Respiratory Distress Flashcards
Hypoxemia results from any combination of five mechanisms
Hypoventilation
Right-to-left shunt
Ventilation-perfusion (V ̇/Q ̇) mismatch
Diffusion impairment
Low inspired oxygen
occurs when blood enters the systemic circulation without traversing ventilated lung
Right-to-left shunt
A hallmark of significant right-to-left shunting is
the failure of arterial oxygen levels to increase in response to supplemental oxygen
increased A-a O2 gradient, and hypoxemia improves with supplemental oxygen
Ventilation-perfusion (V ̇/Q ̇) mismatch
Hypoxemia mechanism in
pulmonary emboli, pneumonia, asthma, chronic obstructive pulmonary disease, and even extrinsic vascular compression
Ventilation-perfusion (V ̇/Q ̇) mismatch
increased Paco2 and a normal A-a O2 gradient
Hypoventilation
A-a O2 gradient is increased, and hypoxemia improves with supplemental oxygen
Diffusion impairment
commonly seen at high altitude (including commercial air travel) or in nonobstructive asphyxia
Low inspired oxygen
True or false
Cyanosis, the blood or tissue discoloration associated with a lowered arterial oxygenation saturation, is not a sensitive or specific indicator of hypoxemia
True
True or false
Hypercapnia never results from increased CO2 production alone
True
Hypercapnia is exclusively caused by______________ and is defined as a Paco2_______ (>6 kPa)
alveolar hypoventilation
> 45 mm Hg
True or false
Do not withhold oxygen required to maintain minimum oxygen saturation levels in any chronic lung disease patient in an effort to stimulate ventilation and reduce hypercapnia
True
Acute cough is cough lasting ____________ and is usually associated with self-limited upper respiratory or bronchial infections
<3 weeks
Subacute cough lasts 3 to 8 weeks and is most commonly ___________
postinfectious
most common causes of chronic cough
(1) smoking, often with chronic bronchitis
(2) upper airway cough syndrome (formerly postnasal discharge)
(3) asthma
(4) gastroesophageal reflux
(5) angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker therapy
Sequential Approach to Chronic Cough
Treatment of Hiccups: Physical Maneuvers
only has U.S. Food and Drug Administration approval for treatment of intractable hiccups
chlorpromazine
True or false
A significant pleural effusion is large enough to produce a pleural fluid strip >10 mm wide on lateral decubitus radiographic views or by US.
True
Therapeutic thoracentesis with drainage of_________ L of fluid is indicated if the patient has dyspnea at rest
1.0 to 1.5
Acute drainage of larger volumes is associated with________________, so large- volume drainage is to be avoided
reexpansion pulmonary edema
Optimization of medical therapy typically resolves_____ of effusions due to heart failure within 2 weeks
> 80%
Cytology for malignancy: highest yield is with
adenocarcinoma
massive hemoptysis definition
ranges from
100 mL per 24 hours
to
> 1000 mL per 24 hours
midpoint value of 600 mL per 24 hours accepted by many
__________ accounts for only 1% of the blood flow to the lungs but 90% of the cases of hemoptysis because it is a high-pressure system
bronchial arteries
Rasmussen’s aneurysm
is a false aneurysm of dilated blood vessels crossing the wall of a tuberculosis cavity.
