Table 2

Results of 20 trials investigating treatment with hyperbaric oxygen in hypoxic-ischaemic encephalopathy

StudyTotal effectiveness rate (measurement index)Mean (SD) days to recoveryLength of follow-up; losses to follow-upLong term neurological sequelaeMortalityAdverse events
Chen 200017NASeizures controlled, consciousness, and muscle tone. 2-5 fewer days in I than C12-24 months; noneI: 8.1% (3/37), C: 19.4% (7/36) (numbers in text do not add up)I: 5.4% (2/37), C: 5.5% (2/36)NA
Ding 200318I did significantly better than C; P<0.005 (clinical symptoms disappeared in 10 days)NA>10 days; NANANANone
He 200019I: 94% (30/32), C: 67% (20/30); P<0.01 (clinical symptoms disappeared in 10 days)Days in hospital. I: 12.5 (2.8), C: 15.5 (3.1)NA; noneNAI: 0% (0/32), C: 6.7% (2/30)None
Li 200420I: 90% (18/20), C: 60% (12/20); P<0.05 (clinical symptoms—cerebral oedema by ultrasound disappeared in 5 days)NA3 years; probably noneI: 10.0% (2/20), C: 20.0% (4/20)NANone
Lin 200021I: 97% (29/30), C: 73% (22/30); P<0.05 (clinical conditions improved in 1 week)NA5 months to 2 years; none for total effectiveness rate, 7 for neurological sequelaeI: 3.3% (1/30), C: 23.3% (7/30)NANA
Liu 200322*I: 90% (90/100), C: 67% (66/98); P<0.01 (clinical symptoms disappeared in 10 days)NA6-14 months; 34I: 20.4% (18/100), C: 44.7% (34/98)I: 4.0% (4/100), C: 20.4% (20/98); P<0.05NA
Lu 200123NASymptoms. I: 4.3 (2.3), C: 5.8 (2.0); P<0.001NA; noneNAI: 0% (0/29), C: 4.2% (1/24)None
Lu 200324I: 92% (34/37), C: 74% (25/34); P<0.01 (clinical symptoms—cerebral oedema—disappeared in 10 days; how cerebral oedema was detected not given)Muscle tone. Grade II: I: 6.94 (2.06), C: 7.48 (2.20); P<0.05; grade III: I: 11.17 (2.57), C: 12.44 (3.32); P<0.01. Reflexes. Grade II: I: 4.54 (1.53), C: 5.47 (1.96); P<0.01; grade III: I: 9.29 (2.57), C: 10.33 (2.74); P<0.01. Consciousness. Grade II: I: 3.19 (1.04), C: 3.88 (1.49); P<0.05; grade III: I: 5.14 (1.81), C 6.44 (1.87); P<0.01NA; noneI: 16.2% (6/37), C: 26.5% (9/34); P<0.01NANone
Lu 199925*I: 97% (31/32), C: 70% (21/30); P<0.05 (clinical symptoms disappeared in 10 days)NA>10 days; noneNANANone
Si 199926I: 93% (53/57), C: 76% (37/49); P<0.01 (clinical symptoms and convulsions disappeared in 10 days)Days in hospital. I: 12.8, C: 17.63 months to 4 years; none for total effectiveness, not clear for long term sequelaeI: 7.0% (4/57), C: 12.2% (6/49)I: 5.3% (3/57), C: 16.3% (8/49)NA
Song 200027*I: 90% (46/51), C: 66% (33/50); P<0.01 (clinical symptoms disappeared in 14 days)NA6-14 months; I: 3, C: 11I: 18.8% (9/50), C: 43.6% (17/50); P<0.05I: 5.9% (3/51), C: 22.0% (11/50)NA
Sun 200032I: 93% (39/42), C: 58% (33/40); (cured, improved, alive; time to outcomes not given)NANot clear; noneNAI: 7.1% (3/42), C: 17.5% (7/40)NA
Sun 199833I: 100%, C: 76% (numbers not given); P<0.01 (measurement index not mentioned)NANA; NANANANone
Wang 200234NASeizure controlled; recovery of muscle tone, reflexes, and consciousness. 4-6 days fewer in I than CNA; noneNANANA
Wang 199935I: 97% (22/23), C: 68% (15/22); P<0.05 (clinical symptoms disappeared in 10 days)NA>10 days; noneNANANA
Wang 200136I: 100% (80/80), C: 80% (64/80); P<0.05 (cerebral oedema—by computed tomography—disappeared in 10 days)Symptoms. At least 3 days fewer in I than C10 days; noneNANANA
Wang 200137I: 90% (76/84), C: 76% (61/80); P<0.05 (clinical symptoms disappeared in 1 week)NANot clear; noneNANANA
Wen 200138NAMuscle tone. I: 9.13, C: 11.80; consciousness: I: 4.37, C: 5.60Not clear; NANANANA
Yuan 199939I: 93% (28/30), C: 70% (21/30); P<0.05 (clinical symptoms and cerebral oedema disappeared in 10 days. How cerebral oedema was detected not given)NA>10 days; noneNANANA
Zhang 200040NASymptoms. I: 5 (2.9), C: 7.8 (1.2); P<0.001Not clear; noneNANARentrolental fibroplasia I: 1.6% (1/60), C: 1.8% (1/56)
  • C=control group; I=intervention group, NA=not available.

  • * Alternate patient allocation.

  • † Severity grade: I=mild, II=moderate, III=severe.