Pneumothorax

Description

presence of free air in the intrapleural space (between parietal and viseral pleura)
types:

Spontaneous (primary) pneumothorax.

Due to non-traumatic rupture of alveolous, bronchiole, or bleb

No underlying pulmonary pathology present

Often due to rupture of small subpleural cyst or bleb

Occurs primarily in young, healthy patients (ages 15-40yo), with tall and thin body habitus

Secondary spontaneous pneumothorax from underlying lung pathology

COPD, asthma, cystic fibrosis,

infections: necrotizing bacterial pneumonia, TB, fungal pneumonia, PCP

neoplasm

Interstitial lung disease: sarcoid, pulmonary fibrosis, pneumoconioses

Trauma

broken rib, ruptures bronchus, blunt trauma, penetrating wound, etc.

Iatrogenic

central line placement, etc

seen in ~3% of ICU patients

"Tension pneumothorax"

Air continues to enter pleural space through broncoalveolar disruption and becomes trapped via ball-valve mechanism

Intraplural pressure then increases

venous return to right heart decreases, resulting in decreased cardiac output

mediastinum can shift toward uninvolved side, which further interferes with right atrial filling. May note tracheal deviation as well.

V/Q mismatch results in hypoxia

Signs and Symptoms

severity of symptoms is proportional to the size of the pneumothorax

ipselateral pleuritic chest pain, cough, dyspnea, referred pain to shoulder

rapid, shallow breathing

moderate to severe: profound respiratory distress, hypotension, shock, cyanosis

Diagnosis

drop in oxygen saturation may be first indicator

Upright chest X-ray

absence of lung markings distal or peripheral to the visceral pleaural white line

displacement of mediatinum

"Deep sulcus sign"= on a supine chest radiograph is an indication of a pneumothorax. In a supine film, it may be the only indication of a pneumothorax because air collects anteriorly and basally, within the nondependent portions of the pleural space as opposed to the apex (of the lung) when the patient is upright. The costophrenic angle is abnormally deepened when the pleural air collects laterally, producing the deep sulcus sign. (See * on image below)

Chest CT-- very sensitive for small pneumothorax, but has little practical advantage over CXR.

Treatment
1. Cardiac monitoring, pulse ox, oxygen 100% via nonrebreather face mask, IV access
2. Nontraumatic pneumothorax estimated at <15% collapse and no cardiovascular or respiratory compromise can be observed with 100% oxygen support
  - consider simple aspiration if increase in size of pneumothorax (still 155- 30%) is noted during observation. Place aspiration catheter (usually 8 Fr) with 3-way stopcock. Aspirate air until resistance or 3L aspirated. If no pneumothorax is visible on two CXRs taken 4 hours apart, then the catheter can be removed. Repeat CXR 2 hours after catheter removed to see if pneumothorax has recurred. Consider Hemlich valve or suction if simple aspirationis unsuccessful.
3. Suspected tension pneumothorax requires immediate needle thoracostomy or chest tube is indicated in an unstable patient
  - 14 to 18 guage angiocatheter is placed in second intercostal space at the midclavicular line, or at the 4th or 5th intercostal space at the anterior axillary line.
  - Video:
    http://www.youtube.com/watch?v=4cuotNQPRNc#
1. Chest tube

Indications: pneumothorax with >30% collapse or cardiovascular instability

is the definitive therapy after needle thoracostomy

required if pneumothorax of any size in a patient receiving positive pressure ventilation

tube size:

small caliber (7-14 Fr) tube for spontaneous pneumothorax

20-28 Fr for secondary spontaneous pneumothorax

28 Fr when there is detectable pleural fluid or anticipated need for mechanical ventilation

Following insertion, the tube should be connected to a water-seal device

Video:
http://www.youtube.com/watch?v=QM85GdT4ZVY&feature=related

References:

1. Baumann MH, Strange C, Heffner JE, et al. Management of spontaneous pneumothorax. Chest. 2001; 119:590. S193.

2. Sahn SA. Spontaneous pneumothorax. New England Journal of Medicine. 2000; 342:868.

3. Light RW. Pleural Diseases. 4th edition. Lippincott, Williams & Wilkins. 2001.

standard medicine admit orders

1. Chest Pain ( R/O ACS)

1. Admit to LSU medicine, Telemetry Attending Dr: _________________ , resident: _________, intern: _________

2. Dx: Chest Pain – R/O MI Contributing Dx:

3. Condition: [ ] Stable [ ] Fair [ ] Serious [ ] Critical 4. VS: Q 4 hr with pulse ox checks Call MD if: P < 50 or > 110, BP < 90/60 or > 150/90, R > 25, chest pain unrelieved with 3 NTG or CP with telemetry changes.

4. Activity: Bed rest with bedside commode

5. Nursing: strict I's/O's Q shift; O2 via NC to keep sats > 93, weight on arrival and each am; STAT EKG for significant chest pain or arrhythmia.

6. Diet: AHA step I cardiac twink diet without caffeine.

7. IV: Hep-Lock

8. Meds: ASA 325 mg PO now (if not given yet in ER) and Q am. NTG 0.4mg SL prn CP, may repeat Q 5 min until pain free or max 3 Tylenol 500 mg PO Q 4 hr prn HA or pain. Ambien 5 mg PO QHS prn insomnia. Nexium 40mg PO qD

9. Other twink Meds to consider now: statin, antihypertensives, Lovenox (1mg/kg BID)

10. Labs:1. Cardiac enzymes (CK, CK-MB, troponin) with EKGs on admission (if not done in ER) and 6 hr later for total of 3 (put exact time the blood draws should occur). 2. CBC, BMP, MG, phos, qAM 3. TSH with next blood draw 4. fasting Lipid profile in am. 5. CXR (portable) if not done in ER.

11. potential further cardiac tests in AM:

2. Community-Acquired Pneumonia

3. HF exacerbation

4. Asthma/ COPD exacerbation

5. GI bleed

6. DKA

1. Fluids – Correct fluid deficit rapidly by giving 1-2 Liters bolus and high IVF rate after that. Starte with NS then change to 1/2NS as glucose falls. Finally switch to D51/2NS when glucose falls <200.

2. Insulin – 0.1-0.4 units/kg bolus IV regular insulin followed by 0.1-0.2 units/kg/hr. Aim for a 75-100 drip in serum glucose per hour. Continue insulin drip twink acidosis has resolved, AG closes and glucose<200.

3. Electrolytes – Expect them to become abnormal. Stay on top of electrolytes (K & Phos especially) with frequent BMP’s q 2-4 hours initially. Expect K to fall with IVF and insulin. This will likely have to be repleted. Sodium needs to be corrected for level of glucose.

Corrected Na = 0.016(measured glucose-100) + measured Na.

4. Acidosis – due to ketones. Expect that this will gradually resolve with above measures. If there is a persistent serum ketosis as measured by the AG, suspect an ongoing insulin deficit.

7. etc.