Episode 69: The Deleterious Effects of Bed Rest

The goal is to learn , inspire and bring Cardiopulm to the forefront of conversation . Thanks for joining me today and let's get after it . Hello , hello and welcome to today's episode of Talking All Things Cardiopulm . I am your host , Dr Rachele Burriesci . Before we start today's episode , I'd love to highlight our show sponsor , jane .

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Up until now , if you're in this part of the country , we have had again a wild shift in weather . We're kind of cooler and we're about to get hit with a whole bunch of storms again . But good news , the garden is popping . I have about I don't know 30 cucumbers , and the zucchinis are just about to hit .

I picked four huge ones today that were just kind of like hiding Don't know where they came from , and it's about to get started with all of the zucchini recipes . I actually made something last night that was new . It was almost like a zucchini pesto type deal Creamy zucchini pesto-y kind of thing .

If I actually do it again , though , I won't emulsify the sauce and I think I'll leave it as is , because it had such wonderful flavor on its own and I felt like I kind of lost it when it got emulsified . So we'll see . I like to try these new recipes and it's always amazing to have the fresh ingredients from the garden . It just I don't know .

The flavor is just so much more enjoyable . It tastes like the things it's supposed to taste like . So I'm super excited . I'm super excited for the tomatoes to start coming . They're still a little bit behind , but probably August they'll be showing themselves . One more garden story . Apparently , I have a set of baby bunnies under my zucchini plant .

So I was watering the garden Monday morning , I think it was and I'm watering and all of a sudden my garden bed starts crying at me . I'm not gonna lie , I am a New Yorker through and through and I still get jumpy when things either pop out at me or , you know , an unexpected sound comes from a garden box that I was not expecting .

So apparently Mama Bunny found herself another bunny B&B in our yard . She found a great spot . Thank you , miss Bunny , for not interrupting the root structure , but she literally parked her babies right next to the zucchini root . They have like a canopy umbrella over the top of them and I just have to be careful watering .

I guess because they weren't too happy either with the sound or getting sprinkled or who knows . But have to be careful . Baby bunnies are in there . Who knows ? But have to be careful . Baby bunnies are in there . Everyone's like oh , just let Rem out there . It's not my style . I am not into having to deal with that catch .

And also , rem is five years old and has never caught a bunny . She likes the game of chase , but she typically pulls up right when she could get it and I am so happy that that is my dog . Actually , the other day my mother-in-law sent me a picture .

She's like Rem found a whole nest of baby bunnies again and she's like so I think I'm going to put something over the top just to be safe . So she might have like a little motherly instinct in her . I don't know , she really has never messed with them .

She has found these nests before and she usually sticks her nose in there and kind of like you know , inhales , but she leaves them alone . We've always covered them just to not have to deal with it . But she now lays next to the nest throughout the day . So it's like she protects them and she just lets them be .

So , who knows , got a new baby bunny situation going on . It's not our first rodeo . We are literally like the bunny B&B and you know there's plenty of other things that I'll that'll take care of the , the overpopulation , that is not my job . Just going to put that out there , all right . So what did I want to talk about today ?

Today I wanted to talk about bed rest and the negative effects of bed rest . I have so many patients that ask me or tell me . I just can't believe how weak I feel or how hard this feels . Or I've only been down a few days . I feel like I have no energy . The amount of times this is said to me , I can't even tell you how many times .

So I really wanted to talk about some of the effects , because there are systemic effects that occur with bed rest . They occur just within a few days . Effects that occur with bed rest . They occur just within a few days . I'll spend most of my time talking about muscular , skeletal and cardiovascular effects , but there are many more .

But a lot of the research that has occurred with bed rest is actually on healthy individuals and typically they're actually studies done with astronauts or just young people placed on bed rest for X number of days .

So a lot of the information that comes out actually from people that go into space healthy , very fit , typically individuals , who are then in this anti-gravity environment and when they come back they have changes in muscle mass , changes in bone density , changes in posture , changes in cardiovascular system . So it's quite amazing .

But a lot of the research geared to older adults or even young adults who are , you know , in regular gravity but placed in bedrest position occur within just a few days .

Most of the studies start around the five day marker and some go until 30 days and longer , and essentially the longer the person is on bedrest , obviously the more effects that , and then the longer it takes to recover .

I have a stat or a saying in my mind and I was actually , before coming on here , looking to see if there was a research backed saying to it , and I can't find it yet , but I'm going to look for it . But I've always been told , or I have always had this verbiage of , for every one day you're in bed , it takes about three days to recover .

Now , don't hold me to that stat , but having worked in the acute care setting for 15 years , there's a lot of truth to that and it might even be more on the recovery side . So I wanted to talk about some some changes that are going to occur .

So typically , the muscular system gets hit harder than the skeletal system and you're going to see changes not only in size of muscular I'm sorry , size of muscles , but you're going to see change in strength , you're going to actually see change in electrical efficiency and you're going to have structural changes that also result in changes in muscle endurance , so you're

going to have this inefficient muscle , and certain muscles get hit harder than others . So , typically , the most affected muscle in the body is actually the plantar flexors , and it's actually funny that , um , I'm talking about this today because I had a patient the other day and they were .

They were in a position and they were starting to lose some dorsiflexion , but they really were almost not contracted , but they were stiff in the plantar flexed position and they're like I just don't know why this is so hard . Part of it is number one .

Plantar flexors are , you know , a muscle that gets strengthened in a gravity position , right Upright , and then when you're using them , you're using your own body weight against that muscle . But in the , literally in the bed , when a patient is in their comfortable resting position , what position do they rest in ?

They rest in plantar flexion , and so that can lead to a whole slew of issues , right ? And so that can lead to a whole slew of issues , right , one of which being contracture and having a plantar flexed plantar flexor .

Contracture can really be detrimental to ambulation in the long term if it's not rectified earlier , and so this is when you might bring in something like a prefo to help prevent this tightening of musculature . But it's actually the muscle that gets hit hardest with muscle change in the bedrest position

. So plantar flexors greater than dorsiflexors , plantar flexors greater than quads , and then quads greater than hamstrings . And what's the common denominator here ? It's their anti-gravity muscles . Right , we're in this anti-gravity position . They are not able to actually produce force against gravity .

Being in the bed Hamstrings , you can technically perform a heel slide and activate your hamstrings . Right , even though it's not the same , you are still able to activate . Same is true for plantar flexor , dorsiflexor . If you plantar flex in the bed , you know you can physically do that .

You're not going to get any strength benefits from it because you don't have the resistance , you don't have gravity to push against Dorsiflexion . Actually , in theory , you have some resistance . It's minimized but it's still capable of performing slightly against resistance in the bedrest position .

But there is significant change in cross-sectional area of the muscle belly and you're going to actually see change or atrophy in muscles just within five days time being on bedrest . And so what they can see in the world of showing muscular breakdown is actually increased nitrogen in the urine .

And so when you have increased nitrogen in the urine , and so when you have increased nitrogen in the urine . Essentially , what that's showing you is that we have an imbalance between protein synthesis and degradation , and so we can start seeing that by the fifth day of bed rest . When you're in bed , there are things that you can do right .

So , like in theory , you are going to utilize your upper body if you're in a wakeful state likely more efficiently than your lower body , and so bilateral upper extremity weakness is actually significantly less with bed rest compared to lower extremities .

I don't have a direct study in front of me , but I would say this would change if we have someone who is mechanically ventilated and sedated , who is unable to then activate their bilateral upper extremity .

But the moral of the story is we're going to have significant muscle changes within five days of bed rest , including decrease in cross-sectional area , decrease in efficiency of motor unit recruitment , decrease in muscle contraction size as well as time .

So you're not going to use a muscle as much or as big while being in the bed if you're in the wakeful state , and so you're going to see pretty significant changes across the board . I have a stat here 29% decrease in the estimated number of functioning motor units after five weeks of immobilization . So five weeks is considerable amount of time .

Changes can be reversed following 18 weeks of strength training . So five weeks of mobilization , 18 weeks of strength training to recover said muscle deficit . So I think the good news in all of this is that you can train and basically recover the loss of muscle deficit post-bed rest .

The one other piece I want to throw in here is most of these studies are based on healthy individuals , healthy young individuals . If you think about the astronaut type studies , typically younger people , maybe in their 30s , we'll even say 30s or 40s , who are typically physically fit .

They have to go through pretty extreme measures in order to pass , in order to become an astronaut and get cleared . Okay , but you're going to see these changes on return , despite their pre-space status . When you throw in age and comorbidities and the event that is putting the person into the hospital , that is really going to compound the overall picture .

I have another stat for you With strength in general , based on age , we have a decline in strength two to 4% per year for both men and women in adulthood . This then increases to 15% per decade in the sixth and seventh decade of life . So in your 60s and 70s you have likely a 15% decline in our muscle strength After your seventh decade .

That increases to 30% decline per decade . That increases to 30% decline per decade . Most of my patients are in their 70s and 80s .

So now we are going to include the changes that occur with age compound , that with the comorbidity compound , that , with whatever exacerbating event brought them into the hospital , and now we have to put time on top of that event brought him into the hospital and now we have to put time on top of that .

This is going to lead to more extenuating circumstances , more time to recovery . There are so many different factors that play a role here . So besides the size and strength of the muscle change , the other big piece is the motor neuron recruitment , the neural efficiency .

We know on the other side of the coin that as we start strengthening , before we increase muscle size and or strength , the first thing that improves is actually motor unit recruitment and the neural system basically becomes more efficient in its production of a contraction . Opposite is true . With bedrest we have this significant change in motor neuron recruitment .

We also have a change in fiber type . So specifically in our , our deep postural muscles that are very fiber type one fiber muscles , they're said to switch to type two X .

So now if we're thinking about , like deep postural core muscles now not being fundamentally a oxidative type muscle fiber and we're relying on type 2X , that means that we have more of an anaerobic component to it .

This is important because if you work in the acute care setting and you've had someone on bed rest who's maybe been on ECMO or IABP or an impello or on a vent for prolonged periods of time and you're that first person who's helping to assist with sitting , that activity is going to be a lot of work for a number of reasons , is going to be a lot of work

for a number of reasons and we'll get to the cardiovascular component in a second . But the actual use of postural muscles in that position is now an anaerobic activity and what you tend to find with these patients is that they get gassed out really quick . Their heart rate increases , their respiratory rate increases .

The rationale is they don't have the appropriate system involved , right , they're not utilizing oxidative fibers at this point . They might not have the appropriate oxygen gas exchange occurring peripherally to basically deal with this level of activity . This is a big task .

So when I hear and this happened recently getting someone to the edge of the bed for the first time . The goal is to walk today . Okay , everyone pump the brakes . This person has been down for two to three weeks .

They have had significant assistance to maintain a homeostatic state , including an impella , including pressors , including a heart transplant , right , like all of these things , and they've been down for three weeks . Sitting at the end of the bed is a huge deal . It's not a little deal , it's a huge deal .

So being able to articulate why this is a big deal can be helpful . Right , this person is not efficient in a number of different aspects , but this is just like a core issue , literally right . The other piece is the kinesthetic awareness , right ?

So if you've ever gotten someone up to the edge of the bed for the first time and they're almost like retro pulsing , they really can't find their body in space . This is a normal occurrence that happens with increased time in bed , that postural awareness changes because they've been in the supine position for so long .

There are articles again from astronauts who have returned from space just within a few days that have increased postural sway , gait changes and impaired kinesthetic awareness . It is going to happen Again . You compound that on top of someone who has probably many comorbidities and maybe a big hospital event and age .

You're at a high risk of falls period , right , and you haven't even gotten up yet . That kinesthetic awareness is going to take time to unravel itself , so to speak . To unravel itself , so to speak . So we have decreased musculature , we have decreased I shouldn't say decreased musculature . You have the same amount of muscles .

Decreased efficiency in your musculature , decreased size , decreased motor unit recruitment , all of the things . Decreased literal strength , decreased type one fibers throughout the body , especially those that are primarily type one type fibers . You throw that on top of . It's going to take time to regain said strength .

And those activities like sitting at the edge of the bed are a big undertaking and it's another reason why I am a true believer in bed thorax , especially for the patient who is not ready to trial sitting edge of bed .

Just getting them to get through a round of lower extremity , upper extremity exercises is a big deal and we'll have carryover to other tasks later on , and it also gives them something that they're capable of following through on when you're not in the room , which can help either expedite or prevent further deconditioning .

So lots of things that happen at the muscle system . The skeletal system gets hit too , but I want to say not as exaggerated . It takes a little bit more time but you will have change in that osteoblast versus osteoclast relationship and you will have changes in bone density . Bone density the most common or worst hit area is actually the calcaneus right .

And that makes sense too , because if you're in bed rest you're not weight bearing through your feet , but that's the number one hit spot . So this is a bigger study in time . So four months of bed rest . A bigger study in time . So four months of bed rest .

10% decrease in bone mineral density in the calcaneus , 4% in the lumbar spine and femoral neck , 2% in the tibia . No changes in the radius . Obviously that's not a weight bearing type bone anyway , but you can see changes within one week of bed rest . So one week is like that tipping point . On the other side of the coin here is that improvement piece right .

Once that person starts being against gravity , once that person is in a weight-bearing position , how much time does it take to basically undo that change ? And this specific study said after six months of ambulation post bed rest the tibia nearly returned to normal . That again only had a 2% change with that four months of bed rest .

But there was still a 2% decrease in that calcaneus , which was from 10% , and the 4% loss in the lumbar spine and femoral neck had very little improvement . So although it's maybe not as quick of a change , its effects have a longer lasting issue .

So again , if we have an older patient who now has decreased density in the spine and the hips if they were to have a fall , you're in a worse situation , right ? Higher risk for fracture . So lots of changes that occur . But let's get to the good part Cardiovascular changes , part Cardiovascular changes .

Being on bed rest , being in the bed more hours in the day than not , results in decrease in our VO2 max , decrease in our cardiac output , decrease in our stroke volume , I'm sorry increase in our resting heart rate , increase in our maximal heart rate with lower level types of activity , decrease in our oxygen delivery in the peripheral level as well , and orthostatic

hypotension . It's a huge effect of bed rest . So again , that person who has been down for X number of weeks with all of these high level end stage life-saving procedures and medications , and now we're going to get them to the edge of the bed .

We also have this orthostatic issue that you're likely going to be combating and should be aware of , because there are a number of things that essentially lead to this orthostatic change .

So a couple of things that happen , that sort of affect that list I just gave you . With bed rest you're going to have a decrease in vagal tone . With that decrease in vagal tone we have that decrease in our parasympathetic input . This is what leads to that higher resting heart rate .

With that being said , there's also increased sensitivity of norepinephrine and beta response . This is that rationale for this over-exaggerated max heart rate with lower level activity .

So you have this rapid increase in your heart rate with whatever activity that you're doing , because norepi and beta are like , hey , I'm super sensitive right now , let's get the party started right , we haven't done anything in a while . There's also a significant change in plasma volume .

So your overall volume on bed rest changes within one to two days and you actually have this rapid diuresis that occurs and with that you get a change in volume . So change in volume is going to result in decrease in preload and decrease in stroke volume , which will result in decrease in cardiac output .

Laundry lists of things that have like this extended effect . There's also changes that happen at the periphery . One of the big ones is decreased capillarization as well as decreased gas exchange , right , it's just less efficient to be able to extract the oxygen and utilize it appropriately because they haven't been doing that type of activity up until this point .

So from the orthostatic perspective there is this like significant shift in fluid that occurs from the lower extremities to the thorax and we have this change in preload , which means that response back is going to be lesser , and we have increased compliance of the lower extremity veins , so it just has less ability to return that blood quickly , right , which is also

going to decrease preload , which is further going to decrease cardiac output . And one more little piece you have decreased baroreceptor sensitivity , so that trigger in the body that's supposed to kind of regulate your blood pressure is just a little sluggish because you haven't really moved out of this position for a long , prolonged period of time .

So there are a ton of changes that occur in the system . I'll do two from the respiratory system that I think has , or maybe three that has some importance Get increased respiratory rate , which you could also lean on as part of the response to that change in muscle fiber type . You have an increased ventilation perfusion mismatch and decreased mucociliary clearance .

So if you think about the whole like pneumonia picture hospital acquired pneumonia that's where this all comes in you have a decreased total blood volume , including red blood cell mass and plasma volume .

That's huge , right , that's going to affect the preload A whole bunch of change that occur in GI , including decrease in appetite and fluid intake , which will also result in that decreased volume , decreased preload picture .

And , on the endocrine side , glucose intolerance , huge problems with glucose regulation in the hospital setting , especially when we start throwing high-level meds in the ICU . So there are a ton of changes that occur with bed rest . Now , one thing that I didn't say up front , which I think I have said in another podcast , is like the idea of bedrest .

In theory , bedrest is true , flat supine , no out of bed transfer Persons , immobilized person might have , for instance , a fracture , an unstable fracture . They're literally on bedrest flat supine , no , out of bed transfer . That's bedrest .

But when we talk about bedrest in the acute care setting , there are lots of different things that lead to being in the bed more hours in the day and some of them are actually true bedrest .

So like being on a mechanical event and being sedated and on paralytics , that person is likely down flat , supine , not activating any musculature for days and maybe even weeks . Complex traumas like I alluded to before burns grafts have very strict bedrest type schedules and positioning .

Sometimes we have surgical orders that result in bedrests , or maybe a surgical sequelae like a dural leak results in bedrest , and usually that's for short periods of time . But the bigger picture to me is the amount of time a patient spends in bed in the hospital setting . You can understand how these bedrest effects will affect that patient .

So I have a stat here . It's a 2017 set . I should probably see if I have a new one , but the quote is from an article from Baldwin et al . Patients spend the majority up to 90% of their awake hours in bed during the hospital stay , even if they can walk independently .

I cannot tell you how many patients I come across who are capable of getting themselves out of bed , capable of walking independently , who are in bed 22 out of the 24 hours in the day . There's another article , I think , that alludes to time , and I'm pretty sure the time is 22 hours in bed per day in the hospital .

That is going to result in bedrest effects . This leads to our role and communication across the board . We are number one , not the only patients that should be mobilizing . I'm sorry we are not the only professionals that should be mobilizing . I'm sorry we are not the only professionals that should be mobilizing patients in the hospital setting .

That would be one hour maybe out of a 24-hour day . It's not enough time , but we do need to understand these implications because we are part of the education process for the patient and for the hospital staff . Right , we can help patients stunt progression of muscle weakness , balance deficits and these significant cardiovascular effects .

Right , they're going to have a decrease in their VO2 max for extended period after their hospital stay . What can you do to help break that progression ? What can you teach that patient to do on their own when you're not in that room ?

And safety , right , like you , as a physical therapist , if you are a PT listening to this , or a PTA , if you are mobilizing someone , or a student , if you are mobilizing someone who has been down for X number of days , you need to be aware Not only are they going to be weak , their kinesthetic awareness is going to be significantly decreased and their

cardiovascular response is going to be significantly decreased and their cardiovascular response is going to be hypersensitive and the likelihood that they are orthostatic is very high . So you should absolutely be assessing vital signs . I'll throw a pet peeve in here because I have seen this a lot across my career and I have said this statement a lot across my career .

If you are mobilizing someone who has been in this situation , maybe they're in the ICU . Icu is a great example . Right In the ICU setting , the patient is being monitored in real time . They likely have on telly , they likely have on a pulse ox , they might have an A-line , they might also have a peripheral blood pressure cuff . Continue , swan gans . Whatever .

If that patient requires monitoring at rest , that patient should be monitored during mobilization . I do not know when the idea changed , but as a healthcare professional , you have to stand your ground .

If someone is removing said medical devices from your patient while you're mobilizing them or attempting to mobilize , you should be monitoring blood pressure , heart rate , spo2 . If that patient is on oxygen at rest , they need it . With increased mobility , upright positioning , must , must , must , must , must , must , must .

Stand your ground and if you're the person who is taking everything off so that you are more free to mobilize , stop . Part of the skill in what you're doing in that setting is assessing in real time the patient's response to activity . If you are not assessing the response to activity and you are just going and walking , that is a problem .

We have to hold our ground . We have to assess . We have to make decisions based on assess . We have to make decisions based on data and patient response . Right , I feel very strongly about this Big pet peeve of mine . That's really all I have to say about it . You got to monitor . I'm sorry . You have to keep the oxygen on .

You probably need to up titrate . You need to know if you need to up titrate , if your person needs 20 , 30 minutes to recover after your session . Something is wrong .

Right , part of your skill is assessing in real time . Part of your skill is educating your patient to make safe decisions . Part of your skill is to assess signs and symptoms and simultaneously exercise response . Sitting at the edge of the bed is exercise . Standing up for the first time is exercise .

Ambulating a short distance exercise Bed Therx , seated Therx it's exercise and for that patient it is a higher level activity and they will have a more exaggerated response and if you're not watching it , you can end up in an unsafe situation . So please , please , please , please .

Use your knowledge , use your skills , make good decisions and be part of the change and also part of the team . Okay , sorry , I get a little . A little passionate about this , this kind of stuff . All right , I hope that was helpful for you . If you found some value in this , if you learned something new , drop me some stars . Write a great review .

It is 100% appreciated . If you're looking for one-on-one mentoring , my link is in the show notes below . I would love to chat with you and help guide you on whatever topic you're interested in . All right , I hope you all have a wonderful day and whatever you have to do , get after it .