Saturday, July 29, 2006

5th Week Report

Some statics for the surgery operated in OR10

The period is selected from 05/01/06 to 08/02/06. During this period, there are 181 surgery operated in OR 10. Among them, 32 are Open surgery; 10 are Angio/Open surgery; the rest( 139) are Angio surgery.
Among the open surgery: 6 for bypass; 6 for endartectomy; 5 BKA; 3 for toe amputation;1 for hepatectomy; 3 for embolization;1 for port placement; 1 for vein abulation, 3 for debridment, 3 for amputation, 1 for AAA; 1 for pyloral; 1 for closure open wound; 1 for verin stripping; 3 for LLE angio, 1 for foot debrigment; 1 foravulation.1 for lt carotid
For angio surgery:
endograph: 12
by pass: 4
bilat carotids:8
ICA:6
aortogram:2
embolization:4
carotiel diagnoste: 5
celiac angio:2
renal AVM:3
lysis: 16
atherectomy:1
angioplasty ;4
hypogastic embo:1
sobclavian gupshot:2
removal of lt picl:1
The rest are for PTA:
1 for PTA renal; 35 for PTA plus stent; 1 for PTA zliac. 28 for PTA; 1 for ICA, 1 for ICA plus stent; stent 4; 1 for carotid plus stent; 1 for PTA PLUS STENTand carotid

The attending surgeons worked in OR10 are: Dr K.Craig Kent(44 cases), Dr Peter Farries(54 cases), Dr Harry Bush(24 cases),Dr John Karwowski(59 cases); the fellows are Dr Stephanie C Lin, Dr Brian Derubertis, Dr Russell Lam, Dr Soo Rhee

For surgery operation time, 1 less than 1 hour; 39 between 1 and 2 hours; 69 between 2 and 3 hours; 39 between 3 and 4 hours; 17 between 4 and 5 hours; 10 between 5 and 6 hours; 2 between 6 and 7 hours; 3 bwtween 8 and 9 hours; 1 between 9 and 10 hours

I could get 80 patients' DOB( there are all the information in the database), there youngest one is 30 and the oldest one is 93. There are 2 between 30-39; 3 between 40-49; 9 between 50-59; 20 between 60-69; 26 between 70-79; 17 between 80-89; and 2 between 90-99.


Some conclusions:

1, for vascualr surgery, the majority is angio surgery and the doctors try to avoid to do the open surgery.
2, for angio surgery, the first choice is PTA. Due to the stent failure problem, the doctors will try PTA first, if the effect is fine, the stent would not be needed.
3, most of the patients are old people above 60, so the happen rate of vascular disease is growing greatly with the age, especially for people above 50.
4, for the operation time, most of the cases are in the range of 2-4 hours. Among them, the angio surgey is also in the range, but the angio surgery for detection of the blood blot site will cost longer time. For open surgery, such as bypass or AAA graft, normally they would cost longer time, above 5 hours.
5, smoking history is a big issue for the vascular problems, although I do not have all the patients' data to anylyse
6, diabetics disease is another issue for the blood clots formation.
7, for every attending surgeon, the average operation time is close. Dr Kent is the chief of vascular surgery division and the president of American vascular society, so he has to spend more time on the public affairs.

Friday, July 28, 2006

Ben Hawkins: Week #4

In addition to rounds and other activities, I was able to tour the laboratory facilities of the hospital. Dr. Richard Lent is Associate Professor of Clinical Pathology and Laboratory Medicine, and is in charge of the facility. The laboratory processes tens of thousands of samples everyday, everytime a sample is sent out for blood gases, pH, createnine, white cell count, red cell count, platelets, or virtually any common test is sent to this facility. Every part of the process is automated, from the moment it enters the lab, and the closed sample is placed in the line, it is moved, processed, and stored without making contact with anything but a sterile machine. The sample is introduced closed, tracked by bar code. After the sample is taken from the patient, the bar code is recorded and associated with the patient. The tests are ordered based on the bar code as well. Once the sample is introduced to the automated testing lab, the bar code directs the routing and testing of the sample. If its a serum test, the sample is centerfuged and directed to the appropriate station. Each station runs a large variety of tests. The outputs are generally chomatographic, and a reader compares color and intensity to a baseline calibration. The results are processed automatically and reported through the computer system so the doctors and nurses can view the results the instant they are available. The samples are stored automatically in a refrigerator unit for up to a week. If the results are outside a predefined margine, the machine is retested against a known sample, and the original retested.

This testing center is formidible and can quicly process a large number of samples, runs every hour of every day of the year, but there are still some tests that are not automated because they require more exotic reagents, complicated protocols, or special sample treatment or result interpretation. These are the tests that can benefit from new engineering technologies. This is where my research leads and contributes so I found this interaction very insightful. I am going to attempt to spend time shadowing a lab technician in the next week.

Daniel and Alecia present the Case Studies

Daniel's project with HSS was to perform a case study on an explanted total shoulder implant and determine the cause of failure.
















Daniel was given the actual implant to study. The metal piece is the humoral head component of the implant, and the plastic piece is the glenoid component, which has been subject to wear.








Dr. Timothy Wright shared a lot of valuable insight into Daniel's case as he discussed his own thoughts.











Alecia's case was an explanted total hip replacement. The implant had cracked and Alecia had to determine the cause of failure.














The implant was removed from a woman who had lived with the implant for 17 years. She began to experience pain and the doctors discovered that the implant was loose.

Miscellaneous Week

Dr. Potter had the week off so I was forced to be adventurous and find my own activities for the week. The first event I attended was a talk on BMD in elderly male populations. This talk discussed the correlation between BMD in elderly males and hip fracture. Many variables were investigated including femoral kneck diameter, shaft diameter, BMD, etc. between white and black males. This talk was a little outside my expertise but was a good experience. It is quite enjoyable to be able to extend your knowledge of orthopaedics beyond just your "area" when given the opportunity.

I also attended the musculoskeletal integrity meeting in which a future study on explanted failed femoral heads was proposed. The study was proposed that in ceramic zirconium femoral heads undergo a phase transition from tetragonal to monoclinic. This phase transition is associated with the failure of the implants. The study will involve utilizing raman spectroscopy to investigate the percent of monoclinic phase in explanted and new zirconium heads. This was very interesting to me as I was given a case study of a failed total hip replacement which I will discuss shortly.

I was also lucky this week to be introduced to Dr. Herzog who the chief of telaradiology and is considered the resident expert on spine MRI. We had a lenghtly discussion of the Intervertebral disc, its pathology, and the possibility of developing a tissue engineered implant for the disc like I'm currently working on. He recommended for me to look at some of the papers on the pathology of disc degeneration written by Covington. I am definitely take his advice in this area.

In addition to Dr. Herzog I had another conversation with a research fellow working on the spine. His project involved using adenovirus vectors to introduce BMP-6 and BMP-2 into the IVD region to induce spinal fusion without surgery. This would be a great advancement for performing a normally quite arduous task without having to open up the patient and implant any hardware. I also enjoyed the conversation with him as he was interested in my project and got to discuss the need for a better disc implant. This topic has come up with quite a few people and I definitely am realizing the need for a product like the tissue engineered IVD that I am working on.

I spent quite a bit of time this week going through the medical records for my case study. This has been a fascinating opportunity to try and discover why a patients implant has failed. The case required me to go through 6 folders of medical records. It is studies like this in larger scales that can provide that data of what patients are optimal for such implants. I never thought I would find it fun going through the records but I did. In the process I was able to learn a lot about total hip replacements and the terminology used in their application. Despite this not being my "area", I feel this information gives me a broad based knowledge of orthopaedics that will be beneficial in my career and studies.

Thursday, July 27, 2006

Report 5

Week 5

3 cases

Luckyly or Unluckly for me... I don't see cases where the life is at risk. Even in HSS, in the orthopedics surgeries, we can say that the life of the patient is "SAFE" because if it wasn't, the doctors don't perform the surgery... ( a person can live with out arms and legs) So, I didn't see anybody dies, I am fine because I get sad even when I read the description of your cases.

So I will describe 3 random common cases that I saw during the week in the neuropathy center. The procedure is very methodic (I explained it in past blogs), but the challenge in this kind of tests is interpret the results and remember the anatomy... I am not good on this... I am making a summary of the interpretations that the doctor did before I forget it.

1
A 50 years old woman with a 6 month history of intermittent numbness and paresthesias in her hands was the patient. The electrophysiologic test was performed to evaluate for a median neuropathy, cervical radiculopathy and perypheral neurophaty.

1.- Motor nerve conduction, F-wave minimal latencies and sensory nerve conduction studies of the right arm and leg are normal.
2.-The right tibial H-reflex is normal
3.-Needle electromyography of the right deltoid, first dorsal interosseus and C7 paraspinal muscles is normal.

We couldn't do further electromyography because the patient didn't want. So the doctor couldn't conclude anything because the limited nerve conduction and electromyographic findings were normal.

2
A 48 years woman with numbness in her right fifth digit for one year. Complains of neck pain. Her history is significant for ITP and splenectomy, as well as a right wrist fracture more than 10 years ago.

1.Motor conduction studies are significant for a mildly prolonged right median distal latency.
2.-The left median adn bilateral ulnar responses are normal.
3.-F-waves studies are significant for prolonged minimal latencies and chronodispersion in the right ulnar and median nerves.
4.-The left ulnar and median F-waves are normal.
5.-Moderate right ulnar conduction velocity slowing, with a decresased amplitud and severe right dorsal ulnar cutaneous nerve and moderate right median nerve conduction velocity slowing.
6.-Palmar mixed nerve conduction studies are significant for right median nerve conduction slowing.

There is evidence of a mild right median neuropathy at the wrist (carpal tunnel syndrome) Mild sensory-motor dysfunction in the distribution of the right ulnar nerve. The site of dysfunction is likely distal to the branch of the medial antebrachial cutaneous nerve and proximal to the branch of the dorsal ulnar cutaneous nerve.

3
89 years old woman with a 5 year history of preogressive burning pain and stiffness in the legs and 1 year history of progressive tingling in the hands. She suffers from episodic back pain radiating down her right leg

1. Motor nerve conduction studies are significant for an absent left peroneal response with recording from the extensor digitorum brevis and normal response with recording from the tibialis anterior.
2. There is a mild-moderatte amplitude reduction of the right tibial compound muscle action potential, with an increase in duration on proximal in comparison with distal stimulation, suggestive of temporal dispersion.
3.The right peroneal amplitude is reduced. There is an increase in the left tibial duration on proximal in comparison with distal stimulation, suggestive of temporal dispersion.
4. Fwaves are significant for an absent left peroneal response, mildly prolonged right tibial and peroneal F-waves minimal latencies, and left tibial F-wave minimal latency chronodispersion.
5. Needle EMG is significant for sparse positive sharp waves and fibrillations in the right C7 paraspinal musculature. Increased duration motor unit potentials are seen in : bilateral tibialis anterior, gastrocnemius, vastus lateralis, right biceps brachii, and extensor indicis proprius.

The doctor conclude that there is evidence of a patchy motor neuropayhic process affecting the legs an right arm. The right arm is mildly affected, and the legs are mildly to severely affected. The anatomic localization of these findings are uncertain. They may be related to the right C7 radiculopathy, limbosacral polyradiculopathy and a motor polyneuropathy. No evidence of a right median neuropathy at the wrist.

Wednesday, July 26, 2006

EP post

In Cardiac Electrophysiology, ablation is often times used to cure different types of arrhythmias. The concept behind cardiac ablation is relatively simple and some may even consider it an extremely crude and barbaric method of treatment. Essentially certain parts of the heart that routinely contribute in a defined arrhythmia pattern are electrically decoupled from the rest of the heart. This is done by either using cryo-ablation or radiofrequency ablation. As the names imply, cryo-ablation essentially freezes the heart tissue until it no longer conducts electrical impulses, and radiofrequency ablation does the opposite by burning the tissue. Both of the methods have their advantages and dissadvantages. I have seen quite a few ablations since I have been here. The most common have been used for patients with atrial fibrillation.

There are many different theories as to the fundamental mechanics of fibrillation in general, and atrial fibrillation is no exception. However, many would agree that the pulmonary veins can serve as anchor points/origination points for reentrant (reentry - type of tachyarrhythnia) waves in the atria. Some recent articles in the journal Circulation that discuss this in more details include 'Catheter ablation for paroxysmal atrial fibrillation: segmental pulmonary vein ostial ablation versus left atrial ablation' by Oral et. al. and 'Atrial electroanatomic remodeling after circumferential radiofrequency pulmonary vein ablation: efficacy of an anatomic approach in a large cohort of patients with atrial fibrillation.' by Pappone et. al. The basic principle is if you decouple the areas around the pulmonary veins, reentrant waves that were created and sustained by the heart issues in these areas could not longer exist and the person would be subsequently symptom free. For those who don't remember, the pulmonay veins are responsible for bringing oxygenated blood from the lungs into the right atrium. A diagram is given below where the 4 pulmonary veins can be seen in connecting to the back part of the right atrium.



These 4 veins can be electrically isolated in multiple ways. Sometimes each of the individual veins are enclosed by an ablation line. Sometimes pairs of veins are enclosed as to make the total amount of ablation circles 2. The number of ablations used to complete the electcial isolation varies. I have seen cases where only 30 or so ablations were used. I have also seen cases were over a 100 are used. These ablations are carried out using rather sophisticated mapping software. The technology that the software 'Carto' uses enables clinicians to map out the atrium. This is done via the following setup.



picture obtained from http://www.jjmp.ca/images/bwi_us_plan_cartoxp2-2.jpg


The details are not that important to the overall use of the Carto system (actually, to an engineer as myself, they are, but they will take too long to go over). With the use of three magnets placed below the patient, a reference catheter, and a 'mapping' catheter, the clinician and technician on hand are able to recreate an image of the atrium. The are then able to overlay this image with a CT scan image to better their overall picture. The clinician will go by the produced image to know where to ablate because going by simply feel and the image produced by the flouroscopic unit x-ray is not sufficient. An example Carto image is shown below.



adapted from http://www.pennhealth.com/phys_forum/pto/sep_oct05/ablation.gif

In the image, the blue vein looking structers are the pulmonary veins. The red dots indicate regions where an ablation has taken place. I asked the doctor what they did about atiral fibrillation cases before the use of technology like carto. He replied that these sorts of opperations were simply not feasible. The combination of technology and medicine is on prime display everything one of these procedures takes place.

More information about the Carto system and related topics can be found on the Johnson and Johnson website - http://www.vapr.com/home.jhtml?loc=CAENG&page=viewContent&contentId=09008b988073ddc8&parentId=09008b988073ddc8

Today I saw a dying patient

Actually today's clinical examination was going very well.
There is no difficulty patients today. Some patients came back for check. The results are very good.They seem recover well.
I am really happy they get good surgery operation and recover well. I saw one patient for at least four times( you could find my description in my previous post). She is an old russian speaking woman. At the first time, her whole leg and foot are cold. After surgery, it's warm now.
For the patient going to die, I feel very regret. As we know, there are a lot of people die everyday. So the death is common. However, when you see a patient died or even going to die by yourself, it's painful. Uche expressed the same feeling when he saw one patient died last week.
Actually today's patient looks fine and he remembered me. I could not find any difference from him with the normal patients.
Due to his cancer disease, Dr K did not want to do any surgery on his leg and just ask him to take some antibiotics.
After the examination, Dr K told me that this ptient has the cancer for long time and the cancer cells have spread to the whole body. His life would have no more than one month time. Anyway, he showed his dignity facing the death. I hope he will die without much pain. I even wish he could survive. Bless him
Two useful books for reference:
1, Review of Gross Anatomy, 5th ed, Ben Pansky, macmillan publishing company
2, Endovascular Skills, second edition, Peter A. Schneider, Marcel Dekker, INC
the first one is for the general surgery reference and the second is for vascular surgery skill
One good website: www.vascularweb.org
Some kinds of good exercises for recovery:
1, walking
2, swimming
3, bike
Detecting techniques used for vascular surgery:
1, Angio(X-ray)
2, MRI
3, CT
4, Ultrasound

Tuesday, July 25, 2006

Flor Alicia


Dr. Sander and Flor after a nerve conduction test. The M waves can be observed on the monitor.











Room where EMG and nerve conduction tests are performed.

At work with Julius



The doctors have to wear lead for the procedure. Julius puts on his lead vest too.














Julius with Neurosurgery Fellow Kyle Chapple. Dr. Chapple spends time teaching Julius about the brain images and the procedures.








Julius helps adjust the monitors for the Doctors. The display has six separate monitors, some of which are live.
















Dr. Chapple continues to teach Julius as he works.

Monday, July 24, 2006

Pediatrics with Ben

Ben went on rounds with the doctor and a few nurses in pediatrics. One of the nurses thought Ben might be undercover "Purell police" checking to be sure that everyone is washing their hands properly.


Ben takes careful notes of what the doctor says so that he can track each of the patients. There are about 18 that he follows.




The doctor examines the patient with a small stethoscope.






Jaundice is common in premature babies since their livers are not completely formed. Phototherapy (as seen here) uses a to alter the form of the bilirubin in the blood.

EP week 4

Normal ECG

ECG with heart block



Before we go into detail on what an EP clinician does, it may be appropriate to explain the major types of abnormal heart rhythms that the doctors aim to rectify. Although it may be true that not every heart condition is the same, it is useful to divide abnormal heart rhythms into two general types: hearts that beat to fast (tachyarrhythmia) and hearts the beat to slow (bradyarrhythmia).


Bradyarrhythmia:
As was mentioned before, the SA node located in the right atrium is responsible for initiating the electric wave that sequentially stimulates the entire heart from the atria to the ventricles. If this node is not working as is it should, one could guess that problems may arise. As is the case, the SA node is not the only region that can spontaneously and continuously generate electric pulses, however. The cells that comprise the AV node are also capable of this function. However, the intrinsic 'beat' rate of the cells in the AV node are slower than that of the SA node. This may or may not be a serious medical problem depending on the patient and other extenuating circumstances. Also, it is possible that the electrical conduction system be 'disconnected' at a certain point along the desired pathway. This type of bradyarrhythmia is often times referred to as 'heart block.' A typical ECG of someone with heart block is shown above. The major difference is the prolonged duration of the PR interval. If you remember what was said last post, the duration of the PR interval would be obvious, but if you forgot, remember that the P wave is indicative of the deploarization of the atria and the QRS complex is due to the depolarization of the ventricles. So a prolonged PR interval indicates a long conduction time from atria to ventricles. Heart block is further broken down into 3 categories, 1st, 2nd, and 3rd degree heart block. 1st degree heart block is when the conduction through the AV nodes and into the ventricles is slow. 2nd degree heart block occurs when the electrical transmission from the atria to the ventricles is intermittent. 3rd degree is reserved for instances when there is not transmission at all.


Tachyarrhythmia:
The heart can qualitatively beat faster by a number of well-defined mechanisms (and a lot more I'm sure!). The first defined mechanism is automaticity; this occurs when a part of the heart generates its own electrical pulse which essentially overrides the natural function of the SA node. The cycle length (time between pulse initiations) of this tachyarrhythmic origination site will most likely be shorter than the cycle length of the SA node. Another major type of tachyarrhythmias is reentry. The process and the mechanism for reentry is one of the more cryptic and poorly understood phenomena in cardiac electrophysiology. The general concept involves the existence of what is analogous to an electrical circuit by which a depolarization wave can circle around and around indefinitely. This type of circuit and electrical wave combo can prove to be very deadly if located and time correctly. A more comprehensive discussion about reentry can be found in advanced electropysiology textbooks such as 'Cardiac Electrophysiology' by Zipes and Jalife.

In principle, because all electrical propagation is governed by the shape of the action potential, pharmacological therapy aimed at treating patients with these types of heart problems are aimed at changing the action potential parameters. Antiarrhythmic drugs that affect the ion channels will change these parameters. For example, a drug that inhibits the opening function of the Sodium channels, will cause the initial action potential slope to decrease. This decrease in slope means that neighboring heart cells will reach threshold potential (see previous post if threshold potential is not familiar) at a slower rate ultimately causing a slower conduction rate. Antiarrhythmic drugs have been located and classified based on how they affect the cardiac action potential. A lot of the time, surgical procedures aimed at quarantining the 'bad' parts of the heart (such as ablations) are used as therapy. An increasingly utilized method of treatment involves the use of devices, such as pacemakers and ICDs (internal cardiac defibrillators), that monitor and provide electric stimuli when necessary.

After a full electrophysiology evaluation of an individual who has complained of symptoms that may indicate an electrophysiologic ailment or someone with a family history of a well known and defined heart malfunction, an EP clinician may make the decision to utilized one of the many types of treatments on the individual. An assessment of risk is always important because these surgical procedures can be intensive.

Jan Kostecki – Immersion Student but Test Subject Too

So this week started off a little differently than the others have; instead of going to 4 North for 8am rounds, I began the day by going to the 2nd floor GCRC to get a full blood work up. You may be wondering why I needed to get a workup, but this was for Dr. Kizer and his THrombophilia In Cryptogenic stroke (THICK) study. I was recruited by Lily, who is a echocardiology nurse on the 4th floor. The study started off with filling out the standard medical history questionnaire, followed by a round of questions about my background, and a bunch of other paper work that needed to get done. After that I was lead into a room where a nurse was going to take the blood, at first I thought this was going to be like any other blood draw, but it turns out that they needed 15 vials of blood, each vial was only a tablespoon in size, but still 15! I’m normally ok with having my blood drawn, but I’ve never had the need for an IV needle, so when the nurse put the IV in and even before she began to take the blood, I had begun to see stars and soon I couldn’t see at all. This followed by a cold sweat, becoming completely pale, and on the verge of passing out. This whole time I was talking to the nurses and had this big grin across my face, and they thought I was just messing around with them. As soon as they saw me turn white and break out in a sweat they new I was not kidding. I stayed conscious through the whole draw, and regained my vision to see the last five vials get filled up. At this time, the whole room was filled with nurses just talking about what had gone one, suffice to say, I had put on quite a spectacle for the floor. After getting some juice and taking a few minutes to regain my composure, I went up to the fourth floor and by this time news had already spread to Lily who had a good chuckle. I then went in to get my echocardiogram and Lily took her time to show and describe the different parts of my heart, what she was looking at, along with the anatomy of the heart and blood flow. After the basic imaging of my heart was done, Dr. Kizer came in and took saline that had been oxygenated and injected it into the IV that was in my right arm. Upon injection of the saline, the echocardiograms revealed the oxygenated bubbles in the saline as they traveled to my lungs and were then expelled (no need to worry about a bubble of air heading to my brain). The study was to see if there was a hole between the two atria of my heart, and subsequently revealed that I was a normal control patient. The group is still looking for another 300 control subjects, and if you are interested please let me know and I will get you the contact information. A plus side is that the blood work and the echocardiogram are all free, so you’re looking at around $4000 for a whole cardiac work up for free!

After having that fun of a morning, I read MRI images with my clinician (mainly normal hearts so that I could see what a normal heart looks in comparison to a diseased one), and then was lead into the EP lab where I observed the mapping of a patients heart. The patient had passed out a few times and the doctors wanted to know if it was due to a electrical conduction problem (either the heart was beating too slow or too fast). The room looked like a standard catheterization lab where I had observed angiograms, with a slight modification. There was a big black box in the control room and two computer monitors that had about 30 different electrical signals being displayed. Here I was able to observe how the doctors were able to map the electrical signals across the heart and diagnose where the problems were occurring. It turned out that the patients electrical system was function correctly and did not have any abnormalities.

Tuesday through Friday were back to the standard routine of getting up for 8am rounds on 4 North, followed by meeting up with Dr. Weinsaft and reading images of MRI, CT, and nuclear exams. I also attended a seminar for fellows at the hospital on how to read nuclear exams (specifically related to SPECT images). From what I had already learned first hand with Dr. Weinsaft, this was basically a review course for me and I could already pick out the problems in the heart before the presenter got to them.

In addition to reading images through the week, I continued to work on my project. Since I had the list of patients that we would be using for the study, I now had to compile a demographics sheet that had the patients age, previous medical history, family history, and list of medications that they were on before getting their MRI and echocardiograms done. Many of the patient’s records were easy to access and the database entry was straightforward. There was however a handful of patients that did not have their records on file, so I learned how to use the hospitals other database to locate the patients records. In these records, I had to go through them page by page to see what the physicians had listed. This was more time consuming because I had to decipher hand writing of physicians, and what they do say about a doctors hand writing is true: its completely illegible most of the time, but then there are those exception to the rule which makes it so much easier to find the information that you need.

Overall it was quite a eventful and fun week, and I learned many more new things, not only about the medical field, but also about my own physiology.

Listed below are a few pictures of my mentor, Dr. Jonathan Weinsaft and I reading CT images. Basically my days are spent in small room looking at computer monitors.

The God Complex: Truth or Myth

This past week has been very enlightening. From my perspective before this experience, it seemed that surgeons were mavericks blazing a trail into a new horizon. TV made surgeons out to be egotistical maniacs that had the “God Complex.” As my time has progressed here, I have slowly learned of the teamwork needed between all of the people in healthcare to effectively treat a patient. Many patients have multiples issues and it is only with good teamwork by way of great communication that these patients have their best chance of successful treatment. In my experience here at Weill, I have not found a surgeon that could be accused of having a “God Complex.” It is easy to understand why they need so much confidence. As a resident and or fellow, they are constantly torn down by the attending physicians. Yes, it is deliberate but the intentions are not malicious in nature. One of the goals is to create people of strong character who will stand up for what they feel is the best treatment for a patient. Surgery has proven to be a field where aspirants should have a “thick” skin. The surgeons that I have met have been very confident. I am sure that I only want surgeons operating on me that have confidence. I think that there is a fine line between overconfidence and confidence; the surgeons here tread carefully.

Last week proved to be very challenging. There was more of the same but some cases draw a person in more than others. I asked a Neurological Surgery fellow,”How do you not get emotionally attached?” He began telling me a story about his third year in medical school. As he entered an examination room to see a patient, the patient took a deep breath and died before his very eyes. He explained that becoming emotionally vested in the patients that he cared for would be too taxing. Before coming for this Summer Immersion program, I probably would have thought that to be harsh and the easy way out. Now I understand how true his statements are. Each week there has been at least one case in which I felt some attachment. Sometimes your heart can not help caring for patients with compelling circumstances. In my position, shadowing a clinician, I began feeling the weight of this burden. It seems an almost impossible task to carry all of that baggage around. I began thinking about the patients too often. I was vested in their successful recovery. Being vested in their recovery alone would probably be ok, but that’s not life. Recovery is not always the path chosen. Death occurs often and sometimes without warning. I can’t begin to imagine the bag of bricks that I would have to drag around if I became attached the patients that we have seen thus far. Well, enough of that, we are moving on to the fun stuff!

A 36 year old woman was brought to the ER after suffering from numbness on her left side. We were told by her husband that her chief complaint before loosing consciousness was severe headache and splitting pains. For whatever reasons, she thought this would pass but it obviously ended up being more than she bargained for. While in the ER, she had a seizure involving her torso and left leg. This seizing began spontaneously. A CT scan showed an area of hypodensity measuring 3.3 cm with associated hemorrhage. At this stage, it was thought that the patient could be suffering from an AVM. On day 2, a second seizure was observed and treated. The patient’s movement was severely retarded. The patient was transferred to the NYH NSICU. After angiography, it was determined that this patient was suffering from sinus thrombosis. In this condition, a clot, thrombosis, has migrated the vasculature of the head and become trapped in one of the sinuses, venous system for the head. In short, blood was collecting in the patient’s head causing damage to surrounding tissues which resulted in paralysis on the left side.

After review angiography footage, a team of physicians were called in to consult on this case. It was determined that the best course of action would be to wait on TPA (tissue-plasminogen activator) treatment as the patient’s movement on her right side had become better. TPA involved certain risks and it seemed that the IV medications were helping. One of the risks was bleeding around the clot that had formed in the sinus. If this bleeding was unable to be controlled, a vegetative state could be the result. On the other hand, TPA could dissolve some or the entire clot and restore drainage. After no improvement over 12 hours, a couple of rounds of TPA were administered in the NSICU. The patient has improved at his point but is still undergoing treatment. She is a soldier with much to fight for as she is a wife and the mother of 4.

More on TPA http://www.americanheart.org/presenter.jhtml?identifier=4751

fourth week

This week was mostly a repeat of past weeks in what I saw. Recently I have mostly stayed in OR 4 in the greenberg building. This room exclusively does robotic surgery, and transplants. Probably half of what I see is Dr. Tewari doing robotic prostate removal. At this point I know this surgery quite well. the first time I watched it I was totally disoriented and unable to really follow what was going on. Now I can usually figure out what will happen next since I have seen close to twenty of these surgeries either partually, or fully.
Other than that Dr. Sherr does several robotic surgeries a week in that OR, both prostate removal, and tumor removal from bladders or kidneys. Thursday there were two surgeries removing tumors from the ovaries/uterus of patients. These seemed to be more simple surgeries than the usual robotic ones I had seen. The ovaries were much closer to the surface, and less encased in tissue. Therefore the tube attached to the ovaries simply had to be cut, and the tumor removed. The removal of the tumor however was quite a chore. They didn't want to simply cut a hole in the patient big enough to remove the tumor. So, they used a tool called a morselator to remove it. This tool essentially cut a cylindrical strip out of the tumor that was small enough to remove. They repeatedly cut these strips off the surface of the tumor until it had all been removed.
From an engineering standpoint the one thing I noticed that seemed as if it should be easily improved are the clips. In these surgeries blood vessels are clipped off with plastic clips to cut off blood flow to the prostate. The failure rate of these clips is absurd. Probably one in three doesn't close properly and is discarded. Since Dr. Tewari once gave me an estimate that the OR costs around $250 a minute to run, this wasted time seems a silly expense. It is not clear to me however if it is a problem with poor design of the clip, quality control, or a characteristic of the plastic used. It should be possible to remove them.
I emailed Dr. Te earlier in the week, and he was in Washington, returning monday, once I find him in his office, I should start observing some of his surgeries.

Images from Vishal's Day


Vishal looks on with a Doctor at a patient's ultrasound.








The doctor explains to Vishal how the ultrasound is taken.









Vishal looks at an angiogram on the computer.






Now Vishal examines the image with the help of Doctor Priscilla Winchester.




Dr. Winchester and Vishal look at a problematic area that shows up on the angiogram.






Doctor Todd Pullowitz and Vishal looking at CT cross sections on the monitors.






Dr. Pullowitz explains what he is seeing in the CT scan while he looks at it.







Dr. Pullowitz demonstrates the power of CT with a 3D reconstruction.







Vishal's Fourth Week

On Monday, I met with Dr. Weinsaft (Dr. Winchester helped me set this up) hoping to develop a clearly defined project. He introduced me to Dr. James Min, who works primarily with CT. Currently, Dr. Min is beta testing CT analysis software from GE, and would like to display data which shows off the advantages of the software. This is the project I will be working on for the remainder of my time here. Since it involves the analysis of preexisting data, I will be able to make some conclusions by the end of the term, and I will be able to continue working on the project after returning to Ithaca.

[Aside: Dr. Yi Wang mentioned at the beginning of the term that it may be necessary to interact with doctors other than our mentor, or define a project for ourselves in some cases. My experience here is a good example of the former. I started out observing Dr. Wong in the cardiac catheterization labs. Dr. Wang suggested that I also meet Dr. Winchester, who works in a similar field, interventional radiology. Neither of them were doing research, so Dr. Winchester helped me arrange a meeting with Dr. Weinsaft (Jan’s mentor). He introduced me to Dr. Min, who I am now working for. While I lost some time, I made more contacts through my convoluted route, and all of them were very friendly and helpful.]

My project consist of four major goals, some of which I will accomplish here in NYC, some of which I will continue to work on in Ithaca.
• Compare rest perfusion CT vs. Nuclear
• Correlate stress perfusion with coronary artery disease
• Compare CT vs. Nuclear estimates of ejection fraction
• Compare wall motion analysis by CT vs. nuclear

To begin, I went through roughly 400 reports on patients who had CT scans, and queried the nuclear database to find out which of these patients were also diagnosed with nuclear. I identified 124 of such patients. On Tuesday, I began entering the data from the reports on these patients into an online database, and finished entering the data on Wednesday. This information was sent to the nuclear labs, so that the nuclear reports would be pulled and ready within a few days.

On Thursday I observed Dr. Weinsaft and another doctor read CT scans. It is interesting to compare CT to angiography. In angiography, the doctors spend a significant amount of time with the patient in an effort to take a good picture. Once the picture is taken, the doctors can read the image and complete diagnosis in a few minutes. A CT scan, on the other hand, takes only a few minutes to complete, and nonspecifically collects information about the entire heart and chest cavity. However, CT scans are much more difficult and take much longer to read, with experts spending on the order of one hour to complete the prognosis.

On Friday Dr. Min was out giving a talk at a conference, so I took Rachel (our resident photographer) to the interventional radiology lab, and CT reading room to get a few pictures. The doctors were helpful and jovial in front of the camera.

Sunday, July 23, 2006

Ben Hawkins: Week #4

Patient Conditions

Working in the NICU has given me the valuable experience of observing how a patient is treated from the moment they arrive. Arrival, assessment, diagnosis, and treatment. In some cases, I have arrived in the middle of the cycle, and in others toward the end. The cases that arrived after I began are some of the most interesting. I had two new patients arrive this week, with interesting conditions. First, however, I would like to continue my updates on Patients A & B from last week.

Patient A
Patient A is a premature child who came in with respiratory distress. This caused him to be placed on mechanical ventilation. As Evan brilliantly described in his post The Transposition of the Great Vessels there are several 'defects' present in any child in the first few days of life. These usually correct themselves; the ASD, VSD, and PDA all close up due to a change in blood flow and pressure to the pulmonary system. However, in a premature baby there are complicating circumstances. Either due to immaturity of the systems necessary for closure or to complications involving the respiratory system itself (meaning the pressure and flow increases necessary to close the defects are not present), premature children are at high risk for these congenital heart defects. Pateint A had exactly such a situation: respiratory stress caused the PDA to remain unclosed. A ligation procedure was successfully performed to correct the problem. In addition, Patient A responded very well to steriod treatment of his lungs (correcting the source of the problem). However, the lack of oxygenated blood flow, especially to the extremeties caused 'dry gangrene' to appear in his foot. (Upon request, I will happily post pictures of what dry gangrene looks like, but just to warn you, it isn't pretty. I recommend you go here). There are a couple of treatment options, including amputation. In this case, the risk of another surgical procedure is too great, and autoamputation is the desired course. However, if Patient A cannot close off blood flow and the gangrene spreads, surgical amputation may be necessary. In addition to the damage to tissue, x-rays suggest that there may be some damage to the distal tibia. A region of lucency was detected, and upon review by radiology, a skeletal survey was recommended.

The large hurdles, those threatening Patient A's life have been cleared. His respiratory difficulties responded very well to steroid treatment, and the PDA ligation procedure was successfull in closing the shunt between his aorta and pulonary artery. The other consequences of his condition remain, however.

Patient B
Patient B has several difficulties as well, and thus far the underlying cause has not been determined. In addition to ichthyosis (scaly skin) he has atypical hair and growth. He had an infection of the eye causing the removal of his lenses from both eyes. The preliminary test for trichothiodystrophy was negative. Additional tests for thyroid conditions as well as chromosomal anomolies have been ordered and results are pending.

Patient C
Patient C was born with a large growth on his back, between the lumbar and thoracic regions. Initially, it was thought to be a myeleomeningocele, a collection of cerebralspinal fluid, spinal nerve tissue, and meningeal membrane that protrudes in a cyst through the incomplete closure of vertebre. However, the position was cause for concern and an MRI showed that it was diastomatomyelia. In this case, the cyst on Patient C's back was the result of malformation of the vertebra, but in addition to containing spinal fluid and tissue, there is a mouth shaped split of the spinal cord, essentially a hole through the middle, clearly observable in dorsal and sagittal sections of the MRI. While Patient C currently has use of lower extremeties, this may change over time, as growth of vertebra may damage the spine. However, surgery at this point could be more dangerous, and so repair of the defect has been left for later on in the baby's life.

4th Week Report: Clinical Practice

In the 4th week, everything is going well.
As the previous 3 weeks, I spent half time on observating the surgery (OR10) and the rest time in the exam rooms(M014)
I also listened a 1 hour lecture given by Dr K for the 3rd year MD students. The name of the lecture is:Aneurysmal Disease.

Besides the normal stent, balloon and laser surgery, I watched one special surgery for AAA(abnormal aortatic aneurysm). Actually, the chief of vascular surgery , DrK. Craig Kent did a lot of AAA graft surgerys. I have described the detail of AAA in my 2nd post. If the diameter of aneurysm is above 5cm, the surgery is needed. This time, the AAA was removed( some part of it was cut) and a graft( should be made from non degradable and biocompatibel polymer, such as PTFE) was implanted at the site of AAA. This surgery is a big one and three doctors worked together for more than 5 hours.

First they cut the skin and cut further to the site of the AAA. After finding the AAA, they started to clean the surrounding tissue and seperate the blood vessel from the tissue.

During the operation process, I found there should be some digital camera and a large panel showed the clear image of operating. The doctors should wear special glass so that they could watch the detail of tissue.
The follwoing is some X-ray pictures of AAA stents

4th Week Report

4 Week Report

This week was very busy because besides attending meeting and surgeries at HSS and some tests at Neuropathology center, I did research in my projects. For HSS I have to find the cause of failure of a hip implant that they gave me. I am very curious because the implant has a big hole and it was replaced just 6 months ago. Also, during the week I perform an experiment with Dr. Sander at the neuropathology center following the kimura method of one of the papers trying to measure the velocity from the slowest fibers. I also made a protocol about another method proposed by Verna. But the problem of obtain the slowest velocity is not that easy and so far many people are working on it.

A method to measure the velocity from slows fibers in a nerve
(Adaptation of Verna Method)


1.-Obtain the velocity from the fastest fiber using the conventional method.

ISI from the slowest fibers using Collision test

2.-Depending on the nerve that we are going to record, place one stimulator at a proximal site and the other at a distal site. Both stimuli should be of the same amplitude and supramaximal (175 to 200 V)

3. Measure the exact distance between the distal and proximal points.

4.-Obtain the ISI initial = Distance/ Velocity by conventional method.

5.-Apply a first impulse at proximal site following to a second impulse at the distal site after waiting ISI.

6.-The first ISI would be the ISI initial, then the ISI is going to be increased or reduced depending on the response of the screen. (at the beginning always should be increased).

If the amplitude of the first wave is greater to the amplitude of the second wave= Increase until both amplitudes are the same.

If the amplitudes of both waves are the same, reduce the ISI just before the first wave get greater than the first one.

7.- The ISI obtained is the first approximation of the time that the slowest fibers take to go from the distal to the proximal site. Tslowest

Velocity from the fastest fiber using Collision test

8.-Obtain the latency from the first wave. (looking the screen). Thus, the time from the beginning of the graph to the point when the wave begin to raise.

9. Measure the distance between the recording point and the distal stimulation site.

10.-Obtained the velocity of the fastest fiber = Distance / latency

Correction of the ISI obtained

11.- Substract the refractory period to the Tslowest obtained in 7). We get a new value for the Tslowest. See procedure to obtain the refractory period for the same nerve.

12.-Obtain the estimated Velocity for the slowest fibers. Thus V= Distance (between proximal and distal) / T slowest

13.-Comparing the error obtained for the Velocity from the fastest fibers using the collision method against the conventional method, we assume that the error would be the same for the velocity in the slowest fibers, then we applied a factor that correct the error:

Final_ Vslowest= Vslowest/ (Velocity of the fastest fibers using collision/ Velocity of the fastest fibers using conventional methods)

The Final_Vslowest is the velocity from the slowest fibers!!!

Disadvantages:

-The precision of the result would depend on the precision of the velocity gotten from the conventional method.

-It is necessary to apply many series of dual stimulations on the patient.

Needle Electromiography

I haven’t talk about the Needle electromyography test, so I will explain a bit about
it. EMG Nerve test conduction is often followed by a needle electromyography test.
An EMG test help the physician to detect:
• radiculopathies
• plexopathies
• neuropathies
• nerve compression syndromes
• neuromuscular junction disorders
• myopathies

Needle electromyography consists on use very thin needle electrodes to assess the electrical activity of the muscles. In all the cases that I have seen so far, EMG of leg and arm muscles consist of the assessment of the spontaneous activity and the assessment of motor unit potential (MUP). But, the EMG of paraspinal muscles assesses spontaneous activity only because is hard for the patients to control movements on the back.

When looking at spontaneous activity on the muscles the physician moves the electrode around the muscle, trying to find abnormal activity. The patient has the muscle relaxed so we don’t expect to find any activity. Presence of denervation (fibrillation and positive sharp waves) indicates axonal interruption, a major determinant to the completeness and speed of recovery.

In the assesment of the motor unit potential, the patient gives slight voluntary contraction of a muscle that leads to activation of a small number of motor units. The EMG records the potentials generated by the muscle fibers of the units. Normal motor unit action potentials depend on the muscle being examined, and the age of the patient. The number of units activated depends on the degree of voluntary activity. An increase in muscle contraction is associated with an increase in the number of motor units that are activated and in the rate at which they discharge. With full contraction, so many motor units are normally activated that individual motor unit action potentials can no longer be distinguished, and a complete interference pattern is said to have been produced. A loss in the motor unit that occurs in neuropathic disorders leads to a reduction in the number of units activated during a maximal contraction. EMG testing enables disorders of the motor units to be detected and clarified as either neurogenic or myopathic

Conclusion:

The way that the physician uses the EMG to diagnose is based looking at the signal that the motor unit produced, in contrast the method that I have been using to study how force and motion are produced is looking at the signals produced by all motor units, i.e EMG and without considering single units. This is due, because the number of motor units per muscle can vary from 100 for a hand muscle to 1000 or more for a limb muscle. And, still there is not a standardized procedure to interpret the activity of the motor units. But, looking a single motor units, as is performed on the EMG test has been very helpful to identify diseases.

Meanwhile observing this test I have been able to detect many disvantages, for example to obtain good results it is necessary the collaboration of the patient to do the movements as the physician indicate. But if the patient is very sick, it can not control well their movements. Also, it is very easy to deviate the real response due to factors of noise or movement of the needle. For this reason, the test sometimes is too long.

Summary what i did on the week.

- Attend two surgerys of hip
-Attend a talk about problems in ACL surgery.
-Developed an experiment following kimura method and Verne method.
-Obseved some EMG/nerve conduction tests.
-Do research about possible causes of the failure of a hip implant.
-Attended to a Musculoskeletal Integrity Program Meeting to see the research that HSS is doing.

Flor Alicia