Medical management of painful achalasia: a patient-driven systematic review

Achalasia is a rare esophageal disorder characterized by abnormal esophageal motility and swallowing difficulties. Pain and/or spasms often persist or recur despite effective relief of the obstruction. A survey by UK charity 'Achalasia Action' highlighted treatments for achalasia pain/spasms as a key research priority. In this patient-requested systematic review, we assessed the existing literature on pharmacological therapies for painful achalasia. A systematic review of the literature using Medline, Embase and Cochrane databases was performed to identify studies evaluating pharmacological therapies for achalasia. Methodological quality of included randomized controlled trials was assessed using the Cochrane Risk of Bias tool. In total, 70% (40/57) of survey respondents reported experiencing pain/spasms. A range of management strategies were reported. Thirteen studies were included in the review. Seven were randomized controlled trials. Most studies were >30 years old, had limited follow-up, and focussed on esophageal manometry as the key endpoint. Generally, studies found improvements in lower esophageal pressures with medications. Only one study evaluated pain/spasm specifically, precluding meta-analysis. Overall risk of bias was high. The achalasia patient survey identified that pain/spasms are common and difficult to treat. This patient-requested review identified a gap in the literature regarding pharmacological treatments for these symptoms. We provide an algorithm for investigating achalasia-related pain/spasms. Calcium channel blockers or nitrates may be helpful when esophageal obstruction and reflux have been excluded. We advocate for registry-based clinical trials to expand the evidence base for these patients.

Overinterpretation of findings in diagnostic accuracy studies of infectious diseases

OBJECTIVES

To assess the prevalence of overly positive interpretation - also called 'spin'- of results in diagnostic accuracy studies of infectious diseases and to identify suggestions for improvement.

METHODS

A PubMed search was performed to identify diagnostic accuracy studies of infectious diseases published between January and March 2019. Each article was assessed by two authors independently to identify study characteristics and forms of actual and potential overinterpretation. 'Actual overinterpretation' was defined as conclusions that were not based on the study aims or conclusions that were more favourable than was justified by the study findings. There are other practices that may result in the overinterpretation of study findings and these have been described as 'potential overinterpretation'.

RESULTS

The final analysis included 120 studies. Favourable or promising recommendations were made in the main text of 101 (84%) of the included studies. Evidence of actual overinterpretation (spin) was found in 30 (25%) articles, with 22 studies reporting a conclusion that did not match the study aims and 56 studies with a more positive conclusion in the abstract than in the main text. All analysed studies exhibited at least one form of potential overinterpretation, with was most commonly a lack of sample size calculation (n = 109, 91%) and not reporting a null hypothesis (n = 115, 96%).

CONCLUSIONS

Evidence of overinterpretation of results was found in a third of the included studies. We propose possible interventions to prevent overly positive interpretation of results in diagnostic accuracy studies.

OGC P26 The role of inadequate analgesia in care escalation after oesophagectomy

Background

There is a paucity of data describing the incidence and causes of escalation in level of care after oesophagectomy for cancer. This study aimed to address this, including the description of baseline predisposing variables, and contrasting the profile of care escalation among different surgical approaches to oesophagectomy.

Methods

This was a retrospective analysis of a prospectively maintained database (‘CODA’) at a UK tertiary centre. CODA is a bespoke, high-quality resource, based on senior clinician and data scientist data entry at every stage of the care of the patient's pathway. Complications are updated weekly using the Esophageal Complications Consensus group definition-set. The inclusion criteria were anyone undergoing cancer oesophagectomy between 01/06/2015 and 31/05/2021. Exclusion criteria included patients not on the ‘Enhanced Recovery after Surgery’ pathway and patients with delayed extubation (>2 days post-operatively). Escalation of care was defined as re-admission to the intensive care unit (ICU) or re-intubation on ICU. Standard care at our centre is to maintain epidural analgesia for four days after surgery. Inadequate analgesia was defined as more than one reference to inadequate pain control in the first four days after surgery when the patient deteriorated and required care escalation. Characteristics were compared between patients with and without care escalation, and between patients with and without respiratory failure related to inadequate analgesia.

Results

From 448 oesophagectomys, 42 patients had escalation in their level of care (9.38%). Baseline characteristics between oesophagectomy patients with and without escalation in care were similar, except for escalated patients more likely to have squamous cell carcinoma histology (28.6% vs 14.3%, P = 0.02). 20.0% of 3-phase oesophagectomy patients required care escalation but this just failed to achieve significance when compared with other oesophagectomy approaches (9.6%, P = 0.06). Of escalated patients, 35.7% had respiratory failure related to inadequate analgesia, 33.3% had respiratory failure not related to inadequate analgesia and 31.0% did not have respiratory failure as the reason for care escalation. The major cause of respiratory failure not related to analgesia was pneumonia (6 of 14, 42.9%) and the most frequent cause of non-respiratory failure associated escalation in care was re-operation (5 of 13, 38.5%). Inadequate analgesia was more commonly a contributing factor to escalation in care after left thoracoabdominal oesophagectomy compared to all other approaches (11 of 18 [61.1%] vs 4 of 24 [16.7%], P = 0.003).

Conclusions

The overall rate for escalation in care in this centre was low at 9.38%. This figure may be useful for benchmarking and ongoing research into morbidity after oesophagectomy. There was no clear influence from baseline characteristics or surgical approach on the rate of escalation in care. Respiratory failure contributed to escalation in care for the majority of patients. Our data indicates that left thoraco-abdominal incisions are particularly sensitive to inadequate analgesia, which suggests that effective analgesic rescue plans are especially critical after this type of oesophagectomy.

Vestibular neuronitis after COVID-19 vaccination

A woman in her 50s presented with acute vertigo and vomiting within 72 hours of receiving the Pfizer-BioNTech COVID-19 vaccine. The only neurological deficit was an impaired vestibulo-ocular reflex with horizontal nystagmus. The patient was subsequently diagnosed with vestibular neuronitis. She was managed symptomatically with prochlorperazine and betahistine, and underwent vestibular rehabilitation for 6 weeks. She made a full recovery and experienced no further symptoms. She received the second dose of the vaccine without complications.

This case demonstrates a temporal association between COVID-19 vaccination and vestibular neuronitis. Neurological adverse events are rare but recognised side effects of COVID-19 vaccines and healthcare professionals should be aware of them. This ensures timely management of patients with such presentations. Treatment should be the same as for non-vaccine-associated vestibular neuronitis. The nature of the relationship between COVID-19 vaccination and vestibular neuronitis remains unclear and patients therefore require investigations to exclude other recognised causes of vestibular neuronitis.

Establishing a novel community-focussed lactation support service: a descriptive case series

Background

Although breastfeeding is widely acknowledged as protecting both infant and maternal health postnatally, a partial or complete shortfall of maternal milk can occur for a range of reasons. In this eventuality, the currently available options for feeding infants are screened donor human milk (DHM), infant formula or unscreened shared human milk. In the UK, DHM has only been widely available in specific clinical contexts for the last 40 years, mainly to reduce the risk of necrotising enterocolitis in extremely preterm infants alongside optimal support for maternal lactation and breastfeeding. The Hearts Milk Bank (HMB) was established in 2017 as an independent, non-profit human milk bank that aimed to ensure equitable, assured access to screened DHM for neonatal units. As a result of the generosity of mothers, a surplus of DHM rapidly became available and together with lactation support, has since been provided to families with a healthcare referral. This programme has now been formalised for families facing lactational challenges, and DHM stocks are permanently maintained to meet their needs.

Case series

This case series describes the clinical paths of four families who accessed lactation support and DHM from the HMB, along with a description of the process for community provision. To date, the HMB has supported over 300 families. Working collaboratively with key stakeholders, the HMB team has developed a prioritisation strategy based on utilitarian ethical models, protocols that ensure safe handling and appropriateness of use, broader donor recruitment parameters that maintain safety with a pragmatic approach for full term healthy infants, and a process to ensure parents or carers have access to the knowledge needed to give informed consent and use DHM appropriately.

Conclusions

Stakeholders, including parents, healthcare professionals, and milk banks, will need to discuss priorities for both DHM use and research gaps that can underpin the equitable expansion of services, in partnership with National Health Service (NHS) teams and third-sector organisations that support breastfeeding and maternal mental health.

Symptomatic, biochemical and radiographic recovery in patients with COVID-19

Background

The symptoms, radiography, biochemistry and healthcare utilisation of patients with COVID-19 following discharge from hospital have not been well described.

Methods

Retrospective analysis of 401 adult patients attending a clinic following an index hospital admission or emergency department attendance with COVID-19. Regression models were used to assess the association between characteristics and persistent abnormal chest radiographs or breathlessness.

Results

75.1% of patients were symptomatic at a median of 53 days post discharge and 72 days after symptom onset and chest radiographs were abnormal in 47.4%. Symptoms and radiographic abnormalities were similar in PCR-positive and PCR-negative patients. Severity of COVID-19 was significantly associated with persistent radiographic abnormalities and breathlessness. 18.5% of patients had unscheduled healthcare visits in the 30 days post discharge.

Conclusions

Patients with COVID-19 experience persistent symptoms and abnormal blood biomarkers with a gradual resolution of radiological abnormalities over time. These findings can inform patients and clinicians about expected recovery times and plan services for follow-up of patients with COVID-19.

Use of donor human milk in nonhospitalized infants: An infant growth study

When mother's own milk (MOM) is unavailable or insufficient, donor human milk (DHM) is recommended as the next best alternative for low birthweight infants. DHM use for healthy, term infants is increasing, but evidence for growth and tolerability is limited. This retrospective study evaluated growth in term infants in the community who received DHM from a UK milk bank. Mothers of infants receiving DHM between 2017 and 2019 were contacted (n = 49), and 31 (63.2%) agreed to participate. Fourteen infants received DHM as a supplement to other feeds (MOM and/or infant formula) and 17 were exclusively fed DHM where breastfeeding was impossible (range: 3–6 weeks). Growth was assessed by deriving z‐scores using the WHO standard for infant growth and compared with 200 exclusively breastfed infants. Multivariate regression analysis revealed no feeding method‐specific association between z‐score and age, nor between weight and age, suggesting that z‐scores and growth velocity were not affected by feeding exclusive MOM, supplemental DHM or exclusive DHM. DHM was well‐tolerated with no adverse events that led to early cessation. After receiving supplemental DHM group, 63% of infants whose mothers had no physical barrier to breastfeeding (5/8 infants) were exclusively breastfed. This novel study reports adequate growth outcomes of healthy nonhospitalized infants receiving DHM, either as the sole milk source or supplement. Prospective studies are needed to confirm whether DHM is a suitable feeding alternative for term infants in the community, optimal durations, as well as the impact of DHM availability on breastfeeding rates and maternal mental health.

DHM recipients were compared with the who infant growth standard (World Health Organization, 2020) by deriving z‐scores. The WHO Anthro Macro (World Health Organization, 2011 ) was used to calculate weight‐for‐age, length‐for‐age and head circumference‐for‐age z‐scores; z‐scores are the standard deviation of an infant's anthropometric measurements when compared with the WHO standard for infant growth and are gender and age specific.

Intermittent warm blood versus cold crystalloid cardioplegia for myocardial protection: a propensity score-matched analysis of 12-year single-center experience

Objectives:

This study analyzes the efficacy in myocardial protection of two types of cardioplegia solutions, namely, blood and crystalloid cardioplegia, both given intermittently in patients undergoing coronary artery bypass grafting (CABG).

Methods:

Adult patients undergoing primary isolated coronary artery bypass grafting between January 1998 and January 2011 with cardiopulmonary bypass, using either blood or crystalloid cardioplegia, were identified in our database. Propensity score matching was performed to create comparable patient groups. Multivariate logistic regression analysis was performed to identify independent risk factors for perioperative myocardial damage. The primary endpoint of the study was the maximum creatine kinase-MB (CK-MB) value within 5 days postoperatively with a cut-off point of 100 U/L. Early mortality and perioperative low cardiac output syndrome in both groups were compared.

Results:

The study included 7138 CABG patients: 3369 patients using crystalloid cardioplegia and 3769 using blood cardioplegia. After propensity score matching, 2585 patients per study group remained for the analysis. Wilcoxon signed-rank test revealed significantly higher CK-MB levels in patients operated with the use of blood cardioplegia. Multivariate regression analysis identified blood cardioplegia as an independent risk factor for elevated CK-MB levels. However, it was associated with lower aspartate aminotransferase (AST) levels. The type of cardioplegia had no influence on early mortality, postoperative low cardiac output syndrome or intensive care unit stay.

Conclusions:

Blood cardioplegia was identified as an independent risk factor for elevated levels of CK-MB after CABG, but was associated with lower AST levels. The authors conclude that the type of cardioplegia had no significant influence on clinical outcome.

Clinical outcome of the PAS-Port® proximal anastomosis system in off-pump coronary artery bypass grafting in 201 patients

AIM

The PAS-Port® Proximal Anastomosis System (Cardica, Inc, Redwood City, CA, USA) has been used worldwide since March 2003. The objective of the present study was to evaluate the clinical outcome of the PAS-Port® Proximal Anastomosis System.

METHODS

All the patients who underwent off-pump coronary artery bypass grafting in the Catharina Hospital Eindhoven between August 2006 and April 2010 were included in a non-randomized retrospective case-control study, if they had at least one proximal vein graft anastomosis. Study end-points consisted of overall survival, coronary reintervention and postoperative stroke.

RESULTS

The study included 312 patients (201 cases, 111 controls). After 36 months of follow-up there was no difference in survival between cases and controls (92.2% vs. 93.7%, P=0.52). No significant difference could be detected between cases and controls with respect to overall coronary reintervention-free survival (93% vs. 96.4%, P=0.20) and freedom from coronary reintervention due to proximal vein graft failure (98% vs. 100% P=0.14). The use of the PAS-Port system could not be identified as an independent risk factor of coronary reintervention (p=0.21). Postoperative stroke rates of cases and controls (2% vs. 0.9%, P=0.42) were comparable.

CONCLUSION

The clinical outcomes in patients treated with the PAS-Port® Proximal Anastomosis System were satisfactory compared with those treated with the conventional hand-sewing technique. The use of the PAS-Port system was not associated with higher adverse outcome in terms of overall survival, stroke, coronary reintervention-free survival and freedom from reintervention due to proximal vein graft failure.

Post-operative Atrial Fibrillation - Pathophysiology, Treatment and Prevention

Atrial fibrillation occurring after cardiac surgery has been the subject of intensive research over the past decades. However, the incidence remains high, despite numerous preventive and treatment strategies. In addition, several reports show that the impact of post-operative atrial fibrillation (POAF) is high. It is an independent risk factor for mortality after several years. These findings make clear that the pathophysiology of POAF is not fully understood and POAF-associated risks to some extent might be underestimated. On the one hand, excessive triggers during the acute post operative phase after cardiac surgery might initiate AF even in atria with low vulnerability. On the other hand, many patients undergoing surgery have an atrial substrate at the time of operation promoting AF not only in the post-operative phase but also in the days and weeks thereafter. Progress in our understanding of the AF mechanisms in general has provided valuable insights into processes involved in atrial structural remodeling due to advanced age, hypertension, obesity, and congestive heart failure. These patient characteristics strongly contribute to cardiac disease, predict POAF and likely have an impact on the risk of thrombus formation in the weeks and months after cardiac surgery. For a better understanding of the mechanisms involved, it is important to not only recognize the occurrence of POAF by continuous monitoring after surgery, but also to identity the extent of atrial vulnerability to AF in these patients.

[Acute abdominal pain and fever in a young woman as the first symptoms of lymphangioleiomyomatosis]

A previously healthy 28-year-old woman presented to the emergency clinic with acute severe abdominal pain and high fever. A diagnostic laparoscopy was performed, during which a large retroperitoneal tumour was found. A CT-scan of the abdomen and thorax confirmed the presence of a retroperitoneal mass but also revealed multiple renal angiomyolipomas and extensive cystic lesions in all lung fields. Based on these findings, the diagnosis lymphangioleiomyomatosis (LAM) was suspected, and later confirmed by histological examination of a biopsy specimen. The acute abdomen and fever appeared to have been caused by a Streptococcus agalactiae infection of the retroperitoneal lymphangiomyoma, which was treated with intravenous antibiotics. LAM is a very rare disease affecting mostly women of childbearing age and presenting almost exclusively with pulmonary symptoms. This is the first description of LAM presenting with an acute surgical abdomen and fever due to infection of a lymphangiomyoma.

[Bilateral hypoglossal nerve palsy following intubation]

Hypoglossal nerve palsy following intubation is a rare complication that can be reversible depending on the extent of nerve damage. A 63-year-old male with a sigma carcinoma was repeatedly intubated orotracheally due to postoperative complications. After the fourth intubation, bilateral, complete hypoglossal nerve palsy with severe dysarthria and swallowing disability was observed. A percutaneous endoscopic gastrostomy tube was inserted for nutrition and to prevent aspiration. Cerebral MRI showed no pathological findings, particularly in the brainstem. Electromyographic studies revealed pathological spontaneous activity of both glossal muscles without any motor unit potential consistent with an axonal lesion of both hypoglossal nerves. Nevertheless, complete clinical and electromyographical recovery occurred within 7 months. The bilateral hypoglossal nerve palsy in our patient was probably due to mechanical alteration during intubation, leading to axonotmesis. Hypoglossal nerve palsy following intubation might have a favourable prognosis as long as continuity of the nerve sheath is maintained.

Bedside assessment of cerebral perfusion reductions in patients with acute ischaemic stroke by near-infrared spectroscopy and indocyanine green

OBJECTIVE

To detect perfusion reductions in patients with acute cerebral infarcts using near-infrared spectroscopy (NIRS) with indocyanine green (ICG) as tracer.

METHODS

Kinetics of an intravenous bolus of ICG were monitored by NIRS in 13 patients with acute infarction in the territory of the middle cerebral artery (mean (SD) age, 62.2 (13.0) years) and 12 controls (64.2 (9.1) years) at 2.8 (2.8) days after onset. NIRS optodes were placed bitemporally, with an interoptode distance of 4-5 cm. Absolute concentration changes in ICG were calculated. The following were assessed: time to peak, maximum ICG concentration, time interval between 0% and 100% maximum ICG concentration (interval), rise time (time between 10% and 90% ICG maximum), slope (maximum Delta ICG/interval), and blood flow index (BFI = maximum Delta ICG/rise time) of each hemisphere. Intraindividual differences were calculated between the two hemispheres.

RESULTS

Patients with ischaemic stroke had increased time to peak (p<0.01), interval (p<0.01), and rise time (p<0.01), while maximum ICG concentration (p<0.03), slope (p<0.01), and BFI (p<0.01) were diminished at the site of infarction compared with the unaffected hemisphere. In stroke patients, intraindividual differences in time to peak (p<0.001), interval (p<0.001), rise time (p = 0.001), maximum ICG concentration (p<0.02), slope (p<0.001), and BFI (p<0.001) were greater than in the controls, with excellent sensitivity and specificity for Delta time to peak (100% and 100%, respectively) and Delta time interval (100% and 91.7%).

CONCLUSIONS

Measurement of interhemispheric differences in ICG kinetics by NIRS detects perfusion reductions in patients with acute middle cerebral artery infarction. This non-invasive bedside test is rapid, repeatable, without major side effects, and avoids transportation of critically ill patients.

Short-term dynamics of coherence between respiratory movements, heart rate, and arterial pressure fluctuations in severe acute brain disorders

In our previous study, healthy volunteers showed considerable short-term dynamics and patterns of the coherence of high time resolution between respiratory movements (RESP), heart rate fluctuations (HRF), and arterial blood pressure fluctuations (BPF). These are physiological indicators of autonomic short-term coordination mediated mainly by the brainstem which could be impaired in severe brain disorders. We hypothesized a direct or indirect impairment of these functions by these disorders and examined these patterns in 16 patients suffering from severe brain disorders. We calculated partial and ordinary coherence sequences and found almost the same patterns of coherence sequences as in healthy volunteers, but a distinctly reduced frequency of pattern incidence in patients (2.8+/-1.5/10 min/patient and 9.5+/-2.8/10 min/subject, P<0.05). Furthermore, there is a significantly smaller frequency of HRF-related patterns in patients with poor outcome, compared with those in patients with good outcome (1.8+/-0.8/10 min/patient and 4.5+/-2.7/10 min/patient, P<0.05). We conclude that severe brain disorders reduce physiological short-term dynamics of autonomic coordination patterns in the mean values of patients, but not in every patient.

Short-term dynamics of relative coordination between respiratory movements, heart rate and arterial pressure fluctuations within the respiratory frequency range

The possible linear short-term coordination between respiratory movements (RESP), heart rate fluctuations (HRF), and arterial blood pressure fluctuations (BPF) in conscious human beings has not yet been investigated because of the restricted time resolution of conventional time series analysis. At present, this short-term dynamics as an expression of relative coordination can be quantified by newly developed adaptive autoregressive modeling of time series using Kalman filtering. Thus, in 6 conscious healthy volunteers, RESP, HRF, and BPF were recorded during 10 min in the supine position, at rest and during paced breathing. A considerable part of calculated ordinary and partial coherence sequences of short-term resolution between RESP and HRF, RESP and BPF, and partially between HRF and BPF showed patterns varying in time that could be correlated to changes between gradual coordinations (coherence changing between 0.40 and 0.95). They were more seldom complete or absent. There were mostly opposite changes between partial coherence sequences RESP-HRF/BPF and RESP-BPF/HRF demonstrating competitive behavior between these coordinations. Paced breathing did not essentially affect any observed characteristics. Therefore, these coherence dynamics are not essentially dependent on voluntary breathing movements. We conclude that to a different extent these linear and changing couplings between RESP, HRF, and BPF in conscious human beings exhibit properties of short-term complete and more frequently gradual coordinations showing dynamics that can not be determined by conventional methods.

Effect of CYP3A inhibition on vesnarinone metabolism in humans

OBJECTIVE

To identify the cytochrome P450 (CYP) enzymes involved in the conversion of vesnarinone to it main primary metabolite OPC-18692 and to investigate the effect of CYP3A inhibition on the pharmacokinetics of vesnarinone in vivo.

METHODS

Formation of the primary vesnarinone metabolite OPC-18692 was measured in microsomes from AHH-1 TK +/- cells heterologously expressing CYP1A1, CYP1A2, CYP2A6, CYP2C9, CYP2D6, CYP2E1, or CYP3A4. The pharmacokinetics of vesnarinone and OPC-18692 were defined for 12 health white men after oral administration of 60 mg vesnarinone before and after CYP3A inhibition, which was produced by pretreatment with erythromycin. CYP3A inhibition was verified with erythromycin breath test.

RESULTS

In vitro, expressed CYP2E1 and CYP3A4 produced significant amounts of OPC-18692 with the higher formation rate observed by CYP3A4 (12.3 pmol/pmol VYP3A4 per 2 hours versus 1 pmol/pmol CYP2E1 per 2 hours). In vivo, the area under the concentration-time curve extrapolated to infinity (AUC[infinity]) of vesnarinone after pretreatment with erythromycin increased from 133 +/- 26 micrograms.hr/ml to 202 +/- 47 micrograms.hr/ml (p < 0.001), and the half-life increased from 36.5 +/- 9.6 hours to 46.2 +/- 9.2 hours (p < 0.01). Clearance decreased from 372 +/- 68 ml/min to 256 +/- 49 ml/min (p < 0.001). These changes in the disposition of vesnarinone were accompanied by a decrease in plasma concentration of the metabolite OPC-18692 so that the AUC(0-48) was reduced from 1311 +/- 513 micrograms.hr/ml to 850 +/- 148 micrograms.hr/ml (p < 0.001). The total amount of vesnarinone excreted in the urine up to 168 hours after administration increased after erythromycin pretreatment (p < 0.001). Although renal clearance did not change, OPC-18692 was not detectable in the urine. The erythromycin breath test showed significant inhibition after pretreatment with erythromycin (p < 0.001).

CONCLUSIONS

CYP2E1 and CYP3A4 are involved in the phase I metabolism of vesnarinone. Inhibition of CYP3A activity in vivo increases the plasma concentration of vesnarinone and delays its elimination in humans so that monitoring of its plasma levels may be helpful in preventing concentration-related toxicity when CYP3A activity is impaired. Whether CYP3A induction and altered CYP2E1 activity may also change the in vivo disposition of vesnarinone remains to be determined.

Risk indicators for neonatal early-onset GBS-related disease. A case-control study

Risk indicators play an important role in the active prevention of neonatal Early-Onset GBS-related Disease (EOD). We studied the associations between potential risk indicators and the occurrence of EOD by means of a case-control study. All cases of EOD delivered in the Academic Medical Centre in Amsterdam between January 1988 and December 1995 were included. For each case we selected 3 controls, matched for date and time of birth. The association between continuous risk indicators and the occurrence of EOD was assessed using spline functions. Multivariable logistic regression analysis was performed to determine which risk indicators contributed independently. Forty-one cases were compared with 123 controls. In the multivariable analysis, gestational age < 37 weeks and intrapartum temperature > or = 37.4 degrees C showed to be statistically significant risk indicators for EOD, with odds ratios of 2.5 per week gestation and 1.6 per 0.1 degree C, respectively. After cesarean section the risk of EOD was significantly decreased (OR 0.13). Of the other potential risk indicators only prelabor rupture of membranes showed an increased risk, although the association was not statistically significant. Prolonged duration of ruptured membranes had no additional merit. Risk indicators that should be taken into account in strategies to prevent EOD are increased maternal temperature and decreased gestational age.