Saturday, October 5, 2013

GI Consult Elective

I'll summarize some of the things I read for this elective below. 
Otherwise, I spent my days doing new consults and following up on my old consults. I learned a whole bunch and became clearer in my head that I'm not really drawn toward the procedural side of medicine. GI specialists know a lot of medicine but they are also technically adept at using endoscopes and all the tools that you can put on those scopes these days.


"Long-Term Colorectal-Cancer Incidence and Mortality after Lower Endoscopy" by Reiko Nishihara et all, NEJM 9/19/13

Colonoscopy and sigmoidoscopy are associated with a reduced incidence in left sided distal colon cancer. Right sided or proximal colon cancer is not reduced as much by colonoscopy, a fact that we learned last year. The polyps and other precancerous lesions are much more difficult to see in the right colon due to a different genetic mutation pathway. Cancers that pop up between colonoscopies are likely to have the "serrated pathway" mutations.


"American College of Gastroenterology Guideline: Management of Acute Pancreatitis" by Scott Tenner et all, 7/30/13

- Mild Acute Pancreatitis is self-limiting, does not have organ failure and/or pancreatic necrosis. Patients start eating again within 48hrs.
- Moderately Severe Acute Pancreatitis has local complications (fluid/necrosis) and/or transient organ failure (<48hrs).
- Severe Acute Pancreatitis has two phases:
  1. early (first week) has SIRS and/or organ failure.
  2. late (after the first week) characterized by local complications (peripancreatic fluid/necrosis/pseudocysts)
Diagnosis
1. Two of three criteria
     i) abdominal pain (epigastric or LUQ, constant, radiates to back, chest, or flanks)
     ii) serum amylase (rises in hours, falls in days) and/or lipase (more specific, stays elevated longer)greater than 3X the upper limit of normal
     iii) characteristic findings from abdominal imaging
2. CT and MRI should be reserved for patients who fail to improve clinically within the first 48-72hrs after hospital admission.

Etiology
1. Ultrasound on everybody to rule out gallstones.
2. History of EtOH (need 5 years of heavy drinking? If no, check serum triglycerides.
3. In patients older than 40yo, tumor should be considered.

Initial Assessment and Risk Stratification
1. Assess hemodynamic status.
2. Assess risk (age, obesity, mental status, comorbidities, SIRS, Labs, imaging)
3. If signs of organ failure, admit to ICU

Initial Management
1. Aggressive hydration (250-500mL/hr) is most beneficial during the first 12-24hrs. LR might have some advantages because prevents the hyperchloremic non-anion gap metabolic acidosis that is possible with large volumes of normal saline.

ERCP
do it within 24hrs of admission if cholangitis is sure.
don't do it if there is no evidence of obstruction
MRCP if no jaundice or cholangitis
use stents and NSAID suppositories after ERCP

Antibiotics
Give for extrapancreatic infection.
No role for prophylactic antibiotics
Carbapenems, punolones, and metronidazole penetrate pancreatic necrosis.

Nutrition
Start oral feeding asap when nausea and vomiting resove
Enteral nutrition better than parenteral if PO route not available.

Surgery
cholecystectomy before discharge unless necrotizing in whic case wait until inflammation subsides.




Persistence of Nondysplastic Barrett's Esophagus Identifies Patients at Lower Risk for Esophageal Adenocarcinoma: Results from a Large Multicenter Cohort by Srinivas Gaddam et all





Cyclic Vomiting Syndrome and Abdominal Migraine in Adults and Children by Randolph W. Evans and Chad Whyte
CVS is 5 separate attacks, episodic, stereotypical, vomiting, symptom free between attacks, not attributable to another disorder.
Epidemiology
2% of children
headache/migraine history
slight male predominance

Clinical Features
Four phases to each episode:
  1. well phase without symptoms
  2. prodrome with pallor, sweating, and nausea
  3. intense vomiting
  4. recovery phase
Pathophysiology
similar to migraines, periaquaductal grey matter, autonomic dysfunction.
"brain-gut" disorder mediated by the neuroendocrine system as evidenced by ACTH, ADH, cortisol, and other endocrine substances that rise in serum. CRF is stimulated by stress in the hypothalamus and it leads to delayed gastric emptying due to inhibiting the dorsal motor nucleus of the vagus nerve. TCAs inhibit the promoter activity of the CRF gene, and thus efficacious in treating CVS.

Differential Diagnosis
acute illness causes of nausea and vomiting.

Treatment
Supportive measures (hydration, electrolytes, quiet, dark, ondansetron, benzodiazepines, diphenhydramine.
Sumatriptin can be taken upon onset of episode.
Abortive agents include NSAIDS (ketorolac) and opioids.
Treatment with amitriptyline, venlafaxine

Prognosis
CVS resolves in many children by teenage years. 86% of adults are cured with TCAs.


abdominal migraines 
Epidemiology
slight femal predominance
5-15 years old

Clinical Features
Recurrent , episodic attacks of abdominal pain with associated nausea, vomiting, and or lethargy lasting as long as migraines.
Periumbilical pain.
Often premonition.

Pathophysiology
unknown

Differential Diagnosis
other causes of abdominal pain

Treatment
treated with prochlorperazine and eletriptan
avoid triggers, dietary management
IV valproate
Pizotifen, flunarizine
Propanolol, cyproheptadine.




I also read a whole bunch of textbook chapters from MD Consult, and learned a lot about diarrhea. I am starting to realize that information technology has changed medicine more quickly than the training can keep up with. As a medical student, I am able to become an expert on tiny pieces of medicine relatively quickly in a way that would not have been possible 10 years ago. It makes me think that the fragmentation of care is not really necessary. Why can't a family doctor refer a complicated patient to herself and spend the 3 or 4 hours that are required to access the detailed information about the complex management necessary. That same 3-4 hours will be spent by a slew of specialists who will use the very same resources (or likely have memorized them) to come up with the same answer. It seems to me that family doctors should have yearly exams, rotating through all of the traditional specialties each year, open book, to ensure that they are on top of their game, because they must recognize and diagnose diseases of every organ system. Better yet, patients should start out at specialists (knee pain, go to an orthopedic specialist) and then get referred to family doctors for management of complex, multiorgan/biopsychosocial challenges. Pay scales should be revered accordingly because specialists will actually need much less training than generalists. Training for specialties can be substantially shortened by skipping all the generalized stuff at the beginning. Technical wizardry would be mastered much more quickly just out of high school so why not get those same folks before they "waste their time" learning how to talk about feelings with their patients.


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