State of Mind

State of Mind

Surgical department meeting-CRC chemotherapy presentation by TTY Biopharm company.

It was great to review and get new updates on colorectal cancer chemotherapy. Several interesting points included,
1. FOLFIRI (Ironotecan+5FU+LV) needs lower dosage of Irinotecan (single agent), this helps minimize the toxicity. Irinotecan when used alone at high dosage causes 12% sepsis.
2. Uracil competes with 5FU metabolism. So Uracil can increase 5FU half-life.
3. UFUR (Uracil-Tegafur) has numerous advantages over 5FU: oral, less toxicity than infusin 5FU (less hand-foot syndrome), good for low dose long term usage to suppress tumor angiogenesis, reduce recurrence and prolong lifespan.

Neuro-surgery
First time assisting in surgery
C4/C5 disc herniation, disc removal, spinal nerve decompression and prosthetic disc insertion. Dr. Ding, the neurosurgeon of the case was very encouraging and patient. He taught Nicole and me step by step how to achieve the highest standards in aseptic practice (our patient was receiving a prosthetic disc implant today so aseptic practice was absolutely critical). The steps were
1. Scrub with iodinated soup up to the elbows, make sure to leather up a lot of bubbles
2. Rinse off the first scrub
3. Apply a second scrub, leave the soapy bubbles on
4. Make sure to hold hands up with elbows close to your body, leaving the most distal part of your upper limb higher than the more proximal part (this will ensure “dirty” water dribbles down and way from your hands, keeping your hands the cleanest
5. Dry your self with 2 aseptic towels, starting from the most distal (digits) than work your way up your arms without touching your hands to your arms (you can fold the towel diagonally and then warp it around your wrist, while pinching the two farthest points of the towel with your other hand)
6. Put on aseptic scrub, nurses will assist with tying it in the back for you.
7. Put on aseptic gloves with scrub sleeves inside the gloves to make sure no bare skin is exposed.
8. The area between your clavicles and the stomach is considered aseptic zone; never leave your hands outside of this zone.
He let Nicole and I took the first assistant’s position (this is a spot that only 4th year resident and above have the privilege of standing in during surgery). We took turn in assisting-- holding various tools in place, suctioning the blood and fluid away, and syringe-dripping saline to cool off the tissues while the high-speed electric drill was going through the vertebrae. We looked under the microscope during the surgery as well. The nurses were very nice to us too. I notice what a great relationship doctors and nurses have in Taiwan. They respect and appreciate one other genuinely. Dr. Ding also said that it was the nurses who taught him how to perform aseptic scrubbing in great details.

Brain CT discussion Tentorial subdural hemorrhage
On the CT scan, we could see that hemorrhage was less dense then skull but denser than brain tissues. So it showed up lighter than the brain and darker than the skull.

Diagnosis:
Timing/ sequence is crucial.
Cerebral vascular rupture=> stroke=> MVA
Or MVA=>subarachnoid hemorrhage
Pt Hx: no vascular disease (no HTN, no DM), unlikely spontaneous cerebral vascular rupture, MVA trauma induced subarachnoid hemorrhage more likely

Complications
1. Seizures
a. Acute seizure, within 24 hours-3 days
b. Delayed, after 3 days
c. If no acute seizure, likelihood for delayed seizure is lower
2. Delayed hemorrhage: after 3 days
3. Hydrocephaly
a. Obstruction of CSF resorption through the cerebral sinus
b. Anytime: hours, days, months, years
c. Gradual, not emergent
d. Signs: incontinence, dementia, and unsteady gait
4. Chronic subarachnoid hemorrhage
a. Elderly patient: brain atrophies
b. Hemorrhage is normally resorbed w/ micro-vessels
c. Atrophied brain has les
5. Vaso-spastic stroke/ischemia

Several other topics he covered were (details supplemented with wikipedia content)
1. Sylvan fissure/ lateral sulcus divides the frontal lobe and parietal lobe above from the temporal lobe below. It is in both hemispheres of the brain but is longer in the left hemisphere.
2. The Circle of Willis comprises the following arteries
Anterior cerebral artery (left and right)
Anterior communicating artery
Internal carotid artery (left and right)
Posterior cerebral artery (left and right)
Posterior communicating artery (left and right)
3. 2 in 3 out (sensory in through optic nerve, motor-extraocular movement via oculomotor nerve)
4. 4 in 5 out (Corneal reflex is conducted along with the facial nerve section of the test. Note the sensory innervations of the cornea is provided by the trigeminal nerve while the motor innervation for blinking the eye is provided by the facial nerve)
5. Caloric test: Cold or warm water or air is irrigated into the external auditory canal, usually using a syringe. The temperature difference between the body and the injected water creates a convective current in the endolymph of the nearby horizontal semicircular canal. Hot and cold water produce currents in opposite directions and therefore a horizontal nystagmus in opposite directions.[4] In patients with an intact brainstem:
• If the water is warm (44°C or above) endolymph in the ipsilateral horizontal canal rises, causing an increased rate of firing in the vestibular afferent nerve. This situation mimics a head turn to the ipsilateral side. Both eyes will turn toward the contralateral ear, with horizontal nystagmus to the ipsilateral ear.
• If the water is cold, relative to body temperature (30°C or below (ice water)), the endolymph falls within the semicircular canal, decreasing the rate of vestibular afferent firing. The eyes then turn toward the ipsilateral ear, with horizontal nystagmus (quick horizontal eye movements) to the contralateral ear.[5][6]
• Absent reactive eye movement suggests vestibular weakness of the horizontal semicircular canal of the side being stimulated.
6. The vestibulo-ocular reflex (VOR) or oculovestibular reflex is a reflex eye movement that stabilizes images on the retina during head movement by producing an eye movement in the direction opposite to head movement, thus preserving the image on the center of the visual field. Doll’s eye sign, eyes moving away from the direction of head movement shows that a comatose patient’s brain stem is intact.

L3/L4 disc herniation, decompression surgery consultation with patient’s wife
Dr. Ding patiently went over the MRI scan of the herniated disc in L3/L4. He assured the patient’s wife that they would operate tomorrow. He recommended bilateral disc decompression because patient had symptoms in both legs—numbness, pain, and weakness.

Evening outpatient Clinic with Dr. Chen
Patient with central epigastric pain, relieved by leaning forward. Classical signs of pancreatitis. Elevated amylase and lipase in last report (May) but she was too busy to make F/U appointment with the GI doctor. GB stones may have obstructed the common bile duct, causing enzymatic juice back up into the pancreas, hence pancreatitis. This patient may have developed chronic pancreatitis, so she needed to go to the emergency room to recheck her current enzyme levels.

Dr. Ding is the 5th doctor who told us that medicine is a marathon. We will spend our whole life learning and practicing it. He told us to take it easy, get a feel of what neurosurgery is about and enjoy the learning. He said that when he was a 4th year medical student, he studied an enormous surgical text from first to last page and spent time memorizing surgeon’s configuration of their surgical tools and setup. He realized in hindsight that he needn’t do these things because all learning and challenges will come in due time. I am grateful for these words of wisdom—to prepare my mind for life-long learning. I need not rush to expand my knowledge; a curious and well-rested mind is the most efficient sponge of all!