Hypovolemia
Clinical Snapshot
Hypovolemia is a generic term covering two related but distinct processes: volume depletion, the loss of sodium-containing fluid from the intravascular and interstitial (extracellular) spaces, which is more closely linked to hypotension and tachycardia; and dehydration, the loss of water from both the extracellular and intracellular spaces (for example, from excess sweating or reduced water intake), which raises plasma sodium and osmolality and may or may not cause hypotension or tachycardia. In practice the two overlap and are usually assessed and managed together under one clinical umbrella. Causes span hemorrhage; gastrointestinal, renal, skin, or respiratory fluid losses; third-space (intravascular) sequestration; and simple poor oral intake. Fluid prescribing deserves the same discipline as drug prescribing — the choice of fluid, its rate, and its volume are all part of the prescription, not an afterthought.[1]
This chapter covers the adult approach: recognizing and grading severity, distinguishing straightforward volume depletion from hemodynamically unstable hypovolemic shock, matching fluid type and rate to cause and severity, and the pharmacist-relevant medication causes of hypovolemia and the sick-day medication-hold guidance that prevents and treats them. For the pediatric approach — a different weight-based framework with its own severity scale — see Dehydration in Children.
Recognize the Condition
How hypovolemia presents
Symptoms include thirst, fatigue, muscle weakness, palpitations, and postural lightheadedness. History should identify an external source of loss — bleeding, vomiting, diarrhea, excessive diuresis, or excessive perspiration — and should include a focused medication review, since several common drug classes contribute to volume depletion (see Risk Factors). Presentation in older adults is frequently nonspecific — confusion, falls, or generalized weakness rather than classic thirst — so maintain a lower threshold to assess volume status in this group.[2]
Severity tiers of hypovolemia
Mild hypovolemia
Fluid loss under 5% of body weight (roughly under 10% of plasma volume). Usually few or no hemodynamic findings at rest; oral rehydration is typically adequate.
Moderate hypovolemia
Fluid loss of 5-10% of body weight. Postural symptoms and vital-sign changes become more likely; intravenous therapy is usually needed, or oral therapy only if reliably tolerated and closely monitored.
Severe hypovolemia and hypovolemic shock
Fluid loss over 10% of body weight. This tier overlaps with hypovolemic shock — a hemodynamically unstable emergency defined by hypotension, tachycardia, and impaired end-organ perfusion (altered mental status, reduced urine output, delayed capillary refill) — which requires immediate intravenous resuscitation and urgent identification of the underlying cause rather than a graded, stepwise approach. See Red Flags and Refer.
Physical examination findings
An increase in heart rate of more than 30 beats per minute after 1 minute of standing from a recumbent position is the most accurate single sign of moderate-to-severe volume depletion — but beta-blocker use blunts this response, so its absence does not rule out significant volume depletion in a patient taking one.[2]
A postural decline in systolic blood pressure of more than 20 mmHg suggests volume depletion; persistently low blood pressure even while supine indicates moderate-to-severe volume loss.
Dry axillae support the diagnosis; moist mucous membranes and axillae argue against it. Decreased skin turgor, prolonged capillary refill, and decreased eyeball tension are late signs that are comparatively insensitive in adults — in contrast to children, where these signs are more reliable (see Dehydration in Children) — and should not be relied on alone.
Risk Factors
- Hemorrhage — traumatic, surgical, gastrointestinal, obstetric, or otherwise.
- Gastrointestinal losses — vomiting, diarrhea, nasogastric suction, or high-output stoma/fistula drainage.
- Renal losses — osmotic diuresis (for example, from hyperglycemia), diabetes insipidus, salt-wasting nephropathy, adrenal insufficiency, or over-diuresis from diuretic therapy.
- Skin and respiratory losses — excessive sweating, fever, burns, or high ambient temperature with inadequate fluid replacement.
- Third-space (fluid sequestration) losses — pancreatitis, bowel obstruction, sepsis, major surgery, or significant hypoalbuminemia, where intravascular volume is lost into a non-functional space without any external fluid loss.
- Poor oral intake — reduced access to fluids, impaired thirst sensation, dysphagia, nausea, depression, or cognitive or mobility impairment, especially in older adults.
- Older age — blunted thirst sensation, reduced renal concentrating ability, and a higher prevalence of contributing medications and comorbidities.
- Medications that reduce intake, increase losses, or blunt the compensatory response to volume loss (see the table below).
Drugs that can alter hydration status or contribute to hypovolemia
A focused medication review is one of the highest-yield steps a pharmacist can take in a patient with unexplained or recurrent volume depletion.[2]
| Drug or drug class | Mechanism |
|---|---|
| Anticholinergics, antipsychotics, anxiolytics | Altered central thermoregulation |
| Digoxin, Fluoxetine, Metformin | Decreased appetite |
| Trihexyphenidyl | Decreased sweat production |
| ACE inhibitors, benzodiazepines, SSRIs | Decreased thirst sensation |
| Antibiotics, colchicine, laxatives, lithium, proton pump inhibitors (PPIs) | Diarrhea |
| Diuretics, SGLT2 inhibitors | Increased urine volume |
Red Flags & Refer
Any of the following changes management immediately.
- Hemodynamic instability or hypovolemic shock — hypotension, tachycardia, or altered mental status — requires urgent intravenous fluid resuscitation and immediate identification of the underlying cause; do not manage this tier with oral rehydration or a slow, stepwise fluid plan.
- Ongoing or suspected active hemorrhage as the cause of hypovolemia requires urgent surgical, endoscopic, or other procedural intervention alongside fluid and blood-product resuscitation — fluids alone do not control a bleeding source.
- Signs of severe electrolyte derangement accompanying the volume loss — for example, significant hyperkalemia, hyponatremia, or a marked acid-base disturbance.
- Inability to tolerate oral rehydration in a patient who needs fluid replacement — persistent vomiting, altered consciousness, or another barrier to safe oral intake — requires escalation to intravenous therapy rather than continued attempts at oral rehydration.
- Frank or impending hypovolemic shock in a patient with known or suspected heart failure or significant renal impairment, where standard resuscitation volumes may themselves be dangerous — involve a specialist early to balance the risk of under- and over-resuscitation.
Assessment & Diagnosis
History
- Characterize the source of loss — bleeding, vomiting, diarrhea, excessive diuresis, or excessive perspiration — and its duration and severity.
- Ask specifically about thirst, fatigue, muscle weakness, palpitations, and postural lightheadedness.
- Take a complete medication history, including nonprescription and natural health products, looking specifically for the drug classes listed in Risk Factors.
- Recognize that presentation in older adults is often nonspecific — confusion, falls, or generalized weakness rather than classic symptoms.
Physical examination
Determine the presence and severity of volume depletion and rule out hemorrhage as the cause. See Recognize the Condition for the specific findings — orthostatic heart rate and blood pressure changes, axillae, skin turgor, capillary refill — and their relative reliability in adults.
Laboratory testing
- Blood: hematocrit and albumin concentrations rise with hypovolemia, and urea rises disproportionately to creatinine. Serum sodium may be normal, low, or high, depending on the type and amount of fluid the patient has been able to consume in response to thirst.
- Urine: hypovolemia is suggested by a urine volume under 0.5 mL/kg/h, a urine sodium under 20 mmol/L, or a urine osmolality over 450 mOsm/kg. Urine specific gravity is a less accurate marker, but a value over 1.020 suggests concentrated urine and may indicate hypovolemia.
When the diagnosis is uncertain
When hypovolemia is suspected but not certain — for example, unexplained hypotension or tachycardia without an obvious history of fluid loss — a brief intravenous fluid challenge can serve as both a diagnostic test and the first step of treatment; see Choose Initial Treatment.
Treatment Targets
- Restore intravascular and extracellular volume to relieve symptoms and prevent end-organ injury.
- Identify and treat the underlying cause of volume loss — the cause determines both the fluid choice and the required rate.
- Match fluid type, rate, and route to the severity of hypovolemia and the specific losses being replaced.
- Correct or prevent associated electrolyte and acid-base disturbances without overcorrecting them.
- Avoid iatrogenic fluid overload, particularly in heart failure, significant renal impairment, and older adults.
- Identify and address medication causes of volume depletion, with a clear plan for holding and safely restarting them.
- Transition to oral intake and maintenance fluids as soon as it is safe to do so.
Choose Initial Treatment
Is hypovolemia present but uncertain?
Diagnosis uncertain give a fluid challenge of 250-500 mL of crystalloid IV over 30 minutes. Improvement in heart rate and blood pressure supports hypovolemia as the cause of the presenting hypotension or tachycardia.
Route: oral versus intravenous
Mild hypovolemia (fluid loss under 5% of body weight), tolerating oral intake oral rehydration is usually adequate — water, juice, soup broth with added salt, or a commercial oral rehydration solution.
Moderate (5-10% of body weight) or severe (over 10% of body weight) hypovolemia, or inability to tolerate oral fluids intravenous therapy is required.
Choosing the IV fluid — nonhemorrhagic hypovolemia
1st line an isotonic crystalloid — 0.9% sodium chloride or a balanced solution such as lactated Ringer's — is the first choice for initial treatment of acute hypotension and tachycardia from volume depletion; roughly one-third of each litre infused stays in the intravascular space, with the remainder redistributing to the interstitial space.
Balanced crystalloid preferred over 0.9% sodium chloride for resuscitation of critically ill adults, including those with sepsis or septic shock — current evidence and international guidance favour a balanced solution (for example, lactated Ringer's or a multi-electrolyte solution) over 0.9% sodium chloride as the default resuscitation fluid, given the risk of hyperchloremic metabolic acidosis and other harms with large-volume saline.[3][4][5][6]
Do not use dextrose 5% in water (D5W) to treat hypotension or shock — it distributes throughout total body water rather than staying intravascular, making it a poor plasma volume expander; reserve it for a pure free-water (intracellular) deficit, not for acute hemodynamic resuscitation.
Avoid colloid solutions (albumin, dextran, starch compounds) as the primary resuscitation fluid — they cost more than crystalloids without a demonstrated outcome benefit as first-line therapy; hydroxyethyl starch specifically increases the risk of acute kidney injury, need for renal replacement therapy, and mortality in critically ill patients, particularly those with sepsis, and should be avoided in this population.[7]
Resuscitation rate for nonhemorrhagic hypovolemia
Obvious hemodynamic compromise give at least 1 L of crystalloid over 30 minutes, then a second litre over the following hour, closely monitoring heart rate, blood pressure, peripheral perfusion, and jugular venous pressure for both improvement and fluid overload — delay in volume repletion risks ischemic injury and multiorgan failure. For adults with sepsis-induced hypoperfusion or septic shock specifically, give at least 30 mL/kg of crystalloid within the first 3 hours, using actual body weight (or adjusted/ideal body weight if body mass index is over 30 kg/m2), while reassessing frequently to avoid under- or over-resuscitation.[3]
Less severe hypovolemia give 250-500 mL/h of crystalloid, continuing until treatment goals are met.
Maintenance fluid, once the deficit is corrected
Maintenance fluid is given in addition to deficit replacement — approximately 30 mL/kg/day, or 2000-2500 mL/day, containing approximately 75 mmol of sodium and 50 mmol of potassium over 24 hours (for example, dextrose 3.3% with sodium chloride 0.3% with 20 mmol of potassium chloride added to each litre).
Hemorrhagic hypovolemia
1st line for active hemorrhage blood products, not crystalloid alone, are the first-choice fluid for hypotension and tachycardia from active bleeding — early transfusion over crystalloid-predominant resuscitation improves outcomes in major hemorrhage.
Balanced transfusion ratio use plasma, platelets, and red blood cells in a 1:1:1 or 1:1:2 ratio for major hemorrhage requiring massive transfusion — this achieves better hemostasis than a red-cell-predominant approach.[8]
Tranexamic acid give to any adult trauma patient with significant bleeding, or at risk of significant bleeding, within 3 hours of injury — 1 g IV over 10 minutes, followed by 1 g IV over the next 8 hours — since this reduces death from bleeding without an excess of vascular occlusive events.[9]
Burns use the Parkland formula (4 mL/kg per % total body surface area burned) to guide fluid resuscitation, with a balanced crystalloid such as lactated Ringer's as the standard initial fluid; plasma, particularly fresh frozen plasma, is a reasonable early adjunct in select burn resuscitation to help address burn-related endotheliopathy and reduce overall crystalloid requirements.
Albumin is not routinely recommended as a first-line resuscitation fluid; reserve it for specific situations (for example, large-volume paracentesis, selected cirrhosis-related complications, or crystalloid-refractory hypotension despite adequate crystalloid resuscitation) rather than using it as a default volume expander.[10]
Sick-day medication-hold guidance
During any acute illness with a real risk of dehydration or volume depletion — significant vomiting, diarrhea, fever, or reduced oral intake — temporarily hold medications that increase the risk of acute kidney injury or a drug-specific complication in the volume-depleted state: diuretics, ACE inhibitors, angiotensin receptor blockers, SGLT2 inhibitors, metformin, and NSAIDs. Give the patient (or caregiver) a specific written sick-day medication list in advance, rather than relying on them to remember this during an acute illness.[11]
Hold an SGLT2 inhibitor specifically because it increases the risk of euglycemic diabetic ketoacidosis during acute illness or reduced intake — a normal or only mildly elevated blood glucose does not rule this out in a patient taking one.
If a renin-angiotensin-aldosterone system inhibitor (ACE inhibitor, ARB, or mineralocorticoid receptor antagonist) needs to be interrupted for hyperkalemia or acute illness, restart it once the illness has resolved and volume status has normalized — do not leave it discontinued indefinitely by default, since these agents carry an independent cardiovascular and renal-protective benefit.[12]
Instruct the patient to seek medical assessment rather than continuing to self-manage if vomiting or diarrhea is frequent or unrelenting, if they cannot keep fluids down at all, if they develop confusion or reduced alertness, or if symptoms have not started improving within about 2-3 days of holding the sick-day medications.
Non-Pharmacologic Treatment
- Use correct oral rehydration technique — small, frequent volumes rather than a large volume at once — for any patient managed with oral therapy.
- Identify and treat the underlying cause directly wherever possible — for example, antiemetic therapy for vomiting, or addressing a source of excessive perspiration or fever — since fluid replacement alone does not fix an ongoing cause.
- Reassess and adjust or discontinue implicated medications (see Risk Factors and Choose Initial Treatment) as part of the treatment plan, not only as an afterthought once fluids have been given.
- Counsel on fall precautions in a patient with orthostatic symptoms until volume status has normalized, particularly in older adults.
- Weigh the patient before and after rehydration when practical — each kilogram of weight change corresponds closely to a litre of fluid, and this is a useful objective check that the estimated deficit was actually replaced.
- Educate the patient and caregivers on the specific signs that should prompt a return to care — see Red Flags and Refer.
- For a patient being sent home with sick-day medication-hold instructions, confirm they (or a caregiver) understand which medications to hold, for how long, and the specific signs that mean they should seek care rather than continue self-managing.
Special Populations
Pregnancy
Physiologic plasma volume expansion in pregnancy changes baseline vital signs, so standard adult hypotension/tachycardia thresholds should be interpreted with this in mind. Hemorrhage — for example, postpartum hemorrhage or ectopic pregnancy — is an important and time-critical cause of hypovolemia in pregnancy; manage with the same urgency as in a non-pregnant patient, with combined obstetric involvement. Isotonic crystalloid is the standard initial fluid; involve obstetric and, where relevant, anesthesia or critical care specialists early for significant hypovolemia in pregnancy.
Breastfeeding
Standard isotonic crystalloids (0.9% sodium chloride, lactated Ringer's) are compatible with breastfeeding and do not require any interruption.
Pediatrics
Not covered in this chapter — dehydration and hypovolemia in children are assessed and dosed differently, with a weight-based deficit/maintenance calculation and different severity thresholds; see Dehydration in Children.
Older adults
Thirst sensation and the compensatory tachycardic response to volume loss are both blunted with age (and further blunted by beta-blocker therapy), and presentation is frequently nonspecific — confusion, falls, or generalized weakness rather than classic symptoms — so maintain a lower threshold to assess volume status. Older adults are also more susceptible to fluid overload with standard resuscitation volumes; use smaller boluses with more frequent reassessment, and review the full medication list for contributing causes (see Risk Factors), since polypharmacy is common in this group.
Heart failure
Standard resuscitation volumes can precipitate acute decompensation. When intravenous fluid is genuinely needed, use smaller boluses (for example, 250 mL rather than a full litre), reassess frequently for signs of volume overload between boluses, and involve a specialist early for anything beyond straightforward, mild volume depletion.
Renal impairment
Avoid or use lactated Ringer's cautiously in significant renal impairment or pre-existing hyperkalemia given its potassium and lactate content; 0.9% sodium chloride avoids this specific concern but carries its own hyperchloremic-acidosis risk with large volumes. Diuretics, ACE inhibitors/ARBs, and SGLT2 inhibitors all warrant the same sick-day hold guidance in this population, often at a lower threshold given the added baseline renal risk.[12]
Monitoring & Follow-Up
Reassess heart rate, blood pressure (including postural change), peripheral perfusion, jugular venous pressure, mental status, and urine output at intervals appropriate to severity — after every bolus in significant hypovolemia, and periodically during ongoing oral or maintenance therapy. Recheck electrolytes, renal function, and acid-base status when initial derangement, ongoing losses, or large-volume resuscitation warrant it, and again after any RAAS-inhibitor or diuretic interruption before restarting it. Watch specifically for signs of fluid overload — new or worsening peripheral edema, rising jugular venous pressure, crackles on lung auscultation, or worsening oxygenation — especially in heart failure, significant renal impairment, and older adults, where the margin between under- and over-resuscitation is narrower. Weigh the patient periodically when practical as an objective check on fluid balance. Once volume status has normalized, confirm the sick-day medication list has actually been restarted — an interrupted ACE inhibitor, ARB, or SGLT2 inhibitor left off by default loses its long-term cardiovascular and renal benefit.
Common Errors to Avoid
- Using dextrose 5% in water (D5W) to treat acute hypotension or shock — it is a poor plasma volume expander and does not correct intravascular volume depletion.
- Defaulting to large-volume 0.9% sodium chloride for critically ill or larger-volume resuscitation instead of a balanced crystalloid, risking hyperchloremic metabolic acidosis.[4]
- Treating hemorrhagic hypovolemia with crystalloid alone instead of escalating early to balanced blood-product transfusion and urgent control of the bleeding source.
- Missing a medication cause of hypovolemia — over-diuresis, an SGLT2 inhibitor, or an ACE inhibitor/ARB — and treating only the fluid deficit without addressing the cause.
- Leaving a RAAS inhibitor or SGLT2 inhibitor discontinued indefinitely after a sick-day hold instead of restarting it once the illness has resolved.
- Over-aggressive fluid resuscitation in heart failure, significant renal impairment, or an older adult, precipitating fluid overload.
- Reaching for a colloid, especially a starch compound, as a routine first-line resuscitation fluid instead of crystalloid.
- Not replacing potassium losses associated with diarrhea, vomiting, or over-diuresis once fluid resuscitation is underway.
- Confusing volume depletion (sodium-containing extracellular fluid loss) with dehydration (free-water loss) and choosing a fluid that does not match the actual deficit.
- Relying on skin turgor or capillary refill alone to rule out hypovolemia in an adult — both are late, insensitive signs in this age group.
- Under-recognizing hypovolemia in an older adult who presents atypically (confusion, falls, generalized weakness) rather than with classic thirst and postural symptoms.
Clinical Decision Algorithm
Drug Tables
How to use this table: Doses are typical adult doses and require patient-specific confirmation, especially in heart failure, significant renal impairment, or older age. Select any drug name to open its complete Pharmasist Drug Database page.
Blood products
Preferred first-line fluid for active hemorrhage; use in a balanced ratio rather than a red-cell-predominant or crystalloid-predominant approach.
| Drug | Dosage | Adverse effects | Comments |
|---|---|---|---|
| Fresh frozen plasma | Major hemorrhage: Per massive transfusion protocol, balanced with platelets and red blood cells | Fluid overload; rare transfusion-related acute lung injury (TRALI) | One unit contains roughly 400-900 mg fibrinogen. Give as part of a balanced 1:1:1 or 1:1:2 ratio with platelets and red blood cells for major hemorrhage.[8] |
| Solvent/detergent-treated pooled plasma (e.g., Octaplasma) | Complex coagulation factor deficiency or massive transfusion: Per institutional protocol and coagulation status | Fluid overload; rare hypersensitivity reaction | An alternative plasma product to donor-derived fresh frozen plasma for complex coagulation factor deficiency, massive transfusion, or repeated large-volume plasma exchange. Confirm local availability before assuming interchangeability with standard fresh frozen plasma. |
| Platelets | Major hemorrhage, platelet dysfunction, or marked bleeding: Per massive transfusion protocol | Stored at 20-24 degrees C, carrying a small risk of bacterial contamination | One unit contains roughly 3 x 10^11 platelets; shelf-life 5-7 days. |
| Red blood cells | Hemorrhage: Per massive transfusion protocol, balanced with plasma and platelets | Fluid overload; rare febrile nonhemolytic transfusion reaction | Replaces or increases oxygen-carrying capacity; does not correct clotting factor or platelet deficits on its own. |
Crystalloids
| Drug | Dosage | Adverse effects | Comments |
|---|---|---|---|
| Sodium chloride 0.9% (normal saline) | Diagnostic/therapeutic fluid challenge: 250-500 mL IV over 30 minutes Less severe hypovolemia: 250-500 mL/h IV, continued until treatment goals are met Severe hypovolemia or hemodynamic compromise: At least 1 L IV over 30 minutes, then 1 L over the next hour Sepsis-induced hypoperfusion or septic shock: At least 30 mL/kg IV within the first 3 hours, using actual (or adjusted/ideal if BMI over 30 kg/m2) body weight | Fluid overload, interstitial edema, dilutional coagulopathy, hyperchloremic metabolic acidosis with large volumes (typically over 3 L), hypernatremia | Sodium 154 mmol/L, chloride 154 mmol/L. A reasonable first choice for initial treatment of acute hypotension or tachycardia from volume depletion, but a balanced crystalloid (below) is now preferred for larger-volume or critically-ill resuscitation. |
| Lactated Ringer's (balanced crystalloid) | Diagnostic/therapeutic fluid challenge: 250-500 mL IV over 30 minutes Less severe hypovolemia: 250-500 mL/h IV, continued until treatment goals are met Severe hypovolemia or hemodynamic compromise: At least 1 L IV over 30 minutes, then 1 L over the next hour Sepsis-induced hypoperfusion or septic shock: At least 30 mL/kg IV within the first 3 hours, using actual (or adjusted/ideal if BMI over 30 kg/m2) body weight | Fluid overload, interstitial edema, dilutional coagulopathy, hyponatremia; may aggravate pre-existing hyperkalemia | Contains sodium 130 mmol/L, potassium 4 mmol/L, chloride 109 mmol/L, lactate 28 mmol/L - closer to intravascular fluid composition than 0.9% sodium chloride, hence "balanced." Preferred over 0.9% sodium chloride for larger-volume or critically-ill resuscitation, including sepsis, given a lower risk of hyperchloremic metabolic acidosis.[3][4][5][6] |
| Dextrose and sodium chloride 0.9% (D5-NS) | Hypovolemia with a dehydration (free-water) component: Per individualized fluid assessment | Fluid overload, interstitial edema, dilutional coagulopathy, hyperchloremic metabolic acidosis with large volumes, hyperglycemia | Sodium 154 mmol/L plus dextrose 50 g/L. Produces comparatively smaller plasma-volume changes than 0.9% sodium chloride or lactated Ringer's alone, since the dextrose component distributes into the intracellular space once metabolized. |
| Dextrose 5% in water (D5W) | Free-water (intracellular) deficit: Per individualized fluid assessment | Interstitial edema, hyperglycemia, hyponatremia with large volumes | A poor plasma volume expander - distributes throughout total body water once the dextrose is metabolized, so very little remains intravascular. Not useful for treating acute hypotension or tachycardia; reserve for a pure free-water (intracellular) deficit. |
| Sodium chloride 0.45% (half-normal saline) | Maintenance fluid component: Per individualized maintenance calculation | Fluid overload, interstitial edema, hyperchloremic metabolic acidosis with large volumes | Sodium 77 mmol/L. Used mainly as a maintenance-fluid component, not for acute resuscitation. |
| Dextrose 3.3% with sodium chloride 0.3% (2/3-1/3) | Standard adult maintenance fluid: Approximately 30 mL/kg/day, or 2000-2500 mL/day, with potassium chloride added per individualized requirements (commonly 20 mmol/L) | Fluid overload, interstitial edema, hyperchloremic metabolic acidosis with large volumes | Sodium 51 mmol/L. A standard maintenance-fluid base once the deficit has been corrected - supplies typical daily maintenance sodium and, with added potassium chloride, potassium needs. |
| Dextrose 5% with sodium chloride 0.45% (D5-1/2NS) | Maintenance fluid, alternative base: Per individualized maintenance calculation | Fluid overload, interstitial edema, hyperchloremic metabolic acidosis with large volumes, hyperglycemia | Sodium 77 mmol/L. An alternative maintenance-fluid base to dextrose 3.3% with sodium chloride 0.3%. |
Colloids
Not recommended as a primary resuscitation fluid in current practice - see Choose Initial Treatment.
| Drug | Dosage | Adverse effects | Comments |
|---|---|---|---|
| Albumin (5% or 25%) | Selected volume-depletion or cirrhosis-related indications: Per indication-specific dosing - 5% for iso-oncotic volume replacement, 25% for a more concentrated oncotic effect | Fluid overload; rare anaphylactoid/anaphylactic reaction | Albumin 5% is roughly iso-oncotic with normal plasma and expands circulating volume by about the amount infused; albumin 25% expands plasma volume 3-4 times the infused volume. Not routinely recommended as a first-line resuscitation fluid given cost and the absence of a clear outcome benefit over crystalloid - reserve for specific indications.[10] |
| Dextran 40 | Selected volume-depletion indications: Per institutional protocol | Aggravation of bleeding, interference with blood coagulation, anaphylaxis (higher risk with higher-molecular-weight solutions) | Not commonly used as a plasma expander in current practice. |
| Hydroxyethyl starch (tetrastarch) 130/0.4 | Not recommended for routine resuscitation: Avoid in sepsis, severe liver disease, or renal impairment | Bleeding, fluid overload, liver injury, renal injury, pruritus, anaphylactoid reaction; macroamylase formation can mimic pancreatitis on blood testing | Avoid as a resuscitation fluid in critically ill patients, particularly those with sepsis or pre-existing renal impairment, given an increased risk of acute kidney injury, need for renal replacement therapy, and mortality.[7] |
Hemostatic adjunct (hemorrhagic hypovolemia)
| Drug | Dosage | Adverse effects | Comments |
|---|---|---|---|
| Tranexamic acid | Loading dose: 1 g IV over 10 minutes, within 3 hours of injury Maintenance infusion: 1 g IV over the following 8 hours | Rare venous thromboembolic events; do not give beyond the 3-hour post-injury window | Antifibrinolytic adjunct for significant traumatic hemorrhage, given alongside - not instead of - blood-product resuscitation and urgent source control.[9] |
Estimating fluid deficit and maintenance needs
Severity is expressed as a percentage of body weight, assuming each litre of fluid lost weighs 1 kg: multiply the estimated percentage deficit (see Recognize the Condition) by the current body weight in kilograms to estimate the deficit in litres. Maintenance fluid is given in addition to deficit replacement: approximately 30 mL/kg/day, or 2000-2500 mL/day, containing approximately 75 mmol of sodium and 50 mmol of potassium over 24 hours.
For burns, the Parkland formula estimates the first 24-hour crystalloid requirement as 4 mL/kg per % total body surface area burned, with half given in the first 8 hours from the time of injury and the remainder over the following 16 hours; lactated Ringer's is the standard initial fluid.
Evidence note: balanced-crystalloid preference, hydroxyethyl starch avoidance, and massive-transfusion/tranexamic-acid dosing reflect current international critical-care and trauma evidence, cross-checked against the 2026 Surviving Sepsis Campaign guideline.[3]
References
- Resuscitation fluids — New England Journal of Medicine (Myburgh JA, Mythen MG). N Engl J Med 2013;369(13):1243-1251
- The rational clinical examination: is this patient hypovolemic? — JAMA (McGee S, Abernethy WB 3rd, Simel DL). JAMA 1999;281(11):1022-1029
- Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock 2026 — Critical Care Medicine, Society of Critical Care Medicine and European Society of Intensive Care Medicine (Prescott HC, Antonelli M, Alhazzani W, et al.). Crit Care Med 2026;54(4):725-812
- Effect of Intravenous Fluid Treatment With a Balanced Solution vs 0.9% Saline Solution on Mortality in Critically Ill Patients: The BaSICS Randomized Clinical Trial — JAMA (Zampieri FG, Machado FR, Biondi RS, et al.). JAMA 2021;326(9):818-829
- Balanced Multielectrolyte Solution versus Saline in Critically Ill Adults — New England Journal of Medicine (Finfer S, Micallef S, Hammond N, et al.). N Engl J Med 2022;386(9):815-826
- Balanced Crystalloids versus Saline in Critically Ill Adults — New England Journal of Medicine (Semler MW, Self WH, Wanderer JP, et al.). N Engl J Med 2018;378(9):829-839
- Association of Hydroxyethyl Starch Administration With Mortality and Acute Kidney Injury in Critically Ill Patients Requiring Volume Resuscitation: A Systematic Review and Meta-analysis — JAMA (Zarychanski R, Abou-Setta AM, Turgeon AF, et al.). JAMA 2013;309(7):678-688
- Transfusion of Plasma, Platelets, and Red Blood Cells in a 1:1:1 vs a 1:1:2 Ratio and Mortality in Patients With Severe Trauma: The PROPPR Randomized Clinical Trial — JAMA (Holcomb JB, Tilley BC, Baraniuk S, et al.). JAMA 2015;313(5):471-482
- Effects of tranexamic acid on death, vascular occlusive events, and blood transfusion in trauma patients with significant haemorrhage (CRASH-2): a randomised, placebo-controlled trial — The Lancet (Shakur H, Roberts I, Bautista R, et al.). Lancet 2010;376(9734):23-32
- Use of Intravenous Albumin: A Guideline From the International Collaboration for Transfusion Medicine Guidelines — Chest (Callum J, Skubas NJ, Bathla A, et al.). Chest 2024;166(2):321-338
- Consensus Recommendations for Sick Day Medication Guidance for People With Diabetes, Kidney, or Cardiovascular Disease: A Modified Delphi Process — American Journal of Kidney Diseases (Watson KE, Dhaliwal K, Robertshaw S, et al.). Am J Kidney Dis 2023;81(5):564-574
- Chronic Kidney Disease in Diabetes: A Clinical Practice Guideline — Canadian Journal of Diabetes, Diabetes Canada Clinical Practice Guideline Steering Committee (Tobe SW, Bajaj HS, Tangri N, et al.). Can J Diabetes 2025;49(2):73-86
Professional reference only. Apply clinical judgment and verify patient-specific decisions against current authoritative guidance and product information.