Question

A 70 year-old patient, Nick O'Steen, arrived at the hospital emergency room in worse shape than usual. His history included multiple hospital admissions over the past several years for illness associated with his 2 pack a day smoking habit which he started as an 18 year old in the United States Army. No one knew the dangers of smoking in 1956 when many young men picked up the habit and Nick often wished he had never started.

On this admission to the hospital Nick's dyspnea was more pronounced and he had additional symptoms. He was febrile, with a temperature of 102 degrees and a constant cough. His respiratory distress was such that he was using the accessory muscles of inspiration to breathe. Cyanosis was present in his nail beds and his lips.

Diagnostic findings at the time of admission revealed the following:

Arterial blood gases (ABG's) and chemistry

pH 7.25

PCO2 90 mm Hg

PO2 30 mm Hg

O2 saturation 58%

HCO3 38 meq/L

Vital signs:

BP 200/140

HR 140/min

Respiratory rate: 45/min and labored

Tidal volume 200 ml

A chest x-ray showed hyperinflated lungs with consolidation of fluid in the lower lobes bilaterally. A sputum specimen revealed thick green sputum and streptococcal infection.

His pulmonologist was called and provided Nick's baseline normal values for his ABG's blood work and normal physical findings from his records:

pH 7.44

PCO2 65mm Hg

PO2 45 mmHg

O2 saturation 80%

HCO3 42 meq/L

BP 160/120

HR 110/min

Additionally, the following spirometry results were provided as Nick's normal baseline values:

Respiratory Rate 30/min

Tidal Volume 300 ml

Vital capacity 1.2 liters

Residual Volume 3.8 liters

FEV1: 400 ml

FEV3: 600 ml

Mr. O'Steen was admitted to intensive care and started on aggressive respiratory therapy, antibiotics and was given supplemental oxygen at a flowrate of 4 liters per minute by nasal cannula.

1) What primary chronic condition does Nick Have? What information form his baseline findings from his pulmonary physician supports the diagnosis?

2) What secondary acute condition does Nick have? What findings support that diagnosis?

3) What changes in the respiratory system from his primary condition make him more susceptible to develop the acute condition?

4) What accessory muscles of respiration was Nick likely using? With the diaphragm compromised due to the hyperinflation of his lungs, how do the accessory muscles help with pulmonary ventilation?

5) what homeostatic mechanism was contributing to his hypertension and tachycardia and why?

6) What is cyanosis and what was causing it when his O2 saturation was 58%, but not when it was 80%

Answer 1

Q1. Frim the baseline PFT

FEV1/FVC =400/1200=33% Only.

This is obstructive lung disease. From baseline values it is also evident that Nick normally hyperventilates. He is chronically hypercapnic and hypoxic and has hyperinlatted lung fields. Nick also has a long history of significant smoking.

So his primary condition is suggestive of Chronic obstructive pulmonary disease(COPD)

2. Over and above COPD Nock also developed Acute infective exacerbation due to to lower respiratory tract infection.(Strptococal pneumonia)

Its evident from greenish sputum

Strepto infection

Severe acidosis due to sepsis

Bibasal consolidation

Q3. His low breathing reserve , poor pulmonary toilet, emphysematous changes and weak muscles make him more susceptible.

4. Nick was using Trapezius, Sternocleidomastoid, Scalene muscles, Serratus etc as accessory muscles.