critical care exam 2 pulmonary alterations

inspiration is considered to be _____ while exhalation is considered to be _____

active, passive

what is the size of the right bronchi? angle?

- wider

- 20-30 degrees from midline

because the right bronchi is wider and the angle its in, it is a more common location for what?

- aspiration

- foreign objects

- right main stem intubation

what is the size of the left bronchi? angle?

- narrower

- 45-55 degrees

what is the alveoli? what does it contain and how does it work?

- primary site of gas exchange

- contain surfactant

* phospholipid that helps to keep them from collapsing and keep them stable

how is the lung different from the heart?

doesnt have spontaneous activity or automaticity

what are the lungs controlled by?

brain stem/medulla oblongta (mainly) + pons

what is positive end expiratory pressure (PEEP)? how much do the lungs have?

- pressure that helps keep lungs from collapsing

- lungs have +5 of PEEP

the 2 types of pleura include ____ and _____

visceral, parietal

where is the visceral pleura located?

adheres to lung itself on outer aspect

where is the parietal pleural located?

lines inner surface of chest wall in mediastinum

what is between the visceral + parietal pleura? what does it do?

- small amount of fluid

- keeps lungs from adhering to chest wall

what is intrapulmonary pressure?

amount of pressure INSIDE the lungs

on INHALATION, what kind of intrapulmonary pressure will the lungs have?

NEGATIVE pressure

on EXHALATION what kind of intrapulmonary pressure will the lungs have?

POSITIVE pressure

what is intrapleural pressure?

pressure in pleural space (b/w surface of lung + surface of chest wall)

intrapleural pressure is considered to be _____

ALWAYS NEGATIVE

what happens if intrapleural pressure is positive?

lungs collpase

what is the muscle used for ventilation?

diaphragm

what is ventilation?

air moving in and out of lungs => inhalation + exhalation

what are the properties that affect ventilation?

- elasticity

- compliance

- resistance

- pressure

what is elasticity?

- amount of recoil lungs have after stretching from inhalation

- amount of snapback lungs have after inhalation

how can COPD affect elasticity in lungs? what can it lead to?

- can decrease elasticity

- leads to air trapping

what is compliance?

measures lungs ability to stretch + expand

what happens to ventilation if the lungs have less compliance? example?

- makes it harder to ventilate

- pulmonary fibrosis: tightening of lung tissue => decreases compliance

what is resistance caused by? examples that lead to resistance in ventilation?

- resistance to airflow caused by friction in airways

- bronchospasms: increase resistance in airways

- mucus plug: impacts airway resistance

what is pressure created by in the lungs? what is it controlled by?

- air is taken into passages

- controlled by size of lungs and thorax

what is perfusion (Q)?

Circulation to the vessels and throughout body

ventilation and perfusion must be _______ at alveolar capillary membrane in order to have optimal gas exchange

equally matched

what is the normal ratio of ventilation to perfusion (VQ)?

4:5 L/min -> 0.8 or 80%

what is VQ mismatch?

amount of ventilation or perfusion is NOT NORMAL; no normal ratio

what are the VQ mismatches?

- alveolar dead space

- intrapulmonary shunting

what is alveolar dead space? example where this can be seen?

- occurs when alveoli are receiving ventilation (air moving in + out of alveoli) but there is no perfusion to alveoli

- adequate ventilation, shitty perfusion

- ex. pulmonary embolism

what is intrapulmonary shunting? examples?

- occurs when alveoli are receiving perfusion BUT not receiving ventilation

- adequate perfusion, shitty ventilation cuz not going thru gas exchange

- ex. pulm edema, ARDS, alveolar collapse -> cuz air thats entering lung cant get into alveoli + have gas exchange

what is tidal volume (TV)? equation for TV?

- volume of air exhaled after a normal resting inhalation

- kg (pt weight) x 6-10 mL/kg

normal tidal volume (TV)?

6-10 mL/kg

what is minute ventilation (VE)? what is the equation? what is this an important consideration for?

- measures actual amount of air pt is moving

- TV x RR

- used when deciding if pt can be extubated

normal minute ventilation (VE)?

5-8 L/min

if a pt has a minute ventilation (VE) of 2 L/min and another pt has a VE of 8 L/min, who would have a better chance of being extubated?

the pt w/ a VE of 8L/min

what is total lung capacity (TLC)?

maximum amount of air in lung after maximal inspiration

normal total lung capacity (TLC)?

5.7-6.2 L

what are the 2 vascular systems in pulmonary circulation?

pulmonary and bronchial system

what does the pulmonary system do?

forms gas exchange network that surrounds alveoli

what does the bronchial system do?

provides systemic blood supply to lung tissue itself + perfuses trachea-bronchial tree, visceral pleura, interstitial + connective tissue, and other areas of thoracic cavity

the pulmonary circulation contains _____ lymphatic system

one

what does the lymphatic system do?

- responsible for removing foreign particles + cellular debris

- produces antibody + cell mediated immune responses in lungs

- helps to remove fluid from lungs and keep alveoli clear

what is pulmonary vascular resistance (PVR)?

resistance the right ventricle must overcome to eject blood into the lungs

what is the normal pulmonary vascular resistance (PVR)?

100-250

what things can increase PVR?

- pulm HTN

- anaphylaxis/anaphylactic shock

- hypoxia

- intrapulmonary shunting

- alveolar dead space

how can pulm HTN lead to an increased PVR?

it forces RV to work harder and eventually lead to RV failure

how can anaphylaxis/anaphylactic shock cause increased PVR?

- histamine release + angiotensin II cause vasoconstriction which increases PVR

- airways close which further increase PVR

how does hypoxia lead to increased PVR?

leads to increased PVR thru hypoxic vasoconstriction

most blood vessels _____ in response to hypoxia

dilate

what PaO2 level indicates hypoxic vasoconstriction? how are the pulm vessels affected?

- <60 mm Hmg

- vessels constrict

when does hypoxic vasoconstriction usually occur? How is the body affected? what kind of response is this considered to be and how?

- when a portion of pulm capillaries are perfusing underventilated alveoli

- pulm vessels constrict while the rest of body's vessels dilate

- compensatory response by body thru diverting blood to better oxygenated lung segments

what happens if hypoxia and hypoxic vasoconstriction is prolonged and generalized?

leads to pulm HTN and increased PVR

how can intrapulmonary shunting + alveolar dead space cause increased PVR?

d/t hypoxemia and triggering hypoxic vasoconstriction

what are causes of decreased PVR?

gravity + pulmonary vasodilators

how does gravity lead to decreased PVR?

by sitting pt up they will have better venous return, decreased work of breathing, and lowering PVR

how do pulmonary vasodilators cause decreased PVR?

they specifically target pulm vasculature + dilate pulm arteries to reduce PVR

O2 and CO2 moves throughout the body by ____

diffusion

what does a chest xray do?

- helps detect various disorders and complications, and assists in evaluation of treatment

- helps check for correct placement

what things can be identified on a chest xray?

- dark color

- white color

- white out

- pleural effusion

- atelectasis

- tracheal shift

- ribs

- placement of invasive lines

what does dark color on a chest xray indicate?

air moving thru tissue

what does white color on a chest xray indicate?

not a lot air moving thru tissue and most likely fluid there

what does white out on a chest xray mean? where is this commonly seen in?

- very little air moving thru lungs; lot of fluid in area

- commonly seen w/ ARDS

what is pleural effusion? how does this appear in a chest xray? how do breath sounds on the affected side?

- fluid in pleural space

- on chest xray diaphragm edges blunted/rounded and not sharp

- on affected side will have diminished breath sounds

what is atelectasis? how are breath sounds affected?

- lung lobes that become separated/displaced at fissures

- collapsed area of lung

- if area is collapsed, no breath sounds over that particular area

where can tracheal shift be seen w/ in a chest xray?

seen w/ large pneumothorax, tension pneumo, tumor

why would ribs be looked at in a chest xray?

to evaluate for fractures

what do sputum tests do? where are they done with?

- used to obtain stain + culture in order to look for potential infection or other types of abnormal cells

- done w/ deep cough or suctioning

how does a thoracentesis work?

- needle inserted into pleural space to drain fluid that has accumulated

- fluid then sent for various testing

what criteria would make pts not be able to receive a thoracentesis?

- unstable hemodynamics

- coagulation abnormalities

- mechanical ventilation

- presence of balloon pump

- uncooperative pt

what position should pts be in for a thoracentesis? what should pts avoid doing during the procedure?

- sit on edge of bed w/ hands and arms supported on bedside table

- should avoid moving or coughing

what complications can happen with a thoracentesis?

•Pain

•Pneumothorax

*Re-expansion pulm edema

why does re-expansion pulm edema happen in a thoracentesis?

•d/t increased cap permeability from inflammation

what does the fluid in a thoracentesis get tested for?

various bacteria, fungi, malignancy

what does cloudy fluid from a thoracentesis mean?

some type of bacterial or fungal infection

what is a bronchoscopy and what does it look at? what is required during this procedure?

- flexible semi-rigid scope that used to visualize airways

- looks at larynx, trachea, bronchus, tissue

- sedation required

what other things can be done with a bronchoscopy?

- bronchial washings + biopsies

- removal of mucus plugs + clots

- testing for TB

- looking for cancer, inflammation, foreign objects

when would a bronchoscopy be done to test for TB?

if there is a special deep sputum called AFB present

what complications can happen with a bronchoscopy?

•Laryngospasm, bronchospasms

•Pneumothorax

•Hemorrhage

•Arrhythmias

•Desaturation

•Aspiration pneumonia

what meds are pts premedicated with before a bronchoscopy to prevent larynospasms and bronchospasm?

bronchodilators

what would indicate aspiration pneumonia as a result of a bronchoscopy?

if a pt vomits

what nursing management is done for bronchoscopy?

- making sure pt can swallow before feeding

- watch for desaturation

- watch for s/s of complications

- pt NPO

how long must a pt remain NPO prior to a bronchoscopy? why?

- 6-8 hrs

- to reduce risk of vomiting

what does a spiral CT do?

rotates around to visualize spiral cuts of lung

what is a spiral CT often used to diagnose? when?

- pulm embolus

* when pt cannot tolerate a VQ scan

-> pts on higher amounts of O2

-> pts on ventilator

what is a plain CT used for?

used for diagnosis of suspicious lesions that are hard to assess w/ chest xray

what is a VQ scan? what does it help evaluate for + what does it detect?

- radioactive scan that measures ventilation to perfusion

- helps to evaluate for pulm embolism

- detects defects in pulm vasculature supply

a VQ scan can indicate a low, medium, or high probability of ___

PE

during a VQ scan, for ventilation, pts will _____ radioactive gas. as for perfusion, they will have ______ of radioactive isotope.

inhale, injection

what is D-dimer? is it specific or nonspecific? what is it considered to be?

- lab value that measures inflammation

- nonspecific

-considered GOLD STANDARD for checking for inflammatory process

what is the pH range?

7.35-7.45

pCO2 range?

35-45

HCO3 range?

22-26

PAO2 range?

80-100

what are the compensatory mechanisms used in ABGs?

lungs and kidneys

what are the lungs in charge of removing in relation to ABGs?

in charge of removing CO2

how do the kidneys compensate with ABGs?

- correct acid/base imbalances by binding hydrogen ions w/ CO2 ions to form HCO3(bicarbonate) to buffer acid

- kidneys release hydrogen ions into tubules to buffer alkaline state