1

Introduction

Administering intravenous fluids is one of the most routine and essential medical procedures carried out with three specific indications: resuscitation, replacement, and maintenance [ ]. Deciding on the amount of infused fluid in cases of replacement and resuscitation could be challenging. While the primary target of intravenous fluid administration is to improve the perfusion of body tissue, fluid overload can increase myocardium work and raise cardiac pressure, causing pulmonary edema, which is more obvious in patients with poor cardiovascular compliance [ ]. Volume overload may worsen renal function. Moreover, hypervolemia increases mean circulatory filling pressure, which is particularly important in conditions with alternate capillary permeability, such as inflammatory processes [ ]. In addition, recent studies have demonstrated that providing intravenous fluids after the initial resuscitation can result in tissue edema and exacerbate hypoxemia [ ].

The diagnosis of hypovolemia relies on the patient’s medical history, physical examination, and several clinical evaluations. A positive history of any causes of hypovolemia may assist in diagnosis, but history has little value in predicting the extent of hypovolemia. Clinical signs such as hypotension, tachycardia, oliguria, decreased skin turgor, decreased skin temperature, increased capillary refill, and decreased mental status typically appear in later stages. However, normal findings could not rule out hypovolemia, and relying solely on clinical findings may not accurately reflect the true hemodynamic status [ ]. The loss type, amount, and speed of volume loss influence the findings of a physical examination. These findings are more sensitive to hypovolemia caused by large volume losses [ ]. Additionally, some physiological and pathological variations impact the assessment of fluid status. Factors such as physiological aging, medications, and comorbidities could influence the clinical findings of hypovolemia [ ]. Laboratory findings such as blood lactate, BUN (blood urea nitrogen), fractional excretion of sodium or urea (Fe _Na , Fe _urea ), mixed venous oxygen saturation have been described. An elevated BUN/Cr ratio, low urine Na concentration, low Fe _Na , Fe _urea , and elevated serum lactate may be observed in patients with severe hypovolemia [ ]. The goals of intravenous fluid administration include optimizing effective intravascular volume and cardiac output and improving tissue perfusion and oxygen delivery. Cardiac stroke volume (SV) depends on preload (left ventricle wall stress), heart contractility, and afterload. According to the Frank-Starling law ( Fig. 1 ), the intensity of ventricular contraction depends on the resting fibers’ length. Therefore, increased left ventricular preload leads to increased SV [ ]. According to this mechanism, some static and dynamic measures were introduced to predict volume status and volume responsiveness. Since physical exams and laboratory tests aren’t very reliable for assessing volume status and cannot measure exact fluid responsiveness, an accurate evaluation of intravascular volume could assist in identifying which patients would benefit most from volume resuscitation [ ]. Some variables have been suggested for volume status measurements: central venous pressure (CVP), pulmonary artery catheterization to measure right atrial pressure and pulmonary capillary wedge pressure (PCWP), thermodilution method, ultrasound base techniques, radioimmunoassay techniques, and dynamic arterial pressure-based indices [ , ]. Hence, it is crucial to assess the effectiveness of volume resuscitation. We decided to evaluate systematic reviews assessing volume status and fluid responsiveness, with a focus on non-invasive methods.

Frank- Starling curve.

2

Methods

3

Results

The search yielded a total of 997 articles. After removing 431 duplicate entries, the reviewers screened the titles and abstracts of the remaining 566 results. They then retrieved 79 full-text articles that were deemed potentially relevant. A detailed assessment of these full texts resulted in the identification of 55 systematic reviews ( Fig. 2 ). Among these, 14 systematic reviews evaluated various methods for assessing volume status. Three systematic reviews focused on CVP, four on IVC, two on IJV, one on CCA and femoral vein, and three on lung ultrasound. Furthermore, we identified a total of 42 systematic reviews focused on evaluating fluid responsiveness (one assessing volume status and volume responsiveness simultaneously). The findings from our search and the systematic reviews included are summarized in Tables 1 and 2 .

Diagram of screening and included articles.

Table 2

Systematic reviews assessing fluid responsiveness.

Study	Articles included in SRs	Number of patients	Population characteristics	Findings
Cavallaro et al., 2010 [ ]	9	353	Adult ICU patients in shock	Alterations in CO, CI, SV, or aortic blood flow resulting from PLR are strongly associated with the rise in CO, regardless of ventilation mode, breathing, or cardiac rhythm. They had a higher predictive value than PLR-induced pulse pressure changes.
Zhang et al., 2011 [ ]	23	568	Not restricted	SV variation is valuable for predicting fluid responsiveness in different clinical situations.
Gan et al., 2013 [ ]	12	438	pediatrics	The only factor found to predict fluid responsiveness in children was the respiratory variation in the peak velocity of aortic blood flow. Static variables did not predict fluid responsiveness. Dynamic variables based on arterial blood pressure and plethysmography were not predictive.
Yang et al., 2014 [ ]	22	870	Adults under mechanical ventilation	PP variations can accurately predict fluid responsiveness.
Bang et al., 2015 [ ]	20	NS	Patients undergoing general anesthesia	Continuous automatic PP variations predict volume responsiveness effectively.
Desgranges et al., 2015 [ ]	6	163	Pediatrics under mechanical ventilation	Aortic blood flow peak velocity is a reliable method for assessing volume responsiveness.
Cherpanath et al., 2016 [ ]	23	1013	Adults	PLR is a highly effective diagnostic tool for different clinical scenarios and patient populations. Factors such as ventilation mode, fluid type, starting position, and measurement methods do not impact their diagnostic capability. However, changes in PP showed lower diagnostic performance than PLR-induced changes in flow variables, such as CO.
Monnet et al., 2016 [ ]	21	991	Adults with acute circulatory failure	CO alterations caused by PLR are highly reliable indicators of how CO will respond to volume expansion.
Messina et al., 2017 [ ]	71	3617	Critically ill patients	The fluid challenge typically involves administering 500 mL of crystalloids or colloids within a 20 to 30-min timeframe. A positive response is considered with ≥15 % cardiac output. Response assessment does not have strict criteria.
Toscani et al., 2017 [ ]	85	3601	Adults	The time taken for fluid infusion during a challenge is key to identifying fluid responders. Infusing for less than 30 min is more effective than longer durations, highlighting the standardization of the fluid challenge technique.
Pickett et al., 2017 [ ]	6	254	Critically ill patients	PLR is a weak but significant predictor of volume responsiveness.
Long et al., 2017 [ ]	17	533	Adults with acute circulatory failure	IVC ultrasound has a limited ability to measure fluid responsiveness. However respiratory variation in IVC diameter showed a better prediction ability in mechanically ventilated patients.
Piccioni et al., 2017 [ ]	7	236	Patients undergoing thoracic and cardiac surgery	PP and SV variations appear to be unreliable for forecasting fluid responsiveness in an open-chest environment during cardiothoracic surgery.
Bednarczyk et al., 2017 [ ]	13	1652	ICU patients	Dynamic assessment of fluid responsiveness using SV or PP variation was linked to a shorter duration of ICU stay, mechanical ventilation, and reduced mortality rate.
Messina et al., 2018 [ ]	35	5017	Patients undergoing general anesthesia	Implementing fluid challenge protocols in goal-directed therapy can optimize intraoperative fluid management, but PP and SV variations must be standardized.
Si et al., 2018 [ ]	12	753	Patients under mechanical ventilation	In patients with TV ≥ 8 mL/kg and PEEP ≤5 cm H 2 O, IVC respiratory variations was an accurate predictor of fluid responsiveness, while in patients with TV < 8 mL/kg or PEEP >5 cm H 2 O was a poor predictor.
Yao et al., 2018 [ ]	9	402	Patients under mechanical ventilation	The aortic blood flow peak velocity effectively measured the volume responsiveness.
Messina et al., 2019 [ ]	15	805	Adults under mechanical ventilation	The mini-fluid challenge and EEOT demonstrated strong sensitivity and specificity in predicting fluid responsiveness in the OR and the ICU.
Wang X. et al., 2019 [ ]	11	302	Children under mechanical ventilation	Respiratory variations in aortic blood flow can reliably predict fluid responsiveness, but this ability decreases in younger children <25 months.
Orso et al., 2020 [ ]	31	1709	Not restricted	IVC diameter and its respiratory variations do not seem to be reliable methods for anticipating fluid responsiveness.
Beier et al., 2020 [ ]	17	956	Not restricted	Respiratory variation in carotid peak velocity is a valuable tool for measuring volume responsiveness.
Dave et al., 2020 [ ]	11	1015	ICU patients	Dynamic SV variation assessment for fluid responsiveness leads to shorter hospital stay and decreased mortality rates.
Sanchez et al., 2020 [ ]	19	777	Adults under mechanical ventilation	PP variation had a fair performance in patients ventilated with a tidal volume ⩽8 mL.
Si et al., 2020 [ ]	13	479	Adults under mechanical ventilation	EEOT was accurate in predicting fluid responsiveness in semi-recumbent or supine patients and exhibited higher specificity in patients ventilated with low tidal volume. Its accuracy was better when hemodynamic effects were assessed by direct measurement of CI than by arterial pressure.
Gavelli et al., 2020 [ ]	13	530	ICU or operating room patients	EEOT induced changes in CO reliably detect preload responsiveness. Diagnostic performance is not influenced by the method used to assess the EEOT.
Luo et al., 2021 [ ]	6	251	Patients undergoing cardiac surgery	SV variation could serve as a reliable indicator of fluid responsiveness.
Loomba et al., 2022 [ ]	15	637	pediatrics	Fluid bolus increased arterial blood pressure or cardiac index by 10 % in about 56 % of pediatric patients, it also decreased heart rate. A better response was observed with greater age and lower cardiac index.
Azadian et al., 2022 [ ]	5	462	Adults with septic shock	There was no significant difference in mortality rates between septic shock patients who received PLR-guided resuscitation and those who underwent standard care.
Kim et al., 2022 [ ]	30	1719	Critically ill patients	IVC respiratory variations had a favorable diagnostic accuracy for predicting fluid responsiveness, although few articles were available, the area under the receiver operating characteristic curve for the IJV varied between 0.825 and 0.915. It could serve as an alternative vessel for investigation.
Huan et al., 2022 [ ]	20	854	Patients undergoing thoracic and cardiac surgery	SV variation showed good predictive performance in cardiac surgery and moderate performance in thoracic surgery.
Yenjabog et al., 2022 [ ]	27	1005	Pediatrics under mechanical ventilation	The respiratory changes in aortic peak velocity showed strong potential for diagnosing fluid responsiveness in various patient groups. PP variation could be used as an alternative as showed a high specificity. Cardiac output monitoring, electrical cardiometry, and arterial line variable parameter are useful alternatives.
Cardozo et al., 2023 [ ]	8	497	Spontaneously breathing patients	The IVC collapsibility index is a moderately accurate measure for assessing fluid responsiveness.
Carioca et al., 2023 [ ]	23	1028	93 % under mechanical ventilation	respiratory variation in inferior vena cava diameter and aortic blood flow peak velocity had moderate accuracy in predicting fluid responsiveness.
Hung et al. 2023 [ ]	11	NS	Adults	FTc showed high diagnostic accuracy in predicting perioperative hypotension and was a predictor of perioperative fluid responsiveness.
Singla et al., 2023 [ ]	10	438	Adults in critical care area	Both carotid FTc and Respiratory variation in carotid peak velocity are valuable indicators for assessing fluid responsiveness.
Shah et al., 2023 [ ]	17	618	Pediatrics in shock	CI increase >10 % predicted fluid responsiveness. SV variations and peak aortic velocity variations are accurate parameters and most useful.
Messina et al., 2023 [ ]	59	2947	Patients undergoing surgery	PP and SV variations can estimate fluid responsiveness moderately, while high tidal volume improves PP variation reliability.
Wang et al., 2023 [ ]	9	452	Patients undergoing one-lung ventilation during thoracic surgery	PP variation is not suitable for guiding intraoperative fluid therapy because it poorly predicts fluid responsiveness in this group of patients.
Walker et al., 2024 [ ]	17	842	Critically ill patients	Carotid ultrasound had moderate sensitivity and high specificity in predicting fluid responsiveness, and carotid artery peak velocity had the greatest accuracy.
Li et al., 2024 [ ]	6	256	Adults under mechanical ventilation	SV variation induced by a lung recruitment maneuver effectively indicates volume responsiveness.
Chaves et al., 2024 [ ]	40	2711	Adults under mechanical ventilation	SV and PP variations more accurately predicted volume responsiveness than the IVC collapsibility index.
Berikashvili et al., 2025 [ ]	9	560	Not restricted	Network meta-analysis demonstrated that the IVC collapsibility index was notably superior compared to other “venous” testing parameters. The caval index was significantly better than both the IJV min/max and IVCmax. Additionally, the IJV index and IVCmin significantly surpassed the IJVmin/max. The caval index was similar to the IJV index, and both indices were comparable during mechanical ventilation and spontaneous breathing.

Only gold members can continue reading. Log In or Register to continue

Share this:

• Click to share on Twitter (Opens in new window)
• Click to share on Facebook (Opens in new window)

Related

Related posts:

From algorithms to airways: Applying artificial intelligence to enhance airway assessment, management, and training Navigating the anaesthetic maze: The VATS challenge in an infant with anterior mediastinal mass Effectiveness of dipyrone (metamizole) in postoperative analgesia: A systematic review and meta-analysis Optimizing tracheostomy anesthesia: A comparative study of nerve blocks Flexible bronchoscope versus video-laryngoscope for nasotracheal intubation in patients with anticipated difficult airway under topical anesthesia and dexmedetomidine infusion: A randomized controlled trial Alternative sources for high flow nasal oxygen in low-resource settings: Exploring the potential of auxiliary oxygen ports and wall flowmeters

Stay updated, free articles. Join our Telegram channel

Join