Regarding the investigation of children with suspected pneumonia, which ONE of the following is INCORRECT?
Answer: D: A well-appearing child with cough and rales may be diagnosed clinically and treated as an outpatient. A child who appears ill or in whom the diagnosis is unclear requires further evaluation.
An arterial blood gas (ABG) should be considered in a child with severe respiratory distress. Serum electrolytes, blood urea nitrogen, and creatinine are useful in assessing the degree of dehydration and guiding fluid management when clinically relevant.The leukocyte count may be helpful in differentiating aetiology – peripheral WBC counts >15,000/mm3 , with predominance of mature and immature granulocytes, suggest bacterial infection, with pneumococcal pneumonia typically producing the highest WBC counts. Normal to elevated WBC counts with lymphocytosis may be seen in viral infections, and eosinophilia suggests chlamydial disease. Increased WBC counts with extreme lymphocytosis typically are associated with pertussis. BC is not very useful because they are positive in only 1 to 10% of cases of bacterial pneumonia.
Sputum cultures may be useful in adolescents but are not useful in younger children because contamination by organisms of the upper respiratory tract is common. Bacterial cultures of upper respiratory secretions are of no value as they reflect only colonization.
Patients with pleural effusions should have lateral decubitus radiographs to assess effusion size and loculation. Ultrasound is a useful ED modality to confirm fluid in the chest cavity. CT scan is useful to provide greater detail of effusions and lung abnormalities in critically ill children with complicated pneumonia. Thoracentesis for diagnostic and therapeutic purposes is important. Although most suggestive of bacterial infection, parapneumonic effusions also occur with mycoplasmal and occasionally with viral infections. Bronchoscopy with bronchoalveolar lavage may be useful in a severely ill child. Nasopharyngeal viral cultures, antigen detection for specific viral or bacterial agents, and serum antibodies for specific agents may be helpful in determining certain aetiologic agents. Skin testing for tuberculosis should be considered for patients with lobar pneumonia, pulmonary effusions or hilar adenopathy, especially in immunocompromised children or children who have recently immigrated from less developed countries.
Occasonally dehydration can result in a normal CXR, with rehydration revealing an obvious consolidation. Bacterial pathogens usually have alveolar infiltrates in a lobar distribution but may produce diffuse interstitial infiltrates. Viral and chlamydial infections tend to appear as diffuse interstitial infiltrates with associated hyperinflation and atelectasis. Chest radiographs also identify multilobar disease, pleural effusions, pneumatoceles and pneumothorax. Hilar adenopathy may indicate tuberculosis or malignancy. Children without comorbid conditions, who are without fever, unilateral wheezing or tachypnea, are unlikely to have pneumonia and a chest radiograph is unnecessary. Further, a Cochrane review demonstrated that for non-ill-appearing children with <14 days of symptoms and clinical signs of pneumonia, chest radiography does not reduce subsequent hospitalization rate, nor duration of symptoms. Routine chest radiography is not beneficial in ambulatory children over 2 months with acute lower respiratory infections.
References:
An 18-month-old boy presents with severe viral croup. He has an audible stridor on inspiration and expiration and severe respiratory distress. He weighs 11 kg.
Which ONE of the following is CORRECT?
Answer: C In severe croup, there is stridor at rest but the loudness of the stridor is a poor guide to severity. Severe upper airway obstruction is characterized by signs of severe respiratory distress, cyanosis and reduced air entry. However, the stridor is usually soft and may be expiratory as well as inspiratory.
Principles of management include the following:
Which ONE of the following is TRUE regarding normal developmental milestones in children?
Answer: A: A rudimentary understanding of developmental milestones is important, particularly when trying to assess if a child is toxic and unwell (assess if smiling), or if assessing traumatised children and establishing their risk of non-accidental injury when reviewing mechanism of injury and if injuries are developmentally appropriate (see Table below). Other important scenarios for reviewing milestones include the assessment of failure to thrive or neurological disease.
DEVELOPMENTAL MILESTONES:
Reference:
A 6-month-old boy has a heart rate of 180 bpm, a temperature of 38°C, a CRT of 1 second, a respiratory rate of 28 and normal SaO2 . His mother describes a brief coryzal illness of 1-day duration; the child is comfortable on his mother’s lap and is smiling.
Which ONE of the following is TRUE?
Answer: B: A knowledge of the normal variation with age of physiological parameters is important in assessing if a child is toxic or unwell (see Table below). Normal heart rate varies with age. Tachycardia can be a product of fever, anxiety, pain or fear but is also the first and most sensitive sign of cardiovascular compromise in the paediatric patient. When measuring the heart rate, the quality of the pulse can be extremely helpful. The quality of the brachial and radial pulses or the femoral and dorsalis pedis pulses palpated concurrently provides important information to differentiate cardiovascular compromise from benign causes of tachycardia. Bradycardia can be an ominous sign in an ill patient heralding cardiopulmonary failure and impending cardiac arrest. In this patient, a mild tachycardia is probably due to a raised temperature, especially since other parameters of sepsis – CRT, appearance, RR – are normal. Repeated examination and vital sign review is important to complete a full assessment, that is, normalization of HR when apyrexial would confirm the initial hypothesis. Blood pressure measurement should be obtained in ill patients of all ages. Infants and young children have excellent compensatory measures for maintaining blood pressure in the presence of significant loss of circulatory volume. Compensatory mechanisms include an increase in heart rate and systemic vascular resistance. When these compensatory mechanisms fail and blood pressure drops below normal, the patient moves from a state of compensated to decompensated shock. Obtaining an accurate blood pressure in infants and small children requires the appropriate selection of the blood pressure cuff. A properly-sized cuff should cover approximately two-thirds of the circumference of the upper arm and extend at least 50% of the length of the upper arm.The lower limit for acceptable BP in children older than 1 year can be quickly estimated by using the following formula: systolic BP (mmHg) = 70 + (2 x age in years). The pulse oximetry waveform can also be used to determine systolic BP. Observing for the return of a plethysmographic waveform of the pulse oximeter as the BP cuff is deflated has been shown to correlate closely with conventional methods of BP measurement.
Lower limits of systolic BP as suggested by the American Heart Association in the ECC guidelines 2000:
NORMAL PAEDIATRIC VITAL SIGNS FOR AGE:
Adapted from Dieckmann R, Brownstein D, Gausche-Hill M, editors. Pediatric education for pre-hospital professionals. Sudbury: Mass, Jones & Bartlett, American Academy of Pediatrics, 2000:43–45.
Regarding physiological parameters in children and how they may differ from adults, which ONE of the following is CORRECT?
Answer: C: It is not unusual for infants to have periodic breathing with episodes of apnoea lasting up to 20 seconds. Their central control of ventilation matures with age and ‘periodic breathing’ is much less common by 6 months of age. These episodes may be benign but these babies usually require a careful history, examination and focused investigation to exclude signs of CNS disease (intracranial haemorrhage, seizures, meningitis, signs of NAI – clinical exam), early sepsis (clinical exam, temperature observation with septic screen if febrile, urine MCS), metabolic or electrolyte abnormality (BSL, U/E, venous gas and ammonia if appears encephalopathic) or dehydration due to poor feeding or GI losses. Obvious respiratory causes can be ruled out by careful respiratory exam, and cardiac/congenital heart disease likewise. Drug ingestion or medications taken by a breastfeeding mother should also be considered. A period of observation is usually required to ascertain if the baby is well, to support the diagnosis of benign physiological apnoea of the newborn. To be considered abnormal, periodic breathing must be associated with a drop in heart rate or oxygen saturation, or symptoms of peri-oral cyanosis or unresponsiveness.
The large surface area-to-weight ratio in young infants can result in heat loss and temperature instability. However, the need to maintain thermoregulation and normothermia needs to be balanced with the potential benefits in maintaining a hypothermic state in the 34–35°C range, in a child with an out-of-hospital arrest. More data is needed to establish whether hypothermia will deliver the same improvements in mortality and morbidity for children as the evidence suggests for adult out-of-hospital cardiac arrest.
Newborns are obligate nose breathers. Older infants are often preferential nose breathers, and nasal obstruction from secretions can result in significant airway compromise. An irritable and crying infant may just be learning to mouth-breathe when the nose is obstructed.
Because of the elasticity of the cervical spine in young children, spinal cord injuries without radiographic abnormalities (SCIWORA) can occur. These injuries result in ligamentous instability, which if ignored may result in significant morbidity or mortality.
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