Pulmonary Board Review: Pneumothorax

PULMONARY BOARD REVIEW: PNEUMOTHORAX

Management of Spontaneous PTX: An ACCP Delphi Consensus Statement. Chest 2001; 119:590-602.

1. CLASSIFICATION:

a. Spontaneous:

i. Primary

ii. Secondary: COPD/Bullous Empysema, AIDS, Sarcoidosis, CVD, EG, Asthma, IPF, LAM, Malignancy, Catanemial …

b. Traumatic: blunt, penetrating, iatrogenic

2. PRIMARY SPONTANEOUS PTX:

a. rupture of small apical subpleural blebs

b. apical blebs? : higher transpulmonary pressures at apices resulting in overdistension of alveoli, or apices represent areas of relative ischemia in asthenic individuals, or rapid atmospheric pressure changes

c. CXR: usual diagnosis, may need expir and inspir films if small

3. DEFINITIONS:

a. PTX size: distance form lung apex to thoracic cupola

i. Small: <3 cm

ii. Large: >3 cm

b. Stable: RR <24, HR >60 or <120, normal BP, SaO2>90%, speak in full sentences

c. Small size CT = <14F

d. Moderate size CT = 16-22F

4. TREATMENT OF PRIMARY SPONTANEOUS PTX:

a. Small and Stable: monitor 3-6 hours à f/u CXR before discharge and then repeat over next 12 to 48 hours

i. 100% O2 to enhance absorption to increase the N2 gradient b/w alv and pleural air

ii. normally air is reabsorbed from pleural space at rate of 1.25%/24° (= 2 wks for 20%)

iii. if not resorbed in 2 wks need definitive management b/c at risk for developing trapped lung b/c of fibrous peel being laid down on visceral pleura

b. Large and Stable:

i. CT (<14 or 16-22F) and Hospitalize OR Heimlich valve (~8-12F) and Discharge

1. no further air leak à stop sxn à repeat CXR in 5-12 hours à D/C CT if no recurrence

2. persistent air leak à monitor for 3-5 days à thoracoscopic correction if air leak continues

c. Large and Unstable: CT (<14 or 16-22F) and hospitalize à as above

d. PTX recurrence prevention: persistent air leak, second PTX, scuba diving, flying

i. Thoracoscopy preferred intervention – success rate = 95-100%

1. intra-op bullectomy if bullae visualized

2. intra-op pleurodesis with pleural abrasion vs. talc?

ii. Sclerosing Agent if not surgical candidate or decline surgery – success rate = 78-91%

e. Chest CT Scan:

i. not recommended for first time PTX

ii. unclear for recurrent PTX, persistent air leak, planned surgical intervention

5. TREATMENT OF SECONDARY SPONTANEOUS PTX:

a. Small and Stable: hospitalize AND observe OR place CT (<14 or 16-22F)

i. No further air leak à stop sxn à repeat CXR in 13-23 hours à D/C CT if no recurrence

ii. Persistent air leak à monitor for 4-7 days à thoracoscopic correction if air leak continues

b. Large and Stable: hospitalize and CT (<14 or 16-22F) à as above

c. Large and Unstable: hospitalize and CT (24-28F) à as above

d. PTX recurrence prevention: intervention warranted after first PTX

i. Surgery (bullectomy and pleural symphysis) >> sclerosing agent

ii. may use sclerosing agent by CT alone if contraindication to surgery, management preference, or poor prognosis) à Doxy and Talc >> Bleo

e. Chest CT Scan: no consensus, may be useful for PTX recurrence, persistent air leak, and potential surgical management

6. PLEURODESIS:

a. Doxyycline:

i. mechanism by low pH of solution à pleuritis à adhesions

ii. better results when combined with thoracoscopy

iii. 500mg in 100cc NS and 20cc of 1% lidocaine into pleural space à clamp CT for 8° à change positions à unclamp and let to sxn for 48° or until drainage <150cc/24°

b. Talc:

i. finely powdered Mg silicate – 50 grams

ii. effective pleural irritant

iii. SE = fever, pain, fibrothorax, restricted PFTs, talc embolism, Mesothelioma (secondary to contaminants particularly asbestos)

iv. 96 pts with first PTX: recurrence in 5 yrs: aspir=36%, tetra=13%, talc=8%

7. OPERATIVE INDICATIONS: second episode, persistent air leak, unexpanded “trapped lung”, history of contra-lateral PTX, bilateral PTX, Occupational risk: diver, pilot, live in remote area, large bulla, tension PTX, large undrained hemothorax

8. RISK OF RECURRENCE:

a. simple aspiration or CT = 25-50% in 2 yrs

b. after second episode = 50-75%

c. 2030 pts: overall recurrence = 26% and surgery = 16%

9. SPECIAL SETTINGS:

a. AIDS: recurrent PCP

b. Cystic Fibrosis: caution against pleurodesis as may make transplant more difficult

c. Catanemial: within 48-72° of menses

i. air tracking from open cervix into peritoneal cavity thru diaphragm into pleura?

ii. deposits of thoracic implants of endometrium that break down during menses that allow escape of air?

iii. elevated PgF2 causing bronchoconstriction, hyperexpansion, and distal alveolar rupture?

10. COMPLICATIONS:

a. Tension PTX:

b. Reexpansion Pulmonary Edema:

i. via increase in capillary permeability

ii. risks include rapidity of expansion, chronicity of collapse, loss of surfactant, pulm artery pressure changes

c. Persistent Air Leak:

d. Hemothorax: <5%

i. tearing of pleura resulting in hemorrhage

ii. most will tamponade the bleeding point when reexpanded

iii. if continues may need exploration

e. Pneumomediastinum: <1%

i. often seen after activity with pleuritic chest pain and subcutaneous air in neck and chest

ii. hammans crunch = apex of the heart

iii. must R/O perforated esophagus or injury to major airway

iv. usually innocuous

f. Barotrauma:

i. on positive pressure vent and underlying disease

ii. may see interstitial, subcutaneous emphysema, pneumomediastinum, pneumopericardium, pneumoperitoneum – may be harbingers of future PTX