Laser Wakefield Driven Generation of Isolated Carrier-Envelope-Phase Tunable Intense Subcycle Pulses

Sources of intense, ultrashort electromagnetic pulses enable applications such as attosecond pulse generation, control of electron motion in solids, and the observation of reaction dynamics at the electronic level. For such applications, both high intensity and carrier-envelope-phase (CEP) tunability are beneficial, yet hard to obtain with current methods. In this Letter, we present a new scheme for generation of isolated CEP tunable intense subcycle pulses with central frequencies that range from the midinfrared to the ultraviolet. It utilizes an intense laser pulse that drives a wake in a plasma, copropagating with a long-wavelength seed pulse. The moving electron density spike of the wake amplifies the seed and forms a subcycle pulse. Controlling the CEP of the seed pulse or the delay between driver and seed leads to CEP tunability, while frequency tunability can be achieved by adjusting the laser and plasma parameters. Our 2D and 3D particle-in-cell simulations predict laser-to-subcycle-pulse conversion efficiencies up to 1%, resulting in relativistically intense subcycle pulses.

A randomized, single-blind, increasing dose safety trial of an oxygen-carrying plasma expander (Hemospan) administered to orthopaedic surgery patients with spinal anaesthesia

The objective of this study was to further explore the safety of Hemospan (Sangart Inc., San Diego, CA, USA), an oxygen-carrying plasma expander. The aim of this study was to determine if Hemospan is well tolerated in orthopaedic surgery patients with spinal anaesthesia in doses up to 1 L. Hemospan was previously found to be well tolerated in normal volunteers and orthopaedic surgery patients with spinal anaesthesia in doses up to 500 mL. Five cohorts of six orthopaedic surgery patients, American Society of Anesthesiologists (ASA) I and II, were studied. In each cohort, four patients received Hemospan in doses ranging from 200 to 1000 mL, and two received Ringer's lactate immediately prior to induction of spinal anaesthesia. There were no serious adverse events (SAEs). Iohexol clearance measured before and 24 h after dosing was unaffected. There were 14 adverse events (AEs) in the 10 control patients (1.4 per patient) and 30 in the 20 patients receiving Hemospan (1.5 per patient). One patient in the group receiving 200 mL Hemospan had elevated mean arterial pressure after dosing, but there were no elevations in any of the other patients. The peak plasma Hemospan concentration in the 1000 mL group was 1.3 g dL(-1), with a dose-dependent clearance (T(1/2)) ranging from 14.1 to 23.0 h. Plasma methaemoglobin levels were independent of dose, reaching a maximum at 40 h after dosing and never exceeded 0.125 g dL(-1). Troponin T was transiently elevated in two patients receiving Hemospan without symptoms or electrocardiographic abnormalities or elevation of myocardial creatinine kinase isoenzyme. Hemospan was well tolerated in this group of patients at doses up to 1000 mL.

Analgesic efficacy of diclofenac in combination with morphine and paracetamol after mastectomy and immediate breast reconstruction

BACKGROUND

Breast cancer treatment with mastectomy and immediate breast reconstruction (IBR) is associated with intense pain in the primary post-operative period. The present prospective, placebo-controlled and double-blind study aimed to evaluate the analgesic efficacy of diclofenac, a non-steroid anti-inflammatory drug (NSAID), in combination with paracetamol and opioids. This was done by 64-h assessment of post-operative pain intensity, opioid consumption, blood loss, nausea and tiredness.

METHODS

Fifty women selected for mastectomy and IBR with submuscular implants with or without axillary lymph node dissection (ALND) were randomized to receive diclofenac 50 mg x 3 or placebo rectally in addition to oral paracetamol and intravenous opioids delivered using a patient-controlled analgesia (PCA) technique.

RESULTS

During the first 20 h post-surgery, patients who received diclofenac experienced significantly less pain when resting than those who received placebo. When moving, a non-significant estimated difference in pain in favour of diclofenac was also noted. Opioid consumption during the first 6 h post-operatively was 34% less with diclofenac than with placebo. Means (SD) were 16.9 (10.3) mg and 25.6 (10.2) mg, respectively (P = 0.007). After 64 h, the difference was no longer statistically significant. Post-operative bleeding was significantly higher with diclofenac than with placebo (P < 0.01). Nausea and tiredness did not differ between the groups.

CONCLUSIONS

The addition of NSAID to paracetamol and opioid-PCA reduced opioid consumption and improved pain relief during the first 20 h at rest but was not convincingly effective during mobilization. Post-operative blood loss was higher with diclofenac.

Low-dose bupivacaine with sufentanil prevents hypotension after spinal anesthesia for hip repair in elderly patients

BACKGROUND

Hip fracture is common in the geriatric population. Patients in this group are often at high risk for perioperative complications from concurrent diseases. Conventional spinal anesthesia can be associated with hypotension but has a better postoperative outcome compared to general anesthesia. We judged that a reduced dose of bupivacaine in combination with sufentanil could give reliable blocks with minimal hypotension.

METHODS

Fifty elderly patients were randomized into two groups. The study group received spinal anesthesia as a combination of hyperbaric bupivacaine 7.5 mg and sufentanil 5 microg while the control group received hyperbaric bupivacaine 15 mg. The hemodynamic stability of the patients and the quality of the blocks were compared.

RESULTS

All patients had adequate duration of reliable blocks. More control group patients than study group patients required ephedrine due to hypotension.

CONCLUSION

A reduced dose of hyperbaric bupivacaine (7.5 mg) in combination with sufentanil (5 microg) provides reliable spinal anesthesia for the repair of hip fracture in aged patients with few events of hypotension and little need for vasopressor support of blood pressure.

A preliminary evaluation of a new selective agar supplemented with desferrioxamine for detection of methicillin-resistant Staphylococcus aureus

The aim of the present study was to evaluate the performance of two new selective screening agars, Colombia agar supplemented with 1000 mg/L desferrioxamine, 5 mg/L amphotericin B, 16 mg/L polymyxin B, and 2 mg/L methicillin (CMDAP agar) or 0.5 mg/L oxacillin (CODAP agar), for detection of methicillin-resistant Staphylococcus aureus (MRSA). Both the CMDAP and the CODAP agar effectively inhibited growth of 151 isolates of coagulase-negative staphylococci (CoNS), 45 of Enterobacteriaceae and six Candida spp. examined. The sensitivity and specificity of the CMDAP and CODAP agars for detection of MRSA was calculated by comparing the growth of 52 MRSA with the inhibition of 74 mecA negative S. aureus and of 151 CoNS. The performance of the new agars was compared with four previously described MRSA screening agars. The sensitivity and specificity for detection of MRSA after incubation at 35 degrees C for 24 h was 0.94 and 0.91, respectively, for the CMDAP agar, 0.60 and 0.90 for the CODAP agar, 0.98 and 0.57 for methicillin aztreonam mannitol salt agar (MAMSA), 0.23 and 0.84 for oxacillin mannitol salt agar (OMSA), 0.48 and 0.76 for oxacillin Mueller-Hinton agar (OMHA) and 0.75 and 0.77 for lithium oxacillin mannitol salt agar (LOMSA). Agars supplemented with desferrioxamine, CMDAP and CODAP, were more specific for detecting MRSA compared with agars not supplemented with desferrioxamine. The detection rate was higher for agars supplemented with methicillin than for agars supplemented with oxacillin.

Parahydrogen-induced polarization in imaging: subsecond (13)C angiography

High nuclear spin polarization of (13)C was reached in organic molecules. Enhancements of up to 10(4), compared to thermal polarization at 1.5 T, were achieved using the parahydrogen-induced polarization technique in combination with a field cycling method. While parahydrogen has no net polarization, it has a high spin order, which is retained when hydrogen is incorporated into another molecule by a chemical reaction. By subjecting this molecule to a sudden change of the external magnetic field, the spin order is transferred into net polarization. A (13)C angiogram of an animal was generated in less than a second. Magn Reson Med 46:1-5, 2001.

Cesarean section under epidural ropivacaine 0.75% in a parturient with severe pulmonary hypertension

Pregnancy and delivery are a potentially lethal combination in a patient with primary pulmonary hypertension. There are controversies regarding mode of delivery. Cesarean section is considered to be associated with extensive perioperative risks. We report on a parturient with severe pulmonary hypertension who underwent a succesful semiemergent cesarean section on vital indication. Vaginal delivery was excluded since her cervix was too immature for succesful induction. This is the first reported case of its kind to receive an epidural anesthesia with ropivacaine with its potential advantage of a low cardiac toxicity. The epidural was slowly and carefully titrated to give a stable anesthesia with good quality.

Genotyping of the capsule gene cluster (cps) in nontypeable group B streptococci reveals two major cps allelic variants of serotypes III and VII

Forty group B Streptococcus (GBS) isolates obtained from Europe and the United States previously reported to be nontypeable (NT) by capsule serotype determination were subjected to buoyant density gradient centrifugation. From nearly half of the isolates capsule-expressing variants could be selected. For characterization of the remaining NT-GBS isolates, the capsule operon (cps) was amplified by the long-fragment PCR technique and compared by restriction fragment length polymorphism (RFLP) analysis. The patterns from serotype reference isolates (n = 32) were first determined and used as a comparison matrix for the NT-GBS isolates. Using two restriction enzymes, SduI and AvaII, cluster analysis revealed a high degree of similarity within serotypes but less than 88% similarity between serotypes. However, serotypes III and VII were each split in two distant RFLP clusters, which were designated III(1) and III(2) and VII(1) and VII(2), respectively. Among the isolates that remained NT after repeated Percoll gradient selections, two insertional mutants were revealed. Both were found in blood isolates and harbored insertion sequence (IS) elements within cpsD: one harbored IS1548, and the other harbored IS861. All other NT-GBS isolates could, by cluster analysis, be referred to different serotypes by comparison to the RFLP reference matrix. In pulsed-field gel electrophoresis of SmaI-restricted chromosomal DNA, patterns from allelic type 1 and 2 isolates were essentially distributed in separate clusters in serotypes III and VII. A covariation with insertion sequence IS1548 in the hylB gene was suggested for serotype III, since allelic type III(1) harboring IS1548 in hylB, clustered separately. The variation in serotype VII was not dependent on the presence of IS1548, which was not detected at any position in the type VII chromosome.

A comparison of three doses of sufentanil in combination with bupivacaine-adrenaline in continuous epidural analgesia during labour

BACKGROUND

Sufentanil is now frequently added to local anaesthetic in labour epidural analgesia. However, this opioid has some side effects such as pruritus, and in higher doses could harm the neonate. The purpose of this study was to compare three doses of sufentanil combined with low-dose bupivacaine, to determine the lowest appropriate dose.

METHOD

In a prospective, randomized, double-blind study, 243 parturients were randomized, to receive A--0.5 microg/ml, or B--0.75 microg/ml or C--1 microg/ml sufentanil, in addition to bupivacaine 0.625 mg/ml+adrenaline 1.25 microg/ml. All were given an 8 ml bolus of the study solution, followed by continuous infusion at 6 ml/h. The analgetic effect was scored on a visual analogue scale (VAS). Onset quality was measured as VAS after 20 min, the total effect as VAS maximum during the first stage of labour. Overall maternal satisfaction was recorded within two hours post partum. Side effects were noted.

RESULTS

There were no differences between groups in VAS assessments after 20 min or in maximum registered VAS. In group A, 83% had VAS 0-4 after 20 min, in group B 77% and in group C 71%. Maximum VAS during the first stage was 0-4 for 60% of group A, 68% of group B and 61% of group C. Maternal satisfaction was also the same in the three groups. In group A, 70% reported excellent effect and 22% good effect. The corresponding figures in group B were 68% and 24% respectively, and in group C 62% and 24% respectively. Group A received a mean total dose of 21 microg sufentanil, group B 30 microg and group C 44 microg. Pruritus occurred in 51% of group A, 53% of group B and 65% of group C.

CONCLUSION

We found no difference in the analgesic effect between three different concentrations of sufentanil. We conclude that the lowest dose may be used. This should decrease the risk of adverse effects on mother and child.

Islet amyloid polypeptide in the islets of Langerhans: friend or foe?

Islet amyloid polypeptide (IAPP), or amylin, was originally discovered as the constituent peptide in amyloid occurring in human insulinomas and in pancreatic islets in human subjects with Type II (non-insulin-dependent) diabetes mellitus. Its normal expression in beta cells and its co-secretion with insulin in response to nutrient stimuli, suggest a metabolic function for the peptide. Specifically, IAPP has most frequently been shown to inhibit insulin secretion, implying that IAPP has a role in the regulation of islet hormone homeostasis. The physiological significance of IAPP in islets has been difficult to assess; very high IAPP concentrations are required to alter insulin secretion. Moreover, until recently, IAPP receptors have not been characterised at the molecular level, thus leaving the actual target cells for IAPP unidentified. Furthermore, in experimental diabetes in rodents, the ratio of IAPP expression to that of insulin invariably is increased. In view of the pleiotropic effects attributed to IAPP, such regulation could be both adverse and beneficial in diabetes. Metabolic characterisation of mice carrying a null mutation in the IAPP gene or which overexpress IAPP in beta cells have recently confirmed that IAPP is a physiological inhibitor of insulin secretion. Based on experiments in which IAPP-deficient mice develop a more severe form of alloxan-induced diabetes, we argue that the action of IAPP in the islets normally is beneficial for beta-cell function and survival; thus, the established up regulation of IAPP expression compared with that of insulin in experimental rodent diabetes could serve to protect islets under metabolically challenging circumstances.

Clonal spread of staphylococci among patients with peritonitis associated with continuous ambulatory peritoneal dialysis

BACKGROUND

Peritonitis is the most important complication of continuous ambulatory peritoneal dialysis (CAPD). Coagulase-negative staphylococci (CNS) are the most common causes of peritonitis, only limited information is available regarding the distribution and epidemiology of different CNS species associated with CAPD peritonitis.

METHODS

CNS isolated from dialysis effluent from CAPD patients with peritonitis was identified by species and further analyzed with pulsed-field gel electrophoresis (PFGE).

RESULTS

A total of 216 microorganisms (206 bacteria and 10 Candida species) were isolated from 196 consecutive culture-positive CAPD samples obtained from 75 patients. One hundred and twenty-one (56%) isolates represented staphylococci. The four most frequently isolated staphylococcal species were Staphylococcus epidermidis (70 isolates), Staphylococcus aureus (31 isolates), Staphylococcus hemolyticus (10 isolates), and Staphylococcus hominis (4 isolates). PFGE analysis revealed the clonal spread among patients of three different clones of S. epidermidis and one clone of S. aureus among the investigated patients. Indistinguishable isolates of either S. epidermidis, S. hominis, or S. aureus were also isolated in repeated samples from several patients.

CONCLUSION

PFGE is a useful method for the epidemiological evaluation of staphylococci-associated CAPD infections and should replace older and less accurate methods, such as antibiotic sensitivity patterns. We recommend that CNS isolates from patients with CAPD-associated peritonitis should be saved for future investigations and typing, which would aid in the management of this patient category.

Antibiotic susceptibility of staphylococci isolated in blood cultures in relation to antibiotic consumption in hospital wards

A total of 510 isolates of Micrococcaceae, 500 of staphylococci and 10 micrococci, detected in 485 (3.3%) of 14,860 consecutive blood cultures obtained from patients at a Swedish university hospital and 2 local hospitals were identified to species level and investigated for antibiotic susceptibility. The 5 most frequently isolated species were Staphylococcus epidermidis (54.8%), S. aureus (28.0%), S. hominis (3.4%), S. warneri (3.2%) and S. haemolyticus (2.8%). All isolates of S. aureus were oxacillin sensitive. Great diversity in antibiotic resistance among coagulase negative staphylococci between hospitals and different ward units in the university hospital was observed. The frequency of antimicrobial resistance among S. epidermidis correlated with the antibiotic consumption at different ward units, in particular for ciprofloxacin (p < 0.001) and co-trimoxazole (p < 0.004). The study emphasizes the importance of monitoring antibiotic consumption and resistance patterns of nosocomial staphylococci in order to avoid emergence and spread of multi-resistant bacteria within the hospital environment.

Postantibiotic effect and postantibiotic sub-mic effect of dirithromycin and erythromycin against respiratory tract pathogenic bacteria

The postantibiotic effect (PAE) of dirithromycin and erythromycin against strains Streptococcus pyogenes group A M12, NCTC P1800, Streptococcus pneumoniae 23, Staphylococcus aureus Oxford strain 209, Moraxella catarrhalis 15616 and Haemophilus influenzae 5590 was investigated in vitro and in vivo by use of the tissue cage model in rabbits. By exposing strains to 2.5-5 x MIC levels for 6 h or 12 h, both compounds induced in vitro PAEs of 1-9 h, and in two cases >20 h. Cultures in the PAE-phase were then re-exposed to subinhibitory concentrations (0.25 x MIC and 0.5 x MIC) of antibiotic and prolonged suppression of regrowth was obtained for 2->20 h. Following i.v. antibiotic treatment of rabbits (10 mg/kg or 20 mg/kg dirithromycin and 20 mg/kg or 40 mg/kg erythromycin) and bacterial infection of the implanted tissue cages in the same rabbit, the tissue cage fluid (TCF) was sampled 6 h after infection and regrowth was monitored by sampling from new tissue cages in untreated rabbits. These i.v. single doses of both antibiotics induced in vivo PAEs of >6 h, but <20 h against S. pyogenes. Suppression of regrowth in TCF was also obtained for > or = 20 h on infection with exposed S. pyogenes in the PAE-phase in newly implanted tissue cages in rabbits that had been treated with low doses of antibiotic to produce subinhibitory concentrations in the TCE Dirithromycin was in general as active as erythromycin in inducing PAE and in prolonging suppression of bacterial regrowth in the PAE phase.

Drugs up in smoke: a study of caseated drugs in Sweden

DESIGN

Cross-sectional survey.

SETTING

The county of Malmöhus, with 817,000 inhabitants, in the far south of Sweden. All drugs handed in for destruction to the 65 pharmacies during one week in March 1996 were analysed.

RESULTS

92% of the packages were prescription drugs for human use, 7% were over-the-counter drugs, and 1% were for veterinary use. Slightly less than half (48%) had expired when they were handed in for destruction. 36% were unbroken when returned and another 18% of the packages were nearly full. A comparison between the drugs sent in for destruction and the drugs sold in the county gave a ratio of 0.030. Antineoplastic and immunosuppressive drugs, drugs for the respiratory system, antiparasitic products, and cardiovascular drugs were returned to a greater extent than other types of drugs. Drugs for the genito-urinary tract, sex hormones, and drugs for the alimentary tract were returned to a lesser extent. Extrapolated to a whole year the value of caseated drugs was estimated to 60 SEK (5.83 Br,) per person. The value of unbroken packages was 20 SEK (1.94 Br,) per person per year.

CONCLUSION

Although not all of the drugs handed in for destruction could have been unnecessarily prescribed or obtained by the patient, a more cautious approach to prescribing of drugs would likely yield significant savings.

In vitro inhibition of S. pneumoniae, nontypable H. influenzae and M. catharralis by alpha-hemolytic streptococci from healthy children

The present study aimed to investigate the inhibitory activity of the normal epipharyngeal flora against the three most common acute otitis media (AOM) pathogens in healthy children, and to study if the inhibitory activity differs between alpha-hemolytic streptococci (AHS) sampled from the tubal orifice and from those sampled from the adenoid. A total number of ten isolates of AHS were collected from the tubal orifice and the adenoid, respectively, in ten children undergoing adenoidectomy or tonsillectomy. None of the children had a history of otitis media, neither secretory otitis media (SOM) nor AOM. The method used to test the bacterial interference in vitro was a modified agar overlay method. The results showed that the AHS from nasopharynx were able to inhibit the majority of the S. pneumoniae, nontypable Haemophilus influenzae and Moraxella catharralis isolates tested. The AHS isolates from the tubal orifice inhibited growth of 93% of S. pneumoniae, 79% of H. influenzae and 84% of M. catharralis isolates. The corresponding figures among isolates from the adenoid were 76, 48 and 62%. This difference in the inhibitory capacity between the AHS isolates collected from the adenoid, compared with the AHS collected from the tubal orifice, is statistically significant (P<0.01) and implies that it is important to know the exact sampling locality before conclusions are made concerning the significance of bacterial interference in the upper airways.

Traditional analgesic agents: are parenteral narcotics passé and do inhalational agents still have a place in labour?

Systemic labour pain treatment with opioids and inhaled nitrous oxide has for many decades frequently been used in medically developed countries. Self-administered nitrous oxide (50% in oxygen) has never gained the same popularity in the USA as in the UK or Scandinavia but the use of opioids, mainly pethidine, has generally been widespread in spite of well-known negative effects on the postnatal adaptation of the newborn. Since the often very intense labour pain seems to respond very poorly even to highly sedating doses of parenteral opioids, their frequent use during delivery and parturition has to be questioned. Self-administered inhalation of nitrous oxide 50% in oxygen also has a limited efficacy for relieving labour pain but because it is mainly devoid of adverse effects on the baby or on the parturient its future use in obstetrics can be defended more easily, either as a sole agent in women with low labour pain scores or in early labour preceding epidural analgesia.

Pharmacokinetics and clinical effect during continuous epidural infusion with ropivacaine 2.5 mg/ml or bupivacaine 2.5 mg/ml for labour pain relief

BACKGROUND

Ropivacaine has shown less systemic toxicity than bupivacaine, and comparatively low muscle-blocking properties could constitute another advantage when used epidurally for obstetric pain relief. We aimed primarily to compare maternal and foetal drug disposition following continuous epidural infusion of ropivacaine or bupivacaine.

METHODS

Twenty-four full-term, nulliparous women were randomized to continuous epidural infusion (10 ml/h) of ropivacaine 2.5 mg/ml or bupivacaine 2.5 mg/ml for labour pain relief in a double-blind, parallel-group design. Maternal blood samples were collected up to 24 h after the end of infusion as well as taken from the umbilical cord at the time of delivery. Sensory and motor block as well as analgesia were assessed. All the women were monitored by cardiotocography and neonatal assessment was performed.

RESULTS

The sensory block was adequate for both drugs. Higher plasma levels (total and free) were seen with ropivacaine, although the infusion with bupivacaine continued on average for about 2 hours longer. However, the ratios between maternal and umbilical blood concentrations were similar for both drugs. Normal neonatal Apgar and neonatal adaptive capacity scores (NACS) were found in both groups.

CONCLUSION

A continuous epidural infusion of 25 mg/h ropivacaine or bupivacaine both produced good labour pain relief. Higher total and free plasma concentrations were seen for ropivacaine. The ratios between maternal and umbilical plasma levels were similar for both drugs.

An inexpensive and reliable method for routine identification of staphylococcal species

The aim of this study was to develop a simple, reliable, and inexpensive in-house system for routine species identification of staphylococci in clinical practice. The system combines 15 key tests (including carbohydrate fermentation) performed in micro-well strips and antimicrobial disk diffusion susceptibility tests performed on standardised paper disk method antibiotic sensitivity medium agar. Twenty-eight staphylococcal reference strains belonging to 18 different species were correctly identified using this in-house system. A total of 291 clinical staphylococci isolates were evaluated with the in-house system and a conventional identification scheme. The in-house system identified 281 (96.6%) of these 291 isolates. Eleven different species were recognised. The five species most frequently identified were Staphylococcus epidermidis (48.6%), Staphylococcus aureus (27.8%), Staphylococcus haemolyticus (8.2%), Staphylococcus hominis (5.7%), and Staphylococcus warneri (5.3%). There was an agreement of 86.3% between the species identification obtained with the in-house system and the conventional identification scheme. All coagulase-negative isolates initially identified as species other than Staphylococcus epidermidis as well as indistinctly identified isolates were also evaluated with a commercial identification system. The agreement between species identification obtained with the in-house system and the commercial system for 101 identified isolates was 73%. Several isolates that were difficult to distinguish with the conventional scheme and/or the commercial system were identified with the aid of the antimicrobial susceptibility test included in the in-house system. The described test scheme should be of value for identification of clinically significant staphylococci species.

Obstetric outcome following epidural analgesia with bupivacaine-adrenaline 0.25% or bupivacaine 0.125% with sufentanil--a prospective randomized controlled study in 1000 parturients

BACKGROUND

Epidural analgesia (EDA) is the most efficient method for pain relief during labour, but there is still a debate as to whether it interferes with the normal process of delivery. Some authors argue that the incidence of instrumental deliveries, Caesarean section, malrotation and protracted labour is increased in parturients receiving EDA.

METHODS

1000 parturients were prospectively randomized to receive EDA either with a high dose of local anaesthetic (0.25% bupivacaine with adrenaline = HD) or with a low dose (0.125% bupivacaine with sufentanil 10 micrograms = LD).

RESULTS

The incidence of instrumental delivery and Caesarean section and the need for oxytocin was reduced in the LD compared to HD group. The delivery time was similar with HD and LD among primiparous, but decreased significantly among multiparous in the LD group. The incidence of malrotation was low in both groups. The quality of analgesia was equal during the first stage in the 2 groups, but was lower in the LD group during the second stage. More parturients in the LD group ambulated, but this did not affect the incidence of instrumental delivery.

CONCLUSION

It is concluded that a lower dosage of bupivacaine combined with sufentanil in epidural analgesia significantly improves the obstetric outcome as compared to a higher dosage of bupivacaine with adrenaline using intermittent bolus technique.

Ropivacaine 7.5 mg/ml for elective caesarean section. A clinical and pharmacokinetic comparison of 150 mg and 187.5 mg

BACKGROUND

The new, long-acting local anaesthetic ropivacaine has shown less systemic toxicity than bupivacaine and a concentration of 7.5 mg/ml can therefore be used for epidural anaesthesia in Caesarean section. The present pilot study was undertaken to find indications for an optimal dosage by comparing the clinical effects, quality of anaesthesia and pharmacokinetics of ropivacaine 150 mg (lower dose = LD) vs 187.5 mg (higher dose = HD) for women undergoing elective Caesarean section under epidural anaesthesia.

METHODS

Sixteen full-term women scheduled for elective Caesarean section in two equal-sized consecutive groups received 20 or 25 ml ropivacaine epidurally in this non-randomised, open study. Study parameters included sensory and motor blockade, circulatory response, intraoperative pain and discomfort, neonatal evaluation and pharmacokinetic determinations.

RESULTS

Block height varied between T5 and T2 in the LD group, whereas the HD group produced 4 unnecessarily high blocks (C8 in 3 women and C7 in 1 woman). Surgical anaesthesia was excellent in both groups. Circulatory stability was pronounced in the LD group (no ephedrine given), while 4 women required ephedrine in the HD group. Neonatal outcome as judged by Apgar scores; umbilical blood gas determinations and NACS scores were excellent in both groups. The plasma concentration-time profiles indicated linearity in the concentration range studied, with similar clearance values to those reported previously. Placental drug equilibrium was rapid; however, the foetal drug exposure depended on intrauterine exposure time.

CONCLUSIONS

20-25 ml ropivacaine 7.5 mg/ml produced very satisfactory conditions for elective Caesarean section under epidural anaesthesia. In this small population, 150 mg ropivacaine seemed optimal, while 187.5 mg produced unnecessarily extended block height in 50% of the women.

Increased cerebrospinal fluid concentration of aspartate but decreased concentration of nitric oxide breakdown products in women experiencing visceral pain during active labour

The aim of the present study was to investigate some putative neurotransmitters involved in nociception and pain in parturients during active labour experiencing intense visceral pain. The concentration of the excitatory amino acid aspartate was significantly increased, and there was a tendency for an increase in glutamate, in lumbar cerebrospinal fluid (CSF) of parturients in active vaginal labour compared with control patients without pain subjected to elective caesarean section. The CSF concentration of the nitric oxide breakdown product nitrate was significantly decreased in parturients compared with control patients and healthy volunteers. No significant differences in the concentrations of substance P, substance P-endopeptidase or met-enkephalin were detected between parturients and controls. Our data suggest a paradoxical negative relationship between CSF concentrations of excitatory amino acids and nitric oxide in labour pain. The mechanisms behind this finding is unclear at present.

Anesthetic quality during cesarean section following subarachnoid or epidural administration of bupivacaine with or without fentanyl

BACKGROUND

It is often assumed that subarachnoid administration of local anesthetics produces a more profound blockade than epidural anesthesia. Furthermore, the addition of fentanyl has been reported to increase preferentially intraoperative analgesia. In the present study we set out to study these two issues in a randomized and controlled study with respect to perceived pain and discomfort during surgery and postoperative pain.

METHODS

In the present study, 100 parturients subjected to elective cesarean section, 34 nullipara and 66 multipara, received one out of four combinations of the local anesthetic bupivacaine and the opioid fentanyl; group A--bupivacaine 12.5 mg + 10 micrograms fentanyl subarachnoidally, group B--bupivacaine 12.5 mg + saline subarachnoidally, group C--bupivacaine 100 mg + 100 micrograms fentanyl epidurally, group D--bupivacaine 100 mg + saline epidurally; N = 25 in each group. Pain intensity and discomfort during surgery was assessed with a visual analogue scale (VAS). Postoperative pain intensity and need for analgesics postoperatively, ketobemidone, was registered for 24 h following surgery.

RESULTS

Intraoperative pain intensity and discomfort did not differ significantly between parturients in any of the four groups Postoperative pain was significantly more intense in parturients receiving local anesthetics subarachnoidally as compared to the epidural groups during the first 6-h period. This difference was also reflected in a significantly increased consumption of analgesics during this period. No significant differences between the groups were observed with regard to hemodynamics (blood pressure), respiration (oxygen saturation) or other effects such as nausea or itching. All neonates had normal Apgar and neonatal adaptive capacity scores (NACS).

CONCLUSION

We conclude that subarachnoidal (12.5 mg) and epidural (100 mg) injections with bupivacaine both produced adequate anesthetic quality in women undergoing elective cesarean section. The addition of fentanyl (10 micrograms subarachnoidally or 100 micrograms epidurally) did not significantly improve the quality of these already profound blockades.

Lack of analgesic effect of systemically administered morphine or pethidine on labour pain

OBJECTIVE

To evaluate the true analgesic effect of morphine and pethidine on labour pain.

DESIGN

The analgesic and sedative effects of intravenous morphine or pethidine and their effect on anxiety were compared in a prospective, double-blind, randomised dose-response study.

SETTING

A Stockholm teaching hospital obstetric unit.

PARTICIPANTS

Ten healthy nulliparous parturients in active labour were included in each group.

RESULTS

Even after repeated doses (up to 0.15 mg/kg body weight morphine and up to 1.5 mg/kg body weight pethidine) the findings were uniform, with very high pain scores maintained in each group as assessed with visual analogue scale. The parturients were all significantly sedated and several fell asleep but were awakened by pain during contractions.

CONCLUSION

It is concluded that labour pain is not sensitive to systemically administered morphine or pethidine. These drugs only cause heavy sedation. It therefore seems unethical and medically incorrect to meet parturients' requests for pain relief by giving them sedation. Considering the well documented negative effects on newborn infants we also believe systemic pethidine should be avoided in labour.

Analgesic efficacy of intravenous morphine in labour pain: a reappraisal

The aim of the present study was to investigate the dose-related analgesic effect of intravenous (i.v.) morphine during spontaneous term first stage labour. This was an open study in 17 parturients who requested analgesia for severe labour pain. All women were given morphine i.v. in repeated doses of 0.05 mg/kg following every third contraction until a final dose of 0.20 mg/kg was reached. The decrease in overall pain intensity, from median visual analogue scale (VAS) 85 (range 52-100) to median VAS 70 (range 46-99), was clinically insignificant. The number of women experiencing back pain, however, decreased significantly following morphine. The most striking effect of morphine (7.2-18 mg) was pronounced sedation. No adverse reactions related to morphine were noted in the neonates. We conclude that i.v. morphine does not significantly reduce overall labour pain intensity. Thus, if a real analgesic effect is desired, systemically given morphine seems inappropriate and other techniques should be used.

Peripartum cardiomyopathy--three cases

Three cases of peripartum cardiomyopathy (PPCM) are presented, each illustrating a clinically important aspect of the disorder. One patient survived despite extreme haemodynamic deterioration, one died suddenly 2 months post partum although clinically recovered, and one died during a subsequent pregnancy. The cases demonstrate the severity and the unpredictable course of PPCM, which remains a challenge both to scientists and to clinicians.