Symptom-Based Diagnosis in Pediatrics (CHOP Morning Report) 1st Ed.

CASE 8-4

Eight-Month-Old Boy

NATHAN TIMM

HISTORY OF PRESENT ILLNESS

A previously well 8-month-old male was brought to the emergency department because of increased sleepiness. The mother reports that her son was well earlier in the day, but during the last few hours she has noticed him to be extremely drowsy. Her son had two episodes of nonbloody nonbilious emesis during this period but no diarrhea. There was no history of fever, cough, or rash. The parents reported, however, that they had been cleaning the house with bleach, and although they did not witness any ingestion, his drowsiness seemed to coincide with the cleaning. There were no prescription medications in the house.

MEDICAL HISTORY

The child was full-term infant delivered via Cesarean section for fetal distress; however, the infant did well and was discharged to home after 48 hours. The pregnancy had been complicated by preecclampsia. The remainder of the past history was unremarkable.

PHYSICAL EXAMINATION

T 36.7°C; HR 133 bpm; RR 55/min; BP 118/57 mmHg; SpO2 99% in room air

Weight greater than 90 percentile; Height 75-90 percentile

In general, the child was well-developed and appeared lethargic. He had moist mucus membranes with no oral ulcers or burns. His pupils were equally round and reactive to light. His neck was supple. Cardiac and lung examination was unremarkable. The abdomen was nontender with active bowel sounds. There were no masses. Testes were descended bilaterally and there were no hernias. Rectal examination revealed normal tone with brown, hemoccult positive stool. The neurologic examination was significant for a lethargic appearing child who moved all four extremities, had symmetric facies, and responded to painful stimulation.

DIAGNOSTIC STUDIES

The complete blood count revealed a WBC count of 7100 cells/mm3 (70% segmented neutrophils, 1% eosinophils, 23% lymphocytes, 6% monocytes); hemoglobin, 12.0 g/dL; and platelet count, 274 000/mm3. Serum electrolytes, calcium, blood urea nitrogen, and creatinine were normal. The serum glucose was 111 mg/dL.

COURSE OF ILLNESS

An abdominal radiograph suggested a diagnosis (Figure 8-4).

Image

FIGURE 8-4. Abdominal radiograph.

DISCUSSION CASE 8-4

DIFFERENTIAL DIAGNOSIS

The etiology of a depressed mental status as described in this patient is diverse; however, clues from the history and physical can lead to the diagnosis. Ingestion should be high on the list in this particular age group. Parents were concerned about cleaning products. However, household bleach, soaps, and detergents cause mainly gastrointestinal irritation resulting in vomiting and mild diarrhea. Other possible ingestions resulting in a depressed mental status include alcohol, carbon monoxide, iron, clonidine, opiates, and sedative hypnotics. Closed head injury with expanding mass lesion should also be considered in a previously well child who presents with lethargy and vomiting. Although an infectious cause is unlikely given the absence of fever, early shigellosis is possible given the vomiting, abdominal pain, and hemoccult positive stool. However, shigellosis is an uncommon infection, and there is a much more common diagnosis that occurs in this age group that would explain the vomiting, hemoccult positive stool, and a depressed mental status.

DIAGNOSIS

The history of lethargy and emesis, the finding of hemoccult positive stool, and the presence of tachypnea were worrisome. The radiograph showed a paucity of bowel gas in the right abdomen as well as a soft tissue density protruding into a gas-filled loop of transverse colon. These findings were concerning for intussuseption. A barium enema identified an intussusception in the midtransverse colon that was easily reduced leading to flow of contrast into the nondilated bowel loops (see Figure 8-5). The diagnosis is ileocolic intussusception.

Image

FIGURE 8-5. Barium enema. The patient is prone so the right side of the image is the patient’s right side and the left side of the image is the patient’s left side. The images show a sequence from contrast injection into the rectum (A) with flow through the descending colon (B) , past the splenic flexure, across the transverse colon, past the hepatic flexure (C) and then you see the intussusceptum (D) and its reduction (E) followed by very brisk flow to the small bowel as the insussusception is reduced (F).

INCIDENCE AND EPIDEMIOLOGY

Intussusception is the most common cause of intestinal obstruction in children between the ages of 3 months and 2 years. Sixty percent occur in children who are less than 1 year old, and males are four times more likely to be affected than females. Ninety percent of the cases are idiopathic, and the most common type occurs when the distal ileum telescopes into the proximal colon. The other 10% have a lead point such as a Meckel diverticulum, polyp, or lymphoma.

CLINICAL PRESENTATION

The classic presentation of intussusception is a previously well child who develops intermittent episodes of colicky abdominal pain with “currant jelly” stools and an abdominal mass. Nevertheless, nearly 15% of children present without abdominal pain, only 40% have hematochezia, and 25% have a palpable mass. Therefore, nonspecific signs and symptoms such as vomiting, irritability, and decreased oral intake may be only indication that intussusception is present. Lethargy is a well described presenting complaint of intussusception. Although most cases described were also associated with other findings (hematochezia, abdominal mass), a high level of suspicion for intussusception must be maintained for any child presenting with altered mental status. Lethargy may be due to dehydration, shock, or cytokine release by the entrapped bowel wall.

DIAGNOSTIC APPROACH

History and physical examination findings will raise the clinical suspicion of intussusception.

Abdominal radiograph. Plain radiography is a helpful next step. Free air and obstruction can be identified on abdominal films; however, nearly 30% of patients with intussusception will have normal abdominal radiographs.

Abdominal ultrasound. Ultrasound, if available, provides a highly sensitive and specific test to diagnose or exclude intussusception. Additional benefits of ultrasound are patient safety and comfort, the ability to characterize lead points, and make alternative diagnoses. High-risk features such as absence of blood flow and fluid within the intussusception can be detected with the use of ultrasound.

Air or barium contrast enema. If ultrasound is not available then an air or barium contrast enema should be performed for the diagnosis and treatment of intussusception. Successful reduction rates are 90% or air and 65%-85% for barium or water soluble contrast enemas. Contraindications for the use of barium contrast enema include free air on plain films or clinical peritonitis.

TREATMENT

Barium enema has been the standard diagnostic and therapeutic tool for intussusception for the past 3 decades. Success rates at reduction approach 80%, yet drop off when symptoms have persisted for greater than 48 hours. Water-soluble contrast, air, and ultrasound guided saline enemas have also been described with equal effectiveness at reduction compared with barium, yet have the benefits of cleaner methods, less radiation exposure, and reduced risk of chemical peritonitis if perforation occurs. Surgical correction is necessary if enema reduction fails. Recurrence rate of intussusception is greater in children with definable lead points. Ten percent will recur after enema reduction, while surgical correction has a 2%-5% recurrence rate.

SUGGESTED READINGS

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2. Del-Pozo G, Albillos JL, Tejedor D, et al. Intussusception in children: current concepts in diagnosis and enema reduction. Radiographics. 1999;19:299-319.

3. Harrington L, Connolly B, Hu X, et al. Ultrasonographic and clinical predictors of intussusception. J Pediatr. 1998;132:836-839.

4. Kupperman N, O’Dea T, Pinckney L, Hoecker C. Predictors of intussusception in young children. Arch Pediatr Adol Med. 2000;15:250-255.

5. Losek JD, Intussusception: don’t miss the diagnosis! Pediatr Emer Care. 1993;9:46-51.

6. Lui KW. Air enema for diagnosis and reduction of intussusception in children: clinical experience and fluoros-copy time. J Pediatr Surg. 2001;36:479-481.

7. Luks FI, Yazbeck S, Perreault G, Desjardins JG. Changes in the presentation of intussusception. Am J Emer Med. 1992;10:574-576.

8. McGuigan MA. Bleach, soaps, detergents and other corrosives. In: Haddad LM, Shannon MW, Winchester JF, eds. Clinical Management of Poisoning and Drug Overdose. 3rd ed. Philadelphia: WB Saunders; 1998:830-835.

9. Myllyla V. Intussusception in infancy and childhood. Rontgenblatter. 1990;43:94-98.

10. Sargent MA. Plain abdominal radiography in suspected intussusception: a reassessment. Pediatr Radiol. 1994; 24:17-20.

11. Schnaufer L, Mahboubi S. Abdominal emergencies. In: Fleisher GR, Ludwig S, eds. Textbook of Pediatric Emergency Care. 4th ed. Philadelphia: Lippincott Williams & Wilkins; 2000;1519-1521.

12. Wyllie R. Intussusception. In: Behrman RE, Kliegman RM, Jenson HB, eds. Nelson Textbook of Pediatrics. 16th ed. Philadelphia: W.B. Saunders Company; 2000: 1072-1074.