it an ideal agent to maintain homeostasis as well as in emergency situations. While its effects are known to be mediated by an α‐mediated mechanism, the exact α subtype is unknown. In addition, no studies using ephedrine have been performed in the pulmonary vascular bed of the cat.

Methods:  The effects of phentolamine, a non‐selective α‐receptor blocker, and prazosin, an α1‐selective antagonist, were investigated on pulmonary arterial responses to ephedrine, phenylepherine, norepinephrine, and U‐46619. Lobar arterial perfusion pressure was continuously monitored, electronically averaged, and recorded with constant flow in the isolated left lower lobe vascular bed of the cat.

Results:  Phentolamine and prazosin significantly reduced vasoconstrictor pulmonary perfusion pressure increases induced by ephedrine.

Conclusion:  Ephedrine has significant vasopressor activity in the pulmonary vascular bed of the cat meditated predominantly by α1 adrenergic receptor activation.
Successful off pump coronary artery bypass grafting in a patient with an undiagnosed pheochromocytoma
Authors: Sartipy U. , Lindvall G. , Van Der Linden J. , Dellgren G.
Published: August 2003

We report a successful off pump coronary artery bypass case in a patient with a pre‐operatively undiagnosed pheochromocytoma. The patient had no signs of ischemia intra‐ or post‐operatively due to aggressive antihypertensive treatment. We would also like to emphasize the importance of using an adequate stabilizing device in order to safely perform anastomoses in a situation like this.
The psychometric properties of Chinese pain intensity verbal rating scale
Authors: Liu J. Y. W. , Chung J. W. Y. , Wong T. K. S.
Published: August 2003

Background:  This study investigates the validity and reliability of the Chinese pain intensity verbal rating scale (C‐PIVRS).

Methods:  This is a correlational comparative study. Fifty Chinese adults were recruited by convenience. A pain source generator (precision pain source, PPS‐3) was used to produce four levels of mechanical pain stimuli (350, 550, 750 and 950 g). The pain stimuli were applied to subjects' interphalangeal joints in random sequences to stimulate sensation of pain. The subjects then rated their pain intensity using both the C‐PIVRS and the visual analog scale (VAS) for each stimulus. The pain scores obtained from the C‐PIVRS were compared with the VAS for satisfactory level of reliability and validity. Test and re‐test were applied to verify consistency between the two pain scales.

Results:  The test/re‐test correlation coefficients between the two pain scales were r = 0.92 (P < 0.001) and r = 0.91 (P < 0.001), respectively. This showed a good positive correlation. The intra‐class correlation (ICC) ranged from 0.78 to 0.90, which indicated good reliability. In the factor analysis, a single factor emerged in each analysis. The first eigen values of each matrix were 3.42, 3.24, 3.17 and 3.29 for each level of pain stimulation. This indicated that both pain scales were assessing the same pain dimension.

Conclusions:  The two pain scales have a comparable level of reliability and validity for assessing pain intensity in Chinese adults.
Neuroleptic malignant syndrome with severe liver failure
Authors: Urving S. H. , Nielsen E. W.
Published: August 2003

A schizophrenic patient on long‐time neuroleptic medication was admitted with ileus. Secondarily, a high fever, rigidity, mental confusion, tachycardia and hypotension developed. After bromocriptine was given, the temperature dropped by 2°C and the patient improved markedly. A diagnosis of neuroleptic malignant syndrome was made. Five years later she was re‐admitted with similar symptoms and also severe liver failure. Meanwhile the discontinued neuroleptic medication had been reinstituted. Again bromocriptine reduced the temperature of approximately 2°C, and was paralleled by a normalization of liver function. To our knowledge this is the second report on severe liver failure in conjunction with neuroleptic malignant syndrome. The efficacy of bromocriptine in the treatment of this syndrome is underlined.
Sevoflurane: an ideal agent for adult day‐case anesthesia?
Authors: Ghatge S. , Lee J. , Smith I.
Published: August 2003

Sevoflurane has several properties which make it potentially useful as a day case anaesthetic. Following induction of anaesthesia with propofol, awakening from sevoflurane is faster compared to isoflurane, faster or similar compared to propofol and comparable (in the majority of studies) to desflurane. Subsequent recovery and discharge is generally similar following all agents. Sevoflurane may also be used to induce anaesthesia, which is generally well‐received and causes less hypotension and apnoea compared to propofol.

When used as a maintenance anaesthetic, the incidence of postoperative nausea and vomiting after sevoflurane is comparable to other inhaled anaesthetics, but this complication appears more common after inhaled inductions. The tolerability and low solubility of sevoflurane facilitate titration of anaesthesia and may reduce the need for opioid analgesia, which in turn may limit the occurrence of nausea and vomiting.
Effects of 0.5 and 1.0 MAC isoflurane, sevoflurane and desflurane on intracranial and cerebral perfusion pressures in children
Authors: Sponheim S. , Skraastad Ø. , Helseth E. , Due‐Tønnesen B. , Aamodt G. , Breivik H.
Published: August 2003

Background:  Isoflurane has been a commonly used agent for neuroanesthesia, but newer agents, sevoflurane and desflurane, have a quicker onset and shorter emergence from anesthesia and are increasingly preferred for general pediatric anesthesia. But their effects on intracranial pressure (ICP) and cerebral perfusion pressure (CPP), especially in pediatric patients with already increased ICP, have not been well documented.

Methods:  We studied 36 children scheduled for elective implantation of an intraparenchymal pressure device for 24 h monitoring for suspected elevated ICP. After a standardized intravenous anesthesia, the patients were moderately hyperventilated with 60% nitrous oxide (N2O) in oxygen. The patients were then randomized to receive 0.5 and 1.0 MAC of isoflurane (Group I, n = 12), sevoflurane (Group S, n = 12) or desflurane (Group D, n = 12) in 60% N2O in oxygen. Respiratory and hemodynamic variables, ICP and CPP were recorded at baseline and after exposure to a target level of test drug for 10 min or until CPP fell below 30 mmHg (recommended lower ICP level is 25 mmHg in neonates, rising to 40 mmHg in toddlers).

Results:  When comparing baseline values with values at 1.0 MAC, mean arterial pressure (MAP) decreased (P < 0.001) in all groups, with no differences between the groups. ICP increased (P < 0.001) with all agents, mean +2, +5, and +6 mmHg in Group I, S and D, respectively, with no differences between the groups. Regression analyzes found no relationship between baseline ICP and the increases in ICP from baseline to 1.0 MAC for isoflurane or sevoflurane. However, increased baseline ICP tended to cause a higher ICP increase with 1.0 MAC desflurane; regression coefficient +0.759 (P = 0.077). The difference between regression coefficients for Group I and Group D were not significant (P = 0.055). CPP (MAP‐ICP) decreased (P < 0.001) in all groups, mean −18, −14 and −17 mmHg in Group I, S and D, respectively, with no significant difference between the groups.

Conclusions:  0.5 and 1.0 MAC isoflurane, sevoflurane and desflurane in N2O all increased ICP and reduced MAP and CPP in a dose‐dependent and clinically similar manner. There were no baseline dependent increases in ICP from 0 to 1.0 MAC with isoflurane or sevoflurane, but ICP increased somewhat more, although statistically insignificant, with higher baseline values in patients given desflurane. The effect of MAP on CPP is 3–4 times higher than the effect of the increases in ICP on CPP and this makes MAP the most important factor in preserving CPP. In children with known increased ICP, intravenous anesthesia may be safer. However, maintaining MAP remains the most important determinant of a safe CPP.
Serious overdoses involving buprenorphine in Helsinki
Authors: Boyd J. , Randell T. , Luurila H. , Kuisma M.
Published: August 2003

Background:  Buprenorphine is used as maintenance therapy for opioid‐dependent patients. In comparison with other opioids it is thought to be safer because it is less likely to cause serious respiratory depression. However, concomitant use of psychotropics, especially benzodiazepines, and intravenous injection of dissolved buprenorphine tablets increase the risk of a serious overdose.

Methods:  As part of a larger retrospective study of opioid overdoses in Helsinki, the emergency medical services (EMS) records from January 1995 to April 2002 were reviewed for overdoses involving buprenorphine. Hospital records were reviewed when available.

Results:  We report 11 overdoses in which buprenorphine was involved. The classic symptoms and signs of an opioid overdose (respiratory depression, miosis and central nervous system depression) were present in most of the cases. At least eight of the patients had an overdose that was potentially fatal. One of the patients had a heroin overdose and was reportedly ‘treated’ by his friends with intravenously administered buprenorphine.

Conclusion:  The high‐dosage formulation of buprenorphine used for opioid‐dependent patients might have caused several dangerous and potentially fatal overdoses in Helsinki. However, it does cause considerably less serious overdoses than heroin. Drug abusers might be intravenously administering buprenorphine themselves to treat heroin overdoses.
A lung recruitment maneuver immediately before rescue surfactant therapy does not affect the lung mechanical response in immature lambs with respiratory distress syndrome
Authors: Ingimarsson J. , Björklund L. J. , Curstedt T. , Larsson A. , Robertson B. , Werner O.
Published: August 2003

Background:  In animals with acquired surfactant‐deficiency, a recruitment maneuver by increased tidal volumes enhances the effect of exogenous surfactant. In contrast, in the preterm lamb model, hyperinflation early after birth impairs the effect of surfactant prophylaxis. Here we examined whether a lung recruitment maneuver just before surfactant would affect the response to rescue treatment in immature lambs with established respiratory distress syndrome (RDS).

Methods:  Five pairs of preterm twin lambs with gestational age 127 days were delivered by cesarean section and supported by pressure‐limited mechanical ventilation for 4 h. At 30 min of age, when all the lambs were in severe respiratory failure, they were treated with porcine surfactant, 200 mg kg−1. One lamb in each pair was subjected to a lung recruitment maneuver consisting of five sustained inflations of 20 ml kg−1 just before surfactant instillation.

Results:  At 10 min after surfactant treatment, all the lambs showed a large improvement in oxygenation and an increase in inspiratory capacity and static compliance. Except for a transiently better oxygenation after surfactant therapy in the recruitment group (P < 0.05), there was no significant between‐group differences in gas exchange or lung mechanics at any time point during the study. There was no difference in post mortem intrapulmonary air volume or alveolar expansion in histologic lung sections between groups.

Conclusion:  This small study does not show any positive or negative effect of a lung recruitment maneuver on the response to rescue surfactant therapy in immature animals with RDS.
Computerized quality assurance of decisions to transfuse blood components to critically ill patients
Authors: Pentti J. , Syrjälä M. , Pettilä V.
Published: August 2003

Background:  In critically ill patients optimal transfusion therapy for most clinical settings has not been determined. The objective of this study was to evaluate the impact of a computerized audit on transfusion decisions of red blood cells (RBC), fresh frozen plasma (FFP), and platelets among critically ill patients.

Methods:  Two hundred and ninety consecutive patients admitted to nine‐bed medical‐surgical intensive care unit at a university hospital were included in this prospective study. Prior to the study, the criteria for transfusions of RBCs, FFP and platelets were established. Phase I, the first 3‐month period served as a control period. During phase II the fulfilment of these criteria was prospectively monitored by an audit software belonging to the computerized blood request program. If the predefined transfusion criteria were not met the audit software was automatically activated. The last 3‐month period, phase III, was to assess if possible effects on transfusion decisions were permanent.

Results:  The proportion of RBC transfusions administered according to predefined trigger during the study phases I, II, and III were 55.9%, 75.1% and 67.9%, respectively (P < 0.001). The proportion of FFP and platelet transfusions according to a predefined trigger did not differ statistically significantly between the study phases. Logistic multiple regression analysis revealed an independent effect of the audit phase on the decision to transfuse RBCs and FFP.

Conclusions:  The data suggests that a computerized prospective transfusion audit has impact on the realisation of predefined transfusion decisions.
Pharmacological modulation of experimental phasic and tonic muscle pain by morphine, alfentanil and ketamine in healthy volunteers
Authors: Schulte H. , Graven‐Nielsen T. , Sollevi A. , Jansson Y. , Arendt‐Nielsen L. , Segerdahl M.
Published: August 2003

Background:  Muscle pain is a major clinical problem but the underlying mechanisms and its pharmacological modulation need further investigation. This study on 15 volunteers evaluates if two experimental muscle pain models are sensitive to µ‐receptor agonists and to an N‐methyl‐D‐aspartate (NMDA)‐receptor antagonist.

Methods:  In the left tibialis anterior, intramuscular electrical (IMES) pain thresholds were determined for single (SPTmuscle) and five (RPTmuscle) repeated stimuli. Also pain to suprathreshold stimulation at 150% of RPTmuscle, 10 s, was assessed on a visual analog scale (VAS) as AUCimes (area under the VAS curve). In the right TA muscle, pain intensity on infusion of 0.5 ml of hypertonic saline, 5% (AUCsaline) and pain distribution indicated as local and referred were evaluated. Pain variables were assessed before, during and after intravenous infusions of morphine (10 µg kg−1 min−1, 10 min), alfentanil (target‐controlled infusion, plasma concentration; 60 ng ml−1, 60 min) and ketamine (10 µg kg−1 min−1, 60 min). All data were normalized to baseline pain values (before drug infusions were initiated) and compared with placebo (midazolam, 2 µg kg−1 min−1, 10 min).

Results:  SPTmuscle increased (log mean values  ±  SD, mA) with morphine (0.11 ± 0.17, P < 0.05), alfentanil (0.28  ±  0.24, P < 0.001) and ketamine (0.19  ±  0.18, P < 0.01) as compared with placebo (−0.03  ±  0.12). Alfentanil and ketamine also increased RPTmuscle (0.25  ±  0.21, P < 0.01 and 0.21  ±  0.19, P < 0.05, respectively) as compared with placebo (0.00  ±  0.17). Pain to IMES (AUCimes) was reduced (median values [25th−75th percentiles], cm × s) by alfentanil and ketamine (−19.7 [−14.6 – −29.6] and−12.8 [−8.3 – −27.8], P < 0.05, respectively) vs. placebo (−0.8 [1.6 – −12.3]). Similar drug effects were seen when pain to infusion of hypertonic saline (AUCsaline) was assessed (alfentanil:−388 [−99 – −677] and ketamine:−326 [−227 – −573], P < 0.05 compared with placebo: 150 [449–−240]). Ketamine also reduced the size of the local pain area (−58.4 [−21.2 – −176.1],  < 0.05) as compared with placebo (−0.4 [70.6 – −13.4]). The frequency of referred pain was also lower when ketamine was given (3/13, P < 0.05) vs. placebo (9/14).

Conclusion:  The study demonstrates that experimental muscle pain induced in humans by electrical stimulation and infusion of hypertonic saline is sensitive to pharmacological modulation similar to preclinical animal tests and clinical trials. The data suggest that these models can be valuable tools in analgesic drug development.
A study on the microheterogeneity of alpha‐fetoproteins produced by yolk sac and germ cell tumors
Authors: Yamamoto Ritsu , Ohkouchi Toshihiro , Wakui Yukio , Minobe Shinichiro , Watari Hidemichi , Shimizu Kayoko , Satomura Shinji , Sakuragi Noriaki
Published: August 2003

Background.  It is generally believed that the lower the grade of differentiation of glycoprotein‐producing cells, the more often modification by bisecting N‐acetylglucosamine (GlcNAc) or fucose (Fuc) at the sugar chain of the glycoprotein or increase in branching of side chains occurs. We examined the characteristics of the alpha‐fetoprotein (AFP) sugar chain stored in amniotic and exocoelomic fluid during 5–9 weeks of gestation and analyzed serum‐derived AFP of patients with germ cell tumors.

Methods.  Total AFP concentrations in embryonic fluid at 5–9 weeks of gestation (n = 11) and serum of patients with germ cell tumors (n = 7) were measured using a radioimmunoassay (RIA) method. The percentages of AFPs reactive with Lens culinaris agglutinin (LCA), concanavalin A (Con A), erythroagglutinating phytohemagglutinin‐E4 (E‐PHA) and Ricinus communis agglutinin‐120 (RCA 120) were obtained by lectin‐affinity electrophoresis coupled with antibody‐affinity blotting.

Results.  It was revealed that at 5–9 weeks of gestation, AFP variants that had been modified by the Fuc residue, which bound to the GlcNAc residue at the reducing end of the sugar chain, and bisecting GlcNAc residues gradually decreased as pregnancy advanced; however, the presence of N‐acetylneuraminic acid (Neu5Ac) at the nonreducing ends changed little.

Conclusions.  It appears very likely that the changes in the relative amounts of AFP variants in the embryonic fluid during early pregnancy were due to differentiation of the yolk sac. The grade of differentiation of yolk sac tumors was very similar to that of the normal yolk sac at around 6 weeks of gestation.
Effect of combined oral estrogen/progestogen preparation (Kliogest®) on bone mineral density, plasma lipids and postmenopausal symptoms in HRT‐naïve Thai women
Authors: Jirapinyo Mayuree , Theppisai Urusa , Manonai Jittima , Suchartwatnachai Charnchai , Jorgensen Lars Nelleman
Published: August 2003

Background.  Kliogest® is commonly prescribed for the relief of acute postmenopausal symptoms and prevention of postmenopausal bone loss. However, there have been few data on its effect in Asian women.

Methods.  This 1‐year, single‐center, randomized, double‐blind and placebo‐controlled study evaluated the efficacy and safety of Kliogest® in hormone replacement therapy (HRT)‐naïve Thai women. The subjects were 120 healthy Thai women aged between 45 and 65 years, with intact uterus, and who had been amenorrheic for at least 1 year.

Results.  Kliogest® increased spine (+ 6%, p < 0.01) and hip (+2%, p < 0.01) bone mineral density (BMD), and lowered plasma total cholesterol (TC) (−16%, p < 0.05) and low density lipoprotein cholesterol (LDL‐C) (−16%, p < 0.05) concentrations. However, Kliogest® also resulted in a decrease in high density lipoprotein cholesterol (HDL‐C) concentration (−18%, p < 0.05). Compared to placebo, the reduction in menopausal symptoms by Kliogest® was not statistically significant. The frequency and severity of treatment‐related uterine bleeding decreased with the duration of Kliogest® treatment. Furthermore, there was a fairly strong relationship between the change in serum estrone concentration and the average monthly weighted bleeding scores over the first 6 months (Spearman's correlation r = 0.54; p < 0.001), which became weaker over the entire treatment period (Spearman's correlation r = 0.27; p < 0.01). Although there was a small to moderate relationship between baseline estrone concentration and both lumbar (r = 0.23, p < 0.02) and hip (r = 0.20, p < 0.05) BMD, there was no significant relationship between Kliogest®‐induced change in estrone concentration and change in lumbar and hip BMD.

Conclusions.  Continuous treatment with Kliogest® for 1 year reversed the potential postmenopausal bone loss in HRT‐naïve Thai postmenopausal women. However, its effect on cardiovascular risk is uncertain. Furthermore, Kliogest® is safe but appears to have no significant effect on climacteric symptoms in the patients in the present study.
Experiences with fetomaternal alloimmune thrombocytopenia at a Swedish hospital over a 10‐year period
Authors: Tiblad Eleonor , Olsson Ingeborg , Petersson Karin , Shanwell Agneta , Winiarski Jacek , Wolff Kerstin , Westgren Magnus
Published: August 2003

Background.  This is a descriptive study of the management and outcome of 18 cases of fetomaternal alloimmune thrombocytopenia (FMAIT) treated from 1991 to 2001.

Material and methods.  Management of the disease changed over the years from cordocentesis in the 20–24th week of gestation, platelet transfusions and immunoglobulin to a less invasive management consisting of only blind administration of immunoglobulin and predelivery cordocentesis.

Results.  Three of the fetuses were treated with intrauterine platelet transfusions. Two of these were delivered by emergency cesarean section due to failed transfusions and the third fetus died as a result of the procedure. Nine mothers were treated with immunoglobulin intravenously. Four of these delivered thrombocytopenic children. Three women did not want to undergo any treatment, and all newborns had low platelet counts. Two fetuses died, one in conjunction with a platelet transfusion and the other in utero before treatment was commenced. All the other children did well despite the fact that some of them were severely thrombocytopenic at birth.

Conclusions.  Due to the limited number of patients, the present material does not allow any far reaching conclusions. Our experience is that a non‐invasive management can be practiced in cases of FMAIT. The value of performing cordocentesis and platelet transfusions in the second trimester is doubtful in view of the risk for the fetus and the limited amount of information it provides for management of the individual case.
Elective cesarean section vs. spontaneous delivery: a comparative study of birth experience
Authors: Schindl Monika , Birner Peter , Reingrabner Michaela , Joura Elmar A. , Husslein Peter , Langer Martin
Published: August 2003

Background.  To investigate birth experience and medical outcome in women with elective cesarean section (CS) compared with women with intended vaginal delivery.

Methods.  A total of 1050 pregnant women were included in this prospective trial. Psychological factors, pain levels and birth experience were investigated using a self‐designed questionnaire and three established psychological tests in gestational week 38, and 3 days and 4 months postpartum. In addition, medical data were evaluated from the records.

Results.  Out of 903 women with planned vaginal birth, in 484 women (53.6%) minimal perineal surgery had to be performed after birth, 41 women (4.5%) had vacuum deliveries, and in 93 cases (10.3%) emergency CS had to be performed. In the 147 elective CS (103 based on medical and 44 on psychological factors), a significantly lower rate of maternal and fetal complications was observed when compared with vaginal birth (5.4% vs. 19.3%; p < 0.0001). Birth experience (Salmon test) was significantly better in elective CS compared with vaginal delivery, but worse in women with emergency CS and worst in those with vacuum delivery. We found that 83.5% of women with vaginal delivery would choose the same mode of birth again, 74.3% of women with CS on demand, and 66% of women with medically necessary CS. Only 30.1% of women with emergency CS wanted to receive CS at the next birth.

Conclusions.  Elective CS is a safe and psychologically well tolerated procedure. The results are comparable with uncomplicated vaginal delivery and far superior to secondary intervention such as vacuum delivery or emergency CS.
Comparison of the response to ovarian stimulation between women with one ovary and those with two ovaries, in a program of ICSI/ET
Authors: Al‐Hasani Safaa , Asimakopoulos Byron , Nikolettos Nikos , Diedrich Klaus
Published: August 2003

Background.  Women with a single ovary form a group of special interest in assisted reproduction. The aim of this study was to compare the outcome of intracytoplasmic sperm injection cycles between women with one and two ovaries. To our knowledge, this is the first study reporting the outcome of intracytoplasmic sperm injection cycles with women with a single ovary.

Methods.  Sixty‐three intracytoplasmic sperm injection cycles in 24 women with a single ovary were compared with 191 intracytoplasmic sperm injection cycles in 109 women with both ovaries. All cycles were stimulated with triptorelin‐long protocol.

Results.  Statistically significant differences were found in the following parameters between women with a single ovary and women with two ovaries: total number of administrated gonadotropins (63.22 ± 45.03 vs. 44.72 ± 21.92), number of follicles (8.29 ± 5.02 vs. 14.45 ± 7.94), estradiol peak levels (1695.05 ± 1177.34 vs. 2728.51 ± 1852.67), number of retrieved metaphase II oocytes (6.95 ± 3.78 vs. 11.72 ± 6.11) and number of 2 PN oocytes (4.07 ± 2.85 vs. 6.53 ± 4.14). There were no differences in duration of stimulation, number of transferred embryos, and cumulative embryo score. In the group of women with a single ovary 14 pregnancies were achieved (22.2%), whereas 33 pregnancies were achieved in the group of women with two ovaries (17.28%).

Conclusions.  Women with a single ovary have a decreased response to external ovarian stimulation than women with both ovaries, but they present a higher, although not statistically significant, pregnancy rate.
New score indicating placental vascular resistance
Authors: Gudmundsson Saemundur , Korszun Przemyslaw , Olofsson Per , Dubiel Mariusz
Published: August 2003

Background.  Umbilical artery Doppler velocimetry is a routine method for fetal surveillance in high‐risk pregnancy. Uterine artery Doppler seems to give comparable information, but it can be difficult to interpret as there are two arteries, which might show notching and/or increased pulsatility index (PI) as signs of increased vascular impedance. Combining the information on vascular resistance on both sides in a new score might simplify and improve evaluation of placental circulation.

Methods.  Uterine and umbilical artery Doppler velocimetry was evaluated in 633 high‐risk pregnancies. The managing clinician was informed only about the umbilical artery flow. The umbilical artery flow spectrum was semiquantitatively divided into four blood flow classes (BFC), expressing signs of increasing vascular resistance. The uterine artery Doppler flow spectrum was divided into five uterine artery scores (UAS), taking into account presence/absence of notching and/or increase in PI. By adding UAS to BFC, a new placental score (PLS) was constructed with values ranging from 0 to 7, indicating general placental vascular resistance. The scores were related to three outcome variables: small‐for‐gestational age (SGA), premature delivery (<37 weeks), and cesarean section.

Results.  All three score systems showed a significant relationship between signs of increasing vascular resistance and outcome. The new PLS showed the best association to adverse outcomes, with optimal cut‐off at values exceeding score 3.

Conclusion.  Doppler velocimetry on both sides of the placenta showed a strong relationship to an adverse outcome of pregnancy. The new PLS showed a better relationship to adverse perinatal outcome than the BFC and the UAS. The PLS can simplify evaluation of uteroplacental and fetoplacental Doppler velocimetry.