| Contents | Previous | Next |
The sensory health system relates to the integrity of the senses including proprioception, taste, smell, hearing, vision, and perception of pain. Alterations in these senses could be mechanical or physiological.
Two cases have been selected to demonstrate an alteration in sensor. perception (alteration in vision) with different etiologies but similar patient effect and concern. For most patients presenting to the ED. pain is the impetus for seeking help. Many of the case studies throughout this series have had pain and pain management integrated into the overall care plan for the patient. The severity of pain rating by the patient is a defining characteristic for identifying the patient acuity level in the triage system presented.
| SENSORY PERCEPTION VF | PAIN |
| hearing | acute |
| proprioception | chronic |
| smell | ache |
| taste | pressure |
| touch | soreness |
| vision | throbbing |
pain
chronic pain
altered sensory perception (specify)
unilateral neglect
| Sensory Health System | |||
| Level 1 | Level 2 | Level 3 | Level 4 |
| Reddened, itching eyes for several days; no sight loss | Reddened, itchy eyes wit periorbital edema | Sudden decrease or loss of vision, severe eye pain | |
| Periorbital edema without trauma or associated symptoms | Foreign body sensation present; no hx of foreign body entry; no foreign body present | Chemical splash in eye(s); foreign body; eye irrigated at5 scene | |
| Chronic eye pain; gradual vision change | Periorbital swelling; bruising with direct trauma; sudden severe eye pain | ||
| Corneal abrasion more than 24 hr ago | Corneal abrasion within 24 hr | Corneal ulcer | Penetrating trauma to eye |
| Cold injury to external ear | Amputation of external ear | ||
| Nonbloody ear drainage; temperature<102° F | Nonbloody ear drainage; temperature<102° F | Bloody drainage from ear; no hx of trauma | Bloody drainage from ear after trauma |
| Gradual hearing loss; no history of trauma | Gradual hearing loss with history of trauma | Acute onset of hearing loss | |
| Foreign body in ear; no discomfort | Foreign body in ear; complains of mild pain | Foreign body in ear with severe pain; bug in ear | |
| Tinnitus with temperature >102° F | Tinnitus; hx of aspirin ingestion or vertigo | ||
| Mild to moderate pain; periodic or intermittent | Moderate to severe pain; persistent | Incapacitating pain | |
Leticia V. M. Nanda, RN, MS
Anne is a 60-year-old, slightly obese, white female who is brought to the ED by her husband at 2 o'clock in the morning. She has been experiencing severe, deep, boring pain; decreased vision acuity: and redness and photophobia of her left eye (OS) for the last 7 to 8 hr. A private physician had seen her earlier when she was having mild to moderate ocular complaints, and she was diagnosed with having viral conjunctivitis. She was advised to apply cool compresses to OS and take Tylenol two tablets every 4 hr for eye pain. Over the next few hours her OS pain has rapidly increased in intensity and her vision has become worse.
Triage Assessment. Acuity Level IV: sudden decrease in vision, severe eye pain
In the treatment area. Anne reports that she has had four similar episodes of ocular problems in the last 5 weeks but that her vision had improved and the pain had disappeared spontaneously after 1 to 2 hr.
Anne is alert and oriented x3. and her skin is warm and dry. Her respirations are deep and regular. Peripheral pulses are strong and regular.
Anne reports having a fairly active life-style and denies any medical problems except a history of upper respiratory tract infection 2 to 3 weeks ago, which has completely resolved. She states she has been very upset over the death of her only daughter from an automobile accident 2 weeks ago.
The physician's ocular findings are reported as follows: Right eye (OD) vision 20/20, OS vision 20/100 PHNI (no improvement over pinhole). OD shows a shallow anterior chamber (AC) and narrow angle, otherwise within normal limits. OS shows a 5- to 6-mm dilated and non reactive pupil. Extra ocular movements (EOMs. are full, and external exam is normal. The left eye slitlamp exam (SLE) shows the conjunctiva 2+ injected: the cornea has moderate stromal edema; the A C is shallow, with trace cells or flare; the iris is very convex; lens is clear. Funduscopic exam of the left eye reveals poor view of the fundus. Tension by applanation tonometer shows the right eye at 12 mm Hg and the left eye at 60 mm Hg. Gonioscopy of the right eye shows a narrow angle: the left eye angle is closed x360°.
The medical diagnosis is acute angle-closure glaucoma of the left eye.
1. What is the pathophysiological basis for Anne's ocular problem?
The aqueous humor of the eye is a relatively cell-free, protein-free, transparent fluid produced by epithelial cells of the ciliary body and secreted into the posterior chamber. The aqueous humor flows through the pupil and enters the vascular system of the eye through the corneoscleral trabecular meshwork and canal of Schlemm (1). The intraocular pressure (IOP) reflects the balance between the rate of aqueous fluid formation and the amount of resistance to its outflow from the AC into the venous system. In the normal eye, the IOP is relatively constant with a normal range of 10 to 21 mm Hg. The IOP is increased when there is marked obstruction in aqueous outflow from the AC as seen in most kinds of glaucoma. In very few cases. IOP may be raised by hyper secretion of aqueous fluid or high central venous pressure (2). Elevated IOP will eventually cause damage to the optic nerve if not recognized early and controlled. Patients with IOP greater than 21 mm Hg need further evaluation, because they are at higher risk of developing glaucoma (1,3). The glaucoma as may be subdivided according to their mechanism of development into primary (chronic) open-angle glaucoma, primary angle-closure glaucoma, and the secondary glaucoma. Primary open-angle glaucoma accounts for the majority of all cases of glaucoma. The primary angle-closure glaucoma are diagnosed in a smaller population of glaucoma patients. In acute angle-closure glaucoma, the primary cause of elevated pressure is closure of the AC angle. There is an apposition of the peripheral iris to the trabecular meshwork blocking the aqueous humor from the outflow facilities. The sudden increase in the IOP as the angle closes rapidly causes dramatic symptoms. The patient has severe eye pain, the pupil becomes non reactive or slightly reactive to light, vision is blurred or foggy, and the patient sometimes sees colored halos around lights. The patient frequently experiences severe headache and sometimes nausea and vomiting (1,4). The pain that Anne is experiencing is due to the rapid and persistent rise in the eye pressure. Blurred or lost vision and colored halos around lights are attributed to corneal edema from the rapid rise in pressure (1,2). Paralysis of the pupillary sphincter from pressure elevation causes mydriasis (1). Venous congestion is manifested by conjunctival injection, engorgement of iris blood vessels, and, sometimes, central retinal vein occlusion. These occur when the IOP is greater than that of the intraocular veins (1). Autonomic stimulation causes nausea and vomiting. Bradycardia and sweating are also noted as effects of oculocardiac reflex activation during the acute attack of angle-closure glaucoma (1).
Acute angle-closure glaucoma is a relatively rare disease which accounts for a small percentage of all causes of glaucoma. The occurrence of acute angle-closure glaucoma is an emergency which demands prompt diagnosis and intervention. An IOP of 50 mm Hg or above may produce irreversible ocular damage within a few hours resulting in significant permanent loss of vision if management is delayed (5).
A patient with a very shallow AC or a very narrow chamber angle. who is hypermetropic, is predisposed to having acute glaucoma (2). The anatomical narrowness of the AC angle is positively correlated with the development of acute glaucoma. Acute glaucoma very rarely occurs before the age of 50 (6). Acute angle-closure glaucoma is more common in women than men (5,7). An interesting finding is that acute glaucoma is not common in the black population even when there is an anatomical narrow chamber angle or a convex iris (2).
In anatomically predisposed eyes, acute glaucoma can be precipitated with the use of mydriatic agents (7). Drugs or any circumstances that cause pupillary dilation such as dim light, sympathetic nervous system stimulation (e.g., strong emotion), and others can precipitate an acute attack. Stronger miotics, particularly cholinesterase inhibitors, are known to precipitate angle-closure glaucoma (1,2).
An accurate history of the patient's acute onset of attack usually points to the diagnosis of acute angle-closure glaucoma, even before the patient is examined. However, there are special tools that can confirm the diagnosis.
Slitlamp bio-microscopy is an ophthalmic tool utilized to examine the frontal view of the outer part as well as the AC of the eye. The patient and the examiner sit on opposite sides of the slitlamp during the exam.
TIP: The patient must keep his or her forehead firmly against the forehead rest for better examination of the eye and, thereby, a more accurate diagnosis.
A tonometer is used to measure the IOP. There are two types commonly used: the Schiotz and applanation tonometers. The Schiotz tonometer is the more traditional instrument. It is relatively inexpensive and more widely used. However, it can be unreliable, especially in severe myopia, and frequently can cause corneal abrasions. The applanation tonometer is safer and more accurate than the Schiotz but is more expensive. The Schiotz tonometer is held on the patient's cornea while the patient is in a lying position. Topical anesthesia is applied on the cornea before the procedure. The extent to which the plunger of the tonometer indents the cornea is shown on a scale. A conversion table is used to convert the scale reading to the corresponding intraocular pressure. During acute glaucoma. IOP may be 40 to 100mm Hg.
The gonioscope is a tool used to look at the AC angle and search for the cause of aqueous obstruction in glaucoma. Gonioscopic lenses may be indirect wherein the angle being examined is reflected through a mirror, or the angle can be examined directly. During acute glaucoma, extensive closure of the angle will be found. The presence of peripheral anterior synechiae may be detected through the use of a Zeiss four-mirror lens with the Slitlamp microscope.
Once the diagnosis of acute angle-closure glaucoma is established. medical treatment is initiated as soon as possible. The nurse should anticipate the physician to order pressure lowering agents for the eye. such as pilocarpine 2 to 4%, 1 or 2 drops instilled on the affected eye at frequent intervals: Timoptic 0.25 to 0.5% or equivalent; oral glycerol 50% 0.7 to 1.5 ml/kg body weight; and 250 to 500 mg oral or intravenous Diamox. Intravenous mannitol 20% 1 to 2 gm/kg body weight may be ordered if the above eye medications fail to lower the IOP. Analgesics such as Tylenol, Demerol, or morphine are also needed to relieve the pain. Demerol injection is usually preferred because it is not likely to produce nausea and subsequently vomiting. The IOP is expected to decrease within a few minutes after administration of medications. If the IOP is refractory to intensive medical treatment, the patient should undergo surgical intervention without further delay (2). Otherwise, extensive damage to the optic nerve with permanent loss of vision will occur. Peripheral iridectomy is usually the procedure of choice. With technological advancements, laser iridectomy has replaced surgical iridectomy.
The nurse should monitor the patient for ocular as well as systemic side effects of medications. Pilocarpine, a miotic drug, is a parasympathetic agent. The most common side effects are headache, ocular pain, blurred vision, nausea, vomiting, and abdominal pain. Systemic effects are rare and usually occur with very frequent instillations of the drug (8). Timoptic is a p-adrenergic blocking agent. It is contraindicated in patients with asthma, COPD. and heart failure. Orthostatic hypotension can occur. The patient's heart rate should be monitored and Timoptic should be held for bradycardia with physician notification.
TIP: Finger pressure should be applied over the puncta for about 15 to 30 seconds after the eye drops are administered to minimize the risk of system absorption and reaction.
TIP: Strict intake and output measurement is the best way to monitor fluid balance. To minimize nausea and vomiting with glycerol administration, the drug should be mixed with fruit juice over cracked ice and sipped through a straw.
A patient who is suffering from an attack of acute angle-closure glaucoma has similar nursing problems as many patients who have other kinds of ocular emergencies such as alkaline or chemical injuries to the eye, and penetrating injuries (e.g., from a fish hook).
Diagnosis: Pain related to increased intraocular pressure
Desired patient outcome: The patient will state that the pain is relieved or diminished: the patient will not demonstrate nonverbal cues of pain.
Diagnosis: Visual sensory-perceptual alteration related to decreased sight and proprioception with visual changes in left eye
Desired patient outcome: The patient will describe increased visual acuity and ability to place objects in relationship to each other.
Diagnosis: Potential for injury related to impaired vision
Desired patient outcome: The patient will remain free from injury: the patient will demonstrate ways to move and interact with the environment that minimize risk.
Diagnosis: Impaired mobility related to impaired vision
Desired patient outcome: The patient will demonstrate modified behaviors and actions that will allow her to participate in her care.
Diagnosis: Anxiety related to pain, sudden diminished vision, unfamiliar environment and procedures
Desired patient outcome: The patient will describe her feelings of anxiety and use effective coping mechanisms to manage self. The patient will describe an increase in psychological and physiological comfort.
Diagnosis: Knowledge deficit related to acute angle-closure glaucoma, diagnostic procedures, and treatment
Desired patient outcome: The patient will verbalize basic understanding of the disease process. The patient will follow instructions during diagnostic procedures. The patient will participate in the administration of medications and will state the potential side effects that should be reported to the nurse immediately. At discharge, the patient will be able to demonstrate the procedure for administering her own eye drops.
Diagnosis: Potential/or ineffective coping related to potential loss of vision
Desired patient outcome: The patient will demonstrate internal coping strategies by asking appropriate questions, seeking assistance from her husband and the nursing staff as required, and participating actively in her care as needed.
Diagnosis: Potential/or dysfunctional grieving related to recent death of only child in a traumatic accident
Desired patient outcome: The patient will be able to discuss the recent traumatic event. The patient will state that feelings of loss. alterations in sleep-wake patterns, alterations in desire for food and fluids, lack of interest in outside activities, and so on, are normal responses to the death of a loved one. The patient will be able to identify internal and external supports that can assist her during the grief period.
Having an acute onset of pain and loss of vision can be a very difficult experience for Anne. Anxiety is a prominent feature in any person who comes to the ED with vision changes. A care plan that emphasizes education and the patient's understanding of the disease process, diagnostic tests, and treatments will definitely benefit her.
Besides assessing for the intensity and character of ocular pain. giving ordered analgesics, and evaluating the patient's response, an attentive and caring attitude from the nurse is imperative. Assure the patient that appropriate measures are being implemented. Interdependent nursing actions of prompt administration of medications to lower IOP and monitoring of the patient for complications are indicated. The patient's environment should be controlled to minimize risk of injury. The patient should be placed on a stretcher with side rails up, in a well-lighted room. The call bell should be within the patient's reach. Hazards on the floor between the bed, bathroom, and door should be removed. Anne should be encouraged to ask for assistance with getting out of bed until she is able to demonstrate that she is able to negotiate in her environment.
Teaching should be ongoing, particularly in the use of her medications and their complications. Anne should be asked to participate as she is able in her care.
Anne should be encouraged to grieve for her daughter's death. A social worker may be helpful to Anne and her family in this process. Anne's acute glaucoma may have been precipitated by her emotional response to her daughter's death.
If the patient is admitted to the hospital for further treatment, the nursing report should include Anne's current response to interventions, coping strategies, and understanding other condition.
Patricia C. Epifanio, RN, MS, CEN
Mr. J. Jones presents to the triage desk of the ED complaining of a “teardrop”on his right eye. Mr. Jones reports that he had been hammering on a screwdriver in his home workshop yesterday. He was attempting to straighten the screwdriver with a hammer when he felt something fly into his right eye. He suspects it was a metal sliver from the screwdriver. Initially he had a small amount of pain and tearing of his right eye. both of which subsided quickly. It was not until the next day that fie' realized that he had a teardrop-like protrusion which he describes as being located at the lower margin of the iris and the sclera of his right eye. Mr. Jones does not wear corrective lenses. He was not wearing protective glasses at the time of the injury.
Mr. Jones' primary and secondary assessments are within normal limits. He denies any significant medical problems. He denies smoking and does not use alcohol or recreational drugs. He is on no medications and denies any known drug allergies.
His last tetanus immunization was 2 years ago when he accidently punctured his foot with a nail.
Triage Assessment, Acuity Level IV: penetrating trauma to eye. foreign-body sensation present.
Mr. Jones had bilateral eye patches placed and was taken immediately to the treatment area.
Even though Mr. Jones is not experiencing pain, foreign bodies in and around the eye are usually quite painful and can cause significant visual loss if not treated properly. Potential areas for injury are the skin of the eyelid; penetration into the conjunctiva; penetration into the cornea, either superficially or deeply; or deep penetration into the anterior or posterior chambers. Foreign-body injuries to the eye usually occur from shattered particles in work-related accidents (drilling. sanding) from explosions (gunshot, fireworks), or, in the case of children, from sand or dirt.
Common complaints expressed by patients with foreign-body sensations include pain, itchiness, and a sensation that the object is "moving around in the eye." Actually, the foreign body is usually lodged within the conjunctiva under the upper lid and is not moving: but with each blink of the eyelid a different area of the cornea may be irritated giving the impression of foreign-body movement.
Foreign bodies that are lodged in the cul-de-sacs under the upper and lower lids can usually be removed by careful swabbing of the area with a cotton-tip swab and gentle irrigation with normal saline. Conjunctival foreign bodies that are on the surface of the conjunctiva or have only superficially penetrated the conjunctiva of the eyeball (bulbar conjunctiva) can usually be wiped off with a cotton swab or toothless forcep after anesthetizing the eye. Sometimes conjunctiva! foreign bodies leave an underlying laceration that could lead to infection. Patients, and especially children, with an underlying laceration should be admitted to the hospital for exploration of the wound under anesthesia.
Corneal foreign bodies are very common and are usually embedded. These are not easily removed, and removal is not possible without anesthetizing the cornea with a topical agent. Sometimes irrigating the cornea with sterile saline, directing the flow toward the foreign body, will dislodge the object. If irrigation is unsuccessful, then the use of a cotton swab or removal by needle may be indicated. This procedure is usually performed by an ophthalmologist. If the removal of a foreign body is followed by obvious leakage of fluid or there is shallowing of the anterior chamber of the eye on exam. corneal perforation should be suspected and treated immediately by an ophthalmologist.
Foreign bodies that are made of vegetative substances such as wood frequently cause infection. Metallic foreign bodies, especially those made of iron. cause rust to form in the underlying tissue within only 2 to 4 hr. A metallic foreign body that has been lodged for 6 to 8 hr may have a complete rust ring around it. When this occurs, the foreign body may be easily removed but the rust ring remains. Patients who have rust rings may need these removed surgically by an ophthalmologist.
If a metallic foreign body remains embedded for several days before medical assistance is sought, necrosis of underlying tissue may occur. Although this necrosis may ease the removal of the foreign body and the rust ring, there is greater risk for infection and corneal ulceration.
Mr. Jones' situation involves a metal object. The object is deeply embedded in the posterior chamber of the eye and a teardrop-like protrusion has formed. This is considered an intraocular foreign body and constitutes a surgical emergency.
Visual acuity testing is usually performed using the Snellen chart at 20 ft. A Rosenbaum chart, a hand-held version of the Snellen chart. can be used for non ambulatory patients and is held 14 inches from the eyes. Visual acuity should be checked in both eyes, even when an injury or problem is reported in only one eye. The patient should also be checked with corrective lenses in place for comparison. If the patient's glasses are unavailable, then a pinhole test can be performed. A pinhole is put into a 3 X 5 card or any other piece of cardboard, and the cardboard is held up to the patient's eye. This simulates the effect gained from corrective lenses. The visual acuity test helps to determine the degree of visual loss that may be present.
The physician should gently palpate the eye and eye socket of a patient with a penetrating injury to the eye. If the globe has ruptured and there has been extravasation of the vitreous humor, the patient may have "soft eye," a palpated sensation of lost density of the eyeball. Examination of the tissue around the eye will help determine if infection has occurred or if there are other penetrated objects undetected by the patient. The physician frequently will examine the eye with the aid of the Slitlamp.
The physician will also usually order soft-tissue x-rays and CAT scan of the eye in order to prepare for surgical removal of a deeply embedded foreign object such as that of Mr. Jones.
At CAT scan evaluation, it was determined that Mr. Jones will require surgery on the posterior chamber of the eye to remove the metal sliver and some of the surrounding necrotic vitreous humor. This type of surgery requires the use of fiber optics. If it is determined during surgery that the patient has experienced significant globe disruption, then enucleation of the eye may need to be performed. This is a potentially catastrophic outcome for a patient who is otherwise healthy and is feeling "fine."
Superficial wounds or abrasions caused by foreign-body irritations of the conjunctiva or sclera are usually managed conservatively. Foreign-body penetration into the cornea should be managed with similar considerations as a corneal abrasion. Topical anesthetics for pain should not be used because the cornea will heal too slowly with these applied. If pain relief is needed, then a long-acting cycloplegic such as 1/4% Isopto Hyoscine (scopolamine) is usually ordered and can be instilled. Pain usually occurs from spasm of the cilia, which is a reflex reaction to stimulation of corneal nerve endings. Cycloplegics paralyze the ciliary body muscle, relieving the spasm. If cycloplegics are not indicated, then a systemic nonsteroidal antiinflammatory agent such as acetaminophen can be used.
Infection is a serious consideration when foreign bodies penetrate the cornea. Antibiotic coverage is frequently indicated. If no haze is present on exam around the site of the foreign body. a pressure bandage over the eye after instillation of the antibiotic is indicated for 24 hr.
After 24 hr, the bandage is removed and antibiotics instilled every 3 to 4 waking hours until the epithelium is healed. The pressure patch should not be applied if there is indication of an infection, such as haze in the surrounding tissue. Topical steroids are also avoided as they inhibit wound healing, encourage fungal infections, and in some patients can increase intraocular pressure.
Nursing diagnoses for the patient with a penetrating eye injury include the following:
Diagnosis: Pain related to irritation of tissue by foreign object
Desired patient outcome: The patient will state that there is relief of pain or reduction in the sensation of pain to a tolerable level; the patient will not exhibit nonverbal cues of pain.
Diagnosis: Visual sensory-perceptual alteration related to foreign body lodged in visual field and irritation a/surrounding tissue; temporary blindness with both eyes patched
Desired patient outcome: The patient demonstrates the ability to adapt and compensate for visual field deficit by maximizing use of his other unimpaired senses.
Diagnosis: Anxiety related to sudden loss of vision and implications of need for hospitalization and surgery
Desired patient outcome: The patient will describe his feelings of anxiety and use effective coping mechanisms to manage self: the patient will describe an increase in psychological and physiological comfort.
Diagnosis: Knowledge deficit related to the medical treatment of intraocular foreign body and home care requirements following surgery
Desired patient outcome: The patient will describe in basic terms the surgical procedure to be performed and implications for recovery; the patient will describe the role he will play in his postoperative care including use of eye drops and dressing changes.
Diagnosis: Potential for injury related to diminished (obstruction) visual field
Desired patient outcome: The patient will remain free from injury; the patient will demonstrate ways to move and interact within the environment that minimize risk.
Diagnosis: Impaired mobility related to impaired vision
Desired patient outcome: The patient will actively participate in his care; the patient will demonstrate modified behaviors and actions that will allow him to participate in his care.
Mr. Jones had both eyes patched at triage to reduce ocular movement to prevent further damage or irritation by the metal sliver.
TIP: Because eyes move together, both eyes should be patched even in the presence of single-eye injuries. In cases of a ruptured globe, pressure can be avoided when patching the eyes by using a metal shield or simple paper cup lightly taped over the eye. The areas of pressure should be on the bony orbit. When taping a patch in place, use five 5-inch strips of 1 -inch tape. The strips should be placed on the diagonal from the medial orbital rim to the lateral cheek bone so as not to pull on the face To avoid skin irritation use paper or plastic tape.
The nurse should be aware of the patient's pain and anxiety and administer medications as indicated. Frequent verbal interactions with offers of reassurance or providing education are helpful. The patient should be informed of normal prep-and postoperative events that will occur and how he will be expected to participate. Questions regarding temporary or permanent loss of sight should be answered honestly, with reassurances that the care being provided will hopefully minimize any permanent problems. The patient should be prepared for surgery in the usual manner. Tetanus diphtheria toxoid or plain tetanus toxoid should be given, if the patient's immunization is not up to date.
At the time of discharge the nursing plan of care should include patient education on strategies to prevent future injury. Mr. Jones should be instructed to wear shatterproof eyeglasses with side shields or protective goggles whether he is at work or at home.
Lubeck, D: Penetrating ocular injuries. Emerg Med Clin North Am 1988;6(1): 127-140.
Melamed M: The injured eye at first sight. Emerg Med October 15,1988:86-98.
Nurse’s Reference Library: Emergencies Springhouse, PA: Springhouse, 1985.
Rea R, Bourg P, Parker JG, Rushing D, eds.: Emergency nursing core curriculum.3rd ed. Philadelphia: Saunders, 1987:485-487,493-494.
Rosen P, Baker II F, Braen R, Dailey R, Levy R, eds.: Emergency medicine: concepts and clinical practice. 2nd ed. St. louis : Mosby, 1988:648-649.
Sheehy SB, Barber J: Emergency nursing principles and practice. 2nd ed. St. Louis: Mosby, 1987.
Stoke Hr: Ocular foreign bodies. In: Donabred L, Hoole AJ, Fletcher RH, Pichard Jr CG, eds Manual of clinical problems in adult ambulatory care. Boston: Little, Brown, 1985:19-21.