Yes. Hypothermia can happen during continuous dialysis, also called continuous renal replacement therapy (CRRT), because blood moves through tubing and a filter outside the body and can lose heat. The patient’s illness and medicines may add to the risk. In intensive care, the team checks body temperature during treatment and can use approved warming equipment or warmed fluids to help prevent or treat a drop.
How Can Continuous Dialysis Cause Hypothermia?
Continuous renal replacement therapy is a type of dialysis used mainly in intensive care for people who need kidney support over an extended period. Blood travels from the body through a tube into a filter, where waste products and excess fluid are removed before the blood returns to the patient. As blood circulates through this external system, it can lose heat to the tubing, filter, and surrounding fluids.
A review published in Kidney360 by the American Society of Nephrology identifies hypothermia as a recognized complication of CRRT. Continuous treatment can produce ongoing heat loss, and the patient's underlying critical illness may contribute to the temperature decline. Modern dialysis equipment may include warming systems to reduce this risk, although protection depends on the equipment and clinical setup.
Unlike some other forms of dialysis, CRRT usually runs for many hours and may continue around the clock. This means that even a gradual loss of heat can become important if it continues. The temperature of the treatment fluids, the operation of the warming equipment, and the patient's ability to maintain body heat all influence the overall effect.
Who Is More Likely to Develop Hypothermia During CRRT?
Not everyone receiving continuous dialysis develops hypothermia. The risk depends on several factors, including the patient's condition before treatment begins and how well their body regulates temperature. A prospective study published in the National Library of Medicine's PubMed Central found that hypothermia occurred among critically ill patients receiving CRRT and was associated with a higher likelihood of shock.
Factors that may increase the risk include:
- Severe illness or shock: These conditions can affect circulation and the body's ability to maintain a stable temperature.
- Sedation or paralytic medicines: These medicines are sometimes needed during intensive care and are among the factors associated with hypothermia in critically ill patients.
- Problems affecting temperature regulation: Certain endocrine disorders, intoxications, and injuries involving the central nervous system may contribute to difficulty maintaining body heat.
- Heat loss during treatment: The continuous movement of blood through an external circuit can add to heat loss, particularly when warming measures are insufficient for the patient's needs.
These factors can overlap. A person's temperature may fall because of CRRT, their underlying illness, or a combination of both. The clinical team considers the timing of the temperature change and the patient's overall condition when deciding what needs attention.
What Signs of Hypothermia May Occur During Continuous Dialysis?
Hypothermia is generally defined as a core body temperature below 35°C (95°F). A temperature decline during CRRT may be detected through monitoring before a person develops obvious symptoms. According to the NHS guidance on hypothermia, possible signs include shivering, cold or pale skin, unusual tiredness, confusion, slurred speech, and slow breathing.
- Shivering or appearing unusually cold.
- Cool or pale skin.
- Unusual sleepiness, tiredness, or confusion.
- Slurred speech or changes in breathing.
- Changes in heart rate or heart rhythm when the temperature falls substantially.
These signs are examples of possible effects, not a checklist for determining whether someone has hypothermia. In intensive care, sedation, severe illness, or an inability to communicate may make symptoms difficult to recognize. Measured temperature and changes from earlier readings are therefore important. If a patient or family member notices a concerning change, the bedside nurse should be informed promptly.
Can Hypothermia Affect Other Aspects of Intensive Care?
Yes. A significant fall in body temperature can affect the brain, circulation, and heart rhythm. It may also make it harder for the medical team to recognize an infection promptly if the expected rise in temperature is absent. A clinical review, Continuous Renal Replacement Therapy: Who, When, Why, and How, describes how heat loss during CRRT can mask the onset of fever.
This matters because a temperature reading must be interpreted alongside other information, including blood pressure, heart rate, breathing, laboratory findings, and changes in the patient's condition. A lower temperature does not automatically mean that dialysis is the sole cause. The team may need to consider the patient's underlying illness and other possible explanations while correcting any treatment-related heat loss.
How Do Healthcare Professionals Prevent or Treat Hypothermia During CRRT?
The intensive care team monitors body temperature and uses warming measures appropriate to the patient and the dialysis equipment. Depending on the clinical situation, these may include a blood or fluid warming device, a hospital warming blanket, and measures to reduce unnecessary exposure to cold surroundings. The team also checks that the equipment is being used according to its instructions and the prescribed treatment plan.
Evidence supports the use of appropriate active warming methods. In a prospective observational study of adults receiving CRRT, researchers reporting through the U.S. National Library of Medicine's PubMed database found that active warming approaches helped maintain body temperature more steadily than treatment without active warming. The choice of method depends on the patient, the device, and the care unit's protocol.
If a patient's temperature falls, the team may confirm the reading, review the temperature trend, check the warming system and treatment fluids, and assess for other contributing problems. Warming is guided by the patient's measured temperature and clinical condition rather than by symptoms alone. A substantial or continuing temperature decline requires timely assessment and appropriate management.
What Should Patients and Families Do If the Temperature Drops?
Patients receiving CRRT are generally monitored closely in an intensive care setting. If you are a patient who can communicate, tell your nurse if you feel unusually cold, begin shivering, or notice a new symptom. Family members should alert the bedside team if they observe unusual sleepiness, confusion, shivering, or another concerning change.
Do not alter dialysis machine settings, disconnect the circuit, stop treatment, or apply external heating devices without the care team's direction. The clinical team needs to decide whether the temperature change is related to heat loss during CRRT, another medical problem, or both. The team can then choose appropriate warming measures while maintaining the treatment needed for the patient's condition.
The key point: Hypothermia can occur during continuous dialysis, but it is a recognized complication that healthcare professionals can monitor for and address. Temperature monitoring, suitable warming equipment, and prompt assessment of a falling temperature help the intensive care team manage this risk.