[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Nursing](https://durgical.com/en/nursing/) › [Critical care](https://durgical.com/en/nursing/areas/critical-care/) › Massive transfusion and the lethal triad: warming, calcium and clotting checks, and transfusion reactions

# Massive transfusion and the lethal triad: warming, calcium and clotting checks, and transfusion reactions

- Safe practice

During a massive transfusion the nurse checks every unit, warms the blood and the patient, sends repeated samples and watches for calcium loss and reactions.

Updated Nov 13, 2026

## Key points

- Products, order and amounts: according to the massive transfusion protocol.
- Temperature, pH and calcium are corrected together with the volume: hypothermia, acidosis and low calcium all worsen bleeding.
- Repeat samples every 30–60 minutes while the protocol is active: haemoglobin, blood gas, lactate, calcium, platelets, PT, aPTT and fibrinogen.
- Warm blood only in an approved blood warmer, as prescribed; never in a microwave or hot water.
- Ionised calcium falls further with each unit of red cells transfused.

## What it is

A massive transfusion protocol is a hospital plan that sends blood products quickly, in packs, to a patient who is bleeding heavily. Which products, in what order and how many are decided by the protocol and the team: on this page they are described only as «according to the massive transfusion protocol». The nurse's part is to keep the products flowing safely: identity checks on every unit, a blood warmer and a warm patient, repeated laboratory samples, close watch on temperature, calcium and clotting, recognising transfusion reactions in a patient who may not be able to speak, and complete records until the protocol is switched off.

## What it requires

- Definitions of massive transfusion vary; recent ones look at how fast blood is given over a short time, not only the total in 24 hours.
- On activation, the laboratory, blood bank and operating theatre or interventional radiology are told at once.
- Damage control resuscitation combines damage control surgery, permissive hypotension, few crystalloids and haemostatic resuscitation; the blood pressure goal is set by the team.
- Tranexamic acid, when ordered in trauma, works best in the first hour and is given only within three hours of the injury.
- The protocol is switched off when bleeding is controlled: the services are told and unused units go back to the blood bank.

## How it is applied (and why)

- When the protocol is activated, agree roles and call the blood bank and laboratory — clear communication avoids delays and waste.
- Draw and fully label the first samples at once — a labelling error stops the products.
- Check every unit at the bedside with a second person: order, identity, blood group, expiry and unit number — incompatibility causes acute haemolysis.
- Give products through a blood warmer and keep the patient covered and warm — cold worsens clotting.
- Monitor vital signs and core temperature continuously and record each unit with its time — records show trends and allow tracing.
- Send the repeat samples on time and report each result — the patient's needs change from one hour to the next.
- Watch ionised calcium and report low values; give replacement only as ordered — low calcium worsens clotting.
- Watch for reactions: fever, chills, hives, wheeze, low blood pressure, back or chest pain, breathlessness — stop the unit and call if they appear.
- When the protocol ends, return unused units, close the records and join the debrief — it improves the next activation.

## In nursing practice

- In a sedated or intubated patient, rely on vital signs, the skin, the airway pressures and the urine: the patient cannot report chills or pain.
- Transfusion-associated circulatory overload brings crackles, breathlessness, high blood pressure and distended neck veins; transfusion-related lung injury brings hypoxaemia and fever without fluid overload.
- Only normal saline may run with blood; never give medicines through the blood line.
- Hypothermia below 35 °C, pH below 7.2 and a low prothrombin ratio in the first 24 hours are the triad markers used in trauma research.

## Common mistakes

- Skipping the two-person identity check because «it is an emergency».
- Running cold products quickly without a warmer.
- Forgetting to send the repeat samples once the first products are running.
- Not reporting a low ionised calcium because the patient «looks stable».

## Test yourself

Think of the answer, then tap the question to see it.

## Which three conditions does the team correct together with volume during massive transfusion?

Temperature, pH and calcium, because hypothermia, acidosis and low calcium all worsen bleeding.

## How may blood be warmed during a massive transfusion?

Only in an approved blood warmer as prescribed, never in a microwave or hot water, which destroy the cells.

## What happens to ionised calcium as more red cells are transfused?

It keeps falling: the more units given, the lower it tends to be, so it is measured repeatedly.

## What does the nurse do first if a transfusion reaction is suspected?

Stops the transfusion, keeps the venous access with new saline tubing, checks vital signs and calls the provider, following the reaction protocol.

[Add to my cards (4)](https://durgical.app/estudiar/?add=/en/nursing/massive-transfusion-and-the-lethal-triad-warming-calcium-and-clotting-checks-and/)

## Connections

## Related 3

- [Blood transfusion: bedside checks, monitoring and reactions](https://durgical.com/en/nursing/blood-transfusion-bedside-checks-monitoring-and-reactions/)
- [The trauma patient in the ICU: the primary and secondary survey from the nursing side, the tertiary survey and complications to watch](https://durgical.com/en/nursing/the-trauma-patient-in-the-icu-the-primary-and-secondary-survey-from-the-nursing/)
- [Measuring body temperature: sites, devices and technique](https://durgical.com/en/nursing/measuring-body-temperature-sites-devices-and-technique/)

## Related conditions 3

- [Major trauma (polytrauma): ATLS primary survey](https://durgical.com/en/conditions/major-trauma-atls-primary-survey/)
- [Hypovolaemic shock](https://durgical.com/en/conditions/hypovolaemic-shock/)
- [Postpartum haemorrhage](https://durgical.com/en/conditions/postpartum-haemorrhage/)

[← All of nursing](https://durgical.com/en/nursing/)

Educational content for students; it does not replace your institution's protocols, supervised clinical training or a prescriber's order. Dose-calculation examples use made-up numbers: they are educational, not a clinical order.

Sources: [A comprehensive review of massive transfusion and major hemorrhage protocols: origins, core principles and practical implementation](https://pmc.ncbi.nlm.nih.gov/articles/PMC11808514/) (Brazilian Journal of Anesthesiology (Marinho et al.), 2025); [Transfusion-related hypocalcemia after trauma](https://pmc.ncbi.nlm.nih.gov/articles/PMC7391918/) (World Journal of Surgery, 2020); [Nursing Advanced Skills (Open RN), 3.2 Administer Blood Products: Basic Concepts](https://med.libretexts.org/Bookshelves/Nursing/Nursing_Advanced_Skills_(OpenRN)/03%3A_Administer_Blood_Products/3.02%3A_Basic_Concepts) (Open RN, Wisconsin Technical College System (LibreTexts, CC BY 4.0), 2023); [Comparison of the lethal triad and the lethal diamond in severe trauma patients: a multicenter cohort](https://pmc.ncbi.nlm.nih.gov/articles/PMC11705660/) (World Journal of Emergency Surgery, 2025).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

---
Source: https://durgical.com/en/nursing/massive-transfusion-and-the-lethal-triad-warming-calcium-and-clotting-checks-and/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/nursing/massive-transfusion-and-the-lethal-triad-warming-calcium-and-clotting-checks-and/