25 Jun 2009

Bleeding

AJ and I attended an investigator meeting last Saturday. During coffee break, he mentioned how the recent NovoSeven incident might affect their department policy in the future.

The story goes like this. Two weeks ago, there was a road traffic accident. A young lady suffered from pelvic trauma and was sent to a major hospital in town. Because of severe internal bleeding, the attending doctor suggested to use a drug called NovoSeven. However, this drug was not provided by public hospitals for this indication, and the family members had to pay for it. The family members paid but were unhappy with the arrangement. On second thought, they filed a complaint to the Hospital Authority.

At this time, the news has already been spread by the media. The Hospital Authority did not support the doctor either. The administrators quickly refunded the family members. According to the news, his behavior was commented as inflexible and inappropriate.

In the following days, politicians and columnists were quick to demonize the attending doctor. He was portrayed as apathetic and unkind. In addition, he was compared to physicians in Mainland China who refused to save patients if they had no money.

I can understand the reaction of the public. After all, it is scary if healthcare providers may not do their best during life-saving situations because of monetary reasons. However, fundamental questions were largely ignored. Did the emergency doctors withhold life-saving procedures at the time of discussion? Does NovoSeven work?

To my horror, whether the drug works was never the focus of discussion. Even politicians with medical background thought drugs with potential benefit (but not supported by evidence) should be given liberally during emergencies. In the era of evidence-based medicine, all medical treatment should be based on the best available evidence. The medical literature is full of examples of therapies with theoretical benefits that turn out to do more harm than good.

So, does NovoSeven work?

NovoSeven is recombinant factor VIIa. It serves the function of coagulation factor and makes the blood clot. It has been registered at the US Food and Drug Administration for the treatment and prevention of bleeding in patients with hemophilia (I left out the technical descriptions for simplicity). Apart from hemophilia, studies have shown improved functional outcomes among patients with intracranial hemorrhage treated with NovoSeven. In a randomized controlled trial of 301 patients with trauma and severe bleeding, the administration of NovoSeven, as compared to placebo, reduced the need for blood transfusion, but the difference in deaths and critical complications was not statistically significant.[J Trauma 2005;59:8-18] The absence of survival benefit was confirmed by a few other retrospective series. In other words, you probably can spare trauma patients from the drug by providing adequate blood transfusion and yet still achieve the same outcome.

At the end of the discussion, AJ was still worried that his patients with gastrointestinal bleeding would force him to provide the drug.

“Don’t worry,” I answered. “Level one evidence failed to show that the drug improves outcomes in patients with variceal bleeding.”[Gastroenterology 2004;127:1123-1130]

18 Jun 2009

Assessment

I revisited 資治通鑑 during my holidays in early June. This time, I started from the preface. To be exact, this was the letter to the emperor explaining the background of the work (進書表).

As expected, a significant proportion of the preface was devoted to thanking the previous and present emperors for ordering him to accomplish the work and all the support. Interestingly, Sima Guang (司馬光) also thanked the emperor for not asking for staff development reports and research assessment exercises. (前後六任,仍聽以書局自隨,給之祿秩,不責職業。)

As a young academic in the 21th century, I was utterly amazed.

11 Jun 2009

Light

Last Saturday, my wife and I watched Angels and Demons. Overall, the movie was entertaining. The scenery in Rome brought us happy memories of our previous trip.

Compared to The Da Vinci Code, the clues and mysteries in this work were a bit thin. Robert Langdon must be very lucky to get the secret path right.

In this story, terrorists disguised as members of the secret organization of Illuminati stole a canister containing some antimatter, which was supposed to be a dangerous substance that could produce huge explosion. To create fear, the terrorists hid the canister somewhere in Vatican City and transmitted its image to the police. The job of Robert Langdon and the police was to find the canister as well as the people behind the plot.

They soon thought of a good idea. By turning off lights at different parts of Vatican City one at a time, they could roughly locate the canister when the TV image became dark. The trouble was there were too many areas in the City and they only had four hours. The canister would probably explode before they could locate it. Nevertheless, the police decided to proceed, slowly but surely.

At this point, I could not help thinking, “Hey, this is a simple IQ test. Four hours is more than enough.”

Do you know how?

The correct approach is to turn off half of the lights in the whole City. If the canister is in the dark side, you have already excluded half of the City. Then you turn off half of the lights in the remaining part, so on and so forth. Repeating the exercise ten times is equivalent to testing 2 to the power 10, or 1024 spots. Repeating the exercise twenty times is equivalent to testing 1,048,576 spots. They should even have time to send the canister back to the physics lab.

This is the power of amplification. Solving a simple problem in a movie is of course nothing. Honor should go to Kary Mullis, who invented the polymerase chain reaction just by thinking about these numbers.

4 Jun 2009

Happiness

This week is our fifth anniversary. It seems appropriate to write love stories.

One day, Plato asked Socrates what love was.

Socrates said, “Go across this field, and pick the biggest and best ear of wheat. Remember one thing. You cannot go back and have only one chance.”

After a long time, Plato came back with nothing. Socrates asked what happened.

“I once saw some big and nice wheat, but wondered if better ones were yet to come. So I just passed by, but the later ones were not better than before. Thus I had nothing at last.”

Socrates said this was love.

The other day, Plato asked Socrates what marriage was.

Socrates said, “Go across this forest, cut down and bring back the thickest and solidest tree. Remember, you cannot go back and have only one chance.”

This time, Plato brought back a tree that was good but not very tall or solid. Socrates asked him why.

“I saw many good trees on my way. This time, I learnt from the past and just chose a good one. Though this one was not the best, I was afraid I would get nothing again if I did not do so.”

Socrates said this was marriage.

Some days later, Plato asked Socrates what happiness was.

Socrates said, “Go across this field and pick the most beautiful flower. Remember, you cannot go back and have only one chance.”

Plato did so and came back with a fairly pretty flower.

Socrates asked him whether this was the most beautiful one.

Plato answered, “I saw this flower, thought this was the most beautiful one and picked it. Even though I saw many beautiful ones afterwards, I still believed this was the most beautiful one. So I brought it back.”

Socrates said this was happiness.

The story did not stop here.

My wife asked, “Do you dare say you agree with the story?”

“Yes,” I replied, “but I always have beginner’s luck, and have already found happiness.”