The physiological effects of hypobaric hypoxia versus normobaric hypoxia: a systematic review of crossover trials

Coppel, Jonny; Hennis, Philip; Gilbert-Kawai, Edward; Grocott, Michael PW

doi:10.1186/s13728-014-0021-6

Extreme Physiology & Medicine

Table 3 Oxygenation and ventilation variables

From: The physiological effects of hypobaric hypoxia versus normobaric hypoxia: a systematic review of crossover trials

Outcome	Author and year	Duration of exposure (h:min)	Hypobaric hypoxia result [mean (SD)]	Normobaric hypoxia result [mean (SD)]	Difference (HH − NH)	P value	Direction of difference NH compared to HH
VE (L/min)
	Loeppky 1997	00:00	12.9	13.6	-	-	-
	Savourey 2007	00:10 build, 00:05	10.49 (2.59)	10.14 (1.51)	-	>0.05	NS
	Basualto-Alarcon 2012	00:15 build, 00:05 acclimatisation	10.5 (4.9)	10.3 (1.8)	0.2	-	-
	Basualto-Alarcon 2012	00:15 build, 00:10 acclimatisation	35.7 (5.9)	39.7 (6.7)	-4	<0.05	NH > HH
	Savourey 2003	00:10 build, 00:30	-	-	-	<0.02	NH > HH
	Savourey 2007	00:10 build, 00:30	10.70 (1.93)	10.78 (1.93)	-	>0.05	NS
	Faiss 2013	01:00	13.6 (1.8)	13.3 (3.3)	0.3	>0.05	NS
	Miyagawa 2010^a	01:05	69.2	65.6	-	>0.05	NS
	Miyagawa 2010	01:10	70.5	65.7	-	>0.05	NS
	Miyagawa 2010	01:20	73.9	70.9	-	>0.05	NS
	Miyagawa 2010	01:40	75.3	77	-	>0.05	NS
	Tucker 1983^b	02:20 including 00:15 build	2.07	4.82	−2.75	-	-
	Loeppky 1997	03:00	10.3	14.3	−4.0	<0.01	NH > HH
	Loeppky 1997	06:00	10.6	12.7	−2.1	<0.05	NH > HH
	Faiss 2013	08:00	11.8 (1.9)	14.9 (3.5)	−3.1	<0.1	NH > HH
		-	10.7 (1.8)	12.2 (1.6)	−1.5	<0.05	NH > HH
		-	12.7 (2.3)	14.2 (1.5)	−1.5	<0.1	NH > HH
	Loeppky 1997	09:00	10.2	12.2	-	<0.05	NH > HH
	Loeppky 1997	Recovery 12:00:00	9.2	10.1	-	>0.05	NS
VT (L)
	Savourey 2007	00:10 build^c, 00:05	0.72 (0.25)	0.88 (0.22)	-	0.03	NH > HH
	Basualto-Alarcon 2012	00:15 build^c, 00:05 acclimatisation	0.81 (0.36)	0.82 (0.21)	−0.01	-	-
	Basualto-Alarcon 2012	00:15 build^c, 00:10 acclimatisation	1.85 (0.56)	1.91 (0.53)	−0.06	-	NH > HH
	Savourey 2003	00:10 build^c, 00:30	-	-	-	<0.001	NH > HH
	Savourey 2007	00:10 build^c, 00:30	0.83 (0.37)	0.86 (0.34)	-	>0.05	NS
	Faiss 2013	01:00	0.88 (0.21)	0.89 (0.26)	−0.01	>0.05	NS
	Tucker 1983^b	02:20 including 00:15 build^c	106	152	-46	-	NH > HH
	Faiss 2013	08:00	0.75 (0.21)	0.94 (0.3)	−0.19	<0.05	NH > HH
	Faiss 2013	16:00	0.75 (0.23)	0.84 (0.24)	−0.9	<0.1	NH > HH
	Loeppky 1997	10:00	-	-	-	>0.05	NS
	Faiss 2013	24:00:00	0.86 (0.25)	0.95 (0.23)	−0.09	<0.05	NH > HH
Bf (cycles/min)
	Savourey 2007	00:10 build^c, 00:05	15.73 (4.64)	12.24 (3.80)	-	0.03	HH > NH
	Basualto-Alarcon 2012	00:15 build^c, 00:05 acclimatisation	13.3 (4.0)	13.4 (4.7)	−0.1	-	-
	Basualto-Alarcon 2012	00:15 build^c, 00:10 acclimatisation	20.4 (5.4)	22.3 (7.4)	−1.9	<0.05	NH > HH
	Savourey 2003	00:10 build^c, 00:30	-	-	-	<0.001	HH > NH
	Savourey 2007	00:10 build^c, 00:30	14.77 (4.17)	13.76 (4.47)	-	>0.05	NS
	Faiss 2013	01:00	16.8 (3.4)	15.9 (4.2)	−0.9	>0.05	NS
	Miyagawa 2010	01:05	31	31	-	>0.05	NS
	Miyagawa 2010	01:10	32	34	-	>0.05	NS
	Miyagawa 2010	01:20	34	36	-	>0.05	NS
	Miyagawa 2010	01:40	38	42	-	>0.05	NS
	Tucker 1983^b	02:20 including 00:15 build^c	0.9	3.8	−2.9	-	NH > HH
	Faiss 2013	08:00	16.8 (2.7)	17.1 (4.4)	−0.3	>0.05	NS
	Loeppky 1997	10:00	-	-	-	>0.05	NS
	Faiss 2013	16:00	16.1 (3)	15.8 (3.7)	−0.3	>0.05	NS
	Faiss 2013	24:00:00	16.8 (3.8)	16.2 (3.8)	0.6	>0.05	NS
PetO₂ (mmHg)
	Savourey 2007	00:10 build^c, 00:05	72.5 (6.58)	79.56 (11.94)	-	0.08	Borderline NH > HH
	Savourey 2003	00:10 build^c, 00:30	-	-	-	>0.05	NS
	Savourey 2007	00:10 build^c, 00:30	73.15 (7.16)	76.09 (11.61)	-	0.08	Borderline NH > HH
	Faiss 2013	01:00	66.4 (4.1)	62.3 (2.8)	-	4.1	NS
	Tucker 1983^b	02:20 including 00:15 build^c	−36.1	−32.6	−3.5	-	-
	Faiss 2013	08:00	61.9 (6.0)	61.6 (2.2)	0.3	>0.05	NS
	Loeppky 1997	10:00	-	-	-	>0.05	NS
	Faiss 2013	16:00	65.0 (5.4)	62.7 (2.6)	2.3	>0.05	NS
	Faiss 2013	24:00:00	65.6 (5.5)	65.6 (2.8)	0	>0.05	NS
PetCO₂ (mmHg)
	Savourey 2007	00:10 build, 00:05	44.09 (6.38)	48.87 (5.53)	-	0.05	Borderline NH > HH
	Savourey 2003	00:10 build, 00:30	-	-	-	>0.05	NS
	Savourey 2007	00:10 build, 00:30	43.43 (6.02)	46.13 (6.61)	-	>0.05	NS
	Faiss 2013	01:00	33.4 (2.5)	29.4 (2.4)	4	<0.1	HH > NH
	Tucker 1983^c	02:20 including 00:15 build	−2.8	−3.6	0.8	>0.05	NS
	Faiss 2013	08:00	33.8 (2.1)	27.5 (1.3)	6.3	<0.01	HH > NH
	Loeppky 1997	10:00	-	-	−1.6	<0.02	NH > HH
	Faiss 2013	16:00	33.1 (1.3)	27.9 (0.9)	5.2	<0.01	HH > NH
	Faiss 2013	24:00:00	30.8 (1.4)	26.5 (1.5)	4.3	<0.01	HH > NH
VA (alveolar ventilation L/min)
	Loeppky 1997	00:00	9.4	10.1	-	-	-
	Loeppky 1997	03:00	7.2	10.5	−46%	<0.05	NH > HH
	Loeppky 1997	06:00	7.6	9.1	-	<0.05	NH > HH
	Loeppky 1997	09:00	7.6	9.2	-	<0.05	NH > HH
	Loeppky 1997	Recovery 12:00:00	6.7	7.2	-	-	-
VCO₂ ml/min
	Loeppky 1997	00:00	295	333	-	-	-
	Miyagawa 2010	01:05	2188	2108	-	>0.05	NS
	Miyagawa 2010	01:10	2121	2007	-	>0.05	NS
	Miyagawa 2010	01:20	2078	2060	-	>0.05	NS
	Miyagawa 2010	01:40	2021	2082	-	>0.05	NS
	Loeppky 1997	03:00	216	330	-	<0.05	NH > HH
	Loeppky 1997	06:00	227	296	-	<0.05	NH > HH
	Loeppky 1997	09:00	235	302	−67	<0.05	NH > HH
	Loeppky 1997	Recovery 12:00	241	267	-	-	-
VO₂ consumed
	Loeppky 1997	00:00	329	340	-	-	-
	Miyagawa 2010	01:05	1709	1611	-	>0.05	NS
	Miyagawa 2010	01:10	1783	1637	-	>0.05	NS
	Miyagawa 2010	01:20	1826	1748	-	>0.05	NS
	Miyagawa 2010	01:40	1836	1840	-	>0.05	NS
	Loeppky 1997	03:00	250	361	-	<0.05	NH > HH
	Loeppky 1997	06:00	262	319	-	<0.05	NH > HH
	Loeppky 1997	09:00	278	326	-	<0.05	NH > HH
	Loeppky 1997	12:00	301	291	-	-	-
FetO₂
	Savourey 2007	00:10 build^c, 00:05	-	-	-	>0.05	NS
	Savourey 2003	00:10 build^c, 00:30	-	-	-	<0.00001	HH > NH
	Savourey 2007	00:10 build^c, 00:30	-	-	-	>0.05	NS
FetCO₂
	Savourey 2007	00:10 build, 00:05	-	-	-	>0.05	NS
	Savourey 2003	00:10 build, 00:30	-	-	-	<0.00001	HH > NH
	Savourey 2007	00:10 build, 00:30	-	-	-	>0.05	NS
Duration of inspiration/s
	Savourey 2007	00:10 build^c, 00:05	1.94 (0.65)	2.99 (0.98)	-	0.01	NH > HH
	Savourey 2007	00:10 build^c, 00:30	2.40 (1.25)	3.00 (1.16)	-	>0.05	NS
Duration of expiration/s
	Savourey 2007	00:10 build^c, 00:05	2.09 (0.87)	1.98 (0.84)	-	>0.05	NS
	Savourey 2007	00:10 build^c, 00:30	-	-	-	>0.05	NS
Hypoxic ventilatory response (HVR) 1%⁻¹
	Savourey 2007	00:10 build^c, 00:05	−0.05	0.03	-	>0.05	NS
	Savourey 2007	00:10 build^c, 00:30	−0.09	−0.07	-	>0.05	NS
SpO₂ (%)
	Savourey 2007	00:10 build^c, 00:05	83.03 (4.49)	87.11 (4.81)	−4.08	<0.05	NH > HH
	Basualto-Alarcon 2012	00:15 build^c, 00:05 acclimatisation	91.6 (4.2)	89.1 (3.8)	2.5	<0.05	HH > NH
	Basualto-Alarcon 2012	00:15 build^c, 00:10 acclimatisation	85.3 (3.8)	86.0 (1.7)	−0.7	-	-
	Savourey 2003	00:10 build^c, 00:30	-	-	-	<0.05	NH > HH
	Savourey 2007	00:10 build^c, 00:30	82.49 (4.39)	85.50 (4.84)	−2.99	0.04	NH > HH
	Faiss 2013	01:00	93 (1)	90 (3)	3	>0.05	NS
	Tucker 1983^b	02:20 including 00:15 build^c	−13.2	−13.5	0.3	>0.05	NS
	Faiss 2013	08:00	91 (3)	91 (3)	0	>0.05	NS
	Roach 1996	09:00	83% (1%)	83% (0.7%)	0	>0.05	NS
	Loeppky 2005	10:00	82%	83%	−1%	>0.05	NS
	Loeppky 1997	10:00	-	-	-	>0.05	NS
	Faiss 2013	16:00	92 (2)	91 (2)	1	>0.05	NS
	Faiss 2013	24:00:00	93 (2)	92 (1)	1	>0.05	NS
SaO₂ (%)
	Self 2011	00:05	-	-	-	0.005	NH > HH
	Savourey 2007	00:10 build^c, 00:05	-	-	-	>0.05	NS
	Savourey 2003	00:10 build^c, 00:30	85% (4)	88% (3)	−3	<0.05	NH > HH
	Savourey 2007	00:10 build^c, 00:30	81.09% (7.76)	85.48% (5.63)	−4.39	0.07	Borderline NH > HH
	Miyagawa 2010	01:05	82	83	−1	>0.05	NS
	Miyagawa 2010	01:10	81	82	−1	>0.05	NS
	Miyagawa 2010	01:20	81	82	−1	>0.05	NS
	Miyagawa 2010	01:40	82	81	1	>0.05	NS
	Roach 1996	09:00	83% (1%)	83% (0.7%)	0	>0.05	NS
PaO₂
	Self 2011	00:05	-	-	-	0.004	HH > NH
	Savourey 2007	00:10 build^c, 00:05	-	-	-	>0.05	NS
	Savourey 2003	00:10 build^c, 00:30	6.38 (0.60)	6.90 (0.86)	−0.52	≤0.05	Borderline NH > HH
	Savourey 2007	00:10 build^c, 00:30	-	-	-	>0.05	NS
CAL subjects	Naughton 1995	00:52	-	-	−1.1	>0.05	NS
Control subjects	Naughton 1995	00:52	-	-	0.7	>0.05	NS
PaCO₂
	Self 2011	00:05	-	-	-	0.005	NH > HH
	Savourey 2007	00:10 build, 00:05	-	-	-	>0.05	NS
	Savourey 2003	00:10 build, 00:30	4.65 (0.54)	5.06 (0.46)	−0.41	≤0.05	Borderline NH > HH
	Savourey 2007	00:10 build, 00:30	46.3 (6.5)	52.2 (4.2)	−5.9	0.005	NH > HH
CAL subjects	Naughton 1995	00:52	-	-	0.3	>0.05	NS
Control subjects	Naughton 1995	00:52	-	-	−0.8	>0.05	NS
Control subjects	Tucker 1983^b	02:20 including 00:15 build	−3.7	−5.6	1.9	-	-
Alveolar-arterial PO₂ difference
CAL subjects	Naughton 1995	00:52	-	-	0.7	>0.05	NS
Control subjects	Naughton 1995	00:52	-	-	0.2	>0.05	NS
Arterial O₂ content
	Savourey 2007	00:10 build^c, 00:05	-	-	-	>0.05	NS
	Savourey 2007	00:10 build^c, 00:30	-	-	-	>0.05	NS

This table lists all the values of the measured variables that relate to oxygenation and ventilation.
NS insignificant, hyphen no values given, CAL Chronic Airflow Limitation.
^aExercise started at 01:00.
^bDifference from controls.
^cWhen the subjects entered the chamber, the environmental conditions were that of normal sea level but then were gradually made more hypoxic over the specified amount of time until the target hypoxic dose was reached.

Back to article page

ISSN: 2046-7648

Contact us

General enquiries: info@biomedcentral.com