Chest Wall Disorders

Question 1

Chest wall disorders causes ___ (restriction or obstruction

Answer 1

restriction

Question 2

a pulmonary restriction results in ___ in lung volumes. There are two broad ways of restriction:

1. stiffening of resp system
2. inability to expand normal lungs.

outline the reasons for each

Answer 2

1. stiffening of resp system; chest wall disorders and interstitial lung disease
2. inability to expand normal lungs
   - neuropathies
   - spinal injuries
   - myopathies

Question 3

overall;

Question 4

what is kyphoscoliosis

Answer 4

an idiopathic paralytic/neurogenic disease that causes twisting. Results in respiratory compromise.

seen more in girls than boys

Question 5

T/f the P/V curve changes with kyphoscoliosis

Answer 5

false. the total lung capacity/overall volume is reduced by the P/V is still proportional.

the CW is displaced to the right though– it is stiffer and the pt has to exert more pressure to expand the chest wall, causing overall respiratory curve to be pushed to the right.

• ALSO, DEAD SPACE IS PRESERVED IN CWDs

Question 7

in CWDs, the flows are ___, but normal when corrected for ____

Answer 7

flows are reduced but normal when corrected for absolute lung volume

Question 8

how is DLCO affected in CWDs

Answer 8

DLCO (diffusion capacity) is reduced because of the reduction in lung volume (area for diffusion). Recall that diffusion is directly related to Volume and inversely proportional to thickness.

Question 9

T/F DLCO is better in chest wall disordrs vs interstitial lung disease.

Answer 9

true.

Ratio of DLCO (% predicted) / FVC
(% predicted) usually is <1 in
interstitial lung disease

• In chest wall disorders, DLCO is
relatively preserved, ratio usually ≥1

Question 11

people with CWDs may have ____- sided heart failure

Answer 11

a low PAO2 causes hypoxic vasconstriction as a reflex to attempt to match circulation/ventilation to maximum gas exchange.

• O2 therapy may prevent core pulmonale and RIGHT sided heart failure.

Continuous vasocontriction puts increase strain on right side of the heart (higher pressures in the pulmonary vessels), requiring the RS to pump harder to get the same amount of blood through the smaller tubes/against more resistance. this causes HYPERTROPHY of the right sided heart, which leads to core pulmonale and eventual right heart failure.

Question 12

how can we help people with kyphoscoliosis achieve better sleep?

Answer 12

nocturnal ventilatory support?

Question 13

in ankylosing spondylitis, the ventilation is primarily ____. Respiratory failure is rare since thoracic lung volume is relatively maintained, with the exception being after ____

Answer 13

in ankylosing spondylitis, the ventilation is primarily ABDOMINAL. Respiratory failure is rare since thoracic lung volume is relatively maintained, with the exception being after ABDOMINAL SURGERY because they won’t be able to abdominally ventilate

Question 14

Outline the changes in TLC, FRC and RV in AK and kyphoscoliosis

Answer 14

TLC is higher in AK which is why resp failure chances are lower in AK compared to KS

Question 15

The P/V is ___ in people with obestiy, but there is a ___ shift in chest wall curve because of the extra mass loading on the thorax, and a reduction in compliance. This results in a reduction in the _____.

Answer 15

The P/V is normal in people with obestiy, but there is a right shift in chest wall curve because of the extra mass loading on the thorax, and a reduction in compliance. This results in a reduction in the functional residual capacity.

in obesity, Breathing at a lower lung volume, airway closure, areas of low V/Q, hence hypoxemia even if lung function is normal

Question 17

explain how the level of spinal cord injury will affect respiratory function

Answer 17

• Effects on respiratory function depend on
level of injury

• Phrenic nerve derived from C3, C4 & C5

• Injury above C3 immediately develop
respiratory failure & will not survive
without artificial ventilation

• C3-C5 variable effect, most require
artificial ventilation temporarily
• Most injuries (MVAs whiplash)
occur at C5-C6 • Spare phrenic nerve • Intercostal muscles affected • Abdominal muscles affected • Expiratory muscles are affected & interfere with ability to cough

Question 20

ALS results in the progressive loss of ____. Outline its natural history

Answer 20

• Amyotrophic lateral sclerosis (ALS)
• Progressive loss of motoneurons
• Sensory, autonomic nerves not affected

• Usually starts peripherally, progressive weakness,
atrophy, fasciculations

• Distal weakness, progressive, progresses
proximally, bulbar/respiratory affected late

Question 21

people with the bulbar variant results in difficulty speaking, swallowing,
aspiration, recurrent aspiration pneumonia and they die from:

Answer 21

Death due to respiratory failure 20 to
pneumonia

Question 22

T/F people with neuromuscular CWDS complain of dyspnea

Answer 22

usually no. the ability to exert themselves to the point of feeling dyspnic is limited by muscle weakness. Difficulty swallowing, choking and recurrent pneumonia is more common.

Question 23

How does ALS affect cough reflex

Answer 23

normally, high pleural pressure against closed glottis. in ALS, they cannot generate the high pressures as usual, secretions are harder to get rid of. Increased risk of atelectasis and pneumonia

Question 24

treatment for ALS

Answer 24