Melting ice around a child's heart symbolizes the shift towards moderate hypothermia in pediatric heart surgery.

The Chill Factor: Rethinking Temperature Strategies in Pediatric Aortic Arch Surgery

Samir D’Costa in Health & Wellness November 2025 • 4 min read.

"Discover how moderate hypothermia is reshaping pediatric aortic arch surgery, potentially reducing risks and improving recovery times."

Aortic arch surgery in pediatric patients is a delicate balancing act. For years, deep hypothermia, a state of significantly lowered body temperature, has been a cornerstone of these procedures. This extreme cooling slows down metabolic processes, providing crucial protection to vital organs during complex operations. However, deep hypothermia isn't without its drawbacks. Clinicians have observed a range of potential complications, prompting a search for safer, more effective temperature management strategies.

Now, a new approach is gaining traction: moderate hypothermia. This technique involves cooling the body to a lesser extent, aiming to strike a balance between organ protection and minimizing adverse effects. As surgical techniques advance and regional low-flow perfusion (RLFP) becomes more refined, the question arises: can moderate hypothermia offer a viable alternative to its deeper counterpart?

A recent study published in Frontiers in Pediatrics delves into this very question, analyzing the outcomes of different temperature management strategies in pediatric aortic arch surgery. The single-center, 8-year study, led by Yuanyuan Tong and Jinping Liu, offers valuable insights into the potential benefits of moderate hypothermia. Let's explore the key findings and what they could mean for the future of pediatric cardiac care.

Decoding the Deep Dive: Understanding the Hypothermia Debate

Melting ice around a child's heart symbolizes the shift towards moderate hypothermia in pediatric heart surgery.

The study retrospectively reviewed data from 207 consecutive pediatric patients who underwent aortic arch repair with lower body circulatory arrest (LBCA) and RLFP between January 2010 and July 2017. The patients were divided into three groups based on their lowest nasopharyngeal temperature during the procedure:

Deep Hypothermia (DH): 20.0–25.0°C (68.0–77.0°F)
Moderate Hypothermia (MoH): 25.1–30.0°C (77.2–86.0°F)
Mild Hypothermia (MH): 30.1–34.0°C (86.2–93.2°F)

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The researchers then analyzed a range of outcomes, including the occurrence of acute kidney injury (AKI), length of hospital stay, neurological complications, and mortality rates. The results revealed some interesting trends. While the percentage of AKI-1 occurrences (the mildest form of AKI) was significantly higher in the mild hypothermia group compared to the deep and moderate hypothermia groups, prolonged hospital stays were decreased with elevated temperature.

The Future is Tepid: Embracing a Balanced Approach

This study offers a compelling glimpse into the potential of moderate hypothermia in pediatric aortic arch surgery. While further research is needed to fully understand the long-term effects and optimal temperature ranges, these findings suggest that a less extreme approach may offer a sweet spot, balancing organ protection with reduced complications and faster recovery times. As surgical techniques continue to evolve, the future of pediatric cardiac care may well be leaning towards a more tepid, balanced approach.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.3389/fped.2018.00356, Alternate LINK

Title: Perioperative Outcomes Of Using Different Temperature Management Strategies On Pediatric Patients Undergoing Aortic Arch Surgery: A Single-Center, 8-Year Study

Subject: Pediatrics, Perinatology and Child Health

Journal: Frontiers in Pediatrics

Publisher: Frontiers Media SA

Authors: Yuanyuan Tong, Jinping Liu, Lihua Zou, Zhengyi Feng, Chun Zhou, Ruoning Lv, Yu Jin

Published: 2018-11-27

Everything You Need To Know

What exactly is deep hypothermia and why has it been a standard practice in pediatric aortic arch surgery?

Deep hypothermia in pediatric aortic arch surgery involves significantly lowering a child's body temperature, typically to between 20.0–25.0°C (68.0–77.0°F). This extreme cooling slows down metabolic processes, providing vital organ protection during complex operations. While effective for organ preservation, deep hypothermia can lead to potential complications like acute kidney injury. The procedure requires careful balancing of the benefits and risks.

How does moderate hypothermia differ from deep hypothermia, and what is its potential role in pediatric aortic arch surgery?

Moderate hypothermia aims to strike a balance between organ protection and minimizing adverse effects by cooling the body to a lesser extent than deep hypothermia, typically to between 25.1–30.0°C (77.2–86.0°F). The goal is to provide sufficient organ protection while reducing the risks associated with extreme cooling, such as acute kidney injury and prolonged hospital stays. Regional low-flow perfusion (RLFP) is often used in conjunction with moderate hypothermia to further enhance organ protection.

How were different temperature management strategies for patients classified within the study, and what were the temperature ranges?

The study categorized patients into three groups based on their lowest nasopharyngeal temperature during the procedure: Deep Hypothermia (20.0–25.0°C), Moderate Hypothermia (25.1–30.0°C), and Mild Hypothermia (30.1–34.0°C). Analyzing outcomes across these groups allows researchers to compare the effectiveness and safety of different temperature management strategies. While the percentage of AKI-1 occurrences (the mildest form of AKI) was significantly higher in the mild hypothermia group compared to the deep and moderate hypothermia groups, prolonged hospital stays were decreased with elevated temperature.

What role does regional low-flow perfusion (RLFP) play in modern pediatric aortic arch surgery, and how does it relate to the use of moderate hypothermia?

Regional low-flow perfusion (RLFP) is a technique used in conjunction with hypothermia during pediatric aortic arch surgery to provide targeted blood flow to specific regions of the body, particularly the brain and other vital organs. This helps ensure adequate oxygen delivery and waste removal, even when the overall blood circulation is reduced due to hypothermia. Refinements in RLFP techniques are paving the way for safer and more effective use of moderate hypothermia.

What is acute kidney injury (AKI), how is it relevant to the choice of temperature management during pediatric aortic arch surgery, and how did the study evaluate this outcome across different hypothermia levels?

Acute Kidney Injury (AKI) is a potential complication following pediatric aortic arch surgery. The study found a higher incidence of AKI-1 (the mildest form) in the mild hypothermia group compared to the deep and moderate hypothermia groups, suggesting that maintaining a slightly lower temperature range may offer some renal protection. However, it's crucial to consider this finding in conjunction with other outcomes, such as neurological complications and length of hospital stay, to determine the overall optimal temperature management strategy. While the percentage of AKI-1 occurrences (the mildest form of AKI) was significantly higher in the mild hypothermia group compared to the deep and moderate hypothermia groups, prolonged hospital stays were decreased with elevated temperature.