Pediatric Blunt Abdominal Trauma Does this patient need an Abdominal CT?

OBJECTIVES  Review Anatomic and Physiologic Differences of Pediatric Patients  Review Mechanisms of Pediatric Abdominal Trauma  Discuss Prediction Rules for Severe/High Risk Abdominal Trauma  Discuss Clinical Decision Tools Used to Determine Need for Abdominal CT  Develop a Complete Clinical Approach to Pediatric Blunt Abdominal Trauma

Why Review Pediatric Blunt Abdominal Trauma  Trauma is the #1 cause of death and disability in children >1 year old  Head and Thoracic are the most common  But…Abdominal Injuries are Most Unrecognized Cause of Death  90% of Abdominal Injuries from Trauma are Blunt Abdominal Injuries  Understanding of management pediatric abdominal injury important to future

What Makes Pediatric Patients Different?  Abdominal organs are relatively larger  Abdominal muscles are poorly developed  Less abdominal fat  Ribcage compliant leads to transmission of force to liver and spleen  Greater force per BSA leads to multiple injuries  Large BSA leads to Hypothermia  Difficult to identify if patient in pain  Kids cry due to pain  Kids cry because doctors are scary  Kids cry because parents are not holding them

Common Chief Complaints  MVC  Seat-Belt Syndrome  Pedestrian Struck by Motor Vehicle  Falls  Bicycle Injury – Handlebars (often Delayed Presentation)  Sports Injury  Non-accidental Trauma

 MVC  Most common cause blunt abdominal injury  Inappropriately restrained child 3x more likely to suffer abdominal injury  Spleen and Liver injury most common  Seat-Belt Syndrome  Etiology typically inappropriate seat-belt use  Hip and Abdominal Contusions, Pelvic Fx, Lumbar Spine Injury  Definition: area of erythema, ecchymosis and/or abrasion across abdominal wall resulting from seat belt restraints  Sokolove et al: RR 2.9 if seatbelt sign present

 Bicycle Injury  Handlebar injury – direct impact during fall  Delayed presentation – Average 34.5 hours post fall  Klimek et al Retrospective review 40 patients <16 yo  8 required operative intervention  Nonaccidental Trauma  If story does not sound right, high suspicion for NAT  Roaten et al review of 6186 trauma patients <18 yo  7.3% injury secondary to NAT  Fall with injuries >>>> mechanism  Multiple Injuries  Abnormal bruising patterns

So…Who Needs a CT Scan? Why Do We Care?  CT scans pose increase risk to pediatric patients  Ionizing radiation increases risk of malignancy  Growing tissues and organs children more sensitive to radiation than adults  Estimated risk of fatal cancer from radiation  1/1000 pediatric CT scan  0.18% lifetime risk for Abdominal CT in 1 year old  ALARA principle

Prospective Observational Study; One Level 1 Trauma Center 1,119/1,324 patients enrolled with at least 1 variable – used as study sample Utilizes 6 ‘High-Risk’ variables, if any present – concern for significant intra-abdominal injury 1.Low age-adjusted Systolic Blood Pressure 2.Abdominal Tenderness 3.Femur Fracture 4.Increased LFTs (AST >200 U/L, ALT >125 U/L) 5.Microscopic Hematuria (>5 rbc/hpf) 6.Initial Hematocrit <30%

 Inclusion Criteria:  <18 y/o  Underwent Definitive Test: Abd CT, DPL, Laparotomy/Laparoscopy  Exclusion Criteria:  Penetrating Trauma  Pregnant  Trauma >24 hours prior to presentation  Primary Outcomes: Intra-abdominal injury – spleen, liver, GB, pancreas, adrenal, kidney, ureter, bladder, GI tract, vascular structure Intra-abdominal injury requiring acute specific Intervention 1. Blood Transfusion for anemia 2/2 intra-abdominal hemorrhage 2. Angiographic embolization 3. Therapeutic intervention at laparotomy

 Results:  157/1,119 (14%) had intra-abdominal injuries  754/1,119 tested positive for prediction rule  365/1,119 tested negative; 8 false negatives  Sensitivity: 94.9%  Specificity: 37.1%  Potential Strength:  Utilization of prediction rule would decrease 1/3 Abd CT  Rapid identification of low risk for abdominal pain  Weaknesses:  One institution  No FAST exam  8 missed cases  Not included: (1) Transfers from other hospitals  (2) Patients observed without CT/DPL/Surgery

 3 patients – tenderness or trauma over costal margins  2 patients – decreased mental status (GCS 9, 12)  1 patient – underwent laparotomy but had seatbelt sign on exam, no significant intervention in OR  1 patient – other injuries  1 patient – developed tenderness during observation time in ED  7/8 only observed in hospital

 Prospective, Observational Cohort blunt torso trauma at PECARN centers  Enrollment: May 2007 – January 2010  Exclusion Criteria:  Injury >24 hours prior to presentation  Pregnancy  Transfer from outside hospital  Penetrating trauma  Preexisting neurologic condition impeding reliable exam

Inclusion Criteria

Primary Outcomes  Intra-abdominal Injury - 761/12,044 patients (6.3%)  Radiographically or surgically apparent injury to: spleen, liver, urinary tract, GI tract, GB, pancreas, adrenal, vasculature  Underwent Acute intervention (1.7%)  Death caused by injury  Therapeutic intervention at laparotomy  Angiographic embolization  Blood transfusion for anemia 2/2 hemorrhage  IV fluids for 2+ nights with pancreatic or GI injuries

Derived Prediction Rule Variables 1. Abdominal Wall Trauma or Seat Belt Sign 2. GCS <14 3. Abdominal Tenderness 4. Evidence Thoracic Wall Trauma 5. Complaints of Abdominal Pain 6. Decreased Breath Sounds 7. Vomiting

 Limitations  No FAST exam/Ultrasound utilized  Abd CT/DPL/Laparoscopy not mandated so clinically silent Intra-Abdominal Injuries may have been missed  Performed at Highly Specialized Pediatric Trauma Centers

Volume 22, Issue 9, pages 1034–1041, September 2015 Can I Trust My Gut?

Prediction Rule Sn >>>> Clinical Suspicion Sn Prediction Rule Sp <<<< Clinical Suspicion Sp However – despite low clinical suspicion, CT abd ordered on many patients

 Retrospective Analysis of Prospectively Collected Data  One Level 1 Trauma Center, Jan 2010 – Dec 2012  Radiology Resident performed all FAST studies  Primary Outcomes  Free Fluid in Abdomen  Intra-Abdominal Injury  Negative Intra-Abdominal Injury determined by Neg CT or Follow-up Appt

CONCLUSIONS  History and Exam Vital for Evaluation of Pediatric Blunt Abdominal Trauma  GCS score, Seat Belt Sign, Abdominal Wall Tenderness, Distracting Injuries  Vital Signs – Remember Age Adjusted cut-offs  Laboratory Tests ARE useful and can be predictive of Injury  UA – gross hematuria  AST/ALT  CBC  Utilized adjunct Testing  FAST exam  Ultimately, predictive scores are useful tools but cannot substitute for clinical judgement

Questions???  References Available Upon Request