PMID- 23632222
OWN - NLM
STAT- MEDLINE
DCOM- 20140224
LR  - 20220408
IS  - 1532-6497 (Electronic)
IS  - 1067-991X (Linking)
VI  - 32
IP  - 3
DP  - 2013 May-Jun
TI  - Pneumothorax volume expansion in helicopter emergency medical services transport.
PG  - 138-43
LID - S1067-991X(12)00328-8 [pii]
LID - 10.1016/j.amj.2012.10.014 [doi]
AB  - OBJECTIVE: In accordance with Boyle's law (as barometric pressure decreases, gas 
      volume increases), thoracostomy is often recommended for patients with 
      pneumothoraces before helicopter EMS (HEMS) transport. We sought to characterize 
      altitude-related volume changes in a pneumothorax model, aiming to improve 
      clinical decisions for preflight thoracostomy in HEMS patients. METHODS: This 
      prospective study used 3 devices to measure air expansion at HEMS altitudes. The 
      main device was an artificial pneumothorax model that mimicked a human pulmonary 
      system with a 40 mL pneumothorax. In addition, volume changes were calculated in 
      2 spherical balloons (6 L and 25 L) by measuring equatorial circumferences. 
      Measurements were recorded at 500-foot altitude increments from 1000 to 5000 feet 
      above ground level. RESULTS: The 3 models exhibited volume increases of 
      12.7%-16.2% at 5000 feet compared to ground level. Univariate linear regression 
      yielded similar increases, 1.27%-1.52%, in volume per 500-foot altitude increase 
      for all 3 models. Bivariate indexed linear regression identified no association 
      between volume increase and assessment model (P values .19 and .29). Locally 
      weighted scatterplot smoothing (lowess) plots indicated linearity of the 
      altitude-volume relationship. CONCLUSION: This study demonstrated predictable 
      pneumothorax volume changes at typical HEMS altitudes. Increased understanding of 
      altitude-related volume changes will aid decision making before transport.
CI  - Copyright (c) 2013 Air Medical Journal Associates. Published by Elsevier Inc. All 
      rights reserved.
FAU - Knotts, Derek
AU  - Knotts D
AD  - Department of Emergency Medicine, University of Oklahoma School of Community 
      Medicine and Hillcrest Medical Center, Tulsa, OK 74104, USA.
FAU - Arthur, Annette O
AU  - Arthur AO
FAU - Holder, Peyton
AU  - Holder P
FAU - Herrington, Tim
AU  - Herrington T
FAU - Thomas, Stephen H
AU  - Thomas SH
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Air Med J
JT  - Air medical journal
JID - 9312325
MH  - *Air Ambulances
MH  - Altitude
MH  - *Atmospheric Pressure
MH  - Humans
MH  - *Pneumothorax/pathology/therapy
MH  - Prospective Studies
EDAT- 2013/05/02 06:00
MHDA- 2014/02/25 06:00
CRDT- 2013/05/02 06:00
PHST- 2012/07/31 00:00 [received]
PHST- 2012/10/20 00:00 [accepted]
PHST- 2013/05/02 06:00 [entrez]
PHST- 2013/05/02 06:00 [pubmed]
PHST- 2014/02/25 06:00 [medline]
AID - S1067-991X(12)00328-8 [pii]
AID - 10.1016/j.amj.2012.10.014 [doi]
PST - ppublish
SO  - Air Med J. 2013 May-Jun;32(3):138-43. doi: 10.1016/j.amj.2012.10.014.