Establishing a pediatric interventional radiology inpatient consult service.

OBJECTIVE: To delineate pediatric interventional radiology (IR) inpatient consult growth and resulting collections after implementation of a pediatric IR consult service. METHODS: An inpatient IR consult process was created at a single academic children's hospital in October 2019. IR consult note templates were created in Epic (Epic Systems Corporation, Verona, Wisconsin) and utilized by 4 IR physicians. Automatic charge generation was linked to differing levels of evaluation and management (E&M) service relating to current procedural terminology (CPT) inpatient consult codes 99251-99255. The children's hospital informatics division identified IR consult notes entered from the implementation of the consult service: October 2019 to January 2022. The university radiology department billing office provided IR service E&M charge, payment, and relative value units (RVU) information during this study period. A chart review was performed to determine the IR procedure conversion rate. Mann-Whitney and a two-sample t-test statistical analyses compared use of the 25-modifier, monthly consult growth and monthly payment growth. P-value < 0.05 was considered statistically significant.  RESULTS: Within this 27-month period, a total of 2153 inpatient IR consults were performed during 1757 Epic hospital encounters; monthly consult peak was reached 5 months into the study period. Consult level breakdown by CPT codes: 99251-8.7%, 99252-81.7%, and 99253-8.8%. 69.7% of IR consults had consult-specific billing with payments in 96.4% resulting in $143,976 new revenue. From 2020 to 2021, IR consult volume trended upward by 13.4% (P =0.069), and consult-specific payments increased by 84.1% (P<0.001). IR consult procedure conversion rate was 96.5%. CONCLUSION: An inpatient pediatric IR consult service was quickly established and maintained by four physicians over a 27-month study period. Annual IR consult volume trended upward and consult-specific payments increased, resulting in previously uncaptured IR service revenue.

The effects of active classroom breaks on moderate to vigorous physical activity, behaviour and performance in a Northern NSW primary school: A quasi-experimental study.

ISSUE ADDRESSED: Approximately 77% of NSW children aged 5 to 15 years do not meet physical activity guidelines and many spend a considerable amount of time sitting. Active breaks at primary school are feasible, may increase daily moderate to vigorous physical activity (MVPA) and decrease off-task behaviour without adversely affecting cognitive function and learning. METHODS: In this quasi-experimental study, 101 primary school children in six intervention classrooms participated in three 10-minute active breaks per day for six-weeks during class time, while five control classrooms were run as usual (n = 89). Physical activity levels were measured using wrist-worn Actigraph wGT3X-BT accelerometers and analysed using a random forest model. Students' off-task behaviour, wellbeing, cognitive function and maths performance were also measured. School staff completed a brief feedback survey. RESULTS: Children in the intervention group engaged in 15.4 and 10.9 minutes more MVPA per day at 3 and 6 weeks respectively (P < .001). Participation significantly increased the proportion of children who met the Australian 24-Hour Movement Guidelines (P < .001). At pre, middle and end of intervention, 44.4%, 60.8% and 55.1% of intervention children and 46.5%, 45.9% and 45.8% of controls met the guidelines. Significantly fewer students engaged in off-task behaviour in the intervention classes at mid and final weeks of intervention (-1.4 students, P = .003). No significant intervention effects were found for wellbeing, cognitive and maths performance. CONCLUSIONS: Active classroom breaks are an effective way to increase physical activity among primary school children while reducing off-task classroom behaviour. SO WHAT?: Primary school students' health would benefit from active breaks with no detrimental effects on wellbeing, maths and cognitive performance.

Efficacy of standardizing fibrinolytic therapy for parapneumonic effusion.

BACKGROUND: While chest tube placement with pleural fibrinolytic medication is the established treatment of pediatric empyema, treatment failure is reported in up to 20% of these children. OBJECTIVE: Standardizing fibrinolytic administration among interventional radiology (IR) physicians to improve patient outcomes in pediatric parapneumonic effusion. MATERIALS AND METHODS: We introduced a hospital-wide clinical pathway for parapneumonic effusion (1-2 mg tissue plasminogen activator [tPA] twice daily based on pleural US grade); we then collected prospective data for IR treatment May 2017 through February 2020. These data included demographics, co-morbidities, pediatric intensive care unit (PICU) admission, pleural US grade, culture results, daily tPA dose average, twice-daily dose days, skipped dose days, pleural therapy days, need for chest CT/a second IR procedure/surgical drainage, and length of stay. We compared the prospective data to historical controls with IR treatment from January 2013 to April 2017. RESULTS: Sixty-three children and young adults were treated after clinical pathway implementation. IR referrals increased (P = 0.02) and included higher co-morbidities (P = 0.005) and more PICU patients (P = 0.05). Mean doses per day increased from 1.5 to 1.9 (P < 0.001), twice-daily dose days increased from 38% to 79% (P < 0.001) and median pleural therapy days decreased from 3.5 days to 2.5 days (P = 0.001). No IR patients needed surgical intervention. No statistical differences were observed for gender/age/weight, US grade, need for a second IR procedure or length of stay. US grade correlated with greater positive cultures, need for chest CT/second IR procedure, and pleural therapy days. CONCLUSION: Interventional radiology physician standardization improved on a clinical pathway for fibrinolysis of parapneumonic effusion. Despite higher patient complexity, pleural therapy duration decreased. There were no chest tube failures needing surgical drainage.

Recanalization of Chronic Portal Vein Occlusion in Pediatric Liver Transplant Patients.

PURPOSE: To evaluate technical and clinical success and report long-term outcomes of portal vein (PV) recanalization in pediatric orthotopic liver transplant (OLT) patients with chronic PV occlusion. MATERIALS AND METHODS: This is a retrospective review of 15 OLT patients (5 males) with chronic PV occlusion who underwent PV recanalization (33 procedures) between October 2011 and February 2018. Median age was 4.5 years (range, 1-16 years); median weight was 16.6 kg (range, 11.5-57.3 kg). Median time interval from OLT to first intervention was 3.25 years (range, 0.6-15.7 years). Clinical presentations included hypersplenism (n = 12), gastrointestinal bleeding (n = 9), and ascites (n = 3). One patient had incidental diagnosis of PV occlusion. Primary, primary-assisted, and secondary patency at 3, 6, 12, and 24 months were evaluated. RESULTS: Technically successful PV recanalization and reduction of PV pressure gradient to ≤ 5 mm Hg was performed in 13/15 patients (87%). Ten of 15 (67%) patients had successful recanalization with the first attempt. Clinical success, defined as improvement in signs and symptoms of portal hypertension, was achieved in 12/13 (92%) patients. Five of 33 (15%) major complications (Society of Interventional Radiology class C), including perisplenic hematoma (n = 2), hemoperitoneum (n = 2), and hepatic artery pseudo aneurysm (n = 1), were managed with pain medication and blood product replacement. Median follow-up was 22 months (range, 1-77 months). Median primary patency was 5 months. Primary patency at 3, 6, 12, and 24 months was 53.8%, 46.2%, 38.5%, and 30.8%, respectively. Primary-assisted patency was 84.6%, 76.9%, 53.8%, and 46.2%, respectively. Secondary patency was 92.3%, 84.6%, 53.8%, and 46.2%, respectively. CONCLUSIONS: PV recanalization is a safe and effective minimally invasive option in the management of chronic PV occlusion after pediatric OLT.

Pediatric percutaneous renal biopsies: comparison of complications between real-time ultrasound guidance and pre-procedure ultrasound-aided skin-marking techniques.

BACKGROUND: Percutaneous renal biopsy is a commonly performed procedure that guides decision-making for children with renal disease. OBJECTIVE: To compare complications from renal biopsies using real-time ultrasound (US) guidance versus pre-procedure US-aided skin-marking in children. MATERIALS AND METHODS: We conducted a priori power analysis using a risk-adjusted model, which indicated we needed a sample size of 643-714 procedures (effect size: 0.8). Then we retrospectively identified consecutive patients who underwent a percutaneous renal biopsy from Jan. 1, 2012, to Dec. 31, 2016. We categorized complications according to the Society of Interventional Radiology (SIR) criteria and compared rates using the Fisher exact test. We analyzed complication predictors using multivariate regression. RESULTS: The study consisted of 701 percutaneous renal biopsies in 553 patients: 313 used real-time US guidance and 388 used pre-procedure US-aided skin-marking. Among the 254/701 (36%) complications, 56/313 (18%) resulted from real-time US guidance and 198/388 (51%) from pre-procedure US-aided skin-marking (P<0.001). In the US real-time guidance group, 39/56 (70%) complications were SIR A, 8/56 (14%) SIR B, 6/56 (11%) SIR C and 3/56 (5%) SIR D. Among the pre-procedure US-aided skin-marking group, 139/198 (70%) complications were SIR A, 47/198 (24%) SIR B, 11/198 (6%) SIR C and 1/198 (1%) SIR D. Complications between the two groups were significantly different regarding SIR A (P<0.001) and SIR B complications (P<0.001) but not major complications. Multivariate regression demonstrated that complications were higher using US-aided pre-procedure skin-marking (odds ratio [OR]=6.30; 95% confidence interval [CI]=3.86, 10.27) than with US real-time guidance. CONCLUSION: Children and young adults who underwent real-time US-guided percutaneous renal biopsies had significantly fewer minor complications, including those requiring follow-up medical care, compared to those who underwent percutaneous renal biopsies with pre-procedure US-aided skin-marking. No difference was detected in the incidence of major complications.

Equivalent success and complication rates of tunneled common femoral venous catheter placed in the interventional suite vs. at patient bedside.

BACKGROUND: Femoral tunneled central line placement in the pediatric population offers an alternative means for intravenous (IV) access, but there is concern for higher complication and infection rates when placed at bedside. OBJECTIVE: To describe the complications and infection outcomes of primary femoral tunneled central venous catheter placement in the interventional radiology suite compared to the portable bedside location at a single tertiary pediatric institution. MATERIALS AND METHODS: We conducted a retrospective review comparing interventional radiology suites vs. bedside primary tunneled common femoral vein central line placement (January 2014 to December 2015). We identified 244 primary femoral placements in pediatric patients, ages 1 day to 18 years, using our electronic medical record and collected into a Research Electronic Data Capture. We compared categorical variables using the Fisher exact test. We compared continuous variables using the Wilcoxon rank test. RESULTS: In total, 2,375 pediatric patients received peripherally inserted and central lines; 244 of these were primary femoral tunneled central venous catheters (in 140 boys and 104 girls). In 140 children (mean age: 206 days), lines were inserted in the interventional radiology (IR) suite (technical success of 100%), with 14 (10.0%) complications including infection (n=7), malposition (n=2), bleeding (n=0), thrombosis (n=1) and line occlusion (n=4). The infection rate was 2.1 per 1,000 line days. In 104 children (mean age: 231 days), lines were placed at bedside (technical success 100%) with 14 (13.3%) complications including infection (n=3), malposition (n=5), bleeding (n=0), thrombosis (n=2) and line occlusion (n=4). The infection rate was 0.78 per 1,000 line days. The total line days were 7,109, of which 3,258 were in the IR suite and 3,851 in the bedside group. There was no statistical significance for complication rate (P=0.55) or infection rate (P=0.57) between bedside and interventional suite placements. CONCLUSION: In a cohort of children receiving primary femoral tunneled central venous catheters, the complication and infection rates in a bedside setting are not significantly increased compared to the lines placed in an IR suite. The perception of increased infection and complications from bedside-placed tunneled central venous catheters appears to be hyperbolized.

Portosystemic shunt as a bridge to liver transplantation in infants: A comparison of two techniques.

Portosystemic shunts can serve as a bridge to liver transplantation in patients with end-stage liver disease by providing portal decompression to treat life-threatening variceal bleeding and prevent recurrent episodes until an organ becomes available. The conventional TIPS procedure, however, is technically challenging to perform in infants due to the small size of their intrahepatic vasculature. We report two cases of emergent creation of portosystemic shunts as a bridge to liver transplantation in infants with life-threatening variceal bleeding using a conventional TIPS technique in the first case and a percutaneous DIPS technique in the other. Both procedures were successful at reducing the portosystemic pressure gradient and preventing further variceal bleeds until a liver transplant could be performed. The novel percutaneous DIPS procedure is a valuable alternative to the conventional TIPS in infants, as it is better suited for small or challenging intrahepatic vascular anatomy.

Body MR angiography in children: how we do it.

Vascular pathology is ubiquitous in children. Common indications for angiographic imaging in the body include congenital anomalies, portal hypertension, assessing resectability of neoplasms, renovascular hypertension, vascular malformations, vasculitis, systemic vein thrombosis, and trauma. MR angiography, with or without the use of intravenous contrast agents, is therefore a mainstay in the repertoire of MR imaging in children. Pediatric contrast-enhanced MR angiography has benefited from several innovations in recent years, including improved hardware options like high-field-strength scanners and integrated high-density coil arrays, new sequences that combine parallel imaging, innovative k-space sampling and Dixon fat suppression with time-resolved imaging, new contrast agents with longer blood-pool residence time, and advanced post-processing solutions like image fusion. This article focuses on the principles of contrast-enhanced MR angiography of the body as it pertains to the physiologies and pathologies encountered in children. It also discusses tools to adapt the MR angiographic technique to the clinical indication, as well as pitfalls of post-processing and interpretation in commonly encountered vascular imaging scenarios in the pediatric body.

Respiratory diphtheria in the time of Omicron.

Abstract: Diphtheria is a potentially fatal bacterial infection caused by toxin-producing strains of corynebacteria, most often Corynebacterium diphtheriae and less commonly Corynebacterium ulcerans. Incidence of the disease has fallen significantly since the introduction of vaccination programs; it is now rare in countries with high vaccination coverage such as Australia. This article presents the most recent respiratory cases of diphtheria in two children in New South Wales-the first locally acquired childhood cases in Australia in 30 years-and discusses potential contributing factors. These encompass the lack of clinical awareness and the delays in laboratory diagnosis in regional laboratories. The cases also highlight the problem of vaccine hesitancy and the role that primary carers play in addressing these anxieties. While clinical management of the cases progressed well, factors in the public health responses were complicated by access to appropriate care and by delays in antibiotic sensitivity profiles. The public health response to these cases raises important considerations for clinicians and public health practitioners, including preparedness for rare and re-emerging diseases, the need for culturally safe environments and the importance of addressing vaccine hesitancy. Preparedness requires consideration of the capacity of regional health systems with fewer resources and of how public health departments can support response to multiple crises. Preparedness also relies on access to necessary diagnostic laboratory resources, on up-to-date guidelines, and on maintaining awareness among clinicians for these rare infections.

Induction of serum- and glucocorticoid-induced kinase-1 (SGK1) by cAMP regulates increases in alpha-ENaC.

Alpha-ENaC expression and activity is regulated by a variety of hormones including beta-adrenergic agonists via the second messenger cAMP. We evaluated the early intermediate pathways involved in the up-regulation of SGK1 by DbcAMP and whether SGK1 is a prerequisite for induction of alpha-ENaC expression. Submandibular gland epithelial (SMG-C6) cells treated with DbcAMP (1 mM) induced both SGK1 mRNA and protein expression. DbcAMP-stimulated SGK1 mRNA expression was decreased by actinomycin D and mRNA and protein expressions were attenuated by PKA inhibitors (H-89 and KT5720). Inhibition of PI3-K with either LY294002 or dominant negative PI3-K reduced DbcAMP-stimulated SGK1 protein and mRNA levels, attenuated the phosphorylation of CREB (a cAMP-activated transcription factor) and decreased alpha-ENaC protein levels and Na(+) transport. In addition, the combination of PKA inhibitors with dominant negative PI3-K synergistically inhibited DbcAMP-induced Na(+) transport. Inhibition of SGK1 expression by siRNA decreased but did not obliterate DbcAMP-induced alpha-ENaC expression. Thus, in a cell line which endogenously exhibits minimal alpha-ENaC expression, induction of SGK1 by DbcAMP occurs via the PI3-K and PKA pathways. Increased alpha-ENaC levels and function are partly dependent upon the early induction of SGK1 expression.

Temporal Evolution and Management of Fast Flow Vascular Anomalies in PTEN Hamartoma Tumor Syndrome.

Phosphatase and tensin homolog (PTEN) hamartoma tumor syndrome (PHTS) is characterized by formation of recurrent benign tumors described as PTEN hamartoma of soft tissue that may contain fast flow vascular anomalies (FFVA). The purpose of this study is to review the temporal evolution and management of FFVA in PHTS. A retrospective review of 22 patients (9 males), age 1 to 18 (median 9) years diagnosed with PHTS at a tertiary care pediatric hospital between October 2002 and August 2017 revealed 4 patients with FFVA. Imaging, management, and treatment complications were reviewed. During median follow-up of 8 (range: 4-13) years, ultrasound and magnetic resonance imaging performed for recurrent pain, showed progressive increase in the size of hamartomas and development of new FFVA in three-fourth patients. Medical management included pain medications, oral sirolimus, and physical and psychiatric therapy. Surgical excision of hamartoma ( n = 1) resulted in recurrence within 3 months. Between 4 and 24 (average 1.5/year) embolizations were performed per patient. Pain related to FFVA responded well to embolization. Pain secondary to PTEN hamartoma responded poorly to percutaneous sclerosant injection, but demonstrated improvement with sirolimus. There was no correlation between serum sirolimus levels and frequency/timing of recurrence of FFVA/hamartoma. Complications included sclerosant migration into digital arteries ( n = 1), subclavian vein stenosis due to glue migration ( n = 1), oral mucositis ( n = 4), and elevated triglycerides ( n = 4). Patients with PHTS present with recurrent pain requiring life-long management with a multi-disciplinary team. Pain due to FFVA responds to embolization, and pain due to hamartoma responds to sirolimus. This improves quality of life, but does not prevent disease progression.

Dynamic contrast enhanced magnetic resonance lymphangiography: Categorization of imaging findings and correlation with patient management.

OBJECTIVE: To review the technical aspects and categorize the imaging findings of dynamic contrast enhanced magnetic resonance lymphangiography (DCMRL) and correlate the findings with patient management options. MATERIALS AND METHODS: A retrospective review of patients who underwent DCMRL between June 2012 and August 2017 at a tertiary care paediatric hospital was performed. Twenty-five DCMRL studies were performed in 23 patients (9 males, 13 females, 1 ambiguous gender) with a median age of 4 years (range: 1 month-29 years). DCMRL imaging findings were reviewed, categorized and the impact on patient management was studied. RESULTS: DCMRL was technically successful in 23/25 (92%) studies. DCMRL findings were categorized based on the status of central conducting lymphatics (CCL) and alternate lymphatic pathways as follows: Type 1 - normal CCL with no alternate lymphatic pathways, Type 2 - partial (2a) or complete (2b) non-visualization of CCL with reflux of contrast into alternate pathways and Type 3 - normal CCL with additional filling of alternate pathways. Type 1 DCMRL patients (n = 5) were reassured and conservative management was continued, Type 2 patients (n = 10) had evidence of CCL obstruction hence thoracic duct ligation or embolization was avoided and other options such as lymphatic fluid diversion using Denver® shunt or lympho-venous anastomosis were used, and Type 3 patients (n = 8) were evaluated for elevated central venous pressure as a cause of lymphatic backflow in addition to Denver® shunt, lympho-venous anastomosis, thoracic duct ligation or embolization. CONCLUSION: DCMRL is an evolving imaging technique for understanding abnormalities of the central conducting lymphatics. Categorization of imaging findings may be helpful in guiding selection of management options.

Limited Post-observation Period in Pediatric Outpatient Ultrasound-Guided Liver Biopsies.

PURPOSE: We retrospectively studied whether a limited 2 h post-biopsy observation period after a percutaneous outpatient ultrasound-guided liver biopsy is a sufficient monitoring period for children. MATERIALS AND METHODS: This study is an IRB-approved retrospective cohort review of consecutive outpatient percutaneous ultrasound-guided liver biopsies from June 01, 2014, to June 30, 2016. A total of 198 biopsies in 192 patients (85 females and 113 males) underwent an outpatient ultrasound-guided liver biopsy between June 01, 2014, and June 30, 2016 (age range 3 weeks-18 years, mean 11.6 years). Outpatient biopsies were performed with a limited patient observation time [median (IQR) observation 2.25 (0.83) h]. RESULTS: Adequate histopathology was obtained in 99% (197/198) of cases. Only one case was determined by a pathologist as not sufficient to render a diagnosis. 84% (166/198) of the biopsies were performed with a 16G needle, and 16% (32/198) were performed with an 18G needle. Overall, seven complications were detected (3.5% of all biopsies, 7/198) in seven patients. All complications detected were minor, 1.5% (3/198) were categorized as SIR A and 2% (4/198) as SIR B. The most common complication included pain after biopsy (4/198), followed by rash at the biopsy site (3/198). No major complications were detected in our sample. CONCLUSION: In a consecutive cohort of children, the use of a limited 2 h observation period after an ultrasound-guided percutaneous biopsy was a sufficient monitoring period for complications. Additionally, we did not observe a high proportion of patients returning for follow-up medical care after discharge due to complications.

Single-Incision Versus Conventional Technique for Tunneled Central Line Placement in Children.

PURPOSE: A single-incision technique for tunneled central venous access has been described. This study evaluates whether single-incision technique in children is comparable to the conventional method, with regard to procedure time, fluoroscopy time, and complication rate. MATERIALS AND METHODS: This is a retrospective review of 303 internal jugular vein tunneled central catheter placements whose age ranged from newborn to 17 years (median 1.7 years) by pediatric interventional radiologists from January 2014 through December 2015. 223 catheters were placed (181 patients) using the single-incision technique, and 80 catheters were placed (72 patients) using the conventional two-incision technique. Data were obtained from electronic medical records and PACS including procedure time, fluoroscopy time, and complication rates which were compared for both single-incision and conventional techniques. RESULTS: Technical success for the single-incision and conventional technique groups was 99.1 and 98.8%, respectively. Early complication rate was 12.1% for the single-incision technique and 17.5% for the conventional technique (p = 0.254). Overall complication rate was 26% (3.8/1000 line days) for the single-incision technique and 37.5% (4/1000 line days) for the conventional technique (p = 0.085). Median procedure time was 25 min for the single-incision technique and 26 min for the conventional technique (p = 0.427). Median fluoroscopy time was 1.7 min in the single-incision group and 1.3 min in the conventional group (p = 0.085). CONCLUSION: The single-incision technique for central venous access has comparable procedure time and fluoroscopy time with no difference in complication rates between the two techniques in a pediatric population.

Optimal Diagnostic Yield Achieved With On-site Pathology Evaluation of Fine-Needle Aspiration-Assisted Core Biopsies for Pediatric Osseous Lesions: A Single-Center Experience.

CONTEXT: - Image-guided, fine-needle aspiration-assisted core needle biopsy with an on-site evaluation by a pathologist (FNACBP) of osseous lesions is not a common practice in pediatric institutions. OBJECTIVES: - To evaluate the diagnostic adequacy and accuracy of FNACBP for pediatric osseous lesions and to compare the adequacy with procedures that do not use fine-needle aspiration. DESIGN: - Six-year, retrospective review of 144 consecutive children biopsied for osseous lesions with and without fine-needle aspiration assistance. RESULTS: - Pathologic diagnosis was achieved in 79% (57 of 72) of the core biopsies without an on-site evaluation, 78% (32 of 41) of the open biopsies (9 with intraoperative consultation), and 97% (30 of 31) of the FNACBPs as the initial diagnostic procedure. Three FNACBP cases were preceded by nondiagnostic open biopsies. Among 34 lesions sampled by FNACBP, 33 (97%) succeeded with diagnostic tissue, with most (30 of 33; 91%) being neoplasms, including 16 malignant (48%), 13 benign (39%), and 1 indeterminate (3%) lesions. The most-common diagnoses were osteosarcoma (9 of 33; 27%) and Langerhans cell histiocytosis (7 of 33; 21%). In cases with follow-up information available, 93% (28 of 30) of the FNACBP-rendered diagnoses were clinically useful, allowing initiation of appropriate therapy. The FNACBP procedure had 100% specificity, sensitivity, and positive predictive value for all 14 malignant lesions, with the sensitivity being 88% in benign lesions. Most FNACBP procedures (32 of 34; 94%) yielded adequate material for ancillary testing. A gradual upward trend was observed for the choice of FNACBP as an initial diagnostic procedure for osseous lesions. CONCLUSIONS: - The FNACBP procedure yields sufficient material for diagnosis and ancillary studies in pediatric, osseous lesions and may be considered an initial-diagnostic procedure of choice.

Mechanical ventilation down-regulates surfactant protein A and keratinocyte growth factor expression in premature rabbits.

Surfactant-associated proteins (SP-A, SP-B, and SP-C) are critical for the endogenous function of surfactant. Keratinocyte growth factor (KGF) and vascular endothelial growth factor (VEGF) are key regulators of lung development. The objective of this study was to evaluate the effects of early mechanical ventilation on the expression of these important regulatory proteins in a preterm rabbit model. Premature fetuses were delivered at 29 d of gestation and randomized to necropsy at birth, i.e. no ventilation (NV), spontaneous breathing (SB), or mechanical ventilation (MV) for 16 h. MV animals were further randomized to treatment with dexamethasone (dex). Our findings showed that SB rabbits increased their expression of SP-A mRNA and protein after birth compared with NV controls. MV significantly attenuated this response in the absence of dex. Exposure to dex elevated SP-B mRNA expression in both SB and MV rabbits. KGF protein levels were markedly increased in SB animals compared with MV counterparts. VEGF levels were similar in SB and MV animals, but were significantly increased compared with NV controls. These data suggest that MV alters surfactant-associated protein and growth factor expression, which may contribute to injury in the developing lung.