Major Intraoperative Complications During Minimally Invasive Esophagectomy

BACKGROUND

Studies have shown minimally invasive esophagectomy (MIE) to be a feasible surgical technique in treating esophageal carcinoma. Postoperative complications have been extensively reviewed, but literature focusing on intraoperative complications is limited. The main objective of this study was to report major intraoperative complications and 90-day mortality during MIE for cancer.

METHODS

Data were collected retrospectively from 10 European esophageal surgery centers. All intention-to-treat, minimally invasive laparoscopic/thoracoscopic esophagectomies with gastric conduit reconstruction for esophageal and GE junction cancers operated on between 2003 and 2019 were reviewed. Major intraoperative complications were defined as loss of conduit, erroneous transection of vascular structures, significant injury to other organs including bowel, heart, liver or lung, splenectomy, or other major complications including intubation injuries, arrhythmia, pulmonary embolism, and myocardial infarction.

RESULTS

Amongst 2862 MIE cases we identified 98 patients with 101 intraoperative complications. Vascular injuries were the most prevalent, 41 during laparoscopy and 19 during thoracoscopy, with injuries to 18 different vessels. There were 24 splenic vascular or capsular injuries, 11 requiring splenectomies. Four losses of conduit due to gastroepiploic artery injury and six bowel injuries were reported. Eight tracheobronchial lesions needed repair, and 11 patients had significant lung parenchyma injuries. There were 2 on-table deaths. Ninety-day mortality was 9.2%.

CONCLUSIONS

This study offers an overview of the range of different intraoperative complications during minimally invasive esophagectomy. Mortality, especially from intrathoracic vascular injuries, appears significant.

Fit-for-Discharge Criteria after Esophagectomy: An International Expert Delphi Consensus

There are no internationally recognized criteria available to determine preparedness for hospital discharge after esophagectomy. This study aims to achieve international consensus using Delphi methodology. The expert panel consisted of 40 esophageal surgeons spanning 16 countries and 4 continents. During a 3-round, web-based Delphi process, experts voted for discharge criteria using 5-point Likert scales. Data were analyzed using descriptive statistics. Consensus was reached if agreement was ≥75% in round 3. Consensus was achieved for the following basic criteria: nutritional requirements are met by oral intake of at least liquids with optional supplementary nutrition via jejunal feeding tube. The patient should have passed flatus and does not require oxygen during mobilization or at rest. Central venous catheters should be removed. Adequate analgesia at rest and during mobilization is achieved using both oral opioid and non-opioid analgesics. All vital signs should be normal unless abnormal preoperatively. Inflammatory parameters should be trending down and close to normal (leucocyte count ≤12G/l and C-reactive protein ≤80 mg/dl). This multinational Delphi survey represents the first expert-led process for consensus criteria to determine 'fit-for-discharge' status after esophagectomy. Results of this Delphi survey may be applied to clinical outcomes research as an objective measure of short-term recovery. Furthermore, standardized endpoints identified through this process may be used in clinical practice to guide decisions regarding patient discharge and may help to reduce the risk of premature discharge or prolonged admission.

Centralized repeated resectability assessment of patients with colorectal liver metastases during first-line treatment: prospective study

BACKGROUND

Metastasectomy is probably underused in metastatic colorectal cancer. The aim of this study was to investigate the effect of centralized repeated assessment on resectability rate of liver metastases.

METHODS

The prospective RAXO study was a nationwide study in Finland. Patients with treatable metastatic colorectal cancer at any site were eligible. This planned substudy included patients with baseline liver metastases between 2012 and 2018. Resectability was reassessed by the multidisciplinary team at Helsinki tertiary referral centre upfront and twice during first-line systemic therapy. Outcomes were resectability rates, management changes, and survival.

RESULTS

Of 812 patients included, 301 (37.1 per cent) had liver-only metastases. Of these, tumours were categorized as upfront resectable in 161 (53.5 per cent), and became amenable to surgery during systemic treatment in 63 (20.9 per cent). Some 207 patients (68.7 per cent) eventually underwent liver resection or ablation. At baseline, a discrepancy in resectability between central and local judgement was noted for 102 patients (33.9 per cent). Median disease-free survival (DFS) after first resection was 20 months and overall survival (OS) 79 months. Median OS after diagnosis of metastatic colorectal cancer was 80, 32, and 21 months in R0-1 resection, R2/ablation, and non-resected groups, and 5-year OS rates were 68, 37, and 9 per cent, respectively. Liver and extrahepatic metastases were present in 511 patients. Of these, tumours in 72 patients (14.1 per cent) were categorized as upfront resectable, and 53 patients (10.4 per cent) became eligible for surgery. Eventually 110 patients (21.5 per cent) underwent liver resection or ablation. At baseline, a discrepancy between local and central resectability was noted for 116 patients (22.7 per cent). Median DFS from first resection was 7 months and median OS 55 months. Median OS after diagnosis of metastatic colorectal cancer was 79, 42, and 17 months in R0-1 resection, R2/ablation, and non-resected groups, with 5-year OS rates of 65, 39, and 2 per cent, respectively.

CONCLUSION

Repeated centralized resectability assessment in patients with colorectal liver metastases improved resection and survival rates.

Ethical climate and moral distress in paediatric oncology nursing

BACKGROUND

Ethical climate and moral distress have been shown to affect nurses' ethical behaviour. Despite the many ethical issues in paediatric oncology nursing, research is still lacking in the field.

RESEARCH AIM

To investigate paediatric oncology nurses' perceptions of ethical climate and moral distress.

RESEARCH DESIGN

In this cross-sectional study, data were collected using Finnish translations of the Swedish Hospital Ethical Climate Survey-Shortened and the Swedish Moral Distress Scale-Revised. Data analysis includes descriptive statistics and non-parametric analyses.

RESPONDENTS AND RESEARCH CONTEXT

Ninety-three nurses, working at paediatric oncology centres in Finland, completed the survey.

ETHICAL CONSIDERATIONS

According to Finnish legislation, no ethical review was needed for this type of questionnaire study. Formal research approvals were obtained from all five hospitals. Return of the questionnaire was interpreted as consent to participate.

RESULTS

Ethical climate was perceived as positive. Although morally distressing situations were assessed as highly disturbing, in general they occurred quite rarely. The situations that did appear often reflected performing procedures on school-aged children who resist such treatment, inadequate staffing and lack of time. Perceptions of ethical climate and frequencies of morally distressing situations were inversely correlated.

DISCUSSION

Although the results echo the recurrent testimonies of busy work shifts, nurses could most often practise nursing the way they perceived as right. One possible explanation could be the competent and supportive co-workers, as peer support has been described as helpful in mitigating moral distress.

CONCLUSION

Nurturing good collegial relationships and developing manageable workloads could reduce moral distress among nurses.

Hyperspectral Imaging Reveals Spectral Differences and Can Distinguish Malignant Melanoma from Pigmented Basal Cell Carcinomas: A Pilot Study

Pigmented basal cell carcinomas can be difficult to distinguish from melanocytic tumours. Hyperspectral imaging is a non-invasive imaging technique that measures the reflectance spectra of skin in vivo. The aim of this prospective pilot study was to use a convolutional neural network classifier in hyperspectral images for differential diagnosis between pigmented basal cell carcinomas and melanoma. A total of 26 pigmented lesions (10 pigmented basal cell carcinomas, 12 melanomas in situ, 4 invasive melanomas) were imaged with hyperspectral imaging and excised for histopathological diagnosis. For 2-class classifier (melanocytic tumours vs pigmented basal cell carcinomas) using the majority of the pixels to predict the class of the whole lesion, the results showed a sensitivity of 100% (95% confidence interval 81–100%), specificity of 90% (95% confidence interval 60–98%) and positive predictive value of 94% (95% confidence interval 73–99%). These results indicate that a convolutional neural network classifier can differentiate melanocytic tumours from pigmented basal cell carcinomas in hyperspectral images. Further studies are warranted in order to confirm these preliminary results, using larger samples and multiple tumour types, including all types of melanocytic lesions.

Hexyl aminolevulinate, 5-aminolevulinic acid nanoemulsion and methyl aminolevulinate in photodynamic therapy of non-aggressive basal cell carcinomas: A non-sponsored, randomized, prospective and double-blinded trial

BACKGROUND

In the photodynamic therapy (PDT) of non-aggressive basal cell carcinomas (BCCs), 5-aminolevulinic acid nanoemulsion (BF-200ALA) has shown non-inferior efficacy when compared with methyl aminolevulinate (MAL), a widely used photosensitizer. Hexyl aminolevulinate (HAL) is an interesting alternative photosensitizer. To our knowledge, this is the first study using HAL-PDT in the treatment of BCCs.

OBJECTIVES

To compare the histological clearance, tolerability (pain and post-treatment reaction) and cosmetic outcome of MAL, BF-200 ALA and low-concentration HAL in the PDT of non-aggressive BCCs.

METHODS

Ninety-eight histologically verified non-aggressive BCCs met the inclusion criteria, and 54 patients with 95 lesions completed the study. The lesions were randomized to receive LED-PDT in two repeated treatments with MAL, BF-200 ALA or HAL. Efficacy was assessed both clinically and confirmed histologically at three months by blinded observers. Furthermore, cosmetic outcome, pain, post-treatment reactions fluorescence and photobleaching were evaluated.

RESULTS

According to intention-to-treat analyses, the histologically confirmed lesion clearance was 93.8% (95% confidence interval [CI] = 79.9-98.3) for MAL, 90.9% (95% CI = 76.4-96.9) for BF-200 ALA and 87.9% (95% CI = 72.7-95.2) for HAL, with no differences between the arms (P = 0.84). There were no differences between the arms as regards pain, post-treatment reactions or cosmetic outcome.

CONCLUSIONS

Photodynamic therapy with low-concentration HAL and BF-200 ALA has a similar efficacy, tolerability and cosmetic outcome compared to MAL. HAL is an interesting new option in dermatological PDT, since good efficacy is achieved with a low concentration.

Diagnostic criteria and symptom grading for delayed gastric conduit emptying after esophagectomy for cancer: international expert consensus based on a modified Delphi process

Delayed gastric conduit emptying (DGCE) after esophagectomy for cancer is associated with adverse outcomes and troubling symptoms. Widely accepted diagnostic criteria and a symptom grading tool for DGCE are missing. This hampers the interpretation and comparison of studies. A modified Delphi process, using repeated web-based questionnaires, combined with live interim group discussions was conducted by 33 experts within the field, from Europe, North America, and Asia. DGCE was divided into early DGCE if present within 14 days of surgery and late if present later than 14 days after surgery. The final criteria for early DGCE, accepted by 25 of 27 (93%) experts, were as follows: >500 mL diurnal nasogastric tube output measured on the morning of postoperative day 5 or later or >100% increased gastric tube width on frontal chest x-ray projection together with the presence of an air-fluid level. The final criteria for late DGCE accepted by 89% of the experts were as follows: the patient should have 'quite a bit' or 'very much' of at least two of the following symptoms; early satiety/fullness, vomiting, nausea, regurgitation or inability to meet caloric need by oral intake and delayed contrast passage on upper gastrointestinal water-soluble contrast radiogram or on timed barium swallow. A symptom grading tool for late DGCE was constructed grading each symptom as: 'not at all', 'a little', 'quite a bit', or 'very much', generating 0, 1, 2, or 3 points, respectively. For the five symptoms retained in the diagnostic criteria for late DGCE, the minimum score would be 0, and the maximum score would be 15. The final symptom grading tool for late DGCE was accepted by 27 of 31 (87%) experts. For the first time, diagnostic criteria for early and late DGCE and a symptom grading tool for late DGCE are available, based on an international expert consensus process.

The implementation of a nationwide anomaly screening programme improves prenatal detection of major cardiac defects: an 11-year national population-based cohort study

OBJECTIVE

To evaluate whether a nationwide prenatal anomaly screening programme improves detection rates of univentricular heart (UVH) and transposition of great arteries (TGA), and whether maternal risk factors for severe fetal heart disease affect prenatal detection.

DESIGN

Population-based cohort study.

SETTING

Nationwide data from Finnish registries 2004-14.

POPULATION

A total of 642 456 parturients and 3449 terminated pregnancies due to severe fetal anomaly.

METHODS

Prenatal detection rates were calculated in three time periods (prescreening, transition and screening phase). The effect of maternal risk factors (obesity, in vitro fertilisation, pregestational diabetes and smoking) was evaluated.

MAIN OUTCOME MEASURES

Change in detection rates and impact of maternal risk factors on screening programme efficacy.

RESULTS

In total, 483 cases of UVH and 184 of TGA were detected. The prenatal detection rate of UVH increased from 50.4% to 82.8% and of TGA from 12.3% to 41.0% (P < 0.0001). Maternal risk factors did not affect prenatal detection rate, but detection rate differed substantially by region.

CONCLUSIONS

A nationwide screening programme improved overall UVH and TGA detection rates, but regional differences were observed. Obesity or other maternal risk factors did not affect the screening programme efficacy. The establishment of structured guidelines and recommendations is essential when implementing the screening programme. In addition, a prospective screening register is highly recommended to ensure high quality of screening.

TWEETABLE ABSTRACT

Implementation of a nationwide prenatal anomaly screening improved detection rates of UVH and TGA.

Multicentre randomized clinical trial of inspiratory muscle training versus usual care before surgery for oesophageal cancer

Background

Up to 40 per cent of patients undergoing oesophagectomy develop pneumonia. The aim of this study was to assess whether preoperative inspiratory muscle training (IMT) reduces the rate of pneumonia after oesophagectomy.

Methods

Patients with oesophageal cancer were randomized to a home-based IMT programme before surgery or usual care. IMT included the use of a flow-resistive inspiratory loading device, and patients were instructed to train twice a day at high intensity (more than 60 per cent of maximum inspiratory muscle strength) for 2 weeks or longer until surgery. The primary outcome was postoperative pneumonia; secondary outcomes were inspiratory muscle function, lung function, postoperative complications, duration of mechanical ventilation, length of hospital stay and physical functioning.

Results

Postoperative pneumonia was diagnosed in 47 (39·2 per cent) of 120 patients in the IMT group and in 43 (35·5 per cent) of 121 patients in the control group (relative risk 1·10, 95 per cent c.i. 0·79 to 1·53; P = 0·561). There was no statistically significant difference in postoperative outcomes between the groups. Mean(s.d.) maximal inspiratory muscle strength increased from 76·2(26·4) to 89·0(29·4) cmH2O (P &lt; 0·001) in the intervention group and from 74·0(30·2) to 80·0(30·1) cmH2O in the control group (P &lt; 0·001). Preoperative inspiratory muscle endurance increased from 4 min 14 s to 7 min 17 s in the intervention group (P &lt; 0·001) and from 4 min 20 s to 5 min 5 s in the control group (P = 0·007). The increases were highest in the intervention group (P &lt; 0·050).

Conclusion

Despite an increase in preoperative inspiratory muscle function, home-based preoperative IMT did not lead to a decreased rate of pneumonia after oesophagectomy. Registration number: NCT01893008 (https://www.clinicaltrials.gov).

Boerhaave’s Syndrome: Lessons Learned from 83 Cases over Three Decades

The authors describe their experience in the treatment of 83 Boerhaave patients. During the last few years the mortality of the disease has decreased. A successful treatment requires good treatment resources and experienced team work. The tailored open primary repair technique with fundic reinforcement, developed by the authors, is described in detail. This technique has decreased the amount of postoperative fistulation and esophageal resection. The mortality after stenting was 20%.

Alcohol-induced premature permeability in mouse placenta-yolk sac barriers in vivo

OBJECTIVE

Acute alcohol exposure induces malformation and malfunction of placenta-yolk sac tissues in rodents, reducing the labyrinth zone in the placenta and altering the permeability and fluidity of the cell membrane. During normal mouse placentation the cells line up in an optimal way to form a hemotrichorial placenta where layers II and III are connected through gap junctions. These act as molecular sieves that limit the passage of large molecules. PlGF is a developmentally regulated protein that controls the passage of molecules in the vasculosyncytial membranes and media of large blood vessels in the placental villi. In addition to the chorioallontoic placenta, rodents also have another type of placenta that consists of Reichert's membrane within the trophoblast cell layer on the maternal side and the parietal endodermal cells on the embryonic site. This forms a separate materno-fetal transport system. We study here whether alcohol affects these two placental barriers, leading to placental malfunction that in turn diminishes the nutrient supply to the embryo.

STUDY DESIGN

CD-1 mice received two intraperitoneal injections of 3 g/kg ethanol at 4 h intervals at 8.75 days post coitum (dpc). The placentas were collected on 9.5, 11.5 and 14.5 dpc and used for histopathological protein studies. Hemotrichorial cell layer structure interactions through connective tissue and gap junction were analyzed by electron microscopy. The permeability of the feto-maternal barrier was visualized with Evans Blue.

RESULTS

VEGF, a permeability inducer, was found to be up-regulated in the mouse placenta after acute alcohol exposure, and permeability was also affected by altered structures in the barriers that separate the feto-maternal blood circulation which destroyed the gap junctions in the hemotrichorial cell layer, reduced the thickness of Reichert's membrane and interfered with with Reichert's trophoblast/Reichert's parietal interaction. These defects together could have caused the permeability malfunction of the placenta-yolk sac tissues as visualized and quantified here by Evans Blue leakage.

CONCLUSIONS

An altered PlGF/VEGF ratio together with barrier malformation may contribute to placental malfunction by altering the permeability of the feto-maternal barriers. Further studies are needed in order to show whether premature permeability is involved in the intrauterine growth restriction observed in human FAS embryos.

Impact of perceptual ability and mental imagery training on simulated laparoscopic knot-tying in surgical novices using a Nissen fundoplication model

BACKGROUND

Performing minimally invasive surgery requires training and visual-spatial intelligence. The aim of our study was to examine the impact of visual-spatial perception and additional mental training on the simulated laparoscopic knot-tying task performed by surgical novices.

METHODS

A total of 40 medical students randomly assigned to two groups underwent two sessions of laparoscopic basic training on a VR simulator (SimSurgery®, Oslo, Norway). The variables time and tip trajectory (total path length of the instrument tip trajectory) were used to assess the performance of the intracorporeal knot-tying task using a laparoscopic Nissen fundoplication model. The experimental group completed additional mental practice during the interval between the two training sessions. All performed a cube subtest of a standard intelligence test (I-S-T 2000 R) to evaluate visual-spatial ability.

RESULTS

All participants achieved an improvement in time (t = 9.861; p < 0.001) and tip trajectory (t = 6.833; p < 0.001) in the second training session. High scores on the visual-spatial test correlated with a faster performance (r = -0.557; p < 0.001) and more precise movements (r = -0.377; p = 0.016). Comparison of the two groups did not show any statistical significant differences in the parameters time and tip trajectory.

CONCLUSIONS

Visual-spatial intelligence tested by a cube test correlated with simulated laparoscopic knot-tying skills in surgical novices. Additional mental practice did not improve the overall knot-tying performance. Further studies are therefore required to determine whether mental practice might be beneficial for experienced laparoscopic surgeons or for more complex tasks.

Significance of retrograde diastolic uterine artery blood flow during regional anesthesia in instrumented pregnant sheep

BACKGROUND

We studied the interactions between uterine and placental hemodynamics during maternal hypotension in chronically instrumented fetal sheep. In addition, we investigated maternal hemodynamic characteristics, fetoplacental hemodynamics and fetal acid-base status when a retrograde diastolic uterine artery blood flow pattern is present during maternal hypotension.

METHODS

Invasive maternal and fetal hemodynamic parameters, uterine (Q(UtA)) and placental (Q(UA)) volume blood flows and acid-base values were examined in 24 chronically instrumented sheep at baseline and during epidural-induced maternal hypotension at 117-132 (term 145) days of gestation. Uterine artery blood flow velocity waveforms were obtained by Doppler ultrasonography.

RESULTS

Maternal hypotension decreased Q(UtA) without affecting Q(UA). During hypotension, eight out of 24 sheep demonstrated a retrograde diastolic blood flow velocity waveform pattern in the uterine artery. Maternal systolic, diastolic and mean arterial blood pressures were significantly lower in the retrograde group than in the antegrade group. No statistically significant differences in Q(UtA), Q(UA) and fetal blood gas values were detected between the two groups during hypotension.

CONCLUSIONS

An acute decrease in uterine artery volume blood flow during maternal hypotension is not compensated by increased placental volume blood flow. A retrograde diastolic blood flow pattern in the uterine artery is related to lower maternal arterial pressures, especially during diastole. A uterine artery retrograde diastolic blood flow pattern does not have any additional detrimental short-term effects on fetal acid-base status.

Low-dose aspirin reduces uteroplacental vascular impedance in early and mid gestation in IVF and ICSI patients: a randomized, placebo-controlled double-blind study

OBJECTIVE

To determine whether low-dose aspirin improves uteroplacental hemodynamics in unselected in-vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) subjects when medication is started concomitantly with controlled ovarian hyperstimulation.

METHODS

Thirty-seven pregnant women who had undergone IVF/ICSI and had been randomized to receive 100 mg aspirin (n = 17) or placebo (n = 20) daily, started concomitantly with controlled ovarian hyperstimulation, were included in this study. Doppler ultrasound examination was performed at 6, 10, 13 and 18 weeks' gestation. Uterine artery (UtA) pulsatility index (PI) was calculated and bilateral UtA notching was noted. Subplacental arcuate artery PI was obtained at 6 and 10 weeks' gestation. Umbilical artery (UA) PI and mean velocity were calculated at 10, 13 and 18 weeks' gestation. In the aspirin group there was one early pregnancy miscarriage, and one patient discontinued the study medication owing to early pregnancy bleeding. A total of 15 women in the aspirin group and 20 women in the placebo group underwent the complete ultrasound protocol.

RESULTS

At 6 weeks' gestation, arcuate artery PI and at 18 weeks' gestation, UtA PI were lower (P < 0.05) in the aspirin group than in the placebo group. At 18 weeks' gestation, bilateral UtA notching tended to be more common in the placebo group (40%) than in the aspirin group (13%) (P = 0.06). UA PI and mean velocity did not differ significantly between the groups.

CONCLUSION

Low-dose aspirin reduces uteroplacental vascular impedance in early and mid pregnancy in unselected IVF/ICSI subjects when medication is started concomitantly with controlled ovarian hyperstimulation.

Long-term indwelling pleural catheter (PleurX) for malignant pleural effusion unsuitable for talc pleurodesis

AIMS

Talc pleurodesis using talc slurry via chest tube is a primary option in malignant pleural effusion, since life expectancy is short and surgical decortication is hazardous. Incomplete lung expansion after fluid evacuation, and/or excessive fluid secretion predicts failure of pleurodesis. A mini-invasive alternative was investigated.

METHODS

Between March 2004 and September 2005, 51 consecutive patients with malignant pleural effusion, and clinically considered unsuitable for talc pleurodesis, received an indwelling pleural catheter (Denver PleurX). In 47, implantation was done bedside using local anaesthesia. There were 24 men and 27 women, median age 63 (range 36-85) years, receiving 39 right side, 10 left side, and 2 bilateral catheters. There were 19 non-small cell lung cancer cases, 7 mesothelioma, and 25 with other malignancy. Chemotherapy was being given to 18 patients and was not interrupted.

RESULTS

Discharge to home was possible in 71% (36 of 71 patients) on the following day. At 2 years follow-up in September 2007, one patient was alive. Mean survival was 3 months (range 5 days to 37+months) for all patients, with best median survivals of 5.5-6 months in breast and ovarian cancer. Catheter was removed or replaced in 15% (8 of 51 patients) due to infection, air leak, or blockage. One patient requested decortication for excessive fluid secretion. None required surgery or died due to catheter-related complications. Pleural fusion with subsequent catheter removal was achieved in 21% (11 of 51 patients).

CONCLUSIONS

An indwelling pleural catheter is a safe alternative for patients with malignant pleural effusion unsuitable for talc pleurodesis. In some, pleural fusion may be achieved.

Human fetal cardiovascular profile score and neonatal outcome in intrauterine growth restriction

OBJECTIVE

To determine whether low cardiovascular profile (CVP) score has prognostic value for predicting neonatal mortality and severe morbidity in human fetuses with growth restriction.

METHODS

Seventy-five consecutive growth-restricted fetuses with Doppler examination of cardiovascular hemodynamics within a week prior to delivery comprised the study population. Hydrops, heart size, cardiac function and venous and arterial hemodynamics were evaluated for CVP score. The primary outcome measures were neonatal mortality and cerebral palsy.

RESULTS

During the neonatal period, six of 75 neonates died and two had cerebral palsy (Group 1, n = 8). Compared with the fetuses discharged home from hospital (Group 2, n = 67), those in Group 1 were delivered at an earlier gestational age (28 (range, 24-35) weeks vs. 35 (range, 26-40) weeks, P < 0.01) and had lower CVP scores (4 (range, 2-6) vs. 9 (range, 5-10), P < 0.0001). All CVP subscale scores were lower (P < 0.01) in Group 1 than in Group 2 fetuses. Gestational age-adjusted hazard ratios (95% CIs) for adverse neonatal outcome were highest for cardiomegaly (13.9 (1.7-114.3), P = 0.014), monophasic atrioventricular filling pattern or holosystolic tricuspid regurgitation (9.5 (2.3-38.4), P = 0.002) and atrial pulsations in the umbilical vein 7.7 (1.4-41.2), P = 0.017).

CONCLUSIONS

Growth-restricted fetuses with adverse neonatal outcome have lower CVP scores than do fetuses with favorable neonatal outcome. The strongest predictors for adverse neonatal outcome in the CVP score were cardiomegaly, abnormal cardiac function with monophasic atrioventricular filling or holosystolic tricuspid regurgitation and increased systemic venous pressure. These assessments have independent prognostic power for adverse neonatal outcome even after adjustment for gestational age.

Divergent effects of ephedrine and phenylephrine on cardiovascular hemodynamics of near-term fetal sheep exposed to hypoxemia and maternal hypotension

BACKGROUND

We hypothesized that the administration of ephedrine and phenylephrine for maternal hypotension modifies cardiovascular hemodynamics in near-term sheep fetuses.

METHODS

At 115-136 days of gestation, chronically instrumented, anesthetized ewes with either normal placental function or increased placental vascular resistance after placental embolization were randomized to receive boluses of ephedrine (n = 12) or phenylephrine (n = 12) for epidural-induced hypotension after a short period of hypoxemia. Fetal cardiovascular hemodynamics were assessed by Doppler ultrasonography at baseline, during hypotension and after vasopressor treatment.

RESULTS

During hypotension, fetal PO(2) decreased and proximal branch pulmonary arterial and pulmonary venous vascular impedances increased. Additionally, in the embolized fetuses, the time-velocity integral ratio between the antegrade and retrograde blood flow components of the aortic isthmus decreased. These parameters were restored to baseline conditions by ephedrine but not by phenylephrine. With phenylephrine, weight-indexed left ventricular cardiac output and ejection force decreased in the non-embolized fetuses, and the proportion of isovolumetric contraction time of the total cardiac cycle was elevated in the embolized fetuses.

CONCLUSIONS

After exposure to hypoxemia and maternal hypotension, ephedrine restored all fetal cardiovascular hemodynamic parameters to baseline. Phenylephrine did not reverse fetal pulmonary vasoconstriction or the relative decrease in the net forward flow through the aortic isthmus observed in fetuses with increased placental vascular resistance. Moreover, fetal left ventricular function was impaired during phenylephrine administration.

Experimental validation of uterine artery volume blood flow measurement by Doppler ultrasonography in pregnant sheep

OBJECTIVE

To test the hypothesis that Doppler-derived (calculated) uterine artery volume blood flow (cQ(UtA)) reflects accurately volume blood flow measured directly (mQ(UtA)) in an experimental setting.

METHODS

Five pregnant sheep were instrumented at 122-130 days of gestation under general anesthesia. After a 4-day recovery period, maternal hemodynamics were varied by administering to the sheep under general anesthesia noradrenaline, beta-blocker, low oxygen gas mixture, epidural bupivacaine and ephedrine, consecutively. The central venous pressure was obtained with the help of a thermodilution catheter. The mean arterial pressure and acid-base status were monitored using a 16-gauge polyurethane catheter inserted into the descending aorta via a femoral artery. A 6-mm transit-time ultrasonic perivascular flow probe was used to measure the mQ(UtA). Doppler ultrasonography of the uterine artery was performed and volume blood flow was obtained simultaneously by the transit-time ultrasonic perivascular flow probe during each phase of the experiment.

RESULTS

A total of 31 observations were made. The mQ(UtA) varied between 90 and 800 (mean +/- SD, 419 +/- 206) mL/min during the experiments. The corresponding values for the cQ(UtA) were 110 and 900 (mean +/- SD, 459 +/- 211) mL/min. There was a significant correlation (R = 0.76; P < 0.0001) between mQ(UtA) and cQ(UtA). The mQ(UtA) correlated positively with Doppler-derived uterine artery absolute velocities, i.e. peak systolic (R = 0.50; P = 0.004), end-diastolic (R = 0.53; P = 0.002) and time-averaged maximum (R = 0.69; P < 0.0001) and time-averaged intensity weighted mean (R = 0.75; P < 0.0001) velocities.

CONCLUSION

cQ(UtA) correlates well with volume blood flow measured directly. Doppler-derived uterine artery absolute blood flow velocities reflect uteroplacental volume blood flow in pregnant sheep. Published by John Wiley & Sons, Ltd.

Cardiovascular hemodynamics and umbilical artery N-terminal peptide of proB-type natriuretic peptide in human fetuses with growth restriction

OBJECTIVE

To test our hypothesis that human fetal N-terminal peptide of proB-type natriuretic peptide (NT-proBNP) secretion is increased in proportion to the severity of fetal cardiovascular compromise in intrauterine growth restriction.

METHODS

This prospective cross-sectional study consisted of 42 growth-restricted fetuses who underwent Doppler ultrasonographic examination of cardiovascular hemodynamics within 7 days before delivery. Group 1 fetuses (n = 13) had normal umbilical artery (UA) velocimetry. Group 2 fetuses (n = 15) had abnormal UA and normal ductus venosus (DV) velocimetry. In Group 3 fetuses (n = 14), both UA and DV velocimetries were abnormal. At delivery, an UA blood sample was obtained for assessment of NT-proBNP. Normal values for UA NT-proBNP were determined in 49 neonates (control group) with uncomplicated pregnancy and delivery.

RESULTS

Group 3 fetuses demonstrated greater (P < 0.05) UA and descending aorta pulsatility indices (PIs) and greater DV, left hepatic vein (LHV) and inferior vena cava PIs for veins (PIVs) than fetuses in Groups 1 and 2. Weight-indexed cardiac outputs and ventricular ejection forces were similar among the groups. Group 3 fetuses had higher (P < 0.05) UA NT-proBNP concentration than fetuses in Groups 1 and 2. In the control group, the 95(th) percentile value of UA NT-proBNP was 518 pmol/L. In Group 3, 13/14 neonates demonstrated abnormal UA NT-proBNP levels. The corresponding incidences were 4/13 and 7/15 in Groups 1 and 2. Significant positive correlations were found between UA, DV and LHV PIVs and UA NT-proBNP concentrations.

CONCLUSION

In human fetal growth restriction, increased cardiac afterload and pulsatility in DV blood velocity waveform pattern are associated with elevated UA NT-proBNP concentrations.

Genome-controlled reverse transcriptase-polymerase chain reaction for targeted gene-expression analysis

OBJECTIVE

Although gene-expression profiling has an important part to play in the classification of tumours and premalignant conditions, reproducibility of the present polymerase chain reaction (PCR)-based quantitative techniques needs to be improved for diagnostic purposes and to enable analysis of gene expression in formalin-fixed paraffin-embedded (FFPE) tissue samples. We have developed reverse transcriptase-PCR-based technology for quantitative assessment of the relative content of multiple mRNA transcripts in small tissue or cell samples.

MATERIAL AND METHODS

A multiplexed sequence modifying cDNA synthesis reaction is performed with this technique to create a 4-5 degrees increase in the melting temperature of subsequent short (56-64 bp) PCR amplicons. Each cDNA template is competitively co-amplified with genomic DNA, which serves as a universal internal standard. The relative amounts of cDNA and genomic DNA-derived amplicons are quantified in-tube by homogeneous melting curve analysis.

RESULTS

The dynamic range of the assay was three orders of magnitude, while the detection limit was 100 cDNA molecules. A prototype assay, consisting of the analysis of eight genes, displayed good reproducibility (inter-assay CV 5-20 %) compared to the TaqMan assay (inter-assay CV 7-43 %). Gene-expression analysis could be performed in 20 of 20 (100 %) archival frozen samples, in 30 of 35 (86 %) archival FFPE samples and in 26 of 27 (96 %) endoscopic biopsies.

CONCLUSIONS

We demonstrate that this new technique enables accurate analysis of mRNA expression in cultured cells and endoscopic tissue biopsies. Sensitive analysis FFPE tissue is also possible thanks to the short PCR amplicons.

Isoprene emission from a subarctic peatland under enhanced UV-B radiation

Isoprene is a reactive hydrocarbon with an important role in atmospheric chemistry, and emissions from vegetation contribute to atmospheric carbon fluxes. The magnitude of isoprene emissions from arctic peatlands is not known, and it may be altered by increasing UV-B radiation. Isoprene emission was measured with the dynamic chamber method from a subarctic peatland under long-term enhancement of UV-B radiation targeted to correspond to a 20% loss in the stratospheric ozone layer. The site type of the peatland was a flark fen dominated by the moss Warnstorfia exannulata and sedges Eriophorum russeolum and Carex limosa. The relationship between species densities and the emission was also assessed. Isoprene emissions were significantly increased by enhanced UV-B radiation during the second (2004) and the fourth (2006) growing seasons under the UV-B exposure. Emissions were related to the density of E. russeolum. The dominant moss, W. exannulata, proved to emit small amounts of isoprene in a laboratory trial. Subarctic fens, even without Sphagnum moss, are a significant source of isoprene to the atmosphere, especially under periods of warm weather. Warming of the Arctic together with enhanced UV-B radiation may substantially increase the emissions.

Ephedrine and phenylephrine for the treatment of maternal hypotension in a chronic sheep model of increased placental vascular resistance †

BACKGROUND

We hypothesized that ephedrine and phenylephrine are equal with respect to uterine and placental haemodynamics and fetal acid-base status after exposure to maternal hypoxaemia and hypotension in a chronic sheep model of increased placental vascular resistance (R(UA)).

METHODS

At 114-135 days gestation, chronically instrumented fetal sheep underwent placental embolization leading to increased R(UA). Twenty-four hours after embolization, the ewes were anaesthetized and randomized to receive boluses of ephedrine (n=7) or phenylephrine (n=6) for epidural-induced hypotension after maternal hypoxaemia. Uterine (Q(UtA)) and placental (Q(UA)) volume blood flows and uterine vascular resistance (R(UtA)) and R(UA) were recorded. Uterine (PI(UtA)) and umbilical artery (PI(UA)) pulsatility indices were obtained by Doppler ultrasonography. Fetal arterial blood samples were analysed for acid-base values and lactate concentrations.

RESULTS

During hypotension, Q(UtA), fetal pH, BE, and Po(2) decreased whereas R(UtA), PI(UtA), R(UA), and fetal lactate concentration increased. With ephedrine, Q(UtA), R(UtA), PI(UtA), R(UA), and fetal Po(2) returned to baseline. Fetal pH, BE, and lactate concentration did not change from hypotensive values. With phenylephrine, Q(UtA) remained lower (P=0.007) and R(UtA) (P=0.007), PI(UtA) (P=0.013), and R(UA) (P=0.050) higher than at baseline. Fetal Po(2) returned to baseline and fetal pH and BE did not change from hypotensive values. However, fetal lactate concentration increased further (mean difference 1.49, 95% confidence interval 0.72-2.26 mmol litre(-1); P=0.004).

CONCLUSIONS

In a chronic sheep model of increased placental vascular resistance, compared with ephedrine administration, phenylephrine administration was associated with impaired uterine and placental haemodynamics and increased fetal lactate concentrations.

Low-dose aspirin does not improve ovarian responsiveness or pregnancy rate in IVF and ICSI patients: a randomized, placebo-controlled double-blind study

BACKGROUND

Poor ovarian and endometrial responses to gonadotrophin stimulation in assisted reproduction techniques lead to decreased pregnancy rates. The aim of the present study was to test the hypothesis that low-dose aspirin started prior to controlled ovarian stimulation improves ovarian responsiveness, pregnancy rate (PR) and pregnancy outcome.

METHODS

A total of 374 women who were to undergo IVF/ICSI were randomized to receive 100 mg of aspirin (n=186) or placebo (n=188) daily. Treatment was started on the first day of controlled ovarian stimulation. It was continued until menstruation or a negative pregnancy test. Pregnant women continued the medication until delivery. The main outcome measures were the number of oocytes, number and quality of embryos, the clinical PR and pregnancy outcome.

RESULTS

The mean (+/-SD) number of oocytes (12.0+/-7.0 versus 12.7+/-7.2), the total mean number of embryos (5.82+/-4.35 versus 5.99+/-4.66), the mean number of top quality embryos (0.99+/-1.39 versus 1.18+/-1.51) and the number of embryos transferred (1.64+/-0.64 versus 1.63+/-0.71) did not differ in the aspirin and placebo groups. Between the aspirin and placebo group, there was no statistically significant difference in clinical PR per embryo transfer (25.3%, n=44 out of 174 versus 27.4%, n=48 out of 175) or clinical PR per cycle initiated (23.7% versus 25.5%). Birth rate per embryo transfer did not differ significantly between the aspirin (18.4%) and placebo (21.1%) groups. The incidence of poor responders [12 (6.5%) versus 13 (6.9%)] was similar in both groups.

CONCLUSIONS

The present results indicate that low-dose aspirin treatment does not have any beneficial effect on ovarian responsiveness, PR and pregnancy outcome in unselected women undergoing IVF/ICSI.

Human fetal cardiac function during the first trimester of pregnancy

OBJECTIVE

To investigate first trimester human fetal cardiac function in relation to cardiac volume blood flow, and peripheral arterial and venous blood flow patterns.

METHODS

Transvaginal Doppler ultrasonography was performed in 16 uncomplicated pregnancies at 6+, 7+, 8+, 9+, and 10+ gestational weeks. The shape of the inflow waveform and the presence of atrioventricular valve regurgitation (AVVR) were noted. The outflow mean velocity (Vmean) was calculated. The proportions of the isovolumetric relaxation (IRT%) and contraction times (ICT%) of the cardiac cycle were defined. Ductus venosus and umbilical artery pulsatility indices (PI) were obtained.

RESULTS

Every inflow waveform was monophasic before 9+ weeks. At 9+ weeks 11 of 16 and at 10+ weeks all waveforms were biphasic. At 7+ and 8+ weeks AVVR was documented in one case. At 9+ and 10+ weeks AVVR was present in four and seven fetuses, respectively. Mean (SD) outflow Vmean increased between 6+ and 8+ weeks from 3.6 (1.5) to 8.4 (3.0) cm/s (p < 0.05). IRT% decreased significantly from 6+ to 7+ weeks (39.8 (2.6) to 19.2 (6.2), p < 0.001). ICT% decreased between 8+ and 9+ weeks from 13.2 (4.0) to 8.5 (2.5) (p < 0.05). Ductus venosus PIs were unchanged. Umbilical artery Vmean increased between 7+ and 10+ weeks from 1.59 (0.51) to 5.06 (1.06) cm/s (p < 0.001) and PIs remained unchanged.

CONCLUSIONS

The first trimester of pregnancy is characterised by significant improvements in cardiac diastolic and systolic function with a concomitant increase in cardiac volume blood flow. At 10+ weeks AVVR is a common finding. Placental volume blood flow increases significantly with no change in the placental vascular impedance.

Effects of ephedrine and phenylephrine on uterine and placental circulations and fetal outcome following fetal hypoxaemia and epidural-induced hypotension in a sheep model †

BACKGROUND

Recent studies support the use of alpha-agonists during regional anaesthesia in uncomplicated term pregnancies. We hypothesized that ephedrine and phenylephrine, administered for maternal hypotension following fetal hypoxaemia, are equal in respect of fetal outcome.

METHODS

At 117-132 days gestation, chronically instrumented, anaesthetized and mechanically ventilated ewes were randomized to receive boluses of ephedrine (n=9) or phenylephrine (n=8) for maternal epidural-induced hypotension after a period of fetal hypoxaemia. Uterine (QUtA) and placental (QUA) volume blood flows were measured with perivascular transit-time ultrasonic flow probes, and uterine (RUtA) and placental (RUA) vascular resistances were computed from volume blood flows and maternal and fetal mean arterial pressures. Uterine (PIUtA) and umbilical artery (PIUA) pulsatility indices were obtained by Doppler ultrasonography.

RESULTS

Ephedrine increased QUtA and decreased RUtA and PIUtA from a hypotensive to baseline level and had no significant effect on umbilical circulation. With phenylephrine, QUtA remained lower (P=0.011) and RUtA higher (P=0.043) than at baseline, although PIUtA decreased to baseline level. PIUA increased from baseline with phenylephrine (P=0.007), whereas QUA decreased (P=0.050). Maternal volume expansion with hydroxyethyl starch decreased RUtA significantly irrespective of the vasopressor used. There were no significant differences in fetal blood gas values or lactate concentrations between the ephedrine and phenylephrine groups.

CONCLUSIONS

Despite the more favourable effects on uterine and placental circulations of ephedrine over phenylephrine, no significant differences in fetal acid-base status or lactate concentrations were observed.

Retrograde aortic isthmus net blood flow and human fetal cardiac function in placental insufficiency

OBJECTIVE

Retrograde aortic isthmus (AoI) net blood flow has been associated with diminished oxygen delivery to cerebral circulation. This study was designed to characterize the cardiac function in human fetuses with retrograde AoI net blood flow in pregnancies complicated by placental insufficiency.

METHODS

The control group comprised 43 fetuses in uncomplicated pregnancies. Study groups consisted of fetuses with placental insufficiency, and either antegrade (Group 1; n = 18) or retrograde (Group 2; n = 11) AoI net blood flow. Volume blood flows (Q) of left (LVCO) and right (RVCO) ventricles, ductus arteriosus (Q(DA)), pulmonary arterial bed (Q(P)) and foramen ovale (Q(FO)) were calculated and their proportions (%) of combined cardiac output (CCO) were determined. Ventricular ejection forces were calculated. Blood velocity waveforms of the mitral (MV) and tricuspid (TV) valves were obtained. The proportion of left ventricular isovolumetric relaxation time (IRT%) of the cardiac cycle, and index of myocardial performance (IMP) were calculated.

RESULTS

In Group 1, Q(DA)% was increased (P < 0.05) and Q(P)% decreased (P < 0.05) compared with the control group, and Q(FO)% was greater (P < 0.01) compared with the control group and Group 2. In Group 2, the distribution of CCO did not differ from that of the control group. Ventricular ejection forces were similar among the groups. In Group 2, the MV early filling/atrial contraction time-velocity integral ratio was greater (P < 0.05) compared with those of the control group and Group 1. In Groups 1 and 2, IRT% and IMP were increased (P < 0.001) compared with the control group.

CONCLUSIONS

In placental insufficiency, fetuses with antegrade AoI net blood flow show a shift in RVCO from the pulmonary to the systemic circulation, and Q(FO) makes up the majority of LVCO. Fetuses with retrograde AoI net blood flow fail to demonstrate these changes, suggesting a relative drop in the oxygen content of the blood entering the left ventricle.

Retrograde net blood flow in the aortic isthmus in relation to human fetal arterial and venous circulations

OBJECTIVES

To characterize changes in the human fetal arterial and venous circulations associated with retrograde aortic isthmus net blood flow.

METHODS

Study groups consisted of fetuses with placental insufficiency and/or fetal growth restriction and either antegrade (Group 1; n = 18) or retrograde (Group 2; n = 11) net blood flow in the aortic isthmus. The control group comprised 31 fetuses in uncomplicated pregnancies. Pulsatility indices of the umbilical, middle cerebral and proximal pulmonary arteries and the descending aorta, and pulsatility indices for veins of the ductus venosus and inferior vena cava were calculated. Right and left ventricular fractional shortenings were ascertained. The coronary artery blood flow was visualized and the presence of tricuspid regurgitation was noted.

RESULTS

In the study groups, the umbilical artery and descending aorta pulsatility indices were significantly higher (P < 0.05), and those of the middle cerebral artery lower (P < 0.001), than in the control group, with no difference between the two study groups. The proximal pulmonary artery pulsatility index was significantly higher in Group 2 (P < 0.001) than in Group 1 and the control group. In Group 2, the right ventricular fractional shortening was significantly lower (P < 0.01) than in Group 1. Coronary artery blood flow was visualized significantly more often (P < 0.03) and tricuspid regurgitation was present more frequently (P < 0.003) in Group 2 than in Group 1. In Group 2, the ductus venosus pulsatility index for veins was significantly higher than in Group 1 (P < 0.01) and the control group (P < 0.01), with no difference in the inferior vena cava pulsatility index for veins.

CONCLUSIONS

Fetuses with retrograde aortic isthmus net blood flow demonstrate a rise in right ventricular afterload and increased pulsatility in ductus venosus blood velocity waveforms.

On-line measurement of the thickness and optical quality of float glass with a sensor based on a diffractive element

An on-line apparatus for accurate measurement of float-glass thickness and edge distortion was built and tested in industrial environments. The intelligent part of the sensor is a diffractive optical element. The theory and construction of the apparatus are described, and data from on-line measurements are presented.

Postoperative nitric oxide therapy in children with congenital heart disease. Can the need be predicted?

The necessity for postoperative inhaled nitric oxide (NO) therapy and predictive factors for that need were retrospectively analysed in 457 paediatric patients at risk of pulmonary hypertensive events following open-heart surgery for congenital heart disease. Inhaled NO was given postoperatively to 46% of the study group and to 23% of all patients undergoing open-heart surgery during the study period. Factors associated with increased need for postoperative NO were age <1 year, Down's syndrome, preoperative pulmonary hypertension and increased pulmonary vascular resistance. Using a multivariate model based on these factors, 73% of the patients who were given NO were identified. Thus, in a setting with unrestricted access to NO therapy, almost half of the patients with cardiac lesions that commonly give rise to postoperative pulmonary hypertension were given postoperative NO. Seventy-three percent of postoperative NO treatment was associated with a relatively small number of pre- and perioperative patient-related risk factors.

Perioperative determinants and outcome of cardiopulmonary arrest in children after heart surgery

OBJECTIVES

To identify perioperative factors associated with postoperative cardiopulmonary arrest (CA) in the pediatric intensive care unit (PICU) in children undergoing cardiovascular surgery, and to report the outcome of cardiopulmonary resuscitation (CPR) in these patients.

METHODS

We reviewed the medical records of all patients under 16 years of age who had undergone cardiovascular surgery and sustained CA in PICU in an urban, tertiary care children's hospital over a 5-year period. We used two control groups of patients who recovered without CA. (1) Sixty-five patients, who were operated under deep hypothermic circulatory arrest (DHCA) during the study period. (2) All patients who underwent repair of congenital heart lesions without DHCA in 1994 (n=278).

RESULTS

Eighty-two children experienced CA during postoperative care in PICU, mainly from cardiovascular causes. Thirty-four (41%) were declared dead without attempted resuscitation, CPR was initiated in 48 (59%). The primary survival rate was 56% and 1 year survival rate was 19%. The incidence of CA was 3.6% for closed heart operations, 4.9% for intra-cardiac surgery without DHCA, and 27% for operations involving DHCA. Thirty-three per cent of patients with CA arrested during the first 24 postoperative h. Preoperative mechanical ventilation (P=0.03), prostaglandin E1 (P=0.001) and inotropic support (P=0.04) were given significantly more frequently to patients who postoperatively required CPR, compared to control groups. Patients in whom CPR was attempted were younger than the 1994 controls (0.4 vs. 1.2 years; P<0.04), had longer mean aortic-cross-clamp times (76 vs. 51 min; P<0.0001) and cardiopulmonary bypass times (124 vs. 85 min; P<0.0002), and required more inotropic support upon leaving the operating room (P<0.0001). Patients who received CPR had significantly longer DHCA times (53 vs. 32 min; P<0.0002) and required more inotropic support than patients in the DHCA control group (P<0.002).

CONCLUSIONS

CA after pediatric cardiac surgery is associated with repair of complex congenital heart anomalies in patients who require preoperative mechanical ventilation and vasoactive agents, prolonged aortic cross-clamp, circulatory arrest; and heavy postoperative inotropic support.

Umbilical artery N-terminal peptide of proatrial natriuretic peptide in hypertensive pregnancies and fetal acidemia during labor

OBJECTIVE

To assess the activity of the human fetal atrial natriuretic peptide system in hypertensive pregnancies with and without signs of increased fetal systemic venous pressure and in pregnancies complicated by fetal acidemia during labor.

METHODS

Umbilical artery plasma N-terminal peptide of proatrial natriuretic peptide concentrations were measured in neonates by radioimmunoassay. The control group consisted of 50 neonates with uncomplicated gestation and labor. In group 1, there were 22 newborns of hypertensive pregnancies. Doppler ultrasonography showed abnormal umbilical artery blood velocity waveform in five cases and normal nonpulsatile umbilical vein blood velocity profile in every case. Group 2 consisted of five newborns of pregnancies complicated by maternal hypertensive disorder. Atrial pulsations in the umbilical vein and retrograde diastolic blood velocity pattern in the umbilical artery were detected in every case. Group 3 was composed of 27 newborns of uncomplicated pregnancies with fetal acidemia (pH 7.10 or less) during labor.

RESULTS

In groups 1-3, N-terminal peptide of proatrial natriuretic peptide concentrations were higher (P <.001) than in the control group. In group 1, neonates with abnormal umbilical artery blood velocity pattern had higher N-terminal peptide of proatrial natriuretic peptide concentrations than neonates with normal umbilical artery Doppler findings (P <.006). N-terminal peptide of proatrial natriuretic peptide concentrations were higher in group 2 (P <.002) than in groups 1 and 3. CONCLUSIONS Maternal hypertensive disorder and fetal acidemia during labor stimulate fetal atrial natriuretic peptide production, which was greatest in fetuses with severe placental insufficiency and signs of congestive heart failure.

Association of severe placental insufficiency and systemic venous pressure rise in the fetus with increased neonatal cardiac troponin T levels

OBJECTIVE

The aim of this study was to test the hypothesis that severe placental insufficiency and a rise in fetal systemic venous pressure are associated with fetal myocardial cell damage, which in turn leads to increased neonatal troponin T levels.

STUDY DESIGN

Sixty-six neonates born after uncomplicated pregnancy and delivery were included in the control group. Study groups 1 and 2 consisted of 32 and 5 neonates, respectively, born to women with hypertensive disorder. In study group 1 the fetal intra-abdominal portion of the umbilical vein showed normal nonpulsatile blood flow pattern in every case. In study group 2 all the fetuses had atrial pulsations in the intraabdominal umbilical vein. After delivery blood samples were collected from the umbilical arteries, and cardiac troponin T concentrations were measured with commercially available enzyme-linked immunosorbent assay kits. A clinically significant troponin T level was set at >/=0.10 ng/mL.

RESULTS

In study group 1 the maternal main uterine arterial blood flow pattern was normal in 30 cases and abnormal in 2 cases. Umbilical artery blood velocity waveforms were normal in 26 fetuses, 4 fetuses had a decreased diastolic blood flow, 1 fetus had an absent diastolic blood flow pattern, and 1 fetus had a retrograde diastolic blood flow pattern. In study group 2 maternal uterine arterial Doppler findings were abnormal in every case, and all the fetuses had retrograde diastolic blood flow pattern in the umbilical artery. Neonatal troponin T levels were <0.10 ng/mL in the control group (0-0.14 ng/mL) and in study group 1 (0-0.16 ng/mL), except for 1 case in each group. Every neonate in study group 2 had a troponin T level >0.10 ng/mL, with the range from 0.11 to 0.35 ng/mL. In study group 2 troponin T concentrations were significantly higher (P <.0001) than in either the control group or study group 1.

CONCLUSION

Neonatal troponin T levels are not clinically significantly increased in normal pregnancies and in pregnancies complicated by maternal hypertensive disorder but with normal fetal umbilical venous return. Neonatal troponin T concentrations are significantly increased in the presence of abnormal umbilical venous return, which indicates myocardial cell damage.

Pharmacokinetics of amrinone in neonates and infants

OBJECTIVE

To evaluate the pharmacokinetics of amrinone and its metabolites in neonates and infants after reconstructive surgery for congenital heart disease.

DESIGN

Prospective study.

SETTING

Pediatric intensive care unit in a university hospital.

PARTICIPANTS

Fifteen neonates aged less than 1 month with transposition of the great arteries and 14 infants aged 2 to 6 months with complete atrioventricular septal defect.

INTERVENTIONS

Amrinone, loading dose of 2 mg/kg, was administered before weaning from cardiopulmonary bypass, followed by a maintenance infusion of 7.5 microg/kg/min.

MEASUREMENTS AND MAIN RESULTS

Blood samples to determine plasma concentrations of amrinone, N-acetylamrinone, and N-glycolylamrinone were drawn before amrinone administration, frequently after the loading dose, every 6 hours during the maintenance infusion, and until 48 hours after the end of the infusion. Amrinone clearance was 2.4 +/- 0.9 mL/kg/min in neonates and 3.2 +/- 1.2 mL/kg/min in infants (p < 0.05). The volume of distribution at steady-state was smaller (p < 0.05) in neonates than in infants. The elimination half-life of amrinone was 10.7 +/- 6.7 hours in neonates and 6.1 +/- 1.4 hours in infants (p < 0.05). There was a linear correlation between the clearance of amrinone and the body surface area (r = 0.67; p < 0.05). The ratio of the plasma concentration of N-acetylamrinone to that of amrinone did not differ between neonates and infants.

CONCLUSIONS

Amrinone is eliminated at a slower rate in neonates than in infants. The rate of acetylation of amrinone appears to be similar; the differences in the elimination capacity of amrinone are mainly due to the immature renal function in neonates.

Utstein style reporting of in-hospital paediatric cardiopulmonary resuscitation

STUDY OBJECTIVE

To report paediatric in-hospital cardiac arrest data according to Utstein style and to determine the effectiveness of cardiopulmonary resuscitation (CPR) in hospitalized children.

DESIGN

Retrospective 5-year case series.

SETTING

Urban, tertiary-care children's hospital.

PARTICIPANTS

All patients who sustained cardiopulmonary arrest.

RESULTS

Altogether 227 patients experienced a cardiopulmonary arrest during the study period, 109 (48.0%) were declared dead without attempted resuscitation, and CPR was initiated in 118 (52.0%). The incidence of cardiac arrest was 0. 7% of all hospital admissions and 5.5% of PICU admissions; the incidence of CPR attempts was 0.4 and 2.5%, respectively. Most of the CPR attempts (64.4%) took place in the PICU and the most frequent aetiology was cardiovascular (71.2%). The 1-year survival rate was 17.8%. Short duration of external CPR was the best prognostic factor associated with survival. With few exceptions, the Paediatric Utstein Style was found to be applicable for reporting retrospective data from in-hospital cardiac arrests in children.

CONCLUSIONS

In-hospital cardiopulmonary resuscitation was shown to be an uncommon event in children; the survival rate was similar to earlier studies.

Measured versus predicted oxygen consumption in children with congenital heart disease

OBJECTIVE

To compare measured and predicted oxygen consumption (VO2) in children with congenital heart disease.

DESIGN

Retrospective study.

SETTING

The cardiac catheterisation laboratory in a university hospital.

PATIENTS

125 children undergoing preoperative cardiac catheterisation.

INTERVENTIONS

VO2 was measured using indirect calorimetry; the predicted values were calculated from regression equations published by Lindahl, Wessel et al, and Lundell et al. Stepwise linear regression and analysis of variance were used to evaluate the influence of age, sex, weight, height, cardiac malformation, and heart failure on the bias and precision of predicted VO2. An artificial neural network was trained and used to produce an estimate of VO2 employing the same variables. The various estimates for VO2 were evaluated by calculating their bias and precision values.

RESULTS

Lindahl's equation produced the highest precision (+/- 42%) of the regression based estimates. The corresponding average bias of the predicted VO2 was 3% (range -66% to 43%). When VO2 was predicted according to regression equations by Wessel and Lundell, the bias and precision were 0% and +/- 44%, and -16% and +/- 51%, respectively. The neural network predicted VO2 from variables included in the regression equations with a bias of 6% and precision +/- 29%; addition of further variables failed to improve this estimate.

CONCLUSIONS

Both regression based and artificial intelligence based techniques were inaccurate for predicting preoperative VO2 in patients with congenital heart disease. Measurement of VO2 is necessary in the preoperative evaluation of these patients.

Detection of lung injury with conventional and neural network-based analysis of continuous data

OBJECTIVE

To test if analysis of pressure and flow waveform patterns with an artificial intelligence neural network could distinguish between normal and injured lungs.

METHODS

Acute lung injury was induced in ten healthy anesthetized, mechanically ventilated dogs with repeated injections of oleic acid, until arterial blood oxyhemoglobin saturation reached 85% breathing room air. Airway pressure, esophageal pressure, airway flow, and arterial and mixed venous saturation signals were stored at 2 min intervals. Hemodynamic and blood gas data were collected every 10 min. Back-propagation neural networks were trained with normalized airway pressure and flow waveforms from normal and fully injured lungs.

RESULTS

The networks scored lung injury on a continuous scale from +1 (normal) to -1 (injured). Network scores unequivocally distinguished between normal and fully injured lungs and suggested a gradual transition from normal to injury pattern. However, the response of the network was slow compared to compliance, resistance and venous admixture.

CONCLUSIONS

Normal and fully injured lungs display distinct flow and pressure waveform patterns which are independent of changes in calculated pulmonary mechanics variables. These patterns can be recognized by a neural network. Further research is needed to determine the full potential of automated pattern recognition for lung monitoring.

Efficacy of cardiopulmonary resuscitation in pulseless paediatric trauma patients

BACKGROUND

A study was designed to determine which paediatric trauma patients with no detectable vital signs are likely to benefit from cardiopulmonary resuscitation (CPR).

METHODS

A 10-year retrospective study of all pulseless patients under 16 years of age with trauma in whom CPR was initiated in a prehospital or in-hospital setting in Southern Finland.

RESULTS

Forty-one patients, 25 male and 16 female, were included in this study. The mean age was 7.8 years (range 0.1-15.9 years). Twenty three patients had blunt injuries and three patients had penetrating injuries. The mean Injury Severity Score was 51 (range 25-75). In 15 patients, the arrest was secondary to smoke inhalation, strangulation or electric shock. Resuscitation was initiated at the scene or en route in 28 patients and in 13 patients at the hospital. Five patients received open-chest CPR and 36 patients closed-chest CPR. Spontaneous circulation was restored in four patients with open-chest CPR and in six patients with closed-chest CPR. Two patients had intact survival and one patient survived with moderate disability. The mechanism of traumatic cardiac arrest, initial cardiac rhythm or location of arrest did not seem to affect outcome of CPR.

CONCLUSIONS

The overall survival rate of paediatric patients with cardiac arrest secondary to trauma is poor. Trauma patients in whom cardiac arrest is caused by respiratory arrest or by thoracoabdominal trauma in the hospital setting may have a chance of survival if a spontaneous circulation is rapidly restored with effective resuscitative measures.

Computer simulation of the scatter plate interferometer by scalar diffraction theory

Detailed computer simulations of the scatter plate interferometer with random scatterers in the scatter plate are performed, for the first time to our knowledge, by use of the scalar diffraction theory in the paraxial domain. It is shown that the computer simulations produce output image patterns of the expected qualitative characteristics. A qualitative comparison of the computed pattern with the experimentally observed pattern is presented. The effects of translation of the scatter plate and distortion and tilting of the test object are also successfully simulated by the computer.