Respiratory pathophysiology 7 Flashcards by Hannah Garrison

Here are the best predictors of postoperative pulmonary complications for patients undergoing pulmonary surgery:

FEV1 <40% predicted
DLCO <40% predicted
VO2 max <15 mL/kg/min

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___________ is indicated when preoperative assessment suggests an increased risk of postoperative pulmonary complications

Split lung V/Q function testing

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Absolute indications for one-lung ventilation include

infection
massive hemorrhage
bronchopleural fistula

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Relative indications for one-lung ventilation include

improved surgical exposure
pulmonary edema
severe hypoxemia d/t lung disease

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Ideal DLT sizing for females is

35-37 French

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Ideal DLT sizing for males is

39-41 French

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DLTs should not be used for

children under 8 years of age

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Options for OLV in children under 8 include

a bronchial blocker or single lumen tube advanced into the main bronchus

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Double-lumen ETTs can be

left or right sided

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A __________ double-lumen is typically preferred

left

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A right-sided DLT may be best in the following situations:

left main bronchus has distorted anatomy (tumor, TAA)
surgical procedures including left pneumonectomy, left lung transplant or left sleeve resection

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Tests for pulmonary surgery address these 3 things:

lung parenchymal function (gas exchange)
respiratory mechanics (airflow)
cardiopulmonary reserve

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A 35 french tube is indicated for

females <160 cm

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A 37 French tube is indicated for

females >160 cm

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Insertion depth of a DLT for females is

27 cm

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A 39 French tube is indicated for

males <170 cm

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A 41 French tube is indicated for

males >170 cm

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Insertion depth of a DLT for males is

29 cm

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The best size DLT for an 8 year old is

26 French

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The best size DLT for 10 years old and up is

28-32 French

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During anesthesia in the lateral decubitus position, the non-dependent lung is

better ventilated and the dependent lung is better perfused (V/Q mismatch)

During one-lung ventilation, there’s a mixing of blood from the non-dependent (non-ventilated) lung and the dependent (ventilated) lung, this leads to

increased shunt fraction and is a significant source of hypoxemia

Suggestions for initiating OLV include:

FiO2 100%
Vt: 6-8 mL/kg IBW
RR: 12-15 breaths/min.
ARM before starting OLV
assess serial ABGs after OLV is started
Consider PEEP 5-10 cmH2O
adjust the I:E ratio if the pt. has an expiratory air flow limitation
Consider TIVA vs. volatile anesthetic

Stepwise approach to hypoxemia during OLV:

verify delivery of 100% oxygen
check the position of tube/bronchial blocker via fiberoptic bronchoscopy
R/o physiologic causes of hypoxemia, such as reduced CO, bronchospasm, mucus plug, pneumothorax
Apply CPAP to the non-dependent lung or use a suction catheter to insufflate O2
Apply PEEP 5-10 cmH2o to dependent lung

If the stepwise approach to hypoxemia for OLV didn't work, the options include

intermittently reinflate the non-dependent lung ligate the pulmonary artery eliminate drugs that inhibit hypoxic pulmonary vasoconstriction

If the DLT is in too far, the

upper lobe is not ventilated (increased risk of hypoxemia)

If the DLT is not deep enough,

there will be failure to achieve lung separation

If the DLT is in the wrong bronchus, the

wrong lung collapses

Is hypoxemia during OLV more common during surgery on the right or left lung?

right lung- the left lung is smaller than the right so there's less surface area for gas exchange when the left lung is ventilated (during right lung surgery)

Unlike a DLT, the bronchial blocker CANNOT (select 3): a. insufflate oxygen into the isolated lung b. ventilate the isolated lung c. provide lung separation in the patient requiring nasotracheal intubation d. prevent contamination from contralateral lung infection e. provide lung separation in children f. suction secretions from the isolated lung

b. ventilate the isolated lung d. prevent contamination from contralateral lung infection f. suction secretions from the isolated lung

A bronchial blocker placed through

a single lumen endotracheal tube is an alternative method of providing OVL

An advantage of the bronchial blocker is that the patient won't need

to be reintubated with a single lumen ETT if he requires postoperative ventilation

Downsides of a bronchial blocker include

the operative lung is slow to collapse (b/c the lumen of the BB is narrow) high-pressure balloon can easily slip to enter the trachea which can lead to contamination and even block ventilation of both lungs

Examples of why you would use a bronchial blocker instead of a DLT include:

children <8 years old patient requires nasotracheal intubation patient has a tracheostomy there's already a SL ETT in place patient requires intubation after surgery & want to avoid changing the DLT

Several types of bronchial blockers include

EZ Cohen Arndt Uniblocker

Identify the MOST common serious complications of mediastinoscopy (select 2): a. chylothorax b. pneumothorax c. left recurrent laryngeal nerve injury d. hemorrhage

b. pneumothorax d. hemorrhage

Mediastinoscopy is performed to

diagnose and stage lung cancer

The most common serious complications of mediastinoscopy include

hemorrhage (#1) & pneumothorax (#2)

An absolute contraindication to mediastinoscopy is

previous mediastinoscopy (d/t scarring)

Since hemorrhage is a risk with mediastinoscopy, it is necessary to have

large bore IV access and PRBCs available

Compression of the innominate artery with mediastinoscopy can

impair cerebral perfusion (right side of the circle of Willis)

Where you place your monitors is important for monitoring

compression of the innominate artery pulse oximeter & arterial line on RUE

If the scope compresses the innominate artery, the

waveform of the pulse ox or arterial line will dampen or disappear

There is an association between oat cell carcinoma and

Eaton-Lambert syndrome

Patients with Eaton-Lambert syndrome are sensitive to

both succinylcholine and non-depolarizers

Indications for tracheal resection include

tracheal stenosis tracheomalacia tumor vascular lesions congenital malformations

To reduce tension on the tracheal anastomosis, the patient's

neck must maintain a flexed position for several days after surgery

The best choice if a patient needs to be reintubated postoperatively after a tracheal anastomosis is

flexible fiberoptic bronchoscopy

Vital structures at risk for injury during mediastinoscopy include

thoracic aorta (hemorrhage and reflex bradycardia) innominate artery (decreased carotid & cerebral blood flow) vena cava (hemorrhage) trachea (airway obstruction) thoracic duct (chylothorax) phrenic and recurrent laryngeal nerve (paresis)

Relative contraindications to mediastinoscopy include

tracheal deviation thoracic aortic aneurysm superior vena cava obstruction

A complication of neck hyperflexion is

tetraplegia