Table 3. The most studied dynamic fluid responsiveness tests.

Method	Limitations	Maneuver or clinical condition	Indicates fluidresponsiveness	Sensitivity, % (95% CI)	Specificity, % (95% CI)
Central venous pressure	Right ventricular infarction or failurePulmonary hypertensionconstrictive pericarditisHypertensive pneumothorax	Decreased CVP with spontaneous inspiration	↓ ≥1 mmHg	94 (NA)	81 (NA)
Pulse pressure variation	Spontaneous ventilationCardiac arrhythmiaAcute respiratory distress syndromeRight ventricle failure	Controlled ventilation, Vt ≥ 7 mL/kg PBW	∆ ≥11%	84 (75-90)	84 (77-90)
		Increase in PPV from Vt 6-8 mL/kg PBW	­↑ ≥3.5%	94 (NA)	100 (NA)
Variation in systolic volume	Spontaneous ventilation Cardiac arrhythmia	Controlled ventilation, Vt ≥ 7 mL/kg PBW	∆ ≥13%	79 (67-87)	84 (74-90)
	Acute respiratory distress syndromeRight ventricle failure	Increase in SV variation from Vt 6-8 mL/kg PBW	­↑ ≥2.5%	88 (NA)	100 (NA)
Respiratory variation of inferior vena cava diameter	Spontaneous ventilationCardiac arrhythmiaAcute respiratory distress syndrome	Controlled ventilation, Vt ≥ 8 mL/kg PBW	∆ ≥15%	77 (44-94)	85 (49-97)
Cardiac output/cardiac index	Right ventricular infarction or failureIntrathoracic or intra-abdominal pressure >12 mmHgCardiac tamponade or tension pneumothoraxAdrenergic stimulation (pain, cough, or discomfort)	Passive lower limb raising	↑ cardiac output ≥11%	88 (80-93)	92 (89-95)
	Not intubated Unable to stop spontaneous breathing for at least 15s	End-expiratory occlusion test	↑ cardiac index ≥5%	91 (72-99)	100 (72-100)

^*If the result is negative in ventilation with low tidal volume, pulse pressure and stroke volume variations must be reassessed after a transient increase (1 min) in tidal volume to 8mL/kg. Absolute increases ≥3.5% in pulse pressure variation and ≥2.5% in stroke volume variation indicate fluid responsiveness.

∆: variation; CVP: central venous pressure; NA: not applicable; PBW: predicted body weight; SV: stroke volume; Vt: tidal volume; 95%CI: 95% confidence interval.