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We would wholeheartedly agree with Simon Leigh-Smith's comments that
overall there will be hyperexpansion and a hypomobile chest on the
affected side in a tension pneumothorax. The hyperexpansion will mean
there will be ‘reduced chest expansion’ with each inspiratory effort but
perhaps the word ‘expansion’ should have been replaced with ‘movement’ to
clarify this point.
This paper stated prevalence of Tension Pneumothorax which is
misleading and up to 20 times higher than that which might be seen by the
standard pre-hospital care practitioner. Further analysis of the two
references used for this statement is given and it can be seen that their
results should not be extrapolated to the general pre-hospital environment
Coats described tension pneumothorax in up to 5.4% of patients, 64%
of whom were ventilated. They were also a major trauma sub-group.
McPherson looked retrospectively at US soldier fatalities in Vietnam
- when there was no pre-hospital chest decompression. His abstract and
discussion however, mis-represent the figures stated in his results and
the study has methodological floors. Accepting these floors though, he
observed that fatal tension pneumothorax may have occurred in up to:
0.3% of American casualties (26/7801)
3.9% of casualties who died and had signs of a chest wound (26/663)
Despite its floors McPherson’s paper may be more applicable to the
average pre-hospital clinician as it looks purely at awake patients.
However, the external validity of both these papers (which look at
high risk groups) to pre-hospital clinicians seeing a predominance of
blunt trauma, awake patients should be questioned.
The inference that should be taken away by the reader is that "fatal
tension pneumothorax is very unlikely to occur in more than 0.3% of awake
patients encountered in pre-hospital care" Even this is probably too high,
but may go some way to stemming the tide of iatrogenic, needle induced
1. McPherson JJ, Feigin DS, Bellamy RF. Prevalence of tension pneumothorax in fatally wounded combat casualties. J Trauma 2006;60:573–8.[Medline]
2. Coats TJ, Wilson AW, Xeropotamous N. Pre-hospital management of patients with severe thoracic injury. Injury 1995;2:581–5.[CrossRef]
Table 1 states decreased ipsilateral expansion found in tension
pneumothorax. This is incorrect. A HYPER-expanded (and hypo-mobile)
ipsilateral hemi-thorax is almost pathognomonic of this condition.