Blood Gasses Save Lives If You Know What To Look For

To be a great internist you have to be great at blood gas interpretation. And you have to be able to do it quickly and efficiently. You have to understand what all the numbers mean and you have to get a good clinical sense of how to interpret them and how to change management based on their result. And you have to be able to do it without pulling out your formula books. In six years as a hospitalist I have never calculated what the compensatory responses should be. I just know.

Sometimes blood gases change your management or your medical opinion on what’s happening. Take for example my patient with advanced MS. She presented through the emergency department with “oropharyngeal bleeding of unclear etiology”. Her original BMP:

Na 137
K 4.0
CL 99
HCO3 36
BUN 35
CR 1.0

Her medications included baclofen, lasix and and aspirin and that’s about it. When I first saw the data, my first inclination was to attribute the elevated bicarb to chronic hypercapnic respiratory failure with a compensatory metabolic alkalosis. It would make sense. Multiple sclerosis<->failing respiratory drive.

But I had the respiratory folks draw a blood gas anyway. To confirm my suspicions and to clarify the degree of hypercapnea.

Here is what I got

pH 7.47
pCO2 46
pO2 58

And this is why obtaining a blood gas can be important in deciding exactly what is going on. In this case, I was wrong. The patient had hypercapnea but it wasn’t the primary process. As you can see, having an alkalotic pH by definition excludes a primary respiratory acidosis. What we have here is a primary metabolic alkalosis with incomplete compensatory respiratory acidosis.

A close look at the labs show a significant BUN/Cr ratio. While I originally thought this to be secondary to blood passing through the GI tract, in retrospect, it is likely an indication of a significant state of volume depletion secondary to chronic lasix therapy.

I originally planned on providing no saline support. But my mind changed when I saw the alkalotic nature of the blood gas. I initiated IV fluids and discontinued the diuretic therapy and gave it some time.

With the diagnosis made, repeating the blood gas would be an exercise in academia, something us community guys generally avoid.

The first two things I do when I see a patient is

1. Review the vital signs
2. Calculate the anion gap and review the bicarb status to determine if a blood gas is warranted.

I have saved many lives and had significant changes in management due to surprise findings on blood gas evaluations. You can’t really know what’s going on unless you have confidence in your patients acid-base status. To become highly competent in ABG management and the hundreds of clinical situations, often life threatening, that arise, you must be able to make decisions in minutes. You must have a strong grasp of the fundamentals. You must see thousands of them to make it automatic.

The evaluation of acid base situations is a core learning principle for all medical students and something that internists must have a strong foundation in understanding. For me, their evaluation is mostly automatic. Some clinical scenarios are more complicated than others. But knowing your way through acid base will save lives your entire career.

And that is a great feeling to have. And knowing that you don’t know how to interpret them leaves you at a significant disadvantage to providing the right care that patients deserve. If you aren’t highly competent in acid-base, you are not capable of practicing a full scope of primary care medicine. Unless of course you wish to define primary care as something less than it really is.

*This blog post was originally published at A Happy Hospitalist*

Models Of Healthcare In The Developed World

I heard an interview with T.R.Reid and can’t wait to read his book The Healing of America: A Global Quest for Better, Cheaper, and Fairer Health Care. He traveled the world and compared how developed countries manage health care. He makes the point that all other developed countries have universal coverage. No-one is left out.

He found four basic systems (some named after their founders):


The Beveridge Model: Health care is provided and financed by the government through tax payments, just like the police force or the public library. Some clinics, hospitals and doctors are government employees (like the Veterans Administration in the U.S.), and some are private doctors who collect their fees from the government. The government is the sole payer and the patient never, ever gets a bill. Preventive care is exceptional because health care is paid from cradle to grave and keeping the population healthy is a priority of the government. There are no stockholders to pay so health care dollars are used solely on health.

(Great Britain, Spain, most of Scandinavia, New Zealand, Hong Kong, Cuba)

The Bismark Model: It uses an insurance system financed jointly by employers and employees through payroll deduction. There are about 240 different insurance funds in Germany but they have to cover everybody and they don’t make a profit. There is tight regulation so government has much of the cost-control clout that the single-payer Beveridge Model provides. Doctors and hospitals are private and patients can choose any provider they want.

(Germany, France, Belgium, the Netherlands, Japan, Switzerland and some Latin America)

The National Health Insurance Model: This system uses independent providers but payment comes from a government-run insurance program that every citizen pays into. There is no profit, no marketing and no financial motive to deny claims so these insurance programs are cheaper and easier to administer. ( This runs like U.S. Medicare). National Health Insurance plans control costs by limiting the medical services they will pay for.

(Canada, Taiwan, South Korea)

The Out of Pocket Model: In all of the other developed countries everyone is covered. The rest of the world (including 47 million Americans) are too poor and too disorganized to provide health care. If you don’t have the money to see a doctor, you do without and get sicker or die. That’s it…survival of the financial fittest.

The United States is unlike every other country because it maintains many separate systems for different classes of people. We have parts of every model but we are the only developed country that allows investor profits to dictate our health care. We are the only developed country that does not focus on primary care.

*This blog post was originally published at EverythingHealth*

How drinking too much sugary soda pop raises risk of kidney disease in women

Drinking too much soda pop could wear out your kidneys. Read the study, " Sugary Soda Consumption and Albuminuria: Results from the National Health and Nutrition Examination Survey, 1999–2004 ." Drinking sugary soda raises the risk for kidney disease in women. How kidney disease eventually is caused links soda consumption to kidney damage. See the article, " Opposing Views: RESEARCH: Drinking Soda Raises Risk for Kidney Disease ." Women who drink two or more cans of soda pop per d

Quality-Based Medicare Payments: Will They Kill Private Practice?

It’s the holy grail of physician payment reform: ending fee-for-service payments to doctors and, instead, pay doctors based on the quality of care they perform. Remarkably, Congress feels they’ve found the answer:

Thus, the new language in the Senate Finance bill would finally connect Medicare reimbursements to quality, as opposed to volume.

The measure gives the secretary of Health and Human Services, working with the Centers for Medicare and Medicaid Services, the power to develop quality measurements and a payment structure that would be based on quality of care relative to the cost of care. The secretary would have to account for variables that include geographic variations, demographic characteristics of a region, and the baseline health status of a given provider’s Medicare beneficiaries.

The secretary would also be required to account for special conditions of providers in rural and underserved communities.

Additionally, the quality assessments would be done on a group-practice level, as opposed to a statewide level. Thus, the amendment would reward physicians who deliver quality health care even if they are in a relatively low quality region.

The secretary of Health and Human Services would begin to implement the new payment structure in 2015. By 2017, all physician payments would need to be based on quality.

Wow. That sounds great! But there’s just one problem…

… how do we define “quality?”

Medicare has historically withheld payments to physicians unless they performed lock-step “quality measures” before granting release of the remainder of 1.5 percent of the doctors’ payments that were billed. Needless to say, this model has been an abysmal failure (subscription) at improving the “quality” of care delivered and has been very expensive to implement. Further, others have noted the challenge of measuring quality on the basis of clinical outcomes.

But this has not dissuaded our legislators from forcing the “quality issue.” No, they have proposed to find a fix by the creation of a hugely expensive C.M.S. Innovations Center:

“It would be funded with $10 billion over the next several years to implement pilot projects and demonstrations to promote new payment reform opportunities. There are quite a few problems with the bill, but this provision is truly visionary. The House legislation, HR 3200, mentions payment reform, but it [provides] only modest funding of $275 million. That’s not enough.

I suppose $10 billion compared to $275 million is “truly visionary” if you stand to receive the funds. One wonders what the tax payers will get at the end of the day for this grotesque amount of money.

Perhaps I’m too cynical, but I think the subliminal message coming from Washington so far is really this: doctors should be happy becoming salaried employees of larger health systems. This way, the government can pay the health system a bundled fee and the doctors can fight for their share of the kitty.

So far, this seems to be how the government will envision “quality” at an affordable price in the years to come.

I just wonder how many doctors will stick around to find out.

-Wes

*This blog post was originally published at Dr. Wes*

Content Keyword RSS 2009-09-30 08:41:52