Practice Guidelines
AAFP Releases Guidelines on Trial of Labor After Cesarean Delivery
The American Academy of Family Physicians (AAFP) has released an evidence-based clinical practice guideline on trial of labor after cesarean delivery (TOLAC). The recommendations replace the AAFP clinical recommendation on trial of labor versus elective repeat cesarean section for women with a previous cesarean section. The guideline, which was summarized in part in the August 2005 issue of Annals of Family Medicine, is available online at http://www.aafp.org/tolac.xml and is summarized in the accompanying table.
| AAFP Recommendations for TOLAC |
| 1. Women with one previous cesarean
delivery with a low transverse |
| 2. Patients desiring TOLAC should be counseled that their chance for a successful VBAC is influenced by the following factors: [SORT rating B] |
| Positive factors (increased likelihood of successful VBAC) |
| Maternal age less than 40 years Prior vaginal delivery (particularly prior successful VBAC) Favorable cervical factors Presence of spontaneous labor Nonrecurrent indication that was present for prior cesarean delivery |
| Negative factors (decreased likelihood of successful VBAC) |
| Increased number of prior cesarean deliveries Gestational age greater than 40 weeks Birth weight greater than 4,000 g (8 lb, 13 oz) Induction or augmentation of labor |
| 3. Prostaglandins should not be used for cervical ripening or labor induction, because their use is associated with higher rates of uterine rupture and decreased rates of successful vaginal delivery. [SORT rating B] |
| 4. TOLAC should not be restricted to maternity care facilities with available surgical teams present throughout labor, because there is no evidence that these additional resources result in improved outcomes.* [SORT rating C] At the same time, it is clinically appropriate that a management plan for uterine rupture and other potential emergencies requiring rapid cesarean delivery should be documented for each woman undergoing TOLAC. [SORT rating C] |
| 5. Maternity care professionals need to explore all issues that may affect a woman's decision (e.g., recovery time, safety). [SORT rating C] No evidence-based recommendation can be made about the best way to present the risks and benefits of TOLAC to patients. |
| TOLAC = trial of labor after cesarean delivery; VBAC = vaginal birth after cesarean delivery. *-"Maternity care facilities" refers to birthing facilities with labor and delivery units that have the capacity to provide appropriate monitoring and to provide a timely cesarean delivery when needed. A = consistent, good-quality, patient-oriented evidence; B = inconsistent or limited-quality patient-oriented evidence; C = consensus, disease-oriented evidence, usual practice, expert opinion, or case series. For information about the SORT evidence rating system, see page 1949 or http://www.aafp.org/afpsort.xml. Adapted from Wall E, Roberts R, Deutchman M, Hueston W, Atwood LA, Ireland B. Trial of labor after cesarean (TOLAC), formerly trial of labor versus elective repeat cesarean section for the woman with a previous cesarean section. The American Academy of Family Physicians. Leawood, Kan.: AAFP, 2005. |
The evidence for the updated guideline was supplied by the Agency for Healthcare Research and Quality (AHRQ), which used a rigorous process for systematic identification, retrieval, evaluation, and analysis of all relevant research. Studies that focused on nulliparous women or vertical, lower vertical, or classical cesarean incisions, and studies that did not differentiate by scar type were excluded, as were studies focusing on complicated deliveries (e.g., vaginal breech, preterm, multifetal, low birth weight) or patients with conditions such as gestational diabetes, human immunodeficiency virus infection, or preeclampsia. The quality of evidence was rated as good, fair, or poor.
The peer-reviewed, published results of the AHRQ evidence report were used to create the AAFP guideline, and an adapted version of the Strength of Recommendation Taxonomy (SORT) was used to rate the strength of the evidence. Because two years had passed since the original evidence review was published, the TOLAC panel conducted a systematic review of new evidence through March 2004 following the same procedure used for the AHRQ evidence report. The updated search yielded only seven studies that received a fair to good rating, and these studies did not address the same outcomes or have the same study focus. Accordingly, without a body of new evidence for any key question, the TOLAC panel determined that there was no support for any substantive change to the original report. Therefore, the original evidence report was used as the evidence source for this guideline.
The panel's objective was to provide an evidence-based clinical practice guideline for pregnant women with one previous cesarean delivery and their families, for the maternity care professionals attending their labor and delivery, for the maternity care facilities where they will labor and deliver, and for policy makers who care about trial of labor and maternity care for a woman. A maternity care facility is a birthing facility with a labor and delivery unit that has the capacity to provide appropriate monitoring and to provide a timely cesarean delivery when needed. A maternity care professional is someone who has privileges to manage normal labor and delivery.
There is fair to good evidence that 76 percent of women who attempt TOLAC are successful in having a vaginal birth. Labor induction or augmentation with oxytocin reduces the likelihood of success to 63 percent, and the use of prostaglandin ripening or induction further reduces the success rate to 51 percent. There is fair evidence that rates of maternal death and hysterectomy do not differ between elective repeat cesarean delivery and TOLAC, and that there is a small but significant increase in symptomatic uterine rupture in women attempting TOLAC (2.7 patients per 1,000 attempts). Studies of infection rates were limited by poor quality. The evidence for infant outcomes is poor; there may or may not be a slightly increased risk of infant death with TOLAC compared with elective repeat cesarean delivery. No relevant studies were found to address health status and health-related quality of life for women who attempted TOLAC or elective repeat cesarean delivery.
Based on this evidence, women with one previous cesarean delivery and a low transverse incision are candidates for and should be offered a trial of labor. [SORT rating A] Patients desiring TOLAC should be counseled that their chance for a successful vaginal birth after cesarean delivery is influenced by several factors (see accompanying table). [SORT rating B] Prostaglandins should not be used for cervical ripening or labor induction, because their use is associated with higher rates of uterine rupture and decreased rates of successful vaginal delivery. [SORT rating B]
Because there is no evidence that the provision of additional resources beyond those normally available to all laboring women improves maternal or neonatal outcomes for women attempting TOLAC, no recommendations could be made about restrictions on such deliveries. Because of concerns that efforts to limit the accessibility of TOLAC by requiring restrictive conditions during labor may force women to present late in labor, to place themselves at risk by lengthy travel to another facility during labor, or to submit to an unwanted cesarean delivery, TOLAC should not be restricted to facilities with available surgical teams present throughout labor, because there is no evidence that these additional resources result in improved outcomes. [SORT rating C] At the same time, it is clinically appropriate that a management plan for uterine rupture and other potential emergencies requiring rapid cesarean delivery should be documented for each woman undergoing TOLAC. [SORT rating C]
Finally, maternity care professionals need to explore all issues that may affect a women's decision (e.g., recovery time, safety). [SORT rating C] No evidence-based recommendation can be made about the best way to present the risks and benefits of TOLAC to patients.
Practice Guideline Briefs
CDC Reports on Illnesses in Hurricane Katrina Evacuees and Relief Workers
Hurricane Katrina struck the U.S. Gulf Coast on August 29, 2005, resulting in extensive structural damage and severe flooding from breached levees in and around New Orleans. In the four weeks after the hurricane made landfall, a total of 7,508 illnesses and injuries were reported, according to the Centers for Disease Control and Prevention (CDC). Reports on illnesses in hurricane evacuees and relief workers were published in the September 23, September 30, October 7, and October 14, 2005, issues of Morbidity and Mortality Weekly Report (http://www.cdc.gov/mmwr).
Influenza Vaccination Recommendations The Centers for Disease Control and Prevention recommends that displaced persons from Hurricane Katrina who are six months and older and are living in crowded group settings be administered influenza vaccine. Children eight years and older should be given two doses at least one month apart unless they have a documented record of a previous dose of influenza vaccine, in which case they should receive one dose of vaccine. |
Of the 6,167 illnesses and injuries in which disposition status was known, five persons died and 552 (9.0 percent) were admitted to hospitals. Among those injured, 42 had intentional injuries (i.e., self-inflicted or violent), seven of whom were victims of assault. The proportion of ill patients evaluated for acute respiratory infection (ARI) increased from September 8 to September 25, when data were analyzed. Among the 505 patients with ARI, 371 (73.5 percent) had cough, 62 (12.3 percent) had shortness of breath, and 60 (11.9 percent) had fever. A total of 23 persons with ARI (4.6 percent) were admitted to a hospital.
Rash illnesses also increased over time. Relief workers were significantly more likely than residents to be seen for a rash (odds ratio [OR], 1.7). These rashes were noninfectious; they were classified as prickly heat, arthropod bites, and the abrasive effects of wet clothing and moist skin. Motor vehicle crashes were responsible for 145 of the 2,018 injuries (7.2 percent); motor vehicle crashes accounted for a smaller proportion of injuries among relief workers (5.0 percent) than among residents (9.2 percent; OR, 0.55). As of September 25, 14 cases of carbon monoxide poisoning had been detected, and 27 persons were exposed to other toxic substances (e.g., diesel fuel, contaminated water, cleaning agents).
norovirus outbreak in evacuees
During the week after Hurricane Katrina made landfall, an estimated 240,000 persons, mostly from Louisiana, evacuated to Houston. On August 31, an estimated 24,000 evacuees were sheltered temporarily at facilities in Reliant Park, a sports and convention complex. On September 2, physicians and public health workers noted a substantial number of adults and children with symptoms of acute gastroenteritis at the medical clinic in Reliant Park.
Approximately 6,500 of the estimated 24,000 evacuees visited the Reliant Park medical clinic between September 2 and September 12, and 1,169 persons (18 percent) reported symptoms of acute gastroenteritis. The number of persons with acute gastroenteritis peaked on September 5, when 211 persons reported symptoms, and cases declined slowly thereafter. A total of 511 patients (44 percent) with acute gastroenteritis symptoms had diarrhea only, 342 (29 percent) reported vomiting only, and 316 (27 percent) reported diarrhea and vomiting. In addition, health care professionals, police officers, and volunteers who had direct contact with patients reported acute gastroenteritis symptoms, suggesting substantial secondary spread, presumably by person-to-person contact or fomite transmission. The number of hospitalizations was unknown; no deaths were reported.
Stool samples (i.e., rectal swabs or bulk stools) were collected for laboratory diagnosis of bacterial, parasitic, and viral enteropathogens. Norovirus was confirmed in one half of stool samples from 44 patients tested by reverse transcription-polymerase chain reaction; no other enteropathogen was identified.
At the beginning of the outbreak, health care professionals implemented extensive infection-control measures. Patients with acute gastroenteritis and dehydration were rehydrated in a separate observation area reserved for patients with suspected infectious illness and then transferred to an isolation area for at least 48 hours after vomiting and diarrhea ended. In addition, alcohol-based gel hand sanitizers were distributed throughout the facilities and near lavatories, and a bank of portable sinks was installed inside the medical clinic. Medical staff, disaster relief workers, volunteers, and evacuees were alerted to the heightened need for proper handwashing techniques. Despite these timely interventions, the outbreak continued for more than one week but declined before the evacuees vacated Reliant Park in late September 2005.
vibrio illnesses after hurricane katrina
In the two weeks after Hurricane Katrina made landfall, 22 new cases of Vibrio illness were identified and five Vibrio-related deaths were reported. These illnesses were caused by Vibrio vulnificus, Vibrio parahaemolyticus, and nontoxigenic Vibrio cholerae. These organisms are unlikely to cause outbreaks from person-to-person transmission. No cases of toxigenic V. cholerae serogroups O1 or O139, the causative agents of cholera, were identified. These illnesses underscore the need for heightened clinical awareness, appropriate culturing of specimens from patients, and empiric treatment of illnesses (particularly those associated with wound infections) caused by Vibrio species.
Eighteen wound-associated Vibrio cases were reported in residents of Mississippi and Louisiana; in persons displaced from Louisiana to Texas, Arkansas, and Arizona; and in one person displaced from Mississippi to Florida. Speciation was performed in clinical laboratories for 17 of the wound-associated cases; 14 were V. vulnificus, and three were V. parahaemolyticus. Five patients with wound-associated Vibrio infections died; three deaths were associated with V. vulnificus infection, and two were associated with V. parahaemolyticus infection.
An underlying condition that may have increased the risk for severe Vibrio illness was reported in
13 (72 percent) of the patients with wounds; these conditions included heart disease, diabetes mellitus, renal disease, alcoholism, liver disease, peptic ulcer disease, immunodeficiency, and malignancy.
Four persons were reported with non-wound-associated Vibrio infections (two in Mississippi, one in Louisiana, and one displaced from Louisiana to Arizona). Information on the Vibrio species and clinical illness was available for two of these patients; the species were nontoxigenic V. cholerae isolated from patients with gastroenteritis. No deaths were reported in patients with non-wound infections.
After natural disasters such as Hurricane Katrina, the risk for illness related to infectious diseases is a public health concern. The CDC findings underscore the need for prompt recognition and management of Vibrio wound infections by health care professionals.
V. vulnificus wound infections can begin as redness and swelling at the site of the wound and rapidly progress in patients at high risk to cause systemic illness, including sepsis. V. vulnificus typically causes a severe and life-threatening illness characterized by fever and chills, decreased blood pressure (septic shock), and blood-tinged blistering skin lesions (hemorrhagic bullae). Persons with chronic liver disease or immunocompromising conditions are particularly at risk for severe V. vulnificus infections.
V. parahaemolyticus typically causes gastroenteritis after consumption of contaminated shellfish. Less commonly, V. parahaemolyticus causes wound infections that are generally less severe than V. vulnificus wound infections. However, in persons with liver disease or immunocompromising conditions, V. parahaemolyticus wound infections can cause death.
Nontoxigenic V. cholerae primarily causes gastroenteritis, but unlike toxigenic V. cholerae O1 or O139, nontoxigenic V. cholerae does not cause epidemics. Illness caused by this organism ranges in severity from mild diarrhea to severe watery diarrhea. Fever and bloody diarrhea typically are not observed. Immunocompromised persons and persons with liver disease can experience a more severe illness, including fever, chills, and septic shock. This organism rarely has been reported to cause wound infections.
Vibrio infections are diagnosed by culture of wound, blood, or stool specimens. For stool specimens, a selective media of thiosulfate-citrate-bile salts-sucrose agar (TCBS) is recommended. If there is clinical suspicion of enteric Vibrio infection, the laboratory should be notified so that TCBS media will be used.
Persons working in hurricane-damaged areas, especially in areas with standing brackish water, should wear boots and other protective gear to prevent wounds and to prevent exposure of broken skin to contaminated water. To prevent Vibrio infections, persons with open wounds or broken skin should avoid contact with brackish water or seawater, especially if they have preexisting liver disease or other immunocompromising conditions. Injury prevention is especially important in these high-risk populations. Healthy persons are at much lower risk for Vibrio infection. In areas where floodwaters have receded and surfaces are dry, Vibrio should not be a concern because the organism is killed rapidly by drying.
To reduce the risk for Vibrio wound infection, persons should wash all wounds that have been exposed to sea or brackish waters with soap and clean water as soon as possible and seek medical care for any wound that appears infected. Physicians should be vigilant for Vibrio infection in hurricane evacuees, particularly in patients with infected wounds and especially if the patients are in a high-risk group. If V. vulnificus infection is suspected, antimicrobial therapy should be started immediately; prompt treatment can improve survival. Antimicrobials effective against Vibrio infections include doxycycline (Vibramycin), third-generation cephalosporins (e.g., ceftazidime [Fortaz]), fluoroquinolones, and aminoglycosides. Wound infections also should be treated with aggressive attention to the wound site; amputation of the infected limb is sometimes necessary. For Vibrio gastroenteritis that is mild and self-limited, treatment with oral rehydration usually is sufficient. Antimicrobial therapy might be helpful for patients with severe or prolonged diarrhea.
|
|
Copyright © 2005 by the American Academy of Family Physicians. |
