Radiation in the ICU: How much is too much?
The use of radiation-based imaging has risen dramatically in the past decade, and medical radiation now accounts for a significant proportion of all radiation exposure in the U.S.
Critically ill patients are often subjected to many CT scans and X-rays, but who is keeping track of when enough is enough?
When he noticed one of his patients had undergone 100 X-rays, Cleveland Clinic Dr. Sudhir Krishnan was concerned.
“I said, surely, someone is keeping track of this, some regional, local, or national authority is keeping track on the amount of radiation exposure a patient typically gets," he said. "And I realized that wasn’t the case. There’s nobody.”
There is a standard federal limit for radiation dosage, but a recent Cleveland Clinic study revealed something shocking.
“Some exceeded a number of more than 100 milisiverts within these six days," Krishnan said. "By Federal Occupational Standards, that dose cannot be exceeded in five years, and we have that happening in six days.”
As patients move from different facilities, the information about the radiation they have received isn’t transferred, which could lead to bad results.
"Patients could develop a certain kind of cancer because they’ve been exposed to a certain amount of radiation,” Krishnan said.
X-rays, CT scans and fluoroscopic surgery are the most common sources of radiation. But Cleveland Clinic Dr. Charles Martin says something needs to change
“Improving communication amongst the multiple specialties to see if there’s one way to get many pieces of information from one study [is necessary],” Martin said.
Talk to your doctor about it and be sure to ask, as Krishnan suggests, "if there is no suitable alternative and is absolutely necessary, then one would have to weigh the benefits versus risk and proceed with what’s required.”
The Cleveland Clinic is working to develop a tool that tracks radiation doses and uses our electronic medical records as a home for all of this information.
TOO MUCH RADIATION IN THE ICU?
BACKGROUND: Radiation may be defined as energy traveling through space. Non-ionizing radiation is essential to life, but excessive exposures will cause tissue damage. All forms of ionizing radiation have sufficient energy to ionize atoms that may destabilize molecules within cells and lead to tissue damage.
Radiation sources are found in a wide range of occupational settings. If radiation is not properly controlled it can be potentially hazardous to the health of workers. Non-ionizing radiation is described as a series of energy waves composed of oscillating electric and magnetic fields traveling at the speed of light. Non-ionizing radiation includes the spectrum of ultraviolet (UV), visible light, infrared (IR), microwave (MW), radio frequency (RF), and extremely low frequency (ELF). Lasers commonly operate in the UV, visible, and IR frequencies. Non-ionizing radiation is found in a wide range of occupational settings and can pose a considerable health risk to potentially exposed workers if not properly controlled. Ionizing radiation sources may be found in a wide range of occupational settings, including health care facilities, research institutions, nuclear reactors and their support facilities, nuclear weapon production facilities, and other various manufacturing settings, just to name a few. These radiation sources can pose a considerable health risk to affected workers if not properly controlled.
(Source: https://www.osha.gov/SLTC/radiation/ and https://www.osha.gov/SLTC/radiation_nonionizing/index.html and https://www.osha.gov/SLTC/radiationionizing/index.html)
RISKS OF RADIATION: Most of the increased radiation exposure in the United States is due to CT scanning and nuclear imaging, which require larger radiation doses than traditional x-rays. A chest x-ray, for example, delivers 0.1 mSv (millisieverts), while a chest CT delivers 7 mSv, 70 times as much. And that's not counting the very common follow-up CT scans. The occupational federal limits are no more than 20 mSv in one year to a max of 50 mSv, but no more than 100 mSv in 5 years. Unless you were exposed to high doses of radiation during cancer treatment in youth, any increase in your risk for cancer due to medical radiation appears to be slight. But we don't really know for sure, since the effects of radiation damage typically take many years to appear, and the increase in high-dose imaging has occurred only since 1980. You will want to keep your exposure to medical radiation as low as possible and can do that in several ways. Discuss any high-dose diagnostic imaging with your clinician, keep track of your x-ray history, consider a lower-dose radiation test, consider less-frequent testing, and, don't seek out scans.
NEW STUDIES IN CELL PHONE RADIATION: The ionizing radiation given off by sources such as x-ray machines and the sun boosts cancer risk by shredding molecules in the body. But the non-ionizing radio-frequency (RF) radiation that cell phones and other wireless devices emit has just one known biological effect: an ability to heat tissue by exciting its molecules. Still, evidence advanced by the studies shows prolonged exposure to even very low levels of RF radiation, perhaps by mechanisms other than heating that remain unknown, makes rats uniquely prone to a rare tumor called a schwannoma, which affects a type of neuron (or nerve cell) called a Schwann cell. The findings “confirm that RF radiation exposure has biological effects” in rats, some of them “relevant to carcinogenesis,” says Jon Samet, a professor of preventive medicine and dean of the Colorado School of Public Health. Samet, however, cautioned the jury is still out as to whether wireless technology is similarly risky to people. Indeed, heart schwannomas are exceedingly rare in humans; only a handful of cases have ever been documented in the medical literature.