Precision of vacuum cup placement and its association with subgaleal hemorrhage and associated morbidity in term neonates

PURPOSE

To evaluate whether the precision of vacuum cup placement is associated with failed vacuum extraction(VE), neonatal subgaleal hemorrhage(SGH) and other VE-related birth trauma.

METHODS

All women with singleton term cephalic fetuses with attempted VE were recruited over a period of 30 months. Neonates were examined immediately after birth and the position of the chignon documented to decide whether the cup position was flexing median or suboptimal. Vigilant neonatal surveillance was performed to look for VE-related trauma, including subgaleal/subdural hemorrhages, skull fractures, scalp lacerations. CT scans of the brain were ordered liberally as clinically indicated.

RESULTS

The VE rate was 5.89% in the study period. There were 17(4.9%) failures among 345 attempted VEs. Thirty babies suffered from subgaleal/subdural hemorrhages, skull fractures, scalp lacerations or a combination of these, giving an incidence of VE-related birth trauma of 8.7%. Suboptimal cup positions occurred in 31.6%. Logistic regression analysis showed that failed VE was associated with a non-occipital anterior fetal head position (OR 3.5, 95% CI 1.22-10.2), suboptimal vacuum cup placement (OR 4.13, 95% CI 1.38-12.2) and a longer duration of traction (OR 8.79, 95% CI 2.13-36.2); while, VE-related birth trauma was associated with failed VE (OR 3.93, 95% CI 1.08-14.3) and more pulls (OR 4.07, 95% CI 1.98-8.36).

CONCLUSION

Suboptimal vacuum cup positions were related to failed VE but not to SGH and other vacuum-related birth trauma. While optimal flexed median cup positions should be most desirable mechanically to effect delivery, such a position does not guarantee prevention of SGH.

Prenatal Diagnosis and Pregnancy Outcomes of Fetuses With Orofacial Cleft: A Retrospective Cohort Study in Two Centres in Hong Kong

OBJECTIVE

To evaluate the local incidence of orofacial cleft (OFC) encountered in fetal morphology scan and prenatal diagnosis, genetic etiology of fetuses with or without other structural abnormalities, and their pregnancy outcomes.

DESIGN

Retrospective cohort study.

SETTING

Two maternal fetal medicine units, tertiary hospitals, Hong Kong.

PARTICIPANTS

All pregnant women with antenatal diagnosis of fetal OFC between January 2016 and December 2020 (N = 66).

RESULTS

OFC has an incidence of 0.13% among pregnancies in Hong Kong and 28.8% (19/66) were syndromic cleft that exhibited other fetal structural anomalies. There were 55 cases (84.6%) who opted for invasive prenatal diagnostic testing. Genetic defects were identified in 25.8% (17/66) of this cohort, including 14 pathogenic variants. The detection rate in the syndromic cases is 68.4% (13/19) which was significantly higher than 8.5% (4/47) among non-syndromic cases. Aneuploidies would be the most common cause, accounting for 9.1% (6/66). Chromosomal microarray analysis (CMA) provided an incremental diagnostic yield of 6.1% compared to conventional karyotyping. A total of 29 live births including 3 cases of a variant of uncertain significance and 26 cases without genetic abnormalities detected have continued pregnancy to birth. There were 87.5% (21/24) without detectable pathogenic genetic abnormality reported good long-term outcomes. The chance of OFC fetuses having a good long-term outcome was significantly higher if no genomic variant was detected (P < .001).

CONCLUSIONS

Invasive prenatal tests with CMA should be offered to pregnancies with OFC regardless of the type. It has provided incremental diagnostic yield over conventional karyotyping and helped in prenatal and genetic counseling. A negative result in non-syndromic OFC favors couples to keep the pregnancy.

Evaluating the diagnostic properties of the Whooley questionnaire as a case-finding instrument for depression among Chinese women during and after pregnancy

Purpose: There is a rising prevalence in undetected perinatal depression in many countries, more effort in screening and early identification of perinatal depression is needed. While the Whooley questionnaire is the recommended case-finding strategy for perinatal depression, there is no validated Chinese version. The aim was to evaluate the diagnostic accuracy and stability of the translated Chinese Whooley questionnaire against gold standard measurement during and early after pregnancy.Materials and Methods: This observational study recruited 131 pregnant women from an antenatal clinic in Hong Kong from September 2019 to May 2020. We translated the Whooley questionnaire in Chinese and evaluated self-reported responses against an interviewer-assessed diagnostic standard (DSM-IV criteria) in 107 women at 26-28 gestational weeks. We calculated sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio, with DSM-IV diagnosis as the gold standard.Results: The Chinese Whooley questions had a sensitivity of 79% (95% CI 54.4-93.9), a specificity of 97% (95% CI 90.4-99.3), a positive likelihood ratio of 23.2 (95% CI 7.4-72.1) and a negative likelihood ratio of 0.2 (95% CI 0.1-0.5) in identifying perinatal depression.Conclusion: The translated Chinese Whooley questionnaire has an acceptable diagnostic accuracy in identifying perinatal depression. It can be implemented in health services among Cantonesespeaking Chinese population.

A prospective study on neonatal ophthalmic injuries associated with forceps delivery

BACKGROUND

Assisted delivery by forceps is needed to expedite vaginal delivery in certain maternal and fetal conditions. The aim of this study was to evaluate the incidence and the extent of ophthalmological injuries in neonates after forceps delivery.

METHODS

Women with cephalic fetuses delivered vaginally by forceps from July 2020 to June 2022 were recruited prospectively. Ophthalmologists would be consulted when there were signs of external ophthalmic injuries, such as periorbital forceps marks or facial bruising. Demographic data, pregnancy characteristics, delivery details, and perinatal outcomes were evaluated to identify any associated risk factors for neonatal ophthalmological injuries.

RESULTS

A total of 77 forceps deliveries were performed in the study period, in which 20 cases (26%) required ophthalmological consultations. There were more right or left occipital fetal head positions in the group requiring ophthalmological assessment than those that did not require assessment (35% vs 12.3% [P = 0.023]). The degree of moulding of the fetal head was more marked in the former group (65% vs 28% [P = 0.001]). The overall incidence of detectable ophthalmological lesions was 16.9% (13/77). All ophthalmic injuries were mild, and most resolved with conservative management.

CONCLUSIONS

In our study cohort, external ophthalmic injuries were common after forceps delivery. We recommended ophthalmological consultation in newborns delivered by forceps with evidence of compressive trauma to rule out serious ophthalmological trauma.

Risk factors for postpartum haemorrhage in twin pregnancies and haemorrhage severity

INTRODUCTION

This study evaluated risk factors for postpartum haemorrhage (PPH) in twin pregnancies, particularly factors associated with major PPH (blood loss of >1000 mL), to facilitate identification of high-risk twin pregnancies.

METHODS

This retrospective cohort study included all women with twin pregnancies who delivered at a tertiary obstetric unit in Hong Kong from 2009 to 2018 and experienced PPH (blood loss of ≥500 mL). Postpartum haemorrhage was classified using three thresholds for blood loss volume: ≥500 mL (all PPH), >1000 mL (major PPH), and >1500 mL (severe PPH). Risk factors for each threshold of PPH were analysed.

RESULTS

In total, there were 680 twin pregnancies. The overall incidence of all PPH (≥500 mL) in this cohort was 27.8%, including minor PPH (500-1000 mL, 20.1%), major but not severe PPH (1001-1500 mL, 4.4%), and severe PPH (>1500 mL, 3.2%). Logistic regression analysis showed that general anaesthesia and the use of oxytocin were significant risk factors for all PPH (≥500 mL); general anaesthesia, in vitro fertilisation, antepartum haemorrhage, placental abruption, and placenta praevia were significant risk factors for major PPH (>1000 mL); in vitro fertilisation, placenta praevia, and obesity were significant risk factors for severe PPH (>1500 mL).

CONCLUSION

Women with twin pregnancies who have obesity, conception by in vitro fertilisation, or placenta praevia exhibit a high risk of severe PPH. They should deliver in obstetric units with readily available blood product transfusions and the appropriate expertise for prompt management of severe PPH.

Implementation of Public Funded Genome Sequencing in Evaluation of Fetal Structural Anomalies

With the advancements in prenatal diagnostics, genome sequencing is now incorporated into clinical use to maximize the diagnostic yield following uninformative conventional tests (karyotype and chromosomal microarray analysis). Hong Kong started publicly funded prenatal genomic sequencing as a sequential test in the investigation of fetal structural anomalies in April 2021. The objective of the study was to evaluate the clinical performance and usefulness of this new service over one year. We established a web-based multidisciplinary team to facilitate case selection among the expert members. We retrospectively analyzed the fetal phenotypes, test results, turnaround time and clinical impact in the first 15 whole exome sequencing and 14 whole genome sequencing. Overall, the molecular diagnostic rate was 37.9% (11/29). De novo autosomal dominant disorders accounted for 72.7% (8/11), inherited autosomal recessive disorders for 18.2% (2/11), and inherited X-linked disorders for 9.1% (1/11). The median turnaround time for ongoing pregnancy was 19.5 days (range, 13-31 days). Our study showed an overall clinical impact of 55.2% (16/29), which influenced reproductive decision-making in four cases, guided perinatal management in two cases and helped future family planning in ten cases. In conclusion, our findings support the important role of genome sequencing services in the prenatal diagnosis of fetal structural anomalies in a population setting. It is important to adopt a multidisciplinary team approach to support the comprehensive genetic service.

Knowledge, attitudes, and behaviours of pregnant women towards COVID-19: a cross-sectional survey

INTRODUCTION

This study investigated the knowledge, attitudes, and behaviours of pregnant women towards coronavirus disease 2019 (COVID-19), as well as obstetric services provided by public hospitals (eg, universal screening) during the pandemic.

METHODS

This cross-sectional survey was performed in the antenatal clinics of Kowloon East Cluster, Hospital Authority. Questionnaires were distributed to pregnant women for self-completion during follow-up examinations.

RESULTS

In total, 623 completed questionnaires were collected from 28 July 2020 to 13 August 2020. Within this cohort, 83.1% of the women expressed high levels of worry (41.9% very worried and 41.3% worried) about contracting COVID-19 during pregnancy, 70.5% believed that maternal COVID-19 could cause intrauterine infection of their fetuses, and 84.3% objected to banning husbands from accompanying wives during labour and delivery. Most women (80.6%) agreed with universal screening for COVID-19 at certain points during pregnancy. Logistic regression modelling showed that women who were very worried about contracting COVID-19 (P=0.005) and women in their third trimester of pregnancy (P=0.009) were more likely to agree with universal screening during pregnancy; women with higher income (P=0.017) and women who planned to deliver in a private hospital (P=0.024) were more likely to disagree with such screening.

CONCLUSION

Pregnant women expressed high levels of worry about contracting COVID-19 during pregnancy; universal screening during pregnancy was acceptable to a large proportion of our participants. Efforts should be made to specifically include pregnant women when launching any population screening programme for COVID-19.

Impact of foeto-maternal resuscitation and perimortem caesarean section simulation training: An opinion survey of healthcare participants

Background:

The incidence of maternal cardiac arrest is rising in recent years. Medical staff generally lack the experience of performing resuscitation on pregnant patients. Maternal cardiac arrest and perimortem caesarean section simulation training was newly introduced in the Advanced Life Support in Obstetrics provider courses in Hong Kong since April 2021.

Objective:

To evaluate the course participants’ opinions on maternal cardiac arrest simulation training.

Methods:

A questionnaire survey was conducted for all participants in the Advanced Life Support in Obstetrics provider course in April 2021 to assess their opinions on the usefulness of this training.

Results:

There were four Advanced Life Support in Obstetrics provider courses in April 2021 with 36 participants in each course, and 137 questionnaires were received at the end of the course. The response rate was 137/144 (95.1%). After excluding the questionnaires with incomplete information, 134 questionnaires were included for final analysis. Almost all of the participants agreed that the maternal cardiac arrest simulation training could help them in their work (97.8%), could improve their knowledge and skill (98.5%) and could improve team training and co-ordination (97.0%). The majority of them (97.0%) felt more confident in managing maternal cardiac arrest after the training, and 97.8% of participants felt that the perimortem caesarean section model was useful for training. Around 80% of the participants would recommend this course to their colleagues. There were no significant differences in opinions on the usefulness of this training among participants with regard to their specialty, whether they were doctors or nurses, their years of experience and the specific hospital settings.

Conclusions:

Maternal cardiac arrest simulation training was highly valued by all levels of obstetric, emergency medicine and anaesthesia staff in both public and private hospitals.

Chromosomal abnormalities and neurological outcomes in fetal cerebral ventriculomegaly: a retrospective cohort analysis

INTRODUCTION

This study investigated the incidences of chromosomal abnormalities and the neurological outcomes according to the degree of fetal cerebral ventriculomegaly.

METHODS

All women with antenatal ultrasound diagnosis of fetal cerebral ventriculomegaly were retrospectively identified from two maternal-fetal medicine units in Hong Kong from January 2014 to December 2018. Degrees of fetal ventriculomegaly were classified as mild (10-11.9 mm), moderate (12-14.9 mm), or severe (≥15 mm). Genetic investigation results were reviewed, including conventional karyotyping and chromosomal microarray analysis (CMA); correlations between chromosomal abnormalities and the degree of fetal ventriculomegaly were explored. The neurological outcomes of subsequent live births were analysed to identify factors associated with developmental delay.

RESULTS

Of 84 cases (ie, pregnant women and their fetuses) included, 46 (54.8%) exhibited isolated fetal ventriculomegaly, 55 (65.5%) had mild cerebral ventriculomegaly, and 29 (34.5%) had moderate or severe cerebral ventriculomegaly. Overall, 20% (14/70) of cases had chromosomal abnormalities. Moreover, 12% (3/25) of mild isolated ventriculomegaly cases had abnormal karyotype or CMA results. The CMA provided an incremental diagnostic yield of 8.6% (6/70), compared with conventional karyotyping; 4.3% exhibited pathogenic variants and 4.3% exhibited variants of uncertain significance. Among the 53 live births in the cohort, fewer cases of mild isolated ventriculomegaly were associated with developmental delay than more severe isolated ventriculomegaly (9.7% vs 41.7%, P<0.03).

CONCLUSIONS

Chromosomal microarray analysis testing should be offered to all women with fetal cerebral ventriculomegaly, including women with isolated mild ventriculomegaly. The incidence of developmental delay after birth increases with the degree of prenatal cerebral ventriculomegaly.

Knowledge, perception and expectation of management of hepatitis B infection among pregnant hepatitis B carriers in Hong Kong

Lack of awareness regarding the risk of hepatitis B virus (HBV) infection and the interventions available during pregnancy among the pregnant carriers may influence their willingness and adherence to the management. This study assessed the knowledge, perception and expectation of HBV infection among pregnant HBV carriers in Hong Kong. A prospective multicentre cross-sectional questionnaire study was carried out between August 2019 and April 2021. The general knowledge on HBV, perception and expectation, and interventions to reduce vertical transmission were questioned. Obtaining ≥70% correct answers was defined as having sufficient knowledge. 422 (82.7%) were known carriers. Only 18.4% of women had sufficient overall knowledge. The correct answer rates and percentage of sufficient knowledge were statistically lower for HBV knowledge specific to pregnancy compared with general knowledge (42.5% vs. 58.5%, p < 0.001; 8.8% vs. 30.2%, p < 0.001 respectively). Multiple logistic regression showed higher education and receiving HBV medical care within a year prior to pregnancy were associated with sufficient overall (OR 3.46; 95% CI 2.05-5.83 and OR 2.76; 95% CI 1.62-4.7, p < 0.001), and general knowledge (OR 2.86; 95% CI 1.81-4.51 and OR 2.14; 95% CI 1.33-3.44, p < 0.05). 298 (58.4%), 357 (70.0%) and 150 (29.4%) women believed they should receive care by obstetrician, hepatologist or general practitioner respectively. 46.9% did not want to initiate antiviral treatment due to the cost, perceived teratogenicity and maternal side effects. The knowledge of HBV among pregnant carriers in Hong Kong was poor despite the majority of them being aware of their carrier status prior to the pregnancy.

Comparison of modeling accuracy between Radixact®and CyberKnife®Synchrony®respiratory tracking system

Synchrony Respiratory Tracking system adapted from CyberKnife has been introduced in Radixact to compensate the tumor motion caused by respiration. This study aims to compare the modeling accuracy of the Synchrony system between Radixact and CyberKnife. Two Synchrony plans based on fiducial phantoms were created for CyberKnife and Radixact, respectively. Different respiratory motion traces were used to drive a motion platform to move along the superoinferior and left-right direction. The cycle time and the amplitude of target/surrogate motion of one selected motion trace were scaled to investigate the dependence of modeling accuracy on the motion characteristic. The predicted target position, the correlation error, potential difference (Radixact only) and standard error (CyberKnife only) were extracted from raw data or log files of the two systems. The modeling accuracy was evaluated by calculating the root-mean-square (RMS) error between the predicted target positions and the input motion trace. A threshold T95 within which 95% of the potential difference or the standard error lay was defined and evaluated. Except for the motion trace with a small amplitude and a good (linear) correlation between target and surrogate motion, Radixact showed smaller RMS errors than CyberKnife. The RMS error of both systems increased with the motion amplitude and showed a decreasing trend with the increasing cycle time. No correlation was found between the RMS error and the amplitude of surrogate motion. T95 could be a good estimator of modeling accuracy for CyberKnife rather than Radixact. The correlation error defined in Radixact were largely affected by the number of fiducial markers and the setup error. In general, the modeling accuracy of the Radixact Synchrony system is better than that of the CyberKnife Synchrony system under unfavorable conditions.

Use of balloon tamponade in management of vaginal laceration and its possible complication of urinary stress incontinence: a case report

BACKGROUND

Postpartum haemorrhage from vaginal lacerations can occasionally be refractory to suturing and vaginal packing. Bakri uterine balloon has been widely adopted to stop uterine bleeding, but its use to stop bleeding in vaginal lacerations and its possible complications have seldom been reported.

CASE PRESENTATION

We report a patient who had vacuum delivery for fetal distress and subsequently had postpartum hemorrhage due to previous caesarean uterine scar rupture and multiple vaginal lacerations. The severe bleeding persisted despite total abdominal hysterectomy, pelvic embolization and vaginal gauze packing, but was finally controlled by a Bakri balloon tamponade inserted into the vagina. The patient suffered from severe stress incontinence after delivery. The possible use of balloon tamponade in vaginal lacerations and the different types of vaginal balloons that are available in the market for this purpose are reviewed. The possible causes leading to stress incontinence is reported to alert the obstetrician that such management is not free of complications.

CONCLUSION

The use of Bakri balloon can help to control bleeding in severe vaginal lacerations that are unresponsive to traditional vaginal gauze packing. Further studies are needed to evaluate the risks of stress incontinence as a possible complication of vaginal balloon tamponade.

A local risk score model for venous thromboembolism prophylaxis for caesarean section in Chinese women and comparison with international guidelines

OBJECTIVE

Recommendations for venous thromboembolism (VTE) prophylaxis from authoritative guidelines for women undergoing caesarean delivery differed significantly and may not be applicable to Chinese populations. We aim to formulate a local risk model for VTE prophylaxis for caesarean section women.

MATERIAL AND METHODS

A local risk score model based on demographic, obstetric and medical parameters was used to assess the risk of VTE in women undergoing caesarean delivery from May 2017 to April 2018 in a regional obstetric unit. Women with increased risk (VTE Score ≥ 2) are given mechanical prophylaxis with pneumatic cuff and those with high risk (VTE Score ≥ 3) are additionally prescribed low molecular weight heparin (LMWH) as pharmacological prophylaxis in the early postpartum period. The risk scores obtained by applying other major guidelines were then compared.

RESULTS

Of 859 patients were included for analysis, overweight (15.3%), advanced maternal age (9.7%), multiple pregnancy (5.1%), obesity (4.7%), and primary postpartum haemorrhage (4.1%) were the most common risk factors. Overall, 109 (12.7%) patients required mechanical prophylaxis and 28 (3.3%) patients required additional pharmacological prophylaxis. No patient had postpartum VTE events nor serious haemorrhage after receiving LMWH prophylaxis. In contrast, applying the Royal College of Obstetricians and Gynaecologists guidelines to our cohort, 649 (75.6%) patients would receive LMWH after caesarean section, compared with no patients under the American College of Obstetrics and Gynaecology guidelines.

CONCLUSIONS

Our local risk score model avoided the need for large proportions of women to be subjected to pharmacological prophylaxis, and appeared safe and practical.

Risk factors for severe postpartum haemorrhage during caesarean section for placenta praevia

The objective of this study was to evaluate the value of clinical and ultrasound risk factors in predicting severe postpartum haemorrhage (PPH) (≥1.5 L) in pregnancies undergoing caesarean section for placenta praevia. This cohort consists of all cases of placenta praevia undergoing caesarean delivery over a period of 5 years in a service unit. Patients and their delivery data were retrieved from an obstetric database. Ultrasound features were prospectively recorded before caesarean section. The incidence of caesarean section for placenta praevia was 0.98% (n = 215). Of these, 12.1% (n = 26) had severe PPH. A logistic regression model showed that major praevia, antepartum haemorrhage before delivery and anterior placenta remained significant factors associated with severe PPH. The sensitivity/specificity and positive/negative predictive value of the model are 96.2%, 59.8%, 24.8% and 99.1%, respectively. Our model had high sensitivity and negative predictive value for severe PPH during caesarean section for placenta praevia.Impact statementWhat is already known on this subject? Placenta praevia is known to be one of the leading causes of severe PPH. Many risk factors have been associated with severe bleeding during caesarean section for placenta praevia. However, the importance of individual factors in predicting pregnancy outcome remains controversial.What the results of this study add? Our model includes only three simple parameters, namely the presence of significant antepartum haemorrhage (APH) from the history, and anterior or posterior placenta and major or minor praevia from ultrasound findings, but could predict up to 96.2% of all severe PPH. More importantly, the absence of APH, a posterior minor praevia, was associated with a negative predictive value of 99.1% of severe PPH, implying that such cases could be treated as 'normal' low risk caesarean sections.What the implications are of these findings for clinical practice and/or further research? This simple model would allow differential pre-operative counselling of patients on risks and complications, planning and preparation of operation, allocation of staff as well as in contingency measures to be taken during operation. The establishment of a differential protocol for placenta praevia based on these simple risks factors and a prospective trial of such a protocol is suggested.

Pathogens in preterm prelabour rupture of membranes and erythromycin for antibiotic prophylaxis: a retrospective analysis

INTRODUCTION

Many authoritative guidelines recommend prescribing erythromycin as antibiotic prophylaxis in patients with preterm prelabour rupture of membranes (PPROM). This study evaluated the spectrum of pathogens in PPROM and assessed the effectiveness of erythromycin prophylaxis.

METHODS

This retrospective study enrolled pregnant patients who were diagnosed with PPROM and who delivered at ≥24 weeks of gestation in an obstetric unit from 2013 to 2017. Pathogens isolated from maternal, placental, and neonatal specimens were analysed; their sensitivity profiles to various antibiotics were recorded. Neonatal outcomes were also evaluated.

RESULTS

The overall incidence of PPROM was 2.63%. Gram-positive bacteria were cultured in 18.4% of PPROM patients (most frequent: Group B Streptococcus [GBS; 14.6%]); Gram-negative bacteria were cultured in 12.8% of PPROM patients (most frequent: Escherichia coli [8.0%]). Both Gram-positive and Gram-negative bacteria were significantly associated with early-onset neonatal sepsis (P=0.036 and P=0.001). In analyses stratified by bacterial species, E coli was significantly associated with early-onset neonatal sepsis (P=0.004), whereas GBS was not (P=0.39). Gram-positive bacteria had high rates of resistance to common antibiotics: 42.2% of GBS and 50.0% of Enterococcus and other Streptococcus bacteria were resistant to erythromycin. Escherichia coli had high rates of resistance to ampicillin (70.3%) and gentamicin (33.3%); rates of resistance to co-amoxiclav (3.6%) and intravenous cefuroxime (14.0%) were low.

CONCLUSION

Gram-positive and Gram-negative bacteria were found in 29.1% of PPROM patients. Administration of erythromycin alone was insufficient to control these bacteria in 67.7% of patients with positive cultures.

Prevalence of chromosomal abnormalities and 22q11.2 deletion in conotruncal and non-conotruncal antenatally diagnosed congenital heart diseases in a Chinese population

INTRODUCTION

The aim of the present study was to calculate the prevalence of chromosomal abnormalities among antenatally diagnosed congenital heart diseases (CHDs), and the prevalence of 22q11.2 deletion in those with conotruncal CHDs versus isolated non-conotruncal CHDs.

METHODS

All patients with antenatal ultrasound finding of fetal CHDs in two obstetric units in a 5-year period were retrospectively reviewed. Detected CHDs were classified as conotruncal if the malformation involved either the aortic outflow tract or the pulmonary outflow tract; otherwise they were classified as non-conotruncal. Karyotyping, fluorescence in situ hybridisation for 22q11.2 deletion (22q11FISH), and array comparative genomic hybridisation (aCGH) results were retrieved from patient medical records. The primary outcome was prevalence of chromosomal abnormalities in CHDs. The secondary outcomes were prevalence of 22q11.2 deletion and its prevalence in conotruncal versus non-conotruncal CHDs.

RESULTS

A total of 254 Chinese patients were diagnosed to have fetal CHDs. In all, 50 (19.7%) were found to have chromosomal abnormalities with seven (2.8%) patients having 22q11.2 deletion, of whom all seven had conotruncal CHDs and none had non-conotruncal CHDs (P<0.05). Conventional karyotyping detected 35 (70%) cases of the chromosomal abnormalities. The 22q11FISH detected three cases of 22q11.2 deletion; aCGH was performed to detect four cases of 22q11.2 deletion and eight other cases of copy number variations.

CONCLUSION

Our results suggest that invasive testing for karyotyping is recommended for fetal CHDs. Although the prevalence of 22q11.2 deletion was low, testing for 22q11.2 deletion should be offered for conotruncal CHDs.

Menstrual and reproductive outcomes after use of balloon tamponade for severe postpartum hemorrhage

BACKGROUND

The use of intrauterine balloon tamponade to manage postpartum hemorrhage is increasing. However, there is lack of studies on the menstrual and reproductive outcomes after such treatment. The purpose of this study is to explore the menstrual and reproductive outcomes for patients who had been managed by intrauterine balloon tamponade for severe postpartum hemorrhage in her index pregnancy.

METHODS

All patients who had delivered in United Christian Hospital from January 2011 to June 2016 with severe postpartum hemorrhage (PPH) (blood loss> = 1 L) were identified by the labour ward delivery registry and a comprehensive obstetric database. Patients who had intrauterine balloon tamponade inserted were compared with those managed solely by uterotonic agents as controls. Patients who had hysterectomy or additional procedures performed, such as compression sutures or uterine artery embolization were excluded from both groups. A questionnaire on menses, fertility and reproductive outcomes was mailed to both groups of patients. Those that had not replied within 4 weeks would receive a telephone survey.

RESULTS

A total of 39 patients in the balloon tamponade group and 161 patients in the control group were recruited, which represented 87.0% of all eligible patients within the study period. The median follow up period was 45 months. All patients in the balloon tamponade group had return of menses after delivery. The majority of the patients (87.2%) in the balloon tamponade group had normal menstrual patterns in the 12 months after the index delivery as well as in the most recent 12 months. After excluding the patients with contraception, the subsequent pregnancy rate was 42.9% (9/21) in the balloon tamponade group compared to 45.9% (28/61) in the control group (p = 0.81). Among the 9 subsequent pregnancies in the balloon tamponade group, there were two miscarriages, one scar pregnancy, one induced abortion, while the remaining five were normal pregnancies with full term deliveries without intrauterine growth restriction. The majority of patients replied that they were satisfied with using Bakri balloon for PPH management in their index pregnancy.

CONCLUSIONS

Intrauterine balloon tamponade for the management of severe PPH appeared to pose little adverse effects on subsequent menstrual and reproductive function.

Prognostic factors for the use of intrauterine balloon tamponade in the management of severe postpartum hemorrhage

OBJECTIVE

To identify prognostic factors associated with successful management of severe postpartum hemorrhage (PPH) using intrauterine balloon tamponade (IUBT).

METHODS

Retrospective review of all cases of severe PPH with blood loss greater than 1 L in a tertiary unit in Hong Kong from July 1, 2012, to June 30, 2017. Records of patients who had undergone IUBT insertion were reviewed. Univariate analysis and logistic regression models were used to identify prognostic factors for successful management with IUBT.

RESULTS

Of 22 860 deliveries during the study period, severe PPH occurred in 1.4% (n=311), and IUBT was attempted in 26.0% (n=81) of these patients. IUBT alone was successful in arresting hemorrhage in 72.8% (n=59), and the overall rate for avoiding hysterectomy was 86.4% (n=70). Presence of coagulopathy (P=0.048) and placenta accreta (P=0.048) were the adverse prognostic factors associated with higher failure rates. Less blood loss (≤1400 mL) at the time of insertion of IUBT and a positive tamponade test (≤50 mL of blood drained from the uterus within the first 30 minutes after insertion of IUBT) were good predictors for success of IUBT.

CONCLUSION

The presence of adverse prognostic factors should prompt early resort to other treatment modalities or hysterectomy as a salvage procedure.

Intraluminal pressure of uterine balloon tamponade in the management of severe post-partum hemorrhage

AIM

Intrauterine balloon tamponade has been increasingly used for the management of post-partum hemorrhage (PPH) in recent years. However, data on the precise mechanisms and pressure required for the balloon tamponade are scanty in the literature. This study aims to review the intraluminal pressure (ILP) generated by the Bakri intrauterine balloon that is necessary to produce a 'positive tamponade test' during severe PPH.

METHODS

This was a prospective cohort study. The ILP of the Bakri balloon was measured using a manometer after a positive tamponade test was clinically achieved during severe PPH (blood loss >1 L). The patient's blood pressure was recorded, and ultrasound scan was performed to verify the position of the balloon and the presence of forward flow in the uterine arteries. The main outcome measure is the ILP of the Bakri balloon required to achieve a positive tamponade test.

RESULTS

Twenty patients were included for final analysis. The net ILP measured ranged from 67 to 92 mmHg, and this pressure was lower than the concurrent systolic pressure in all cases. Color Doppler confirmed positive forward flow in the uterine vessels in all cases. There were no differences in the pressure measured with the balloon position, and there was no relationship between the volumes of saline infused and the net pressure.

CONCLUSION

A positive tamponade test in an intrauterine balloon is probably achieved by local compression pressure exerted on the vasculature of the placental bed rather than by generating an ILP exceeding systemic blood pressure or by occlusion of flow to the uterine arteries.

Trends in conservative procedures and peripartum hysterectomy rates in severe postpartum haemorrhage

OBJECTIVE

The objective of this study is to explore whether increase in use of second-line conservative surgical procedures will alter the rate of peripartum hysterectomies in management of severe postpartum haemorrhage (PPH).

METHODS

This is a retrospective cohort. All pregnant patients with gestation > = 28 weeks with severe PPH (> = 1.5 L) within 72 h of delivery from year 2000 to 2015 (16-year period) in an obstetric training unit was recruited. Basic patient anthropometric characteristics and the main causes for PPH were calculated. The incidence of any second-line conservative surgical procedures and peripartum hysterectomies were evaluated. The total number of patients in each category was then stratified into four 4 years-intervals (4 quadrennium) to compare trends.

RESULTS

The incidence of severe PPH gradually increased over the study period (lowest 0.21% in 2002 to 0.76% in 2015) (p < .001). There is an obvious increasing trend in the overall use of second-line surgical procedures from nil to 82% (p < .001), with balloon tamponade constituting up to 48%. The incidence of successful second-line procedures increased gradually from 72.2% in the second quadrennium to 89% in the fourth quadrennium. The total peripartum hysterectomy rate among cases of severe PPH could be seen to drop from 40.2% in the first to 10.9% in the fourth quadrennium (p = .04).

CONCLUSIONS

Despite the increasing trends in PPH, the increasing utilisation of second-line conservative surgical procedures in severe PPH should be able to reduce the need for peripartum hysterectomy.

Secular trends in caesarean section rates over 20 years in a regional obstetric unit in Hong Kong

INTRODUCTION

Although caesarean section rates have been increasing over the years in both public and private sectors in Hong Kong, there has been a paucity of formal surveys on local trends in such rates. This study aimed to examine the trends in caesarean section rates over a 20-year period at a public regional obstetric unit in Hong Kong using the Robson's Ten-group Classification System.

METHODS

All deliveries in a single obstetric unit during a 20-year period (1995-2014) were classified into 10 subgroups according to the Robson's classification. The annual caesarean section rate for each subgroup was calculated and then stratified into 5-year intervals to analyse any significant trends.

RESULTS

The caesarean section rates in a total of 86 262 births with complete data were analysed. The overall caesarean section rate increased modestly from 15.4% to 24.6% during the study period. There was an obvious increasing trend for caesarean section in those with previous caesarean section (Robson's category 5), breech presentation at delivery (category 6 and 7), multiple pregnancy (category 8), and preterm labour (category 10). A gradual fall in caesarean section rate from 14.4% to 10.8% was seen in primiparous women with term spontaneous labour (category 1). Statistically significant differences (P<0.001) in these trends were confirmed when the data were stratified into 5-year intervals for comparison.

CONCLUSION

The rising caesarean section rate may be associated with clinical management policies that allow women with relative risk factors (such as breech, previous caesarean section, or multiple pregnancy) to opt for caesarean section. This rise was counterbalanced by a decrease in primary caesarean section rate in primiparous women with spontaneous labour. The trend for caesarean section was more in line with patient expectations rather than evidence-based practice.

The predicting factors and outcomes of caesarean section of the second twin

The aim of this study was to review the indications for caesarean delivery of second twins after vaginal delivery of a first twin (combined delivery) and the associated foetal outcomes of the second twin. Possible factors that could be employed to predict combined delivery were explored. This was a retrospective review of all twin pregnancies delivered in a tertiary maternity unit between 2000 and 2013. All twins (> =24 week gestation) with vaginal delivery of the first twin were reviewed. Of a total of 1039 pairs of twins, 441 pairs had vaginal delivery of the first twin, of which 47 (10.7%) needed combined delivery. Presentation of the second twin was found to be significantly associated with combined delivery (p < .001). The odds ratio for combined delivery for breech second twin was 2.4 compared with vertex second twins while the odds ratio for transverse lie second twin was 182.8. Second twins who were delivered by combined delivery had a higher incidence of 5 min Apgar score <7. The extremely high odds ratio for combined delivery for second twins in transverse lie would probably indicate that attempts at vaginal delivery of these vertex/transverse twin pregnancies would not be worthwhile. Impact statement It remains controversial in the literature whether non-vertex second twins are associated with a higher risk for combined delivery as compared to vertex second twins. Almost all previous studies have analysed the non-vertex second twins as a whole group rather than separating them into breech presentation and transverse lie. There is only one study analysing breech presentation and transverse lie of second twin separately but it has recruited only 14 patients. To our knowledge, the cohort is the largest available dataset comparing the odds ratio for combined delivery of breech and transverse lie of the second twin separately. We found that transverse lie of the second twin have extremely high rates of combined delivery with an odds ratio 182.8 and this may be ascribed to the lack of attempts to perform internal podalic version. Combined delivery is associated with higher maternal and neonatal morbidities. With such a high risk of transverse lie second twin in having combined delivery, it appears reasonable to advise women with vertex/transverse twins not to attempt vaginal delivery unless there are obstetricians who have experience in performing internal podalic version at the time of delivery. This is useful for patient counselling regarding the decision of the mode of delivery.

Nitric Oxide-cGMP-PKG Pathway Acts on Orai1 to Inhibit the Hypertrophy of Human Embryonic Stem Cell-Derived Cardiomyocytes

Cardiac hypertrophy is an abnormal enlargement of heart muscle. It frequently results in congestive heart failure, which is a leading cause of human death. Previous studies demonstrated that the nitric oxide (NO), cyclic GMP (cGMP), and protein kinase G (PKG) signaling pathway can inhibit cardiac hypertrophy and thus improve cardiac function. However, the underlying mechanisms are not fully understood. Here, based on the human embryonic stem cell-derived cardiomyocyte (hESC-CM) model system, we showed that Orai1, the pore-forming subunit of store-operated Ca(2+) entry (SOCE), is the downstream effector of PKG. Treatment of hESC-CMs with an α-adrenoceptor agonist phenylephrine (PE) caused a marked hypertrophy, which was accompanied by an upregulation of Orai1. Moreover, suppression of Orai1 expression/activity using Orai1-siRNAs or a dominant-negative construct Orai1(G98A) inhibited the hypertrophy, suggesting that Orai1-mediated SOCE is indispensable for the PE-induced hypertrophy of hESC-CMs. In addition, the hypertrophy was inhibited by NO and cGMP via activating PKG. Importantly, substitution of Ala for Ser(34) in Orai1 abolished the antihypertrophic effects of NO, cGMP, and PKG. Furthermore, PKG could directly phosphorylate Orai1 at Ser(34) and thus prevent Orai1-mediated SOCE. Together, we conclude that NO, cGMP, and PKG inhibit the hypertrophy of hESC-CMs via PKG-mediated phosphorylation on Orai1-Ser-34. These results provide novel mechanistic insights into the action of cGMP-PKG-related antihypertrophic agents, such as NO donors and sildenafil.

Impact of nuchal cord on fetal outcomes, mode of delivery, and management: a questionnaire survey of pregnant women

OBJECTIVES

To explore pregnant women's views on the impact of nuchal cord on fetal outcomes, mode of delivery, and management.

DESIGN

Questionnaire survey.

SETTING

Antenatal clinic of two regional hospitals in Hong Kong.

PARTICIPANTS

A questionnaire survey of all pregnant women at their first visit to the antenatal clinic of United Christian Hospital and Tseung Kwan O Hospital in Hong Kong was conducted between August and October 2012.

RESULTS

Most participants (71.8%) were worried about nuchal cord, and 78.3% and 87.7% of them thought that nuchal cord could cause intrauterine death and fetal death during labour, respectively. Approximately 87.5% of participants thought that nuchal cord would reduce the chance of successful vaginal delivery and 56.4% thought that it would increase the chance of assisted vaginal delivery. Most (94.1%) participants thought that it was necessary to have an ultrasound scan at term to detect nuchal cord. In addition, 68.8% thought that it was necessary to deliver the fetus early and 72.8% thought that caesarean section must be performed in the presence of nuchal cord. Participants born in Mainland China were significantly more worried about the presence of nuchal cord than those born in Hong Kong. However, there was no difference between participants with different levels of education.

CONCLUSION

Most participants were worried about the presence of nuchal cord. Many thought that nuchal cord would lead to adverse fetal outcomes, affect the mode of delivery, and require special management. These misconceptions should be addressed and proper education of women is needed.

The prevalence of microalbuminuria among patients with type II diabetes mellitus in a primary care setting: cross-sectional study

OBJECTIVES

To determine the prevalence of microalbuminuria among patients with type II diabetes mellitus in a primary care setting, and to study the association between various risk factors and the presence of microalbuminuria.

DESIGN

Cross-sectional community-based study.

SETTING

Four primary care clinics, Hong Kong.

PATIENTS

All patients with type II diabetes mellitus who regularly attended the clinics between May 2002 and March 2003.

MAIN OUTCOME MEASURES

Patients' demographic data, the proportion with microalbuminuria (measured using a spot urine test), and the association between this condition and risk factors for diabetic nephropathy (via correlation and multivariable logistic regression analysis).

RESULTS

The mean age of the 1161 patients in the sample population was 58.0 years. The mean duration of diabetes mellitus was 5.7 years, and the mean level of glycated haemoglobin was 7.4%. A total of 13.4% of the patients had microalbuminuria. Having the condition was significantly associated with advanced age, female sex, poor glycaemic control, and coexisting hypertension in both correlation and regression analyses. No significant association with ever smoking was found.

CONCLUSION

Early screening for incipient diabetic nephropathy and aggressive management of modifiable risk factors in a primary care setting may be important in optimising the renal outcome of patients with type II diabetes mellitus.

Oxidative DNA damage in human peripheral leukocytes induced by massive aerobic exercise

Reactive oxygen species produced during vigorous exercise may permeate into cell nuclei and induce oxidative DNA damage, but the supporting evidence is still lacking. By using a 42 km marathon race as a model of massive aerobic exercise, we demonstrated a significant degree of unrepaired DNA base oxidation in peripheral immunocompetent cells, despite a concurrent increase in the urinary excretion of 8-hydroxy-2'-deoxyguanosine. Single cell gel electrophoresis with the incorporation of lesion-specific endonucleases further revealed that oxidized pyrimidines (endonuclease III-sensitive sites) contributed to most of the postexercise nucleotide oxidation. The oxidative DNA damage correlated significantly with plasma levels of creatinine kinase and lipid peroxidation metabolites, and lasted for more than 1 week following the race. This phenomenon may be one of the mechanisms behind the immune dysfunctions after exhaustive exercise.

Leukocyte mitochondria depolarization and apoptosis in advanced heart failure: clinical correlations and effect of therapy

OBJECTIVES

The purpose of this study was to examine the changes in leukocyte mitochondrial transmembrane potential (MTP) and its association with apoptosis in congestive heart failure (CHF).

BACKGROUND

Congestive heart failure is a heterogeneous syndrome with multiple hemodynamic, neuroendocrine and immune abnormalities. Although edematous CHF may be associated with endotoxemia and increased cytokine production, peripheral blood leukocyte functions in advanced CHF remain unclear.

METHODS

Thirty patients with acute decompensated CHF (mean age [+/- SEM] 74.9 +/- 3.1 years) and 20 healthy controls underwent determination of MTP, intracellular oxidants and apoptosis in three subsets of peripheral blood leukocytes. The measurements were repeated after the time of recompensation.

RESULTS

Patients with acute CHF showed marked MTP reduction and increased intracellular oxidant formation in three subsets of leukocytes upon entry into the study. These changes were more prominent in patients with peripheral edema. The decline in MTP was correlated with the severity of the peripheral edema and plasma concentration of cortisol, nitrogen metabolites and tumor necrosis factor-alpha (p < 0.01). After clinical stabilization, MTP gradually recovered. Leukocytes underwent increased propensity of apoptosis one week after the time of recompensation.

CONCLUSIONS

The mitochondrial depolarization and apoptosis of leukocytes in decompensated heart failure suggest that CHF is associated with severity-dependent impairments in leukocyte function. Accentuated hormonal and cytokine abnormalities and increased circulating oxidants may contribute to these changes. Early and aggressive management of advanced heart failure is helpful in the recovery of these immune abnormalities.

Age-related changes in the mitochondrial depolarization induced by oxidative injury in human peripheral blood leukocytes

Aging is associated with impaired immunity and reduced host defenses. Mitochondrial bioenergetic dysfunctions and reduced antioxidative ability of immunocompetent cells may contribute to this phenomenon. In this study, 60 healthy volunteers of different age groups donated their blood after overnight fasting. Leukocytes were subjected to oxidative injuries by exposure to t-butylhydroperoxide, and were labeled with fluorochromes for measuring mitochondria transmembrane potential (delta psi m), membrane peroxidation and mitochondrial oxidant formation. delta psi m declined after t-butylhydroperoxide exposure, and the change was more prominent in leukocytes from older individuals. Cyclosporin A partly restored delta psi m, implying the contributing role of mitochondrial permeability transition pores. The mitochondrial depolarization was accompanied by increased oxidant formation and oxidation of pyridine nucleotides, which were more prominent in older subjects. The results support the view that the bioenergetic functions of mitochondria are more susceptible to oxidative injury in aged individuals. The decreased ability of leukocytes to resist oxidative stress may contribute to immunosenescence in humans.

Ultrasound-guided cannulation of the internal jugular vein for dialysis vascular access in uremic patients

BACKGROUND

A reliable temporary vascular access is always required for hemodialysis when a permanent vascular access is not available. However, techniques for creating temporary vascular accesses remain imperfect. This study utilized the 'SiteRite' ultrasound device to improve both success and complication rates of jugular venous cannulation for temporary access.

METHODS

This prospective, comparative study recruited 104 uremic patients receiving ultrasound-guided and 86 patients undergoing landmark-guided percutaneous internal jugular venous cannulation of dual-lumen dialysis catheters. Success rate, number of puncture attempts, access time, and the complication rate of the ultrasound technique, in comparison with the landmark-guided technique, were studied.

RESULTS

The ultrasound-guided cannulation was superior to the external landmark-guided cannulation in overall success rate (99.0 vs. 86.0%, p < 0.01), success rate of the first puncture attempt (80.8 vs. 34.9%, p < 0.01), average puncture (access) times (15.8 vs. 43.7 s, p < 0.01), puncture trials (1.39 vs. 2.58, p < 0.01), and traumatic complication rate (1.9 vs. 1 1.6%, p = 0.015). The incidence of infective complications for the ultrasound group was not different from that of the landmark-guided groups (2.9 vs. 2.3%, p = 0.589).

CONCLUSION

The ultrasound-guided technique offers both safety and convenience in inserting jugular venous dialysis catheters. It represents a valuable technique in creating temporary dialysis hemoaccesses.

The relationship of late potentials to assessment of heart rate variability in post-infarction patients

In order to investigate the relationship of late potential (LP) to assessment of heart rate variability (HRV) after acute myocardial infarction (AMI), we studied 101 Chinese patients with AMI (10+/-2.4 days) in Taiwan by collecting 24-h ECG from a Holter tape recorder and signal-averaged ECG from a high-resolution ECG cart. Of the 101 patients, 36 patients had LP (LP group) and 65 patients did not (NLP group). The mean heart rate was significantly lower in the LP group than in the NLP group (P<0.05). The LP group had a significantly increased high-frequency (HF) spectral component of HRV compared with the NLP group (P<0.005), but their low-frequency (LF) to HF ratio (LF/HF) was lower (P<0.05). Analysis of the circadian variation of HRV revealed significant difference of morning SDRR (standard deviation of normal RR intervals) compared with noon SDRR (P<0.05 in the LP group, P<0.005 in the NLP group) and evening SDRR (P<0.05 in the LP group, P<0.005 in the NLP group). In the NLP group, morning HF (normalized unit, nu) was 0.258+/-0.098 compared with noon HF (nu) of 0.219+/-0.83 (P<0.05) and evening HF (nu) of 0. 225+/-0.085 (P<0.05). Nine patients died during follow-up from cardiac causes, three (8.3%) in the LP group and six (9.2%) in the NLP group. In post-MI patients, there was higher vagal tone in patients with late potentials compared to those without late potentials. NLP patients had more circadian change in vagal tone compared with LP patients.

Magnolol attenuates peroxidative damage and improves survival of rats with sepsis

Reactive oxygen species and peroxidative damage are implicated in the pathophysiology of sepsis. Magnolol is a compound extracted from the Chinese medicinal herb Magnolia officinalis and has multiple pharmacological effects, notably antioxidant functions. To determine whether magnolol can modulate the course of sepsis, survival rate and biochemical parameters were analyzed in rats with sepsis with various treatment protocols. Magnolol at doses ranging from 10(-9) g/kg to 10(-5) g/kg was administered either before or after induction of sepsis by cecal ligation and puncture. Magnolol did not modulate the course of sepsis induced by two cecal punctures. When one cecal puncture was performed, a moderately evolving type of sepsis was induced, and the survival rate of affected rats was significantly improved by pretreatment with 10(-7) g/kg magnolol. The beneficial effect was partially retained if magnolol was administered 6 hours after onset of sepsis when a higher dose (10(-5) g/kg) was used. The intensity of lipid peroxidation in plasma, liver, and lung of septic rats was also attenuated in a treatment-dependent manner. Magnolol at this dose range exerted these beneficial effects probably through its antioxidant efficacy. These significant results may suggest magnolol as a candidate agent for the treatment of sepsis.

Factors affecting gentamicin pharmacokinetics in septic patients

BACKGROUND

This prospective, comparative study was designed to estimate the volume of distribution (Vd) and elimination rate constant (K(e)) of gentamicin and to determine the clinical factors affecting the pharmacokinetics of gentamicin in different stages of sepsis.

METHOD

Seventy-seven critically ill patients treated with gentamicin for gram-negative sepsis were included. These septic patients were divided into hyperdynamic septic and hypodynamic septic groups according to cardiac index. Twenty-seven patients who received postoperative prophylactic gentamicin were recruited as controls.

RESULTS

Fifty-two patients in the hyperdynamic septic group had a significantly larger Vd than those in the hypodynamic septic and control groups. The Vd was correlated significantly with both Acute Physiological Score (APS) (r=0.340, P<0.01) and cardiac index (r=0.394, P<0.01). The K(e) of gentamicin correlated significantly with both blood urea nitrogen (BUN) (r= 0.565, P<0.01) and serum creatinine level (r=0.563, P<0.01).

CONCLUSION

The increased Vd in the septic patients was related to the severity of illness and magnitude of cardiac output. The K(e) of gentamicin was correlated with the serum creatinine level.

Acute and chronic phase platelet aggregability studies in Chinese patients after implantation of a permanent transvenous pacemaker

It has been suggested that the incidence of thromboembolic events always increases in patients after insertion of a transvenous pacemaker. Blood samples from twenty consecutive patients (fifteen males and five females) before and after pacemaker implantation was retained for platelet aggregability studies which were analyzed separately with ADP, collagen, epinephrine and arachidonic acid. The maximal amplitude of platelet aggregatory curve was detected by an aggregometer. The samples collected the day before pacemaker implantation (day 0) were used as self-control. Day 1 and day 3 after pacemaker implantation were defined as the acute phase, while day 30 was defined as the chronic phase. The maximal amplitude of platelet aggregatory curve was observed to be lowest on day 1 and then return to normal on day 3 and day 30. The results of platelet aggregability, however, showed no significant difference (P>0.05) between self-control and post-implantation samples. In conclusion, there was no significant change in platelet aggregability for either acute or chronic phases after pacemaker implantation. Antiplatelet medications may not be necessary for the prevention of thromboembolic events after the implantation of a pacemaker.

Single-lead VDD pacemaker implantation via persistent left superior vena cava: an improved technique and a new modality

Persistent left superior vena cava (PLSVC), which occurs in approximately 0.5% of the general population, may complicate pacemaker implantation by making lead insertion into the right ventricle more difficult and increasing lead instability when the transvenous approach is attempted. We describe our experience with four PLSVC patients with pacemakers. We developed an open J-loop technique in which the stylet tip is directed toward the orifice of the tricuspid valve anteroinferiorly. The lead was implanted into the right ventricular apex without difficulty. Three of our patients had high-degree atrioventricular block and received VVI pacemakers with the new technique. One patient with complete atrioventricular block received a single-lead VDD pacemaker by means of the same technique, with the paired electrodes positioned in the lower right atrium. Excellent results were obtained on exercise tolerance testing, 24-hour Holter monitoring, and echocardiographically determined systolic and diastolic function. This improved technique can simplify pacemaker implantation in patients with PLSVC. The VDD device is a new way to maintain systolic and diastolic function and is an appropriate option in patients with high-degree atrioventricular block and PLSVC who require pacemaker implantation.

Oxidative stress: an important phenomenon with pathogenetic significance in the progression of acute pancreatitis

BACKGROUND

Reactive oxygen species and related oxidative damage have been implicated in the initiation of acute pancreatitis. Changes in these parameters during disease progression merit further investigation.

AIMS

To evaluate changes and the clinical relevance of superoxide radicals, endogenous antioxidants, and lipid peroxidation during the course of acute pancreatitis.

PATIENTS AND METHODS

Superoxide radicals (measured as lucigenin amplified chemiluminescence), ascorbic acid, dehydroascorbic acid, alpha tocopherol, and lipid peroxidation (measured as thiobarbiturate reactive substances) were analysed in blood samples from 56 healthy subjects, 30 patients with mild acute pancreatitis, and 23 patients with severe acute pancreatitis. The association with grades of disease severity was analysed. Measurements were repeated one and two weeks after onset of pancreatitis.

RESULTS

In the blood from patients with acute pancreatitis, there were increased levels of the superoxide radical as well as lipid peroxides. There was notable depletion of ascorbic acid and an increased fraction of dehydroascorbic acid. Changes in alpha tocopherol were not great except in one case with poor prognosis. Differences between severe and mild acute pancreatitis were significant (p < 0.01). Variable but significant correlations with disease severity scores were found for most of these markers. The normalisation of these indexes postdated clinical recovery one or two weeks after onset of disease.

CONCLUSIONS

Heightened oxidative stress appears early in the course of acute pancreatitis and lasts longer than the clinical manifestations. The dependence of disease severity on the imbalance between oxidants and natural defences suggests that oxidative stress may have a pivotal role in the progression of pancreatitis and may provide a target for treatment.

Esophageal PP intervals for analysis of short-term heart rate variability in patients with atrioventricular block before and after insertion of a temporary ventricular inhibited pacemaker

Heart rate variability (HRV) analysis is a useful method for assessment of the activities of autonomic nervous system. The RR intervals in ECG is measured for this purpose. However, RR intervals are not suitable for HRV analysis in atrioventricular block (AV) block patients with ventricular inhibited (VVI) pacemaker, as the intervals will be fixed by the ventricular pacemaker. Thus we used an esophageal lead to detect PP intervals for analysis of HRV. The aim of this study was to evaluate the short-term HRV by using an esophageal electrode to detect the atrial signal and PP intervals in AV block patients. Fifteen AV block patients before and after temporary VVI pacemaker and 15 subjects with normal AV conduction (control group) were enrolled in this study. The atrial signals from esophageal lead, ECG and intraatrial lead were recorded. The duration was 10 min. We compared correlation coefficient of PP intervals from different leads in AV block patients and the control group. We also compared the PP interval's variability parameters between the control group and AV block patients, before and after insertion of a temporary ventricular inhibited pacemaker. The esophageal PP intervals were excellently correlated with intraatrial AA intervals (r=0.98+/-0.01). The HRV using esophageal PP intervals with time domain demonstrated a significant decrease in patients with AV block (standard deviation of all PP intervals (SDNN) (s)=0.022+/-0.014; percentage difference between adjacent PP intervals that are greater than 50 ms (pNN-50) (%)=0.052+/-0.038; square root of the mean of squares of differences between duration of neighboring PP intervals (r-MSDD) (s)=0.322+/-0.082) but this returned to normal after insertion of a temporary ventricular inhibited pacemaker (SDNN (s)=0.035+/-0.009; pNN-50 (%)=2.540+/-1.682; r-MSDD (s)=0.542+/-0.190). However, the ratio of low frequency/high frequency (LF/HF) still increased (LF/HF=4.120+/-1.802). The result of this short-term HRV analysis suggested that withdrawal of vagal tone or increased sympathetic activity in AV block patients compared with the control group. This appearance was normalized after insertion of a temporary VVI pacemaker. however, abnormal sympathovagal balance still remained.

Anatomical variation of the internal jugular vein and its impact on temporary haemodialysis vascular access: an ultrasonographic survey in uraemic patients

BACKGROUND

Creation of a reliable haemoaccess is a critical problem for practicing nephrologists once haemodialysis has been considered. A double-lumen internal jugular-vein catheter is favoured in most cases requiring temporary haemoaccess. However, numerous complications, even lethal ones, may occur with the cannulating procedure. Using ultrasound, we attempted to describe the occult anatomical variations of vessels which may be responsible for complications.

METHODS

A 'SiteRite' ultrasonographic device was used to inspect the anatomical structure of the internal jugular veins (IJV) in 104 consecutive uraemic patients undergoing creation of internal jugular vein temporary angioaccess. Images of the vessels and demographic data of patients were recorded and analysed.

RESULTS

Anatomical variations of the right and left IJVs were found in 19 (18.3%) and 17 (16.4%) uraemic patients respectively. Unilateral IJV variations were found in 18 patients (17.3%) and bilateral variations were discovered in nine patients (8.7%). A total of 27 patients (26.0%) had IJV anatomical variations that might contribute to difficulty in external landmark-guided IJV cannulation.

CONCLUSIONS

The external anatomical landmarks for cannulating the IJV are not reliable in about one-quarter of uraemic patients. An ultrasound survey on the IJV anatomy is recommended for selecting proper puncture site and reducing risks of insertion complications for IJV dialysis catheters.

Right ventricular electrode lead implantation via a persistent left superior vena cava. An improved technique

Persistent left superior vena cava occurs in approximately 0.5% of the population. This may complicate pacemaker implantation by making lead insertion difficult and causing lead instability through the left cephalic vein and the subclavian vein approach. We used a wide loop technique in the right atrium and successfully advanced the lead in the right ventricle apex. A persistent left superior vena cava does not preclude successful lead placement.

New stenosis on proximal coronary segment after directional atherectomy. Two case reports

Two patients with new coronary stenotic lesions subsequently developed proximal to the sites accepting directional coronary atherectomy (DCA) are reported. One lesion developed at the left main coronary artery and the other at the proximal segment of the left anterior descending artery. The mechanisms of the development of such new stenotic lesions after DCA were studied and procedure-related mechanical trauma over the proximal segment of the primary lesion may be the possible mechanism for such complication.

Malfunction of an active fixation J-shaped screw-in atrial electrode lead: a case report

Active fixation leads, using active grasping devices, ensure good postoperative lead fixation, long-term performance, and make possible later lead removal on demand. However, these delicate designs have not been without practical difficulties. We present two cases of fixation stylet fracture during helix extension and retraction maneuver respectively with resultant lead inoperability and abandonment. The fixed leads could be removed by torquing the entire lead counterclockwise.

Heart rate variability in patients with atrioventricular block

BACKGROUND

Heart rate variability (HRV) analysis has been an established method for assessment of the activities of autonomic nervous system. Conventionally, the RR intervals from the surface electrocardiogram (ECG) are used for HRV analysis, however, analysis of the RR intervals may not be suitable in patients with atrioventricular (AV) node dysfunction, particularly in patients with certain degree of AV block. We used an esophageal electrode to detect PP intervals for HRV analysis in these patients.

METHODS

Seven AV block patients and 13 subjects with normal AV conduction (control group) were enrolled in this study. The signals from esophageal lead, surface lead and intraatrial lead were recorded. Correlation coefficient of heart beat intervals from different leads was analyzed. Then we compared the HRV parameter recorded by esophageal lead between AV block patients and the control group.

RESULTS

The AA intervals in intraatrial ECG and the PP intervals in surface ECG were poorly correlated (r = 0.489) in the AV block patients. However, intraatrial ECG was correlated well with esophageal ECG (r = 0.968). HRV with time domain decreased significantly in patients with AV block. The standard deviation of NN intervals (SDNN), pNN-50 and r-MSSD in the control group and the AV block patients were 0.035 +/- 0.006 vs. 0.021 +/- 0.016 seconds (p = 0.002), 3.210 +/- 3.120 vs. 0.050 +/- 0.040% (p = 0.027) and 0.577 +/- 0.181 vs. 0.318 +/- 0.084 seconds (p = 0.009), respectively.

CONCLUSIONS

The esophageal lead recording is a non-invasive, easy and safe method to detect HRV of AV block patients whose vagal activity is abnormal.

Sequential hemodynamic changes for large volume paracentesis in post-hepatitic cirrhotic patients with massive ascites

Large volume paracentesis (4.8 to 15.5 liters) was performed in 42 patients with post-hepatitic cirrhosis and massive ascites, not only to derive parameters capable of predicting the development of severe clinical hypotension after large volume paracentesis, but also to determine the optimal time to introduce preventive volume expanders. Systemic hemodynamics were sequentially measured for 72 hours in thirty-two patients. Severe clinical hypotension occurred in 13 (31.0%) patients 4-62 hours from the start of paracentesis. Univariate analysis, with the Mantel-Cox test used to compare Kaplan-Meier curves, and the subsequent multivariate analysis by stepwise Cox regression procedure were utilized to identify two variables, withdrawn ascitic fluid greater than 7.5 liters (p = 0.0121) and the absence of peripheral edema (p = 0.0148), reaching statistical significance to predict the occurrence of severe clinical hypotension. Compared to the baseline value, the cardiac output of patients not developing severe clinical hypotension increased (6.26 +/- 0.66 vs. 6.65 +/- 0.69 liter/min, p < 0.01) one hour from the start of paracentesis and right atrial pressure decreased (11.2 +/- 2.4 vs. 8.7 +/- 2.3 mmHg, p < 0.05). The cardiac output returned to the baseline value at the 9th hour. Based on the results presented herein, we can conclude that severe clinical hypotension occurs in a high percentage of patients with post-hepatitic cirrhosis and massive ascites within 72 hours from the start of large volume paracentesis. At potential risk of this occurring are those patients without peripheral edema and withdrawn ascitic fluid greater than 7.5 liters. Volume expanders should be introduced before 4th hour from the start of large volume paracentesis.

Changes in cardiac autonomic activities in patients with syndrome X. A study of spectral analysis of heart rate variability

The present study was designed to assess cardiac autonomic activities, coronary microvascular function, and their relationship in patients with syndrome X. Control of coronary blood flow is complex, and impaired coronary flow reserve has been attributed as the cause of myocardial ischemia in patients with syndrome X. It is unknown whether cardiac autonomic activities are altered in the presence of coronary microvascular dysfunction in patients with syndrome X. Eighteen patients with syndrome X were studied. Great cardiac vein flow was measured by the thermodilution method and the coronary flow reserve was determined by intravenous dipyridamole (0.56 mg/kg) infusion. Twenty-four-hour ambulatory electrocardiograms were obtained in a drug-free state. Another 14 age- and sex-matched normal subjects served as a control group. The amplitude (in ms) of ultralow (ULF), very-low (VLF), low (LF), and high (HF) frequency bands and total spectra of heart rate variability were measured for twenty-four-hour and every four-hour interval of the day.