Chest drains in traumatic occult pneumothorax

Chest drains in traumatic occult pneumothorax

Report by Rachel Jenner, Specialist Registrar

Search checked by Ayan Sen, Clinical Fellow

Stepping Hill Hospital, Stockport

A short cut review was carried out to establish whether tube thoracostomy was indicated in trauma patients who have an occult pneumothorax discovered on CT scanning. 279 papers were found using the reported searches, of which six presented the best evidence to answer the clinical question. The author, date, and country of publication, patient group studied, study type, relevant outcomes, results, and study weaknesses of these best papers are tabulated. It is concluded that minimal occult pneumothoraces can be observed but that there is no evidence to show that this is a safe approach if the pneumothorax is larger.

Clinical scenario

A 30 year old man is brought into the Emergency Department after a road traffic accident. A chest x‐ray taken as part of the ATLS trauma series is normal and he has no clinical signs of chest injury. He has an abdominal CT for investigation of blunt abdominal trauma. This reveals an occult pneumothorax. You wonder whether you should insert a chest drain.

Three‐part question

In [a patient who has sustained blunt trauma who is found to have an occult pneumothorax on CT scan] is [tube thoracostomy better than observation] at reducing [morbidity and mortality]?

Search strategy

Medline 1966 to October Week 4 2005 using the OVID interface. [exp pneumothorax/ or pneumothorax.mp] AND ([exp “wounds and injuries”/OR trauma.mp] OR chest drain.mp OR exp chest tubes/ OR exp thoracostomy]) AND ([exp Tomography, X‐ray computed OR CT.mp] OR occult.mp) LIMIT to human AND English

Embase 1980 to 2005 week 47. [exp pneumothorax/or pneumothorax.mp.] AND [exp injury/or exp wound/ or trauma.mp. or exp thorax drainage/or chest drain.mp. or thoracostomy.mp.] AND [exp computer assisted tomography/ or CT.mp. or exp occult blood/] Limit to human and English, Age groups ‐ All adult 18–64 years and 64 years >

The Cochrane Library Issue 4 2005. Chest drains [MeSH} AND pneumothorax [MeSH] 23 hits

Outcome

Altogether 279 papers were found of which 273 were irrelevant or of insufficient quality for inclusion

Table 1.

Author, country, date	Patient group	Study type	Outcomes	Key results	Study weaknesses
Garramone et al, 1991,USA	26 trauma patients aged 14–65 with occult pneumothorax (OPTX) on abdominal CT. Classified as <5×80 mm or > = 5×80 mm	Retrospective chart review	Complications of OPTX, respiratory or haemodynamic compromise	No patient had haemodynamic or respiratory complications.	Retrospective Small numbers
				Of 18 with small OPTX: 2 had chest drains for increasing subcutaneous emphysema, 1 for increasing PTX.
				Of 13 patients with larger OPTX 4 had prophylactic chest drains, 3 for increasing subcutaneous emphysema 2 for increasing effusion
Collins et al, 1992, USA	23 patients aged 18–82 with occult pneumothorax	Retrospective chart review	Length of hospital stay (mean)	13.4 days vs 8.8 days	Small study Retrospective
			Length if ICU stay	6.3 days vs 3.3 days	Not randomised
	Immediate chest tube (n = 12) vs observation (n = 11)		Complications	1 pt in immediate chest tube group: had laceration of intercostal artery.
				2 observed pts had eventual chest tubes for enlarging pneumothorax or haemothorax
Enderson et al 1993 USA	40 adult trauma patients	PRCT	Length of hospital stay	12.9 vs 17.6 days	Small study
	Randomized to immediate chest tube (n = 19) or observation (n = 21)		Length of ICU stay	2.8 vs 3.2 days
			Complications	Immediate chest tube: 1 pneumonia, 8 atelectasis.
				Observation group 3 tension pneumothorax, 5 progression pneumothorax, 1 pneumonia, 1 empyema, 3 atelectasis
Wolfman et al 1998, USA	44 pts aged 17 months –70 yrs with occult pneumothorax, classified according to size into miniscule, anterior or anterolateral. Chest tube inserted dependent on size and at trauma surgeons discretion	Prospective non‐randomized	Complications	15/16 with miniscule observed, 2 had delayed chest drain for pneumothorax progression. 12/20 anterior observed 1 developed tension pneumothorax. 8 with anterolateral had immediate chest drain, no complications	Small numbers
					Both adults and children
Brasel et al 1999, USA	39 adult patients with occult pneumothorax randomised to chest tube (n = 18) or observation (n = 21)	PRCT	Respiratory distress	1 pt with chest tube was intubated for stridor. 3 observed pts had resp distress with pneumothorax progression	Only 39 of 86 eligible pts recruited
Holmes et al 2000, USA	11 children <16yrs with occult pneumothorax presenting to level 1 trauma centre. 1 had chest tube, 10 observed	Prospective observational cohort study	Complications	No haemodynamic or respiratory complications	Small numbers paediatric population

Comments

All the papers report small numbers. There are conflicting results. Some classify occult pneumothoraces into size but different techniques are used

Clinical bottom line

It appears reasonable to treat minimal occult pneumothoraces with observation, there is no evidence whether it is safe to extend this to larger occult pneumothoraces