Respiratory pathophysiology 5 Flashcards
Examples of antacids used for aspiration prophylaxis include
sodium citrate
sodium bicarbonate
magnesium trisilicate
Examples of H2 antagonists used for aspiration prophylaxis include
ranitidine
cimetidine
famotidine
Examples of GI stimulants used for aspiration prophylaxis include
metoclopramide
Examples of proton pump inhibitors used for aspiration prophylaxis include
omeprazole
lansoprazole
pantoprazole
Examples of antiemetics used for aspiration prophylaxis include
droperidol
ondansetron
Treatment for aspiration includes
tilt the head downward or to the side (first action)
upper airway suction to remove particulate matter
lower airway suction is only useful for removing particulate matter
secure the airway to support oxygenation
PEEP to reduce shunt
bronchodilators to reduce wheezing
IV lidocaine to reduce the neutrophil response
steroids probably don’t help
Abx only if the patient develops a fever or an increased WBC count >48 hrs.
Early signs of vAP include
presence of leukocytosis (high white blood cell count)
fever
increased secretions
increasing O2 requirements
Methods to reduce the incidence of VAP include
hand washing
HOB >30 degrees
daily spontaneous breathing trials
limit sedation
oropharyngeal decontamination
subglottic suctioning
What are the 3 types of pneumothorax?
closed
communicating
tension
The hallmark characteristics of tension pneumothorax include
hypoxemia
increased airway pressures
tachycardia
hypotension
elevated CVP
How does pneumothorax appear on POCUS?
will reveal a lung sliding and the absence of comet tails
If you suspect a pneumothorax, you must discontinue
nitrous oxide immediately
Emergency treatment of a tension pneumothorax includes
insertion of a 14 g angiocath into the 2nd intercostal space at the mid-clavicular line or the 4th or 5th intercostal space at the anterior axillary line
Flail chest is a consequence of
blunt chest trauma with multiple rib fractures
The key characteristic of flail chest is
a paradoxical movement of the chest wall at the site of the fractures
Consequences of flail chest include
alveolar collapse
hypoventilation
hypercarbia
hypoxia
Treatment of flail chest includes
reducing pain (epidural or intercostal nerve blocks)
some patients may require mechanical ventilation and surgical fixation
Closed pneumothorax is a defect in the
pulmonary tree or lung tissue and air enters and exits the pleural space through the defect
no communication between the pleural cavity and atm
Treatment of a closed pneumothorax includes
observation
catheter aspiration
chest tube insertion
With an open pneumothorax the defect is in the
chest wall and air passes between the pleural space and the atmosphere
With an open pneumothorax the lung ____________ on inspiration and ____________ on expiration
collapses; partially re-expands
Treatment of open pneumothorax includes
an occlusive dressing that does not let air in but allows air to escape
supplemental O2
chest tube insertion
possibly tracheal intubation
A tension pneumothorax can occur with
a closed or open defect
Pneumothorax can occur after
central line insertion
supraclavicular, interscalene, and intercostal nerve blocks
barotrauma, high peep, or high peak inspiratory pressures
lung cysts and bullae can expand and rupture when nitrous oxide is used
surgical procedures
chest trauma
_______________ following chest trauma should raise suspicion about a pneumothorax
Increasing peak inspiratory pressures
Surgical procedures that can cause pneumothorax include
radical neck dissection
shoulder arthroscopy
mastectomy
axillary lymph node dissection
mediastinoscopy
laparoscopy
nephrectomy
What are other substances that don’t belong in the chest?
chylothorax
hemothorax
fibrothorax
pyothorax (empyema)
pleural effusion
A chylothorax is
lymph
A hemothorax is
blood
A fibrothorax is
organized blood clot
A pyothorax is
pus
Hemothorax is most commonly caused by
bleeding intercostal vessels
Indications for thoracotomy in the setting of a hemothorax include
initial drainage >1000 mL
continued bleeding >200 mL/hr.
white lung on CXR
large air leak
Hemodynamically stable patients wit a hemothorax and bleeding <150 mL/hr may be managed with
VATS
______________ can cause chylothorax
injury to the thoracic duct during CVL insertion (subclavian> internal jugular insertion)
Injury to the thoracic duct is more likely on
the left side
When a gas embolism of significant size travels to the right heart, it can lodge in the
pulmonary outflow tract or pulmonary artery where it can produce an airlock that converts distal alveolar units to dead space
The incidence of VAE varies with
patient position
Patient positions that are highest to lowest risk for VAE include
sitting> supine> prone> lateral
__________ the most sensitive diagnostic tool of venous air embolism
TEE
Signs and symptoms of VAE include
air observed on TEE
“mill wheel” murmur on precordial doppler
decreased EtCO2
increased EtN2
hypotension
dysrhythmias
hypoxia
cyanosis
CV collapse
Treatment of VAE includes
100% O2
flooding the surgical field
discontinuing insufflation
employing the Durant maneuver (left lateral decubitus position)
Consequences of air trapped in the pulmonary circulation icnlude
increased pulmonary artery pressure
increased RV stroke work index
right ventricular failure
decreased pulmonary venous return
decreased left ventricular preload
decreased CO
asystole and CV collapse
Most sensitive indicators of VAE from most to least include
TEE, precordial doppler, EtCO2, CVP, EKG/BP
