01Approach to the Critical Patient/attcp39

Immediate priorities

›Airway and perfusion threats

›Hemodynamic instability

›Tachycardia with poor perfusion

›Hypotension is a late and ominous sign

›Septic shock from bowel necrosis or perforation

›Peritonitis or perforation signs

›Guarding and rigidity on abdominal exam

›Free air on plain radiograph is absolute contraindication to enema

›Altered mental status or lethargy

›Well-recognized atypical presentation especially in young infants

›Lethargy alone may be the sole presenting feature

›If hemodynamically unstable, IV fluid resuscitation and surgical consult before imaging

›Class I recommendation

›NPO status immediately

Monitoring and stabilization targets

›Initial stabilization bundle

›IV access with fluid resuscitation

›Normal saline 20 ml/kg bolus for signs of dehydration or shock

›Reassess after each bolus

›Continuous cardiac and oxygen saturation monitoring

›Tachycardia as ongoing perfusion marker

›NPO status on arrival

›Anticipate enema reduction or surgical intervention

›Analgesia

›Pain management prior to reduction is appropriate

›Only 7% of US children currently receive sedation during reduction

02History/hx75

Presenting symptoms

›Classic symptom triad

›Intermittent colicky abdominal pain

›Most common symptom, present in 84 to 95% of cases

›Episodes of severe pain with pain-free intervals

›Child may draw up legs or be inconsolable during episodes

›Vomiting

›Present in 66 to 71% of cases

›Typically nonbilious early in the course

›Bilious vomiting suggests obstruction and predicts enema failure

›Bloody or currant jelly stools

›Present in only 6 to 32% of cases

›More common with prolonged symptoms greater than 12 hours

›More common in infants under 1 year

›Late finding suggesting mucosal ischemia

Alarm features

›High-risk presentations

›Lethargy or altered mental status

›Atypical but well-recognized, especially in young infants

›May be the sole presenting feature

›Bilious vomiting

›Associated with bowel obstruction

›Higher enema failure rates

›Hemodynamic instability

›Tachycardia, hypotension, poor perfusion

›Suggests bowel compromise and shock

›Symptom duration greater than 24 to 48 hours

›Increased risk of enema failure

03Physical Exam/exam51

Vital signs and general appearance

›Hemodynamic and stability assessment

›Heart rate

›Tachycardia from pain, dehydration, or shock

›Persistent tachycardia despite analgesia suggests ongoing compromise

›Blood pressure

›Hypotension is a late and ominous sign

›Normal blood pressure does not exclude significant illness

›Temperature

›Fever may or may not be present

›Absence of fever actually increases suspicion for intussusception versus gastroenteritis

›General appearance

›Child may appear remarkably well between pain episodes

›Lethargy or decreased responsiveness is a red flag

Abdominal exam

›Key abdominal findings

›Palpable sausage-shaped mass

›Typically in the RUQ or epigastrium

›Palpable in up to 68% in some series

›Best felt during pain-free intervals

›RUQ tenderness

›Strong predictor with adjusted odds ratio 8.2

›Dance sign

›Emptiness in the RLQ where the cecum normally resides

›Abdominal distension

›Suggests bowel obstruction

›Peritoneal signs

›Guarding, rigidity, rebound tenderness

04Differential Diagnosis/ddx46

Surgical and life-threatening differentials

›Immediate threats to exclude

›Malrotation with midgut volvulus

›ICD-10 Q43.3

›Bilious vomiting in neonate or young infant is surgical emergency

›Upper GI series is diagnostic

›Incarcerated inguinal hernia

›Inguinal mass, irreducible

›Careful inguinal exam essential in irritable infant

›Meckel's diverticulum with bleeding

›ICD-10 Q43.0

›Painless rectal bleeding in young child

›Can also serve as a lead point for intussusception

›Necrotizing enterocolitis

›ICD-10 P77.9

›Primarily in neonates

›Abdominal distension, bloody stools, hemodynamic instability

Common mimics

›Frequently confused diagnoses

›Gastroenteritis

›ICD-10 A09

›Diarrhea and fever more prominent

›Pain is diffuse and not episodic

›Absence of fever and diarrhea favors intussusception

›Appendicitis

›ICD-10 K37

›More common in older children

›Persistent rather than intermittent RLQ pain

05Laboratory Tests/lt34

Core diagnostic labs

›Initial laboratory evaluation

›Complete blood count

›Leukocytosis may be present, not specific

›Leukopenia can indicate severe sepsis

›Not required for diagnosis

›Basic metabolic panel and electrolytes

›Assessment of dehydration from vomiting

›Electrolyte derangements correction prior to procedural sedation

›Stool guaiac test

›Occult blood supports diagnosis

›Present in significant proportion without visible blood

Severity and surgical preparation labs

›Pre-intervention labs

›Lactate

›Consider if concern for bowel ischemia or shock

›Elevated lactate greater than 2 mmol/l indicates tissue hypoperfusion

›Blood culture

›If sepsis or peritonitis suspected

›Obtain before antibiotics when feasible

›Type and screen

›If surgical intervention anticipated

›Bowel resection may be required

›C-reactive protein

›May be elevated but nonspecific

›Not required for diagnosis

›Point-of-care glucose

›Hypoglycemia risk in young infants during illness

06Diagnostic Tests/dt85

Scoring Systems

›Clinical prediction models

›Suh et al. clinical prediction model

›Absence of fever: 1 point

›Intermittent pain or irritability: 1 point

›Absence of diarrhea: 2 points

›RUQ tenderness: 2 points

›Score of 1 or greater achieves 100% sensitivity and negative predictive value

›Useful for identifying low-risk patients who may not need imaging

›Weihmiller et al. risk stratification decision tree

›Incorporates abdominal X-ray result

›Age greater than 5 months

›Absence of diarrhea

›Absence of bilious emesis

›Sensitivity 97%, negative predictive value 99%

›Ding et al. early recurrence prediction score

›Transverse colon location of intussusception

›Prior intussusception history

›Target sign diameter greater than 35 mm

›Peritoneal effusion on ultrasound

›Sonographic enteritis

›Score of 3 or greater predicts early recurrence with AUC 0.795

MRI

›MRI role in pediatric intussusception

›Limited role in acute setting

›Rarely used in acute intussusception management

›Availability and time constraints are limiting factors

›Potential problem-solving indications

›Characterization of complex lead points when CT is equivocal

›Evaluation for intestinal lymphoma without radiation exposure

›Practical limitations

›Requires sedation in young children

›Motion artifact risk during active illness

›Ultrasound and CT are preferred in acute management

CT

›CT abdomen indications

›Not first-line for diagnosis

›Ultrasound is preferred initial modality

›CT reserved for specific indications

›Lead point evaluation

›Consider in children older than 2 years with recurrent episodes

›More than 4 recurrences should prompt CT to evaluate for pathologic lead point

›Post-enema failure evaluation

›Assessment of bowel viability before surgery

›Free air excluded before further attempts

›CT findings in intussusception

›Target sign on axial images

›Crescent of mesenteric fat within intussusceptum

›Free air indicates perforation and surgical emergency

›Radiation considerations

›Minimize radiation in children

›Ultrasound preferred to avoid ionizing radiation

Ultrasound

›Abdominal ultrasound as first-line modality

›Diagnostic accuracy

›Sensitivity 94 to 98%, specificity 96 to 100%

›First-line recommended imaging modality

›ACR Appropriateness Criteria support ultrasound as first-line

›Classic ultrasound findings

›Target sign on transverse view

›Concentric rings from multiple bowel wall layers

›Pseudokidney sign on longitudinal view

›Crescent-in-doughnut sign from mesentery enclosing entering limb

›Additional sonographic information

›Evaluates for free peritoneal fluid

›Identifies pathologic lead points

›Assesses bowel wall vascularity as viability marker

›Transient small-bowel intussusceptions

›Incidental finding less than 2.5 cm without symptoms

›Usually self-limiting

›Does not require intervention

›Point-of-care ultrasound

›POCUS diagnostic performance

›Sensitivity 95%, specificity 98%

›Comparable to radiology-performed ultrasound

›Can expedite diagnosis at bedside

›ACEP Level B recommendation for emergency ultrasound

›POCUS technique

›High-frequency linear transducer for bowel assessment

›Scan RUQ and RLQ systematically

›Target sign confirmation in two planes

›Plain abdominal radiograph

›Limited diagnostic utility

›Sensitivity only 48 to 62% for intussusception

›Useful to exclude free air before enema reduction

›May show soft tissue mass, paucity of gas in RLQ, signs of obstruction

›Role as adjunct

›Weihmiller risk stratification tool incorporates X-ray findings

›Not sufficient to confirm or exclude intussusception alone

07Disposition/dispo34

Discharge criteria after successful reduction

›Criteria for safe discharge

›Tolerating oral fluids

›Clear liquid intake tolerated without vomiting

›Advancing to regular diet as tolerated

›Asymptomatic and pain-free

›No recurrence of episodic pain during observation period

›Reliable caregivers with clear return precautions

›Caregivers understand recurrence symptoms

›Observation period

›Early discharge 4 to 6 hours post-reduction is safe and cost-effective

›Reduces length of stay from approximately 23 hours to 9 hours without increased recurrence

›ED-discharged patients have slightly higher return within 48 hours (aOR 3.43)

›Re-reduction success rates remain equally high at 84 to 94%

Admission indications

›Criteria requiring inpatient admission

›Failed enema reduction

›Requires surgical consultation and likely operative management

›Hemodynamic instability or peritonitis

›Direct admission to pediatric surgical service

›Inability to tolerate oral fluids

›IV hydration and monitoring required

›Concern for pathologic lead point

›Further imaging and surgical evaluation needed

›Unreliable follow-up or social concerns

›Caregiver capacity to recognize recurrence

›Consider admission for infants younger than 1 year

›Higher recurrence risk

08Treatment/t68

Non-operative reduction

›Enema reduction as first-line treatment

›General principles

›First-line for all stable patients without peritonitis or perforation

›Surgical consultation should be obtained before reduction attempt

›Perforation risk during enema reduction is less than 1%

›Reduction success maintained up to 8 hours from diagnosis without increased complications

›Pneumatic air enema

›Success rate approximately 83% with fluoroscopy guidance

›Air pressure typically limited to 80 to 120 mmHg

›Fluoroscopic monitoring during insufflation

›Rapid pressure release if free air is detected

›Hydrostatic saline enema under ultrasound guidance

›Success rate approximately 88 to 90%

›Meta-analysis shows higher success, shorter reduction time, and fewer complications than air enema

›Lower perforation risk compared to pneumatic method

›Saline column height typically 1 metre above patient

›Repeated reduction attempts

›Second or third attempt may be considered if first attempt fails

›Delayed repeat attempts can be successful

›Surgical team should be present or immediately available

Procedural sedation and analgesia

›Pain management for reduction

›Analgesia before reduction

›IV opioids for pain control are appropriate

›Morphine 0.1 mg/kg IV or intranasal

›Fentanyl 1 to 2 mcg/kg IV as alternative

›Procedural sedation considerations

09Special Populations/sp45

Pregnancy

›Intussusception in pregnancy

›Rare occurrence but recognized

›Small bowel intussusception more common in adults including pregnant women

›Pathologic lead point more likely in adult onset

›Diagnostic considerations

›Ultrasound preferred as first-line to avoid fetal radiation exposure

›MRI as alternative to CT when advanced imaging needed

›Maternal physiologic changes affect symptom presentation

›Management modifications

›Multidisciplinary team including obstetrics

›Surgical intervention timing considers fetal viability and gestational age

›Anesthesia considerations for fetal monitoring during operative management

Geriatric

›Intussusception in older adults

›Different etiology than pediatric

›Pathologic lead point expected in nearly all adult cases

›Colonic malignancy is most common lead point in adults

›Small bowel intussusception may be transient or pathologic

›Diagnostic approach

›CT abdomen and pelvis with contrast preferred over ultrasound in adults

›Colonoscopy if colonic intussusception to exclude malignancy

›Management differences

›Enema reduction not standard in adult intussusception

›Surgical exploration typically required

›Bowel resection often performed to address lead point

Pediatrics

›Age-specific management considerations

10Background/b61

Epidemiology

›Incidence and distribution

›Incidence approximately 62 per 100,000 children per year

›Most common cause of intestinal obstruction in children aged 3 months to 5 years

›Peak incidence at 6 to 7 months of age

›Sex distribution

›Male predominance with male to female ratio approximately 2:1

›Males account for 60 to 68% of cases

›Geographic and seasonal variation

›Some seasonal clustering with respiratory viral illness peaks

›Association with rotavirus activity prior to vaccination era

›Recurrence epidemiology

›Recurrence rate 3.7 to 16.8% after nonoperative reduction

›Median time to recurrence approximately 4 days

›Only 1.5% recur within 48 hours of discharge

›Risk factors for recurrence include younger age, male sex, prior episodes, transverse colon location

Pathophysiology

›Mechanism of intussusception

›Telescoping mechanism

›One bowel segment invaginates into adjacent distal segment

›Most common: terminal ileum telescopes into colon (ileocolic)

›Creates three-layered mass of bowel

›Consequences of obstruction

›Venous and lymphatic obstruction occurs first

›Edema of the intussuscepted segment develops

›Arterial compromise leads to ischemia

›Mucosal sloughing produces currant jelly stool

›Untreated progression to necrosis and perforation

11Patient Discharge Instructions/pdi35

copy discharge instructions

›What happened to your child

›Intussusception is a condition where part of the intestine folds into itself

›It was successfully treated by a procedure called an enema reduction

›Air or fluid was gently used to push the intestine back into the correct position

›Home care instructions

›Diet after discharge

›Start with clear liquids and advance to regular diet as tolerated

›Small frequent feeds for infants

›Stop feeds and return to ER if vomiting returns

›Activity

›Normal activity as child tolerates

›No restrictions unless surgical intervention was performed

›Medications

›No specific medications required after successful reduction in most cases

›Give pain relief as needed for mild discomfort

›Return to ER immediately if your child has

›Return to ER warning signs

›Recurrence of episodic abdominal pain, crying, or drawing up of legs

›Vomiting especially if green or bile-colored

›Bloody or currant jelly stools

›Lethargy or decreased responsiveness

›Fever greater than 38.5 degrees Celsius

›Abdominal distension

›Refusal to eat or drink

›Child appears very unwell or you are concerned

›Follow-up plan

›Scheduled follow-up

12References/r16

Guidelines and key sources

›Primary evidence sources

›Long B, Easter J, Koyfman A. High Risk and Low Incidence Diseases: Pediatric Intussusception. American Journal of Emergency Medicine 2025. PMID 39987626

›Expert Panel on Pediatric Imaging, Nguyen HN, Chan SS, et al. ACR Appropriateness Criteria Abdominal Pain-Child. Journal of the American College of Radiology 2026

›Gluckman S, Karpelowsky J, Webster AC, McGee RG. Management for Intussusception in Children. Cochrane Database of Systematic Reviews 2017

›Lin-Martore M, Firnberg MT, et al. Diagnostic Accuracy of Point-of-Care Ultrasonography for Intussusception in Children. American Journal of Emergency Medicine 2022. PMID 35749802

›Liu L, Zhang L, Fang Y, et al. Air Enema Reduction Versus Hydrostatic Enema Reduction for Intussusceptions in Children. PloS One 2023. PMID 38498581

›Arshad SA, Hebballi NB, Hegde BN, et al. Early Discharge After Nonoperative Management of Intussusception Is Both Safe and Cost-Effective. Journal of Pediatric Surgery 2022. PMID 34756701

›Suh D, Lee JH, Oh S, Kwon H, Hwang JE. Development of a Clinical-Based Prediction Model for Pediatric Intussusception. Journal of Emergency Medicine 2025. PMID 40945392

›Ding Z, Qiang H, Li X, et al. Predicting Early Recurrence After Hydrostatic Reduction of Pediatric Intussusception. American Journal of Emergency Medicine 2026. PMID 42013625

›Strubel NA, Barton K, Baran TM, et al. Multicenter Analysis of Time Interval to Intussusception Reduction. Journal of Pediatric Surgery 2026. PMID 41708013

›Cohen DM, Helwig S, Poonai N, et al. Discharge Strategies Following Successful Ileocolic Intussusception Reduction. Journal of Pediatrics 2026. PMID 41443568

›Ultrasound guidelines

›ACEP Ultrasound Guidelines: Emergency, Point-of-Care, and Clinical Ultrasound Guidelines in Medicine 2023

›Li XZ, Wang H, Song J, et al. Ultrasonographic Diagnosis of Intussusception in Children: Systematic Review and Meta-Analysis. Journal of Ultrasound in Medicine 2021. PMID 32936473

›Weihmiller SN, Buonomo C, Bachur R. Risk Stratification of Children Being Evaluated for Intussusception. Pediatrics 2011. PMID 21242220

›Poonai N, Cohen DM, MacDowell D, et al. Sedation and Analgesia for Reduction of Pediatric Ileocolic Intussusception. JAMA Network Open 2023

Evidence & Review

Evidence & Review