Evidentiary table (selected key studies only): systemic monitoring of oxygen

Reference	Patient number	Study design	Patient group	Technique assessment	End-point	Findings	Quality of evidence
Sulter, 2000	49	Prosp Obs	AIS	Pulse oximetry SpO2, ABG SatO2	Detection SatO2 < 96 %	Pulse oximetry appears useful to titrate O2 therapy	Low
Tisdall, 2008a	8	Prosp Obs	TBI	ABG PaO2 and SatO2, with PbtO2, NIRS, MD	Parameter response to raising FiO2	Raising FiO2 leads to increase of PaO2, SatO2, PbtO2, NIRS rSO2, and reduction of MD lactate/pyruvate ratio, i.e., ABG O2 monitoring is plausibly reflected by cerebral oxygenation monitoring	Low
Diringer, 2007	5	Prosp Obs	TBI	ABG PaO2 with PbtO2, PET CBF and CMRO2	Parameter response to raising FiO2	Raising FiO2 leads to increase of PaO2 and PbtO2, while PET CBF and CMRO2 remain unchanged, i.e., ABG O2 monitoring is not reflected by all parameters of cerebral oxygenation	Low
Zhang, 2011	9	Prosp Obs	ICH, TBI, SAH	ABG PaO2/FiO2 with ICP, CPP	Parameter response to raising PEEP	Raising PEEP leads to improvement of pulmonary oxygenation, to increase of ICP, and decrease of CPP	Low
Koutsoukou, 2006	21	RCT	ICH, TBI	ABG PaO2/FiO2 with lung mechanics parameters	Lung mechanics in PEEP versus NoPEEP	Improvement of pulmonary oxygenation (assessable by ABG O2 monitoring) and lung mechanics in PEEP compared to No PEEP group	Moderate
Muench, 2005	10	Prosp Obs	SAH	ABG PaO2/FiO2 with CPP, PbtO2	Parameter response to raising PEEP	Raising PEEP leaves pulmonary oxygenation unchanged and leads to decrease in CPP and PbtO2, i.e., no strong correlation between systemic and cerebral O2 monitoring	Low
Wolf, 2005	13	Prosp Obs	SAH, TBI	ABG SatO2 and PaO2, with FiO2, PbtO2	Long-term response of systemic and cerebral oxygenation to raising PEEP	Raising PEEP allows reduction of FiO2 after 24 h and is associated with increased PbtO2, i.e., ABG O2 monitoring reflects improved long-term cerebral oxygenation	Low
Bein, 2002	11	Prosp Obs	TBI, ICH, SAH	ABG PaO2 and SatO2 with CPP, SjvO2	Response of systemic and cerebral oxygenation/perfusion to raising ventilator pressure	Raising peak pressure leads to increased PaO2 and SatO2, while CPP and SjvO2 are decreased, i.e., ABG O2 monitoring might not reflect net cerebral oxygenation	Low
Nemer, 2011	16	RCT	SAH	ABG PaO2/FiO2 with ICP, CPP	Oxygenation and cerebral pressure response to two different recruitment maneuvers	PV recruitment leads to improved pulmonary oxygenation (reflected by ABG O2 monitoring) and leaves ICP and CPP unaffected as compared to CPAP recruitment	Moderate
Nekludov, 2006	8	Prosp Obs	TBI, SAH, ICH	ABG PaO2 with MAP, ICP, CPP	Systemic oxygenation and cerebral pressures response to proning	Prone positioning leads to improved pulmonary oxygenation (as reflected by ABG O2 monitoring), to a slight increase in ICP, a stronger increase in MAP and hence a net increase in CPP	Low
Davis, 2009	3,420	Retrosp	TBI	AGB PaO2	Mortality	Higher mortality both in hypoxemia and extreme hyperoxemia, as reflected by AGB PaO2 on admission	Low
Davis, 2004a	59	Prosp Obs	TBI	Pulse oximetry SpO2	Mortality, ‘‘good outcome’’	Pulse oximetry useful to detect outcome-relevant desaturation	Low
Pfenninger, 1991	47	Prosp Obs	TBI	ABG PaO2	Correlation of pre-hospital PaO2 with level of consciousness	PaO2 only weakly correlated with GCS (r = 0.54)	Low