Respiratory Anatomy and Physiology

(Riddell, 2000)

THORACIC CAVITY3 sections

Mediastinum

2 Lung Chambers

* because each lung is in a separate chamber the unaffected lung will remain expanded

Right lung has ___ lobesLeft lung has ___ lobesLower lobes or bases are positioned ___________.

(Riddell, 2000)

Surfactant Functions of

surfactant

I. Keeps surface tension lower

II. Allows for Alveolar expansion

III. Prevents collapse of alveoli

(Riddell, 2000)

Processes of RespirationGas exchange occurs in 4 steps:

Ventilation

Diffusion

Perfusion

Diffusion

(Riddell, 2000)

Ventilation

The respiratory control center is located in the ____and ____ of the brain stem (respiratory center).

Autonomic regulation -controlled by ____________

-there are 2 groups of chemoreceptors

1.Central chemoreceptors -sense changes in _________

2. Peripheral chemoreceptors - sense changes in ________

(Riddell, 2000)

Hypoxia

Causes:

Hypoxemic hypoxia

Stagnant or ischemic hypoxia

Anemic hypoxia

Histotoxic hypoxia

(Riddell, 2000)

Signs and Symptoms of HypoxiaAcute Hypoxia Increase in ventilation (Chemoreceptor mediated) Decreases in judgement and motor proficiency Dyspnea, fatigue, headache, nausea, vomiting,

decreased visual acuity Cyanosis of lips and nail beds if adequate

hemoglobin Insomnia and cheyne stokes breathing Disorientation, hallucinations, convulsions with

extreme hypoxia

Chronic Hypoxia Dyspnea, fatigue, cyanosis Pulmonary hypertension (d/t alveolar hypoxia and

vasoconstriction) and polycythemia Body adapts to hypoxia with increased ventilation,

pulmonary vasoconstriction, and increased production of RBC’s

(Ignativicius & workman, 2002)

Adventitious Sounds

additional breath sounds superimposed on normal sounds

indicate changes in the tracheobronchial tree

vary in pitch, intensity, duration, and the phase of the respiratory cycle

Examples: crackle, wheeze, rhonchus, pleural friction rub

(Ignatavicius & Workman, 2002)

Voice Sounds-vocal resonance is increased when the sound must travel through a ________________

(i.e. consolidated area of the lung, pneumonia, atelectasis, pleural effusion, tumor, or abscess)

Bronchophony - assess by having client repeat

the __________ while auscultatingWhispered Pectoriloquy

-perceived by having the client whisper ____________Egophony

- assess by having client repeat the letter __-listen for an _______

(Riddell, 2000)

Abnormal Rates and Rhythms

Bradypnea

Tachypnea

Hypoventilation

Hyperventilation

Cheyne Stokes

Ataxic Sighing

Obstructive

(Riddell, 2000)

Arterial Blood Gases

NormalpH pO2pCO2 HCO3Base excess 0

(+2 alkalosis, -2 acidosis)SaO2

Respiratory Acidosis (pH<7.35, pCO2>50mmHg)

Respiratory Alkalosis (pH>7.45, pCO2<35mmHg)

Metabolic Acidosis

Metabolic Alkalosis

(Riddell, 2000)

Interpreting ABGsAsk yourself these questions…1. pH—acidotic or alkalotic?2. PaCO2—low or high?-respiratory3. Normal & HCO3 low or high with a

normal PaCO2?--metabollic • pH is low (acidosis)• pH is normal or high (alkalosis)• PaCO2 is low (alveolar hyperventilation)• PaCO2 is normal or high (alveolar

hypoventilation)• pH is low and PaCO2 is normal-

consider metabolic causes—low pH and HCO3 less than 22-metabolic acidosis

• pH is high and PaCO2 is normal-consider metabolic causes

• high pH and HCO3 greater than 26-metabolic alkalosis

(Riddell, 2000)

References

Ignatavicius, D. D. & Workman, M. L. (2002). Medical-surgical nursing: Critical thinking for collaborative care. Saunders: PA

Riddell, K. (2000). Windsor Regional Hospital.