MANAGEMENT OF ILLNESSRESPIRATORY

PURPOSE OF THE RESPIRATORY SYSTEM

• Provide oxygen for metabolism in the tissues and to remove carbon dioxide (the waste product of metabolism)

• Gas Exchange

PHYSIOLOGIC FUNCTION

•During inspiration, the diaphragm contracts, the chest wall expands and the volume of the lungs increases. Gas flows from the atmosphere into the lungs and oxygen diffuses into the blood at the alveolar-capillary interface.

PHYSIOLOGIC FUNCTION

•During expiration the diaphragm and the chest wall relax, thoracic volume decreases, intrathoracic pressure increases, and gas flows out.

PHYSIOLOGY• Wedge pressures (MAP, systolic, diastolic)-

catheter in pulm. Artery branch measuring left atrial pressure. Average is 20mmHg for syst., 10mmHg for dias., mean pressure overall of 15mmHg.

• Increase in hematocrit of 40% increases blood viscosity thus leading to increased pulm. Vascular resistance (cyanotic heart disease)

• Resistance is also seen with a decrease in number of vessels- (hypoplasia, cystic changes)

ANATOMY•The upper respiratory tract (or upper airway) consists primarily of the nose and pharynx

ANATOMYThe lower respiratory tract• Trachea• Two mainstem Bronchi

• Lobar Bronchi• Bronchioles• Alveolar ducts• Alveoli

ANATOMY•The alveoli are the final branchings of the respiratory tree and act as the primary gas exchange units of the lung.

EMBRYOLOGY OF RESPIRATORY TRACT

• Lung:• Conception to 16weeks gestation- lungs are just buds on

the primitive gut and start to divide, larynx develops between wks. 7-10

• 16-24 wks: at 18wks- some of the cells become type II (important for surfactant synthesis)

• 24 wks to birth- 26wks alveolar ducts appear, 30wks alveoli and capillaries appear, cells differentiate into type 1 & 2 cells

• Birth- first breath is initiated d/t chest recoil after thorax has passed through birth canal (pressure).

• Afterbirth- airway dimensions will continue to increase until about 8 yrs. –adult chest wall configuration not reached until age 3.

EMBRYOLOGY OF RESPIRATORY TRACT

• Nose• Nasal cavities form around 4 wks. Obligatory nose-

breathers until 6mons d/t obstruction encountered by elongated esophagus touching the soft palate. By 6mos the larynx grows thus minimizing mouth breathing.

• Pharynx• About 4wks begins to establish structure

• Larynx• Vocal cords appear at 8wks

• Trachea• Begins development at 24 days

AIRWAY RESISTANCE• Airway resistance (the effort or force required to move air into the lungs) is greater in children than in adults because children’s airways are narrower than those of adults.

• When there’s edema or swelling in the airway due to an irritant or infectious process, the airway is further narrowed, increasing the airway resistance even more.

AIRWAY RESISTANCE

• Increased airway resistance makes the child work harder to breathe and is indicated by:

•Increased respiratory rate

•Retractions•Nasal flaring

ANATOMY• Lung compliance (i.e., lung distensibility) is

affected by surfactant and by the elasticity of lung tissue.

• Surfactant is a complex substance consisting of lipids and proteins, formed by alveolar type II cells (type II pnemocytes). Since surfactant decreases surface tension at the air fluid interface, insufficient surfactant results in atelectasis and decreased lung compliance. Surfactant is necessary for sustained inflation of the lung. Surfactant production increases during the later stages of pregnancy

ANATOMY• The unit of gas

exchange is the alveoli

• Encased in network of pulmonary capillaries where gas exchange takes place by simple diffusion

• Type I (gas exchange) and Type II (surfactant) epithelial cells

RESPIRATORY DISORDERS

BRONCHOPULMONARY DYSPLASIA (BPD)

• BPD is a chronic lung disease characterized by:• Respiratory distress• Oxygen dependency persisting beyond 36 weeks

corrected gestation age• Abnormal chest radiographs• Clinically, O2 dependency at 1 month post natal age

• Mixed disorder:• Obstructive: increased airway resistance• Restrictive: decreased compliance

BRONCHOPULMONARY DYSPLASIACONTRIBUTING FACTORS

• High impaired oxygen concentration: capillary proliferation, interstitial fibrosis

• Positive pressure ventilation with airway damage from high pressure: barotrauma, alveolar over distention

• Prolonged intubation resulting in reduced mucociliary function and increased dead space

• Permissive Hypercapnea

BRONCHOPULMONARY DYSPLASIA CONTRIBUTING FACTORS

• Meconium aspiration• Disruption of surfactant production• PPHN: persistent shunting across the PDA, increased pulmonary vascular resistance, ventilation-perfusion mismatch

• CHF• Pulmonary hemorrhage• Severe neonatal pneumonia• Abnormal inflammatory response to injury

MECONIUM ASPIRATION

BPD SYMPTOMS

• Tachypnea, retractions, FTT, hypoxia, hypercapnia, resp. acidosis, crackling, wheezing on auscultation, bronchospasm

• Can cause SIADH- Na & fluid retention• Pulm. HTN- leading to RV failure, tachycardia,

hepatomegaly, periorbital edema, and S2 gallop rhythm

• HTN d/t increased renin and catecholamine activity• BPD tantrums- irritability, agitation, duskiness,

hypercarbia, hypoxemia (usually during bowel movements)

BPD DIAGNOSTICS

• ABG’s- low O2, increased CO2, and compensated resp. acidosis

• ECG- RV enlargement d/t increase in pulm. Vascular resistance leading to RV afterload

• CXR- scattered infiltrates, atelectasis, hyperinflation, cardiomegaly

• PFT’s- low FRC, increased WOB, higher airway resistance and oxygen consumption,

• Echocardiogram- pulm. HTN, RV enlargement• Cardiac Cath (rare)- FTT or increased pulm. HTN to

determine extent of disease.

BPD MANAGEMENT

• O2 management- supplemental (92%-95%), CPAP at the earliest- may mitigate the need for mech. Ventilation, tracheostomy

• Medication: Bronchodilators (albuterol mainly for acute episodes, anticholinergic (atrovent, steroids, diuretics (SIADH) such as Lasix or Bumex

• Nutrition: enteral feeds preferred• Long-term hospitalization will require monitoring and

follow with speech, PT, OT in order minimize gaps with cognitive and developmental achievements.

TRACHEOESOPHAGEAL FISTULA (TEF)

Two Forms:•Esophageal atresia

•Tracheo-esophageal fistula

TRACHEOESOPHAGEAL FISTULAS (TEF)

• Congenital defect occurring during the 4th week of gestation when the embryonic foregut divides into the trachea, larynx, and lungs anteriorly, and the esophagus posteriorly

• The prenatal history often includes a history of polyhydramnios (inability of the infant to swallow amniotic fluid into the gut)

RELATIVE FREQUENCIES OF OCCURRENCE OF THE VARIOUS TYPES OF ESOPHAGEAL ATRESIA

(EA) WITH AND WITHOUT TRACHEOESOPHAGEAL FISTULA (TEF).

                                                                 

                 FIGURE 4. Relative frequencies of occurrence of the various types of esophageal atresia (EA) with and without tracheoesophageal fistula (TEF).

TEF: PRE-OPERATIVE MANAGEMENT

• Avoid use of pacifiers which will stimulate production of oral secretions

• Prone positioning with an elevated HOB 30 degrees to lessen the chance of aspiration of stomach contents into the lungs via the fistula

• Ensure adequate oxygenation and ventilation: respiratory distress related to gaseous distention of the stomach with impingement on the diaphragm

TEF: PRE-OPERATIVE MANAGEMENT

• Low pressure positive pressure ventilation if needed to avoid gaseous distention of the stomach when there is no outlet for decompression

• Ensure optimal fluid and electrolyte balance: NPO, IVF, TPN

TEF: POST OPERATIVE CARE

• Gastrostomy tube is returned to gravity drainage until the infant can tolerate feedings

• Optimize nutrition: TPN, enteral feeds after evaluation of the esophageal anastomosis

• Pain management

• Gastric decompression: do not manipulate NG tubes placed in surgery

TEF: POST-OPERATIVE MANAGEMENT

• Optimal oxygenation and ventilation:• Mechanical Ventilation is weaned as soon as

possible• ETT suctioning needs to be done with a pre-

measured catheter to only the tip of the ETT to avoid tracheal suture line stress

• Hemodynamic stability: observe for hypovolemia due to 3rd spacing

• Assess the extrapleural chest tube for presence of saliva which may indicate anastomosis leak

CROUP RSV PNEUMONIA

EPIGLOTTITIS PERTUSSIS

ACUTE RESPIRATORY INFECTIONS

ACUTE LARYNGOTRACHEOBRONCHITIS (LTB)

• Most common of the croup syndromes

• Generally affects children younger than 5 years

• Organisms responsible• RSV, parainfluenza

virus, Mycoplasma pneumoniae, influenza A and B

CROUP• Is usually preceded by

an upper respiratory infection that proceeds to laryngitis and then descends into the trachea, causing inflammation of the mucosal lining and subsequent narrowing of the airway.

CROUPPATHOPHYSIOLOGY

• Cricoid cartilage- narrowest segment of the upper airway in infants and small children

• Swelling & secretions lead to increased airway resistance

CROUPCLINICAL

MANIFESTATIONS• Barking cough & hoarseness

• Inspiratory stridor and varying degrees of respiratory distress

• Nasal flaring• Tracheal tugging• Retractions• Low grade fever

CROUPDIAGNOSTIC TESTS

•A/P CXR- “steeple sign”

•Lateral radiograph--normal epiglottis

THERAPEUTIC MANAGEMENT

Airway management• A steamy bathroom at home• In the hospital, hoods for infants or mist tents• Maintain hydration—PO or IV• High humidity with cool mist• Nebulizer treatments

• Racemic Epinephrine (mucosal vasoconstriction)

• Steroids (reduce subglottic edema and inflammation)

CROUPPATIENT MANAGEMENT

• Minimize agitation

• Antipyretics• Enteral feedings• Intubation for severe respiratory distress

A. Sore throat

B. Inspiratory stridorC. Complete obstruction

D. Respiratory tract infection

Nurse Amy is assessing a child with croup in the emergency department. The child has a sore throat and is drooling. Examining the child’s throat using a tongue depressor might precipitate which of the following?

QUESTION

QUESTIONWhich of the following clinical manifestations is an indication of the need for an artificial airway in a 2 y/o child with Laryngotracheobronc-hitis

A. Elevated temperature

B. Increased mucous production

C. Metabolic acidosis

D. Persistent agitation/lethargy

EPIGLOTTITIS• Severe, life-

threatening, rapidly progressive infection of epiglottis

• Usually occurs in children 2-6 years

• Mortality 8-12% of hospitalized children

EPIGLOTTITISCLINICAL MANIFESTATIONS

Four D’s & S•Drooling•Dysphagia•Dysphonia•Distress•Stridor

•Fever with abrupt onset

•Sore throat•Muffled voice•Tripod position

EPIGLOTTITISTripod position

EPIGLOTTITIS DIAGNOSTIC TESTS

• Avoid invasive procedures if epiglottitis is suspected!!

• Lateral neck x-ray- diagnostic

• Blood cultures (once airway is stable)

EPIGLOTTITISPATIENT MANAGEMENT

• Prevention- Hib vaccine

• OR for laryngoscopy & intubation

• Maintain comfort• Intubation** (careful with accidental extubation)

Respiratory Infection

Etiology

Typical Age

Range

Clinical Sympto

ms

Management

Epiglottitis

H-fluBeta-hemolyticStreptococcusPneumococci

2-6 years

Diagnosed with lateral neck film

Abrupt feverDroolingStridorTripod positionThumb sign on x-ray

OR for laryngoscopy and intubation

Maintain Comfort

Sedation

Croup Viral orBacterial

3 months -5 years

Low feverBarking Cough“Steeple sign” on x-ray

Racemic epinephrine

Cool humidified oxygen

BRONCHIOLITIS

• Acute inflammatory disease of the lower respiratory tract

• Results in the obstruction of small airways

BRONCHIOLITIS: PATHOPHYSIOLOGY

• Respiratory syncytial virus (RSV) is the leading cause of bronchiolitis.

• Bronchiolitis occurs when viruses or other infectious agents invade the mucosal cells lining the bronchial and bronchioles, causing the cells to die.

• Cell death results in cell debris that clogs and obstructs the bronchioles and irritates the airway.

BRONCHIOLITIS: PREVENTION

• Preventative therapy may be indicated for RSV bronchiolitis in high risk infants

• Synagis (Palivizumab) is given for 5 consecutive months during RSV season which is between…..

November and April

QUESTION•pH 7.31•pCO2 50•pO2 80•HCO3 22•O2 sat 95%

A 10 month old w/ bronchiolitis is intubated in the EC due to an acute deterioration in her respiratory status. Post intubation ABG follows:

QUESTION CONT.

a. Respiratory acidosis

b. Respiratory alkalosis

c. Metabolic acidosis

d. Metabolic alkalosis

The blood gas reflects:

ABG’SNormal Values:•pH: 7.34-7.45

•pC02: 35-45

•HC03: 22-26

•P02: 80-100

PNEUMONIA• Pneumonia is an acute

inflammation or infection of the respiratory bronchioles, alveolar ducts and sacs, and alveoli (the parenchyma) of the lungs that impairs gas exchange.

PNEUMONIA ETIOLOGY• Infection of the lung usually caused by viruses or bacteria

• Etiologic Agent varies with age

•RSV•Influenza•Paraflu•Streptococci•Staphylococci

PNEUMONIACLINICAL MANIFESTATIONS

• High fever• Cough chest pain

• URI symptoms• Respiratory distress

• Cyanosis• Apnea (infants)

PERTUSSIS• Known as whooping cough- contagious acute respiratory tract infection

• Caused by gram negative coccobacillus Bordetella pertussis

• Transmitted through inhalation of contaminated respiratory droplets or by direct contact with contaminate articles

PNEUMONIA & PERTUSSIS PATIENT MANAGEMENT

• Hydration• Analgesics• Supplemental

oxygen (intubation depending on severity)

• NPO• Steroids• Antibiotics

STATUS ASTHMATICUS

STATUS ASTHMATICUSETIOLOGY

Characterized by:• Airway inflammation•Mucosal edema• Airway plugging• Bronchospasm (mainly smooth muscle )

MECHANISMS OF OBSTRUCTION IN ASTHMA

QUESTION•BP 130/78•HR 68•RR 48•FiO2 0.6•O2 Sat 88%

12 y/o male is admitted to the PICU following an acute asthma attack. He has received multiple albuterol treatments. The following measurements are obtained:

QUESTION (CONT)

a. Wheezing & coughing

b. Coughing & grunting

c. Pleural rub & wheezing

d. Stridor & bronchospasm

Physical findings could include which of the following:

STATUS ASTHMATICUSCLINICAL

MANIFESTATIONS• Respiratory Effort

• Cardiac Output

• Metabolic Acidosis

• Altered LOC

STATUS ASTHMATICUS DIAGNOSTIC STUDIES

•CXR•CBC•ABG•Basic Metabolic Panel

QUESTIONa. Isoproterenol

(Isuprel)b. Methylprednisolo

ne (Solu-Medrol)c. Albuterol

(Ventolin)d. Ipratropium

bromide (Atrovent)

The use of an inhaled beta 2-adrenergic agonist in the management of a child with status asthmaticus would include which of the following medications?

STATUS ASTHMATICUSPATIENT MANAGEMENT

•Continuous Assessment

•Medications•Mechanical Ventilation

•Supportive Care

CYSTIC FIBROSIS

CYSTIC FIBROSIS• Chronic,

autosomal recessive inherited disorder of the exocrine glands that affects multiple organ systems

• Most common lethal, inherited disease of Caucasians of European origin but is found in every ethnic & racial group

CYSTIC FIBROSIS• Exocrine glands are glands that secrete their

products (including hormones and other chemical messengers) into ducts (duct glands) that lead directly into the external environment

• They are the counterparts to Endocrine glands, which secrete their products (hormones) directly into the bloodstream (ductless glands) or release hormones (paracrines) that affect only target cells nearby the release site.

CYSTIC FIBROSIS• Life expectancy for the person with the disease is

around 31-32 years

• The gene responsible for cystic fibrosis is located on chromosome 7q.

• It encodes a membrane associated protein called the cystic fibrosis transmembrane regulator (CFTR)

• Exact function of the gene is unknown, but it appears to help regulate chloride and sodium transport across epithelial membranes.

CYSTIC FIBROSISPATHOPHYSIOLOGY

learn.genetics.utah.edu

www.aurorahealthcare.org

CYSTIC FIBROSISTREATMENT

• Treatment for cystic fibrosis is life long.• Aimed at maximizing organ function and

quality of life & forestalling the complications• Current treatments delay the decline in organ

function

• Targets for therapy - Lungs, GI tract/Nutrition & the Reproductive organs (including Assisted Reproductive Technology (ART)), Transplantation & Gene therapy

Davies J et al. Cystic Fibrosis. BMJ. 2007 Dec 15;335(7632):1255–59.

CYSTIC FIBROSISTREATMENT

- ANTIBIOTICS COVERAGE -

• Based on culture (deep throat/sputum/BAL)• Aminoglycoside + Semisynthetic

PCN/Cephalosporin (SYNERGY testing)• Home/hospital• Minimum of 10 – 14 days or until:

- symptoms resolved- PFT’s (FEV1) within 10% of baseline/higher- suppressed organisms- to avoid resistant bacteria

• Drug levels – Hearing loss( ↑peak) & kidney damage (↑trough)

CORNERSTONES OF PULMONARY MANAGEMENT

• Regular visits to CF Center

• Good nutrition - enzymes replacement in pancreatic insufficiency, Vitamins A,D,E & K ;high-calorie meals

• Anti inflammatory drugs- Steroids (inhaled, oral), Ibuprofen, Macrolides

• Active lifestyle

AEROSOLIZED MEDICATIONS THAT HELP LOOSEN SECRETIONS INCLUDE

• dornase alfa (Pulmozyme®) - recombinant human DNase- breaks down DNA (neutrophils) in

sputum - ↓viscosity17 ; - ↑5- 7% FEV1

• hypertonic saline16 • adrenergic/cholinergic agonists

-improves ciliary motility• N-acetylcysteine (Mucomyst)

- Bad smell

TREATMENT OF AIRWAY INFECTIONS - MECHANICAL TECHNIQUES -

to dislodge sputum and encourage expectoration : - Chest physical therapy - ThAIRapy vest - Intrapulmonary percussive ventilator(IPV) - acapella® (PEP)

Aerobic exercise