My Dominant Hemisphere

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Posts Tagged ‘Medical Mishaps

The Doctor’s Apparent Ineptitude

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ineptitude

via Steve Kay@Flickr (by-nc-nd license)

As a fun project, I’ve decided to frame this post as an abstract.

AIMS/OBJECTIVES:

To elucidate factors influencing perceived incompetence on the part of the doctor by the layman/patient/patient’s caregiver.

MATERIALS & METHODS:

Arm-chair pontification and a little gedankenexperiment based on prior experience with patients as a medical trainee.

RESULTS:

Preliminary analyses indicate widespread suspicions among patients on the ineptitude of doctors no matter what the level of training. This is amply demonstrated in the following figure:

As one can see, perceived ineptitude forms a wide spectrum – from most severe (med student) to least severe (attending). The underlying perceptions of incompetence do not seem to abate at any level however, and eyewitness testimonies include phrases such as ‘all doctors are inept; some more so than others’. At the med student level, exhausted patients find their anxious questions being greeted with a variety of responses ranging from the dumb ‘I don’t know’, to the dumber ‘well, I’m not the attending’, to the dumbest ‘uhh…mmmm..hmmm <eyes glazed over, pupils dilated>’. Escape routes will be meticulously planned in advance both by patients and more importantly by med students to avert catastrophe.

As for more senior medics such as attendings, evasion seems to be just a matter of hiding behind statistics. A gedankenexperiment was conducted to demonstrate this. The settings were two patients A and B, undergoing a certain surgical procedure and their respective caregivers, C-A and C-B.

Patient A

Consent & Pre-op

C-A: (anxious), Hey doc, ya think he’s gonna make it?

Doc: It’s difficult to say and I don’t know that at the moment. There are studies indicating that 95% live and 5% die during the procedure though.

C-A: ohhh kay (slightly confused) (murmuring)…’All this stuff about knowing medicine. What does he know? One simple question and he gives me this? What the heck has this guy spent all these years studying for?!’

Post-op & Recovery

C-A: Ah, I just heard! He made it! Thank you doctor!

Doc: You’re welcome (smug, god-complex)! See, I told ya 95% live. There was no reason for you to worry!

C-A: (sarcastic murmur) ‘Yeah, right. Let him go through the pain of not knowing and he’ll see. Look at him, so full of himself – as if he did something special; luck was on our side anyway. Heights of incompetence!’

Patient B

Consent & Pre-op

C-B: (anxious) Hey doc, ya think he’s gonna make it?

Doc: It’s difficult to say and I don’t know that at the moment. There are studies indicating that 95% live and 5% die during the procedure though.

C-B: ohhh kay (slightly confused) (murmuring)…’All this stuff about knowing medicine. What does he know? One simple question and he gives me this? What the heck has this guy spent all these years studying for?!’

Post-op & Recovery

C-B: (angry, shouting numerous explicatives) What?! He died on the table?!

Doc: Well, I did mention that there was a 5% death rate.

C-B: (angry, shouting numerous explicatives).. You (more explicatives) incompetent quack! (murmuring) “How convenient! A lawsuit should fix him for good!”

The Doctor’s Coping Strategy

Although numerous psychology models can be applied to understand physician behavior, the Freudian model reveals some interesting material. Common defense strategies that help doctors include:

Isolation of affect: eg. Resident tells Fellow, “you know that patient with the …well, she had a massive MI and went into VFib..died despite ACLS..poor soul…so hey, I hear they’re serving pizza today at the conference…(the conference about commercializing healthcare and increasing physician pay-grades for ‘a better  and healthier tomorrow’)”

Intellectualization: eg. Attending tells Fellow, “so you understand why that particular patient bled to death? Yeah it was DIC in the setting of septic shock….plus he had a prior MI with an Ejection Fraction of 33% so there was that component as well..but we couldn’t really figure out why the antibiotics didn’t work as expected…ID gave clearance….(ad infinitum)…so let’s present this at our M&M conference this week..”

Displacement: eg. Caregiver yells at Fellow, “<explicatives>”. Fellow yells at intern, “You knew that this was a case that I had a special interest in and yet you didn’t bother to page me? Unacceptable!…” Intern then yells at med student, “Go <explicatives> disimpact Mr. X’s bowels…if I don’t see that done within the next 15 minutes, you’re in for a class! Go go go…clock’s ticking…tck tck tck!”

We believe there are other coping mechanisms that are important too, but in our observations these appear to be the most common. Of the uncommon ones, we think med students as a group in particular, are the most vulnerable to Regression & Dissociation, duly accounting for confounding factors.

All of these form a systematic ego-syntonic pattern of behavior, but for reasons we are still exploring, is not included in the DSM-IV manual’s section on Personality Disorders.

CONCLUSIONS:

Patients and their caregivers seem to think that ALL doctors are fundamentally inept, period. Ineptitude follows a wide spectrum however – ranging from the bizarre to the mundane. Further studies (including but not limited to arm-chair pontification) need to be carried out to corroborate these startling results and the factors that we have reported. Other studies need to elucidate remedial measures that can be employed to save the doctor-patient relationship.

NOTE: I wrote this piece as a reminder of how the doctor-patient relationship is experienced from the patient’s side. In our business-as-usual frenzy, we as medics often don’t think about these things. And these things often DO matter a LOT to our patients!

Copyright © Firas MR. All rights reserved.

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Comprehending Drug Concentrations and Dilutions

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Good medical practice requires you to make sense of drug concentrations and dilutions!
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Bonjour! Every year, an unprecedented number of casualties result from errors made by medical staff in administering drugs based on faulty dilutions. Besides human error, a lack of standardized methods for the representation of drug concentrations, contributes significantly to this preventable morbidity and mortality. Today, I will very briefly be discussing, some of the basic rules for calculating drug concentrations & dilutions.

Drug concentrations, when put as percentages (%), either mean weight/weight (w/w %), weight/volume (w/v %), volume/volume (v/v %) or part/part percentages. Furthermore, the denominator in each of these fractions could either stand for the solvent, or the solution as a whole. So, suppose you see a dilution that says 1:1000 (or 1/1000) of 1% lidocaine, which of these fractions apply? To take the complexity up a notch, consider how many milligrams of epinephrine and lidocaine are contained in 50 mL of a 1:100,000 solution obtained by adding 0.1 mL of 1:1000 epinephrine to 10 mL of 1% lidocaine. Understandably, novices find such questions extremely frustrating enigmas.

The key to understanding (i) concentrations & (ii) dilutions, is to engrave in one’s mind the following conventional rules:

  • Concentrations:- x % of a drug denotes x grams of the drug (or solute) in 100 milliliters of the solution. Eg. 1% lidocaine contains 1g of lidocaine in 100 mL of solution.
  • Dilutions:- Anything represented in an x : y (eg. 1:1000) fashion, is x grams of drug (or solute) divided by y milliliters of solution. Eg. 1:1000 of an epinephrine solution contains 1g of epinephrine in 1000 mL of the solution.

Keeping these cardinal rules in mind, problems such as the above are a piece of cake. With them, you have blissfully attained nirvana! Let us now break down the second sample question:

0.1 mL of 1:1000 epinephrine contains 0.1 mg of epinephrine. 10 mL of 1% lidocaine contains 100 mg of lidocaine. By adding 0.1 mL of 1:1000 of epinephrine to 10 mL of 1% lidocaine, you are in effect adding 0.1 mg of epinephrine to 10 mL of solvent (in this case, lidocaine) with the resultant volume of solution being 10.1 mL. In other words, when you’ve done this, you will have gotten

0.1 mg of epinephrine in 10.1 mL solution

= 0.0001 g of epinephrine in 10.1 mL solution

= 1g of epinephrine in 101000 mL solution

Mathematically, the exact dilution thus obtained would therefore be 1:101000. This is approximately the same as a 1:100000 dilution, that we would’ve obtained had we dropped 0.1 mL from our 10.1 mL final solution volume value. So congratulations, you’ve now successfully made yourself ~ 10 mL of a 1:100000 solution of epinephrine using 1% lidocaine!

Again, because 10 mL of the solution contained 100 mg of lidocaine, 50 mL of such a solution would contain [100 x (50/10)] milligrams of lidocaine = 500 mg lidocaine.

Similarly, because 1:100000 epinephrine solution means 1g of epinephrine in 100000 mL solution, 50 mL such a solution would contain [1 x (50/100000)] grams of epinephrine = [1 x (50/100000) x 1000] milligrams = 0.5 mg of epinephrine.

Seeing how easy this is, you can now dabble around with quirky questions such as:

  • How many milligrams of epinephrine are present in 100 mL of a 1:35000 preparation? (Hint:- 1:35000 means 1g of epinephrine in 35000 mL of solution.)
  • 5 mL of 1:1000 epinephrine is added to 10 mL of anesthetic solution. What is the resultant dilution of the final preparation? (this is a modification of our sample question)
    • Previously, we had a final solution volume of 10.1 mL and neglected the 0.1 mL (arriving at 1:101000 ≈ 1:100000) because it was too minuscule to make a difference. In the present case, the final solution volume comes to (5+10 =) 15 mL, which is significant enough to not ignore. 1:1000 epinephrine contains 1 mg per 1 mL of solution; 5 mL of solution would therefore contain 5 mg of epinephrine. So, this comes to 5 mg of epinephrine in 15 mL of final solution = 1 mg in 3 mL = 0.001 grams per 3 mL = 1:3000. See, it’s peace!

For more on concentrations and dilutions, you might want to look at an article from eMedicine.com here.

As you read your textbooks, you’ll come across drug dosages in some of these forms that ought to be remembered for applying to patients. Before you mindlessly swallow such information, take a step back and check to see if everything adds up. Know whether using an approximation in the calculations is likely to significantly alter your results and if that could affect your treatment. I happened to come across numerous errors from a pediatrics textbook that our school prescribes, namely “Essentials of Pediatrics by O.P. Ghai 6ed” with regard to concentrations & dilutions. As an example, Table 7.2 under ‘Neonatal Resuscitation’ says that 1:10000 epinephrine, which is the concentration that’s needed for neonates, can be prepared by adding 0.5 mL of 1:1000 epinephrine in 5 mL of solvent (in this case water or something similar such as saline). Although this might be due to a typographical error in the book, the approach is clearly flawed. In having done so, what you would’ve gotten would be 0.5 mg of epinephrine in a 5.5 mL preparation = 0.0005 mg in 5.5 mL preparation = 1:11000 dilution. Given a neonate’s low body weight and the average listed dosage as 0.2 mL/kg, this doesn’t affect the final dosage the patient receives much, only reducing it by 0.002 mg/kg. Such an error would’ve been unacceptable had the patient been of a considerably larger body weight, as in a massive adult, so as to cause small decimal errors to add up to significantly larger ones. You could easily have obtained a 1:10000 dilution by adding 0.5 mL of 1:1000 epinephrine to 4.5 mL of solvent in your garden-variety 5 mL syringe.

With that, you’ve come to the end of this post. Readers are welcome to send in their comments. Until my next piece, adieu!! 🙂

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http://commons.wikimedia.org/wiki/Image:Bb-clockface.pngJust a thought:- Einsteinian physics holds that in the enormous space-time fabric, you, I and everything else in the universe are traveling at the ‘speed’ of light!! Relative to a given frame of reference, that is. Some of this speed goes into our movement in ‘space’ while the rest of it goes into our movement through ‘time’. And because we only have a limited amount of speed (namely ‘c’ or the speed of light), the faster we move through space, the slower our speed through time becomes as seen from that frame of reference and/or observer. If you had to celebrate your birthday with your family in 6 months earth time, but couldn’t physically be with them on earth because you had to attend to a mission on the international space station for the present year, your family would celebrate your birthday later than you would on the station as seen from their frame of reference! To them, your clock ticks slower than theirs. That’s because the ISS & its crew move faster through space than humans on earth. Read more on the time dilation phenomenon here and here.

Copyright © 2006 – 2008 Firas MR. All rights reserved.

Written by Firas MR

July 10, 2007 at 1:57 pm