Hartmann's Solution (Lactated Ringer's Solution)

History & Origin

Hartmann's solution is named after American pediatrician Alexis Hartmann, who in 1932 modified Sydney Ringer's original saline solution. Ringer had established the importance of potassium, calcium, and bicarbonate for physiologic function in the late 19th century. Hartmann wanted an alkalinizing solution for his acidotic pediatric patients and added sodium lactate to Ringer's solution. He chose lactate rather than sodium bicarbonate because the conversion of lactate to bicarbonate was sufficiently slow to avoid the danger of rapidly shifting patients from compensated acidosis to uncompensated alkalosis.

In countries outside the USA, LR (lactated Ringer) is typically called Hartmann's solution; within the USA it is more commonly called lactated Ringer's (LR). - Sabiston Textbook of Surgery, p. 566

Composition

Compared to plasma and other common IV fluids (from Bailey & Love's Short Practice of Surgery, 28th Ed. and Morgan & Mikhail's Clinical Anesthesiology, 7th Ed.):

Component	Plasma	Hartmann's	0.9% Saline	5% Dextrose
Sodium (mmol/L)	135-145	131	154	0
Chloride (mmol/L)	95-111	111	154	0
Potassium (mmol/L)	3.5-5.3	5	0	0
Calcium (mmol/L)	2.2-2.6	2	0	0
Lactate (mmol/L)	0.5-1.0	29	0	0
Bicarbonate (mmol/L)	24-32	29*	0	0
Osmolality (mOsmol/L)	275-295	273-278	308	278
pH	7.35-7.45	5.0-7.0	4.5-7.0	3.5-5.5

*Bicarbonate equivalent provided via lactate metabolism

Classification

Hartmann's is a balanced (buffered) crystalloid solution. It belongs to the class of low-chloride crystalloids whose anionic deficit (relative to 0.9% saline) is compensated by an organic anion buffer - in this case, lactate. This gives it a strong ion difference (SID) closer to plasma than normal saline.

Pharmacokinetics / Metabolism

After infusion, lactate is metabolized predominantly by hepatic oxidation or gluconeogenesis to yield HCO3- in equimolar quantities, at a maximum rate of approximately 200 mmol/h
Only about 175-200 mL of a 1-L infusion remains intravascular after a few hours, since crystalloids distribute freely into the interstitial space
Excess water and electrolyte load is excreted more rapidly than with isotonic saline, because the transient decrease in plasma tonicity suppresses ADH secretion, permitting diuresis
Unlike normal saline, Hartmann's does not reduce plasma SID significantly and therefore does not cause hyperchloremic metabolic acidosis
Miller's Anesthesia, 10th Ed., p. 6354

Clinical Uses

Fluid resuscitation - hemorrhagic shock, trauma, surgery (preferred balanced crystalloid for most perioperative uses)
Dehydration - gastroenteritis, diarrhea; the WHO recommends Ringer's lactate / Hartmann's as the best commercially available IV solution for severe dehydration, supplying adequate Na+, K+, and lactate for acidosis correction
GI fluid losses - intestinal obstruction (replaces sodium/water losses), high ileostomy output (ml-for-ml replacement), lower GI losses
Surgical patients - standard intraoperative fluid for isotonic losses
Pediatric fluid therapy - used for resuscitation, burns, and as a replacement fluid
Burns - part of Parkland and other resuscitation protocols

Park's Textbook of Preventive & Social Medicine; Bailey & Love's Surgery 28th Ed.; Pye's Surgical Handicraft 22nd Ed.

Advantages Over Normal Saline

Feature	Hartmann's	0.9% Saline
Cl- concentration	111 mmol/L (near plasma)	154 mmol/L (supraphysiologic)
Hyperchloremic acidosis risk	Low	High with large volumes
AKI risk	Lower	Higher (chloride-rich)
Buffering capacity	Yes (via lactate)	None
Electrolyte balance	Closer to plasma	Not balanced

Large volumes of normal saline cause hyperchloremic metabolic acidosis and have been linked to perioperative acute kidney injury. Hartmann's avoids this by having a lower chloride burden and providing a bicarbonate equivalent. - Morgan & Mikhail's Clinical Anesthesiology, 7th Ed.

Precautions & Limitations

Liver failure - impaired lactate metabolism may lead to lactate accumulation
Lactic acidosis - should be used cautiously; pre-existing lactic acidosis may worsen if hepatic clearance is compromised
Hyperkalemia - contains 5 mmol/L K+; avoid or use cautiously in acute renal failure or severe hyperkalemia
Hypercalcemia - contains calcium; relevant when used with blood products (calcium can promote clotting in transfusion lines)
D-lactate - LR contains racemic (D- and L-) lactate. Theoretical concern of D-lactate encephalopathy and cardiac toxicity has not been confirmed in human studies at achievable plasma levels - Miller's Anesthesia, 10th Ed.
None of the available IV fluid solutions perfectly mirror plasma electrolyte composition; no single ideal fluid replacement exists

Recent Evidence (2023-2026)

Recent meta-analyses support the use of Hartmann's/lactated Ringer's over normal saline in specific conditions:

Acute pancreatitis: Two 2024-2025 systematic reviews (PMID 38101616, PMID 40085761) found lactated Ringer's superior to normal saline in reducing progression to moderate-to-severe acute pancreatitis
Pediatric septic shock: A 2025 meta-analysis (PMID 39891147) found balanced crystalloids (including Hartmann's/LR) comparable or superior to saline in pediatric septic shock resuscitation

Summary

Hartmann's solution is a physiologically balanced crystalloid closely approximating plasma composition. Its main advantages are a near-normal chloride concentration, buffering capacity via lactate metabolism, and lower risk of hyperchloremic acidosis compared to normal saline. It is the preferred resuscitation crystalloid in surgery, trauma, GI losses, and most perioperative settings, with caution needed in severe hepatic failure, hyperkalemia, and pre-existing lactic acidosis.

This is a shared conversation. Sign in to Orris to start your own chat.