Is there evidence to support the use of cold intravenous (IV) fluids in treating hyperthermia?

From the Guidelines

The use of cold intravenous (IV) fluids is a recommended treatment for hyperthermia, as evidenced by the administration of 2000-3000 ml of chilled (4°C) 0.9% saline at IV, as suggested by the European Malignant Hyperthermia Group 1.

Key Points to Consider

• Cold IV fluids can be used to rapidly reduce core body temperature in hyperthermic patients, particularly in emergency situations such as heat stroke, malignant hyperthermia, or neuroleptic malignant syndrome.
• The mechanism of cold IV fluids works through direct heat exchange, as the cold fluid absorbs heat from the body's core as it circulates through the bloodstream.
• This method is advantageous because it provides simultaneous rehydration while addressing the temperature elevation, addressing two critical issues in hyperthermia management.
• Cold IV fluids are most effective when used as part of a comprehensive cooling strategy that may include external cooling methods.
• However, caution should be exercised in patients with cardiac or renal impairment, as rapid fluid administration may exacerbate these conditions.
• The technique is generally considered safe and effective when appropriate volumes are used and vital signs are closely monitored during administration, as noted in the guidelines for post-cardiac arrest care 1.

Important Considerations

• The optimal volume and rate of administration of cold IV fluids may vary depending on the individual patient's needs and medical condition.
• It is essential to continuously monitor the patient's core temperature and vital signs during the administration of cold IV fluids.
• Other cooling methods, such as surface cooling devices, fans, and ice packs, may be used in conjunction with cold IV fluids to achieve optimal cooling.
• The European Malignant Hyperthermia Group recommends stopping cooling once the temperature is less than 38.5°C 1.
• The use of cold IV fluids in the prehospital setting may be beneficial, but it is crucial to consider the potential risks and benefits, as noted in the international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science 1.

From the Research

Evidence for Cold IV Fluids in Hyperthermia

• There are studies that investigate the use of cold intravenous (IV) fluids in treating hyperthermia, with varying results 2, 3, 4, 5.
• A 2023 study found that cold IV saline infusion resulted in a significantly greater cooling rate compared to passive cooling, but the authors cast doubt on its effectiveness for whole-body cooling of hyperthermic individuals 2.
• A 2010 study demonstrated that cold IV saline infusion combined with ice packs is effective in inducing and maintaining therapeutic hypothermia after cardiac arrest 3.
• A 2008 study found that rapid infusion of cold saline solution resulted in a 1°C cooling of core body temperature, but did not induce a therapeutic plane of hypothermia 4.
• A 2018 study found that intravenous cold saline was effective in reducing core temperature in hyperthermic athletes, with body composition having a significant impact on overall cooling 5.

Key Findings

• Cold IV saline infusion can result in a significant cooling rate, but its effectiveness for whole-body cooling is questionable 2.
• Cold IV saline infusion can be effective in inducing and maintaining therapeutic hypothermia after cardiac arrest 3.
• Rapid infusion of cold saline solution can result in a 1°C cooling of core body temperature, but may not be sufficient to overcome thermoregulatory responses 4.
• Body composition can impact the effectiveness of cold IV saline infusion for cooling hyperthermic individuals 5.

Study Limitations

• The studies had small sample sizes and varying methodologies, which may limit the generalizability of the results 2, 3, 4, 5.
• Some studies had conflicting results, highlighting the need for further research to fully understand the effectiveness of cold IV fluids in treating hyperthermia 2, 5.