Flashcards in Case 10 Deck (43)
What does an elevated leukocyte count with a left shift suggest?
What is on the differential diagnosis for UTI?
Otitis media, Roseola, Bacterial meningitis, Viral meningitis, Urinary tract infection, Pneumonia.
What are key findings from testing for a UTI?
Elevated leukocyte count, leukocytes/nitrate in urine.
What is the definition of a fever?
Greater than 100.4 deg F (38.0 deg C)
What is the definition of bacteremia?
Presence of viable bacteria circulating in blood.
What is occult bacteremia?
Bacteremia in a child with high fever.
What is sepsis?
Severe systemic illness caused by overwhelming infection of the blood stream by toxin producing bacteria. A diagnosis of sepsis typically requires a positive blood culture.
What is fever without a source?
Fever with no apparent focus of infection after careful history and physical examination.
What is fever of unknown origin?
Temperature of greater than 38.3 deg C (101 deg F) for at least 2 weeks duration with failure to reach a diagnosis after one week of evaluation.
What are meningeal signs?
Neck stiffness ("nuchal rigidity"), Kerning's sign, Brudzinski's sign.
What is nuchal rigidity?
Involuntary resistance to neck flexion. Clinician flexes patient's neck forward. In severe cases, increased extensor tone of neck and spine leads to hyperextension of entire spine or "opisthotonus".
What is Kerning's sign?
Flex patient's hips and extend knees, and see if patient resists knee extension from this position. Kerning's sign is positive when patient resits extension.
What is Brudzinski's sign?
Flex supine patient's neck to see if patient flexes hip and knee. Brudzinski's sign is positive if patient retracts legs toward the chest.
How do the majority of infants younger than 12 mo of age present with bacterial meningitis?
They will not have a positive Kerning's or Brudzinski's sign, but can present with a variety of findings including fever, hypothermia, lethargy, respiratory distress, poor feeding, vomiting, diarrhea, seizures, restlessness, irritability, and/or bulging fontanelles. However, if a febrile infant demonstrates a positive Kerning's or Brudzinski's sign, you must assume that he or she may have meningitis and perform a lumbar puncture.
What are the most likely differential diagnosis for a UTI?
Meningitis, Pneumonia, Occult bacteremia, Roseola
What are less likely differential diagnosis for a UTI?
Primary herpes simplex virus (HSV) gingivostomatitis, Otitis media, Vaccine symptoms, Viral upper respiratory tract infections (URI).
Consider in patients with unexplained fever with a non-focal history and physical examination. Consider degrees of toxicity, dehydration, and ability to retain oral intake. Fussiness and lack of appetite are common associated symptoms.
A worrisome diagnosis that must be considered in any febrile infant, regardless of presence or absence of meningeal signs. The only reliable way to rule out meningitis is with a lumbar puncture. Both viral and bacterial meningitis occur in children.
Most infants with pneumonia have cough and/or tachypnea, but fever may be the only presenting symptom. Even though chest exam is normal, pneumonia must still be considered.
Bacteremia (usually due to Streptococcus pneumoniae) is possible in a child with high fever and no source of infection on physical examination. Remember, the conjugated pneumococcal vaccine protects against only 13 pneumococcal serotypes.
Common viral illness due to human herpes virus 6 (HHV-6) that commonly presents with fever and few other symptoms. When the fever resolves, the child develops a diffuse erythematous maculopapular rash.
Primary herpres simplex virus (HSV) gingiovostomatitis:
Usually seen in children 10 mo-3 yr, but is estimated that only 10 to 30 percent of perioral HSV infections are symptomatic. Fever and irritability may be the initial symptoms, but oral lesions that start as vesicles and evolve to ulcerations would be seen shortly after symptoms onset.
What are vaccine symptoms?
Typically appear within one to two days after receiving vaccines. The MMR and varicella, however, produce fever 7 to 10 days after being administered in a small number of patients.
Viral upper respiratory tract infections (URI):
Presentation may include tachypnea, cough, nasal congestion and coryza. Associated fever is usually low-grade.
Bacterial pneumonia is possible in an ill-appearing infant with a fever for several days - even in the absence of respiratory symptoms or abnormal pulmonary findings. Some clinicians would consider getting a chest Xray in this setting.
Complete blood count:
-An elevated leukocyte count with a "left shift" (an elevation in the number of neutrophils, with an increased number of immature forms [ie bands, myelocytes, or metamyelocytes] suggests a possible bacterial infection.
-Most viral infections are associated with a normal or only slightly elevated leukocyte count and differential
-A positive nitrite test occurs when a gram-negative bacteria (eg E coli, Klebsiella, and Proteus species) - which can reduce urinary nitrate into nitrite - are present in the urine.
--A positive nitrite in a UA is highly specific for bacteruria (few false positives), but a negative nitrite has very poor sensitivity (lots of false negatives) for bacteruria of infection.
-Leukocyte esterase test detects esterase released from broken-down leukocytes. A positive test usually indicates presence of leukocytes in urine (pyuria), but pyuria may be seen in a variety of conditions besides UTI.
--Pyuria is defined as greater than or equal to 5 WBC per high power field in centrifuged urine or greater than or equal to 10 WBC per microliter in uncentrifuged urine.
Renal and bladder US:
Study provides information about renal structure and dilations in the collecting system. Useful for establishing presence of vesicoureteral reflux.
Voiding cystourethrogram (VCUG):
-This study defines the presence and degree of vesicoureteral reflux, an important risk factor for recurrences of UTIs.
-Should not be performed routinely in children after the first febrile UTI unless there are findings on the renal and bladder ultrasound that suggest high-grade vesicoureteral reflux (VUR). (Most VUR cases are mild and resolve spontaneously.)
-A VCUG is recommended after a second febrile UTI.