10 Flashcards
Vaccinations and fever
Timing of fever
Some Vaccinations that are known to cause them 3
The majority of adverse reactions to vaccines will occur in the first 24 to 48 hours after the first dose of the particular inoculation.
Examples:
The immunization against rotavirus is a live-virus vaccine that can cause fever in some infants, usually within the first several days.
Other live-virus vaccines, such as MMR and varicella, produce fever in a small number of patients 7–10 days after being administered,
Fever with no knowledge wn etiology 2
B has been selected by the expert.
Fever Without Source
The term fever without source is used when a complete history has been obtained and a detailed physical examination performed, and there is no identified source of the child’s fever.
Far and away the most common cause of fever without source in this age group is a viral syndrome. A small minority of children, however, may have a serious bacterial illness (SBI). Etiologies of SBI include the following:
Urinary tract infection (UTI)—the most common Meningitis Sepsis Pneumonia Bacterial gastroenteritis Osteomyelitis Septic arthritis
The other answers are not appropriate for this situation:
Fever of unknown origin (A) is defined as a temperature greater than 38.3 C (101 F) for at least two weeks’ duration with failure to reach a diagnosis after one week of evaluation.
Men in
Symptoms
Physical exam findings
Kernig’s sign is resistance to extension of the knee.
Brudzinski’s sign is flexion of the hip and knee in response to flexion of the neck by the examiner.
View illustrations of Kernig’s and Brudzinski’s signs.
Signs of Meningitis in Infants
The majority of infants younger than 12 months of age with bacterial meningitis will not demonstrate a Kernig’s or Brudzinski’s sign, but can present with a variety of findings including:
Fever Hypothermia Bulging fontanelles Lethargy Irritability Restlessness Paroxysmal crying (crying when picked up) Poor feeding Vomiting and/or Diarrhea However, if a febrile infant demonstrates a Kernig's or Brudzinski's sign, you must assume that he or she may have meningitis and perform a lumbar puncture.
Another physical finding suggestive of meningitis is neck stiffness or “nuchal rigidity.” This is an involuntary resistance to neck flexion when the clinician flexes a patient’s neck forward. In severe cases, increased extensor tone of neck and spine leads to hyperextension of the entire spine or “opisthotonos.”
Diff dx for fever
11
Urinary tract infection (UTI)
Commonly presents as fever and no focus on physical examination and a relatively unremarkable review of systems.
Fussiness and lack of appetite are common associated symptoms.
Risks for UTI include:
Uncircumcised male under 6 months (some say all males under 6 months and uncircumcised males under 12 months)
Any female under 24 months
Signs or symptoms pointing toward a UTI (e.g., suprapubic tenderness, history of UTI, foul-smelling urine)
Temp > 39 C (102.2 F), or fever ≥ 24 hours without a source.
Pneumonia
Most children with pneumonia have cough, tachypnea, fever, rales, or low SaO2.
It is unusual (but not impossible) for a child with pneumonia to have no symptoms referable to the respiratory system. Therefore, in an immunized child with no respiratory findings, a chest x-ray is not required. The exception is if the child’s WBC is > 20,000 cells X 103/μL. (Interestingly, however, if the child looks well, a WBC is not recommended.)
Sepsis/bacteremia
Sepsis is a systemic response to an infectious agent, whether bacterial, viral, or fungal. Inflammation occurs in tissues throughout the body, resulting in vasodilation, leukocyte accumulation, and increased capillary permeability.
Fever is usually—but not universally—present; young infants may present with hypothermia.
Children with sepsis generally do not look well.
Early in sepsis an elevated heart rate may be the only vital sign abnormality. Late signs include evidence of end-organ hypoperfusion: poor perfusion (delayed capillary refill), low blood pressure, altered mental status and other evidence of organ failure.
Bacteremia is simply the presence of bacteria in the bloodstream.
Occult bacteremia
In contrast to sepsis , the term “occult bacteremia” is applied when there is a positive blood culture in a well-appearing child.
The distinction is made because most children with occult bacteremia will NOT develop a serious bacterial illness (SBI), whereas a child with sepsis represents a medical emergency.
Bacterial meningitis
One of the most worrisome diagnoses to consider.
Both viral and bacterial meningitis occur in children, but typically the symptoms of bacterial meningitis are more severe.
Early in the illness, meningitis can present with fever and no other source of infection.
Most common causes in children are S. pneumoniae and N. meningitidis; remember, the conjugated pneumococcal vaccine protects against only 13 pneumococcal serotypes.
A fully immunized child 3-36 months of age who appears well, has a normal fontanel, and no nuchal rigidity or other signs of meningismus, is very unlikely to have meningitis. Therefore, no LP is needed in this group.
In very young children, the absence of meningismus cannot rule out this diagnosis.
Viral meningitis
Symptoms typically less severe than with bacterial meningitis.
Commonly caused by enterovirus.
In children, presents with fever.
May be other symptoms such as loose stools, rashes, or upper respiratory symptoms.
Roseola
Common viral illness in children under 2 years of age.
Caused by human herpes virus 6 (HHV-6).
A high fever is often the only symptom in the first few days of illness and typically lasts for 3 to 5 days.
Some patients develop a rash as the fever resolves; the rash can persist from 1 to 4 days.
Appropriate management for a child with roseola is to reassure the family that no other therapy is indicated.
More information: http://www.emedicine.com/ped/topic998.htm. (Accessed 5/31/2016.)
Primary herpes simplex virus (HSV) gingivostomatitis
Usually seen in young children between 10 months and three years.
Estimated that only 10 to 30% 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 are seen shortly after the onset of symptoms.
Otitis media
With an OM poor mobility and at least mild bulging of the tympanic membrane should be demonstrated. Without either of these signs, an OM cannot be diagnosed.
A red tympanic membrane by itself has no positive predictive value.
Vaccine reaction
Reactions to the vaccines given in infancy, such as fever, may appear within 1 to 2 days after receiving them.
Viral upper respiratory tract infection
Would expect congestion, cough, rhinorrhea, or coryza.
Testing for fever without source - 4
Urinalysis and urine culture
Since the most likely cause of SBI is UTI, a UA and catheterized urine culture should be obtained.
When antimicrobial therapy will be initiated, a catheterized (or suprapubic aspiration) specimen is required, rather than a bagged urine (AAP: Strong recommendation; E vidence Quality A)
If the child has low likelihood of UTI (see risk factors on previous card), clinical follow-up without testing is sufficient (AAP: Strong recommendation, Evidence Quality A).
CBC with differential
A CBC with differential may provide useful information in an ill-appearing infant with fever.
Abnormalities in the WBC count and the differential (such as a “left shift” toward more immature forms) can increase the likelihood that the child has serious bacterial illness.
A previously healthy child who looks well (they can have fever and fussiness but should not look toxic), however, does not require a CBC or blood culture.
Blood culture
A culture is warranted when the child has fever without source, is ill appearing, pale, and inconsolable. These are signs of a possible serious bacterial illness.
Lumbar puncture
When there are concerning signs of a possible serious bacterial illness—the child does not look well and is inconsolable and pale—and you have not identified a source for the fever, it is appropriate to obtain an LP.
Lumbar puncture- general rule
General Rule
If you are going to treat any febrile, ill-appearing, young infant (especially an infant less than 3 months of age) with parenteral antibiotics that will cross the blood-brain barrier (ceftriaxone is probably the most commonly used antibiotic in this setting), an LP to rule out meningitis should be performed:
Parenteral antibiotics will affect the CSF culture results, and
The antibiotic treatment of bacterial meningitis requires higher doses.
On the other hand, if the infant is not toxic, or has another obvious focus of infection, a lumbar puncture may not be necessary.
UA. Interpretation -3
Pyuria Defined
The traditional definition of pyuria uses microscopic analysis, with > 5 WBCs per high-power field (hpf) in a centrifuged urine considered positive. If a counting chamber is used, then > 10 WBCs per microliter in uncentrifuged urine is considered positive.
Nitrite Test
A positive nitrite test occurs when gram-negative bacteria, which can reduce urinary nitrate into nitrite, are present in the urine (esp. E. coli, Klebsiella, and Proteus spp) for an adequate amount of time (3-4 hours).
A positive nitrite on urinalysis is extremely helpful: It is highly specific for the presence of bacteria in the urine (few false positives).
A negative nitrite, however, has a very poor sensitivity (lots of false negatives) for bacteruria, especially in young infants who urinate frequently.
Leukocyte Esterase Test
A positive leukocyte esterase reaction detects esterases released from broken-down leukocytes.
A positive leukocyte esterase usually indicates the presence of white blood cells WBCs in the urine, but pyuria can be seen in a variety of conditions in addition to urinary tract infection. Thus, a positive leukocyte esterase test alone is insufficient to make the diagnosis of a urinary tract infection.
If both nitrites and leukocyte esterase are positive, it is strongly suggestive of a urinary tract infection.
Parenteral Antibiotic Treatment of Pyelonephritis - 4
In a child who has not recently been on antibiotics, the most likely cause of an initial episode of pyelonephritis is E. coli (85-90% of the time), with the remainder of cases caused by other enteric gram-negative organisms (Klebsiella or Proteus), or by enterococcus.
Antibiotic Comments
Ampicillin/gentamicin
Resistance rates of ampicillin to E. coli are rising, so ampicillin alone would not provide adequate coverage. (If sensitivity testing shows that the E. coli is sensitive to ampicillin, then ampicillin alone would be effective.)
When combined with gentamicin—which has excellent activity against coliforms—it is a good option for the treatment of pyelonephritis.
Ampicillin is also a good choice to treat enterococci.
Ceftriaxone
Provides excellent coverage against most gram-negative bacilli (the major exception being Pseudomonas aeruginosa)
Not effective against enterococci
Excellent safety profile in children
Can be given once daily
Calcium-containing medications cannot be given through the same IV line as they may interact with ceftriaxone to form precipitates in the lungs and kidneys
Piperacillin/tazobactam
Like ceftriaxone, provides excellent coverage against gram-negative bacilli
Adds coverage for Pseudomonas (less likely to be the etiology of an initial episode of pyelonephritis)
More expensive than other options
Not optimal therapy for enterococci
Ciprofloxacin
Can be used, but is not the best choice due to cost and potential adverse reactions in children - potential for damage to the articular cartilage, particularly the knee
Approved for children older than 1 year for complicated UTI with resistant organisms
Oral abc for pyelonephritis - 5
Susceptibilities are reported using parenteral antimicrobials. The clinician must choose an oral equivalent for outpatient treatment.
Cephalexin (Keflex) - 1st generation cephalosporins
Best choice: inexpensive and well tolerated
Sulfisoxazole
Wide resistance; should not be used
Nitrofurantoin
An acceptable concentration level is reached only in the urine, not in the blood; therefore, approved only for the treatment of cystitis, not pyelonephritis
Ciprofloxacin
Very expensive
Should not be used in children if alternatives are available, because of possible adverse reactions seen in tests with animals
Amoxicillin/clavulanate (Augmentin)
Would be effective, but—due to potential for skin and gastrointestinal adverse reactions—would not be the first choice.
Follow up studies for pyelonephritis
Ultrasound study of the kidneys and bladder
Provides information about renal structure and dilatations in the collecting system
Has replaced the intravenous pyelogram (IVP) for providing this information
Unless the illness is of unusual severity, or the child is not improving on antibiotics, the ultrasound may be obtained at completion of the antibiotic course.
Renal technetium scan
Provides evidence of pyelonephritis
Not required in a patient who has responded well to treatment
Voiding cystourethrogram (VCUG)
Demonstrates presence of vesicoureteral reflux, an important risk factor for recurrences of urinary tract infections
Should not be performed routinely in children after a first febrile UTI unless there are findings on the renal and bladder ultrasound that suggest high-grade vesicoureteral reflux, such as hydronephrosis. This is commonly the cause of a urinary tract infection in young infants.
Recommended after a second febrile UTI.
Vesicoureteral reflux
Grading
When to refer
Vesicoureteral Reflux (VUR)
Frequency
VUR is seen in 25-50% of infants evaluated following their first UTI.
Grading
According to the 1981 International Reflux Study Committee, there are 5 grades of reflux:
Grade Description
1 Urine refluxes part-way up the ureter.
2 Urine refluxes all the way up the ureter, but there is no dilatation of the calyces or collecting system.
3 Urine refluxes all the way up the ureter, with some dilatation of the ureter and/or blunting of the calyceal fornices.
4 Urine refluxes all the way up the ureter, with marked dilatation of the ureter and blunting and dilatation of the calyces.
5 Massive reflux into a grossly dilated, tortuous ureter, with calyceal dilatation and blunting, and loss of renal cortex.
Severity
Fortunately, most reflux is either Grade 1 or Grade 2, both of which have a very high rate of spontaneous resolution; most cases resolve within 2-5 years.
Grades 4 and 5 VUR occur much less commonly, but, unfortunately, spontaneous resolution is an infrequent occurrence; many of these patients eventually require surgical correction.
Some patients with Grade 3 VUR also may eventually require surgery if their reflux does not spontaneously resolve over time.
When to Refer
Patients with Grades 1-2 VUR may be followed by the primary care physician.
Patients with Grades 3-5 VUR should be referred to a urologist.
Surgical Repair of VUR
Current techniques include endoscopic injection of material in the area where the ureter enters the bladder and reimplantation of the ureter into the bladder.
