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Abbreviation for conscious, alert, oriented.


chemical formula for calcium oxide.

calcium oxide

A whitish, odourless crystal widely used in industry; it is poorly soluble in water, and reacts with water to form calcium hydroxide (CaOH), a base. It has a melting point of 2614ºC and a boiling point of 2850ºC.
Mucocutaneous and upper airway irritation, burns with oropharyngeal ulceration, abdominal pain, nausea and vomiting.


(ob-struk'shon) [L. obstructio, blockade]
1. Blockage of a structure that prevents it from functioning normally.
2. A thing that impedes; an obstacle.

aortic obstruction

Blockage of the aorta, which prevents the flow of blood.

biliary obstruction

Blockage of the flow of bile from the gallbladder. It is typically caused by gallstones but occasionally from other causes, e.g., cancer, cholangitis, cirrhosis, or parasites.


Biliary obstruction may cause right upper quadrant abdominal pain that radiates to the right flank, nausea, vomiting, jaundice, clay-colored stools, and green or dark urine.

bladder outlet obstruction

Abbreviation: BOO
The inability to pass urine. BOO is caused by prostatic hyperplasia, drug therapy, or urethral injury and may produce bladder pain, urinary tract infection (esp. in elderly men), or kidney failure. See: benign prostatic hyperplasia

central airway obstruction

Compression of the upper airways by a tumor, esp. lung cancer, or a goiter; inhalation of a foreign body into the airway; or narrowing of the trachea by a stricture or tracheomalacia or bronchiomalacia. It is a potentially life-threatening condition that in many cases requires bronchoscopy to clear the airway, often followed by placement of a stent.

chronic airflow obstruction

Abbreviation: CAO
Chronic obstructive pulmonary disease.

foreign body airway obstruction

Blockage of the free passage of air from the mouth and nose to the lungs by any object accidentally inhaled into the trachea, bronchus, or pharynx. Common causes of this type of obstruction are red meat, hard candy, hot dogs, coins, and marbles.
See: Heimlich maneuver

gastric outlet obstruction

Blockage of the flow of food or liquids from the stomach to the duodenum. In children, the cause may be pyloric stenosis or atresia. In adults, ulcers and cancer are frequent causes.

intestinal obstruction

A partial or complete blockage of the lumen of the large or small intestine.


Patients typically complain of colicky abdominal pain, nausea, vomiting (if the obstruction is in the proximal small intestine), or inability to pass gas or stool. Thirst, dizziness, malaise, and other symptoms of dehydration may be present. The physical examination may show a distended, gas-filled abdomen, which is often tympanitic and diffusely tender. Auscultation reveals bowel sounds, borborygmi, and rushes, which may be loud enough to hear without the stethoscope. The examiner may sometimes find a palpable mass or an incarcerated hernia.


The patient is given nothing orally, and when nausea and vomiting are present, a nasogastric (Levin, Salem Sump) or intestinal (Cantor, Miller-Abbott) tube is placed to remove upper intestinal contents anddecompress the bowel. Fluids and electrolytes are given intravenously. A large intestinal obstruction due to fecal impaction may be relieved by disimpaction or enemas. When obstructions do not resolve with conservative measures and supportive care, surgery may be needed.

Patient care

In partial obstruction, the patient's condition is monitored closely, including assessment of bowel sounds, vital signs, abdominal girth, fluid and electrolyte balance, and acid-base balance. The patient is assessed for signs of dehydration. Frequent oral hygiene is provided. Prescribed pain medications, antiemetics, and antibiotics are administered. Opioids are sometimes withheld or used sparingly because they may slow peristalsis. Noninvasive pain relief strategies (e.g., relaxation techniques, imagery, repositioning, massage, and music therapy) may be effective for individual patients. The patient is asked to alert health care providers if pain changes from colicky to constant, because this may signal perforation. Throughout, the patient receives support and encouragement. Ischemia is the most serious consequence of intestinal obstruction, because it leads to peritonitis, perforation, hemorrhage, and gangrene. Ischemia makes the bowel more permeable, allowing normal intestinal flora such as Escherichia coli and Klebsiella to penetrate the bowel wall and enter the peritoneal cavity, potentially leading to peritonitis and/or septic shock. Intravenous fluids are required; blood products and antibiotics may be needed, depending on complications experienced by the patient.

If conservative treatment fails for partial or incomplete mechanical obstruction, or if the obstruction is initially diagnosed as vascular or mechanical and complete, the patient is prepared for nasogastric suctioning, endoscopy, or surgery. If the patient requires a colostomy or ileostomy (which may be a temporary measure or may be permanent, depending on the cause of the obstruction), an enterostomal therapist makes recommendations regarding stoma location and provides further positive reinforcement and emotional support. Postoperative care is explained; if the patient is well enough to understand, he is taught exercises to aid ventilation and prevent complications due to immobility. Following surgery, all necessary postoperative care is given, including care of the surgical wound, maintenance of ventilatory status and fluid and electrolyte balance, and relief of pain and discomfort. Vital signs are closely monitored. Oral care is provided, along with misting of mucous membranes while the decompression tube remains in place, and the amount and color of drainage are recorded. Clear fluids may be initiated with the tube clamped to determine toleration. The tube is removed and diet advanced as bowel sounds return. Incentive spirometry, antiembolic or pneumatic hose, and early ambulation help to prevent complications related to immobility. Any necessary postoperative activity limitations are discussed with the patient. Before discharge, any prescribed medications, their proper use, desired responses, and adverse effects are reviewed. Incision and/or colostomy care is taught and signs of infection, activity restrictions, and signs or symptoms for which the surgeon should be called are reviewed with the patient before discharge. The importance of following a structured bowel regimen is emphasized (particularly if the cause of obstruction was a fecal impaction). The patient is encouraged to eat a high-fiber diet, drink plenty of fluids, and exercise daily.

nasal obstruction

Blockage of the nasal passages. Common causes of nasal obstruction in adults are irregular septum, enlarged turbinates, and nasal polyps. In children, a common cause is a foreign body, such as food, buttons, or pins. Complications such as infections, sinusitis, and otitis may develop.


Depending upon the cause of the obstruction, nasal douches, inhalations, or operative care, including resection of septum, turbinectomy, removal of polyp, opening and draining sinuses, or removal of foreign body.

upper airway obstruction

Abbreviation: UAO
Any potentially life-threatening abnormality in which the flow of air into and out of the lungs is partially or completely blocked by such conditions as laryngeal swelling, foreign bodies, or angioedema.
See: cardiopulmonary resuscitation; tracheostomy
References in periodicals archive ?
Like many public companies, 3M created the CAO position early in 2005 to reflect the growing importance of finance and accounting and as part of an effort to focus the entire organization on the importance of global financial reporting, says Smyth, who also is a vice-president.
In this case, it may be helpful for the board of directors to designate an outside director as the principal contact with the CAO and auditors.
Most CAO belts feature a polyester or cotton backing; ounce for ounce, a polyester backing is stronger than a cotton backing, and polyester offers better tear and puncture resistance than cotton.
CAO is the sole supplier of imported jet fuel to the civil aviation industry of China.
Yaroslavsky said he believes the new powers the board may grant the CAO will help in recruitment and improve county government services.
In OKYC, CAO has a 26% stake, and 29% stake is owned by Korea National Oil Corp.
Give the candidates who have turned down the CAO position some credit.
CAO is majority owned by China Aviation Oil Holding Company (CAOHC), which is directly supervised by the central government of China and supplies oil at more than 100 airports in the world's most populous nation.
PHOENIX -- LED innovator and design/integration firm CAO Group has selected Avnet Electronics Marketing to distribute its Dynasty family of high-brightness LED devices, as well as its entire line of solid state illumination products and system-level solutions.
5, 2013 /PRNewswire/ -- The CAO Group (CAO), a world-leading high-technology company, continues to lead innovation in the forensic light industry with the launch of the new UltraLite (TM) ALS Turbo heads, which results in twice the amount of evidence revealed.
Before the first visit, the CAO is debriefed by the chaplain and CNO who conducted the notification, Hughey said.
This change to make the job more like its counterparts in other California counties will no doubt help supervisors in their future search for a successor to CAO David Janssen, who came out of retirement when they couldn't persuade any qualified candidates to take the job.