Evaluation of portal venous gas detected by ultrasound examination for diagnosis of necrotising enterocolitis

Point-of-care abdominal ultrasound in pediatric and neonatal intensive care units

A spectrum of critical abdominal pathological conditions that might occur in neonates and children warrants real-time point-of-care abdominal ultrasound (abdominal POCUS) assessment. Abdominal radiographs have limited value with low sensitivity and specificity in many cases and have no value in assessing abdominal organ perfusion and microcirculation (Rehan et al. in Clin Pediatr (Phila) 38(11):637-643, 1999). The advantages of abdominal POCUS include that it is non-invasive, easily available, can provide information in real-time, and can guide therapeutic intervention (such as paracentesis and urinary bladder catheterization), making it a crucial tool for use in pediatric and neonatal abdominal emergencies (Martínez Biarge et al. in J Perinat Med 32(2):190-194, 2004) and (Alexander et al. in Arch Dis Child Fetal Neonatal Ed 106(1):F96-103, 2021).  Conclusion: Abdominal POCUS is a dynamic assessment with many ultrasound markers of gut injury by two dimensions (2-D) and color Doppler (CD) compared to the abdominal X-ray; the current evidence supports the superiority of abdominal POCUS over an abdominal X-ray in emergency situations. However, it should still be considered an adjunct rather than replacing abdominal X-rays due to its limitations and operator constraints (Alexander et al. in Arch Dis Child Fetal Neonatal Ed 106(1):F96-103, 2021). What is Known: • Ultrasound is an important modality for the assessment of abdominal pathologies. What is New: • The evidence supports the superiority of abdominal POCUS over an abdominal X-ray in emergency abdominal situations in the neonatal and pediatric intensive care units.

Neonatal and paediatric point-of-care ultrasound review

Purpose

Point-of-care ultrasound (POCUS) examinations for children and newborns are different from POCUS exams for adults due to dissimilarities in size and body composition, as well as distinct surgical procedures and pathologies in the paediatric patient. This review describes the major paediatric POCUS exams and how to perform them and summarizes the current evidence-based perioperative applications of POCUS in paediatric and neonatal patients.

Method

Literature searches using PubMed and Google Scholar databases for the period from January 2000 to November 2021 that included MeSH headings of [ultrasonography] and [point of care systems] and keywords including "ultrasound" for studies involving children aged 0 to 18 years.

Results

Paediatric and neonatal POCUS exams can evaluate airway, gastric, pulmonary, cardiac, abdominal, vascular, and cerebral systems.

Discussion

POCUS is rapidly expanding in its utility and presence in the perioperative care of paediatric and neonatal patients as their anatomy and pathophysiology are uniquely suited for ultrasound imaging applications that extend beyond the standard adult POCUS exams.

Conclusions

Paediatric POCUS is a powerful adjunct that complements and augments clinical diagnostic evaluation and treatment.

Review of Necrotizing Enterocolitis and Spontaneous Intestinal Perforation Clinical Presentation, Treatment, and Outcomes

The Necrotizing Enterocolitis Surgery Trial (NEST) highlights the importance of distinguishing necrotizing enterocolitis (NEC) from spontaneous intestinal perforation (SIP) when developing surgical treatment plans. Further research is needed to increase the accuracy of this distinction, but even with our current abilities to do this initial laparotomy appears to be optimal for infants with presumed NEC. The preferred initial operation for those with SIP is more equivocal. Rates of NEC are likely decreasing slowly, whereas those with SIP are not. New imaging modalities, especially ultrasound, are becoming more useful but require more detailed investigation. Understanding the mechanisms causing these two conditions remains of paramount importance.

A new intestinal ultrasound integrated approach for the management of neonatal gut injury

Clinical management of gut injury has been a challenge to the clinician since the first description of necrotizing enterocolitis (NEC) about 50 years ago, and it is still poorly defined. Most of the diagnostic markers are non-specific, and there is no consensus yet on a reliable gold standard for diagnosis. This report describes our approach to integrating point of care intestinal ultrasound (IUS) as the primary radiological assessment modality with other clinical and biochemical markers.

CONCLUSIONS

This is the first clinical guideline integrating point of care IUS as a routine assessment of the gut injury. This integrated algorithm improves the quality of care of the gut injury, provides a more accurate diagnosis of NEC, and differentiates other categories of gut injury.

WHAT IS KNOWN

• Necrotizing enterocolitis is a poorly defined disease, and the routine assessment relying on AXR does not differentiate NEC from other categories of gut injury.

WHAT IS NEW

• Integrating point of care IUS with the routine clinical assessment of gut injury enables the gut injury to be classified according to the triggering factors and severity; this helps target the appropriate management.

Imaging for Diagnosis and Assessment of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is inflammatory bowel necrosis of preterm and critically ill infants. The disease is seen in 6-10% of preterm infants who weigh less than 1500 g at birth and carries considerable morbidity, mortality, and healthcare cost burden. Efforts focused on timely mitigation remain restricted due to challenges in early diagnosis as clinical features, and available laboratory tests remain nonspecific until late in the disease. There is renewed interest in the radiological and sonographic assessment of intestinal diseases due to technological advances making them safe, cost-efficient, and supporting Web-based transmission of images, thereby reducing time to diagnosis by disease experts. Most of our experience has been with plain abdominal radiography, which shows characteristic features such as pneumatosis intestinalis in up to 50-60% of patients. Many patients with advanced disease may also show features such as portal venous gas and pneumoperitoneum. Unfortunately, these features are not seen consistently in patients with early, treatable conditions, and hence, there has been an unfulfilled need for additional imaging modalities. In recent years, abdominal ultrasound (AUS) has emerged as a readily available, noninvasive imaging tool that may be a valuable adjunct to plain radiographs for evaluating NEC. AUS can allow real-time assessment of vascular perfusion, bowel wall thickness, with higher sensitivity in detecting pneumatosis, altered peristalsis, and characteristics of the peritoneal fluid. Several other modalities, such as contrast-enhanced ultrasound (CEUS), magnetic resonance imaging (MRI), and near-infrared spectroscopy (NIRS), are also emerging. In this article, we have reviewed the available imaging options for NEC evaluation.

Feasibility and acceptability of a diagnostic randomized clinical trial of bowel ultrasound in infants with suspected necrotizing enterocolitis

We conducted a pilot diagnostic randomized clinical trial (RCT) to examine the feasibility, acceptability, and preliminary outcomes of adding bowel ultrasound (BUS) to the diagnostic evaluation for necrotizing enterocolitis (NEC). Infants ≤ 32 weeks' gestational age with NEC concern were randomized to undergo abdominal X-ray (AXR) or AXR + BUS. The primary outcome was study feasibility. Secondary outcomes included rates of NEC diagnosis and duration of treatment with bowel rest and antibiotics. A total of 56 infants were enrolled; 16 developed NEC concern and were randomized. Rates of recruitment (56/82 = 68%), retention (16/16 = 100%), and protocol compliance (126/127 = 99%) met pre-specified thresholds for feasibility. No significant differences in rates of NEC diagnosis were found between the two groups. Durations of bowel rest and antibiotic treatment were also similar.   Conclusion: Our study supports the feasibility of conducting a definitive diagnostic RCT to establish safety and efficacy of BUS for NEC.   Clinical trial registration: The study was registered at https://clinicaltrials.gov (NCT03963011). What is Known: • Bowel ultrasound (BUS) is increasingly being utilized as an adjunct to abdominal radiographs in evaluating for necrotizing enterocolitis (NEC). • The impact of BUS on patient outcomes is unknown. What is New: • A diagnostic randomized controlled trial study design to determine safety and effectiveness of adding BUS to NEC evaluation is feasible and acceptable.

Doppler ultrasound assessment of splanchnic perfusion and heart rate for the detection of necrotizing enterocolitis

PURPOSE

Monitoring disease progression is crucial to improve the outcome of necrotizing enterocolitis (NEC). A previous study indicates that intestinal wall flow velocity was reduced in NEC pups from the initial stages of the disease. This study aims to investigate whether splanchnic perfusion via the superior mesenteric artery (SMA) (i) is altered during NEC development and (ii) can be used as a monitoring tool to assess disease progression.

METHODS

NEC was induced in C57BL/6 mice via gavage feeding of formula, hypoxia, and oral lipopolysaccharide, from postnatal day 5 (P5) to P9 (AUP: 32,238). Breastfed littermates served as controls. Doppler ultrasound (U/S) of bowel loops was performed daily. Intestinal wall perfusion was calculated as average flow velocity (mm/s) of multiple abdominal regions. Groups were compared using one-way ANOVA.

RESULTS

The SMA flow velocity was not altered during the initial stage of NEC development, but become significantly reduced at P8 when the intestinal disease was more advanced. These changes occurred concomitantly with an increase in heart rate.

CONCLUSIONS

NEC is associated with intestinal hypo-perfusion at the periphery and flow in the SMA is reduced during the later stages of disease indicating the presence of intestinal epithelium damage. This study contributes to understanding NEC pathophysiology and illustrates the value of Doppler U/S in monitoring disease progression.

Implementation of bowel ultrasound practice for the diagnosis and management of necrotising enterocolitis

Necrotising enterocolitis (NEC) is a serious inflammatory bowel disease of prematurity with potentially devastating complications and remains a leading cause of morbidity and mortality among premature infants. In recent years, there has been accumulating data regarding benefits of using bowel ultrasound (BUS) in the diagnosis and management of NEC. Despite this, adoption of robust BUS programmes into clinical practice has been slow. As BUS is a relatively new technique, many barriers to implementation exist, namely lack of education and training for sonographers and radiologists, low case volume and unfamiliarity by clinicians regarding how to use the information provided. The aim of this manuscript is to provide a framework and a roadmap for units to implement BUS in day-to-day practice for NEC diagnosis and management.

International evidence-based guidelines on Point of Care Ultrasound (POCUS) for critically ill neonates and children issued by the POCUS Working Group of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC)

BACKGROUND

Point-of-care ultrasound (POCUS) is nowadays an essential tool in critical care. Its role seems more important in neonates and children where other monitoring techniques may be unavailable. POCUS Working Group of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC) aimed to provide evidence-based clinical guidelines for the use of POCUS in critically ill neonates and children.

METHODS

Creation of an international Euro-American panel of paediatric and neonatal intensivists expert in POCUS and systematic review of relevant literature. A literature search was performed, and the level of evidence was assessed according to a GRADE method. Recommendations were developed through discussions managed following a Quaker-based consensus technique and evaluating appropriateness using a modified blind RAND/UCLA voting method. AGREE statement was followed to prepare this document.

RESULTS

Panellists agreed on 39 out of 41 recommendations for the use of cardiac, lung, vascular, cerebral and abdominal POCUS in critically ill neonates and children. Recommendations were mostly (28 out of 39) based on moderate quality of evidence (B and C).

CONCLUSIONS

Evidence-based guidelines for the use of POCUS in critically ill neonates and children are now available. They will be useful to optimise the use of POCUS, training programs and further research, which are urgently needed given the weak quality of evidence available.

Portal Venous Gas on Point-of-Care Ultrasound in a Case of Cecal Ischemia

BACKGROUND

Portal venous gas has mainly been studied in pediatrics and seen in cases of necrotizing enterocolitis. It is a rare finding in adults and is typically associated with underlying intestinal ischemia or other malignant intra-abdominal pathology. Portal venous gas is seen more readily on ultrasound compared to radiographs in both pediatric and adult patients. Findings include lucencies extending to the periphery of the liver, echogenic bubbles flowing centrifugally throughout the portal venous system, and bidirectional spikes interrupting the monophasic portal venous waveform on spectral analysis.

CASE REPORT

We present a case of a 36-year-old female who presented with abdominal pain. She had findings consistent with portal venous gas on point-of-care ultrasound, prompting computed tomography of her abdomen and surgical consultation. She was ultimately found to have cecal ischemia from cecal volvulus, had surgical resection and anastomosis, and was able to be discharged from the hospital following recovery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: With the ever-increasing use of point-of-care ultrasound, emergency physicians should be aware of the findings consistent with portal venous gas as well as its implications. Emergency physicians should know portal venous gas is associated with intestinal ischemia and other malignant pathologies and should prompt more advanced imaging or surgical consultation when observed. Emergency physicians should also understand the distinctions between portal venous gas and pneumobilia found on point-of-care ultrasound, given that portal venous gas is typically a malignant finding and pneumobilia is most frequently benign.

Abdominal ultrasound should become part of standard care for early diagnosis and management of necrotising enterocolitis: a narrative review

Necrotising enterocolitis (NEC) is a leading cause of death and disability in preterm newborns. Early diagnosis through non-invasive investigations is a crucial strategy that can significantly improve outcomes. Hence, this review gives particular attention to the emerging role of abdominal ultrasound (AUS) in the early diagnosis of NEC, its performance against abdominal radiograph and the benefits of AUS use in daily practice. AUS has been used in the diagnosis and management of NEC for a couple of decades. However, its first-line use has been minimal, despite growing evidence demonstrating AUS can be a critical tool in the early diagnosis and management of NEC. In 2018, the NEC group of the International Neonatal Consortium recommended using AUS to detect pneumatosis and/or portal air in preterm NEC as part of the 'Two out of three' model. To facilitate widespread adoption, and future improvement in practice and outcomes, collaboration between neonatologists, surgeons and radiologists is needed to generate standard operating procedures and indications for use for AUS. The pace and scale of the benefit generated by use of AUS can be amplified through use of computer-aided detection and artificial intelligence.

Current status of laboratory and imaging diagnosis of neonatal necrotizing enterocolitis

Necrotizing enterocolitis continues to be a devastating disease process for very low birth weight infants in Neonatal Intensive Care Units. The aetiology and pathogenesis of necrotizing enterocolitis are not definitively understood. It is known that necrotizing enterocolitis is secondary to a complex interaction of multiple factors that results in mucosal damage, which leads to intestinal ischemia and necrosis. Advances in neonatal care, including resuscitation and ventilation support technology, have seen increased survival rates among premature neonates and a concomitant detection in the incidence of this intestinal disease.Diagnosis can be difficult, and identifying infants at the onset of disease remains a challenge. Early diagnosis, which relies on imaging findings, and initiation of prompt therapy are essential to limit morbidity and mortality. Moreover, early management is critical and life-saving.This review summarizes what is known on the laboratory and instrumental diagnostic strategies needed to improve neonatal outcomes and, possibily, to prevent the onset of an overt necrotizing enterocolitis.

Value of abdominal ultrasound in management of necrotizing enterocolitis: a systematic review and meta-analysis

PURPOSE

Necrotizing enterocolitis (NEC) remains a life-threatening disease among infants in the NICU. Early diagnosis and careful monitoring are essential to improve outcomes. Abdominal ultrasound (AUS) seems a promising addition to current diagnostic modalities, but its clinical utility is uncertain. The aim of this study was to identify AUS features associated with definite NEC (i.e. Bell stage ≥ II), failed medical treatment, surgery, and death.

METHODS

Embase, MEDLINE, Web of Science and CINAHL databases were searched for studies that addressed any NEC-related AUS feature in relation to any of the four outcomes. After critical appraisal of relevant study methods, meta-analyses were conducted using a random-effect model.

RESULTS

15 out of 1215 studies were included. All AUS features had sensitivities below 70% and specificities largely above 80% for diagnosing definite NEC; several AUS features were significantly associated with failed medical treatment and surgery. Substantial heterogeneity, poor reporting quality and uncertain risk of bias were found.

CONCLUSIONS

While clear associations of AUS features with failed medical treatment exist and AUS may detect definite NEC, substantial heterogeneity, poor reporting quality and an uncertain risk of bias impair the use of AUS for clinical decision making. A prospective, well-designed validation study is needed.

The role of imaging in the management of necrotising enterocolitis: a multispecialist survey and a review of the literature

Objectives

To investigate current practices and perceptions of imaging in necrotising enterocolitis (NEC) according to involved specialists, put them in the context of current literature, and identify needs for further investigation.

Methods

Two hundred two neonatologists, paediatric surgeons, and radiologists answered a web-based questionnaire about imaging in NEC at their hospitals. The results were descriptively analysed, using proportion estimates with 95% confidence intervals.

Results

There was over 90% agreement on the value of imaging for confirmation of the diagnosis, surveillance, and guidance in decisions on surgery as well as on abdominal radiography as the first-choice modality and the most important radiographic signs. More variation was observed regarding some indications for surgery and the use of some ultrasonographic signs. Fifty-eight per cent stated that ultrasound was used for NEC at their hospital. Examination frequency, often once daily or more but with considerable variations, and projections used in AR were usually decided individually rather than according to fixed schedules. Predicting the need of surgery was regarded more important than formal staging.

Conclusion

Despite great agreement on the purposes of imaging in NEC and the most important radiographic signs of the disease, there was considerable diversity in routines, especially regarding examination frequency and the use of ultrasound. Apart from continuing validation of ultrasound, important objectives for future studies include definition of the supplementary roles of both imaging modalities in relation to other diagnostic parameters and evaluation of various imaging routines in relation to timing of surgery, complications, and mortality rate.

Key Points

• Imaging is an indispensable tool in the management of necrotising enterocolitis

• Predicting the need of surgery is regarded more important than formal staging

• There is great consensus on important signs of NEC on abdominal radiography

• There is more uncertainty regarding the role of ultrasound

• Individualised management is preferred over standardised diagnostic algorithms

Electronic supplementary material

The online version of this article (10.1007/s00330-018-5362-x) contains supplementary material, which is available to authorized users.

Excessive Bright Echoes Sign for Hypertrophic Pyloric Stenosis Suggest the Diagnosis: Gastric Pneumatosis and Portal Venous Gas in Infants Suggest HPS

We describe a new finding, the "excessive bright echoes" sign, for the diagnosis of hypertrophic pyloric stenosis (HPS). Portal venous gas and gastric wall pneumatosis were noted in 4 vomiting infants proven to have HPS. Portal venous gas can be concerning for ischemic bowel. Gastric wall pneumatosis can be seen in association with necrotizing enterocolitis and has been associated with increased gastric pressure from severe, usually proximal, bowel obstruction. Our HPS cases had prominent bright punctate echoes on sonography of the liver, portal vein lumen, and gastric wall. Knowledge of this excessive bright echoes sign suggests the need for sonography of the antropyloric area. One should consider HPS as a differential diagnostic possibility when the combination of bright echoes within the liver parenchyma, consistent with portal venous gas, and bright echoes in the gastric wall, consistent with gastric pneumatosis, are seen.

Doppler ultrasound assessment of the splanchnic circulation in preterms with neonatal sepsis at risk for necrotizing enterocolitis

OBJECTIVE

To evaluate the role of Doppler ultrasonography in the assessment of splanchnic circulation's hemodynamic changes in septic preterms at risk of necrotizing enterocolitis.

METHODS

A total of 51 septic preterms were divided into two groups: 25 preterms with clinical signs of necrotizing enterocolitis (NEC) and 26 preterms with no clinical signs of NEC. Both groups were assessed with Doppler ultrasonography of the celiac and superior mesenteric arteries, and each septic preterm's peak systolic velocity (PSV), end-diastolic velocity (EDV), resistivity index (RI), and pulsatility index (PI) was calculated and recorded.

RESULTS

These included a statistically significant lower PSV (p: 0.001) and a lower EDV (p: 0.001) in the superior mesenteric artery in the septic group with clinical signs of NEC in comparison with the septic group with no clinical signs of NEC. A statistically significant (p < 0.001) higher PSV celiac (CA)/PSV superior mesenteric (SMA) ratio was found for the group of septic preterms with clinical signs of NEC when compared to the other group.

CONCLUSION

The study results showed that Doppler ultrasonography of the splanchnic circulation can be a tool for the early identification of NEC cases among septic preterms.

Atypical presentation of acute fulminant neonatal necrotising enterocolitis: diagnostic superiority of sonographic evaluation over plain radiography of abdomen

A female preterm infant was born to a non-consanguineous couple at 35 weeks of gestation. On day 8 of life, while on full feeds, she developed prolonged apnoea and bradycardia, requiring respiratory support. Her abdomen was soft with unremarkable serial abdominal X-rays. Her septic screen was negative. Metabolic acidosis was worsening despite treatment. Echocardiography showed evidence of high pulmonary pressures. With further deterioration, an ultrasound scan of the abdomen was requested in view of the rising suspicion of abdominal pathology in the absence of sepsis and metabolic disorders. Mural oedema, pneumatosis and portal venous gas, consistent with diagnosis of necrotising enterocolitis, were noted in the ultrasound images. An emergency laparotomy showed extensive small bowel necrosis. Despite maximal medical support, the infant died. This case highlights the importance of imaging using an ultrasound scanner in the diagnosis of necrotising enterocolitis in preterm infants having intractable metabolic acidosis, subtle abdominal signs and unremarkable abdominal X-rays.

Complementory Value of Sonography in Early Evaluation of Necrotizing Enterocolitis

Background

Despite the widespread use of plain films to detect necrotizing enterocolitis (NEC), it is considered a time-consuming method, which exposes patients to radiation. We aimed to assess changes in ultrasonographic variables and to compare sonograhy and chest radiography in detecting early stages of NEC in suspected premature infants.

Material/Methods

This case-control study was carried out in the years 2012–2013. We enrolled 67 premature neonates using a simple sampling method and divided them into the study and control groups. All patients underwent plain abdominal radiography, gray-scale and color Doppler sonography.

Results

34 and 33 neonates were assigned to the study and control groups. No significant gender differences were found between the two groups (P=0.549). The mean bowel wall thickness ranged from 1.2 to 3.2 mm in the control group (132 abdominal quadrants) and 1–3.3 mm in the study group (136 abdominal quadrants, P=0.502). Intra-mural echogenic dots were seen in one neonate in the study group in favour of pneumatosis intestinalis. The mean ±SD bowel wall perfusion in the study and control groups were 3.117±0.975 and 2.878±0.538 dots or lines/cm², respectively (P=0.218). One neonate in the study group showed internal echoes within the mild amount of free fluid. Twelve neonates in the control group had minimal amounts of intra-abdominal free fluid.

Conclusions

The two groups differed regarding bowel wall thickness, echogenicity, and perfusion in sonograhy and color Doppler evaluation. Although those differences were not statistically significant, considering the time-consuming nature of abdominal X-ray, the use of sonograhy and color Doppler can improve diagnosis and treatment of NEC as a triage method.

Ultrasound to diagnose spontaneous intestinal perforation in infants weighing ⩽ 1000 g at birth

OBJECTIVE

To evaluate the usefulness of abdominal ultrasound in infants with gasless abdomen radiographically suspected to have spontaneous intestinal perforation (SIP).

STUDY DESIGN

This was a retrospective analysis of data from our neonatal database including infants with birth weight ⩽ 1000 g with suspicion of SIP, for the period January 2000 to May 2012.

RESULT

Four hundred and ninety-six infants weighing ⩽ 1000 g were identified. There were 68 infants with suspicion for SIP, 11 with pneumoperitoneum and 57 with gasless abdomen on X-rays. Ultrasound was performed in 55 of 57 infants with gasless abdomen, 10 with SIP and 45 nonperforated. Echogenic free fluid (EFF) was present in 70% of patients with SIP and 11% of nonperforated patients (P<0.001). When performed within 2 days of surgical diagnosis, EFF had 100% sensitivity and 89% specificity, with 58% positive predictive value and 100% negative predictive value.

CONCLUSION

These data suggest that abdominal ultrasound may be useful for the diagnosis of SIP in infants with birth weight ⩽ 1000 g presenting with gasless abdomen.

Prognostic value of abdominal sonography in necrotizing enterocolitis of premature infants born before 33 weeks gestational age

OBJECTIVE

The purpose of this study was to assess the prognostic value of abdominal sonography in necrotizing enterocolitis (NEC) in preterm infants with a gestational age less than 33 weeks of gestation, using surgery and/or death as the primary outcome and stenosis as the secondary outcome.

METHODS

A retrospective study of 95 premature infants (mean gestational age: 28.6 weeks), presenting with NEC between January 2009 and November 2011 and who underwent plain abdominal radiography and sonography, was performed. In uni- and multivariate analyses, radiographic and sonographic findings were correlated with complications ('surgery and/or death' and 'stenosis').

RESULTS

Sonographic findings of free intraperitoneal air (odd ratio [OR]=8.0; IC, 1.4-44.2), free abdominal fluid (OR 3.5; IC 1.3-9.4), portal venous gas (OR 3.9; IC, 1.2-12.9), and bowel wall thickening (OR 2.8; IC,1.1-7.2) were significantly associated with surgery and/or death. Intramural gas was significantly correlated (OR=11.8; IC, 1.5-95.8) with intestinal stenosis following NEC. None of the radiographic findings were associated with complications.

CONCLUSION

Abdominal sonography is a reliable tool for the prognostic assessment of NEC in preterm infants.

A prospective comparison of intestinal sonography and abdominal radiographs in a neonatal intensive care unit

BACKGROUND

No study reported in the literature comprehensively compares findings on neonatal abdominal radiographs with sonography.

OBJECTIVE

To compare the findings on abdominal radiographs and sonograms in infants in intensive care, to better understand how the various intestinal gas patterns on radiographs relate to the spectrum of appearances on sonography and, second, to evaluate the ability of sonography to differentiate necrotizing enterocolitis from other intestinal pathology.

MATERIALS AND METHODS

We prospectively evaluated sonograms and radiographs, blinded to the other modality and to clinical information. Patients' charts were reviewed by a third blinded reader and used as a reference standard for diagnosis. We made associations between sonographic findings, radiographic intestinal gas patterns and clinical diagnoses.

RESULTS

We included 75 infants with gestational ages between 23 weeks and 41 weeks. Sonographic abnormalities were present in infants with all radiographic intestinal gas patterns, including normal patterns. We only saw absent intestinal perfusion and fluid collections on sonography (suggesting intestinal necrosis and sealed perforation) in infants with intestinal dilatation with elongation on radiographs. Separation of intestinal loops on radiographs was most commonly caused by reasons other than intestinal wall thickening. Increased intestinal echogenicity or free fluid with echoes on sonography correlated with a diagnosis of necrotizing enterocolitis, whereas anechoic free fluid correlated with absence of necrotizing enterocolitis.

CONCLUSION

Sonography is complementary to radiographs in infants with suspected intestinal pathology, with a spectrum of appearances seen on each modality. Some sonographic findings either strongly suggest necrotizing enterocolitis or supply evidence against this diagnosis.

Usefulness of abdominal ultrasound in diagnosing necrotising enterocolitis

Necrotising enterocolitis is a serious disorder in preterm infants with a mortality of up to 60%. Therefore, early and precise diagnosis and rapid initiation of proper treatment are essential. Clinically suspected diagnosis is usually confirmed by typical findings on plain abdominal radiograph, for example, pneumatosis intestinalis, portal venous gas and, in case of intestinal perforation, pneumoperitoneum. Recently, there has been growing evidence that with real-time ultrasound, intramural air and portal gas can be better detected than with x-ray. Furthermore, ultrasound is able to assess the bowel wall directly and detect bowel wall thickening or thinning, reduced peristalsis or disturbed bowel wall perfusion. Intra-abdominal fluid, both intraluminal or extraluminal is also visible. However, data regarding the diagnostic validity and prognostic value of abdominal ultrasound are limited and often focused on a single finding rather than a combination of them. Additionally, until now, ultrasound findings seem to have little influence on therapeutic decisions. Therefore, the value of abdominal ultrasound in the diagnosis of necrotising enterocolitis has to be determined by further studies until its use can be generally recommended.

Sonographic detection of transient gas in the portal vein in an infant following abdominal surgery: a possible sign of adhesive small bowel obstruction

We present a case of sonographically detected transient gas in the portal vein in a 4.5-month-old infant who had a history of two consecutive jejunectomies due to jejunal stenoses and was admitted to our hospital with clinical and laboratory findings consistent with a subacute small bowel obstruction and dehydration. Sonography excluded other pathologies and the patient was treated conservatively with success. The presence of gas in the portal vein could be a sign of an underlying mechanical obstacle, as another episode of small bowel obstruction 1 month later required surgical treatment of adhesive intestinal obstruction.

Does abdominal sonography provide additional information over abdominal plain radiography for diagnosis of necrotizing enterocolitis in neonates?

PURPOSE

To explore whether addition of abdominal sonography (AUS) to plain radiography is helpful in the management of premature newborns with necrotizing enterocolitis (NEC).

METHODS

This study is a prospective analysis of 93 premature neonates with NEC who were followed-up in our neonatal intensive care unit between October 2007 and April 2009.

RESULTS

Patients were classified into two groups; group I with suspected NEC (stage I) (n = 54) and group II with definite NEC (stage ≥II) (n = 39). Pneumatosis intestinalis (PI) (n = 29), free air (n = 9), and portal venous gas (PVG) (n = 1) were observed in group II on plain radiography. In the same group, echoic free fluid (EFF) (n = 9), PVG (n = 6), PI (n = 5), and focal fluid collection (n = 3) were the most prominent sonographic findings. In patients with intestinal perforation, whereas EFF and bowel wall thinning were observed on AUS, free air was not detected on plain radiography as a sign of intestinal perforation.

CONCLUSION

Our results suggest AUS to be superior to plain radiography on early detection of intestinal perforation by demonstrating PVG and EFF collection. Therefore, it may be life-saving by directing the surgeon to perform surgical intervention in the case of clinical deterioration in the course of NEC.