Wednesday, July 28, 2010

Appreciation

TodaY, I felt very tired..... and exhausted .. maybe because I did not have enough sleep. On Sunday, i just slept for 3 hours, on Monday, I just slept for less than 4 hours and on Tuesday I slept for less than 4 hours as well. I came back at 12 30 pm yesterday.. Thanks to my mentor for the experience.. he's a great surgeon. I rarely praise person.. You know that if u are my best friend. hehehe .. poyo ... Btw looking at him, he is deserve to be consultant and having some other position. This is simply my sharing session.. Not for showing off to anyone. I went to operation theater yesterday in the morning until evening. He got 5 cases; 1 breast lump, 3 cholecystectomy ( 2 laparoscopic and 1 laparotomy) and appendicitis (laparotomy). He bought me fried rice even though he was fasting yesterday. It was second attachement with him because I did the attachment with him 3 years ago. After surgery session, we went to gov hospital because he need to teach his student there. He gave me his white coat, asking me to wear it. He said he always where it, but it is ok for me to wear it yesterday. We had almost 2 hours session, discussing about upper GIT bleeding. Good session with him because his explanation was very deep. Then we went to one of the hotel to listen to people who gave some speeches. We got VIP table (maybe because of his position) sitting with other specialist consultant and CEO. It was a good experienced because people attending that session were mostly specialist I guess. I felt inferior! Maybe because I am just a student.. After that event, we went to back to the hospital (not the gov one) and he said that he wanted to visit his warded patient. He sent me back after that. It was 12 30 when I reached my home. On Monday, the day before yesterday, we got one hernia case. But i did not get opportunity to attend because my parents fetch me early today (Because I did not bring my hp, it was my fault). He told me that he finished his operation at 11 pm. Can you see that how he works?
He's really dedicated to his job. I am doubt about me in the future. I hope that I can treat my future patient properly.

Other consultant have inspired me a lot; I would like to call the mentor; they are ophthalmologist consultant and physician & neurologist consultant. They are really good in their field :)

Wednesday, July 14, 2010

The experience

Last night I slept quite early because I was quite tired attending outpatient ophthalmology clinic. There were many patient yet many more to study. When the doctor asked me about the experience that I got, I told him that I really learnt a lot and going to learn more. There are a lot of cases to be discussed here. There first thing to be done was going to the wards. Meeting the doctor in one of the ward, made me felt nervous because I never met him before. He is very young Malay doctor and smart, the only ophthalmologist there. He showed and explained to be the condition of the patient warded here. The first inpatient case was the pus in the nasolacrimal sinus. So he needed to drain the pus out of the duct. Other cases include trauma of the eye. The patient superior palpabrae was hooked with hanger. The doctor’s intervention was to stitch the palpabrae with cutaneous suturing. Next, was the case of the patient with proliferative diabetic retinopathy. The patient’s kidney function has reduced to 10%. For my lecturer’s intervention, he recommended laser pan retinal coagulation technique to maintain the recent visual acuity. According to him, for this advance stage of diabetic retinopathy, the only intervention is not to cure but to slow down the progress of retinopathy. Furthermore, I got phecolytic glaucoma case. I was not that sure what does it mean by phecolytic and will search more about that. Occipital stroke is another cases that lead to visual disturbance.

In outpatient clinic, there a lot of cases to be mentioned. One of the most common cases are cataract and visual disturbance. Other cases include chalazion, macula atrophy, thinning of retina, neovascularisation, neovascularisation glaucoma, uveitis caused by autoimmune disease, trauma, myopic degeneration.

Today, I experienced three operations. All three cases are cataract cases. Two of operations were carried out by local anaesthetic and one was carried out by using general anaesthetic due to patient request. Although the cases were similar, each patient had different presentation. The first patient had lenses removed with some effort due to the hard lenses. The average operation is around 30 minutes. The lenses of the patient was replaced with lenses that is slightly yellowish. According to my doctor’s, some research have proved that light yellow lenses have ability to absorb blue light that are harmful to our eyes. The patient was not that stable emotionally that maybe due to local anaesthetic. By this method, patient can still hear and see the instruments such as conjunctiva’s forceps, scissors, microsurgery knife, ophthalmic knife and many more. The third case was quite difficult for the incision of the cornea. For this case, the doctor showed me directly through the microscope. I am very thankful to the doctor and grateful because I got the opportunity to see that rather than watching the TV connected to the microscope. Basically, the picture was not similar it is clearer in microscope. Ok then, I am very tired now and plan to eat and sleep for a while. Then, I need to study more, so that I do not look stupid in front of my idol. J

Tuesday, July 13, 2010

Preparing for my day in operation theater...

Hope to gain more experience than yesterday that was quite hectic.... (9.00am to 7.00 pm)..

Sunday, July 11, 2010

Gastric Acid Secretion Mechanism

Physiology of gastric secretion.

There are two principle gastric secretory products that can induce mucosal injury- pepsinogen that is secreted by chief cells and hydrochloric acid that is secreted by principle cells. Acid secretion occur under two conditions; basal and stimulated condition. Under basal condition, acid secretion occurs due to cholinergic input via vagus nerve and histaminergic input from local sources. Basically, basal acid secretion follows circadian rhythms with highest level occurring during the night and lowest level occurring in morning hours. In stimulated condition, there are three phases; cephalic, gastric and intestinal. In cephalic phase, the stimuli include sight, smell and taste that activate vagus nerve. In gastric phase, acid secretion occurs through several mechanisms such as distension of the stomach lead to release of gastrin that stimulate gastric acid secretion. Moreover, presents of amino acids and amines in the stomach can directly stimulate G cells. G cells secrete gastrin and gastrin can directly and indirectly stimulate parietal cells. The last phase occur due to luminal distension and nutrient assimilation. Factors that inhibit acid secretion is somatostatin that is released by D cells found in gastric mucosa. Somatostatin act via two mechanism; it can directly inhibit parietal cells or indirectly decrease the release of histamine from enterocromaffin-like cells and gastrin from G cells. Other factors act in counterbalancing acid secretion is neural pathway (peripheral and central) and hormones (secretin, cholecystokinin).

Parietal cells secrete two important products; hydrochloric acid and intrinsic factor. These cells are located in oxyntic glands. There are many receptors associated with these cells such as H2 for histamine, gastrin for cholecystokinin B or gastrin, and M3 receptor for acetylcholine. Activation by histamine lead to the activation of adenylate cyclase and cAMP. Activation of M3 receptor or gastrin lead to activation of phospholipase C/phosphoinositide signalling pathway. Each of these signaling pathways in turn regulates a series of downstream kinase cascades, which control the acid-secreting pump, H+,K+-ATPase. Other receptors found in parietal cells that are important for inhibition of acid secreting pump activity are somatostatin, prostaglandins and EGF receptors.

Large concentration gradient of hydrogen ions in the stomach is generated by H+,K+-ATPase pumps. These pumps consist of two subunits; alpha subunit that contains catalytic site and beta subunits with unclear function. ATP is needed for the function of the secretory pumps. The pumps are located within secretory canaliculi and in nonsecretory cytoplasmic tubulovesicles. Basically, the pumps are impermeable to potassium ions, which lead to inactive pumps in this location.

The chief cells produce and secrete pepsinogen that will be converted into active pepsin enzyme when pH of the stomach is around 2 or less. This enzyme is inactivated in pH 4 and is irreversibly inactivated and denatured in pH 7 or more.

Reference:

1. Harisson's Principle of Internal Medicine, 17 th edition.

Friday, July 9, 2010

The Promise ...

I just came back from shopping mall just now. We bought some stuff to cook for tomorrow. I am going to visit my nephew and going to stay somewhere (not to mention here). By the way, today after a week I was looking for a stuff to buy, with my sister, I finally bought a pair of shoes. Alhamdulillah. I must mention here that I made new record because today i just took less than 10 min to make decision.

Talking about the title mentioned above, I have promise two things; one for my younger sister and another one for my younger brother.

For my Sis, i promised to buy her a GUESS bag if she could get to do two important things; Got the driving license and the second one, I think better keep it secret. :p

For my younger brother, if he could get at keast 3 A, i will buy him a pair of Nike shoes or Jersey ... :) I got my Nike shoes today, and I am very happy for that... :) May Allah bless us...

Thursday, July 8, 2010

Labyrinthine dysfunction.

This causes severe rotational or linear vertigo. When rotational vertigo occur, the hallucination of rotation, no matter the environment or self, is directed away from the side of lesion. The fast nystagmus is directed away from the lesion side and tendency to fall is on the lesion side particularly in darkness or when the eyes are closed. Under normal circumstances, the vestibular end organ generates a tonic resting potential that is equal on both sides. Rotation leads to the increased in firing rate in one side and decreased in the opposite side. The changes in neural activity is projected to the cerebral cortex where it is summed with visual and somatosensory input to produce appropriate conscious sense of rotational movement. After prolonged rotation toward one side, cessation of rotation would reverse the firing rate with the increase in previously decreased side and vice versa.

In diseased condition, the firing rate is altered. Meaning that, there is unequal neural input projecting to the brainstem and cerebral cortex. This condition can be conceptualized as the cortex inappropriately interpret that there is actual head movement without head rotation. Transient abnormalities produce short-lived symptoms. Fixed unilateral deficit, always have adequate central compensation. Compensation depends on connection plasticity between vestibular nuclei and cerebellum. The lesion in brainstem and cerebellum leads to the permanent symptoms when person moves his or her head.

Acute unilateral labyrinthine dysfunction

..
can be caused by trauma, infection or ischemia. The vertiginous attacks are usually brief and leave the patient with mild vertigo for several days. One of the possible causes is herpes simplex virus type 1 infection. Labyrinthine artery, a branch of internal auditory artery, may be occluded and lead to labyrinthine ischemia. The symptoms present include severe vertigo, nausea and vomiting, but without tinnitus or hearing loss.

Acute bilateral labyrinthine dysfunction

.. can be caused to toxins such as alcohol or drugs. Aminoglycosides is one of the example of drug that can lead to hair cells damaged.

Recurrent unilateral labyrinthine dysfunction

.. in association with cochlear symptom( tinnitus or hearing loss) is related to Ménière's disease. When cochlear symptoms are absent, the term vestibular neuronitis denotes recurrent monosymptomatic vertigo. Transient ischemic attacks of the posterior cerebral circulation (vertebrobasilar insufficiency) only infrequently cause recurrent vertigo without concomitant motor, sensory, visual, cranial nerve, or cerebellar signs.

Reference:

1. Harisson's Principle of Internal Medicine, 17 th edition.

Vestibular system.

Vertigo is always occur due to the disturbance of vestibular system. The end organ of vestibular system consist of semicircular canal that is important for angular acceleration and the otholith organ (saccule and utricle) is important for linear acceleration and static gravitational force that provide a sense in head position. Basically, the neural output from the end organs projects to the vestibular nuclei in brainstem via cranial nerve 8. Vestibular nuclei is connected to the nuclei of CN III, IV and VI; cerebellum, cerebral cortex; and spinal cord. Vestibulooccular reflex is important to maintain visual stability during head movement. There are connections between vestibular nuclei to nuclei of CN VI in pons, and nuclei of CN III and IV in midbrain, via medial longitudinal fasciculus. Vestibulospinal pathway is important for maintenance of postural stability. Projections to the cerebral cortex via thalamus provide conscious awareness of head position and movements.

Reference:

1. Harisson's Principle of Internal Medicine, 17 th edition.

Tuesday, July 6, 2010

Enteric (Typhoid) Fever

Epidemiology:

Incidence basis.

i. High incidence: (> 100 cases per 100 000 population per year) – South-central and Southeast Asia.
ii. Moderate incidence: (10 – 100 cases per 100 000 population per year) – Remaining Asia countries, Africa, Latin America, and Oceania( excluding New Zealand and Australia).
iii. Low incidence: (<10 cases per 100 000) - Other countries.

Endemic region – This disease is more common in urban area and more common in young children and adolescent.

Multi Drug Resistance – In China and Southeast Asia- bacterial containing plasmids that encodes for chloramphenicol, ampicillin and trimethroprim.

Etiology:

S. Typhi and S. Paratyhi serotypes A,B and C.
Transmission:
Food-borne or water-borne results from fecal contamination by ill or asymptomatic chronic patients. Sexual transmissions between male partners have been described as well.

Risk factor:


i. Contaminated water or ice.
ii. Ill household contacts.
iii. Foods or drinks purchased from street vendors.
iv. Poor assess to toilet or hand washing.
v. Raw fruits or vegetables grown in fields fertilized with sewage.
vi. Evidence of previous Helicobacter infection (in association with the decrease in gastric acidity (chronically)).

Host
: Human

Incubation period: Average 10 -14 days but range from 3 to 21 days.

Clinical manifestation:


i. Prolonged Fever (38.8 degree Celsius to 40.5 degree Celsius). - > 75%
ii. Abdominal Pain – 30 – 40 %

Abdominal symptoms:


i. Anorexia (55%)
ii. Abdominal pain (30 – 40 %)
iii. Nausea (18 – 24%)
iv. Vomiting (18 %)
v. Diarrhea (22 – 28%)
vi Constipation (13- 16 %)
Maculopapular rash (rose spot)

Late complication (3rd to 4th weeks):

Intestinal hemorrhage.
Intestinal perforation.

Complication:


Endocarditis, myocarditis, pericarditis, disseminated intravascular coagulation, glomerulonephritis, pyelonephritis, haemolytic uremic syndrome, pancreatitis, orchitis, parotitis, hepatitis, hepatic and splenic abscesses and granulomas, arthritis, osteomyelitis.

Diagnosis:

i. Culture:

a. Blood (Sensitivity is 90% in the first week and become 50 % in the 3rd week)
b. Bone marrow (Sensitivity is 90 % despite of 5 days or less antibiotics treatment)
c. Intestinal secretions.
d. Stool (60 -70 % negative in the first week and can become positive in third week in untreated patient)
e. Rose spot.

Lab test:


i. Leukopenia and Neutropenia
ii. Leucocytosis ( more common in children, the first 10 days of illness and in cases complicated with intestinal perforation or secondary infection).

Non specific:

i. Moderately Elevated liver function tests
ii. Moderately Elevated muscle enzymes.
iii. Serology test including classic Widal test.

Treatment:

i. Drug susceptible typhoid fever – floroquinolones.
ii. Ceftriaxone, cefotaxime, and (oral) cefixime are effective for treatment of MDR enteric fever, including NAR and fluoroquinolone-resistant strains. These agents clear fever in ~1 week, with failure rates of ~5–10%, fecal carriage rates of <3%, and relapse rates of 3–6%. Oral azithromycin results in defervescence in 4–6 days, with rates of relapse and convalescent stool carriage of <3%.

Reference:

1. Harisson's Principle of Internal Medicine, 17 th edition.

Fever - The mechanism

In the present of pyrogens in our circulation, our hypothalamus set up the new set point. The concept is similar to air-conditioner. When our room temperature has equilibrated with the temperature of the room, let's say 20 degree Celsius, then we increase the temperature to 25 degree Celsius, some changes occur in order increase the temperature. The same thing goes to our body, but the changes are different. The changes include vasoconstrictions of peripheral blood vessels to prevent heat loss (because we need to increase the temperature). This change make me feels cold due to the reduced in blood supply in peripheral area. Cold condition lead to shivering process that lead to increase in heat production. This process continues until the new set point is achieved. When there is changes in set point, the condition would be changed. Lets say the new set of point is 37 degree Celsius instead of 39 degree Celsius, our body react by causing vasodilatation of peripheral blood vessels. Changes happen can lead to sweating as well so that the heat loss is enhanced. The causes of decreased in set point may be related to the treatment such as paracetamol intake or antibiotics that kill the microb that became source of pyrogens.

Reference:

Harisson's Principle of Internal Medicine, 17 th edition.

Chikungunya Virus Infection

Origin: Africa

Vector: Aedes aegypti or A. Albopictus

Incubation period: 2 – 3 days.

Clinical manifestations:

Fever and severe arthralgia and accompanied by several constitutionals symptoms such as photophobia, conjunctival injection, headache, anorexia, nausea and abdominal pain. Rash is also common and most intense in trunk and limb and may desquamate. The appearance of rash often occurs at the outset or several days into the illness. Its development coincides with defervescence, which takes place around day 2 or day 3 of disease. Other symptoms include migratory poly-arthritis that affects small joints of the hand, wrist, feet and ankle with lesser involvement of the larger joints. Some patient may develop leukopenia. There may be an elevated level of AST and C-protein, and mild thrombocytopenia. Some older patient may experience joint pain, stiffness, and effusion for several years; this persistence may be especially common in HLA-B27 patients. Recovery may take weeks.

Reference:

Harisson's Principle of Internal Medicine, 17 th edition.