 |
||
| Departments | |
||
Tips from Other Journals
- Community and Family Medicine
- Outcomes in Patients with Episodes of Low Back Pain
- Diagnostic Evaluation of Patients with Palpitations
Diagnosis and Treatment of Acute Diverticulitis
Acquired diverticular disease affects approximately 5 to 10 percent of the Western population older than 45 years and approximately 80 percent of persons older than 85 years. Ferzoco and colleagues review the diagnosis and treatment of this gastrointestinal condition.
It is estimated that 20 percent of patients with diverticula will develop symptomatic diverticulitis requiring medical or surgical intervention. Up to 20 percent of these patients will be younger than 50 years. Diverticulitis is thought to be more severe in younger patients, but this may be a result of delayed diagnosis. Recent data have also shown that diverticulitis has a similar incidence in men and women and that up to two thirds of patients younger than 50 years of age will remain disease-free for up to nine years after the initial attack.
Colonic diverticula are related primarily to two factors: increased intraluminal pressure and a weakening of the bowel wall. Patients with known diverticula have been found to have elevated resting colonic pressures. The Western diet, which tends to be low in dietary fiber and high in refined carbohydrates, is also believed to be a contributing factor. Once the pockets of diverticula form between the mesenteric and lateral taeniae coli, particles of undigested food may become inspissated within them. This results in obstruction at the neck of the diverticulum, allowing for increased mucus secretion and overgrowth of normal colonic bacteria, which produces overdistention of the diverticular sacs and microperforations. What follows is clinical disease, which may range from small pericolonic abscesses to fecal peritonitis. Colovesical fistulae formation is the most common complication; colovaginal and colocutaneous fistulae are less common.
The clinical diagnosis of diverticulitis is suggested by abdominal pain that is initially hypogastric but then localizes to the left lower quadrant. Urinary symptoms may occur if the affected colonic segment is close to the bladder. A lower quadrant abdominal or rectal mass may be palpated, but associated rectal bleeding is uncommon and suggests an alternative diagnosis. About 85 percent of cases of acute diverticulitis involve the descending or sigmoid colon; however, right-sided disease may also occur and is reported more frequently in persons of Asian descent. Sigmoid diverticulitis may mimic acute appendicitis if a redundant colon is in the suprapubic region or lower right quadrant.
Previously, diverticular disease was diagnosed using a contrast barium enema. However, because of the possibility of an obstructing fecalith being dislodged by insufflation and causing bowel perforation, computed tomographic (CT) scanning is now the diagnostic procedure of choice. Besides being safe and cost-effective, CT can also be used to assist percutaneous drainage of an abscess. False-negative rates using CT are reported to range from 2 to 21 percent. Ultrasonography has been advocated for the diagnosis and treatment of acute diverticulitis but is more operator-dependent than CT. Abdominal tenderness may prevent adequate use of pressure and produce suboptimal images. Neither ultrasound nor CT can distinguish between an inflammatory and a neoplastic mass.
Treatment of diverticulitis can proceed on an outpatient basis for a patient with a mild first attack who is able to tolerate oral hydration and an antibiotic. Treatment consists of a liquid diet and seven to 10 days of therapy with broad-spectrum antimicrobials such as metronidazole and ciprofloxacin. Patients with more severe illness, or those who cannot tolerate oral hydration or who have pain severe enough to require narcotic analgesia, should be hospitalized. Because feeding increases intracolonic pressure, patients should receive nothing by mouth and should be treated with intravenous triple therapy consisting of ampicillin, gentamicin and metronidazole. Alternative monotherapy includes piperacillin or tazobactam. If narcotics are required for pain control, meperidine is recommended because morphine sulfate causes colonic spasm. If pain, fever and leukocytosis do not resolve within three days, further imaging studies are indicated. If an abscess is uncovered and is more than 5 cm in size, CT-guided drainage and adequate antibiotic coverage should be considered.
Approximately 20 percent of patients with diverticulitis will require surgical intervention. Bowel resection is usually recommended for recurrent episodes of diverticulitis or if fistulae are present. Resection with primary anastomosis is now the procedure of choice unless generalized peritonitis has occurred, in which case a two-stage procedure is usually necessary. Rarely is the older three-stage Hartmann's procedure required. Twenty-seven percent of patients will still have some recurrence of symptoms even after surgery.
The authors believe it is prudent for all patients with diverticulitis, even those who have undergone surgical resection, to be encouraged to maintain a diet high in fiber. In addition, the authors recommend that all patients who recover without surgical intervention undergo colonoscopy to rule out the presence of a neoplasm.
JEFFREY T. KIRCHNER, D.O.
Ferzoco LB, et al. Acute diverticulitis. N Engl J Med May 21, 1998;338:1521-6.
Amiodarone or Sotalol for Recurrent Atrial Fibrillation
Class III antiarrhythmic agents have been reported to be useful in maintaining sinus rhythm in patients with recurrent symptomatic atrial fibrillation or with chronic atrial fibrillation recently cardioverted to sinus rhythm. Kochiadakis and associates conducted a randomized, double-blind study to compare the safety and efficacy of amiodarone and sotalol, two class III antiarrhythmic drugs, in the treatment of patients with recurrent symptomatic atrial fibrillation.
Seventy patients who were admitted to the emergency department with symptomatic chronic or paroxysmal atrial fibrillation were included in the study. Exclusion criteria were acute myocardial infarction occurring less than one week before entry into the trial, significant comorbidities such as decreased ejection fraction, unstable hepatic or renal function or hyperthyroidism. Patients who had a life expectancy of less than one year due to to a major medical problem were also excluded from the study.
After restoration of sinus rhythm, eligible patients were randomly assigned to receive either amiodarone or sotalol. Amiodarone was initiated with a loading dose of 800 to 1,600 mg per day for seven to 14 days orally and then tapered to a maintenance dosage of 200 mg per day. Patients randomized to sotalol began therapy with 80 mg twice daily; this dosage was titrated up to a maximum dosage of 360 mg twice daily. If adverse effects were noted by the patient or if the rate-corrected QT interval was more than 0.5 seconds, the maintenance dosage of sotalol was lowered accordingly.
The success rate was high for both drugs. Other studies have shown that just 25 percent of patients who converted to sinus rhythm remain so after one year without antiarrhythmic therapy. At one year follow-up in this study, 71 percent of the patients who received amiodarone were still in sinus rhythm, compared with 40 percent of those who received sotalol. Results were not affected by age, sex, left atrial size, fibrillation pattern or underlying cardiac disease.
The authors conclude that amiodarone and sotalol are equally safe when administered over a one-year period. Amiodarone appears to be more effective than sotalol in preventing the recurrence of symptomatic atrial fibrillation. Few patients discontinued therapy with either drug because of adverse effects, although further studies using greater numbers of patients and longer follow-up periods are recommended.
RICHARD SADOVSKY, M.D.
Kochiadakis GE, et al. Low-dose amiodarone versus sotalol for suppression of recurrent symptomatic atrial fibrillation. Am J Cardiol April 15, 1998;81:995-8.
Anthrax Vaccine: A Clinical Review of the Data
Consultants for The Medical Letter on Drugs and Therapeutics reviewed data on the anthrax vaccine following the government's decision to vaccinate more than 2 million members of the armed forces.
Anthrax is caused by the gram-positive, spore-forming bacterium Bacillus anthracis. The spores can persist in nature for many years and may infect grazing animals. Although cutaneous anthrax is the most common form of the disease, inhaled anthrax is the most significant concern for U.S. military forces. Inhaled anthrax can cause fever, cough and weakness within one to six days of infection and may progress in two to three days to respiratory failure, septic shock and multiorgan failure. The mortality rate in persons with untreated inhalation anthrax is about 95 percent.
The anthrax vaccine is produced as a sterile filtrate of cultures of an avirulent strain that elaborates protective antigen. Although no results from controlled trials are available, the vaccine has been licensed by the U.S. Food and Drug Administration since 1970. Experience with the current vaccine in high-risk industries with exposure to imported animal products has shown that anthrax infection has not occurred in workers who received two or more doses of vaccine but has occurred in some unvaccinated workers. A protective antibody response does not usually develop until seven days after the second dose of the vaccine. The vaccine is well tolerated, and erythema and tenderness at the injection site are usually mild. Fever and chills are rare.
Anthrax vaccine is given in a volume of 0.5 mL subcutaneously at zero, two and four weeks, and at six, 12 and 18 months. An annual booster shot is recommended. In emergency exposure, the vaccine should be given immediately and repeated two weeks later with appropriate antibiotic coverage.
The anthrax bacillus is highly susceptible in vitro to penicillin, amoxicillin, chloramphenicol, doxycycline, erythromycin, streptomycin and ciprofloxacin. It is resistant to third-generation cephalosporins.
In animal studies, 30 days of treatment with an antibiotic was generally effective, but vaccination alone was not sufficient. The current recommendation for prophylaxis after exposure is vaccination plus oral doxycycline, in a dosage of 100 mg twice daily, or ciprofloxacin, in a dosage of 500 mg twice daily, for at least 30 days. Symptomatic patients with inhalation anthrax should be treated with ciprofloxacin, in a dosage of 400 mg intravenously every eight to 12 hours, until susceptibility tests are available.
Medical Letter consultants conclude that anthrax vaccine is safe and effective for preexposure prevention of anthrax. Following exposure, an unvaccinated person should receive vaccination and a prolonged course of antimicrobial prophylaxis.
BARBARA APGAR, M.D., M.S.
Medical Letter consultants. Anthrax vaccine. Med Lett Drugs Ther May 8, 1998:40(1026):52-3.
Outcomes in Patients With Episodes of Low Back Pain
In two separate surveys, a little more than one third of adults reported having an episode of significant low back pain over the course of one year. Low back pain is a common presenting complaint in family practice. Croft and colleagues conducted a prospective study to investigate the conventional belief that over 90 percent of such episodes resolve within one month.
All patients with low back pain presenting to two general practices during a one-year period were considered for the study. Patients were excluded if they had visited a physician because of low back pain during the previous three months, if the pain occurred only in the thoracic region of the back or if the symptoms were attributed to gynecologic or urinary conditions. The researchers reviewed the records for subsequent consultations of these patients for six months after the initial consultation and conducted interviews with a subgroup who had previously taken part in a comprehensive survey of patients at the two practices.
In general, women were found to be more likely than men to visit a physician because of low back pain. In both sexes, the highest consultation rates were seen in patients from 45 to 59 years of age. Of the 463 patients participating in the study, 275 (59 percent) did not consult a physician again after the initial visit during the six months monitored. Of the 188 patients who made return visits because of low back pain, 150 patients (32 percent) did so within three months of their initial visit. Men and women were equally likely to seek a repeat consultation, but repeat consultations were less common in patients younger than 30 years.
Approximately one half (218) of the patients who were seen with a new episode of low back pain were interviewed by nursing staff within two weeks of the initial visit and at three and 12 months thereafter. Five patients (2 percent) reported complete recovery by the first interview, 39 patients (21 percent) reported complete resolution of symptoms by three months and 42 patients reported complete response (25 percent) by 12 months.
The authors conclude that only a minority of patients with low back pain recovered within three months of the initial visit. Although most patients did not return to their physicians, only one fourth reported a full recovery one year after the initial visit. The authors attribute the difference in their study findings from those of previous studies to selection bias and equating "recovery" with no further visits to health care professionals. They also advocate that low back pain be considered a long-term chronic problem in most patients, particularly in those more than 30 years of age.
ANNE D. WALLING, M.D.
Croft PR, et al. Outcome of low back pain in general practice: a prospective study. BMJ May 1998;316:1356-9.
Clinical Features and Outcomes in Patients with Endocarditis
Previously published studies have suggested that the clinical presentation of endocarditis tends to be more subtle in elderly patients than in younger patients. Older patients reportedly have fewer symptoms, including fever, and this results in delayed diagnosis. This delay may cause a higher complication rate among the elderly. Gagliardi and colleagues conducted a retrospective study of patients who were hospitalized with endocarditis to compare clinical features and outcomes in elderly and younger patients with native valve endocarditis.
A total of 108 patients who had been hospitalized with infective endocarditis between 1986 and 1997 were selected for the study. The patients were divided into two groups: those older than 65 years and those 30 to 59 years of age. Researchers excluded patients between 60 and 64 years of age in order to capture distinct age-related differences in the two groups. They also excluded intravenous drug users and patients with prosthetic valves, as these patients tend to have unique features that affect their outcome. Sixty-four patients were assigned to the younger group, and 44 were assigned to the elderly group. Data collected included the presence of comorbid illnesses; fever higher than 38šC (104šF) on two or more occasions; the specific organisms isolated from at least two or more blood cultures; the degree of valvular involvement based on echocardiographic findings; new onset of renal failure (creatinine level higher than 2 mg per dL [180 µmol per L]); new or worsening heart failure; and the occurrence of vascular phenomena or emboli. Additional data included myocardial infarction, the need for cardiac surgery, length of hospitalization and death during hospitalization.
There were no significant differences in the type of valvular involvement or the distribution of organisms, with streptococcal species being most prevalent. There were also no significant differences noted in the frequency of fever, arrhythmias, renal failure, embolic events and valvular surgery. Mortality rates were higher for the elderly group, but not significantly so. Ten (16 percent) of the younger patients died, as did 12 (27 percent) of the older patients. There were also higher rates of myocardial infarction and altered mental status among the elderly patients, but these differences were not statistically significant. The only major difference between the two groups was duration of hospital stay, which averaged 42 days in the elderly group and 30 days in the younger group.
The authors conclude that age does not appear to be a predictor of mortality in patients with native valve endocarditis. Renal failure or cerebral emboli predicted poor outcomes in these patients, regardless of age. The authors believe that early and aggressive management of native valve endocarditis is indicated, regardless of patient age.
JEFFREY T. KIRCHNER, D.O.
Gagliardi JP, et al. Native valve infective endocarditis in elderly and younger adult patients: comparison of clinical features and outcomes with use of the Duke criteria and the Duke endocarditis database. Clin Infect Dis May 1998; 1165-8.
Ambient-Light Exposure and Retinopathy of Prematurity
Retinopathy of prematurity is a disease of the developing retinal vasculature that occurs in premature infants and is a leading cause of childhood blindness. The pathogenesis of this disorder is controversial but is believed to be environmental. High levels of inspired oxygen and ambient-light exposure cause an increase in free radicals in the retina, which may increase the incidence of retinopathy in premature infants. The effect of light on this disease has been debated for many years. Reynolds and colleagues performed a prospective, randomized, multicenter study to assess the effect of ambient light on the incidence of retinopathy in premature infants.
The study originally included 409 infants who had a birth weight of less than 1,251 g (2 lb, 12 oz), a gestational age at birth of less than 31 weeks and admission to a neonatal intensive care unit within 24 hours of birth. Children with a lethal congenital anomaly or a major congenital abnormality of one or both eyes were excluded from the study. The newborns were randomly assigned to a control group or a group that received light-reducing goggles within 24 hours after birth. The goggles reduced exposure to visible light by 97 percent and to ultraviolet light by 100 percent. Infants in the control group were exposed to the usual amount of light in the neonatal intensive care unit. The infants in the treatment group wore the goggles until 31 weeks after conception or four weeks after birth, whichever was longer. This length of time was chosen so that the goggles would be removed before it became necessary to identify children who had developed severe eye disease and would require surgical intervention.
After the goggles were removed, all infants had an initial ophthalmologic examination within seven days. They were then examined biweekly until their eyes were fully vascularized or, if retinopathy developed, until they reached 44 weeks' postconception age. A final ophthalmologic examination was performed on all infants six months after term. The ophthalmologists were blinded to treatment-group assignment.
During the study period, 46 infants died and two infants were lost to follow-up, leaving 188 infants in the treatment group and 173 in the control group. The baseline characteristics of both groups were essentially the same. The goggles were worn a median of 28 days. The mean light level measured adjacent to the infants' faces was 447 lux for the control group and 399 lux for the treatment group. There were 102 infants (54 percent) with confirmed retinopathy in the treatment group and 100 infants (58 percent) with confirmed retinopathy in the control group. At the six-month examination, myopia was diagnosed in 31 infants (19 percent) in the treatment group and 28 infants (19 percent) in the control group. All other ocular findings were similar between the two groups at the six-month visit.
The authors conclude that reduction in ambient-light exposure in the neonatal intensive care unit does not reduce the frequency of retinopathy of prematurity in newborns at high risk for this disorder.
JEFFREY T. KIRCHNER, D.O.
Reynolds JD, et al. Lack of efficacy of light reduction in preventing retinopathy of prematurity. N Engl J Med May 28, 1998;338:1572-6.
Diagnostic Evaluation of Patients with Palpitations
The complaint of heart palpitations is extremely common. While palpitations are rarely indicative of a serious cardiac problem, they are occasionally a manifestation of potentially life-threatening conditions. Zimetbaum and Josephson describe the presentation of common palpitations and offer a guide to diagnostic testing.
Heart palpitations are often described by patients in a variety of ways, including sensations of "flip-flopping" (premature atrial or ventricular contractions) or a rapid "fluttering" (atrial or ventricular arrhythmias) in the chest. Some people report a "pounding" in the neck. This sensation is most typical of a reentrant supraventricular arrhythmia.
Although palpitations are frequently associated with anxiety or panic attacks, they should not be attributed to psychiatric disorders until more serious causes have been excluded. In one study of 107 patients with electrophysiologically documented reentrant supraventricular tachycardia, 67 percent met the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria for panic disorder. In addition, there was a median time of 3.3 years from initial presentation to a physician and a definitive diagnosis.
Idiopathic ventricular tachycardias occur during periods of catecholamine excess, such as during exercise or emotional stress. This disorder often presents during the second or third decades of life as palpitations, dizziness or syncope. In patients with atrioventricular nodal tachycardia, the onset of symptoms may occur when they stand up straight after bending over, and symptoms often end when they lie down. Patients who experience dizziness, presyncope or true syncope often have a supraventricular arrhythmia. Their symptoms are caused by acute vasodilation, a rapid heart rate with low cardiac output, or both.
The evaluation of any patient who complains of palpitations should include a thorough history and physical examination, and a 12-lead electrocardiogram (ECG). The history should focus on the description of the palpitations as well as the patient's age at onset. The patient who has had symptoms since childhood is likely to have a supraventricular tachycardia. The physician may ask the patient to tap out the rhythm with his or her fingers, as it is critical that the patient give a detailed description of the symptoms. Providing examples of various cardiac rhythms to the patient is sometimes helpful. Palpitations described as abrupt in onset and termination are often caused by ventricular or supraventricular tachycardias.
It is unlikely that the physician will examine a patient during an episode of palpitations. Consequently, the cardiac examination should focus on detecting abnormalities such as the midsystolic click of mitral valve prolapse. Virtually every type of arrhythmia has been described with this disorder, and many patients have premature atrial or ventricular contractions. A holosystolic murmur heard along the left sternal border that increases when the Valsalva maneuver is performed suggests hypertrophic obstructive cardiomyopathy. Atrial fibrillation is a common cause of palpitations in patients with this disorder.
The ECG will help limit the differential diagnosis of palpitations in patients with normal sinus rhythm. For example, a short PR interval or delta waves suggest ventricular preexcitation and the substrate for supraventricular tachycardia (Wolff-Parkinson-White syndrome).
The authors recommend further diagnostic testing for the following patients: those whose initial evaluation suggests an arrhythmic cause for the palpitations; those at high risk for organic heart disease or any myocardial abnormality that can lead to serious arrhythmias (usually determined by history); and those who remain anxious and need an explanation for their symptoms. Ambulatory 24-hour Holter monitoring has been recommended. However, continuous-loop event recorders have proved more efficacious and cost-effective for the evaluation of palpitations. These devices are worn by the patient for two weeks (previously four weeks) and constantly record data. Unlike the Holter monitor, the information is only saved when the patient manually activates the device. When the monitor is activated, it saves the patient's cardiac rhythm for the preceding two minutes and the subsequent two minutes.
If, after the history, physical examination and 12-lead ECG, there is no evidence of heart disease and the palpitations are unsustained and well tolerated, ambulatory monitoring or reassurance is recommended. In patients whose evaluation suggests underlying heart disease and whose palpitations are unsustained, ambulatory monitoring is again recommended. If palpitations are sustained or poorly tolerated, electrophysiologic testing is recommended, even if there is no overt evidence of heart disease.
The authors have found that most outpatients evaluated for palpitations have a benign cause and will not require an extensive evaluation or medical treatment. In the few patients who need pharmacotherapy, the preferred treatment options are beta blockers or calcium channel blockers. Other antiarrhythmic medications are usually avoided because of the associated risks of proarrhythmia. Most patients found to have a supraventricular arrhythmia can be cured with radio-frequency ablation.
JEFFREY T. KIRCHNER, D.O.
Zimetbaum P, Josephson ME. Evaluation of patients with palpitations. N Engl J Med May 7, 1998;338:1369-73. *
"Tips from Other Journals" are written by the medical editors of American Family Physician.
Copyright © 1998 by the American Academy of Family Physicians.
This content is owned by the AAFP. A person viewing it online may make one printout of the material and may use that printout only for his or her personal, non-commercial reference. This material may not otherwise be downloaded, copied, printed, stored, transmitted or reproduced in any medium, whether now known or later invented, except as authorized in writing by the AAFP.
