Neonatal jaundice, animal-induced injuries, and immunizations

The authors describe recent developments in three areas of pediatrics commonly encountered by the office practitioner. First, clinical assessment of jaundice remains critically important as "early discharge" of newborns continues. Practitioners constantly balance clinical realities with an evidence-based approach in the management and follow-up of neonatal hyperbilirubinemia. Second, given the frequent exposure of children to animals, a thorough understanding of animal bites, pet-borne infections, and rabies prophylaxis is essential for every pediatrician. Finally, immunization status remains one of our leading health indicators. Recent changes in the routine immunization schedule and a renewed emphasis on vaccine safety provide insight into the future direction of vaccinology.

Quality of analgesia when air versus saline is used for identification of the epidural space in the parturient

BACKGROUND AND OBJECTIVES

Identification of the epidural space is often performed using the loss-of-resistance technique (LOR), commonly with air or saline. The effect of air or saline on the quality of labor epidural analgesia has not been adequately studied.

METHODS

Women who requested labor epidural analgesia were randomly assigned to 1 of 2 groups depending on the syringe contents used for the LOR technique and injected into the epidural space. In the air group (n = 80) the anesthesiologist used 2 mL of air, and in the saline group (n = 80) the anesthesiologist used 2 mL of 0.9% saline. After LOR was obtained, a multiorifice epidural catheter was threaded 5 cm into the epidural space and 13 mL of bupivacaine 0.25% was administered in divided doses. The success of the epidural block was determined by asking the patient if she required additional medication 15 minutes later. The occurrence of paresthesias and intravascular or subarachnoid catheters was noted.

RESULTS

In the air group, 36% of patients requested additional pain medication, and in the saline group 19% requested additional medication (P =.022). We were not able to find a statistically significant difference between groups in the incidence of paresthesias (42% air v 51% saline), intravascular catheters (5% air v 8% saline), or subarachnoid catheters (0 in both groups).

CONCLUSIONS

Using 0.9% saline for the LOR technique is associated with better analgesia as compared with air for labor analgesia, and this advantage should be considered when selecting the syringe contents for the LOR technique.

Neonatal jaundice, animal-induced injuries, and immunizations

The authors describe current investigation and most recent developments in three areas of pediatrics commonly faced by the office practitioner. The impetus of earlier newborn discharge places increased emphasis on pediatricians to accurately predict clinically significant jaundice. A better understanding of the pathophysiology of breastfeeding and breast milk jaundice, and the realization that Gilbert's syndrome may play a greater role in neonatal jaundice, only help confirm that the story of neonatal jaundice is still unfolding. Animal (particularly canine) bite injuries continue to be the most common animal-induced injuries, and a thorough review of appropriate antibiotic treatment and rabies prophylaxis guidelines are essential for the pediatric practitioner. During the past year, several major changes involving the use of rotavirus, pneumococcal, polio, meningococcal, and hepatitis A vaccines have taken place, which will have marked impact not only on pediatric office practice, but also on society as a whole.

Impact of an encounter-based prompting system on resident vaccine administration performance and immunization knowledge

OBJECTIVES

To evaluate an encounter-based immunization prompting system on resident performance in administering vaccines and knowledge of immunization guidelines.

DESIGN/METHODS

Prospective randomized, controlled trial. Subjects were first- and second-year pediatric residents in a hospital-based continuity clinic. The intervention group received manual prompts of immunizations due. Postclinic chart review compared immunizations due with those administered. Acceptable and unacceptable reasons for not administering vaccines were assigned. Resident knowledge was measured by a 70-item examination.

RESULTS

The intervention group had significantly less missed opportunities/vaccine administration errors (11.4% vs 21.6%). The most common reason for unacceptable errors in the intervention group: vaccine was given too early; in the control group: vaccine was postponed to next visit. Pre- and postintervention knowledge scores were similar: intervention group (75.5% vs 80.7%, control group; 76.5% vs 81.3%).

CONCLUSION

An immunization prompting system in a hospital-based pediatric resident continuity clinic reduced missed opportunities/vaccine administration errors without significantly impacting resident knowledge of immunization guidelines.immunization schedule, vaccination, immunization, prompting systems, resident education.

Direct measurement of LDL-C in children: performance of two surfactant-based methods in a general pediatric population

OBJECTIVES

Several pediatric advisory groups have recommended selective screening for dyslipidemia in children. Low-density lipoprotein cholesterol (LDL-C) is measured clinically with the Friedewald calculation in fasting samples. Nonfasting measurement of LDL-C would be clinically useful in children.

DESIGN AND METHODS

In the present study, we examine the performance of two surfactant-based direct LDL-C assays in paired samples, fasting and nonfasting, from 100 children.

RESULTS

LDL-C in the fasting state was significantly lower with the Friedewald estimation: 2.43 +/- 0. 61 mmol/L, N-geneous (Genzyme Corp.) direct LDL-C: 2.30 +/- 0.59 mmol/L, and Roche (Roche Diagnostics) direct LDL-C: 2.32 +/- 0.57 mmol/L than with ultracentrifugation-dextran-sulfate-Mg(2+) precipitation (UC-DS): 2.47 +/- 0.64 mmol/L. Moreover, there was increased negative bias using nonfasting samples with N-geneous: 2. 25 +/- 0.56 mmol/L and Roche: 2.26 +/- 0.56 mmol/L compared with fasting UC-DS. Correlation with US-DS was highest for Friedewald (r = 0.974) and fasting N-geneous (r = 0.973), and lowest with nonfasting N-geneous (r = 0.849) and Roche in fasting (r = 0.891) and nonfasting samples (r = 0.747). The sensitivity at LDL-C concentration of 2.85 mmol/L for the two direct methods when either fasting or nonfasting samples were used, was lower than that obtained with Friedewald.

CONCLUSION

Overall, these direct LDL-C assays demonstrated limited utility in screening children but may be useful in the management of lipid disorders.

Neonatal jaundice, animal-based injuries, and immunizations

The authors describe current investigation in three areas of pediatrics commonly faced by the office practitioner. Despite the fact that changes in medical practice and in patient demographics have resulted in the reemergence of severe hyperbilirubinemia and bilirubin encephalopathy, clinical assessment and evaluation of discharge bilirubin levels may help predict those infants at greatest risk. Progress in the use of inhibitors of bilirubin production may eventually decrease the need for phototherapy. Although dog-associated injuries continue to affect children disproportionately, additional attention to anticipatory guidance may prove beneficial. The practice of routine immunization has reshaped our view of pediatric illness. The development of pneumococcal, meningococcal, and rotaviral vaccines will alter significantly the prevalence of common pediatric infectious disease. However, with the advent of additional vaccines, attention to pain control will take on increasing urgency.

The scope of unmet maternal health needs in pediatric settings

OBJECTIVE

Previous work has focused attention on the prevalence of specific maternal health problems known to affect children, such as smoking or depression. However, the cumulative health burden experienced by mothers and the potential for a practical pediatric health services response have not been examined. The aims of this study were to characterize: 1) the prevalence and cumulative burden of maternal health behaviors and conditions, 2) maternal access to a source of comprehensive adult primary care, and 3) maternal perceptions of a pediatric role in screening and referral.

METHODS

We surveyed 559 consecutive women bringing a child 18 months of age or less to one of four pediatric primary care sites between July 1996 and May 1997. The pediatric sites included one outpatient program in an academic hospital, one in a community health center, and two in-staff model practices of a managed care organization (these last two were combined for analysis). The self-administered questionnaire contained previously validated questions to assess health behaviors and conditions (smoking, alcohol abuse, depression, violence, risk for unintended pregnancy, serious illness, self-reported health) and access to care (regular source, regular provider, health insurance, care delayed or not received). Maternal attitudes toward a pediatric role in screening and referral were also elicited.

RESULTS

In the three settings, response rates ranged from 75% to 84%. The average age of the women ranged from 25.1 to 32. 1 years and the average age of the children ranged from 6.5 to 8.0 months. Across the settings, the percentage of women reporting at least one health condition (66%-74%) was similarly high, despite significant demographic differences among sites. Many women reported more than one condition (31%-37%); among all women who smoked, 33% also screened positive for alcohol abuse, 31% for emotional or physical abuse, and 48% for depression. Access to comprehensive adult primary care was variable with 23% to 58% of women reporting one or more barriers depending on the site. Across all sites, >85% of mothers reported they would "not mind" or "would welcome" a pediatric role in screening and referral.

CONCLUSIONS

Two-thirds of women bringing their children for pediatric care had health problems regardless of the site of care. Many women also reported substantial barriers to comprehensive health care. Most women reported acceptance of a pediatric role in screening and referral. Given the range and depth of maternal health needs, strategies to connect or reconnect mothers to comprehensive adult primary care from a variety of pediatric settings should be explored.

Neonatal jaundice, animal-based injuries, and immunizations

This review presents in a clinically relevant context the past year's investigations in three areas of pediatrics that commonly face the office-based pediatric provider. Although transcutaneous quantification of jaundice may help discern which patients warrant further evaluation, thereby saving patients pain and expense, this technology has not yet significantly changed clinical management of the hyperbilirubinemic infant. A brief overview of animal bites demonstrates that although most are innocuous, proper treatment of these potentially serious injuries is critical in preventing further complications. The number of immunizations given in the first 2 years of life has increased, and although new combination vaccines may eventually simplify the schedule, persistent vigilance is more important than ever to avoid delays in vaccine administration.

Treatment of incomplete analgesia after placement of an epidural catheter and administration of local anesthetic for women in labor

BACKGROUND

Approximately 15% of women still have pain after placement of an epidural catheter and administration of local anesthetic for labor analgesia. Two techniques frequently used to treat this pain were compared: (1) withdrawal of the catheter 1 cm and repeated dosing with additional local anesthetic, and (2) repeated dosing with additional local anesthetic without any catheter manipulation.

METHODS

Fifteen minutes after placement of a multiple-orifice epidural catheter 5 cm into the epidural space and administration of 13 ml 0.25% bupivacaine to the parturient in labor, the adequacy of analgesia was assessed. All women who had incomplete analgesia were randomized (first intervention) to receive an additional 5 ml 0.25% bupivacaine (local-anestheticonly group) or to receive 5 ml 0.25% bupivacaine after first withdrawing the epidural catheter 1 cm (catheter-manipulation group). If after 15 min the woman still had pain, then (second intervention) the catheter was withdrawn 1 cm and an additional 5 ml 0.25% bupivacaine was administered to the local-anesthetic-only group, whereas 5 ml 0.25% bupivacaine was given to the catheter-manipulation group without further catheter manipulation. The success rate of the second intervention was assessed 15 min later.

RESULTS

Seventy-eight women were enrolled in the study, 39 to each group. In the local-anesthetic-only group, 29 (74%) women were successfully treated with the first intervention and the remaining 10 (100%) were successfully treated with the second intervention. In the catheter-manipulation group, 30 (77%) were successfully treated with the first intervention and 7 (100%; 2 patients were not studied because of investigator error) were successfully treated with the second intervention (P=NS).

CONCLUSIONS

Administration of additional local anesthetic without first withdrawing the epidural catheter will effectively treat most women for whom analgesia is incomplete after the placement of an epidural catheter during labor.

Subhypnotic doses of propofol do not relieve pruritus induced by intrathecal morphine after cesarean section

The purpose of this study was to determine whether subhypnotic doses of propofol effectively relieve pruritus in women who received intrathecal morphine for postoperative analgesia after cesarean delivery. Twenty-nine women who developed pruritus after undergoing an elective cesarean section and receiving intrathecal morphine (0.25 mg) for postoperative analgesia were enrolled in this randomized, prospective, double-blind study. The women were randomly assigned to receive either 1 mL of propofol (n = 17) or 1 mL of placebo (n = 12) I.V. Pruritus was evaluated 5 min after treatment. In the absence of successful treatment, the women received another 1 mL of the same drug. Pruritus was again evaluated 5 min after the second dose. We found that pruritus was successfully treated twice in the propofol group and once in the placebo group (P = not significant). The antipruritic action of propofol lasted for up to 6 h in one woman and 15 min in the other. The one success in the placebo group lasted for 15 min. We conclude that the success rate of propofol in treating pruritus in women who received intrathecal morphine for postoperative analgesia after cesarean delivery is not significantly different from that of placebo.

IMPLICATIONS

Pruritus is a common and bothersome side effect of neuraxial opioids after cesarean section. Subhypnotic doses of I.V. propofol (10 mg) have been used to treat pruritus caused by neuraxial opioids. In this prospective, randomized, double-blind study, we found that propofol does not relieve pruritus in women who underwent cesarean section and received intrathecal morphine sulfate (0.25 mg) for postoperative pain relief.

The ability of the Haemonetics 4 Cell Saver System to remove tissue factor from blood contaminated with amniotic fluid

The purpose of this study was to determine whether functionally active tissue factor could be removed from blood contaminated with amniotic fluid (AF) after processing through a Haemonetics 4 Cell Saver System (Haemonetics Corporation, Braintree, MA). In Phase I, AF was collected from 29 women undergoing cesarean section. Nine experiments were performed. Forty-milliliter aliquots of pooled AF were mixed with 125 mL of packed red blood cells and processed in the Cell Saver. In Phase II, all the blood and AF lost at cesarean section was collected and processed through the Cell Saver. Pre- and postwash specimens were collected and analyzed for total tissue factor concentration and the concentration of functionally active tissue factor. In Phase I, total tissue factor concentration was reduced by 89%, and the concentration of active tissue factor was reduced to 0 after processing. In Phase II, no tissue factor was detected after processing through the Cell Saver. We have demonstrated the ability of the Haemonetics 4 Cell Saver System to remove tissue factor activity from blood contaminated with AF.

IMPLICATIONS

Hemorrhage after childbirth may require massive transfusion. If the patient's own blood can be collected and given back to the patient, this may avoid the use of regular banked blood. Amniotic fluid, which may mix with blood lost after delivery, contains tissue factor, a substance that may activate the coagulation system and cause further bleeding. The authors found that the Haemonetics 4 Cell Saver System (Haemonetics Corporation, Braintree, MA), which collects and washes blood, can remove tissue factor from blood contaminated with amniotic fluid.

Dose titration study of live attenuated varicella vaccine in healthy children. Pennridge Pediatric Associates

To approximate the effect of prolonged storage on safety and immunogenicity, healthy children were given a single dose of the currently marketed live attenuated varicella vaccine (3625 pfu) or of a partially heat-inactivated vaccine (1125 or 439 pfu). The 3 doses had similar antigen content (attenuated plus inactive virus particles). The vaccine was well tolerated. No significant differences in adverse reactions were observed. Although the seroconversion rates were excellent at each dose (> or = 98%), the higher doses resulted in significantly greater geometric mean antibody titers at 6 weeks (10.5 and 10.6 ELISA U/mL) compared with the 439 pfu dose (5.7 ELISA U/mL), P < or = .01. One year after immunization, differences in antibodies were similar to the 6-week postimmunization results. Results indicate that until the date of expiry, the vaccine's immunogenicity will be preserved and there will be no clinically important changes in type or frequency of adverse events.

Information and concerns about obstetric anesthesia: a survey of 320 obstetric patients

This study was undertaken to assess women's knowledge and concerns about obstetric anesthesia and to determine if they perceive a need for an anesthesia interview before the onset of labor. A 17 item questionnaire was distributed to 407 women on postpartum day one. The women were questioned about their knowledge, anxiety and concerns regarding obstetric anesthesia. The questionnaire was completed by 320 women, 57% of whom were Caucasian and 28% of whom had some postgraduate education. Most of the women (74%) had either a regional or general anesthetic for their delivery and 86% of the women admitted to having some anxiety about anesthesia. Although 82% of the women attempted to obtain information about anesthesia before labor, 28% did not feel adequately informed. The majority (59%) of the women would have wanted a preoperative visit with an anesthesiologist before labor. These results illustrate that most women are anxious about obstetric anesthesia and do not feel adequately prepared. Efforts at educating women about obstetric anesthesia would be welcomed by them and methods to accomplish this goal are discussed.

Comparison of diphtheria-tetanus-two component acellular pertussis vaccines in United States and Japanese infants at 2, 4, and 6 months of age

OBJECTIVE

We compared the diphtheria and tetanus toxoids and bicomponent acellular pertussis vaccine (DTaP) responses in Japanese and United States infants.

DESIGN

This was a double-blind, comparative study.

SETTING

Private pediatric practices in Japan and the U.S. participated.

SUBJECTS

One hundred eighty-nine healthy 2-month old infants were tested.

INTERVENTIONS

Infants were immunized at 2, 4, and 6 months of age. The Japanese formulation (DTaP-J) contained 20 micrograms of pertussis toxin (PT) and 20 micrograms of filamentous hemagglutinin (FHA); the U.S. formulation (DTaP-US) contained 23.4 micrograms of each antigen. Parents used a standard form to record average adverse experiences. Serum was obtained before the first immunization, 2 months after the second immunization, and 1 month after the third immunization.

MEASUREMENTS

Differences in DTaP-J and DTaP-US were evaluated in Japanese infants immunized subcutaneously (s.c.). Differences due to ethnicity and to route of administration were compared in U.S. infants immunized with DTaP-US s.c. or intramuscularly (i.m.). An indirect enzyme-linked immunosorbent assay was used to determine immunoglobulin G antibody responses to PT, FHA, and tetanus toxoid. Neutralizing antibody to PT was measured by a Chinese hamster ovary call assay. Diphtheria antitoxin was assayed by serum neutralization on VERO cells.

RESULTS

Statistical differences (P < .05) in adverse events included less fatigue after immunization with DTaP-US compared with DTaP-J. Erythema of more than 2.5 cm was more frequent, but erythema less than 2.5 cm was less frequent in Japanese infants compared with U.S. infants. Fewer Japanese infants were febrile ( > 38 degrees C), tired, or irritable. Subcutaneous immunization resulted in a greater frequency of erythema and induration. The DTaP-US resulted in an equivalent response to PT and a greater response to FHA. More Japanese infants demonstrated at least a fourfold response over preimmunization antibody values to FHA. In U.S. infants, antibody responses to the contained pertussis antigens were equivalent after i.m. and s.c. administration. Compared with Japanese infants receiving DTaP-J s.c., U.S. infants receiving DTaP-US i.m. had equivalent responses to PT and a greater response to FHA.

CONCLUSIONS

United States infants receiving an i.m. injection of a U.S. -produced bicomponent DTaP vaccine produced antibody responses to the contained pertussis antigens at least equal to those of Japanese infants receiving a similar bicomponent DTaP vaccine shown to be effective in older Japanese children.

Reactogenicity and immunogenicity of a three-component acellular pertussis vaccine administered as the primary series to 2, 4 and 6 month old infants in the United States

Five hundred and fifty-seven infants received either an acellular pertussis (DTaP) vaccine containing pertussis toxoid (PT), filamentous hemagglutinin (FHA) and pertactin (PRN) or one of two commercially available whole-cell pertussis (DTP) vaccines at 2, 4 and 6 months. One month after the third immunization, IgG antibody values to pertussis toxoid, filamentous hemagglutinin and PRN were significantly greater following DTaP than either DTP (P < 0.05). When reactions within 48 h after all three doses of vaccine were combined, fever 101 degrees, > or = moderate fussiness, > or = moderate pain, swelling 10 mm, and erythema 10 mm occurred less often after DTaP compared with DTP-Connaught (P < 0.001). The same adverse events were also less after DTaP compared with DTP-Lederle (P < 0.05), except for erythema 10 mm. This three-component DTaP vaccine produced fewer adverse events and greater antibody values to PT, FHA and PRN in comparison with either licensed DTP vaccine when given as the primary series.

The optimal distance that a multiorifice epidural catheter should be threaded into the epidural space

Complications can occur during epidural placement for women in labor. As many as 23% of epidural anesthetics may not provide satisfactory analgesia. The cause of this may be technical. This study was undertaken to determine the optimal distance that a multiorifice catheter should be threaded into the epidural space to maximize analgesia and minimize complications. One hundred women in labor were enrolled in this prospective, randomized, and double-blind study. Patients were randomly assigned to have the epidural catheter threaded 3, 5, or 7 cm into the epidural space. After placement of the catheter and administration of a test dose with 3 mL of 0.25% bupivacaine, an additional 10 mL of 0.25% bupivacaine was administered in two divided doses. Fifteen minutes later, the adequacy of the analgesia was assessed by a blinded observer. We found that catheter insertion to a depth of 7 cm was associated with the highest rate of insertion complications while insertion to a depth of 5 cm was associated with the highest incidence of satisfactory analgesia. For women in labor who require continuous lumbar epidural anesthesia, we recommend threading a multiorifice epidural catheter 5 cm into the epidural space.

Comparison of a three-component acellular pertussis vaccine with a whole-cell pertussis vaccine in 4- through 6-year-old children. Elmwood Pediatric Associates, Pennridge Pediatric Associates

OBJECTIVE

To compare the safety and immunogenicity of a three-component acellular pertussis (DTaP) vaccine containing pertussis toxin (PT), filamentous hemagglutinin (FHA), and pertactin with whole-cell pertussis (DTwP) vaccine in 4- through 6-year-old children.

PARTICIPANTS

One hundred seventy-two healthy 4- through 6-year-old children previously immunized with the DTwP vaccine at or near 2, 4, 6, and 18 months of age.

INTERVENTIONS

Prevaccination serum samples were obtained on all study participants. One hundred twelve children received 0.5 mL of the DTaP vaccine intramuscularly. Fifty-three children received 0.5 mL of a commercially available DTwP vaccine intramuscularly. Approximately 30 days following vaccination, additional serum samples were obtained.

MEASUREMENTS

Parents monitored adverse reactions for 7 days following immunization. Significantly fewer children in the DTaP group reported temperatures of greater than 38.1 degrees C and an area of redness of more than 10 mm and moderate-to-severe pain at the injection site.

RESULTS

Antibody responses to PT, FHA, pertactin, and diphtheria and tetanus toxoids were measured by enzyme-linked immunosorbent assay. Among subjects who were seronegative prior to vaccination, response was defined as the detection of antibody levels following vaccination; among children with detectable antibody levels prior to vaccination, in terms of the rise in antibody titers. Data using a twofold and a fourfold rise in antibody titers as criteria to define response were evaluated. Children in the DTaP group had significantly greater increases in geometric mean titers of antibodies against PT, FHA, and pertactin. Over 90% of the DTaP group responded to PT, FHA, and pertactin according to the criteria of both the twofold and the fourfold rise in antibody titers. Significantly fewer of the DTwP group responded to PT, FHA, and pertactin with at least a fourfold rise in antibody titers. When analyzing subjects with at least a twofold increase in antibody titers, a statistically significant difference remained in regard to anti-FHA antibodies. All study subjects had protective antibody titers against diphtheria and tetanus toxoids following vaccination. The geometric mean titer of antibodies against tetanus was significantly greater in the DTwP group than in the DTaP group.

CONCLUSION

The three-component DTaP vaccine administered as a booster immunization in 4-through 6-year-old children produced less fever and less redness and pain at the injection site than the DTwP vaccine and was as immunogenic as the DTaP vaccine.

Comparison of a three-component acellular pertussis vaccine with a whole-cell pertussis vaccine in 15- through 20-month-old infants

OBJECTIVE

To compare the immunogenicity and reactogenicity of a diphtheria and tetanus toxoids and three-component acellular pertussis vaccine (DTaP) with a diphtheria and tetanus toxoids and whole-cell pertussis vaccine (DTwP) when administered as a booster dose to infants 15 through 20 months of age.

DESIGN

Randomized, double-blind, comparative study.

SETTING

Three pediatric practices (two private; one hospital-based).

PARTICIPANTS

One hundred and sixty-five healthy 15- through 20-month old infants. SELECTION PROCEDURES AND INTERVENTIONS: Infants were randomly assigned in a 2:1 ratio to receive vaccine from a single lot of DTaP or from commercially available DTwP. DTaP contained 25 micrograms of pertussis toxoid, 25 micrograms of filamentous hemagglutinin, 8 micrograms of pertactin (69-kilodalton outer membrane protein), 25 flocculating units of diphtheria toxoid, and 10 flocculating units of tetanus toxoid per 0.5-mL dose. DTwP contained one half the concentrations of diphtheria and tetanus toxoids compared with DTaP and a pertussis component with a potency of 4 U/0.5-mL dose. Serum samples were obtained on the day of immunization and 4 weeks later. Adverse reactions were recorded by parents for 7 days after immunization. An interval history was obtained 4 weeks after immunization.

MEASUREMENTS AND RESULTS

IgG antibody to pertussis toxoid, filamentous hemagglutinin, pertactin, diphtheria toxoid, and tetanus toxoid was measured by an indirect enzyme-linked immunosorbent assay (ELISA) method. One month after immunization, the geometric mean antibody levels after DTaP compared with DTwP were: pertussis toxoid, 70.6 vs 28 ELISA U/mL (P = .003); filamentous hemagglutinin, 183.4 vs 43 ELISA U/mL (P < .001); pertactin, 216 vs 49.9 ELISA U/mL (P < .001); diphtheria, 14.1 vs 14.9 IU/mL (P = .74); and tetanus, 11.9 vs 14.8 IU/mL (P = .089). After immunization with DTaP, most local and systemic adverse experiences were significantly fewer compared with DTwP (P < .05).

CONCLUSIONS

This three-component DTaP vaccine demonstrates significantly greater immune responses to pertussis toxoid, filamentous hemagglutinin, and pertactin, equivalent immune responses to diphtheria and tetanus toxoids, and significantly less reactogenicity compared with a licensed DTwP.

Clinical survey of natural varicella compared with breakthrough varicella after immunization with live attenuated Oka/Merck varicella vaccine

OBJECTIVE

To prospectively characterize varicella occurring in children previously immunized with a live attenuated varicella vaccine (breakthrough varicella) through daily observation by medical personnel and to compare it with natural varicella followed in the same manner.

DESIGN

A blinded clinical survey.

SETTING

Four pediatric practices (two private; two hospital-based).

PARTICIPANTS

Healthy 12-month-old through 17-year-old children with chickenpox were studied; 92 had natural varicella and 58 had breakthrough varicella. SELECTION PROCEDURES AND INTERVENTIONS: Study personnel, unaware of vaccination status, documented the clinical characteristics of each patient in the office or at the patient's home each day from enrollment until the day after the total number of lesions increased less than 10%. A standard form documenting number and description of lesions, temperature, duration of illness, and associated clinical complaints was completed each day by the same study personnel. Acute and convalescent sera were obtained on breakthrough cases.

MEASUREMENTS AND RESULTS

Antibody to varicella-zoster virus was measured by the glycoprotein-based enzyme-linked immunosorbent assay. Of those with sera available, 85% were serologically confirmed. Eighty-seven percent of enrollees had a known exposure to chickenpox, with at least two thirds of each group having a greater than 4-hour or a household exposure. The numbers of total and vesicular lesions were significantly higher in the natural varicella group, regardless of exposure status (P = .021 to < .001). The group with breakthrough varicella had a significantly lower incidence of fever (P < .001) and a significantly shorter duration of illness (P < .001). Other associated constitutional complaints and complications were not significantly different between groups.

CONCLUSION

Varicella in vaccine recipients is clinically modified and significantly less severe than natural disease.

Safety and immunogenicity of a combined diphtheria, tetanus, pertussis and Haemophilus influenzae type b vaccine in young infants

OBJECTIVE

To study the safety and immunogenicity of a combined diphtheria-tetanus-pertussis (DTP)-Haemophilus influenzae type b (HbOC) vaccine (TETRAMUNE) in infants as young as 2 months of age as compared to separate administration of DTP and HbOC.

METHODS

Two-month-old infants were randomized to receive three doses 2 months apart of either DTP-HbOC as a single 0.5-mL injection or to receive 0.5 mL of DTP and HbOC concurrently in separate legs. Local and systemic adverse reactions were monitored within 72 hours of each immunization, and immunogenicity of each of the four vaccine components was measured.

RESULTS

The incidence of both local and systemic adverse events following the tetravalent vaccine was similar to the incidence following separate vaccine administration. After three doses of vaccine, the response to each of the vaccine components was higher in the combined vaccine when compared to separate administration. In the case of the Haemophilus influenzae type b component, this enhancement was also seen after two doses. The response to the combined vaccine was consistent among the three lots tested as was the enhancement over separate administration.

CONCLUSIONS

The DTP-HbOC vaccine was safe and immunogenic in young infants and was generally more immunogenic than separate vaccination with DTP and HbOC. The use of such a combined vaccine reduces the number of injections given to young infants by half and is an important step toward improving vaccine delivery.

Immunogenicity of Haemophilus influenzae type b polysaccharide-tetanus toxoid conjugate vaccine in infants

OBJECTIVE

To compare the safety and immunogenicity of three investigational lots of Haemophilus influenzae type b polysaccharide-tetanus toxoid (PRP-T) conjugate vaccine in infants.

DESIGN

A multicenter, randomized immunogenicity trial. Infants were vaccinated at 2, 4, and 6 months of age with one of three lots of PRP-T. A control group received H influenzae type b oligomers conjugated to CRM197 (HbOC). Serum was obtained before each injection and 1 month after the third dose, and assayed blindly for antibody in one laboratory.

SUBJECTS

Four hundred eighty-four infants from private pediatric practices located in five geographic areas.

MEASUREMENTS AND RESULTS

There were no significant differences in the number of adverse events reported for infants receiving PRP-T or HbOC, and the rates did not exceed those observed previously in infants given diphtheria-tetanus-pertussis vaccine alone. Total serum anti-PRP antibody responses were analyzed in 336 infants who met strict inclusion criteria. After one, two, or three doses, the respective antibody responses to each of the three lots of PRP-T and to HbOC vaccine were similar. The only exception was one lot of PRP-T, which after one or two injections elicited significantly higher geometric mean antibody responses than the other two lots or the HbOC vaccine. After a third injection, there were no significant lot differences. Combining the data from the different lots, there were no significant differences in the geometric mean antibody concentration after three doses of PRP-T or HbOC (8.3 vs 7.7 micrograms/mL), and 95% and 91%, respectively, of infants had greater than 1.0 microgram/mL of antibody. There were no significant differences in the magnitudes of the respective IgG1-, IgG2-, and IgM-specific antibody concentrations between infants given PRP-T or HbOC.

CONCLUSIONS

The three investigational lots of PRP-T tested were safe and were as immunogenic as or more so than the licensed HbOC conjugate vaccine.

Simultaneous administration of a diphtheria and tetanus toxoids and acellular pertussis vaccine with measles-mumps-rubella and oral poliovirus vaccines

OBJECTIVE

To compare the safety and immunogenicity of Lederle Laboratories' (Pearl River, NY) diphtheria and tetanus toxoids and acellular pertussis (DTaP) vaccine with diphtheria and tetanus toxoids and whole-cell pertussis (DTwP) vaccine when administered simultaneously with measles-mumps-rubella (MMR) vaccine and trivalent oral poliovirus (OPV) vaccine at 15 to 16 months of age.

DESIGN

Randomized and double-blind.

SETTING

Two general pediatric practices.

PARTICIPANTS

Ninety-seven infants, aged 15 to 16 months, who had received three previous DTwP immunizations. SELECTION PROCEDURES AND INTERVENTIONS: Healthy children received the DTaP or DTwP vaccine. Infants received the MMR vaccine at a separate site and the OPV vaccine concurrently. Blood was obtained on day 0 and at 6 weeks. Adverse events were recorded by parents at specified times after immunization.

MEASUREMENTS/RESULTS

Within 3 days of immunization, DTaP vaccine recipients had less fever, drowsiness, and irritability (P = .01, .04, .01, respectively). They also experienced less tenderness, erythema, and induration (.001, .001, and .002, respectively). There was no difference in the frequency of adverse reactions 6 to 14 days after immunization. Enzyme-linked immunosorbent assays were used to determine all antibody values. Antibody responses to filamentous hemagglutinin and pertussis toxoid were significantly greater in the DTaP group (P = .0001 and .02, respectively). Immune responses to the other measured antigens were similar.

CONCLUSIONS

Simultaneous administration of the Lederle DTaP with MMR and OPV vaccines did not interfere with antibody response to pertussis antigens measured or measles, mumps, or rubella viruses and was associated with fewer local and systemic adverse events during the first 3 days following immunization when compared with the simultaneous administration of the DTwP, OPV, and MMR vaccines. We conclude that the DTaP vaccine can be administered at 15 months of age concurrently with the MMR and OPV vaccines.

Clinical reactions and immunogenicity of the BIKEN acellular diphtheria and tetanus toxoids and pertussis vaccine in 4- through 6-year-old US children

OBJECTIVE--To compare the immunogenicity and reactogenicity of a two-component acellular pertussis vaccine with a whole-cell diphtheria and tetanus toxoids and pertussis vaccine (W-DTP) when administered as a booster to children 4 through 6 years of age. DESIGN--This was a randomized, double-blind study. SETTING--Children in this study were from three general pediatric practices (two were private, one was university-affiliated). PARTICIPANTS--Three hundred and sixteen 4- through 6-year-old children who had received four previous W-DTP immunizations at the recommended times were studied. SELECTION PROCEDURES AND INTERVENTIONS--Children were randomly assigned in a 1:3 ratio to receive either W-DTP or one of three lots of acellular diphtheria and tetanus toxoids and pertussis vaccine (A-DTP). The A-DTPs contained 3.75 micrograms each of lymphocytosis promoting factor and filamentous hemagglutinin protein nitrogen per 0.5 mL and the same concentrations of diphtheria and tetanus toxoids as W-DTP. Serum samples were obtained on the day of immunization and 4 to 6 weeks later. Adverse reactions were recorded by parents at 6, 24, 48, and 72 hours. MEASUREMENTS AND RESULTS--An indirect enzyme-linked immunosorbent assay (ELISA) method determined IgG antibody response to lymphocytosis promoting factor, filamentous hemagglutinin, and tetanus toxoid; a CHO cell assay measured neutralizing antibodies to pertussis toxin; and serum neutralization on VERO cells assayed diphtheria antitoxin. One month after booster doses were administered, the geometric mean antibody levels for A-DTP vs W-DTP were IgG filamentous hemagglutinin, 362 vs 104 ELISA U/mL; IgG lymphocytosis promoting factor, 408 vs 81 ELISA U/mL; CHO cell, 210 vs 107; diphtheria, 21.7 vs 12.1 U/mL; and tetanus, 2.86 vs 2.04 Eq/mL. Following immunization with A-DTP, local and systemic adverse experiences were 30% to 50% and 20% to 30% fewer, respectively, as compared with W-DTP. CONCLUSIONS--The BIKEN A-DTP vaccine used in this study demonstrates enhanced immunogenicity to lymphocytosis promoting factor, filamentous hemagglutinin, and other measured antigens and less reactogenicity compared with licensed W-DTP [corrected].

Response of 7- to 15-month-old infants to sequential immunization with Haemophilus influenzae type b-CRM197 conjugate and polysaccharide vaccines

OBJECTIVE

To evaluate the immunologic potential of infants 7 to 15 months of age to respond to Haemophilus influenzae type b polysaccharide vaccine following immunization with H influenzae b oligosaccharide-CRM197 conjugate vaccine.

STUDY DESIGN

One hundred seventy-one infants, aged 7 to 15 months, were consecutively and alternatively assigned to one of three immunization protocols. Group 1 (n = 71) received three doses of H influenzae b oligosaccharide-CRM197 conjugate vaccine, group 2 (n = 47) received two doses of H influenzae b oligosaccharide-CRM197 conjugate vaccine followed by one dose of H influenzae type b polysaccharide vaccine, and group 3 received one dose of H influenzae b oligosaccharide-CRM197 conjugate vaccine followed by two doses of H influenzae type b polysaccharide vaccine. Immunizations were given on day 0 and at 2 months and 6 months. Anti-H influenzae type b polysaccharide antibody levels were measured on day 0 and 2, 3, 6, 7, and 12 months after the study began.

RESULTS

Haemophilus influenzae type b polysaccharide vaccine given as a second dose stimulated an antibody rise but did so less effectively than H influenzae b oligosaccharide-CRM197 conjugate vaccine. Two doses of H influenzae b oligosaccharide-CRM197 conjugate vaccine were highly immunogenic; geometric means were 31 and 35 micrograms/mL in the 7- to 11-month and 12- to 15-month age groups, respectively. Following two doses of H influenzae b oligosaccharide-CRM197 conjugate vaccine, both immunization protocols resulted in (1) equally high geometric mean antibody levels 1 month after immunization and (2) similar geometric mean antibody levels 6 months after immunization.

CONCLUSIONS

Haemophilus influenzae b oligosaccharide-CRM197 conjugate vaccine induces antibody levels that would be expected to protect infants from initial invasion and primes the immune system for an anamnestic response. Our data indicate that if a booster immunization is needed, H influenzae type b polysaccharide vaccine could be an alternative to H influenzae b oligosaccharide-CRM197 conjugate vaccine.

Comparison of antigenuria after immunization with three Haemophilus influenzae type b conjugate vaccines

The incidence of antigenuria was documented after vaccination of 75 children 15 to 60 months of age with one of three Haemophilus influenzae type b conjugate vaccines, PRP-D (ProHIBiT), PRP-T and HbOC (HibTITER). Unconcentrated and concentrated urine was tested on the first, third, fifth and seventh days after vaccination. Antigenuria occurred on Day 1 in 100% of PRP-D, 43% of PRP-T and 12% of HbOC recipients. The percentages of children excreting antigen on Day 3 were 95, 17 and 8%; on Day 5 they were 36, 4 and 12%; and on Day 7 they were 14, 0 and 18% for PRP-D, PRP-T and HbOC, respectively. The difference in the occurrence of antigenuria resulting from each vaccine was statistically significant on Day 1 and for PRP-D compared with PRP-T or HbOC on Day 3. It is important for clinicians to be aware of the frequency with which antigenuria occurs after these vaccines so that appropriate therapeutic decisions can be made.

Use of atracurium besylate to arrest fetal activity during intrauterine intravascular transfusions

Prevention of movement during intrauterine transfusion is important to facilitate the procedure and to prevent injury to the fetus. We administered atracurium besylate to the fetus via the umbilical vein during 12 intrauterine intravascular transfusions. A dose of 0.2-0.4 mg/kg of estimated fetal weight was administered after needle entry into the umbilical vein. With a dose of 0.2 mg/kg, fetal movement was slowed transiently. Thereafter, 0.4 mg/kg was administered. All recipients were paralyzed for the duration of the procedure. Fetal activity returned 20-130 minutes later.

Intravascular monitoring and management of erythroblastosis fetalis

Over a 27-month period 17 pregnancies in 16 patients with severe red blood cell isoimmunization were managed with intravascular transfusions performed in utero. Fourteen of these women were Rh negative and sensitized to D or to both D and C, and the remaining two patients were sensitized to the Kell antigen (K). In 12 of the 17 cases (71%) the first intravascular transfusion was performed at 26.5 weeks' gestation or earlier. Thirty-nine of 45 attempted transfusions (87%) were successfully performed. All were done percutaneously under ultrasonic guidance. Two procedures were partial exchanges, while the remainder were straight transfusions. Thirteen of the 17 fetuses (76%) were alive at birth and survived the neonatal period. Four fetuses died in utero at 25 to 26 weeks' gestation, all within 12 hours of an intravascular transfusion. When the 27 procedures attempted during the most recent 9 months of this series were compared with the 18 procedures attempted during the preceding 18 months, no appreciable differences in technical success or fetal outcome were evident. An analysis of this experience is presented, along with modifications in technique that have been implemented. Unresolved issues are discussed.

Limited diagnostic value of routine cord blood bilirubin determinations

In a retrospective study, cord blood bilirubin levels of 87 neonates who received standard phototherapy for neonatal hyperbilirubinemia were compared with the cord bilirubin levels of 95 neonates without neonatal hyperbilirubinemia, none of whom received phototherapy. There were no significant differences in the cord bilirubin levels between the two groups. These results suggest that routine determination of cord blood bilirubin levels is neither necessary nor cost effective.