Senin, 06 September 2010

Common Cold

Common cold itu apa ya?
adalah suatu penyakit infeksi viral(disebabkan oleh virus) di dalam hidung.Penyakit ini bisa melibatkan area sinus,telianga dan pipa bronkus(bronchial tube).
  • Gejala yang ditunjukkan biasanya : bersin2, ingus meleleh(meler), hidung gatal, nyeri tenggorokan, nyeri kepala (tidak berat), demam, menggigil, merasa tidak enak badan, dan serak.
  • Penyakit bisa diderita selama 1 minggu, atau jika ringan bisa hanya 2-3 hari.Kalau yang lebih berat bisa sampai 2 minggu.
  • Common Cold adalah penyakit yang lebih ringan daripada influenza. influenza memiliki tipe seperti :demam, nyeri otot, dan batuk yang lebih berat. bagaimanapun influenza yang ringan hampir sama dengan common cold.
  • Pada orang dewasa dalam setahun bisa memiliki rata2 terserang 2-3 kali, kalau anak2 6-10 kali, tergantung pada umur dan paparannya.
  • Pada anak2 sumber virusnya adalah pada hidungnya.
  • Terdapat lebih dari 100 jenis virus common cold, tetapi yang tersering menyerang adalah rinovirus, setengah dari semua kejadian common cold diperkirakan oleh virus ini.
Virus2 ini hanya bisa memperbanyak diri didalam sel yang hidup. Pada lingkungan diluar sel virus tidak dapat berkembang biak. Tapi bagaimanapun virus yang ada dilingkungan(diluar sel hidup) bisa menyebabkan sakit jika terjadi kontak dengan bagian dalam hidung.
virus2 ini hanya bisa hidup dalam hidung manusia dan simpanse serta hewan primata yang lebih tinggi.


Gambar Hidung(mu)

dalam hidung ada struktur disebut turbinate yang berperan menjebak partikel yang masuk melalui lubang hidung. Material/partikel yang terjebak seperti gambar dibawah akan dipindahkan kebagian belakang hidung hingga mencapai adenoid oleh mekanismme rambut getar dalam jangka waktu 10-15 menit. Nah virus2 penyebab common cold ini dipercaya mengikuti mekanisme diatas untuk mencapai adenoid dan berkembang biak di sel2 adenoid setelah sebelumnya nempel2 di permukaan sel-nya.


















Bagaimana infeksi virus tersebut muncul?

Virus mencapai ujung hidung kita dari kontak hidung kita dengan benda2 disekitar kita yang sempat singgah mencapai hidung,(misal:pada saat ngupil, kita ga tau kalau tangan kita sebelumnya salaman sama orang yang menderita common cold).Infeksi bisa terjadi pada saat kita terkena butiran-butiran cairan "halus" bersin/batuk orang di sekitar kita, dll pokoknya mencapai hidunglah.
Nih gambarnya





Virus awalnya nempel dulu di sel adenoid, lalu melakukan penetrasi ke dalam sel....akhirnya multiplikasi/berkembang biaklah dia sehingga mengakibatkan kematian sel host(sel inang). Sel rusak pecah terkoyak(hehehe...dramatis) lalu melepaskan virus2 dalam jumlah banyak keluar sel. Hal ini berlangsung selama kurang lebih 8 - 12 jam yang sering disebut masa inkubasi.
Tidak butuh banyak virus untuk bisa menginfeksi kita pada kasus ini cukup dengan kisaran 1-30 partikel virus sudah bisa membuat kita terserang sakit.
Gejala puncak penyakit berkisar antara 36 -72 jam.
Apa penyebab munculnya gejala?
Sebenarnya virus dari penyakit common cold ini hanya menyerang sedikit area di dalam hidung
. Lihat saja area yang terkena pada gambar sebelah kanan ini. Cuma area yang ditunjuk saja yang terinfeksi, sedangkan yang sekitarnya sehat wal'afiat. Kerusakan membran yang ditimbulkan juga ringan. Gejala yang ditimbulkan oleh common cold ini murni adalah hasil karya dari mekanisme pertahanan tubuh kita sendiri..hehehehe ironis bukan? tapi seperti itulah tubuh bekerja hampir pada setiap penyakit yang mendera diri kita. Ketika sel hidung terinfeksi atau terpapar oleh partikel2 virus tersebut segera tubuh merespon dengan mengaktivasi sistem kekebalan tubuh kita dan beberapa refleks sistem saraf.
Sistem imun kita memiliki substansi alamiah yang disebut mediator inflamasi dimana mediator ini memiliki banyak variasi. Mediator inflamasi ini melindungi tubuh dari infeksi dan kejadian yang membahayakan tubuh lainnya. Beberapa mediator inflamasi terlepas pada saat virus menempel pada sel hidung. Nama-nama mediator inflamasi yang terlibat dalam penyakit common cold adalah sebagai berikut: Histamin, interleukin, kinins, dan prostaglandin. Ketika diaktivasi oleh virus penyakit common cold maka mediator inflamasi menyebabkan pembuluh darah mengalami dilatasi dan merenggangkan kerapatan jaringan pembuluh darah(leakage) dan juga sekresi kelenjar mukus. Mediator inflamasi juga menyebabkan aktifnya refleks bersin dan batuk dan menstimulasi serabut saraf nyeri. Nah kejadian-kejadian diatas itulah yang menuntun pada gejala-gejala common cold.

Oke untuk treatmentnya gua malas nerjemahin hehehe....pikir sendiri ya

Cold Treatments That Are Effective and Safe

Antihistamines

Histamine

Histamine is a natural substance, one of the important inflammatory mediators produced in certain cells in the body. (20)

When introduced into the nose, histamine causes dilatation and leakage of blood vessels. (20) Histamine is also a powerful stimulant of the sneeze reflex. These effects of histamine cause sneezing, coughing, runny nose, and stopped up nose during colds. Histamine may also have a role in causing coughs, but this is less certain.

Rx pic Antihistamines


There are two classes of antihistamines, the older ("first generation", "sedating") and the newer ("second generation", "non-sedating") classes. (20) The older class of antihistamines is effective for treating colds.

Antihistamines work by preventing histamine from attaching to a cellular receptor, H1. Attachment to this receptor is necessary for histamine activity to occur. (20) The first generation antihistamines also block the activity of a part of the nervous system, the parasympathetic system, that stimulates mucus glands secretion.

Early studies of the first generation antihistamines for the treatment of colds gave negative results because of inadequate precision in recording of cold symptoms. The results of these studies are now known to be incorrect.

Recent studies of first generation antihistamines for treatment of colds employed careful recording of individual cold symptoms on a day-by-day basis. (21-23) These studies showed that first generation antihistamines are quite effective in reducing the sneezing and runny nose of colds. Measured nasal weights were also reduced. One of the antihistamines tested, brompheniramine, reduced the frequency and severity of cough. (23)

The major side effect of first generation antihistamines is drowsiness, which may be severe in some people. (20) Alcohol, sedatives, and tranquilizers increase the drowsiness associated with first generation antihistamines. Also, these antihistamines may cause difficulty in urination in men who have enlargement of the prostate gland and make glaucoma worse in people who have this eye problem.

Antihistamines shown to be effective in recent years in double blind, randomized, controlled clinical trials include brompheniramine, chlorpheniramine, and clemastine. (21-23) Other first generation antihistamines have received various degrees of testing for treatment of the common cold. The duration of activity varies among the different first generation antihistamines, and sustained-release preparations are available for some.

The newer (non-sedating) antihistamines do not appear to have the same degree of effectiveness for treating the sneezing and nasal discharge of colds. (24)

Rx pic Nonsteroidal Antiinflammatory Drugs (NSAIDs)

Nonsteroidal antiinflammatory drugs, such as ibuprofen and naproxen, are effective in treating inflammation, pain, and fever. (25) A major action of NSAIDs is to block the production of certain natural inflammatory mediators called "prostaglandins."

NSAIDs have been used in medical practice to treat general symptoms of a cold such as feverishness, chilliness, muscle ache, and not feeling well in general. (25) More recently, there has been interest in the use of NSAIDs to treat other cold symptoms, especially cough. (26-28) However, only a few clinical trials have been published on the use of NSAIDs for treating colds.(28-30)

The major side effect of NSAIDs is irritation of the gastrointestinal tract. (25) In some people, this can lead to gastrointestinal ulceration and bleeding. NSAIDs may also prolong bleeding and reduce kidney function.

Rx pic Decongestants

Decongestants, such as pseudoephedrine, are in the category of "alpha-adrenergic agonists." (31) These drugs open the nasal passages by shrinking blood vessels in the mucus membrane of the nose, which is the primary cause of the nasal obstruction of colds.

Decongestants may be taken by mouth or applied directly on the nasal mucus membrane in the form of nose drops and sprays. (31)

Decongestant nose drops and sprays have rapid and powerful action in relieving nasal obstruction. (31) When the decongestant effect of the drug wears off, nasal obstruction rapidly returns. Nasal decongestants also burn and irritate the throat.

Decongestants taken by mouth have less powerful and immediate activity but cause less problem with the cycles of recurrent nasal obstruction than topical preparations. (31)

Oral decongestants may produce rapid heart rate, blood pressure elevation, and nervous stimulation. (31) However, when taken in recommended doses, oral decongestants have been shown to be safe, even in patients with hypertension controlled on treatment. (32) When applied directly to the mucus membrane of the nose, decongestants tend to lose their effectiveness over time and result in "rebound" obstruction and mucosal damage. (31)

Rx pic Anticholinergics

Anticholinergics are a class of drugs that block the action of the parasympathetic nervous system on mucus gland secretion, thereby reducing nasal discharge. (33) In this, they have similar activity to first generation antihistamines.

Anticholinergics differ from antihistamines in not having activity against histamine. Because of this, they are less effective in treating sneezing. (33)

Anticholinergic nasal sprays were found to reduce nasal discharge and measured nasal mucus weights in patients with colds. (34-36)

Anticholinergics may cause difficulty in urination in men with prostate disease and worsen the eye problem of glaucoma. (33)

Rx pic Cough Suppressants

Cough suppressants are natural narcotics, like codeine, and synthetic narcotics, like dextromethorphan (DM). (37)

Cough suppressants act on the brain to depress the cough reflex center. (37) Their effectiveness in patients with chronic cough has been demonstrated in controlled trials but there is little published information on their effectiveness in coughs associated with colds. (38)

Cough suppressants can produce gastrointestinal discomfort but otherwise have few side effects. (37)

Cough suppressants should not be used in patients with lung diseases where cough may be ineffective and secretions retained in the lung.

In normal healthy people with good cough reflexes, cough suppressants are safe

1 komentar:

  1. boleh tw darimana sumber ini berasal?saya sangat butuh untk bahan skripsi saya,,

    BalasHapus