Light and Acoustic Environment In NICU

Lighting
Planning appropriate lighting for the NICU requires consideration of the disparate needs of both the babies and staff. In general, babies need very little light, but exposure to moderate levels of   illumination during part of the day may help establish circadian rhythmicity.

The lighting will be different in many areas in the NICU as illumination of a procedure area will vary from other ambient lighting situations. Flexibility in lighting levels is required as infants' needs change at different stages of development. Control of illumination should be accessible to both staff and families, and the design should include multiple light switches. If linear fluorescent lamps are used, the color designation should be “RE80.” All fixtures should have filters or shields that block ultraviolet radiation and minimize the risk to babies and staff if a bulb should shatter.

Staff need moderate levels of illumination at the bedside to evaluate babies and to perform charting and manual tasks.

At times, intense levels of illumination are necessary to perform procedures and for phototherapy of hyperbilirubinemia. 

It is doubtful that babies need natural lighting, but studies of adult office workers and hospital patients document the benefit of windows for staff and families. A multilevel lighting scheme should be considered by the design team:

1. Ambient lighting in infant care areas.

Lighting levels are adjustable through a range of 10 to 600 lx (1 to 60 foot-candles) as measured on a

horizontal plane. A control thermistor should allow for immediate darkening if necessary. Electric light sources should have a color rendering index (CRI) of no less than 80 and a gamut area index (GA) of no less than 80 and no greater than 100. The optical reflectors in the light fixture shall have a neutral finish  and unnecessary ultraviolet or infrared radiation shall be avoided. Any ambient lighting utilized should avoid the infant's direct line of sight.

2. Procedure lighting in infant care areas.
Separate procedure lighting should be present at each infant bed and be capable of providing no less
than 2,000 lx. In addition, the light output must be framed to exclude extension beyond its illumination field. Temporary increases in illumination may be necessary for clinical evaluation or performing a procedure. It is important not to increase lighting levels for adjacent babies. Intense light may be harmful to the developing retina. It is best to permanently mount a procedure light than to have a free-standing floor light, so that space can be maximized and accidents avoided.

Oral Candidiasis In Children

Oral thrush, or oral pseudomembranous candidiasis, is a superficial mucous membrane infection that affects approximately 2–5% of normal newborns. Infants acquire Candida from their mothers at delivery and remain colonized.

Thrush may develop as early as 7–10 days of age. The use of antibiotics, especially in the 1st year of life, may lead to recurrent or persistent thrush. The plaques of thrush invade the mucosa superficially and may be found on the lips, buccal mucosa, tongue, and palate. Removal of plaques from these surfaces may cause mild punctate areas of bleeding, which helps to confirm the diagnosis.

Thrush may be asymptomatic or may cause pain, fussiness, and decreased feeding. It is uncommon after 12 months of age but may occur in older children treated with antibiotics. Persistent or recurrent thrush with no obvious predisposing reason, such as recent antibiotic treatment, warrants investigation of an underlying condition such as diabetes mellitus or immunodeficiency, especially vertically transmitted HIV infection.

Treatment:
Treatment of mild cases may not be necessary.

Pathophysiology of Cystic Fibrosis

Cystic fibrosis (CF) is an inherited multisystem disorder of children and adults, characterized chiefly by obstruction and infection of airways and by maldigestion and its consequences.

CF is inherited as an autosomal recessive trait. The CF gene codes for a protein of 1,480 amino acids called the CF transmembrane regulator (CFTR).

Four long-standing observations are of fundamental pathophysiologic importance:

1. failure to clear mucous secretions,
2. a paucity of water in mucous secretions,
3. an elevated salt content of sweat and other serous secretions, and
4. chronic infection limited to the respiratory tract

In addition, there is a greater negative potential difference across the respiratory epithelia of CF patients than across the respiratory epithelia of control subjects. Aberrant electrical properties were also demonstrated for CF sweat gland duct epithelium. The membranes of CF epithelial cells are unable to secrete chloride ions in response to cyclic adenosine monophosphate (cAMP)–mediated signals and, at least in the respiratory tract, excessive amounts of sodium are absorbed through these membranes.

Cyclic AMP-stimulated chloride conductance is a function of CFTR itself; this function is absent in epithelial cells with many different mutations of the CFTR gene.

The postulated epithelial pathophysiology in airways involves an inability to secrete salt and secondarily to secrete water in the presence of excessive reabsorption of salt and water. The proposed outcome is insufficient water on the airway surface to hydrate secretions. Desiccated secretions become more viscous and elastic (rubbery) and are harder to clear by mucociliary and other mechanisms.These secretions are retained and obstruct airways, starting with those of the smallest caliber, the bronchioles. Airflow obstruction at the level of small airways is the earliest observable physiologic abnormality of the respiratory system.

Atrial Septal Defect

Introduction:
Atrial septal defects (ASDs) can occur in any portion of the atrial septum (secundum, primum, or sinus venosus), depending on which embryonic septal structure has failed to develop normally. Less commonly, the atrial septum may be nearly absent, with the creation of a functional single atrium. Isolated secundum ASDs account for ?7% of congenital heart defects.

The majority of cases of ASD are sporadic; autosomal dominant inheritance does occur as part of the Holt-Oram syndrome (hypoplastic or absent radii, 1st-degree heart block, ASD) or in families with secundum ASD and heart block.

Pathophysiology:
An isolated valve-incompetent patent foramen ovale (PFO) is a common echocardiographic finding during infancy. It is usually of no hemodynamic significance and is not considered an ASD; a PFO may play an important role if other structural heart defects are present. If another cardiac anomaly is causing increased right atrial pressure (pulmonary stenosis or atresia, tricuspid valve abnormalities, right ventricular dysfunction), venous blood may shunt across the PFO into the left atrium with resultant cyanosis. Because of the anatomic structure of the PFO, left-to-right shunting is unusual outside the immediate newborn period. In the presence of a large volume load or a hypertensive left atrium (secondary to mitral stenosis), the foramen ovale may be sufficiently dilated to result in a significant atrial left-to-right shunt. A valve-competent but probe-patent foramen ovale may be present in 15–30% of adults. An isolated PFO does not require surgical treatment, although it may be a risk for paradoxical (right to left) systemic embolization.

Neonatal Cold Injury

Neonatal cold injury usually occurs in abandoned infants or those in inadequately heated homes during damp cold spells when the outside temperature is in the freezing range .

Clinical Features:
The initial features are apathy, refusal of food, oliguria, and coldness to touch. The body temperature is usually between 29.5 and 35°C (85–95°F), and immobility, edema, and redness of the extremities, especially the hands, feet, and face, are observed. Bradycardia and apnea may also occur. The facial erythema frequently gives a false impression of health and delays recognition that the infant is ill. Local hardening over areas of edema may lead to confusion with scleredema. Rhinitis is common, as are hypoglycemia and acidosis. Hemorrhagic manifestations are frequent; massive pulmonary hemorrhage is a common finding at autopsy.

Treatment :
Consists of warming and paying scrupulous attention to recognizing and correcting hypotension and metabolic imbalances, particularly hypoglycemia.

Enterobius Vermicularis Infection in Children

ETIOLOGY.
The cause of enterobiasis, or pinworm infection, is Enterobius vermicularis,which is a small (1 cm in length), white, threadlike nematode, or roundworm, that typically inhabits the cecum, appendix, and adjacent areas of the ileum and ascending colon. Gravid females migrate at night to the perianal and perineal regions, where they deposit up to 15,000 eggs.Eggs embryonate within 6 hr and remain viable for 20 days.

MODE OF INFECTION.
Human infection occurs by the fecal-oral route typically by ingestion of embryonated eggs that are carried on fingernails, clothing, bedding, or house dust. After ingestion, the larvae mature to form adult worms in 36–53 days.

PATHOGENESIS.
Enterobius infection may cause symptoms by mechanical stimulation and irritation, allergic reactions, and migration of the worms to anatomic sites where they become pathogenic.

CLINICAL MANIFESTATIONS.
Pinworm infection is innocuous and rarely causes serious medical problems. The most common complaints include itching and restless sleep secondary to nocturnal perianal or perineal pruritus. The precise cause and incidence of pruritus are unknown. They may be related to the intensity of infection, psychologic profile of the infected individual and his or her family, or allergic reactions to the parasite.