Week 7: Shock and Awe

It is unbelievable how fast this summer flew by. Week 7 was all about cranking out work on the project and knocking off the last of my hospital bucket list. I spent Monday attending a qPCR seminar and working on the project. I am still working out some bugs in the pulse oximeter, but it is able to detect pulse and I am able to filter and amplify (bottom waveform) the transimpendence amp output (signal from the photodiode after current-to-voltage converter, top waveform).

All day Tuesday was spent with Leah in the Surgical ICU (SICU). It was a busy day with rounds in the morning, followed by journal club, then Trauma conference and lastly Clinic in the afternoon. One of the more interesting cases during rounds was a middle-aged man who came in from another hospital after experiencing a “fall,” which I later found out was most likely “externally induced” in the hospital bathroom. The patient was admitted for resuscitation of hemorrhagic shock and needed an emergency thoracotomy and evacuation of hematoma (blood build-up in the tissue) the following day. Incredibly, the patient seemed to be showing signs of improvement when I saw him. Adding to the “shock and awe” visuals of the week, one of the residents presented a case of “degloving of the foot” at the Trauma conference which even grossed out most of the doctors. In this type of injury, the skin is completely removed from the underlying tissue. This patient in particular had her foot run over by a bus, leaving her toes in a sack of skin and her bone and flesh exposed. OUCH! Later during rounds, I had the opportunity to examine a patient with Calciphylaxis, a horrible disease of unknown cause where everything in the body becomes calcified. This patient had large sores on her abdomen and legs which she kept bandaged. These consisted of both necrotic and infected tissue and looked extremely painful. The patient also had ESRD which is often common in patients with Calciphylaxis. Not much could be done for this patient aside for managing the pain and discomfort and minimizing infection.

The wide spectrum of rare diseases fascinates me and can be a serious challenge for health care providers, especially when there is no known cause or cure. I spent Wednesday with Dr. Girardi in Cardiothoracic surgery, first going on rounds in the Cardiac ICU and then in surgery. Dr. Girardi removed a left atrial myxoma (connective tissue tumor) from a patient with Carney’s complex. This rare genetic disease results in reoccurring tumors of the heart (and other organs) which must be removed via invasive surgical procedures. This patient was on their fourth open heart procedure and already had significant scar tissue, making each subsequent procedure that much more challenging. Dr. Girardi was well aware that this patient was “his problem” for the next 10-15 years and should be operated on accordingly. During the procedure, Dr. Girardi noticed that the patient had tricuspid insufficiency of an unknown mechanism, but nothing could be done to address this at the time. It was incredible how this patient could live a relatively normal life with such a recurrent, multifocal disease; however, the time, energy and cost of treating a disease of this nature must be acknowledged. Seeing cases like this reaffirmed the need for a lot of the research we do in Cornell BME, seeking to understand the mechanism of various inherited diseases so that we can nip the problem at the bud. While excising a tumor from somebody’s heart is very gratifying, finding a way to prevent the tumor in the first place, while this may require a lifetime of diligent research, would be incredibly impactful in the long run. Biomedical researchers and clinicians have a lot to learn from one another’s approaches to addressing disease. If nothing else, understanding the financial, emotional and physical burden of a disease, drives me as a biomedical researcher to do everything in my power to improve the quality of life for others.

Week 6: Electrifying

After weeks of waiting in anticipation, the parts for my project have arrived! Well, some of them at least. The triumph of the week was learning how to control the LEDs of my pulse oximeter sensor (see below) using an Arduino. The pulse ox works by shining light (alternating red and infrared) through one side of the finger and detecting how much passes through, via a photosensor on the other side. Absorption of light at these wavelengths differs significantly between blood loaded with oxygen and blood lacking oxygen, which conveniently allows me to calculate pulse rate. It has been close to five years since my last circuit design project, but I am really enjoying the learning/re-learning process. Plus, compared to my cells back in Ithaca, circuit elements are much more obedient and lower maintenance (in theory at least)!

It is fascinating how the same physics which govern how a circuit operates also govern conduction in the heart. A number of factors can cause a disruption in the normal electrical activity of the heart: electrolyte imbalance, congenital defects, too much caffeine. Luckily, there exists electrophysiological mapping technology to identify the exact location of short-circuits within the heart tissue. I watched a radiofrequency ablation (RFA) procedure where the doctor used the heat from high frequency alternating current to correct an arrhythmia. In some cases, the ablation can be performed using a laser or extreme cold (cryoablation). 

Another case that caught my attention was a patient who was having an exploratory catheter procedure to examine his failing heart. I overheard the doctor say: “This has mortality written all over my forehead.” This particular patient had a history of alcoholism, diabetes, was cirrhotic and had been in septic shock. Platelet count was 60 (low) and dropping. He had previously suffered a heart attack (STEMI- ST segment myocardial infarction) requiring PCI (percutaneous coronary intervention) and now the cath procedure revealed LAD disease, occlusion of the right coronary arteries, distal left main bifurcation disease and a left ventricle ejection fraction of 22% (>55% considered normal). Cardiothoracic surgery deemed an operation too dangerous. After many consults and some deliberation, the patient ended up back in the Cath Lab with Dr. Kim later in the week.

Two days later, I alternated between watching a brain tumor excision with Dr. Schwarz and the follow-up angioplasty procedure to salvage this patient’s heart. While Dr. Kim was prepared to stop after the insertion of the first stent, his colleague urged him to keep going. It ended up as a triple stent angioplasty (see picture taken from my notebook) which could not have gone much better! The brain surgery was also successful. While the procedures themselves are cool, it is amazing to step back and reflect on the implications of these successes, the precious time and quality of life restored to these individuals. 

If the week was not electrifying enough, Ashley and I had the opportunity to shadow the ER from the patient side. Poor Ashley was having heart palpitations, arrhythmias and chest pains which was NOT OK!  After 10 hours of mostly waiting, we left with Ashley feeling loads better and an EKG report showing some delta waves indicative of Wolf-Parkinson-White Syndrome, but nothing imminent. The follow-up cardiology appointments went really well and the arrhythmias, chest pains, even the delta waves disappeared!!?? Thank God Ashley is back to her peppy self and can go back to studying the heart as a researcher instead of worrying about her own! 

Week #5: REMembering another week

This week, I spent some more time in the Center for Sleep Medicine shadowing Dr. Ebben. The most exciting part is meeting with new patients and conducting the standard questionnaire. Sometimes, these resemble Encyclopedia Brown cases where the answer to one key question can diagnose the problem. Other times, the underlying cause remains enigmatic, warranting an overnight sleep study or additional follow-up. 

One case that stands out involved a young lawyer whose inability to sleep through the night began two years ago, the same time she moved into a new apartment (which was purchased by her parents as a real estate investment). She felt guilty knowing how nice/expensive the new place was, yet she wasn’t feelin’ it from the very beginning. Was her problem mostly psychological? An act of rebellion against her parents? Did she coincidently develop a sleep disorder around the same time she moved? Dr. Ebben was confident that her problem was environmental in nature. What was different about this new place? Was it brighter? Noisier? The patient had accounted for these and nothing helped. According to Dr. Ebben, the most likely culprit was temperature. Her new place was on the top floor and lacked a thermostat with a visible readout. High temperatures during the night may prevent the body from efficiently offloading heat, a necessary process for avoiding sleep fragmentation. The patient was excited to hear about another possible culprit and left the appointment with a renewed sense of hope.

In practice, Sleep Medicine is mostly common sense, heavily drawing on logic to solve people’s sleep problems. However, there are many mysteries waiting to be solved, many of which will require advancements in neurobiology. For example, why do some apnea patients still feel chronically fatigued following positive airway pressure treatment, even if the number of times they stop breathing per hour is reduced from ~100 to ~5? Why is the duration of REM sleep correlated with depression? What the heck even happens during REM sleep besides rapid eye movements, muscle atonia and increased EEG activity? What is the relationship between synucleinopathies (e.g. Parkinsons, dementia) and REM behavior disorder (RBD, loss of muscle atonia during REM)? RBD is thought to involve degeneration of the brainstem, which goes from posterior to anterior. Why is there a polarity in disease progression?  It will be exciting to track how sleep science progresses in the upcoming years.

During the past week I also had the opportunity to shadow in the ER with Dr. Ryan McGarry, who is also the director of an award-winning documentary entitled “Code Black” which he filmed during his residency at County Hospital in LA. The most interesting case involved a patient with L4/L5 disc degeneration who, upon receiving an epidural injection of contrast agent and lidocaine, suffered altered mental status within 60 seconds.  I also observed my first orthopedic surgery, coincidently an L4/L5 Transforaminal Lumbar Interbody Fusion. A laminotomy was performed to decompress the spinal cord and all removed bone was ground up (in what I called the Spinuccino machine) and saved for later use in the interbody fusion. The procedure was guided by fluoroscopy and so we needed to wear lead vests.

The weeks are flying by here and it is time to buckle down on my project while checking off all of the items on my hospital bucket list! 

[re-post] Week #1: Sleep studies in a city that never sleeps?

I originally posted this a a comment before I had access to the blog and before I knew what I was doing. So here it is ... 

During my first week, I had multiple meetings with my mentor: Sleep Medicine specialist, Dr. Ebben, who has a background in Psychology and a Ph.D. in Neurology. How does one develop a sleep disorder in the city that never sleeps? I spent all day Thursday pondering that question by shadowing Dr. Ebben and meeting with a slew of patients throughout the day. Apparently, there is a multitude of ways that the mysterious thing we do called 'sleep' can go wrong. Dr. Ebben's interview process (for new patients) gets right to the bottom of the problem and always starts with: "How can I help you?" It was both fascinating and slightly awkward to be in the room during the interview because I really got to know these people quickly. Sleep habits are very personal and often correlate with stress/anxiety, emotional health, lifestyle, romantic life, etc. However, most patients were unfazed by my presence and were simply focused on fixing their problem.  

I met patients with everything from REM-behavior disorder (where the patient acts out dreams) to common sleep apnea. One of the REM-behavior disorder patients reported punching his partner in the face during an episode. In the past, others reported him diving off of his bed face-first (this one required extensive surgery) and boxing an invisible opponent while standing on his bed. Sleep disorders are not only intriguing to study, but they are necessary to treat in order to preserve the safety of patients and their loved ones.

Dr. Ebben specializes in sleep apnea of which there are two types: obstructive (blocked airway due to obesity or anatomical obstruction) and central (more neurological and complicated). Basically, to have sleep apnea you have to stop breathing (for more than 10 seconds), multiple times throughout the night. This can go undiagnosed for years, putting serious strain on the heart and causing seriously-fatigued people! While there is no sure-shot cure, treatment methods exist such as CPAP: continuous positive airway pressure therapy and BiPAP: bilevel positive airway pressure therapy, which can reduce apnea episodes from over 100 times per hour down to below 5. My project for the summer will be to create a novel actigraph device to measure sleep/wake in sleep apnea patients. This week I began putting a parts list together and designing the wearable device.

Other random fun facts I learned:

v Lots of sunlight exposure in the morning will cause someone to go to be earlier. 10,000 lux of light is optimal and the light/dark cycles are most sensitive to light in the blue range of the spectrum. 

v Melatonin is like the anti-sunlight. 

v Slow phase sleep is therapeutically extended by beta hydroxyl butyric acid (aka the date rape drug). Body builders will slip this in with their protein shakes because it jacks up HGH levels. 

I look forward to getting into the OR next week. Somebody hook me up! 

Week #4: Staying on pace

The Medical Intensive Care Unit (MICU, 5-South) is a challenging environment. The first nurse I met there said, “If you can make it here, you can make it anywhere in the hospital.” When I asked how it stacked up against the ER he said, “The ER is heavy, but a different kind of heavy. You have every opportunity here to make a bad impression.” The social component of being a medical caregiver in the MICU is magnified, as most patients are chronically ill and require long-term care. Family members are often anxious and frustrated and rely on clear communication and constant reassurance from doctors and nurses.

In the MICU, I witnessed cases of renal disease, diabetes, cancer, infection and systemic health problems related to obesity. One of the big problems was that of antimicrobial resistance. In these cases, antimicrobial drugs become ineffective and the risk of spreading infection increases. Patients with such infections can end up sequestered in the MICU, which can be both a cost and a space issue. I was impressed by the variety of cases and the versatility of the staff to manage everything that was going on. For example, there was one patient with severe Type II Diabetes who was also suffering paranoid schizophrenia. He stopped eating because he thought his wife was trying to poison him. Another patient had End Stage Renal Disease (ESRD) along with arthritis and an infected leg. Interventional Radiology was called in order to install a vascular access for hemodialysis (all of the past accesses were unusable) before the patient’s BKA (below the knee amputation). Another case involved an elderly patient who the doctors said essentially died weeks ago; however, the daughter refused to let go. From a legal perspective, it is much easier for the doctors to comply with the family, but what is right ethically? One potential engineering endeavor suggested to me by the head resident was to make the Ergotron portable computer “less ghetto.” These systems are big, bulky, require frequent charging and there are not enough of them to go around. Perhaps a tablet-based system with docking stations throughout the wing would be an effective solution.

My adventure for the week continued on the 4^th floor where I wandered into some Cath Lab procedures. I watched an angioplasty (opening up of a blocked vessel) via a balloon catheter inserted through the femoral artery. Another patient scored very low on a cardiac stress test (level 2); however, her cath procedure did not reveal any cardiac abnormalities and she did not need an angioplasty. At this point Ashley and I met up with Jason and traveled across the floor to the Electrophysiology (EP) wing. We ran into cardiologist Dr. Stephen Markowitz who invited us to observe a pacemaker implantation procedure that he was about to perform. The patient had a history of atrial fib and many cardiac ablations. Because of this, her SA node would get stressed and her heart would stop for ~8 seconds causing her to faint. This procedure featured a nice combination of X-ray imaging, biomaterials and surgical skills to get the job done. Dr. Markowitz used the cephalic vein as an entryway into the heart for the pacemaker leads which were screwed into strategic locations in heart wall. The impedance was checked, as well as the voltage threshold required to jumpstart the heart. Aside from some bleeding due to an artery puncture (which was treated using a thrombin/collagen mixture), the procedure went well. With a new pacemaker in place, there is no more need for faint-heartedness. 

Week #3: Brains, babies and bowels

This week began with my very own MRI scan! But don’t worry! I didn’t hurt myself or anything, but rather Dr. Prince opened up the MRI facility for us to learn about the machine. My brain looks healthy and contrary to the belief of some of my peers (not naming any names), I also appear to have a heart (although the image was a bit fuzzy). At the bare minimum, I have a large inferior vena cava (yellow arrow) and in the left image below you can see my kidneys, liver (left) and spleen (right). Not everything was fun and games- one of Dr. Prince’s students scanned my liver in order to optimize a new imaging protocol. My liver and I were happy to be of service.

I am particularly fascinated with the physics behind MRI technology and with how mathematics (Fourier analysis) is used to reconstruct an image from the raw data (k space) containing frequency, phase and signal intensity information. When the body’s water-containing tissues are exposed to an oscillating magnetic field at a specific resonant frequency, excited hydrogen atoms emit radio waves which can be detected. MRI is often the most powerful imaging modality for many applications. 

In addition to brain and body scans, my week was also filled with many interactions with babies, in both the neonatal intensive care unit (NICU) and pediatric intensive care unit (PICU).  In the NICU, I was impressed with how many neonates Dr. Yap’s group evaluated during rounds: ~20 babies! The NICU treats newborns as small as 400 grams (less than one pound) as premature as x22 weeks (gestational age). Since the lungs are one of the last organs to develop, many of the babies need respiratory support and surfactant treatment in order to decrease surface tension and keep the lungs from collapsing. Neonatal hypoglycemia is another common problem that must be treated in order to avoid brain damage. I attended a journal club discussion of “the sugar baby study,” a recent publication assessing whether treatment with dextrose gel was more effective than feeding alone for reversal of neonatal hypoglycemia in at-risk babies. While the study suggested advantages of using the dextrose, it was not without biases and limitations (e.g. failure of the study to reflect the overall population) and the journal club members were reluctant to change their NICU feeding protocol. One thing was clear: there is a need for less invasive, continuous glucose monitoring; otherwise, babies get continuously “sticked,” adding to the many painful procedures already experienced by premature babies.  

After experiencing the NICU, it was time to graduate to the pediatric ICU (PICU) with Dr. Deyin Hsing who was very kind and informative. Two patients stood out during my time there. The first was a girl with Maple Syrup Urine Disease, a disease named for the sweet-smelling urine that contains the lactone, Sotolon which according to Wikipedia may be responsible for the “mysterious maple syrup smell that has occasionally wafted over Manhattan since 2005.” I just thought that smell was rotting garbage. Regardless, this disease particularly affects the Mennonite population and is caused by an inherited mutation in the branched chain alpha keto dehydrogenase complex which is responsible for breaking down the amino acids leucine, isoleucine and valine. It is typically very treatable with dietary modifications, but this patient had a bone marrow transplant and inadequate nutrition. She started catabolizing her own muscle tissue and releasing the amino acids which could not be processed, leading to toxicity in the kidneys and brain. Dr. Hsing informed me that a lab test to detect toxic amino acid levels in blood plasma took days to analyze. Together we explored a solution, utilizing existing data to predict toxicity levels using an osmolal gap concentration calculation (since test for blood osmolality is pretty rapid). Unfortunately, the contribution of amino acid build-up to the serum osmolality was a few orders of magnitude too small to be detectable. Perhaps a solution to this problem can be engineered (project idea???).  

Later in the afternoon, I observed the stabilization of a one-year-old tetralogy of fallot patient following pulmonary valve repair, triscupid repair and PA-plasty. The IV was not woking and a direct line needed to be installed through the femoral. The patient was also “juicy,” meaning that there was a lot of residual bleeding which drained from a set of chest tubes into a Teleflex chest drainage system. I noticed two shortcomings of this system: 1) judicious manual clearing of the (clotting) chest tubes was needed throughout the procedure and 2) a manual calculation of blood loss per hour was needed. While a cost-benefit analysis would be necessary, Dr. Hsing said that a digital readout would beneficial and more precise if available. It took all afternoon and most of the evening to stabilize the patient, but his blood pressure and respiratory function greatly improved by the following day.

To finish off the week, I shadowed the Chair of Surgery, Dr. Fabrizio Michelassi in the OR. The coolest part of this was observing a right hemi-colectomy and having the opportunity to feel the noticeable (order of magnitude) difference in stiffness between bowel tissue and tumor. As someone who studies cellular mechanics, it was incredible to experience this first-hand and to verify what I had learned about cancer biology.

Week #2: Tying not to drop the ball

The week began in rheumatology where I shadowed Dr. Kasturi in the arthritis clinic. I was not expecting a hands-on experience examining patients, but I learned how to identify inflammation via touch, feeling for warmth in the knee or other inflamed areas. One of our patients had been diagnosed with juvenile idiopathic arthritis (RIA) when she was 3 years old. Now 38 years old, she has numerous surgeries under her belt (spinal fusion, wrist fusions, etc) and continues to live in a great deal of pain (especially in her hip). I got to examine her “telescoping digits” -- soft, swollen fingers resulting from joint destruction and bone loss. The patient opted not to get a steroid injection to relieve the pain before going on vacation due to time constraints. While much of the patient's life was confined to a wheel chair, I was inspired by her reliance and positive outlook.

I also attended the “comprehensive arthritis clinic” where a special case is examined in detail by a room full of doctor and students. This week’s patient was a young Chinese girl diagnosed with multicentral carpotarsal osteolysis (aka “vanishing bone syndrome”). This mysterious condition was unknown to the majority of the room. Turns out, it is caused by a mutation in the MAFB gene (codes for a transcription factor/regulatory protein responsible for osteoclast maintenance and renal function). While the patient had many skeletal deformities and considerable wasting in the right hip, there was some reluctance to treat her (e.g. with a hip replacement, etc.) because of her lack of pain and the possibility of infection and further complications. Risk assessment appears to be a HUGE component of medical decision-making and this is one area where biomedical engineers may help design tools/techniques/quantitative methodologies for deciding the best way to intervene and WHEN.

After spending another day with my mentor, Dr. Ebben, meeting with patients in the Sleep Lab, I finally had my opportunity to explore the OR. For those looking to observe surgeries, the best way I have found is to check the schedule for the following day at 4pm at the OR desk (it is not out in the open so you have to ask). Pick a surgery that looks cool and visit the surgeon’s office and speak with his/her assistant (or directly with the surgeon). You might have to get paperwork signed, but you will then be good to go for the following day. Urologist Dr. Douglas Scherr is very willing to have students shadow and he was the first surgeon who I observed.

I watched a robotic prostatectomy which utilized the Da Vinci surgical robot to remove a cancerous prostate. This was one of the craziest things I’ve ever seen. As I quietly rocked out to Adele’s “Set Fire to the Rain” which the OR nurse had put on, I had the eerie feeling of being in a SciFi movie where a large alien octopus was hovering over the body, ready to operate. A dual consul setup enabled a fellow to operate the machine while Dr. Scherr provided guidance and could intervene if necessary (think driver’s ed). Multiple incisions were made and ports were installed to allow the robot to dock and various instruments to be inserted, including a camera probe which provided everybody in the room with the surgeon's view. Dr. Scherr operated the robot using both hands and feet and performed many fine manipulations to cut, suture, tie of blood vessels, etc. In order to gain direct access to the prostate, the bladder was pulled down and out of the way and the vas deferens and seminal vesicles were removed. Equipped with both a monopolar and bipolar cauterizer, the Da Vinci was able to cut and coagulate simultaneously, minimizing the bleeding. Excess blood was removed using a suction. The most intense part of the surgery was when the suction stopped working and Dr. Scherr assertively said, “Okay, everybody STOP.” There was silence. He then gave further step-by-step instructions describing what needed to happen. It was cool to see him in action as the commander and chief of the operating room. While cauterization is an effective tool to minimize blood loss, sometimes it is avoided; for example, on the lateral regions of the prostate where damage to peripheral nerves could prevent the patient from having an erection (that would really be a downer). In addition to the prostate, the lymph nodes were resected and sent to pathology for evaluation. The lymph results will provide a score for metastatic likelihood which can then be used to guide subsequent treatment. The surgery went very well as a whole and the patient should be off to a speedy recovery. 

While the surgical team stitched up the fascae layer and closed the patient, Dr. Scherr moved next door to excise a scrotal mass from a 29 year old patient. Compared to the 4+ hour prostatectomy, this was a simple ~40 minute procedure. The right testicle and the full spermatic cord were removed through an incision in the lower lateral abdomen. It’s nice to know that a sense of humor is welcome in the OR, as the nurse urged the resident not to “drop the ball” as the testicle was transferred into a container for pathology. In addition to Dr. Scherr, Dr. Zarnegar is supposedly another good one to shadow for robotic surgeries and is known for being an innovator, as well as an expert operator.

Sorry for the lengthy post! As you can tell, my week was pretty nuts!