01 Anatomi Dan Fisiologi GIT

Consists of the:

Mouth

Oesophagus

Stomach

Small Bowel

Large Bowel

Anus

About 5-7 meters long, and 7-10m2 in surface

Consists of three main parts:

Duodenum

Jejunum

Ileum

1. Food is being broken down

2. Absorption of nutrients and majority of water

Absorption of nutrients:Fats: upper part of IleumCarbohydrates & proteins: Ileum & JejunumSalts: Ileum (& partially Colon)Vitamin B12: terminal Ileum

About 8 litres produced daily,And around 7 litres absorbedSalvia: 1 litreGastric juice: 2 litrePancreatic juice: 1 litreBile: 1 litreIntestinal juices: 3 litre

app. 4 hours

Is 1-2 meters long, Divided into several sections:

Ascending

Transverse

Descending

Sigmoid

Rectum

Anus

Principal functions: Absorption of water, bile salts and electrolytes Reservoir for faeces until convenient to evacuate from anus

12-18 hours

ILEOSTOMY

Ileostomy

Open, Transparent bag

Permanent ileostomy end ileostomy

Temporary ileostomies end ileostomy

loop ileostomy

Newly operatedSutures are pulling the skinSeparation (beginning)Skin slightly macerated Post-op oedema

” Perfect” ileostomyNormal colour and sizeNice round shapeSurrounding skin normal

Oral: 3-4 cm (everted)Anal: skin level

Oedema

Normally 1500-2000 mL fluid /day enters the colon from the ileum

ILEOSTOMY OUTPUT : 1. POD 1 – 3 : effluent is bilious & liquid 2. POD 3/5 : output stabilizes or slightly3. – 6-8 weeks : steadily until a steady state

* 200 – 700 mL/day High stomal output in the perioperative period is

managed by aggressive rehydration & replacement of depleted electrolytes

4 – 6 month post op : - effluent volume varies little - consistency is porridge-like :

yellow brown colour & food particles (+)

Ileostomy effluent : 90% water Correlation between body mass & output :

* 40 kg individu ~ output 300-400 mL/day* 80 kg individu ~ output 800 mL/day( Hill GL, et al )

Ileostomy adaptation : - slowing small bowel transit time

Gastrointestinal Transit After ProctocolectomyGroup (mean ± SD)------ -----------------------------Control Ileostomy

Parameter (min) ( n = 8 ) ( n = 5 ) p value----------------------------------------------------Gastric emptying 120±22 109±10 NS

Small bowel transit 243±32 348±12 <0.01----------------------------------------------------

Soper NJ et al. Gastrointestinal transit after proctocolectomy with ileal pouch-anal anastomosis or ileostomy, J Surg Res 46:300, 1989 from Taylor WE, Pemberton JH, Stoma Physiology in Cataldo PA, MacKeigan, Intestinal Stomas,Principles,Techniques, and Management, 2004

Water intake : - no role in determining ileostomy output

Dehydration : - output, - thicker consistency

Fasting : output 50 – 100 mL/day Elemental diet :

output & [ digestive enzymes & bile salt ] High fat content :

increase output to 20% > baseline Increases in fiber content > 16g/day :

: - output by 20-25%, - stool frequency & flatus

diet Na volume of stomal output Grape & Fruit juices : stool’s wet weight Majority of patients :

- maintaining or gaining weight- tolerance of most food types

Normal nutrition is the goal As terminal ileal resections are < 100 cm, there

are few nutritional consequences

Taylor WE, Pemberton JH, Stoma Physiology in Cataldo PA, MacKeigan, Intestinal Stomas,Principles,Techniques, and Management, 2004

Na lost in ileostomy effluent ± 60 mEq/day;via normal person’s stool : 2-10 mEq/day

Symptomatic salt depletion is rare :urine output & Na excretion are decreased( enhanced renal conservation of salt & water )

Ileal Na loss is normally overcome w standard diet

However, onset of volume depletion is rapid if high ileostomy output developed

Terminal ileum is important for water & Na resorption

Extent of small bowel resection directly effects the ileostomy adaptation process

Losses of fat & nitrogen > in more extensive bowel resection influence water & electrolyte loss

A proximal located loop ileostomy extended ileal resection

Normal individu = ileostomy patient loses 9 mEq K/day

Mature ileostomy excretes ± 1.5 g N daily Cooper et al :

- ileal resection 4 cm : normal body weight, normal fat & water content, reduced total body N & K implying a fat free body mass- ileal resected > 50 cm : total body weight , due to total fat

Extensive ileal resection : Ca & Mg loss

Taylor WE, Pemberton JH, Stoma Physiology in Cataldo PA, MacKeigan, Intestinal Stomas,Principles,Techniques, and Management, 2004

After ileostomy : intermediate in nature between small bowel & colon

80 x organisms in terminal ileum Coliforms > 2500 x than in normal ileal fluid Staphylococci, streptococci & fungi Bacteroides fragilis was rarely found

Urinary stone formation :|- 3-13%- predisposing factors : high output ileostomy & extensive ileal resection- related to dehydration & excess Na losses- 60% uric acid stones - Christie et al : * ileostomy & IPAA patients : urine volume & pH * [ Ca & Oxalat ] * ileostomies’ patients were at increased risk for forming uric acid & calcium stones

Prophylaxis : daily fluid intake & urine output

Taylor WE, Pemberton JH, Stoma Physiology in Cataldo PA, MacKeigan, Intestinal Stomas,Principles,Techniques, and Management, 2004

Gallstone formation :well adapted pts excrete bile acid = normal person

Extensive terminal ileal resection or inflammation :- enterohepatic circulation is disrupted- alters saturation of bile in GB precipitation stone formation

COLOSTOMY

Closed-end bag Colostomy

Open-end bag

Permanent colostomies

sigmoid colostomy

Temporary colostomies sigmoid colostomy a.m. Hartmann

loop transverse colostomy

divided transverse colostomy

Rectal amputation

+ sigmoid colostomy

Sigmoid colostomy

a.m. Hartmann

Newly operatedSkin looks fineAseptic post-op inflammationPost-op oedema

” Perfect” OstomyNormal colour and sizeNice round shapeSurrounding skin normal

Below the costal angle,usually to the right

1-3 cm above skin level

Diameter 6-10 cm, oval shape

Semi-firm - thin faeces

Relatively large amount of gas

Malodorous faeces

Faeces damaging to the skin

Loop colostomy Divided colostomy

Ability to create a healthy, well functioning, easily manageable colostomy is essential for all abdominal surgeons

A frequent part of emergent colon surgery Almost any abdominal procedure carries some

risk of requiring a colostomy or ileostomy OSTOMY = anastomosis between an endothelially

lined organ & the skin

Cataldo TE, End Sigmoid/Descending Colostomy in Cataldo PA, MacKeigan, Intestinal Stomas,Principles,Techniques, and Management, 2004

Stoma should be free of complication : retraction, stricture & prolaps

Temporary : many are in place or months to years every stoma should be created as if it was the only mode of defecation for life !

To achieve best functional outcome :_ tension free construction- adequate blood supply- minimal tissue manipulation

Stoma

Adhesion area

Area of discolouration

2

The area of discolouration is 25–50% of the total adhesion area

Therefore, the area score = 2

Stoma will frequently be a significantly life altering event

Whenever possible, it is best to have the patient & family well educated prior to surgery

Preoperative evaluation & marking by a qualified ETN will greatly improved patient satisfaction & funtional result

Cataldo TE, End Sigmoid/Descending Colostomy in Cataldo PA, MacKeigan, Intestinal Stomas,Principles,Techniques, and Management, 2004

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