Nursing Care of Clients with Altered Ventilatory Functions

Comprehensive review flashcards covering respiratory system anatomy, function, assessment, diagnostics, capnography, PFTs, ABGs, oxygen therapy, thoracic surgeries, and lung transplantation.

What are the primary functions of the respiratory system?

Olfaction, humidification, $O_2$ supplier, passageways, gas exchange, regulation of pH, voice production, and innate immunity.

Which anatomical structures comprise the upper respiratory system versus the lower respiratory system?

Upper Respiratory System: Nose (paranasal sinuses, turbinates/conchae bullosa), pharynx, tonsils, adenoids, larynx, and epiglottis. Lower Respiratory System: Trachea, main bronchi, lungs, bronchial tree, and alveoli.

What is Tidal Volume (TV) and what is its average value in normal quiet breathing?

Tidal Volume is the amount of air inhaled or exhaled during normal quiet breathing, with an average value of approximately $500\,mL$.

What is Inspiratory Reserve Volume (IRV) and what is its average value?

Inspiratory Reserve Volume is the extra air that can be inhaled forcefully after a normal inspiration, with an average value of approximately $3,000\,mL$.

What is Expiratory Reserve Volume (ERV) and what is its average value?

Expiratory Reserve Volume is the extra air that can be exhaled forcefully after a normal expiration, with an average value of approximately $1,200\,mL$.

What is Residual Volume (RV), its average value, and its primary physiological function?

Residual Volume is the air remaining in the lungs after maximal exhalation (average value $\sim 1,200\,mL$) which cannot be expelled and functions to prevent lung collapse.

How is Vital Capacity (VC) calculated and what is its average value?

$VC = TV + IRV + ERV$, with an average value of approximately $4,700\,mL$. It is measured via spirometry and is decreased in restrictive lung disease.

What is Total Lung Capacity (TLC) and its formula?

$TLC = TV + IRV + ERV + RV$, with an average value of approximately $6,000\,mL$.

What are the early, intermediate, and late signs of respiratory distress and hypoxia?

Early signs: Restlessness, tachypnea, tachycardia. Intermediate signs: Use of accessory muscles, nasal flaring, confusion. Late signs: Cyanosis, bradycardia, decreased level of consciousness (LOC).

What is the normal reference range for End-Tidal $CO_2$ ($EtCO_2$) in capnography?

$35\text{--}45\,mmHg$. Values $> 45\,mmHg$ indicate hypercapnia (hypoventilation), while values $< 35\,mmHg$ indicate hypocapnia (hyperventilation or decreased metabolism).

What clinical conditions produce the abnormal capnogram waveforms shown in the diagram?

1. Obstructive Airway Disease (Asthma, COPD, Bronchospasm): Steep/slow upstroke, rounded plateau.
2. Hypoventilation (Drug Overdose, Sedation, Head Injury): High amplitude, wide plateau.
3. Hyperventilation (Anxiety, Fever, Metabolic Acidosis): Low amplitude, rapid/short cycles.
4. Rebreathing ($CO_2$ Absorber Failure, Faulty Circuit): Elevated baseline, upward shift.
5. Curare Cleft (Spontaneous breathing against ventilator, Muscle relaxant wear-off): Cleft/dip in Phase III plateau.
6. Esophageal Intubation (Misplaced Endotracheal Tube): Initial small peaks followed by flat baseline.

What PFT cutoff values define obstructive versus restrictive lung diseases?

Obstructive: $FEV_1/FVC$ ratio $< 70\%$. Restrictive: Total Lung Capacity (TLC) or Residual Volume (RV) $< 80\%$ of predicted values.

What level of Pulmonary Capillary Wedge Pressure (PCWP) indicates a risk of pulmonary edema?

A PCWP $> 20\,mmHg$ indicates a risk of pulmonary edema.

What safety precautions must be taken regarding balloon inflation during PCWP monitoring?

Inflate the balloon only as ordered using $\le 1.5\,mL$ of air to avoid overinflation, and never leave the balloon inflated due to the risk of pulmonary infarction.

Why is screening an ECG for Left Bundle Branch Block (LBBB) essential before a pulmonary angiogram?

Because catheter passage through the right heart carries a risk of inducing complete heart block in patients with pre-existing LBBB.

What are Light's Criteria for identifying an exudative pleural effusion?

An effusion is an exudate if it meets any of the following:

1. Pleural Fluid Protein / Serum Protein ratio $> 0.5$
2. Pleural Fluid LDH / Serum LDH ratio $> 0.6$
3. Pleural Fluid LDH $> 2/3$ upper limit of normal serum LDH.

What is the primary pathophysiological difference between transudative and exudative pleural effusions?

Transudate: Caused by systemic factors altering hydrostatic pressure (e.g., CHF) or oncotic pressure (e.g., cirrhosis, nephrotic syndrome). Exudate: Caused by local pleural disease resulting in increased capillary permeability (e.g., pneumonia, malignancy, infection) or impaired lymphatic drainage.

What are the core reference ranges for Arterial Blood Gas (ABG) parameters?

pH: $7.35\text{--}7.45$$PaCO_2$: $35\text{--}45\,mmHg$$HCO_3^-$: $22\text{--}26\,mEq/L$$PaO_2$: $80\text{--}100\,mmHg$$SaO_2$: $> 95\%$

How does the ROME mnemonic guide ABG interpretation?

Respiratory Opposite: When pH and $PaCO_2$ move in opposite directions, the disturbance is respiratory. Metabolic Equal: When pH and $HCO_3^-$ move in the same direction, the disturbance is metabolic.

How do Endotracheal Tubes (ETT), Laryngeal Mask Airways (LMA), and Tracheostomies compare in location and vocal cord placement?

ETT: Inserted through mouth/nose, passes THROUGH vocal cords into the trachea. LMA: Inserted through mouth, sits ABOVE vocal cords over the laryngeal inlet. Tracheostomy: Enters the trachea directly THROUGH a surgical stoma in the neck (does not pass vocal cords).

Which oxygen delivery system provides a fixed and precise $FiO_2$ ideal for COPD patients?

The Venturi Mask delivers a fixed/precise $FiO_2$ ($24\text{--}50\%$) at a flow rate of $2\text{--}15\,L/min$.

What flow rate and delivered $FiO_2$ are provided by a Non-Rebreather Mask (NRM)?

Flow rate: $12\text{--}15\,L/min$; Delivered $FiO_2$: $80\text{--}100\%$.

What is the structural difference between a Lobectomy and a Pneumonectomy?

Lobectomy: Surgical removal of one lobe of a lung. Pneumonectomy: Surgical removal of an entire lung.

How does a Wedge Resection differ from a Segmental Resection (Segmentectomy)?

Wedge Resection: Non-anatomical removal of a small, wedge-shaped portion of lung tissue. Segmental Resection: Anatomical removal of a specific bronchopulmonary segment along with its corresponding segment bronchus and blood vessels.

What are the contrasting goals of Pleurectomy/Decortication versus Lung Volume Reduction Surgery (LVRS)?

Pleurectomy / Decortication: Goal is to free a lung trapped by a thick, diseased outer pleural layer (e.g., empyema, fibrothorax). Lung Volume Reduction Surgery (LVRS): Goal is to improve breathing mechanics by surgically removing hyperinflated, non-functioning lung tissue (e.g., severe emphysema/COPD).

What is Primary Graft Dysfunction (PGD) following lung transplantation?

PGD is an acute lung injury occurring shortly after lung transplantation caused by ischemia-reperfusion injury, presenting similarly to acute respiratory distress syndrome (ARDS).

What is Bronchiolitis Obliterans Syndrome (BOS) in the context of lung transplantation?

BOS is an important phenotype of Chronic Lung Allograft Dysfunction (CLAD) characterized by a progressive, irreversible decline in pulmonary function.