Aseptic Techniques And Intestinal Obstruction

Aseptic Techniques (procedures) • Definition • Aseptic technique is a set of specific practices and procedures performed under carefully controlled conditions with the goal of minimizing contamination by pathogens.

Aseptic Techniques • Prerequisite Knowledge •

Principles of asepsis

•

Surgical scrub

Aseptic Techniques • Principles of aseptic technique • Aseptic: The complete absence of lining microorganisms. • Methods to achieve sterility or asepsis: • Chemical methods (e.g. gas sterilization) • Physical methods (e.g. autoclaving)

Aseptic Techniques • Aseptic technique is based on the fundamental principle that the infection is introduced into the body from the outside. • Therefore, perform all procedures using a method that prevents the introduction of bacteria into a surgical wound.

Aseptic Techniques

• Operating Room • The operating room (OR) should provide an environment that is free of bacterial contamination as possible. • The minimum size recommended for an OR is usually 20 by 20 feet, which allow space for: • Gowning of the operative team • Draping the patient • And movement of the other personnel, • Without contaminating of sterile areas

Aseptic Techniques • Operating Room • The concept of separating clean traffic to dirty traffic is theoretically sound but has not been shown to lower wound infection rates. • Studies suggest that the redispersal of bacteria from the OR floor into the air is very low. • Appropriate ventilation rapidly clears bacteria from the air, and the degree of floor contamination should not increase infection rate.

Aseptic Techniques

• Operating Room • The very low concentrations of airborne particulate matter and bacterial in most OR are achieved by changing room air 20 to 25 time each hour and passing inflow air through a high-efficiency particulate air (HEPA) which efficiently remove bacteria and fungi but not virus. • The pattern of air inflow is designed to decreased turbulence at the operating table and prevent entrapment of air from periphery.

Aseptic Techniques

• Operating Room • All OR doors should remain closed except. • The pressure in the OR should be positive relative. • Organisms recovered from the air often are not those that cause wound infection. • The primary sources of perioperative infection is the patients and the secondary sources are the OR team.

Aseptic Techniques • Patients • Is the most important sources of contamination in the OR. • Infection that develop from operations classified as clean-contaminated, contaminated, or dirty are primarily caused by bacteria already present in the operative field.

Aseptic Techniques • Patients • Wound infections that occur in clean operations are often caused by staphylococci or other bacteria form a source in the patient such as the skin or nares. Preparation of the patient’s skin before an incision is one of the most important methods of decreasing infection. •

Aseptic Techniques • Patients • It is effective to have the shower with antibacterial preparation the night before elective procedures. • Hair removal should be employed only when the hair may interfere with the performance of the procedure. • Shaving the patient with razor the night before operation has been associated with a relative high wound infection rate.

Aseptic Techniques

• Patients • The risk of infection is decreased by shaving the patient in the operating OP immediately before the procedure or in the setting by using a depilatory cream or electric clippers. • The most commonly used antimicrobial agents for intact antisepsis are iodophors (e.g. Betadine).

Aseptic Techniques • Patients • The most commonly accepted technique in cleansing the patient’s skin is to begin with the area where the incision is to be made and to consider this as the cleanest portion of the area of operation. • The contaminated sponge stick should never be returned to the cleansing solution.

Aseptic Techniques

• 1. The procedure must be done in a sterile field from which all bacteria have been excluded, if possible. • The inadvertent use of unsterile items may introduce contaminants into the wound. • Items of uncertain sterility must be considered unsterile. • Any item that falls on the floor or into any area of questionable cleanliness must be considered unsterile.

Aseptic Techniques • The circulating nurse should check the package integrity, the expiration date, and the chemical process indicator before dispensing a sterile item.

•

2. Gown worn by the surgical team are considered sterile at the front, from chest to the level of the sterile field. • The sleeves are also considered sterile from to inches above the elbow to the stockinet cuff. • The cuff should be considered unsterile because it tends to collect moistures and is not an effective bacterial barrier. • Therefore, the sleeve cuffs should always be covered by sterile gloves.

Aseptic Techniques • Other areas of gown that should be considered unsterile are the neck, shoulders, areas under the arms, and back. • These areas may become contaminated by perspiration or by collar and shoulder surfaces rubbing together during head and neck movement. • The back of the gown is not sterile it cannot be observed by the scrubbed person and protected from contamination.

Aseptic Techniques

• 3. Sterile drapes are used to create sterile field. Only the top surface of the a draped table is considered sterile. • Although a bacterial barrier may be draped over the side of a table, the sides cannot be considered sterile. • Any item that extends beyond the sterile boundary is considered contaminated and cannot brought back onto the sterile field.

Aseptic Techniques • A contaminated item must be lifted clear of the operative field without contacting the sterile surface and must be dropped with minimum handling to an unsterile person, area, or receptacle.

Aseptic Techniques

• 4. Items should be dispensed to a sterile field by

methods that preserve the sterility of the items and the integrity of the sterile field.

• After a sterile package or container is opened, the edges are considered unsterile. • The sterile and unsterile boundaries are often intangible.

►A 1cm safety margin is usually

considered standard on package

wrappers.

► Whereas, the sterile boundary on a wrapper used to drape a table is at the table edges

Aseptic Techniques

• ►On peel-back packages, the inner edge of the heat seal is the line of demarcation.)

• ►the edge of bottle cap is considered contaminated once the cap has been removed from the bottle)

• ►The sterility of the contents replaced on the bottle.)

cannot be ensured if the cap is

Aseptic Techniques

• 5. Motions of the surgical team are from sterile to sterile areas and from unsterile to unsterile areas. • Scrubbed person stay close to the sterile field. • If they change positions, they turn face-to-face or backto-back while maintaining a safe distance between. • Accidental contamination is a threat to any scrubbed person who wanders into traffic pathway or out of the clean area

Aseptic Techniques • Approach sterile areas facing them and never walk between two sterile fields. • Keeping sterile areas in view during movement around the area. • All preoperative personal must maintain a vigilant watch over sterile areas and point out any contamination immediately.

Aseptic Techniques • 6. Whether a sterile barrier is permeated, it must be considered contaminated. •

This principle applies to packaging materials as well as to draping and gowning materials.

• Obvious contamination occurs from direct contact between sterile and unsterile objects. • Other less apparent modes of contamination are

Aseptic Techniques

• Obvious contamination occurs from direct contact between sterile and unsterile objects. • Other less apparent modes of contamination are the:

*filtration of airborn microorganisms through materials. • * The passage of liquid materials . • * The undetected perforations in materials.

Aseptic Techniques • When moisture soaks through drape, gown, or package, the items must be considered contaminated. • 7. Sterile fields should be prepared as close as possible to the scheduled time of use.

Aseptic Techniques

• Patient Position • Patient position should:

• Ensure optimum exposure and access of the operative site.

• • •

Sustain body alignment. Maximize circulatory and respiratory function Not compromise neuromuscular structure

Aseptic Techniques

• Surgeon • Operating Room Attire • Comfortable closed in shoes (preferably operating room dedicated) • Eat breakfast , and use restroom before the session begins! • No jewellery or nail polish • Short, clean nails

Aseptic Techniques

• Surgeon • Operating Room Attire • Protective eyewear • Hat, hair tucked in • Mask facing out, tied securely. • ►► Now Ready for operating room

Aseptic Techniques

• Surgeon • Review of surgical scrub *Scrub time: 5 min for the first scrub of the day, and 3 min for each subsequent scrub.

* Hand and forearms are to be held out from scrub clothes * * * * * *

Hand to be at higher level than elbows at all the time. Scrub solution is applied to hands. Each nail is cleaned under running water with nail stick. Each nail is scrubbed against palm of opposite hand. Each finger is then scrubbed in all 4 sides. Back of the hand and palm is scrubbed from base of fingers to wrist

Aseptic Techniques • Surgeon • Review of surgical scrub * Small overlapping circles are used to scrub from wrist to 2 cm above elbow. * Hand and forearms are rinsed from finger-tip to elbow.

Aseptic Techniques • Hand drying • Drying towel is lifted up away from the sterile field without dripping water into that field. • Bent forward at the waist, fingers and hand are dried thoroughly, then the same part of towel is used to dry remainder of forearm • The other end of the towel is then used to dry the other hand and forearm.

Aseptic Techniques

• Gowning • The sterile gown is lifted out of it sterile wrapper without contamination. • The individual then moves into an area where the gown may be opened without contamination of gown. • The gown is held away from the body and unfolded so that the inside is toward the wearer.

• Gowning • The hands are slipped into the gown while keeping them away from the body at and shoulder level • The hand are advanced up the sleeves of the gown to the proximal end of the cuffs. • “”Gloving is performed by the closed or opened method. • The surgeon then hands the sterile right tab of the gown the scrub nurse, turns left 280º and then takes back this tab. He/Her then ties this to the other sterile tab to wrap the gown.

Aseptic Techniques

• Gloving • Closed method • In this technique the scrubbed nurse assists the scrubbed individual with gloving. • Opened method • No assist

Aseptic Techniques • Removal of dirty gown and gloves • This is recommended to prevent contact with the soiled outer layer of gloves and gown and mask. • The waist tie is untied by the surgeon. • The surgeon turn away from the circulating nurse to allow him/her to undo the back closure of the gown. • The surgeon then grasps a shoulder of the gown and pulls it inside out off one gloved arm, pulls that sleeve off leaving the glove on, but with the cuff now everted.

Aseptic Techniques • Removal of dirty gown and gloves • This step is repeated with the other arm. • The gown is pulled off completely, held away from the body, and placed into the appropriated linen container. • The gloved finger of one hand are placed under the eveted cuff of the cotrolateral glove. The glove is pulled off and inverted at the same time. • The everterd cuff on the remaining glove is then grasped the bare free fingers of the other hand and is pulled off in the same way.

Aseptic Techniques • Removal of dirty gown and gloves • The surgeon then goes back to the scrub area and removes his/her mask, taking care to touch only the ties at the back. (A new mask should be worn for each case). • The arms should then be watched carefully.

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TERMINOLOGY

• Antimicrobial - An agent or action that kills or inhibits the growth of micro-organisms. • Antiseptic - A chemical agent that is applied topically to inhibit the growth of micro-organisms. • Asepsis - Prevention of microbial contamination of living tissues or sterile materials by excluding, removing or killing micro-organisms. • Autoclave - A steam sterilizer consisting of a metal chamber constructed to withstand the pressure that is required to raise the temperature of steam to the level required for sterilization. Early models were termed "autoclaves" because they were fitted with a self-closing door.

• Bactericide - A chemical or physical agent that kills vegetative (non-spore forming) bacteria. • Bacteriostat - An agent that prevents multiplication of bacteria. • Commensals - Non-pathogenic micro-organisms that are living and reproducing as human or animal parasites. • Contamination - Introduction of micro-organisms to sterile articles, materials or tissues.

• Disinfectant - An agent that is intended to kill or remove pathogenic micro-organisms, with the exception of bacterial spores. • Pasteurization - A process that kills nonspore-forming micro-organisms by hot water or steam at 65-100oC. • Pathogenic - A species that is capable of causing disease micro-organism in a susceptible host. • Sanitization - A process that reduces microbial contamination to a low level by the use of cleaning solutions, hot water or chemical disinfectants

• Sterilant - An agent that kills all types of microorganisms. • Sterile - Free from micro-organisms. • Sterilization - The complete destruction of microorganisms

INTESTINAL OBSTRUCTION • Definition • Is a partial or complete blockage of the bowel (small or large intestine) that prevent the faces and gas from passing distally. • Frequency • Among patients who are admitted to the hospital for severe abdominal pain, 20% have an intestinal obstruction.

INTESTINAL OBSTRUCTION • Frequency • Bowel obstruction can affect individuals of any age. • Different conditions occur at higher rates in certain age groups • ►Children under the age of two, for example, are more likely to present with intussusceptions or congenital defects •

►Elderly patients, on the other hand, have a higher rate of colon cancer.

INTESTINAL OBSTRUCTION • Morbidity and mortality rates • The mortality rate of small bowel obstruction ranges from 2% for a simple obstruction to 25% for a strangulation obstruction that compromises the blood supply and is treated after a lapse of 36 hours. • Large bowel obstruction carries a mortality rate of 2% for volvulus to 40% if part of the bowel is gangrenous.

INTESTINAL OBSTRUCTION

• Etiology There are two types of intestinal obstructions, mechanical and non-mechanical, called paralytic ileus. Mechanical obstructions occur because the bowel is physically blocked. Unlike mechanical obstruction, non-mechanical obstruction, occurs because peristalsis stops.

INTESTINAL OBSTRUCTION

• Etiology • Mechanical Obstruction • Three types of abnormalities may produce mechanical obstruction

•

I) Obstruction of intestinal lumen may be caused by several kinds of diseases, such as:

•

► Intussusception :

• Is an invagination of the bowel lumen, with invaginated portion (the intussusceptum) passing distally into the ensheathing outer portion (the intussuscipiens) by peristalsis.

INTESTINAL OBSTRUCTION

• Etiology • Mechanical Obstruction • ► Intussusception • Unrelieved intussusception can occlude the blood supply of the intussusceptum. • In adults, intussusception is usually caused by an abnormality of the bowel wall, such as tumor or Meckel’s diverticulum.

INTESTINAL OBSTRUCTION

• Etiology • Mechanical Obstruction • ► Intussusception • In infants and children, intussusception may occur without apparent anatomic cause

• ►

Large gallstone

• Can enter the intestinal lumen via a cholecystoenteric fistula, can cause obstruction to produce to produce a rare condition called gall stone ileus.

INTESTINAL OBSTRUCTION

• Etiology • Mechanical Obstruction • ►Feces, meconium, or bezoars may obstruct the intestine. • Bezoars occur more frequently in children, the mentally retarded, and the toothless, and in patients after gastrectomy.

INTESTINAL OBSTRUCTION

• Etiology • Mechanical Obstruction • 2) Intrinsic bowel lesion • Producing intestinal obstruction are often congenital such as: • Artesia, • Stenosis • Duplication • They occur most commonly in infant and children.

INTESTINAL OBSTRUCTION

• Etiology • Mechanical Obstruction • 2) Intrinsic bowel lesion • Neoplasm: carcinoma of the sigmoid colon • Inflammation: Chrohn’s disease

• 3) Lesions extrinsic to the bowel cause intestinal obstruction.

• ► Adhesion of the intestine by adhesions from previous operations or inflammation is the leading cause of small intestinal obstruction.

INTESTINAL OBSTRUCTION

• Etiology • Mechanical Obstruction • ► External hernias are the second most common cause of mechanical small intestinal obstruction.

• ► Internal hernia due to congenital abnormalities of the mesentery or to surgical defects in the mesentery cause bowel obstruction.

• ► Extrinsic masses such as: such neoplasms and abscesses may cause mechanical bowel obstruction..

INTESTINAL OBSTRUCTION

• Etiology • Mechanical Obstruction • ► A volvulus • Is an extrinsic abnormality in which a portion of the alimentary canal rotates or twists about itself. • The twist usually involves the blood supply of the twisted portion of the bowel.

INTESTINAL OBSTRUCTION

• Etiology • Mechanical Obstruction • ► A volvulus • A volvulus usually accompanies an underlying abnormality: midgut volvulus is caused by mesenteric abnormality of malrotation. • Cecal volvulus occurs when the cecum or right colon is on e mesentery rather than being retroperitoneal.

INTESTINAL OBSTRUCTION • Etiology • Mechanical Obstruction

• ► A volvulus • Sigmoid volvulus develops when the sigmoid abnormally long or redundant. • Another type of volvulus occurs when adhesion fix the intestinal to a point that acts as a pivot for the volvulus. • The most common causes of intestinal obstruction in adults are adhesions, usually from previous operations (hernias, and neoplasms.)

INTESTINAL OBSTRUCTION • Etiology • Mechanical Obstruction

• ► A volvulus • Neoplasms are the most common cause of colon obstruction.

• Etiology • Paralytic Ileus (or non-mechanical obstruction) • It is a common disorder, occurs to some extent in most patients undergoing abdominal operations. • Several neural, humoral, and metabolic factors cause this abnormality; such as:

• ► Intestinointestinal reflex, result from prolonged intestinal distention.

(*Distenstion of other organs, such as the ureter, can inhibit intestinal motility. *Spine fracture, retropeitoneal hemosshrage, or trauma or trauma can also produce paralytic’s ileus)

INTESTINAL OBSTRUCTION • Etiology • Paralytic Ileus (or non-mechanical obstruction)

►Clinically, peritonitis causes paralytic ileus. ► Electrolyte imbalance, particularly hypokalemia, contribute to paralytic ileus by interfering with the normal ionic movements during smooth muscle contraction.

► Finally, ischemia of the intestine rapidly inhibits motility.

INTESTINAL OBSTRUCTION • Etiology

• Idiopathic Intestinal Pseudo-Obstruction (IIPO). • IIPO is a chronic illness characterized by symptoms of recurrent intestinal obstruction without demonstrable mechanical occlusion of bowel. • The patients with this disease have: • impaired motor response to intestinal distension. • Duodenal and colonic slow waves may be normal. • Some patients have aperistalsis of the esophagus

INTESTINAL OBSTRUCTION • Etiology

• Idiopathic Intestinal Pseudo-Obstruction (IIPO). • In IIPO, the heredity plays a role in this disorder. • • • • • •

The symptom IIPO include Cramping abdominal pain Vomiting Distension Diarrhea Steatorrea.

INTESTINAL OBSTRUCTION • Etiology

• Idiopathic Intestinal Pseudo-Obstruction (IIPO). • Physical examination reveals abdominal distension. • IIPO is distinguished from mechanical intestinal obstruction by the absence of the radiological findings of mechanical obstruction. • Surgery treatment for IIPO should be avoid. • Intravenous hyperalimentation may be help manage these patients.

INTESTINAL OBSTRUCTION • Pathogenesis • Intestinal Obstruction • Mechanical obstruction of the intestine causes accumulation of the fluid and gas proximal to the obstruction, producing distention of the intestine. • Ingested fluid, digestive secretions and intestinal gas initiate the distension. • Large volume of saliva, gastric secretion, bile, and pancreatic juice enter the gut daily. • The stomach has a very small capacity for absorbing fluid.

INTESTINAL OBSTRUCTION

• Pathogenesis • Intestinal Obstruction • Obstruction of the bowel leads to proximal dilatation of the intestine due to accumulation of GI secretions and swallowed air. • This bowel dilatation stimulates cell secretory activity resulting in more fluid accumulation. • This leads to increased peristalsis both above and below the obstruction with frequent loose stools and flatus early in its course

• Pathogenesis • Intestinal Obstruction • Vomiting occurs if the level of obstruction is proximal. Increasing bowel distention leads to increased intraluminal pressures. • This can cause compression of mucosal lymphatics leading to bowel wall lymphedema. With even higher intraluminal hydrostatic pressures, increased hydrostatic pressure in the capillary beds results in massive third spacing of fluid, electrolytes, and proteins into the intestinal lumen. • The fluid loss and dehydration that ensue may be severe and contribute to increased morbidity and mortality.

• Pathogenesis • Intestinal Obstruction • Strangulated bowels are most commonly associated with adhesions and occur when a loop of distended bowel twists on its mesenteric pedicle

• Pathogenesis • Intestinal Obstruction • Bacteria in the gut proliferate proximal to the obstruction. • Microvascular changes in the bowel wall allow bacterial translocation to the mesenteric lymph nodes. ►►► ►Systemic toxicity, dehydratation and electrolytes abnormalities. • The arterial occlusion leads to bowel ischemia and necrosis. If left untreated, this progresses to perforation, peritonitis, and fecal soilage of peritoneal cavity if left untreated ► death.

• The pathophysiology of acute colonic pseudo-obstruction (ACPO) is not clear, but it is thought to result from an autonomic imbalance, which results from decreased parasympathetic tone or excessive sympathetic output. • ACPO usually occurs in the setting of a wide range of medical or surgical illnesses. • If untreated, colonic ischemia or perforation can occur.

• This syndrome is characterized by a loss of peristalsis and results in the accumulation of gas and fluid in the colon. The right colon and cecum are most commonly involved. • The risk of perforation for ACPO ranges from 3-15%. The mortality rate is 15% with early care; this increases to 36% if colonic ischemia or perforation develops.

INTESTINAL OBSTRUCTION • • • •

Clinical Small bowel History Abdominal pain (characteristic with most patients)

• Pain, often described as crampy and intermittent, is more prevalent in simple obstruction. • Often, the presentation may provide clues to the approximate location and nature of the obstruction. • Usually, pain that occurs for a shorter duration of time and is colicky and accompanied by bilious vomiting may be more proximal..

• Clinical • Small bowel • History • Pain lasting as many as several days, which is progressive in nature and with abdominal distention, may be typical of a more distal obstruction. • Changes in the character of the pain may indicate the development of a more serious complication (i.e., constant pain of strangulated or ischemic bowel). • Nausea • Vomiting, which is associated more with proximal obstructions • Diarrhea (an early finding)

INTESTINAL OBSTRUCTION • • • •

Clinical Small bowel History Constipation (a late finding) as evidenced by the absence of flatus or bowel movements.

• • Fever and tachycardia - Occur late and may be associated with strangulation. • • Previous abdominal or pelvic surgery, previous radiation therapy, or both (may be part of patient's medical history) • History of malignancy (particularly ovarian and colonic)

• Physical Examination: • Small bowel • Abdominal distention • Duodenal or proximal small bowel has less distention when obstructed than the distal bowel has when obstructed. • Hyperactive bowel sounds occur early as GI contents attempt to overcome the obstruction. • Hypoactive bowel sounds occur late.

• Physical Examination: • Small bowel • Exclude incarcerated hernias of the groin, femoral triangle, and obturator foramina. • Proper genitourinary and pelvic examinations are essential. • Look for the following during rectal examination *Gross or occult blood, which suggests late strangulation or malignancy

*Masses, which suggest obturator hernia

INTESTINAL OBSTRUCTION • Physical Examination: • Small bowel • Check for symptoms commonly believed to be more diagnostic of intestinal ischemia, including the following: Fever (temperature >100°F) Tachycardia (>100 beats/min) Peritoneal signs No reliable way exists to differentiate simple from early strangulated obstruction on physical examination. Serial abdominal examinations are important and may detect changes early.

INTESTINAL OBSTRUCTION • • • •

Differential Diagnosis Small bowel Appendicitis, Acute; Cholangitis ; Cholangitis Cholecystitis and Biliary Colic Cholelithiasis Constipation Diverticular Disease Foreign Bodies, Gastrointestinal Gastroenteritis Inflammatory Bowel Disease

• Differential Diagnosis • Small bowel • Obstruction, Large Bowel Ovarian Torsion Pancreatitis Pediatrics, Appendicitis Pediatrics, Diabetic Ketoacidosis Pediatrics, Gastroenteritis Pediatrics, Intussusception Pelvic Inflammatory Disease Urinary Tract Infection, Female Urinary Tract Infection, Male

• Lab Study • Small bowel • 1) Essential laboratory tests • Serum chemistries: Results are usually normal or mildly elevated. • BUN level: If the BUN level is increased, this may indicate decreased volume state (e.g., dehydration). • Creatinine level: Creatinine level elevations may indicate dehydration

• Lab Study • Small bowel • CBC: WBC count may be elevated with a left shift in simple or strangulated obstructions. Increased hematocrit is an indicator of volume state (i.e., dehydration). • Lactate dehydrogenase tests • Urinalysis. • • Type and crossmatch: The patient may require surgical intervention.

• Lab Study • Small bowel • Laboratory tests to exclude biliary or hepatic disease • Phosphate level • Creatine kinase level • Liver panels

• • • •

Small bowel Imaging Studies 1) Plain radiography Obtain plain radiographs first for patients in whom SBO is suspected. • At least 2 views, supine or flat and upright, are required. • Plain radiographs are diagnostically more accurate in cases of simple obstruction; however, diagnostic failure rates of as much as 30% have been reported.

• Small bowel • Imaging Studies • 1) Plain radiography • Dilated small-bowel loops with air fluid levels indicate SBO. • Absent or minimal colonic gas indicates SBO.

• • • •

Small bowel Imaging Studies 2) Enteroclysis Enteroclysis is valuable in detecting the presence of obstruction and in differentiating partial from complete blockages.

• This study is useful when plain radiographic findings are normal in the presence of clinical signs of SBO or if plain radiographic findings are nonspecific

• Small bowel • Imaging Studies • 3) CT scanning • CT scanning is useful in making an early diagnosis of strangulated obstruction. • CT scanning is about 90% sensitive and specific in detecting SBO. • 4) Ultrasonography • Ultrasonography is less costly and less invasive than CT scanning. • It may reliably exclude SBO in as many as 89% of patients. • Specificity is reportedly 100%.

• Treatment • Emergency Department Care • Initial ED treatment consists: • ► aggressive fluid resuscitation, • ► bowel decompression, • ► administration of analgesia and antiemetic as indicated clinically, • ► antibiotics (to cover against gram-negative and gram-positive) • ► and early surgical consultation

INTESTINAL OBSTRUCTION • Large Bowel • Clinical • History 1) Obtain history of bowel movements, flatus, constipation (i.e., no gas or bowel movement), and symptoms. • Major complaints include abdominal distention, nausea, vomiting, and crampy abdominal pain. • Abrupt onset of symptoms makes an acute obstructive event (e.g., cecal or sigmoid volvulus) a more likely diagnosis.

• • • •

Large Bowel Clinical History History of chronic constipation, long-term cathartic use, and straining at stools implies diverticulitis or carcinoma.

• Change in caliber of stools strongly suggests carcinoma. When associated with weight loss, likelihood of carcinoma increases.

• Large Bowel • Clinical • History 2) Colonic lesion development history Right-sided colonic lesions can grow quite large before obstruction occurs because of the large capacity of the right colon and soft stool consistency. Sigmoid colon and rectal tumors cause colonic obstruction much earlier in their development because the colon is narrower and the stool is harder in that area.

• • • • •

Large Bowel Clinical History 3) Large-bowel obstruction prior to perforation Obstruction that dilates the colon causes vague, visceral abdominal cramps. Pain receptors sense distention or vigorous contraction.

• Peritonitis may ensue. • When giving a history of obstipation, patients may state that pants or belts are not fitting properly. • Intervention is necessary to prevent perforation.

• Large Bowel • Clinical • History • 4) Obstruction secondary to intussusception. • • Patients may describe intermittent, crampy abdominal pain that is colicky and relieved by assuming fetal position. • • Weight loss and fatigue are common

• • •

Large Bowel Clinical History

• 5) Obstruction secondary to ACPO • Symptoms are similar to LBO and usually develop over 3-7 days, or less commonly, over 24-48 hours. • Eighty-three percent of patients complain of mild/moderate pain, which is typically diffuse and colicky in nature. • Nausea and vomiting are not predominate complaints. • Fever may be present in the setting of colonic ischemia or perforation

• Large Bowel • Clinical • History • 6) Pneumaturia, mucinuria, or fecaluria may occur when fistulization of the sigmoid colon to the bladder occurs secondary to diverticulitis or cancer.

• Physical Examination • Large bowel • Abdominal distention may be significant in patients with a large-bowel obstruction. •

Bowel sounds may be normal early on but usually become quiet.

• Abdomen is hyperresonant to percussion. • Palpation of the abdomen reveals tenderness. Fever, severe tenderness, and abdominal rigidity are ominous signs that suggest peritonitis secondary to perforation.

• Physical Examination • Large bowel • The cecum is the area most likely to perforate (following the Laplace law). Sigmoid diverticulitis and a perforated sigmoid secondary to carcinoma are clinically difficult to differentiate. • Patients may have guaiac-positive stool if carcinoma is the etiology. • Rectal or lower sigmoidal mass may be palpated on rectal examination. A mass or fullness may be appreciated if a tumor is present in the cecum.

• Differential Diagnosis • Large bowel Abdominal Pain in Elderly Persons Constipation Diverticular Disease Obstruction, Small Bowel

• Lab Studies • Large bowel • Obtain a blood sample for a CBC, electrolyte levels, prothrombin time (PT), and type and crossmatch.

• Emergency Department Care • Initial therapy includes volume resuscitation, appropriate preoperative antibiotics, gastric decompression, and timely surgical consultation.

• Imaging Studies • Large bowel • Obtain an upright chest radiograph and flat and upright abdominal radiographs. • Chest radiographs demonstrate free air if perforation has occurred; abdominal radiographs may be diagnostic of sigmoid or cecal volvulus (ie, kidney bean appearance on the radiograph). • Intramural air is an ominous sign that suggests colonic ischemia

• Imaging Studies • Large bowel • The absence of free air does not exclude perforation (this finding may be absent in half of all perforations). • Additional contrast studies include an enema with watersoluble contrast (i.e., Gastrografin) or CT with intravenous and oral or rectal contrast. • Contrast studies that reveal a column of contrast ending in a "bird’s beak" are suggestive of colonic volvulus

INTESTINAL OBSTRUCTION • Pediatrics, Intussusception

• Background • Intussusception is the telescoping or prolapse of one portion of the bowel into an immediately adjacent segment. • Contrast enema can reduce the intussusception in approximately 75% of cases

INTESTINAL OBSTRUCTION • Pediatrics, Intussusception

• Pathophysiology • Intussusception most commonly occurs at the terminal ileum (i.e., ileocolic). • The telescoping proximal portion of bowel (i.e., intussusceptum) invaginates into the adjacent distal bowel (i.e., intussuscipiens).

INTESTINAL OBSTRUCTION • Pediatrics, Intussusception

• Pathophysiology • The mesentery of the intussusceptum is compressed, and the ensuing swelling of the bowel wall quickly leads to obstruction. • Venous engorgement and ischemia of the intestinal mucosa cause bleeding and an outpouring of mucous, which results in the classic description of red "currant jelly" stool. • Most cases (90%) are idiopathic.

INTESTINAL OBSTRUCTION • Pediatrics, Intussusception

• Mortality/Morbidity • Most patients recover if treated within 24 hours. • Mortality with treatment is 1-3%. If left untreated, this condition is uniformly fatal in 2-5 days. • Recurrence is observed in 3-11% of cases. Most recurrences involve intussusceptions that were reduced with contrast enema.

INTESTINAL OBSTRUCTION • Sex • Overall, the male-to-female ratio is approximately 3:1. • • With advancing age, gender difference becomes marked; in patients older than 4 years, the male-tofemale ratio is 8:1. • Age • Intussusception is most common in infants aged 3-12 months

INTESTINAL OBSTRUCTION • Pediatrics, Intussusception

• Clinical Examination • History • The typical presentation is a previously healthy infant boy aged 6-12 months with sudden onset of colicky abdominal pain with vomiting. •

Paroxysms of pain occur 10-20 minutes apart.

• Initially, loose or watery stools are present concurrent with vomiting and, within 12-24 hours, blood or mucous is passed rectally.

INTESTINAL OBSTRUCTION • Pediatrics, Intussusception

• Clinical Examination • History • Early in the course, the patient appears completely well between the episodes of abdominal pain. • Lethargy may dominate the initial presentation. However, lethargy usually occurs later in the process. • The classic triad of colicky abdominal pain, vomiting, and red currant jelly stools occurs in only 21% of cases

INTESTINAL OBSTRUCTION • Pediatrics, Intussusception • Physical Examination • Usually, the abdomen is soft and nontender early, but it eventually becomes distended and tender. •

A vertically oriented mass may be palpable in the right upper quadrant.

• • Currant jelly stools are observed in only 50% of cases. • Most patients (75%) without obviously bloody stools have stools that test positive for occult blood. • Fever is a late finding and is suggestive of enteric sepsis.