Suspended Animation: Can Cooling Our Bodies To Super Low Temperatures Save Us After Deadly Trauma And Blood Loss? – Forbes

Posted: Published on November 28th, 2019

This post was added by Alex Diaz-Granados

The surgeon makes an surgeon in operation room with blood operation.

Imagine you are shot or stabbed and losing a massive amount of blood.

Simply put, your chances of survival with ongoing blood loss are slim: the likely outcome from such serious trauma is profound shock ending in cardiac arrest (the heart stops beating).

But an experimental technique that drastically lowers core body temperature in victims who have or are about to suffer a cardiac arrest could extend the window of time for trauma surgeons to repair severe and life threatening injuries.

According to a report in New Scientist last week, a team of trauma surgeons led by Dr. Samuel Tisherman at the University of Maryland School of Medicine are the first to utilize such a technique that effectively places a human into a unique state, akin to suspended animation.

By inducing profound hypothermia (lowering the core body temperature), the heart, brain and other critical organs are placed into such a standby mode, in which they do not require nearly as much oxygen, limiting damage to cells and organs.

Formally known as Emergency Preservation and Resuscitation (EPR), the goal is to rapidly cool victims of trauma who have, or are likely to suffer a cardiac arrest (due to ongoing blood loss), by replacing their entire blood volume with ice-cold saline (salt water).

The temperature achieved with this technique is bone chillingdropping the bodys core temperature to about 50 degrees Fahrenheit (normal body temp is 98.6 Fahrenheit) via an ice-cold saline solution injected into the aorta, the major blood vessel leaving the heart that supplies blood to the rest of the body.

This induced state of hypothermia effectively places the body into a state of suspended animation, almost a type of standby mode. In this state, the bodys metabolism drastically decreases, and our cells do not require as much oxygen, significantly reducing the potential for cellular damage.

The rationale is that this approach may allow extra time for surgeons to gain control of bleeding, followed by delayed resuscitation with cardiopulmonary bypass (a specialized machine that filters the blood and returns it to the patient).

Tisherman and his colleagues have already performed the procedure on at least one patient and plan to report results next month, according to the report in New Scientist.

But the long term goal is to compare EPR in an upcoming trial to standard resuscitation which would typically involve a procedure known as emergency department (ED) thoracotomy: the chest is opened with a surgical incision, the aorta (large blood vessel coming out of the heart) is cross clamped to increase blood flow to the brain, followed by open cardiac massage (manually compressing the heart to generate blood flow) .

His plan is to compare outcomes of 10 persons undergoing EPR with another 10 individuals who undergo standard resuscitation. The FDA has approved the trial obviating the need for patient consent since the injuries are presumably fatal with no alternative options for treatment.

The ED thoracotomy is a last ditch effort to save a patient of penetrating trauma who loses signs of life pulse and blood pressurewhen they arrive in the emergency department. Overall survival from such a procedure is about 10-13% in most studies, with neurologically intact survival abysmally low (2%).

Rationale for EPR

Tishermans prior research in dogs in 2005 set the stage for the human trial that is now underway. His work at the Safar Center for Resuscitation Research at the University of Pittsburgh demonstrated the feasibility of using EPR, by placing dogs into such a state of suspended animation for 2 hours, and then bringing them back to life. The results were impressive, as 12 of the 14 dogs survived.

Emergency preservation and resuscitation (EPR) is novel approach to the critically injured patient who is actively dying, explains Dr. Joseph Sakran, Director of Emergency General Surgery at Johns Hopkins Hospital, who was also a victim of gun violence when he was shot in the throat at the age of 17. The dramatic drop in body temperature slows down their physiology and may result in a situation where the time that trauma surgeons have to repair injuries goes from minutes to a few hours.

This is not the first time we have used similar concepts in medicine and surgery, cardiac surgery being one example. offered Sakran.

Targeted Temperature Management

But beyond the use of cooling employed during planned cardiac surgery that Sakran mentions, the applications of targeted temperature management (TTM) have been applied to patients with cardiac arrest and stroke over the past several decades with clinical promise. This is achieved by infusing cold saline using large bore peripheral catheters to 33-36 Celsius.

Current studies suggest TTM after cardiac arrest improves neurologically intact survival, though the exact mechanism is unclear.

Theories have focused on the neuroprotective effects of cooling, reducing injury to the blood brain barrier from toxic free radicals, as well as overall reduction in the effects of the ischemic-reperfusion injury (fresh blood mixing with blood with inflammatory compounds) after cardiac arrest and stroke. Most importantly, the avoidance of hyperthermia via reduction in metabolic requirements and demand are believed to be the most important aspect of its clinical utility.

Reality Check

Along with enthusiasm for this approach, many aspects of EPR need to be refined before this method of resuscitation becomes feasible in his view.

Dr. Tisherman has dedicated his life in caring for the trauma patient: while there are still many questions that still need to be answered, (How long can we keep patients cooled? What are the effects of reperfusion? Does it actually work?) simply getting to this point is remarkable, said Sakran.If EPR turns out to be a viable strategy in this specific patient population, it could be a game changerwe still have a long way to go before we get to that stage.

Outside of prevention which is the best medical treatment, providing a cushion of time for surgeons to fix what are often complex injuries without the patient bleeding to death may provide an opportunity for patients to have that same second chance I received at life, he added.

Excerpt from:

Suspended Animation: Can Cooling Our Bodies To Super Low Temperatures Save Us After Deadly Trauma And Blood Loss? - Forbes

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