Studies evaluating preload in acute brain injury patients

Reference	Patient number	Study design	Group	Technique assessment	End-point	Findings	Quality of evidence
Role of preload monitoring to explain the mechanisms of brain injury-related cardiopulmonary complications
Deehan et al. [38]	24	R	SAH	PAC	To assess effects of dobutamine	High variable PAOP in patients with PE	Very low
Watanabe et al. [34]	34	P	SAH	TT	To evaluate which hemodynamic variable was associated with the occurrence of PE	PE was associated with higher GEDVI DCI was associated with lower GEDVI	Very low
Mayer et al. [45]	72	R	SAH	Echography	To evaluate the impact of hemodynamic alterations on cerebral complications	PAOP was not associated with the development of DCI	Very low
Vespa et al. [39]	56	R	SAH	PAC	To evaluate the mechanisms of poor oxygenation after SAH	Increased ELVWI in patients with poor oxygenation	Very low
Touho et al. [44]	25	R	SAH	TT	To evaluate the mechanisms of poor oxygenation after SAH	Increased intrapulmonary shunt and ELWI were found in patients with poor oxygenation	Very low
Sato et al. [37]	49	P	SAH	TT	To assess variables related to the development of PE	Patients with PE had higher ELWI than others	Low
Verein et al. [117]	17	P	Stroke	TT	To assess the relationship between ELVWI and ICP or brainstem function	ELVWI was correlated with latency of auditory potentials	Very low
Role of preload monitoring to optimize therapy
Bulters et al. [56]	71	RCT	SAH	PAC	To assess hemodynamic changes with IABP	PAOP-guided therapy resulted in increased CBF and CPP during IABP	Moderate
Mutoh et al. [111]	7	P	SAH	TT	To assess the effects of hyperdynamic therapy on cerebral oxygenation during s-VSP	Increased CO was associated with improved cerebral oxygenation	Very low
Preload monitoring findings and outcome
Mutoh et al. [78]	45	P	SAH	TT	To evaluate the effects of TT-guided therapy on DCI occurrence during VSP	4/8 DCI in patients with VSP No pulmonary edema or heart failure	Low
Kim et al. [67]	453	P (b/a)	SAH	PAC HHH versus HD	To compare the effects of two therapeutic strategies on neurological outcomes	Reduced incidence of sepsis and pulmonary edema Reduced mortality	Moderate
Mutoh et al. [68]	116	RCT	SAH	PAC (late) TT	To compare the effects of two therapeutic strategies on neurological outcomes	Reduced VSP, DCI, VSP-related infarctions, CV complications—improved mRS	Moderate

P prospective, R retrospective, SAH subarachnoid haemorrhage, TT transpulmonary thermodilution, PE pulmonary edema, LVEF NPE neurogenic pulmonary edema, NR not reported, HHH triple-H therapy, PAC pulmonary artery catheter, HD hyperdynamic therapy, CI cardiac index, GEDV global end-diastolic volume, ELVWI extravascular lung water index, DCI delayed cerebral ischemia, VSP vasospasm, s-VSP symptomatic vasospasm, CV cardiovascular, PAOP pulmonary artery occlusive pressure, IABP intra-aortic balloon counterpulsation

TT-guided therapy consisted in optimizing CI, GEDV, and reducing EVLWI