Therapeutic Hypothermia Doubles Survival Rate and Brain Function Recovery
John Hunter (not his real name) was one of the lucky few. The 48-year-old not only survived cardiac arrest; he also walked out of HUP with no permanent brain damage. Only five percent of cardiac arrest patients have the same good fortune.
What made the difference in Hunter’s case? Therapeutic hypothermia and PennSTAR.
Slowing the Clock
Over 200,000 Americans die each year from cardiac arrest. Immediate use of CPR or a defibrillator can triple the survival rate but, as Benjamin Abella, MD, clinical research director at Penn’s Center for Resuscitation Science, explained, a successful resuscitation doesn’t always equate to a full recovery. Indeed, over 80 percent of patients die despite receiving CPR, and at least half of those who recover face a neurologic impairment or disability.
Studies show that the sudden rush of blood back through the body after resuscitation causes significant cellular damage. “The very thing that patients need most — oxygen — ends up hurting them,” Abella explained.
Therapeutic hypothermia buys the patient more time … and “makes a huge difference in outcomes.” During the life-saving process, a patient’s body temperature is cooled to 93 degrees Fahrenheit and kept at that temperature for 24 hours, an approach that both decreases inflammation and reduces brain swelling. The complex, time-intensive therapy requires specialized training and equipment … but it works. “Survival and brain function recovery can double if cooling is achieved within six to eight hours of cardiac arrest,” Abella said. “At HUP, we’ve developed a stellar cooling team to achieve this, thanks to leadership in the ED, MICU and CCU, where hypothermia therapy is implemented.”
To decrease body temperature, the patient receives an infusion of a cold saline solution and is wrapped in a specialized cooling blanket which circulates cold fluid around the body and allows precise temperature control. This last element is essential; if the body temperature drops below a certain point, the patient can go back into cardiac arrest.
Not surprisingly, the body’s natural thermostat doesn’t like the cold. Left alone, the body automatically starts shivering, which helps create warmth. To prevent this, the patient is heavily sedated and given paralyzing agents. “Shivering increases oxygen consumption and that’s what we’re trying to avoid.”
The patient remains under close surveillance in the ICU for 24 hours. Then the body temperature is slowly raised back to normal… and the outcomes have been exceptional. “Cardiac arrest is not synonymous with death,” Abella said. “If we strengthen all the links in the chain of survival – CPR and excellent post-resuscitation care -- we will save many more lives.”
Reaching Out to Save More Lives
For patients in cardiac arrest, minutes count. “It’s essential to get them here as quickly as we can after they’re resuscitated,” said Marion Leary, BSN, RN, a hypothermia coordinator who works with Abella. A collaboration with PennSTAR offered the perfect solution: expert transport care at rapid transport times.
The transfer process to HUP begins with a single call to a special hotline number. The ED staff in the originating hospital may have already begun the cooling process, with IV solutions and ice strategically placed around the patient (ie, in the arm pits, the groin area, and around the head) by the time PennSTAR arrives. On the flight back, “we maintain – or initiate -- the cooling process, making sure the brain remains as cool as possible,” said Robert Higgins, RN, NREMT-P, Flight Program manager. The flight crew keeps an especially close watch on the patient’s vital signs because of the lowered body temperature.
This collaboration is what saved John Hunter. The paramedic who resuscitated him knew about Penn’s program and called. “PennSTAR flew him here, and we quickly cooled and cared for him in the CCU,” said Daniel Kolansky, MD, CCU medical director. “He went home with full recovery to his wife and four-year-old daughter.”
Despite excellent data that support use of therapeutic hypothermia, Abella said that fewer than one-third of US hospitals have it available. PennSTAR has now extended HUP’s reach, providing life-saving therapy to the larger community. Since starting the partnership in October, “all seven patients flown to HUP for this therapy have returned home to their families intact. The results are remarkable,” Abella said.
Added Higgins, “No pun intended, but this is pretty cool stuff.”
Raghu Seethala, MD, research fellow with the Center for Resuscitation Science, lectures during the simulation component of an innovative hands-on CME course called the Hypothermia Training Institute at Penn. The course has been held twice to sold-out audiences of physicians and nurses from around the country.