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. 2019 Apr 23;2019(4):CD013315. doi: 10.1002/14651858.CD013315

Heo 2014.

Methods Design: parallel (2 arms)
Country: Nepal
Multisite: no
International: no
Treatment duration: 30 days
Follow up: unclear
Rate of ascent (m/h): 712 m/h, 214 m/h
Final altitude reached: 4130 m
AMS scale: Lake Louise Score
Participants

  1. 45 subjects with Hb ≤ 15.5 g/dL were willing to participate. 6 men had Hb > 15.5 g/dL and they were excluded. The remaining 39 subjects were enrolled and randomized

  2. Exclusion criteria: history of cardiovascular disease or other serious illness; uncontrolled hypertension ( > 140/90 mmHg); current smokers; known hypersensitivity to mammalian cell‐derived products

  3. Participants randomized to

    1. EPO group: n = 20 (51%)

    2. Control group: n = 19 (49%)

  4. No randomized participants were excluded or lost at follow‐up

  5. Main characteristics of participants

    1. Age (mean ± SD) = 44.5 ± 12.6 years (range, 18 to 65 years)

    2. Number of men: 16 (41%)

    3. Body mass index (mean ± SD): EPO group = 22.3 ± 2.5; control group = 22.9 ± 2.2
Interventions EPO group (Intervention): 10,000 IU epoetin alpha subcutaneous injections once per week for 4 consecutive weeks, starting 5 weeks before departure. The last injection was given 7 days before departure.
Control group (control): unclear
Cointerventions

  1. Aspirin 100 mg/day

  2. All subjects received sildenafil when they arrived at the base camp (4130 m), 2 doses morning and before sleep, and the next day 1 additional dose
Outcomes Outcomes were not pre‐defined as primary or secondary

  1. Lake Louise scores (LLS)

  2. AMS onset

  3. Number of subjects who met immediate descent criteria (according to US Army Research Institute of Environmental Medicine criteria)

  4. Systolic and diastolic blood pressure, and pulse rate

  5. Arterial oxygen saturation (SaO₂)
Notes

  1. Trial registration: NCT01665781

  2. Sponsor: CJ Pharmaceutical (Asan Medical Center Clinical Research Center 2012‐0534)

  3. Role of sponsor: unclear: "provide the erythropoietin and sildenafil" Page 416

  4. A priori sample size estimation: no

  5. Conducted: not stated

  6. Declared conflicts of interest: yes
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Low risk Quote "The randomization sequence was generated by computer at the Asan Medical Center. Block randomization to ensure gender or age equivalence between groups was not performed" Page 417
Allocation concealment (selection bias) Unclear risk Insufficient information to score this item as low or high risk of bias
Blinding of participants and personnel (performance bias) 
 All outcomes High risk Quote “First, our study was not blinded, which may affect the results …” Page 421
Blinding of outcome assessment (detection bias) 
 All outcomes High risk Quote “First, our study was not blinded, which may affect the results …” Page 421
Incomplete outcome data (attrition bias) 
 All outcomes Low risk No participants were lost at follow‐up
Selective reporting (reporting bias) High risk Patient‐important outcomes, such as adverse events, were not reported.
Other bias Low risk No other biases were identified