Chapter 290 - Disorders of Ventilation

Question 1

arterial level of carbon dioxide is maintained between which values at sea level?

Answer 1

37 - 43 mmHg

Question 2

3 disturbances of PaCO2

Answer 2

altered CO2 production
altered minute ventilation
altered dead space fraction

Question 3

Acute ventilatory disorders are often due to which disturbance?

Answer 3

Altered CO2 production

Question 4

Chronic ventilatory disorders are due to

Answer 4

1. inappropriate levels of minute ventilation

2. increased dead space fraction

Question 5

Acts as the initial integration site for many of the afferent nerves relaying information about Pao2, Paco2, pH, and blood pressure from the carotid and aortic chemoreceptors and baroreceptors to the CNS

Answer 5

Dorsal Respiratory Group

Question 6

Where is the respiratory rhythm generated?

Answer 6

Ventral respiratory group

parafacial respiratory group

Question 7

important for the generation of active expiration

Answer 7

parafacial respiratory group

Question 8

Area responsible for the generation of various forms of inspiratory activity, and lesioning of this area leads to the complete cessation of breathing

Answer 8

pre-Bötzinger complex

Question 9

During normal sleep there is an attenuated response to hypercapnia and hypoxemia resulting in mild nocturnal hypoventilation that corrects upon awakening.

Answer 9

True

Question 10

Hypoventilation disorders result from reduced minute ventilation or increase in dead space. What are the 4 major categories?

Answer 10

1. parenchymal lung and chest wall disease
2. sleep disordered breathing
3. neuromuscular disease
4. respiratory drive disorders

Question 11

This is frequently a sign of reduced respiratory muscle force generation

Answer 11

New onset orthopnea

Question 12

Characteristic sequence of the clinical course of patients with chronic hypoventilation from neuromuscular or chest wall disease

Answer 12

1. Asymptomatic stage
2. Nocturnal hypoventilation
   
   • during REM and later in NREM
3. Daytime Hypercapnia
   
   • VC drops

Question 13

Hallmark of all alveolar hypoventilation syndromes

Answer 13

increase in Alveolar pCO2 and therefore in PaCO2

Question 14

Elevated plasma bicarbonate in the absence of volume depletion is sug- gestive of hypoventilation

Answer 14

True

Question 15

Elevated PaCO2 with a normal pH confirms what condition

Answer 15

CHRONIC alveolar hypoventilation

Question 16

Most frequent sleep disorder leading to chronic hypoventilation accompanied by obstructive sleep apnea

Answer 16

Obesity hypoventilation syndrome

Question 17

Which Questionnaire has been validated in the primary care setting and identifies OSA

Answer 17

Berlin Questionnaire

Question 18

Which questionnaire has been validated as a screening tool for OSA in sleep and surgical clinics.

Answer 18

STOP-Bang

Question 19

treatment of hypoventilation and apneas, both central and obstructive, in patients with neuromuscular and chest wall disorders

Answer 19

Nocturnal non-invasive positive-pressure ventilation (NIPPV)

Question 20

Criteria for using nocturnal NIPPV if symptoms of hypoventilation exist

Answer 20

• Paco2 ≥45 mmHg
• nocturnal oximetry ≤88% for 5 consecutive min
• maximal inspiratory pressure <60 cmH2O
• FVC <50% predicted
• sniff nasal pressure <40 cmH2O.

Question 21

Pharmacologic agents that stimulate respiration, such as medroxy- progesterone and acetazolamide, have been poorly studied in chronic hypoventilation and should not replace treatment of the underlying disease process.

Answer 21

true

Question 22

Diagnostic criteria for OHS

Answer 22

BMI ≥30
chronic daytime alveolar hypoventilation (Paco2 ≥45 mmHg at sea level) in the absence of other known causes of hypercapnia.

Question 23

Treatment of OHS

Answer 23

Weight reduction

NIPPV

Question 24

OHS Treatment reserved for patients not able to tolerate high levels of CPAP support or patients that remain hypoxemic despite resolution of obstructive respiratory events

Answer 24

BIPAP

Question 25

treatment for patients with OHS but with no evidence of OSA

Answer 25

BIPAP

Question 26

Central hypoventilation syndrome presenting later in life or in the neonatal period

Answer 26

Ondine’s curse

Question 27

Abnormalities of which gene have been implicated in the pathogenesis of Congenital central hypoventilation syndrome

Answer 27

PHOX2b

Question 28

anxiety disorders and panic attacks are NOT synonymous with hyperventilation

Answer 28

True

Question 29

Once chronic hyperventilation is established, a sustained increase by how many percent in alveolar ventilation is enough to perpetuate hypocapnia?

Answer 29

10%

Question 30

Overall prevalence of OSA in middle aged men

Answer 30

3-4%

Question 31

Overall prevalence of OS in middle Ged women

Answer 31

2%

Question 32

Chest wall disease

Answer 32

A- abdominal distention
K - Kyphoscoliosis
O - Obesity

Question 33

Impaired Neuromuscular transmission

Answer 33

Myasthenia Gravis
ALS
Phrenic nerve injury
Spinal cord lesion

Question 34

Sleep disordered breathing

Answer 34

Upper airway obstruction

Intermittent hypoxemia

Question 35

Muscle weakness

Answer 35

Myopathy
Malnutrition
Fatigue

Question 36

Diminished drive

Answer 36

Sleep disordered breathing
Narcotic/ sedative use
Brainstem stroke
Hypothyroidism
Primary alveolar hypoventilation

Question 37

In how many percent of cases is sleep

Disordered breathing in the form of OSA

Answer 37

90%

Question 38

In patients with hyperventilation, an initial event leads to increased alveolar ventilation and a drop in PaCO2 to how many mmHg?

Answer 38

20mmHg

Question 39

ABG findings that can confirm chronic hyperventilation

Answer 39

Compensated Respi Alk

Near normal pH
Low PaCO2
Low HCO3