Respiratory emergencies QUIZ Wk10 Flashcards
3 types of pneumothorax
Closed, open, tension(needle decompression)
What is a pleural effusion
Abnormal accumulation of fluid in pleural cavity
Types of pleural effusion
Transudative pleural effusion
Exudative pleural effusion
Hemothorax
What is transudative pleural effusion caused by
Cardiac failure
Hypoalbuminemia eg nephrotic syndrome. liver disease, protein malnutrition
Etiology of pleural effusion (traumatic)
Blunt trauma
Penetrating trauma (including iatrogenic)
Etiology of pleural effusion (non-traumatic/spontaneous)
Neoplasia (primary or metastatic)
Blood dyscrasias, including complications of anticoagulation
Pulmonary embolism with infarction
Torn pleural adhesions in association with spontaneous pneumothorax
Pathophysio of pleural effusions
Small effusions – no symptoms
Minimum of 300 ml in the pleural cavity to be seen in the x-rays (costophrenic angle)
Large effusions
Interferes with lung expansion with
reduction in vital capacity
Hypoxia and hypercapnia
Clinical features of hemothorax
Acute pleural pain, dyspnea
Small effusions
No findings or shifting dullness on percussion
Large effusions
Decreased chest movements
Shift of mediastinum structures
Dullness on percussion breath sounds
Treatment of hemothorax
If a hemothorax is equal to or greater than the
amount required to obscure the costophrenic
sulcus or is found in association with a pneumothorax based on chest radiograph findings, it should be drained by tube thoracostomy
What is pneumothorax
Collection of air in pleural cavity
When should surgical exploration in cases of traumatic hemothorax be performed
Greater than 1000 mL of blood is evacuated immediately after tube thoracostomy. This is
considered a massive hemothorax.
Bleeding from the chest continues, defined as 150-200 mL/h for 2-4 hours.
Persistent blood transfusion is required to maintain hemodynamic stability
Types of pneumothorax
spontaneous / chest trauma
cause of Spontaneous pneumothorax
Rupture of bulla(e) on surface of lungs
Bronchial asthma, COPD, tuberculosis
why chest trauma results in pneumothorax
Negative pleural pressure will allow air to enter
Clinical features of pneumothorax
Acute pleural pain, dyspnea in large pneumothorax
Decreased chest movements
Shift of mediastinal structures
Hyper-resonance on percussion and absent breath sounds
Tension pneumothorax arises from progressive _____ of a simple ______
Arises from progressive worsening of a simple pneumothorax
Tension pneumothorax is associated with formation of a _______ at point of _____ in the lung
Associated with formation of a one-way valve at point of rupture in the lung
In tension pneumo, air becomes ___ in ______ and builds up which:
Air becomes trapped in pleural cavity and builds up -> Prevents lung from inflating fully
What is tension pneumo?
Tension pneumothorax: The accumulation of
air under pressure in the pleural space.
The air enters the pleural cavity and is trapped there during expiration so the air pressure within the thorax mounts higher than atmospheric pressure, compresses the lung,
may displace the mediastinum and its
structures (including the lung) toward the opposite side, and cause cardiopulmonary impairment (decrease cardiac output)
Tension pneumo causes collapse of ___ and shift of ___ structures
Causes collapse of lung and shift of mediastinal structures
**CVS collapse due to poor VR (venous return)
Complications of pneumothorax
Venous return and cardiac output decrease with
hypotension and tachycardia
Hypoxemia due to alveolar collapse
Reexpansion pulmonary edema
Bronchopleural fistula - Bronchopleural fistula (BPF)
is a sinus tract between the main stem, lobar, or segmental bronchus and the pleural space
Diagnosis of pneumothorax
- Chest radiography
– Requires good quality film
– In ICU, 30% of pneumothoraces are missed due to: - Low-quality film
- Supine position of patient on AP film
- Air hidden behind thoracic or mediastinal structures
Radiographic appearance
Mediastinal shift, diaphragmatic depression, flattened ribs
CT scan - used to confirm size and presence of pneumothorax.
What is reexpansion pulmonary edema?
Occurs following rapid lung reexpansion particularly:
From low lung volumes
Long duration pneumothorax
High pressure gradient across lung
May be related to reperfusion injury
Lung reexpansion should be slow
* First, just waterseal, no suction
* If lung fails to reexpand, then apply suction
Medical mgmt of pneumothorax
- Oxygen
– Should be administered to all patients
– Supplemental O2 speeds absorption of air from pleural space - Observation of stable patients
– Primary: observe 4 hours, if no enlargement: home
– Secondary and iatrogenic: hospitalize and observe carefully,
* If there is any deterioration (SpO2, RR, etc) - drain - Simple aspiration
– Small catheter placed in pleural space
– Connect to three-way stopcock
– Slowly evacuate until no more air can be removed
– This works as many leaks heal between time of leak and its
drainage.
– If 4 L air is removed without resistance, chest tube placement is
required - Chest tubes
– Resolution is mostly determined by lung healing
– Small bore: placed via small incision in second intercostal space
(ICS), midclavicular line or laterally, fifth–seventh ICS
* Connected to underwater seal or Heimlich valve
– Large bore: placed via blunt dissection, usually connected to
“three-bottle” chest drainage system
– Chest tubes are sutured in place - Pleurodesis
– consider with recurrent
pneumothoraces
When is chest tube placement required in pneumothorax?
– If 4 L air is removed (thru simple aspiration) without resistance, chest tube placement is required
What is pulmonary edema?
Life threatening emergency in which excess fluid
accumulates in lungs
Characterized by extreme breathlessness
Due to alteration of capillary forces in the alveolar wall
Causes of pulmonary edema
Increased Venous hydrostatic pressure
LVF (most common cause)
Decreased Plasma osmotic pressure
Hypoalbuminemia
Altered alveolar capillary membrane
permeability
Acute respiratory distress syndrome (ARDS)
Pathophysio of pul edema
Increased pulm capillary pressure
Engorged vessels, lungs less compliant
Increased resistance of small airways (Tachypnoea, wheezing)
If pressure ↑ > 25mmHg (normal 15)
Increased filtration of fluid into interstitial space , causing interstitial edema
Gas exchange worsens
Xray changes –Kerley B lines
Accumulation of fluid disrupts intercellular membranes
Leads to collection of fluid in alveolar spaces
Alveolar edema
Clinical features of pul edema
Anxiety, profuse
perspiration
Acutely breathless
Tachypnea, tachycardia
Wheezing, crepitations
Cough
- Productive of frothy, blood-tinged sputum
- Can be copious
What is PULMONARY EMBOLISM
Blockage and obstruction of a
pulmonary vessel by a blood-borne
substance
Common cause of unexpected death
Often missed as symptoms are often
non-specific
causes of pul embolism
Thrombus (most common)
Air
Fat
Amniotic fluid
Parasites
Septic emboli
Tumor (renal cell Ca with secondaries to ivc)
Risk factors of pul embolism
Virchow’s Triad
1. Venous stasis
Prolonged bed rest
Immobilization
Low CO
Pregnancy
2. Hypercoagulability
Tissue injury after surgery, trauma
Malignancy
3. Vessel wall inflammation
Pathophysio of pul embolism
Normally, microthrombi form and are
removed continuously in venous
system
Pulmonary vessels act as filters (Remove small emboli from reaching arterial system)
Large clots can damage lung/heart
function
> 95% arise from thrombi in deep
veins of LL
Hemodynamic changes
Obstruction causes ↑ in pulmonary P
RV strain if embolus is large or pre-existing heart disease -> Decreased CO
Large embolus occludes pulmonary bld flow -> No CO -> Sudden death
Change in V/Q ratio
Perfusion distal to obstruction ↓ -> Results in compensatory
hyperventilation initially
Eventually, hypoxemia causes ischemic damage to alveolus
Alveolar collapse -> Pulmonary edema -> ↓ surfactant -> Release of inflammatory chemicals
Pulmonary infarction
Occurs in 10% of cases
Clinical features of pul embolism (SMALL emboli)
effort dyspnoea
tiredness
syncope
cardiac arrhythmias
Clinical features of pul embolism (MASSIVE emboli)
Sudden severe central chest pain
Marked tachypnea, dyspnea
Shock
Clinical features of pul embolism (in general)
Classic triad of sudden onset of
Dyspnea, pleuritic pain, hemoptysis
20% of patients
Swollen, tender, warm calf
Auscultation
Inspiratory crackles
Pleural rub
Wheezing
ECG
Sinus tachycardia
S1Q3T3 - Deep S in lead I, Q wave, inverted T in lead III
The percussion of chest of chest on the patient would reveal a dull percussion. What would be your impression if the dull percussion note changes to hyper-resonant percussion?
Tension pneumothorax
Dull percussion: usually due to presence of fluid (hemothorax)
In normal lungs: expected percussion note should be resonant
In simple pneumothorax: Percussion note will also be resonant
In larger pneumothorax (e.g. tension pneumothorax): Percussion note will progress to hyper-resonant
What is the best initial test in the diagnosis of hemothorax?
a. CXR
b. Chest ultrasound
c. CT scan
d. CT angiography
CXR
What is the definitive test in diagnosing hemothorax?
a. Chest CT scan
b. CXR
c. Chest ultrasound
d. MRI
Chest CT scan
What are the causes of spontaneous hemothorax?
a. RTA
b. An accidental knick during a CTVS surgery
c. metastasis to the pleura
d. Pulmonary embolism
Metastasis to the pleura
Which of the following are potential life-threatening complications
that can occur in massive haemothorax if the blood is allowed to retain in the pleural space?
a. Hemopneumothorax and obstructive shock
b. Septic shock and lung atelectasis
c. Cardiogenic shock and cardiac failure
d. Mediastinal spread and septic shock
Septic shock and lung atelectasis
What should you do to avoid damaging the
neurovascular bundle (Intercostal vein,
artery and nerve (in this order)) during
insertion of the chest tube?
a. Avoid the upper border of the rib while inserting the chest tube
b. Avoid the lower border of the rib while inserting the chest tube
c. Local anesthesia will prevent injury to the neurovascular bundle
d. Inserting the tube in the anterior axillary line will avoid any neurovascular damage.
Avoid the lower border of the rib while inserting the chest tube
Which of the following treatment options is suitable if the chest tube drainage shows clear fluid instead of blood like substance and the drainage amount continues to increase?
a. Pleurodesis
b. Thoracotomy
c. Continue with Chest tube drainage
d. CT guided aspiration of pleural fluid
Pleurodesis: a procedure in which pleural space is artificially obliterated. Involves the adhesion of the 2 pleurae.
1500cc
