Are premature ventricular contractions always harmless?

INTRODUCTION: Premature ventricular contractions (PVCs) are among the most prevalent arrhythmias. PVCs lead to haemodynamically insufficient heartbeats. Their presence is considered rather insignificant, but this widespread assumption is not supported by research evidence. CASES: We present three cases of patients commonly seen in daily general practice, with a range of presentations, varying from incidental (harmless) PVCs to frequent and potentially symptomatic PVCs. DISCUSSION: In more frequent PVCs (> 10% heart beats) fatigue and exertional dyspnoea may occur. When > 20% of heart beats are PVCs, patients may develop cardiomyopathy and heart failure. Incidental PVCs are harmless. Anti-arrhythmic drug treatment should be considered in case of frequent PVCs but also catheter ablation appears an effective treatment option. CONCLUSION: Altogether, PVCs may not be harmless, depending on their occurrence rate. Research data from primary care settings on epidemiology and natural course is needed.

Perinatal mortality and morbidity in a nationwide cohort of 529,688 low-risk planned home and hospital births.

OBJECTIVE: To compare perinatal mortality and severe perinatal morbidity between planned home and planned hospital births, among low-risk women who started their labour in primary care. DESIGN: A nationwide cohort study. SETTING: The entire Netherlands. POPULATION: A total of 529,688 low-risk women who were in primary midwife-led care at the onset of labour. Of these, 321,307 (60.7%) intended to give birth at home, 163,261 (30.8%) planned to give birth in hospital and for 45,120 (8.5%), the intended place of birth was unknown. METHODS: Analysis of national perinatal and neonatal registration data, over a period of 7 years. Logistic regression analysis was used to control for differences in baseline characteristics. MAIN OUTCOME MEASURES: Intrapartum death, intrapartum and neonatal death within 24 hours after birth, intrapartum and neonatal death within 7 days and neonatal admission to an intensive care unit. RESULTS: No significant differences were found between planned home and planned hospital birth (adjusted relative risks and 95% confidence intervals: intrapartum death 0.97 (0.69 to 1.37), intrapartum death and neonatal death during the first 24 hours 1.02 (0.77 to 1.36), intrapartum death and neonatal death up to 7 days 1.00 (0.78 to 1.27), admission to neonatal intensive care unit 1.00 (0.86 to 1.16). CONCLUSIONS: This study shows that planning a home birth does not increase the risks of perinatal mortality and severe perinatal morbidity among low-risk women, provided the maternity care system facilitates this choice through the availability of well-trained midwives and through a good transportation and referral system.

A trend analysis in referrals during pregnancy and labour in Dutch midwifery care 1988-2004.

OBJECTIVE: To assess the trends and patterns of referral from midwives to obstetricians within the Dutch maternity care system from 1988 to 2004, and the differences in referral patterns between nulliparous and parous women. DESIGN: A descriptive study. SETTING: The Dutch midwifery database (LVR1), which monitored 74% (1988) to 94% (2004) of all midwifery care in the Netherlands between 1988 and 2004. POPULATION: A total of 1 977 006 pregnancies, attended by a primary care level midwife. METHODS: The indications for referral from midwifery to obstetric care were classified into fifteen groups (eight antepartum, six intrapartum and one postpartum). The trends in referrals of these indications were analysed by general linear models. MAIN OUTCOME MEASURES: Trends in the percentage of antepartum, intrapartum and postpartum referrals from midwifery care to obstetric care; trends in the specific indications for referral; contribution of different groups of the indications to the trend. RESULTS: From 1988 to 2004 an increase of 14.5% (from 36.9 to 51.4%) occurred in referrals from primary midwifery care to secondary obstetric care either during pregnancy, childbirth or in the postpartum period. The timing of the referrals was as follows: antepartum +9.0%, intrapartum +5.2% and postpartum +0.3%. In parous women, the increase in referrals was greater (+16.6%) than in nulliparous women (+12.3%) (P = 0.001). The commonest indications for referrals in nulliparous women were anticipated or evident complications due to 'failure to progress in the first or second stage' and 'fetal distress'. Parous women were most commonly referred for anticipated or evident complications due to 'medical history' and 'fetal distress'. In nulliparous women, 52% of the increase in referrals was related to the need of pain relief and occurrence of meconium-stained amniotic fluid; in parous women, 54% of the increase in referrals was related to the general medical and obstetrical history of the women, particularly previous caesarean section, and the occurrence of meconium-stained amniotic fluid. CONCLUSIONS: During a 17-year period, there was a continuous increase in the referral rate from midwives to obstetricians. Previous caesarean section, requirement for pain relief and the presence of meconium-stained amniotic fluid were the main contributors to the changes in referral rates. Primary prevention of caesarean section and antenatal preparation for childbirth are important interventions in the maintenance of primary obstetric care for low-risk pregnant women.

[Ethnic differences in preference for home delivery and in pregnancy care received by pregnant women]. / Etnische verschillen in de voorkeur voor thuisbevallingen en het zorgtraject dat zwangeren doorlopen.

OBJECTIVE: To investigate differences among pregnant women from various ethnic groups in terms of pregnancy care and the place of delivery. DESIGN: Descriptive, retrospective study. METHOD: Data from the Dutch Perinatal Registries during the period 1995-2002, representing a total of 1,401,892 pregnancies, were linked and analysed for perinatal care, the place of the delivery and the ethnic group of the mother. The ethnic categories defined in the registries were: Dutch, Mediterranean, other European, African, Hindu, Asian and unknown. RESULTS: Other European women and Asian women often started pregnancy care with a midwife and were not often referred to secondary care with an obstetrician. These two groups most often completed the delivery under the care of a midwife (45.3% of other European women and 44.6% of Asian women). As Hindu and African women often started pregnancy care directly with an obstetrician due to medical reasons and were often referred to secondary care during pregnancy or birth, these two groups were least likely to complete their births under the primary care of a midwife (33.1% and 28.0%, respectively). 39% of the Dutch women completed delivery with a midwife. Of those women who started the delivery under the care of a midwife, 3 out of 4 Dutch women, 1 out of 3 Mediterranean women and only 1 out of 5 Hindu women ultimately elected for a home birth. CONCLUSION: Large ethnic differences exist in both pregnancy care and preference for place of delivery and, ultimately, place of birth. This should be taken into account in policy-making and in the provision of information regarding the Dutch midwifery system.

Evaluation of 280,000 cases in Dutch midwifery practices: a descriptive study.

OBJECTIVE: To assess the nature and outcome of intrapartum referrals from primary to secondary care within the Dutch obstetric system. DESIGN: Descriptive study. SETTING: Dutch midwifery database (LVR1), covering 95% of all midwifery care and 80% of all Dutch pregnancies (2001-03). POPULATION: Low-risk women (280,097) under exclusive care of a primary level midwife at the start of labour either with intention to deliver at home or with a personal preference to deliver in hospital under care of a primary level midwife. METHODS: Women were classified into three categories (no referral, urgent referral and referral without urgency) and were related to maternal characteristics and to neonatal outcomes. MAIN OUTCOME MEASURES: Distribution of referral categories, main reasons for urgent referral, Apgar score at 5 minutes, perinatal death within 24 hours and referral to a paediatrician within 24 hours. RESULTS: In our study, 68.1% of the women completed childbirth under exclusive care of a midwife, 3.6% were referred on an urgency basis and 28.3% were referred without urgency. Of all referrals, 11.2% were on an urgency basis. The main reasons for urgent referrals were fetal distress and postpartum haemorrhage. The nonurgent referrals predominantly took place during the first stage of labour (73.6% of all referrals). Women who had planned a home delivery were referred less frequently than women who had planned a hospital delivery: 29.3 and 37.2%, respectively (P < 0.001). On average, the mean Apgar score at 5 minutes was high (9.72%) and the peripartum neonatal mortality was low (0.05%) in the total study group. No maternal deaths occurred. Adverse neonatal outcomes occurred most frequently in the urgent referral group, followed by the group of referrals without urgency and the nonreferred group. CONCLUSIONS: Risk selection is a crucial element of the Dutch obstetric system and continues into the postpartum period. The system results in a relatively small percentage of intrapartum urgent referrals and in overall satisfactory neonatal outcomes in deliveries led by primary level midwives.

Cost-effectiveness of different treatment strategies with intrapartum antibiotic prophylaxis to prevent early-onset group B streptococcal disease.

OBJECTIVE: To estimate the costs and effects of different treatment strategies with intrapartum antibiotic prophylaxis to prevent early-onset group B streptococcal (GBS) disease in the Netherlands. The treatment strategies include a risk-based strategy, a screening-based strategy, a combined screening/risk-based strategy and the current Dutch guideline. DESIGN: Cost-effectiveness analysis based on decision model. SETTING: Obstetric care system in the Netherlands. POPULATION/SAMPLE: Hypothetical cohort of 200,000 neonates. METHODS: A decision analysis model was used to compare the costs and effects of different treatment strategies with no treatment. Baseline estimates were derived from literature and a survey among parents of children affected by GBS disease. The analysis was performed from a societal perspective, and costs and effects were discounted at a percentage of 3%. Main outcome measures Cost per quality adjusted of life-year (QALY). RESULT: The risk-based strategy will prevent 352 cases of early-onset GBS for 5.0 million Euros, indicating a cost-effectiveness ratio of 7600 Euros per QALY gained. The combined screening risk-based strategy has comparable results. The current Dutch guideline resulted in lower effects for higher costs. The screening-based strategy shows the highest reduction in cases of early-onset GBS, however, at a cost-effectiveness ratio of 59,300 Euros per QALY gained. Introducing the polymerase chain reaction (PCR) test may lead to a more favourable cost-effectiveness ratio. CONCLUSION: In the Dutch system, the combined screening/risk-based strategy and the risk-based strategy have reasonable cost-effectiveness ratios. If it becomes feasible to add the PCR test, the cost-effectiveness of the combined screening/risk-based strategy may even be more favourable.

[Evaluation and validation of a perinatal death audit by means of feedback to the caregivers]. / Evaluatie en validatie van perinatale-sterfte-audit door terugkoppeling naar zorgverleners.

OBJECTIVE: To evaluate a perinatal audit procedure by communicating the results to the caregivers (midwives and obstetricians) involved, in order to determine whether the audit led to specific suggestions for improving practice and whether evaluation of the panel assessments by caregivers leads to a different evaluation of the audit process. DESIGN: Descriptive evaluation study. METHOD: Because of privacy regulations, the results of a recently published audit concerning perinatal mortality were reported at an aggregated level. At their own request, two participating hospitals received panel assessment reports of their own cases. The audit procedure, the 77 panel assessments and the care provided were then evaluated during closed meetings with the caregivers affiliated to the respective hospitals. RESULTS: In two audited cases of mortality the caregivers judged the panel's assessments as being too light and as too severe in one other case (Cohen's kappa: 0.98). Detailed case description was considered essential to the audit procedure. While aggregated reporting of audit results provides a general understanding of substandard factors in the care provided, feedback of results on an individual practice level led to specific suggestions for improvement (in relation to medical aspects, patient-caregiver relationship and collaboration between caregivers). Lack of anonymity appeared not to be an issue for the caregivers. CONCLUSION: The feedback of perinatal audit results to the caregivers involved as well as discussion of these results led to specific starting points in the areas of collaboration, documentation and policymaking at both individual and institutional level.

Suboptimal care and perinatal mortality in ten European regions: methodology and evaluation of an international audit.

BACKGROUND: A European concerted action (the EuroNatal study) investigated differences in perinatal mortality between countries of Europe. This report describes the methods used in the EuroNatal international audit and discusses the validity of the results. METHODS: Perinatal deaths between 1993 and 1998 in regions of ten European countries were identified. The categories of death chosen for the study were singleton fetal deaths at 28 or more weeks of gestational age, all intrapartum deaths at 28 or more weeks of gestational age and neonatal deaths at 34 or more weeks of gestational age. Deaths with major congenital anomalies were excluded. An international audit panel used explicit criteria to review all cases, which were blinded for region. Subjective interpretation was used in cases of events or interventions where explicit criteria did not exist. Suboptimal factors were identified in the antenatal, intrapartum and neonatal periods, and classified as 'maternal/social', due to 'infrastructure/service organization', or due to 'professional care delivery'. The contribution of each suboptimal factor to the fatal outcome was listed and consensus was reached on a final grade using a procedure that included correspondence and plenary meetings. RESULTS: In all regions combined, 90% of all known or estimated cases in the selected categories were included in the audit. In total, 1619 cases of perinatal death were audited. Consensus was reached in 1543 (95%) cases. In 75% of all cases, the grade was based on explicit criteria. In the remaining cases, consensus was reached within subpanels without reference to predefined criteria. There was reasonable to good agreement between and within subpanels, and within panel members. CONCLUSIONS: The international audit procedure proved feasible and led to consistent results. The results that relate to suboptimal care will need to be studied in depth in order to reach conclusions about their implications for assessing the quality of perinatal care in the individual regions.

Randomised clinical trial on the effect of the Dutch obstetric peer review system.

The project "Obstetric Peer Review Interventions" (Verloskundige Onderlinge Kwaliteitsspiegeling Interventies, VOKSINT) was set-up in The Netherlands in 1994. It provided annual comparison data (quality ranking, league tables) for secondary care obstetric departments adjusted for population differences, based on the data registered in the Perinatal Database of The Netherlands (Landelijke Verloskunde Registratie, LVR). The aim of the so-called VOKS reports was to influence obstetricians' interventions in such a way that they led to a more homogeneous policy. To assess this influence, a trial was set-up, with departments randomly assigned to be or not to be informed about the VOKS results. Obstetric intervention rates and the morbidity of newborns including neonatal neurological examinations (NNEs) were assessed. Obstetric intervention rates were similar in the report group and the control group. Practice in the report group became more homogeneous (adjusted for population differences) than in the control departments, but this was only statistically significant for term caesarean section.

[Perinatal mortality assessed: results of a regional audit]. / Perinatale sterfte getoetst: resultaten van een regionale audit.

OBJECTIVE: To assess the level of suboptimal care prior to cases of perinatal death and the extent to which perinatal mortality can be reduced by further improvements in care. DESIGN: Retrospective panel audit investigation. METHOD: Cases of perinatal death occurring in 1996 and 1997 among women living in the region Zuid-Holland-Noord, the Netherlands, were identified by approaching midwives, obstetricians/gynaecologists and paediatricians/neonatologists. The medical records of the cases were studied by an expert panel using a checklist of evidence-based criteria for standard care in order to determine circumstances and actions that did not comply with professional protocols, or that indicated either low compliance of the mother or an inadequate healthcare infrastructure (so-called sub-standard factors). The panel also assessed whether the perinatal death could have been prevented. RESULTS: A total of 342 perinatal deaths were found. For 332 cases sufficient information was available for a panel assessment and for 318 cases the panel reached a consensus on the assessment. One or more sub-standard care factors were identified in more than half of the cases. In 19% of the cases the panel agreed that the sub-standard factor had 'possibly' contributed to the death, and in 6% they agreed that the sub-standard factor had 'probably' contributed to the death. In the last group the main problems involved were antenatal care (particularly a failure to detect or inadequate management of intrauterine growth retardation) and intrapartum care (too much of a 'wait and see' approach). CONCLUSIONS: This regional audit revealed that further quality improvement of obstetric care is possible if clinical practice guidelines for effective and safe care are better implemented. It is expected that these improvements could reduce the perinatal mortality rate by between 6% and 25%.

An European concerted action investigating the validity of perinatal mortality as an outcome indicator for the quality of antenatal and perinatal care.

In this paper the concepts, objectives, design, and data analysis procedures of the EuroNatal study are described. This study started in 1996 and is a concerted action including 14 countries in Europe. The EuroNatal study aims at determining the validity of national perinatal mortality rates as an outcome indicator for the quality of antenatal and perinatal care. It is based on a conceptual model describing the relationships between differences in quality of antenatal and perinatal care, maternal and infant risk factors, variation in applied definitions, reliability of registration procedures and practices, and the outcome in terms of "true" and "observed" differences in perinatal mortality. In the first part of the study data is collected at national and aggregate level; in the second part data is collected retrospectively on individual cases of perinatal mortality in a regional sample area. Analysis of the individual cases of perinatal mortality will be by means of a perinatal audit conducted by an international expert panel. The project builds upon the work done by the participants in their respective countries. By applying common research protocols, international comparability of data collection will be enhanced and will help to create a common body of knowledge in the area of perinatal epidemiology and perinatal care. Comparison between countries is likely to lead to new insights into the strengths and weaknesses of antenatal and perinatal care systems of individual countries.

Comparison of rectal to intramuscular administration of midazolam and atropine for premedication of children.

The effectiveness of midazolam and atropine as anaesthetic premedication was investigated, comparing rectal to intramuscular administration. A total of 202 children varying in age from 10 months to 9 years, who had been admitted to the Day Surgery Department for short ENT procedures, were assigned to one of two groups on a random basis. The first group (n = 102) was given 0.5 mg/kg midazolam and 0.05 mg/kg atropine as a rectal solution 30 to 75 min prior to induction, while the second group (n = 100) was given 0.15 mg/kg midazolam and 0.02 mg/kg atropine as an intramuscular injection 20 to 60 min prior to induction. The levels of sedation and salivation were compared, as was the degree of tolerance to intravenous induction. The parents of children older than 3 years of age were given a questionnaire designed to determine the degree of amnesia. We found this combination of drugs to be effective in the relief of anxiety, the inhibition of salivary secretion and the promotion of memory loss, regardless of the route of administration. We feel that rectal administration is preferable because it is not associated with pain or anxiety.

Comparison of metabolites in skeletal muscle biopsies from normal humans and those susceptible to malignant hyperthermia.

In earlier work on malignant hyperthermia (MH) susceptible pigs the concentration of muscle metabolites differed from that found in normal control pigs. Therefore, in the present study these metabolites were measured in human muscle biopsies to find out whether normal individuals could be discriminated from MH-susceptible persons. Analysis of skeletal muscle metabolites was performed on skeletal muscle obtained from humans (n = 68) being screened to exclude or confirm susceptibility to MH. Three groups were identified based on the reaction pattern of a skeletal muscle sample exposed in vitro to caffeine or halothane 1% plus caffeine: 1) MH susceptible (MHS; n = 19); 2) normal humans, (controls; n = 31); and 3) intermediate-reaction type (K-type:n = 18). No significant differences were found in metabolite levels of phosphocreatine (normal, MHS, and K-type: 13.20 vs. 13.74 vs. 14.42 nmol/mg wet weight, respectively), creatine (16.30 vs. 16.94 vs. 15.06 nmol/mg wet weight, respectively), adenosine triphospate (3.75 vs. 3.98 vs. 3.89 nmol/mg wet weight, respectively) and lactate (3.73 vs. 3.65 vs. 3.79 nmol/mg wet weight, respectively). It is concluded that analysis of skeletal muscle metabolites cannot be used as a screening test to confirm or exclude MH susceptibility in humans.

In vivo induced malignant hyperthermia in pigs. I. Physiological and biochemical changes and the influence of dantrolene sodium.

The effects of an induced malignant hyperthermia (MH) crisis have been studied in the intact pig. Both physiological and biochemical changes in skeletal muscle were studied. MH was induced with 3% halothane plus a bolus injection of succinylcholine. In the prechallenge period a significant difference was observed in the concentration of certain muscle metabolites, comparing the MH-susceptible (MH+) with the non-susceptible (MH-) pigs. A lower level was measured for phosphocreatine (PCr), inosine monophosphate (IMP) and an increased level of lactate and creatine (Cr) in the susceptible pigs (MH+). The challenge caused a significant reduction of the level of PCr and adenosine in MH+ pigs, compared to the prechallenge period. After administration of dantrolene sodium, a significant decrease was measured in the level of lactate, compared to the prechallenge period as well as during the challenge. In contrast, in the control pigs no significant changes were observed in muscle metabolites, either after induction of MH or after the administration of dantrolene sodium. Enzyme activity determinations of muscle adenylate kinase and adenosine monophosphate (AMP)-deaminase did not show any difference in activity either before or during the MH crisis or after treatment with dantrolene sodium. The earliest physiological change during an induced MH crisis in our study was the rapid increase of the end-tidal CO2. Within 5 min after MH induction, end-tidal CO2 was doubled. It is concluded that the monitoring of the end-tidal CO2 is essential to diagnose MH at a very early stage.

In vivo induced malignant hyperthermia in pigs. III. Localization of calcium in skeletal muscle mitochondria by means of electronmicroscopy and microprobe analysis.

Biceps femoris muscle biopsies of malignant hyperthermia susceptible (MH+) and non-susceptible (MH-) Dutch Landrace pigs were studied ultrastructurally, and exchangeable calcium was demonstrated, using the antimonate precipitation technique in combination with electron probe x-ray microanalysis. Biopsies were taken before and during the administration of halothane-plus-succinylcholine and after dantrolene sodium treatment of the animals. MH+ muscle, taken before the MH triggering, showed a high proportion (about 35%) of cells with supercontraction. Both MH+ and MH- muscle had broad but nearly identical ranges of cell diameter. Core-like structures were occasionally present in muscle from MH+ pigs. Muscle mitochondria from the MH+ pigs accumulated large amounts of calcium in their matrix compartment during the halothane-plus-succinylcholine induced MH crisis. This calcium loading in the course of time caused swelling and structural damage to the mitochondria. Skeletal muscle mitochondria from MH- pigs did not show such a reaction pattern on challenge with halothane and succinylcholine. It is concluded that in MH+ pigs the challenge brings about an increase in myoplasmic free calcium, which is predominantly due to calcium influx from the extracellular fluid. This rise in cytosolic calcium causes the mitochondria to accumulate the cation in an energy-dependent way. These findings are discussed in relation to the diverging halothane and caffeine contraction responses of aerobic type I and anaerobic type II muscle fibres.

In vivo induced malignant hyperthermia in pigs. II. Metabolism of skeletal muscle mitochondria.

The biochemical characteristics of skeletal muscle mitochondria of malignant hyperthermia (MH) susceptible Dutch Landrace pigs have been investigated before and during an MH attack, induced in vivo by halothane plus succinylcholine. The muscle homogenates have a decreased capacity to synthesize ATP and creatine phosphate during the MH period. Muscle mitochondria prepared from susceptible pigs in an MH period consume less oxygen than do mitochondria isolated before the attack, or mitochondria from control pigs during the challenge. The oxidative phosphorylation is not uncoupled during the critical period. The production of CO2 indicates that the in vitro measured capacity of the MH muscle mitochondria correctly reflects the in vivo condition during the MH attack. The restricted synthesis may be caused by a factor, finding expression in the mitochondria themselves, and obtained or activated during the MH attack.