Categories
Procedure Areas

Should Physician Assistants and Nurse Practitioners Perform Colonoscopy?

As I prepared to write this post and discussed it with my colleagues, there were only two responses: this is a great idea and this is a horrible idea. When it comes to abdicating physician clinical responsibilities to advance practice providers, there just is no more polarizing topic in medicine. And the performance of colonoscopy is the most polarizing of the polarizing.

30 years ago, non-surgical procedures were the realm of the physician. As a resident, I was trained in and expected to be able to perform bone marrow biopsies, central venous catheters, endotracheal intubation, flexible sigmoidoscopy, lumbar punctures, and paracenteses. But these procedures have largely disappeared from the portfolio of today’s residency training programs and are now frequently relegated to non-physician practitioners. Recently, our medical center rolled out a bedside procedure team staffed by nurse practitioners who perform central line placement, thoracentesis, lumbar puncture, and paracentesis. Nurse practitioners do nearly all of the bone marrow biopsies in our hospital. Across the country, nurse midwives perform deliveries, respiratory therapists do endotracheal intubation, and physician assistants place dialysis catheters. One of the last bastions of physician-performed procedures is the screening colonoscopy. But should colonoscopy go the way of central lines and bone marrow biopsies? This was the subject of a recent pro and con article in AGA Perspectives publication of the American Gastroenterological Association.

How Many Screening Colonoscopies Need To Be Done Each Year?

Colon cancer occurs in 4.4% of American men and 4.1% of American women. One-third of people who get colon cancer will die of it. Most colon cancers arise from colon polyps and it takes about 10 years for a polyp to turn into a cancer. 30% of American men and 20% of American women will develop a colon polyp at some time during their lives. Screening colonoscopy can identify colon polyps before they turn into cancer and allow for removal of the polyp, thus preventing colon cancer. The current recommendations are for every American to have screening colonoscopy every 10 years from age 50 through age 75. If a polyp is found, then screening should be increased to every 5 years. If a person has a first-degree relative with colon cancer, then screening should start at age 40 and occur every 5 years. When you do the math it works out that:

  1. The average low-risk American should get 3 colonoscopies during a lifetime (66% of Americans).
  2. The average American with a polyp should get 6 colonoscopies during a lifetime (22% of Americans).
  3. The average American with a family history of colon cancer should get 8 colonoscopies during a lifetime (12% of Americans)

Doing additional math, overall, the average American should get 4.3 colonoscopies during a lifetime. Based on the age demographics from the 2016 U.S. Census, on any given year, 4,235,000 Americans should be getting their first colonoscopy and 17,881,000 Americans should be getting a follow-up colonoscopy. Adding these numbers up, if we were to optimally screen every American for colon cancer, we would need to do a total of 22 million screening colonoscopies every year.

Screening colonoscopy is primarily done by gastroenterologists and general surgeons. Currently in the United States, there are 14,000 gastroenterologists and 25,000 general surgeons. If all screening colonoscopy was done by gastroenterologists, then the average gastroenterologist would need to do 1,571 screening colonoscopies per year to completely cover the needs. If screening colonoscopy is done by both gastroenterologists and general surgeons, then they would need to do 637 per year on average. In reality, these numbers are way over-inflated because there will always be Americans who adamantly refuse to undergo colonoscopy, those who wait 11 years rather than 10 years between regular screening colonoscopies, those who are uninsured, and those who don’t undergo colonoscopy because it is pointless if they are dying of some other disease. The current estimate of the actual numbers in the United States are 14 million screening colonoscopies and 3 million screening flexible sigmoidoscopes.

Medicare alone currently spends $1.8 billion per year on outpatient colonoscopies ($416 million just on professional fees). However, since the majority of screening colonoscopies would be done in patients under age 65 (and thus not covered by Medicare), private insurance companies in the United States pay even more than this.

Are We Meeting All Of The Country’s Needs For Screening Colonoscopy?

If all that a gastroenterologist did was screening colonoscopy, then the demands could be easily covered. However, gastroenterologists (and general surgeons) do far more than just screening colonoscopy. They do endoscopy and colonoscopy for purposes other than screening for colon cancer, they do consults, and they do longitudinal management of patients with gastrointestinal diseases.

The economic law of supply and demand predicts that gastroenterologists will migrate to where screening colonoscopy is highly lucrative. A diagnostic colonoscopy is worth 3.26 work RVUs which equates to about $114 for Medicare. Medicaid will pay considerably less, about $70. The Congressional Budget Office estimates that the average commercial insurance plan pays about 1.75 times more than Medicare for colonoscopy, or about $200 for the physician work component. So, in suburban areas serving patients with commercial insurance, there should be plenty of gastroenterologists to cover the demand for screening colonoscopy whereas in an urban area serving patients with Medicaid, there will likely be insufficient gastroenterologists to cover the demands. The same will be true for rural areas and Veterans Hospitals. So, even if we have enough gastroenterologists (and general surgeons) to meet the overall screening colonoscopy needs in the United States, there will inevitably be geographic pockets of unmet needs that will not be supplied by gastroenterologists (and general surgeons).

Can These Areas Of Unmet Colon Cancer Screening Needs Be Met By Non-Gastroenterologists (And General Surgeons)?

The 2018 Medscape Physician Compensation Report indicates that the average gastroenterologist makes $408,000 per year and the average general surgeon makes $322,000 per year. In comparison, the average physician assistant makes $105,000, the average nurse practitioner makes $107,000 per year and the average nurse anesthetists makes about $169,000 per year. There is not enough data to know what the salary of an NP/PA colonoscopist would make but it is probably in between the average NP/PA and a nurse anesthetists, say about $135,000 per year. Therefore, combining the compensation for the professional services portion of a diagnostic colonoscopy with the average salaries we can determine the number of diagnostic colonoscopies it would take to cover salary (benefits not included).

The next part of this question is whether or not non-physicians can competently perform screening colonoscopy. A meta-analysis from 2014 that pooled results of 24 studies found that polyp detection rates, colon cancer diagnosis rates, and complication rates were similar between nurse practitioner/physician assistants and physicians.

How Many Colonoscopies During Training Are Needed To Achieve Proficiency?

The current recommendations for gastroenterologist training is to do a minimum of 275 supervised colonoscopies. However, one study in 2010 suggested that optimal competency requires 500 supervised colonoscopies; a more recent study in 2016 confirmed the 500 procedure per trainee number. Other studies found competency could be reached after 250 or 275 procedures. The problem with many of these studies is the they did not separate purely screening colonoscopy from colonoscopy with interventions (such as polypectomy). Different professional societies have different recommendations for the number of procedures performed under supervision in order to get hospital privileges.

  1. American Academy of Family Physicians: 50 colonoscopies
  2. American Board of Surgery: 50 colonoscopies
  3. American Society for Gastrointestinal Endoscopy: 275 colonoscopies

So, should your hospital train and utilize physician assistants and nurse practitioners to do colonoscopy?

The answer is probably no if:

  1. The hospital is in a location dominated by patients covered by commercial health insurance
  2. There is currently enough credentialed physicians to meet colonoscopy demand in a timely fashion
  3. There is not a wait time for non-procedural services by the gastroenterologists (outpatient consults, etc.)
  4. There is not an unmet need for surgical services by general surgeons

The answer may be yes if:

  1. The hospital largely cares for a large number of Medicaid and Medicare patients
  2. It is a Veterans Administration hospital
  3. There is a long wait time for screening colonoscopy
  4. There is a long wait time for gastroenterologist consultation because the gastroenterologists are spending too much time in the endoscopy suite
  5. Patients cannot get their hernias repaired and their gall bladders removed because the general surgeons are spending too much time in the endoscopy suite.

What Would I Do If I Was Making Up The Rules?

First, a minimum number of supervised colonoscopies during training would need to be established. Using the ASGE recommendations, this would likely be 275. To win over skeptics, it may need to be as many as 500. A training program for physician assistants or nurse practitioners would be costly because of the additional time required by the gastroenterologist (or general surgeon) to supervise a trainee doing a procedure versus the shorter time it would take himself or herself to do the procedure. Furthermore, it is unlikely that many NPs or PAs would do this time of training for free so there would be the cost of paying their salary during the training period. It would likely take about 3-4 months of fairly intensive, full-time procedural training to achieve the minimum of 275 screening colonoscopies. Once you factor in didactic teaching, non-procedural disease management, and training in other procedures (such as paracentesis), then the entire training program would probably be about a year.

Second, a decision would need to be made about whether the NP or PA will be permitted to do polypectomy unsupervised. If the answer is no, then there would need to be a gastroenterologist (or general surgeon) immediately available in the endoscopy suite who could step in to perform or supervise polypectomy. The only way to make this financially viable would be to have one physician available to two or three NPs or PAs simultaneously.

Third, there would have to be up-front negotiation with payers about reimbursement for screening colonoscopies performed by NPs or PAs. For example, if there is a physician present in the endoscopy suite, can the colonoscopy be billed as “incident to” service or would it be reimbursed as an NP/PA independent service (which generally pays 15% less)?

Fourth, there will need to be a decision made about upper endoscopy. For example, should an NP/PA be able to do routine screening upper endoscopy for patients with Barrett’s esophagus?

What Would My Ideal Program Look Like?

  1. I would start off by having 3 trained NPs or PAs doing screening colonoscopies with a gastroenterologist (or general surgeon) present in the endoscopy suite for polypectomies, complication management, or diagnostic questions. Statistically, at any given time, 1 of the 3 NP/PAs will be doing a colonoscopy that will require the physician’s presence.
  2. I would create a monitoring office where the video feeds from all 3 individual procedure rooms could be fed into monitors so that the supervising physician could periodically check the progress and findings of the procedures.
  3. The NP/PAs would also be trained and credentialed in paracentesis so that they could also be doing those time-intensive paracenteses that gastroenterologists do not want to do.
  4. I would create a hospital-paid position of “Director of Endoscopy Training” to provide financial support for the time a gastroenterologist (or general surgeon) spends supervising the 275 screening colonoscopies that the NP/PA in training requires.
  5. I would make it financially lucrative for the gastroenterologist (or general surgeon) to supervise the 3 NP/PAs by splitting the work RVUs with the physician in a way that makes supervising screening colonoscopy more attractive than performing it solo themself.
  6. During the time that the NP/PAs are not doing colonoscopy, I would have them follow up biopsy results, arrange patient follow-up, complete procedure notes, see inpatient consult follow-ups and, see outpatient return office visits.
  7. I would create a peer-review process whereby the recorded videos of the colonoscopy withdrawal by the NP/PA would be reviewed by another of the NP/PAs so that each NP/PA would have 25 procedures reviewed per year for quality purposes.
  8. Eventually, I would create a pathway for the NP/PAs to be able to perform polypectomies independently. Because I would anticipate a considerable amount of skepticism about a non-physician colonoscopy program, I would phase in polypectomy a few years after the initial screening colonoscopy program with the requirement that the NP/PAs perform some minimal number of supervised polypectomies (for example, 150).

Probably the biggest barrier will be the professional threat that gastroenterologists may feel to having a non-physician do colonoscopy. For most gastroenterologists, colonoscopy is an integral part of their core identity as a specialist. They take pride in their art and skill of colonoscopy and take pride in the number of lives they save by colon cancers prevented. However, medicine is increasingly requiring a team approach and it may be time for us to consider screening colonoscopy as a team sport rather than as an individual sport.

May 4, 2019

Categories
Procedure Areas

Interpreting The Cardiopulmonary Exercise Test

No test in pulmonary medicine is fraught with more confusion and mystery than the cardiopulmonary exercise test, or CPET. This is a test that reports a large number of physiologic measurements during exercise when the patient is asked to exercise to his or her maximum effort. On the one hand, there is a wealth of information in all of those numbers but on the other hand, most physicians don’t know what to do with all of those numbers. As a consequence, the CPET is one of the most under-utilized tests in the hospital. There are several very detailed guides to CPET interpretation, such as the ATS/ACCP Statement on CardiopulmonaryExercise Testing, but these have so much detail that they can be difficult to approach by the average physician. In this post, I will go over a very basic approach to CPET interpretation, albeit one that is fairly oversimplified. I will then cover a second, slightly more advanced approach to CPET interpretation.

Physicians of different specialties use the CPET for different purposes and look at different physiologic measures. I am going to focus on the use of the CPET from the pulmonologist’s vantage point. Although there are many reasons for ordering a CPET, the most common reasons are (1) to determine the cause of a patient’s dyspnea, (2) to determine if a patient can tolerate surgery or lung resection, and (3) to determine whether a patient is disabled.

The test is done by having the patient ride a stationary bicycle (although a treadmill can also be used). The resistance on the bicycle is gradually increased making it harder and harder to pedal and the patient exercises until they can’t go any longer. The patient breathes through a mouthpiece and has a number of monitoring devices that measure:

  1. Heart rate
  2. EKG
  3. Blood pressure
  4. Oxygen saturation
  5. Respiratory rate
  6. Minute ventilation (amount of air that the patient breathes in a minute)
  7. Exhaled carbon dioxide concentration
  8. Inhaled and exhaled oxygen concentration

From these different measurements, a computer is able to calculate a large number of physiologic variables and can generate a large number of physiologic graphs. This is where the CPET report can get overwhelming for many physicians in that there are so many numbers and graphs that it can seem like you are drowning in data. But there is good news… you can ignore most of the data and still get the information that you need from the CPET most of the time. Here are two ways to approach the CPET, a basic interpretation approach and an advanced interpretation approach.

The Basic Approach

This will answer the questions “Is the exercise impaired?” and “If so, is impairment due to heart disease or lung disease?”.

  1. Look at the mVO2 (maximum oxygen uptake). If it is reduced, then there was abnormal impairment to exercise. If it is normal, then the patient can exercise normally and is not impaired; most of the time, this means that you can stop here.
  2. Look at the reason for stopping exercise. Most of time, patients will stop because of leg fatigue or shortness of breath. However, if the patient has chest pain, it may be a clue to myocardial ischemia. If the patient had calf pain, it may be a clue that they are limited by claudication. If they fell off the bike or couldn’t keep the mouthpiece in place, then the test is invalid.
  3. Look at the heart rate. If the patient reached a maximum predicted heart rate, then exercise was limited by the cardiovascular system. A normal predicted heart rate = (220 – age). Anything > 90% of maximum is considered abnormal. Note: normal people are limited by their cardiovascular system so if the mVO2 is normal (indicating no exercise impairment), then the patient should reach a maximum predicted heart rate. If the patient is taking a beta blocker, they will not reach a maximum heart rate and so the heart rate analysis will be indeterminate.
  4. Look at the mVE (maximum minute ventilation). A normal person should have an mVE that is < 75% of predicted, in other words, a normal person’s exercise is never limited by their lungs. Another way of saying this is that we are all born with 25% more lung than we actually need. The predicted maximum minute ventilation can either be calculated by the equation [FEV1 x 40] or by having the patient breath as rapidly as possible while sitting at rest for 30 seconds then multiplying the result x 2 (this is called the maximum voluntary ventilation or MVV). The difference between the predicted maximum minute ventilation and the actual maximum minute ventilation during the CPET is the “ventilatory reserve”. If the mVE is > 85% of predicted (i.e., the ventilatory reserve is < 15%), then the patient is abnormally limited by pulmonary disease.
  5. Look at the oxygen saturation. A significant drop is > 4%. The oxygen saturation does not drop when a normal person exercises. If the oxygen saturation falls, then there is likely pulmonary disease.
  6. Look at the blood pressure. Normally, the systolic pressure goes up during exercise but the diastolic pressure stays the same. If the diastolic pressure rises, then hypertension could be the cause of the patient’s limitation. Normally, at peak exercise the blood pressure should be < 220/90.
  7. Look at the EKG. If there are ischemic changes, then heart disease may be the cause of exercise limitation.

Using the basic approach will usually allow you to stratify patients into 4 categories of exercise limitation: (1) normal, (2) cardiac, (3) pulmonary, or (4) non-cardiac, non-pulmonary.

 

This table is not perfect. For example, many patients with heart disease may reach a maximum predicted heart rate but have a normal diastolic blood pressure and no ischemic changes on the EKG. Similarly, some patients with lung disease may have a maximum minute ventilation > 85% of predicted but do not desaturate. In other words, patients with abnormal cardiovascular or pulmonary limitation do not need to have all of abnormalities listed above, just one of them. Also, the category of “non-cardiac, non-pulmonary” is very broad and can include patients who gave a poor effort on the test, patients with neuromuscular disease, patients with peripheral vascular disease, those who are deconditioned, and those who are obese.

If you are ordering the CPET to determine if a patient is able to undergo lung resection surgery, you can just focus on the maximum oxygen uptake (mVO2). Those patients with a relatively preserved mVO2 can generally undergo lung resection safely. This can be a particular help in those patients with lung cancer and a low FEV1 who might appear to be high risk based on spirometry. However, the cardinal rule of lung cancer treatment is to never miss an opportunity to send a surgically curable patient to a surgeon, so the CPET can sometimes give you the confidence you need to proceed with surgical resection.

If you are ordering the CPET to determine disability, then there are gradations of disability that are used in the AMA’s Guides To The Evaluation Of Impairment that are often accepted by disability granting agencies. Disability can be stratified by disability class or by the percentage of the whole person that is impaired based on the mVO2.

The Advanced Approach

If the basic approach is “CPET 101” (freshman level CPET interpretation), then the advanced approach is “CPET 201” (sophomore level CPET interpretation). There is an even higher level approach to CPET interpretation (“CPET 401”) that is covered by the ATS/ACCP Statement on CardiopulmonaryExercise Testing. The advanced approach relies on analysis of the anaerobic threshold and analysis of the physiologic graphics generated by the CPET.

The anaerobic threshold occurs when a person’s muscles switch from aerobic metabolism to anaerobic metabolism. When this happens, the muscles are not consuming oxygen to produce energy and the muscles start to produce lactic acid. The body keeps producing carbon dioxide so the VCO2 keeps going up, but the body doesn’t take up greater amounts of oxygen so the VO2 stops rising as quickly. The body can only sustain anaerobic metabolism for a short time, however. When the muscles shift into anaerobic metabolism, a number of things happen:

  1. The blood lactate level rises. However, serial lactate testing is usually not used in a CPET since it would require blood draws every 30-60 seconds.
  2. The production of carbon dioxide rises disproportionate to the consumption of oxygen. This can result in the VCO2 (carbon dioxide production) rising faster than the VO2 (oxygen consumption). In this graph, The VCO2 is plotted on the vertical axis and the VO2 is plotted on the horizontal axis. In normal aerobic metabolism, the relationship between the VCO2 and VO2 should be a straight line. Once the exercising patient shifts into anaerobic metabolism, the VCO2 starts to go up faster than then VO2. This is shown in the graph where the blue dots (that represent individual measurements) start to rise rapidly. This defines the anaerobic threshold, shown by the green line. This is sometimes called “a change in the V-slope”. The change in VCO2 compared to the VO2 can also be seen in this graph of the VO2 and VCO2 plotted against the total work performed. In this case, the VCO2 (blue dots) begins to rise faster than the VO2 (red dots) when the patient switches into anaerobic metabolism result in the two curves crossing at 75 watts of work.
  3. The respiratory quotient starts to increase. A normal respiratory quotient (RQ) in a person who is burning up carbohydrates during metabolism is 1.0. If they are metabolizing fat, the RQ is 0.7 and if they are metabolizing protein, the RQ is 0.8. When carbon dioxide is derived from lactic acid, the RQ goes up to a level above 1.0. In this graph, you can see the rise of the RQ (green dots) above the RQ of 1.0 (red dashed line) – this sudden increase in the RQ indicates that the exercising patient just crossed the anaerobic threshold. Sometimes, the RQ (respiratory quotient) will be reported as the RER (respiratory exchange ratio) in a CPET report.
  4. The end-tidal oxygen concentration (PETO2) begins to rise. When the muscles switch to anaerobic metabolism, they are no longer primarily consuming oxygen to make energy. Consequently, the lungs extract less oxygen out of the inhaled air. This results in the oxygen in the exhaled air (the PETO2) to start to go up. In this graph, the PETO2 was fairly stable at about 110 mm Hg during aerobic metabolism but when the muscles switched to anaerobic metabolism, the PETO2 began to rise (yellow arrow) at the 10 minute mark of the CPET.
  5. The ratio of minute ventilation to oxygen uptake begins to rise. During normal aerobic exercise, this ratio is fairly consistent but when the muscles switch to anaerobic metabolism, there is less oxygen being taken up by the lungs (as we saw with the rise in the PETO2 in the previous paragraph). This results in a change in the ratio of the minute ventilation to the oxygen uptake (VE/VO2) so that as the VO2 goes down in anaerobic metabolism (in the denominator of the VE/VO2 equation), the ratio VE/VO2 goes up. This is shown by the rise in the red dots marked by the yellow arrow at the 13 minute mark of this CPET. In this case, the VE/VCO2 also goes up after anaerobic threshold but to a lesser degree (blue dots).

In the best of possible worlds, all of these markers of anaerobic threshold should happen at the same time. Unfortunately, the anaerobic threshold is not always easy to determine. The graphs never seem to work out like the examples that are usually shown in textbooks. There can be leaks in the mouthpieces and other causes of subtle errors in measurements. Furthermore, anaerobic threshold is not just an all-or-none event for all of the muscles in the body at exactly the same time – some muscle groups go into anaerobic metabolism sooner than others so the anaerobic threshold that we seen on the CPET is really an average of lots of muscle groups all going into anaerobic metabolism at different times. A normal person should reach anaerobic threshold at about 50-60% of their mVO2; if the patient reaches anaerobic threshold at < 40% of the predicted mVO2 then the anaerobic threshold is considered reduced.

Another variable that can be useful is the dead space determination. Normally, to calculate the dead space, arterial blood gases are necessary but these are generally not done during most CPETs. You can get a rough estimate of the dead space during exercise by looking at the VE/VCO2 at anaerobic threshold. A value greater than 34 indicates an abnormally increased dead space. This can be caused by lung diseases, pulmonary hypertension, or heart failure. If the dead space goes up extremely high during exercise, think about pulmonary hypertension.

By first determining if the patient actually exercised to the point of anaerobic metabolism and then determining the anaerobic threshold, you can do a deeper analysis of the CPET for the advanced approach:

  1. Look at the mVO2 (maximum oxygen uptake). If it is < 85% of predicted, then there was abnormal impairment to exercise. Most CEPT reports will give the predicted mVO2 based on the patient’s actual body weight. However, if the patient is obese, then it is very helpful to also calculate the predicted mVO2 based on the patient’s ideal body weight. This correction can help you determine if a patient’s low mVO2 is just due to their obesity.
  2. Determine if there was respiratory limitation. To assess this, you will need to look at the mVE, the dead space, and the oxygen saturation. There are 3 abnormalities that can indicate abnormal respiratory limitation:
    1. mVE > 85% of the MVV (or > 85% of [FEV1 x 40])
    2. Increased dead space as defined as an increased VE/VCO2 of > 34 at anaerobic threshold (or > 40 at peak mVO2)
    3. Oxygen desaturation of > 4% from baseline.
  3. Determine if there was cardiovascular limitation. There are 3 abnormalities that can indicate abnormal cardiovascular limitation:
    1. The mVO2 is low and the patient reaches > 90% of the maximum predicted heart rate (220 – age)
    2. There are ischemic changes on the EKG
    3. There is an abnormal blood pressure response. The could either be drop in the systolic pressure with exercise or an abnormal rise in diastolic blood pressure (>90 mm Hg) with exercise
  4. Determine if the anaerobic threshold was reduced. There are many diseases that can cause a reduced anaerobic threshold (defined as an anaerobic threshold occurring at < 40% of the predicted mVO2) and so if there is an isolated reduction in the anaerobic threshold, you will need to search for the cause. Some of the more common causes are:
    1. Hypoxemia during exercise (from lung disease)
    2. Pulmonary vascular disease
    3. Liver failure
    4. Renal failure
    5. Cardiac disease (including ischemia, heart failure, valvular disease, and conduction disease)
    6. Anemia
    7. Peripheral vascular disease
    8. Neuromuscular disease

Using this analysis, the results can point toward several conditions:

 

Here is an example of a patient with combined diastolic heart failure, secondary pulmonary hypertension, coronary artery disease, plus interstitial lung disease. The clinical question was which of his diseases was responsible for his shortness of breath? The anaerobic threshold was determined to occur at 10.09 minutes (best seen on Plot 6 of the graphs). First, look at the mVO2 – in his case, it was reduced at 12.4 ml/kg/min (67% of predicted), so exercise was abnormally impaired. Second, determine if he had an adequate ventilatory reserve – he did not since his mVE was 73.8 L (98% of predicted) – this indicates lung disease as a cause of his exercise limitation. Third, determine if he desaturated – he did not since his saturation at peak exercise was 97%. Fourth, determine if he had an excessive dead space – he did since his VE/VCO2 at anaerobic threshold was 36 (anything over 34 being abnormal) – this is further evidence of lung disease. Fifth, determine if he reached his maximum predicted heart rate – he did not since his heart rate at peak exercise was 93 (62% of normal) indicating that it was not his cardiovascular system that limited his exercise. Sixth, determine if the anaerobic threshold is reduced – his anaerobic threshold occurred at a VO2 of 6.4 ml/kg/min which is a VO2 of 34% of his predicted mVO2 (6.4 ÷ 18.5) and therefore reduced since it is less than the normal threshold of 40% of the predicted mVO2. Seventh, determine whether the blood pressure response is normal – his systolic blood pressure rises normally to 160 but his diastolic blood pressure also rises from 60 to 78, which is abnormal – this probably is related to his diastolic heart failure but since the diastolic blood pressure remained < 90 mm Hg, it was probably not the primary limit to exercise. From the exercise test, we can determine that it is his lungs (in his case, the interstitial lung disease), not his heart that is the cause of his impairment.

As with many tests in medicine, the results are best interpreted in the context of the individual patient. Therefore, the physician who is familiar with the patient’s history and has done a physical examination is in the best position to accurately interpret the CPET. But for those patients who have shortness of breath and you are unsure if it is due to undiagnosed heart disease, undiagnosed lung disease, obesity, or deconditioning, the CPET can often be tremendously helpful. Also, in those patients who have both known heart disease AND known lung disease, the CPET can help determine which of the two diseases are the cause of shortness of breath and exercise limitation.

January 8, 2018

 

 

Categories
Procedure Areas

Endoscopy Unit Efficiently

One thing we can all agree on is that identifying cancers by screening at an early, treatable stage saves lives. I’m going to make the argument that the most expensive cancer screening test is the colonoscopy if your endoscopy unit is not run efficiently. Other cancer screening tests are quick to perform and don’t require a lot of hospital resources – a patient can leave work to get a PSA, Pap smear, chest CT, or mammogram and be back at work an hour or two later. These screening tests don’t require sedation and they don’t require any special preparation. Colon cancer screening with colonoscopy is totally different:

  1. The patient has to take an entire day off work
  2. Because they receive sedation, the patient has to have an adult driver to take them home and stay with them for a few hours and that person needs to take the day off of work
  3. The patient requires a prep that adds a small additional cost but is often disliked
  4. If the prep is not adequate, then the patient has to take another day off work to come back for a repeat procedure
  5. The procedure takes somewhat more time than other cancer screening tests (30 minutes in a procedure room and additional time in a post procedure room)
  6. A physician and 1-2 assistants have to be scheduled to be in the procedure room for that 30 minutes and a recovery nurse has to be scheduled for 30-45 minutes to care for the patient

Therefore, it is essential that the colonoscopy process and the endoscopy unit have maximal operational efficiency. The goals are to have every patient show up, have every colon prep be excellent, and have a process to move patients through the endoscopy unit smoothly. If patients have poor preps and have to take an additional day from work to have a second procedure, then the indirect costs of lost work hours and cost to the employer can result in the making this a very expensive screening test. You also want to avoid having the physician or the nursing staff standing around doing nothing if the patient does not show up for a scheduled procedure. So here are some of the considerations:

The colon prep

As a general rule, patients will dislike the prep more than they dislike the procedure. There are several preps that can be used, the most common are the GoLYTELY prep and the Miralax/Dulcolax prep. 

  1. GoLYTELY. This is a solution of polyethylene glycol. The patient drinks about a gallon of it and it goes through the GI tract without being absorbed so it flushes anything in the intestines out. Many gastroenterologists believe that this prep gives the best results by leaving the colon free of any stool or undigested food. However, patients generally do not like the large volume required to be consumed. This can be partially overcome by doing a “split prep” when the patient drinks 2 liters of GoLYTELY the night before the colonoscopy and 2 liters early in the morning of the colonoscopy. The other downside of GoLYTELY is that it has to be prescribed by a doctor – this can often be a challenge because sometimes, the primary care physician is uncomfortable ordering preps for procedures if they are unfamiliar with the preps and the gastroenterologist or surgeon doing the colonoscopy is usually seeing the patient for the first time when he/she is wheeled into the procedure room and they often don’t want to prescribe something for a patient before they ever see them. GoLYTELY is FDA-approved as a colonoscopy prep
  2. Miralax/Dulcolax. Both of these are available over the counter. The patient takes the Dulcolax tablets the day before the colonoscopy and then mixes the Miralax in 2 quarts of Gatorade and drinks it. The total volume is half that of GoLYTELY, which makes this a preferred prep by many patients. But some gastroenterologists believe that it does not clean out the colon as well as GoLYTELY. Because Miralax and Dulcolax are available over the counter, there is no controversy about which physician will prescribe the prep. This is not an FDA-approved indication for these medications. There are rare reports of ischemic colitis developing with this prep.

The bottom line: Because a poor prep (requiring a repeat procedure) is very costly to the patient and the patient’s employer, it is critical that you give a patient a prep that they can take and that works. Split-dose preps are better in most situations and the lower volume of the Miralax/Dulcolax prep may give it an advantage over GoLYTELY for many patients.

Scheduling the colonoscopy

For patients who don’t work or who are retired, getting their procedure done on a weekday morning is often preferred. That way, they don’t have to be NPO or restricted to nothing but clear liquids for excessively long. Some patients can’t afford to take a day off of work and for them, having Saturday colonoscopy schedules may be preferred. Other patients may prefer an afternoon or evening colonoscopy so that they (or their driver) only has to take part of a day off work. So, you need to survey your patient population and cater to their preferred time. Moreover, an endoscopy unit is an expensive investment for the hospital and you want to be sure that you use it to capacity. Consider opening the endoscopy suite one Saturday a month and doing both morning and afternoon weekday schedules.

The navigator

As you can see, it is critical that the patient does the prep right. And although a colon prep seems like an uncomplicated thing, there is a lot that can go wrong. This is where the “navigator” comes in. They are kind of like colonoscopy coaches – they call the patients several days before the prep to be sure that the get the right medications/supplies and know what to expect. They call the patient the day of the prep to be sure that they are doing it correctly and that they have a driver arranged. The patient can call them if they have any questions. The navigator doesn’t have to be a nurse – it can often be someone with considerably less education but who communicates well and has common sense. Studies have shown that by using a navigator, the no-show rate and the poor-prep rate improve considerably. This is particularly true if your patient population is older, lower income, or has lower healthcare literacy.

Identifying patients at high risk for sedation

Not all patients can safely undergo moderate sedation administered by the physician performing the colonoscopy. These high-risk patients need sedation administered by an anesthesiologist who can devote total attention to keeping the patient safe during sedation. Patients who are sometimes better suited to have an anesthesiologist include those with sleep apnea, those with significant heart or lung disease, those who have been difficult to sedate in the past, etc. You need to develop a mechanism to identify these patients before they show up in the endoscopy unit for their procedure so that you can schedule them at a time and location where there is an anesthesiologist available. Since the physician performing the colonoscopy does not see the patient before the hour of the procedure, there has to be some way to catch these patients so that you don’t have to turn them away and reschedule them on another day. Options can include having scripted questions that your schedulers or the navigator ask the patient, having a nurse review the patient’s information in the electronic medical record the week prior to the procedure, or asking the primary care physicians to request the procedure to be done with or without an anesthesiologist. The latter option generally does not work because the primary care physician is generally uncomfortable making a decision about the type of sedation or anesthesia since they are not trained in doing so. Having a nurse review the EMR may work when all of the primary care physicians in your community are using the same EMR that you do but in most communities, this is not the case.

Room turnover time

Just like operating room turnover times are a metric of OR efficiency, endoscopy procedure room turnover times are an important metric of endoscopy unit efficiency. The first step is to develop a way to measure it regularly. Then figure out what slows it down. If you have one person who cleans the room between procedures and you have 3 procedure rooms, then consider staggering the scheduled start times for each procedure room so that when the room cleaner finishes with one room, the next room is ready to be cleaned and prepared. Sometimes, it is cleaning the equipment rather than cleaning the room that increases the length of time between procedures. If this is the case, then you may need an additional scope washer or just plain more scopes. You need a minimum of 2 colonoscopes and 2 upper scopes per procedure room.

Sedation time

The quicker the patient is sedated, the shorter the time that the physician and endoscopy staff have to wait in the procedure room to start the procedure. Also, the faster a patient wakes up after their procedure, the faster he/she can be discharged and  thus free up a pre/post procedure room and nurse. Fentanyl and Versed are a commonly used sedative combination but typically, you have to wait 3 minutes between re-dosing patients. If a patient unexpectedly turns out to require a lot of fentanyl and Versed to get adequately sedated, it may be 9 or 12 minutes before the procedure can start. Some endoscopy units have gone to using propofol for sedation because of its rapid onset and rapid recovery; however, in Ohio, nurses are not able to administer propofol for procedural sedation so you have to have a second physician (usually an anesthesiologist) on hand. If your physicians are using longer onset of action drugs like lorazepam and Demerol, then the sedation times will increase.

Physician charting time

The physician may do 16 or more procedures during a full day and you want that physician spending as much time in the procedure room doing procedures as possible. Therefore, you want to have a process for them to chart their pre-procedure assessment and their post-procedure note as rapidly as possible. If you require them to spend 15 minutes hand-writing their notes, then the physician will not be able to do as many procedures in a day. We use Provation for our documentation and it works pretty well. Try to get the charting time down to < 3 minutes.

Adenoma detection rate

If you focus too much on pushing your doctors and staff to do procedures faster, then they may not be doing as thorough of colonoscopies. One way to measure this is the adenoma detection rate. If your doctors find adenomas in relatively few patients, then they are probably missing some. You have to be a little careful because the incidence of adenomas can vary depending on the different patient demographics. For example, the incidence of adenomas in men is higher than in woman and the incidence is different in older patients than in younger patients. Also, the incidence of adenomas is higher in surveillance colonoscopies than in screening colonoscopies. Therefore, a lower adenoma detection rate does not necessarily mean that one doctor is sloppier than another – he or she may just have a different patient demographic. As a general guide, adenomas should be found during screening colonoscopies in 15% of women and 25% of men. Therefore, if your doctors are consistently finding adenomas in only 10% of their screening colonoscopies, then you have a problem.

This can all seem pretty overwhelming for a medical director who is not a gastroenterologist. So, here is my recommendations on where to start with collecting efficiency metrics from your endoscopy unit:

  1. Cancelation rate
  2. No-show rate
  3. Poor prep rate
  4. Number of procedures per room per day
  5. Room turnover time
  6. Adenoma detection rate

Develop a mechanism for regular reporting of these metrics. Once you get comfortable with these basic metrics, then you can drill down on other metrics to fine-tune your operational efficiency. If you have an efficient endoscopy unit, then colon cancer screening is no long the most expensive cancer screening test.

July 1, 2017

Categories
Inpatient Practice Procedure Areas

Optimizing Hospital Inventory: Sometimes Something So Simple…

Ever have one of those moments when someone presents a new idea and you think, “That just makes way too much sense”? This week, I listened to a presentation by one of our health system’s supply chain directors who presented a new way of managing terminal distribution supplies.

If you have worked for more than about a week in a hospital as a physician or a nurse, then you have had the experience of walking into a supply room on a nursing unit and seeing something like this. Bins of supplies stacked on top of each other and overflowing with syringes, gauze pads, and telemetry leads. Its a mess. If you can even find the bin you are looking for, there is a good chance the person before you took the last one of the items that you wanted. And when you have a JCAHO site survey, the surveyors always head straight to the supply room when they walk into a nursing unit and then dig their hand into the most full bin and pull an item from the bottom of the bin… and the date on it will inevitably be expired, resulting in a citation. Supply rooms were like the first day I walked into the hospital as a 3rd year medical student in 1982 and supply rooms are like that now, 35 years later, in 2017.

So, here was the solution from our supply chain genius. Instead of having one large bin for each item, have 2 small bins, one in the front and one in the back. You stock each bin with a projected 5-days worth of that item. Each bin is bar-coded for inventory management. This is known as a “Kanban” inventory control system

When you use up all of the item in the front bin, you pull the empty bin and leave it out for your central supply personnel to pick up. You then pull the back bin forward and start to use items from it. The central supply staff re-stock the empty bin and replace it behind the front bin. Here’s what happens:

  1. Your central supply personnel know exactly how fast you are going through each item so that your nurses don’t need to ‘guesstimate’. By using the bar code on each bin, you can monitor item use on the computer real-time.
  2. You can adjust the number of each item at your terminal distribution supply room based on use, thus optimizing your space utilization.
  3. The supply room becomes less cluttered.
  4. The square foot requirement in the supply room actually drops.
  5. You dramatically reduce the risk of having expired items in your supply room.
  6. You eliminate all of the time that the nurses are “taking inventory” of everything in the supply room and give them back time to do patient care.
  7. You save money

There are some caveats, however. The nurses have to be trained so that they always remove items from the front bin and know to pull the empty bins out for re-stocking. If your patient population on any given nursing unit changes, then your product use rate can change, so you have to continually monitor how quickly you are going through bins in each supply room.

This is one of those ideas that when you hear it, you ask yourself, “So, why didn’t I think of this before?”.

March 31, 2017

Categories
Procedure Areas

The Dialysis Blues

dialysisEnd-stage renal disease has been driving me crazy recently. When no one else will dialyze you, the hospital has to. There’s this thing called EMTALA law that requires us to treat you if you show up in our emergency department. Let me tell you about a few of our more exasperating patients that could fill out the entire cast in a theater of the absurd. In order to prevent being presented with a subpoena from the HIPAA police for violating patient confidentiality, I’ve made a few changes to the details, but not too many.

First case is a lady who decided that what she really wanted from Santa for Christmas was a new Glock handgun. The perfect fashion accessory for the woman who has everything. She was really proud of it so she showed it off to all of her friends at her dialysis center. The problem is that the dialysis center had a zero tolerance policy for patients bringing in hand grenades, surface-to-air missiles, nuclear bombs, and other weapons into the dialysis center. So she was banned for life from returning. Because she still needed dialysis that day, she came to the emergency department and got admitted. And we dialyzed her. And for a hospital, once you dialyze a patient, you own them forever. So it became our problem to arrange for regular 3-times a week outpatient dialysis. But the word got out and none of the other dialysis centers in town would take her. So, we were stuck with doing her dialysis. But the problem is, we are certified as an inpatient dialysis unit and not as an outpatient dialysis unit. Therefore, her insurance company said that the only way they would pay us to dialyze her was if she was an inpatient.  So, rather than having her just show up 3 days a week in the dialysis unit, get dialyzed , and go home, we had to admit her. The problem is that the insurance company wouldn’t pay for an elective hospitalization for renal failure, only an emergency hospitalization for renal failure. The only way we could get paid was to have the patient come into the ER, be seen by the ER physician, get labs to prove that her potassium was too high and her bicarbonate was too low, get admitted to the hospital, have a resident do an H&P and admission orders, get a nephrology consult, get dialyzed, and then have the admitting service do a discharge summary. Fortunately, after a couple of months, one of the private dialysis centers came through and accepted her… but only after we had proven that she wasn’t packing a gun any more by going through the metal detector in the emergency room every Monday, Wednesday, and Thursday for 8 weeks.

Second case is a guy from Nicaragua who decided to come visit his son in the United States. The only problem was, he didn’t have a passport. And his kidneys didn’t work. So, he jumped the fence in Texas and hitched a ride to Central Ohio. A couple of months later, he ended up in our emergency room with uncontrolled hypertension and kidney failure. We dialyzed him… and then we owned him. He got a dialysis access fistula but since he was an undocumented foreign national (the politically correct term for illegal immigrant) with no health insurance, no dialysis center would take him. And so now he comes into the ER every Tuesday and Friday and gets dialyzed. He needs medications for his blood pressure and his other medical problems but he can’t afford to buy them so he doesn’t take them. It turns out that this is not such an infrequent occurrence. What one of the private hospitals in Columbus does is when they get a patient like this, they don’t want to have to mess with doing the dialysis so the hospital actually pays a private dialysis center to do the dialysis. A hospital in Chicago tried to deal with a similar situation by arranging for their patient to be deported but there was such a public opinion outcry that they backed off. Since we are a State hospital, we can’t pay for a private dialysis center to do dialysis on an undocumented foreign national (lest it be perceived we are using taxpayer dollars to pay someone to dialyze an illegal immigrant) and we don’t want to risk the public relations nightmare of deporting someone’s poor grandfather because we won’t treat his medical problems.

The third patient got off of a plane at John Glenn International Airport after a long flight from Kenya. She hopped in a cab and came straight to our emergency department because she needed her regular dialysis. It seems that she sort of forgot to check the box on the visa form about having end-stage renal disease and needing dialysis three times a week. She wasn’t going to get back on the plane so we admitted her and dialyzed her… and then we owned her. Fortunately in her case, a local church group raised dialysis money and one of the local private dialysis centers took her on a cash basis.

In these situations, no one wants to pay for the dialysis for these patients. So what happens? We all pay for it. Because even though our hospital covers the cost of dialysis, we do it using the margin that we make from all of the insured patients, Medicare patients, and Medicaid patients that come through our doors. And it is the same for every patient that we take care of who is uninsured. Their care is paid for by everyone who pays payroll taxes and health insurance premiums. So when we dialyze them, American owns them.

November 2, 2016