August 31, 2016
You're in bed, and suddenly your head starts to pound and your back pain doubles its all-around achiness. Night has blanketed the Earth and seemingly unearthed all your pain.
What's the deal?
Curious about why — or, for that matter, whether — pain seems to be more intense at night and during mornings, we reached out to Dr. Eugene Viscusi, director of acute pain management at Thomas Jefferson University Hospital, who rattled off some possibilities of why that might be.
Why do we seem to experience so much heightened pain at odd hours of the day? The morning, night, etc.
I’m not sure that is the case. There are two sides to this: There are reasons why, if you have a toothache or stiff neck, you may experience more pain. But there’s the other side of the pain cycles that counter against that. So you have to look at the [different viewpoints].
So, in the more simple terms, when nothing is distracting you and you’re trying to sleep, things bother you more. So distraction itself is a way to reduce pain. All sorts of distractions — technology, techniques, imagery, things like that. If you're doing nothing but lying there trying to sleep, then yeah, I think you focus on your pain more. So that’s perhaps one avenue. If you’re fatigued, patients who are fatigued tend to hurt more. And even in the chronic pain setting, if you don’t get adequate sleep, you tend to have exaggerated pain responses. Or if it’s colder at night, sometimes cold can be a trigger.
Why is the cold a trigger?
Because it’s just as when a warm blanket is around you, it can make you more comfortable and treat pain. A good chill might cause pain. And it’s a sort of — those nuisance things that emphasize pain. Probably one of the more common things is that when you're up and moving around, you accommodate more to pain. The positions you get into to, to try to sleep, can be uncomfortable. So if you have neck pain, back pain, sometimes just getting into bed can be very uncomfortable and your positions for sleep can be a trigger for pain.
How about coughing fits at night? Or an intensely sore throat?
They’re two separate things. So minor pains like a sore throat, I think it probably is that you’re not thinking about anything else. You’re focused only on, ‘Oh my God, I’m trying to sleep and it hurts.’ Coughing, on the other hand, people who have asthma, muscle spasms, tend to have worse spasms at night and that’s why you cough more. And that's also due to the temperature difference. It’s common in asthmatics. They typically have more wheezing at night.
The idea of distraction detracting from pain almost implies we can willfully ignore pain, right?
Sure. The other thing is, particularly when we say with chronic pain, it would make sense. Movement is kind of a good treatment for pain. People get up and move around [and] tend to feel less pain. And just being immobile tends to cause more problems. People tend to hurt more when they wake up and try to move around. It could be the lack of movement, too. But it’s speculation.
But think about some of the contrary things. The reality is, at night, let's say the hospital where you're giving a patient controlled pain release by a pump, pain requirements actually go down at night. There's a circadian rhythm with your cortisol levels that declines during night. So actually, your pain treatment requirements typically decline during the sleep hours, which is also tied into why we see respiratory deaths with opioids in those early morning hours. If you’re on high doses of opioids and your pain requirements decline, you're more likely to see respiratory events during morning hours.
The other factor is the way pain meds may be taken. If you're just taking a Percocet, opioid pain type of medicines, as those levels change over time, and you get to the end of your dose cycle, typically you don’t have enough to keep you asleep for eight hours. So we like to prescribe around-the-clock, non-narcotic pain medicine. To have at least a base of something in the background. I prefer to prescribe around-the-clock acetaminophen and nonsteroidal ibuprofen and then minimize the amount of narcotic on top of that so you have a standing base for pain relief.
But it gets more complicated when you're looking at patients at home, in the hospital, chronic versus acute pain. Not so easy.
Why does pain tolerance vary so greatly from person to person?
Not an easy question. Some of it is just how people perceive pain. Some of it could be genetic differences. Some of it could be predispositions. If you have fibromyalgia, there’s a scale that — it’s an instrument that asks a series of questions on pain sensitivity. Fibromyalgia, patients who have that tend to have high scores, but we can also administer that scale to pre-op patients and get a signal that they have increased pain sensitivity, and those patients tend to have more pain. Could that be genetic? A psychological predisposition? Is it expectations? Or is it just people have different set points for pain. Definitely, some patients have increased pain sensitivity. You can detect that with things like their response to heat or cold. So you can use, there’s a cold pressor test where you expose patients to a low temperature, and most patients will just perceive that as feeling cold. A subset will perceive as burning pain. And they tend to have a higher rate of neuropathic signaling. Another thing you can do is a hot plate test — not exactly a hot plate, but a pad that has a regulated temperature, and they've done this with hernia surgery, where they put the temperature patterns, the area where they’re going to do surgery, slowly raise the temperature and identify when the patient identifies it as painful. And patients will respond in different levels. Patients who perceive a lower thermal injury of pain have higher pain requirements later. And they also have a greater chance of pain following surgery. There’s something innate in the way we’re wired about pain sensitivity.
Sounds like getting an allergy test.
Yes. So, could we someday do provocative pain tests to assess? That could be.
Another interesting thing with opioids is we have a mix of receptors, and some patients respond differently to opioids based on the genetic population. There are potentially a lot of reasons why there's a difference. People with higher anxiety record higher levels of pain.
You can adjust expectations. Some patients who have very high expectations say, ‘This is horrible, horrific.’ Then if you can prepare them, they do better. There’s also a survey for 'catastrophizing' — that sounds crazy. But some patients will respond to challenging situations with, 'Oh my God, this is terrible; it’s going to be horrible!' Patients who catastrophize report higher levels of pain. You can actually survey that.
