New Time & Motion Study Highlights the Clinical Value and Sterility Concerns of Open-Basin Surgical Slush Systems

A groundbreaking time and motion study examining the use of sterile surgical slush in the operating room has just been released, offering new insights into its clinical efficacy and sterility challenges. Conducted by a team of perioperative nursing leaders across three integrated health systems, this research sheds light on the importance of slush management in optimizing tissue preservation and improving surgical outcomes, particularly in transplant and cardiac procedures.

The phrase “slush for hearts” is most likely a reference to the use of topical slush during open heart surgery to cool and protect the heart muscle. This technique is used to minimize the heart’s metabolic requirements and prevent damage. While it was once widely used, research suggests it may not provide additional cardioprotective effects beyond other cooling methods. 

In cardiac surgery, slush refers to a semi-frozen sterile saline or Ringer’s lactate solution used primarily for topical cooling of the heart and surrounding tissues during procedures like cardiopulmonary bypass (CPB) or cardiac arrest for surgery.

The study, titled “The Use of Sterile Surgical Slush in the Operating Room: A Time & Motion Study of Open-Basin Slush Units,” was led by authors Lillian H. Nicolette, MSN, RN, CNOR; Evangeline (Vangie) Dennis, MSN, RN, CNOR, CMLSO, FAORN; and Ruth P. Shumaker, MS, BSN, RN, CNOR. It evaluated 47 surgical cases from December 2024 to March 2025, focusing on the duration sterile slush remained exposed to ambient OR air and its implications for sterility.   

Key Findings:

• The average exposure time from when sterile saline was added to open-basin slush units until first use was 169 minutes (approximately 2.82 hours).
• The average duration from last slush use to case completion was 113 minutes (1.88 hours).
• Notable outliers included cases exceeding 300 minutes of exposure.
• Two cases recorded draping material leaks from open-basin systems, presenting potential sterility breaches.

Clinical Implications: Sterile surgical slush is vital for maintaining organ and tissue viability by lowering metabolic demands, minimizing ischemic injury, and reducing intraoperative bleeding. However, the extended ambient air exposure times associated with open-basin systems raise sterility concerns in light of AORN’s 2025 Guidelines for Sterile Technique, which advocate minimizing exposure time for sterile items.

Purpose of Slush in Cardiac Surgery:

• Topical Cooling with Ice Slush:

• During open heart surgery, surgeons sometimes use a cold, icy slurry (slush) to cool the heart muscle. This helps to reduce the heart’s metabolic needs and protects it from damage during the surgery. 

1. Myocardial Protection:
   1. The main reason for using slush is to induce hypothermia locally, reducing the heart’s metabolic demand and protecting myocardial tissue during ischemia (lack of blood flow).
   2. The primary goal of this cooling method is to protect the heart muscle (myocardium) from injury during the surgery, particularly when the heart is stopped and a cardioplegia solution is used. 
   3. It’s used in combination with cardioplegia (chemical arrest of the heart) to maximize myocardial protection.
2. Reduction of Tissue Injury:
   1. Lower temperatures slow cellular metabolism, helping to preserve tissue integrity during prolonged periods of interrupted blood flow.
3. Prolonged Safe Ischemic Times:
   1. Hypothermic conditions can extend the safe duration for surgeries such as valve replacements or coronary artery bypass grafting (CABG).

The research highlights a growing preference for closed-system slush technology, which offers superior sterility control, consistent temperature regulation, and reduced ambient exposure risk — critical advantages for high-acuity surgical procedures.

“Our findings support a clinical shift toward closed-system surgical slush technology, not only to optimize tissue preservation but also to uphold the highest standards in perioperative sterility,” said lead author Lillian Nicolette, MSN, RN, CNOR.

Future Recommendations: The study calls for ongoing time and motion research, detailed time tracking of surgical phases, and benchmarking against procedural standards. These efforts aim to reduce sterility risks and improve overall surgical workflow efficiency.