Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.
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Question: Abstract: Pulmonary edema due to upper airway obstruction can be observed in a variety of clinical situations. The predominant mechanism is increased negative intrathoracic pressure, although hypoxia and cardiac and neurologic factors may contribute. Laryngospasm associated with intubation and general anesthesia is a common cause of pulmonary edema in children. However, only seven cases of pulmonary edema presumably due to laryngospasm have been reported in adolescents and adults. Five of the seven had other risk factors for upper airway obstruction, and in four, the diagnosis of "laryngospasm" could be explained by other factors. Patients with underlying risk factors for upper airway obstruction, such as a forme fruste of sleep apnea or nasopharyngeal abnormalities, appear to be at increased risk for the development of pulmonary edema in the setting of intubation and anesthesia. This form of pulmonary edema usually resolves rapidly without the need for aggressive therapy or invasive monitoring.

Answer: Airway Obstruction

Question: Abstract: The pharmacokinetic characteristics of testosterone propionate were studied in normal men after a single im dose of 25 mg testosterone propionate-19,19,19-d3. Plasma levels of testosterone propionate-19,19,19-d3, its active metabolite testosterone-19,19,19-d3, and endogenous testosterone were measured by gas chromatography-mass spectrometry. Testosterone propionate-19,19,19-d3 was gradually transferred from the im injection site to the systemic circulation. The plasma levels of testosterone propionate-19,19,19-d3 were maintained at 2-4 ng/ml between 3 and 36 h after administration. Plasma testosterone-19,19,19-d3 levels were maintained above the physiological testosterone level for 48 h, while plasma levels of endogenous testosterone changed little.

Answer: Adult

Question: Abstract: Concentrations of catecholamines in vitreous fluid and urine in guinea pigs dying of cold and the effects of freezing and autolysis on these parameters were studied. The analysis was performed by high performance liquid chromatography with electrochemical detection. Noradrenaline (NA) concentration in vitreous fluid was more than 20 times higher in the cold exposed animals than in controls (44.2 +/- 9.2 versus 2.0 +/- 1.0 ng/mL). Autolysis alone caused an increase to 33.5 +/- 7.7 ng/mL, and freezing alone to 13.4 +/- 5.3 ng/mL. The highest values were in the group with exposure, freezing, and autolysis. Adrenaline (A) concentration in the vitreous fluid increased fourfold (3.9 +/- 1.5 versus 0.7 +/- 0.5 ng/mL) in cold exposure and twofold as a result of autolysis. Dopamine (DA) concentration in vitreous fluid was elevated only in the group with exposure, freezing, and autolysis. The increase of NA concentration in urine was fivefold during the whole exposure (from 19.4 +/- 6.9 to 109 +/- 57.3 ng/mL), but A was increased by twentyfold (from 10 +/- 5.1 to 213.2 +/- 168.7 ng/mL), whereas DA concentration did not change. The increase of average excretion of NA to urine was eightfold during the first 6 h of exposure, and that of A tenfold. According to the present results, elevated concentrations of catecholamines in the vitreous fluid and urine can be used as a diagnostic aid for hypothermia death. Concerning the values of noradrenaline in the vitreous, the increase as a result of autolysis must be taken in account when interpreting the results.

Answer:
Animal