The effects of altitude and two decongestant-antihistamine preparations on physiological functions and performance.

PDFTech ReportFAA-AM-78-19DOT/FAA/AM-78/19Air pilotsDrug effectsAltitudePhysiological aspectsPerformanceHeart rateTemperatureBlood pressureUrineFatigue (Physiological condition)AttentionExperimentsHuman subject testingUnited StatesCivil Aerospace Medical InstituteHiggins, E.A.Chiles, W.D.McKenzie, J.M.Jennings, A.E.Funkhouser, G.E.Mullen, S.R.Civil Aeromedical InstituteUnited States. Office of Aviation MedicineNTL-AVIATION-AVIATIONNTL-AVIATION-Aviation Human FactorsNTL-AVIATION-Aviation Safety/AirworthinessNTL-SAFETY AND SECURITY-Aviation Safety/AirworthinessNTL-SAFETY AND SECURITY-Human FactorsUS Transportation CollectionFourteen men were studied to determine the combined effects of two altitudes (ground level (1,274 ft) and 12,500 ft), and three preparations (lactose placebo, Compound A (Actifed - Registered Trade Name), and Compound B (Dristan - Registered Trade Name). Physiological data show that A was a stimulant and B a depressant. Subjects reported least subjective attentiveness with A and greatest with lactose. Significant time effects were evident in subjective ratings (increasing fatigue and decreasing energy interest, and attentiveness). The Multiple Task Performance Battery (MTPB) showed no effects of altitude, drugs, or time on overall performance; however, performance declined from the first to the second hour in several tasks, while problem solving improved.The data are compatible with reported decreasing interest and attentiveness; subjects enjoyed the problem-solving tasks and may have given those tasks preference as their levels of interest declined. Though performance on the MTPB, with the drug doses evaluated, did not produce any changes in the overall composite scores earned by these healthy subjects, the results from physiological parameters and some subjective evaluation indicate that time after ingestion and type of compound ingested are important. Declines in energy and attentiveness 2 1/2 h after ingestion could result in neglect of important although routine tasks. Hypoxia might enhance this effect and consequences might be worse in subjects whose medical conditions require these drugs