Volatile organic compounds as diagnostic breath markers for pulmonary oxygen toxicity
A set of volatile organic compounds is provided, comprising Benzene, 2,3,4-trimethyl-Pentane, 1,4-dimethyl-, trans-Cyclohexane, 2,2,4-trimethyl-Hexane, 1,7,7-trimethyl-Tricyclo[2.2.1.0(2,6)]heptane, and 4-ethyl-3-Octene for breath analysis. Methods of identifying these VOCs and use thereof in diagnosing, monitoring the onset of pulmonary toxicity are also disclosed.
1. A method of detecting onset of pulmonary oxygen toxicity in a subject comprising:
a) collecting a breath sample from a subject who has been exposed to an oxygen enriched atmosphere;
b) detecting in said breath sample the level of a set of volatile organic compounds selected from the group consisting of benzene; 2,3,4-trimethyl pentane; 1,4-dimethyl-trans cyclohexane; 2,2,4-trimethyl-hexane; 1,7,7-trimethyl-tricyclo heptane; and 4-ethyl-3-octene; and
c) predicting onset of pulmonary oxygen toxicity in said subject.
2. The method according to claim 1 , wherein presence of all volatile organic compounds of (b) in said breath sample indicates the onset of pulmonary oxygen toxicity in said subject.
3. The method according to claim 1 , further comprising:
a) collecting a control breath sample from said subject that is collected before exposing said subject to an oxygen enriched atmosphere;
b) detecting the level of a set of volatile organic compounds selected from the group consisting of benzene; 2,3,4-trimethyl pentane; 1,4-dimethyl-trans cyclohexane; 2,2,4-trimethyl-hexane; 1,7,7-trimethyl-tricyclo heptane; and 4-ethyl-3-octene in said before and after exposure breath samples;
wherein a significant change in the levels of said volatile organic compounds in the breath samples before and after said exposure to oxygen enriched atmosphere is indicative of onset of pulmonary oxygen toxicity.
4. The method according to claim 3 , wherein the changes in the levels of said volatile organic compounds in the samples collected after said exposure to oxygen enriched atmosphere form a pattern, which is significantly different from a pattern of said volatile organic compounds in the control breath sample, and is indicative of onset of PO 2 T.
5. The method according to claim 1 , wherein step c) further comprising
a) calculating a breath score based on the level of said volatile organic compounds from said breath sample;
b) predicting a risk of pulmonary injury to said subject if the breath score is greater than −3.5.
6. The method according to claim 5 , wherein the breath score between 0.707 and 0.72 is indicative of the onset of pulmonary oxygen toxicity.
7. The method according to claim 1 , wherein the level of said volatile organic compound is measured by Gas-Chromatography (GC), GC-lined Mass-Spectrometry (GC-MS), Proton Transfer Reaction Mass-Spectrometry (PTR-MS), Electronic nose device, or Quartz Crystal Microbalance (QCM).
8. The method according to claim 7 , wherein the level of said volatile organic compound from said breath sample is measured by Gas-Chromatography-Mass Spectrometry (GC-MS).
9. The method according to claim 1 , wherein the subject is a mammal.
10. The method according to claim 9 , wherein the subject is a human.
11. A method for preventing or reducing pulmonary oxygen toxicity, comprising the steps of
a) collecting a breath sample from a subject at risk of developing pulmonary oxygen toxicity;
b) measuring the level of organic volatile compounds selected from the group consisting of benzene; 2,3,4-trimethyl pentane; 1,4-dimethyl-trans cyclohexane; 2,2,4-trimethyl-hexane; 1,7,7-trimethyl-tricyclo heptane; 4-ethyl-3-octene;
c) detecting onset of pulmonary oxygen toxicity; and
d) reducing said subject's exposure to oxygen enriched atmosphere if onset of pulmonary oxygen toxicity is detected in step c).
12. The method of method 11, further comprising treating said subject for pulmonary oxygen toxicity.
13. A method of identifying a set of volatile organic compounds indicative of pulmonary toxicity comprising the steps of:
a) collecting breath samples from subjects before and after exposing said subjects to an oxygen enriched atmosphere;
b) determining the levels of volatile organic compounds in said breath samples;
c) comparing the levels of volatile organic compounds in breath samples taken after said exposure to levels of volatile organic compounds in breath sample taken before said exposure of the same subject;
d) identifying a set of volatile organic compounds that are significantly different in breath samples collected after said exposure compared to breath samples of the same subjects collected before said exposure;
e) producing a diagnostic algorithm based on profile of said set of volatile organic compounds that is indicative of onset of pulmonary toxicity.
14. The method according to claim 13 , wherein a pattern is analyzed with a pattern recognition analyzer.
15. The method according to claim 14 , wherein the pattern recognition analyzer comprises at least one algorithm selected from the group consisting of principal component analysis (PCA), artificial neural network algorithms, multi-layer perception (MLP), generalized regression neural network (GRNN), fuzzy inference systems (FIS), self-organizing map (SOM), radial bias function (RBF), genetic algorithms (GAS), neuro-fuzzy systems (NFS), adaptive resonance theory (ART), partial least squares (PLS), multiple linear regression (MLR), principal component regression (PCR), discriminant function analysis (DFA), linear discriminant analysis (LDA), cluster analysis, and nearest neighbor.