Nccu clinical guidelines. section 2:respiratory problems and management

WOMEN AND NEWBORN HEALTH SERVICE
NCCU CLINICAL GUIDELINES
SECTION: 2
RESPIRATORY PROBLEMS AND MANAGEMENT
Section 2: Respiratory problems and management Neonatology Clinical Care Unit Guidelines King Edward Memorial/Princess Margaret Hospitals PNEUMONIA
Infection in the lung, most commonly bacterial but may be viral. May be categorised into the following: Pneumonia acquired from the mother: congenital, transnatal EPIDEMIOLOGY
The incidence of pneumonia acquired from the mother is 0.5% of all live births.
For nosocomial pneumonia, intubation is the single most important predisposing factor, increasing
the risk by 4 times compared to non-intubated patients.
PATHOPHYSIOLOGY
Newborn infants have an immature immune response and hence neonates are predisposed to infection. Diminished amounts of secretory IgA may result in upper airway colonisation. Decreased opsonisation impairs levels of fibronectin and complement function, in addition to the decreased macrophage function and impairment of the alternative and classical pathways. Focal atelectasis or an absent cough prevents effective mucociliary clearance. Intubation results in a significant iatrogenic breach of multiple anatomical defences. The most common infecting organisms are bacteria including Group B Streptococcus & E. coli. Enterococcus, Klebsiella, Haemophilus influenzae, and Staphylococcus are also frequently cultured. Most bacterial infections are the result of aspiration of flora, and may be acquired before, during, or after birth. The lung develops an inflammatory reaction, impaired immune function, cytokine release, free radical release (with impaired anti-oxidant pathways) causing cell damage. Viral infection is either transvaginal or is transmitted to the fetus earlier in the pregnancy via hematogenous placental transfer. Viruses cause disruption to ciliary function, mucus quality, and integrity of the epithelial mucosa. The most common virus to cause pneumonia is Herpes simplex, but Adenovirus and Enterovirus are also associated with a high degree of mortality. Listeria monocytogenes is the most common intracellular pathogen associated with acquired pneumonia. The degree of pathogenicity is probably due to depressed cytolytic function of neonatal natural killer cells, and impaired phagocytic function. Candida species account for the majority of fungal infections in infants in the first couple of months of life. It is acquired during gestation or at delivery, or may result as an overgrowth secondary to broad-spectrum antibiotic use, from aspiration of contaminated material or hematogenous spread in disseminated infection. Natural killer cells, T-cells, and This document should be read in conjunction with the NCCU Disclaimer. neutrophils are involved in the immune response to eradicate fungus, all of which may be depressed in the normal or sick neonate. CLINICAL PRESENTATION
The diagnosis is made on history and clinical symptoms. Factors that may suggest pneumonia
include:
A history of symptoms of amnionitis, and chorioamnionitis. The risk of these are increased in preterm labour, prolong active labour with cervical dilation, rupture of membranes before the onset of labour, prolonged rupture of membranes, and frequent obstetric digital exams. A history of maternal fever, the need for maternal antibiotics in labour, or a history of Group B Streptococcus on a high vaginal swab etc. SYMPTOMS INCLUDE
The infant may be febrile and show other signs of sepsis such as poor perfusion and hypotension. Consider fungal infection in an infant who has been on broad spectrum antibiotics, who presents with a clinical deterioration, hyperglycaemia and thromboctopenia. In transnatal pneumonia there is no evidence of amnionitis or maternal infection. The infant is thought to aspirate vaginal bacteria during the birth process. The onset of clinical signs is delayed for a few hours or days. Pneumonia may be one symptom of a clinical spectrum of sepsis. The clinical presentation of sepsis is very non-specific. Infants may present with any or all of the following: Abdominal symptoms: distended abdomen, bile stained aspirates. Metabolic derangement: hypoglycaemia, renal impairment, acidosis, electrolyte instability, transaminitis with concomitant coagulopathy. The complications of sepsis are numerous, depending on the severity and number of organs involved. Pneumonia may result in acute complications of pulmonary haemorrhage, pneumothorax, surfactant inactivation, and acute hypoxic respiratory failure. INVESTIGATIONS
CXR (AP and Lateral) X-ray findings may not be specific in pneumonia but may show non-specific areas of consolidation or atelectasis. FBC and U&Es, glucose, septic screen TREATMENT
1. Routine treatment is amoxil/gentamicin for the first infection, and then with more broad
spectrum antibiotics (add cefotaxime/cephalothin or vancomycin/metronidazole if suspecting gram negative or staphlococcal infection). 2. Consideration should be given to the use of: 3. Amoxycillin in place of Penicillin in case of Listeria. Section: 2 Respiratory problems and management King Edward Memorial/Princess Margaret Hospitals This document should be read in conjunction with the NCCU Disclaimer 4. The use of Metronidazole if anaerobic infection is likely (to be discussed with the consultant). 5. Amphotericin when fungal infection is possible The prognosis is good if the infection is treated early and there is minimal end organ involvement/damage. Gram negative and fungal infection can be overwhelming and invariably is not just isolated to the lungs. Congenital viral infections (rubella, toxo etc) generally have a poor prognosis if infected in the first trimester, whereas other viral pneumonias at birth are dependent on the aetiology: ie. Herpes, Adeno, and Enteroviruses have a poor acute prognosis, while CMV infection may present with an acute illness and lead to developmental delay and/or a hearing deficit from CNS spread. ASPIRATION PNEUMONIA
Inhalation of milk or other agents, associated with respiratory symptoms. The epidemiology is dependent on the cause of the aspiration. 1. Sucking / Swallowing in-coordination caused by: Secondary to structural malformations or neurological disorders, cleft palate, Pierre-Robin syndrome, tracheo-oesophageal fistula, laryngeal cleft, hypoxic-ischaemic encephalopathy. Syndromes with poor sucking eg. Prader-Willi. 2. Syndromes attributed to Gastro Oesophageal Reflux (GOR). 3. Massive regurgitation and inhalation of a feed. PATHOPHYSIOLOGY
The anatomy of the pharynx and larynx is largely responsible for protecting the airway from
inhalation. This is aided by ‘defensive reflexes’. Material in the pharynx initiates swallowing and
reflex breath holding. If the airway is still threatened, additional reflexes are provoked with the aim
of protecting the airway. These include more prolonged apnoea, choking, laryngospasm and
coughing. These mechanisms are less effective in the neonatal period than in older children and
adults.
CLINICAL PRESENTATION
The preterm infant has greater problems including:
Immature sucking/swallowing coordination, which may be overwhelmed by oral feeding. A higher incidence of GOR with increased risk of regurgitation. Compromised central sucking control, especially if there is neurological damage. Defence mechanisms such as apnoea may result in more severe symptoms. Coordination of sucking, swallowing and breathing is more difficult at all gestations if the infant is sedated (opiates) or if the infant is tachypnoeic. Aspiration is seen in these instances: Section: 2 Respiratory problems and management King Edward Memorial/Princess Margaret Hospitals This document should be read in conjunction with the NCCU Disclaimer In a term infant who during a breast/bottle feed in the first 48-72 hours of life chokes, splutters and may be transiently apnoeic and blue. Many of these are at the extreme end of normal spectrum in response to feeding. At any time after birth and there will usually be a history clearly available. Silent aspiration in an ill or convalescent infant in the NICU provoking the apnoea alarm. Pneumonia following aspiration is more likely in infants with neurological defects, structural INVESTIGATIONS
Chest X-ray may show changes especially in the RUL or RLL. Alternative diagnoses especially infection should be considered. If the infant is very unwell-investigate as per general respiratory management. A barium swallow may be indicated to examine feeding coordination and to whether aspiration is present. MANAGEMENT
As pneumonia is possible, we would advise to treat with antibiotics if the infant is clinically very
unwell, or the infant has an immune-deficiency. Otherwise treatment is dependent on the extent of
pulmonary compromise and the reason for aspiration.
Section: 2 Respiratory problems and management King Edward Memorial/Princess Margaret Hospitals This document should be read in conjunction with the NCCU Disclaimer

Source: http://kemh.health.wa.gov.au/services/nccu/guidelines/documents/2/Pneumonia_aspirationpneumonia.pdf