Latar Belakang: Walaupun pesawat terbang telah dilengkapi dengan perangkat oksigen dan kabin bertekanan, kemungkinan hipoksia masih ada apabila terjadi kegagalan dari kedua sistem tersebut. Pengetahuan mengenai rentang waktu terjadinya hipoksia awal dan faktor-faktor kardiorespirasi yang berkorelasi dengan rentang waktu hipoksia awal perlu diketahui dan diteliti.Metodologi: Studi eksperimental dilakukan pada 130 calon siswa Sekolah Penerbang TNI AU berusia 21-26 tahun; pada keadaan permukaan bumi diukur kadar hemoglobin, saturasi oksigen, fungsi faali kardiorespirasi dan kadar gula darah. Dalam ruang udara bertekanan rendah subyek dipajankan pada kondisi hipobarik dengan ketinggian setara 18.000 kaki. Diukur rentang waktu mulai saat pemajanan sampai terjadi saturasi oksigen 85 % dengan alat pulse oksimeter.Hasil: Pada penelitian ini ditemukan rerata waktu terjadinya hipoksia awal 199,65 detik ; (95 % CI:192,64 - 206,66 detik). Faktor-faktor yang berkorelasi positif secara bermakna adalah kadar hemoglobin (r = 0,3396 ; p = 0,000) dan kadar gula darah (r = 0,4108 p = 0,000). Sedangkan frekuensi denyut nadi mempunyai korelasi negatif kuat (r = -0,4324 ; p=0,000). Model regresi yang sesuai untuk prediksi rentang waktu hipoksia awal terdiri dari faktor-faktor kadar hemoglobin frekuensi denyut nadi dan kadar gula darah.Kesimpulan: Dengan mengetahui kadar hemoglobin, frekuensi denyut nadi dan kadar gula darah dapat diprediksi rentang waktu terjadinya hipoksia awal.

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Elapsed Time To Early Hypoxia At Simulated Altitude 18.000 Feet In Hypobaric Chamber Indicated By 85% Oxyhaemoglobin Saturation And Its Influencing Factors Among Indonesian Air Force Flight Cadets.Background. Although aeroplanes are equipped with oxygen equipment and cabin pressurization, possibilities of hypoxia incidence still exists if there are system's failure. Information on elapsed time to early hypoxia should be available, and its correlation with cardiorespiratory factors should be investigated.

Methods. An experimental study on 130 Indonesian Air Force Flight Cadets age 21-26 years was conducted. Haemoglobin, oxyhaemoglobin saturation, cardiorespiratory function and blood sugar at ground level was measured In hypobaric chamber subjects were exposed to simulated altitude 18.000 feet environment. Elapsed time between the beginning of hypobaric exposure to early sign of hypoxia indicated by 85% oxyhaemoglobin satin-lion was measured.

Result. Average elapsed time to early hypoxia was 199, 65 seconds; (95 % CI:192,64 - 206,66 seconds). Significant positive correlation was found to haemoglobin (r = 0,3396 ; p = 0,000) and blood sugar levels (r = 0,4108 ; p = 0,000). Pulse rate showed negative correlation with elapsed time to early hypoxia (r = -0,4324 ; p = 0,000). The suitable regression model for estimating elapsed time to early hypoxia include haemoglobin,pulse rate, and blood sugar levels.

Conclusion. Predicted elapsed time to early hypoxia could be estimated by using haemoglobin, pulse rate, and blood sugar levels.