An outbreak of Salmonella enteritidis in a maternity and neonatal intensive care unit

We investigated the relationships between methylphenidate (MPD) enantiomers and endogenous dopamine (DA) levels in striatal extracellular fluid, and that between DA level and locomotor activity, after intravenous administration of racemic MPD (2, 5 or 10 mg/kg dose) or the individual enantiomers (2.5 mg/kg dose) to rats. MPD and DA levels in the extracellular fluid were measured by in vivo brain microdialysis. The maximum levels of MPD enantiomers in the striatal extracellular fluid were obtained within 15 min after administration. On the other hand, the mean maximum DA levels after administration of 2-10 mg/kg dose of racemic MPD were obtained within 10 min with values in the range of 3.0- to 8.6-fold higher than the basal DA level. The maximum DA level (4.2-fold of the basal level) after administration of (+/-)-MPD was greater than that (2.2-fold) of the same dose of (-)-MPD. A clockwise hysteresis was observed between MPD concentration and DA level in the extracellular fluid after MPD administration. Locomotor activity after administration of (+)-MPD was also greater than (-)-MPD. From these results, it was shown that the locomotor activity induced by MPD may be related to the increase of DA level in the extracellular fluid, and the degree of increase of the DA level by (+)-MPD was greater than that of the (-)-isomer.     

An outbreak of M serotype 1 group A Streptococcus in a neonatal intensive care unit

OBJECTIVE: To describe the investigation and control of an outbreak of M serotype 1, Streptococcus pyogenes (group A Streptococcus, GAS) infections in a neonatal intensive care unit (NICU). STUDY DESIGN: The study was conducted in an NICU in a large urban university-affiliated hospital. Retrospective review was performed of all infants and health care workers in the NICU, especially those either colonized or infected with GAS during the outbreak and the prospective surveillance period (July through September 1994). Prospective epidemiologic investigation, including cultures of throat, umbilicus, and anorectum (infants), or throat and anus (NICU personnel), identified a possible common source of the disease in case infants. Antimicrobial susceptibility testing and serotyping of all GAS strains were performed; M serotype 1 isolates were examined by DNA analysis with restriction fragment length polymorphism. The M-1 GAS isolates were tested for streptococcal pyrogenic exotoxin (SPE) A and SPE B production. A retrospective chart review and analysis of infants with GAS infection or colonization was conducted. RESULTS: During a 1-week period, two very low birth weight infants more than 3 weeks of age had GAS septicemia and focal infection. Two additional very low birth weight infants with asymptomatic throat colonization were identified during the first week of surveillance. Benzathine penicillin G was administered to all NICU infants, but failed to eradicate throat colonization in the four case subjects. Seven days after completing parenteral antibiotic therapy, the index patient had a recurrence of GAS septicemia that was fatal. Eradication of throat colonization in the remaining three infants was achieved with a 10-day course of intravenous clindamycin therapy. Among 103 NICU personnel, five (4.9%) had asymptomatic GAS colonization with strains that were uniformly susceptible to penicillin. Each colonized adult was successfully treated with oral clindamycin therapy. Serotyping revealed that five isolates of GAS from four infants and one NICU respiratory therapist were M-1 isolates; DNA analysis confirmed that these were the same strain. The five M-1 isolates produced both SPE A and SPE B. CONCLUSIONS: The previously documented increase in prevalence of M-1 strains of GAS in the United States is likely to be associated with their introduction into closed populations including NICUs. Control of such outbreaks may be achieved by isolation, cohorting of case subjects and possible carriers, and successful eradication of colonization in case subjects and carriers. Although GAS organisms are uniformly susceptible to penicillin G, eradication may require agents other than penicillin.     

Outbreak of influenza in a neonatal intensive care unit

An outbreak of influenza A/Victoria/3/75 (H3N2) involving five infants in a neonatal intensive care unit is described. The clinical signs and symptoms were indistinguishable from those seen in bacterial sepsis. There was no evidence of meningoencephalitis. All infants recovered without any sequelae.     

Electrocardiograph monitor artifacts in a neonatal intensive care unit

A wide variety of artifacts may be found when monitoring the ECG in a neonatal intensive care unit. Many of the artifacts resemble arrhythmias, and unless they are recognized as artifacts they may lead to serious errors of diagnosis and therapy. Many of the artifacts are caused by patient movement such as seizures, tremulousness, or hiccups. Others may be introduced by the monitor itself or be caused by electrical equipment in the vicinity. A group of ECG tracings is presented to illustrate the various artifacts encountered. Features that distinguish the artifacts from the arrhythmias they mimic are described, as are suggestions for elimination of the artifacts.     

Candidemia in the neonatal intensive care unit

The hospital records of 18 infants (9 males & 9 females) with one or more positive cultures for Candida species were studied retrospectively in an attempt to define the characteristics, associated factors and treatment for candidemia in the neonatal intensive care unit. The number of patients have increased recently and the mortality rate is 56% (10/18). The Candida species isolated from blood were Candida albicans in 16 cases and Candida parapsilosis in 2 cases. Fever, not-doing-well, and abdominal distention were the most common presentations, prompting us to the initial impression of bacterial sepsis and/or necrotizing enterocolitis. Eleven associated factors for candidemia were relating to the measures and therapy in the neonatal intensive care unit, such as prolonged use of broad-spectrum antibiotics, parenteral hyperalimentation etc. All of these 18 patients were treated with intravenous amphotericin B. Six patients were given adequate total dose (> 25 mg/Kg), while 12 patients underwent inadequate treatment (3.7 +/- 2.9 mg/Kg). The 10 fatal patients belonged to the inadequate treatment group. As there is continual progress in neonatal intensive care units, candidemia is becoming an increasing common problem and which deserves attention.     

Outbreak of systemic aspergillosis in a neonatal intensive care unit

Clinical and manometric results of Delorme's operation and sphincteroplasty were assessed retrospectively in patients undergoing this procedure for fecal incontinence and rectal prolapse. A series of 33 patients (11 males, 22 females; aged 18-83 years, mean 59) with external rectal prolapse were treated by Delorme's operation between 1989 and 1996. Mean follow-up was 39 months (range 7-84). Sphincteroplasty was associated in 12 cases with severe fecal incontinence due to striated muscle defects. Good results were achieved in 27 patients (79%); prolapse recurrence was observed in 6 (21%), the mean recurrence time being 9 months (range 1-24 months). There were no postoperative deaths. Minor complications occurred in 15 patients. Changes in preoperative and postoperative manometric patterns were as follows (mean +/- SEM): voluntary contraction from 59 +/- 6.9 to 66 +/- 7.1 mmHg (P = 0.05), resting tone from 33 +/- 5 to 32 +/- 4.3 mmHg, rectal sensation from 59 +/- 5 to 61 +/- 5.2 ml of air (n.s.). A solitary rectal ulcer syndrome was detected in five patients. The histological pattern demonstrated pathological changes in 40% of cases. Fecal incontinence was resolved in 6 of 20 cases (30%) and chronic constipation in 4 of 9 (44%). Failure (n = 3) was related primarily to postoperative sepsis. The incontinence score showed a mean improvement of 35% decreasing, from 4.5 +/- 0.39 to 2.9 +/- 0.44 after surgery (P < 0.01). In conclusion, Delorme's procedure did not lead to constipation and improved anal continence when associated with sphincteroplasty.     

Experience in a neonatal intensive care unit affects pain response

OBJECTIVE: To determine the effect of being in the neonatal intensive care unit (NICU) on pain responses in infants of 32 weeks' postconceptual age (PCA). DESIGN: A cross-sectional comparative design was used. SETTING: Two level III NICUs, each in metropolitan, university teaching hospitals. PATIENTS: Infants of 32 weeks' PCA born within the past 4 days (the newly born group; n = 53) were compared with infants of the same PCA who had been born 4 weeks earlier (the earlier-born group: n = 36) and had spent that time in an NICU. OUTCOME MEASURES: Heart rate, oxygen saturation levels, and facial actions were used as outcomes in a between-group repeated measures analysis of variance across the heel stick procedure. Background variables of Apgar, weight at birth and data collection, severity of illness, age group, and total number of invasive procedures were entered into a stepwise regression. RESULTS: The two groups responded differently to the heel stick: the earlier-born infants had less behavioral manifestations of pain than the newly born infants. The number of invasive procedures was the primary factor that explained those behavioral differences, with Apgar as a second explanatory factor. The earlier-born infants had higher heart rates and lower oxygen saturation than the newly born infants before as well as during the procedure. These physiological differences were explained by the perinatal factors of age at birth and birth weight. CONCLUSION: Preterm infants who spend PCA weeks 28 through 32 in an NICU are less mature in their pain response than newborn premature infants of 32 weeks' PCA. Greater frequency of invasive procedures is associated with behavioral immaturity, whereas birth factors are associated with physiological immaturity.     

Plastic surgical problems in the neonatal intensive care unit

A Bayesian decision rule for early termination of an experimental study of binary responses is presented. This early termination occurs when the predictive probability of reversing the decision when utilizing the delayed observations is small. The proposed approach utilizes Bayesian inferential tools such as Bayes factors and predictive distributions. A simulation study is conducted to evaluate the performance of the proposed approach. Some guidelines are given to determine when the study should be terminated early and when the investigator should wait for delayed observations before making a conclusion.     

Principles of organization of a neonatal intensive care unit from scratch

The relative amounts of brain-specific antigens, S-100, glial fibrillary acidic protein (GFA), 14.3.2, synaptin C1, D1, D2 and D3 were determined by crossed immunoelectrophoresis in bulk-prepared neuronal, glial and synaptosomal fractions from 35-day-old rat brains. Little enrichment was ontained for any antigen in the neuronal perikaryal fraction. The glial fraction showed a 3.5-fold enrichment in GFA but had levels similar to whole brain with respect to S-100. Synaptosomes were somewhat enriched in the synaptin C1 protein, but did not differ markedly from whole brain with respect to the most antigens. The extent of cross-contamination in the various fractions could be judged only tentatively, partly due to differences in extractability of the proteins.     

Frequency of neurologic disorders in the neonatal intensive care unit

Neonatal intensive care unit survival rates have improved significantly over the past decade. This improvement primarily reflects declining mortality rates among preterm infants. Neurologic morbidity increases with prematurity and is the major predictor of long-term disability. Accordingly, concern has been expressed that the burden of neurologic dysfunction among contemporary neonatal intensive care unit survivors may be increasing. To define the trends of neurologic disorders in the contemporary neonatal intensive care unit, all 4164 admissions between 1986 and 1995 to a tertiary neonatal intensive care unit were examined. Neonatal intensive care unit admissions (413 +/- 49 per year), proportion of births at less than 37 weeks (70 +/- 3% per year), and referral patterns were stable between 1986 and 1995. Over the study period, 773 (18%) of 4164 neonatal intensive care unit infants had a total of 1062 neurologic disorders. The neonatal intensive care unit mortality rate declined from 12% in 1986 to 4.2% in 1995 (P < .01). Neurologic disorders declined, from 27% of infants born in 1986 to 12% in 1995 (P < .001): 356 had seizures (14% in 1986 to 4% in 1995; P < .001), 235 had hypoxic-ischemic encephalopathy (8% in 1986 to 4% in 1995, P < .01), and 167 had intraventricular hemorrhage (7% in 1986 to 1.4% in 1995, P < .005). Frequency of congenital or chromosomal aberration affecting the nervous system was relatively constant (4.5% per year). Despite a three-fold improvement in neonatal intensive care unit survival between 1986 and 1995, the frequency of perinatally acquired neurologic disorders declined by more than 50%.     

Infections caused by Flavobacterium meningosepticum in patients in a neonatal intensive care unit

During a period of three and a half months 7 neonates from a neonatal intensive care unit became infected by F. meningosepticum, serotype B. The pathogens could be isolated from the tracheal secretions and--less frequently--from throat swabs, gastric juice and nose swabs. Environmental sampling led to the isolation of F. meningosepticum from the humidification fluid of the respirator, from vaporizers as well as from the artificial ventilation tubing. F. mengingosepticum was found in the water of humidifiers from 3 children, who developed neither a colonization nor an infection. In a number of cases the patients' environment was contaminated with F. meningosepticum prior to colinization or infection. Nearly identical resistance patterns against the antibiotics tested, could be demonstrated for the isolated strains. The primary source of infection could not be identified, it is supposed however that the index patient had been admitted to the hospital nine months before. A strict hygienic policy, like consequently performed hand hygiene, adequate processing of ventilation equipment and application of sterile tubings led to extinction of the infections. During subsequent environmental controls, F. meningosepticum could not be isolated.     

Fifty-Hertz magnetic field exposures of premature infants in a neonatal intensive care unit

In this study the magnetic flux density in and around incubators of a neonatal intensive care unit was registered and mapped. The mean 50-Hz magnetic flux densities in an incubator were typically in the range of 0.2-1 microT, with maximum values around 1.5 microT. For 1 incubator, harmonics contributed to the field substantially. The field levels varied depending on the type of equipment, the positioning of the electronics and the position of the 240-volt main plugs. The positioning of the infant in the incubator and the precise mattress position in the incubator affected the magnetic flux density to a great extent, as did the positioning of the electronic monitoring and treatment equipment. The flux density values found were fairly low as compared to magnetic field levels present at some work places where high electric currents are used. In intensive care units, however, the duration of exposure can be very long, especially for premature infants. The fields can also be compared with the magnetic field levels of residences and are then approximately 100 times higher. Further studies are necessary -it seems important to record magnetic fields and attempt to reduce the levels. Such a reduction can be achieved by reducing the field from the incubators but also by changing the electronic equipment around the incubators or increasing the distance to the incubator. Further research should of course also study any mechanism by which magnetic fields can affect cells and organisms. Compared to the risks many of these infants are exposed to, it is difficult to say whether the magnetic field levels measured can represent a significant additional risk factor. However, this is an area where one should adopt a prudent avoidance strategy, particulary considering how easily these fields can be reduced, mainly through redesign of the various equipment.     

Reduction of nosocomial infection in a neonatal intensive care unit (NICU)

The aim of this study was to describe an outbreak of hepatitis A in a family group which extended to a day care center and to the families of the children attending the same and to determine the risk of acquiring the disease based on exposure to one or several sources of infection. The temporary distribution of the cases and the rate of hepatitis A in the population at risk were analyzed. The risk of acquiring hepatitis by exposure to one or more sources of infection was studied by logistic regression, calculating the odds ratio and the confidence interval of 95%. Initiation of the outbreak was in May 1996, in a 25-year-old male and finalized in November, having affected 63 people. The rate of global attack was of 12% and the risk of infection 18-fold greater (CI 95% = 5.4-61.8) in those exposed to more than one source of infection than in those exposed to only one source and 3.5-fold greater (CI 95% = 1.2-9.9) in the group from 15 to 29 years of age than in those under 14. The massive administration of immunoglobulin was useful to control the hepatitis in the day care center and in the school. The size of this epidemic of hepatitis A was due to its occurrence in a population little exposed to the virus. The greatest involvement was observed in young adults, with person to person transmission and the greater risk of acquiring hepatitis A on exposure to several sources of infection characterizing the outbreak. The possible usefulness of designing prevention strategies with the vaccine should be considered.     

Septicaemia in an Austrian neonatal intensive care unit: a 7-year analysis

The results of blood cultures and clinical data of 101 neonates with 110 episodes of septicaemia during a 7-y study period were reviewed. The overall incidence of culture-proven sepsis within the study period was 6.0 per 100 neonatal intensive care unit admissions and the mortality rate was 14%. Three groups of pathogens accounted for 70% of all isolates: coagulase-negative staphylococci (27%), aerobic Gram-negative rods (24%) and Enterococcus faecalis (19%). Group B streptococcus was the major pathogen of very early-onset septicaemia (within 24 h of birth), whereas late-onset infections were most commonly caused by coagulase-negative staphylococci. Birthweight <1500 g, gestational age <30 weeks of gestation and early onset of symptoms within the first week of life were associated with poor prognosis. In addition, the case fatality rate of episodes caused by Gram-negative organisms was significantly higher than that of Gram-positive bacteraemia.     

Molecular typing of Klebsiella pneumoniae isolates from a neonatal intensive care unit

The epidemiological features of 60 multiresistant K. pneumoniae strains isolated from 1991 to 1995 in a neonatal ward are described. Antibiotic. Susceptibility testing and plasmid profile analysis were used as subtyping procedures. Antibiotic susceptibility typing was not informative enough since discrimination among isolates was typically poor. Plasmid profile analysis demonstrated that 58 out of 60 strains harboured one or more plasmid DNA bands, of different molecular weights ranging between 1.8 and 150 Mda. Small plasmids were best visualized after the alkaline lysis procedure, while large plasmids by the Kado and Liu method. A combination of plasmid patterns obtained by the two extraction procedures was used to define the final plasmid profile for each strain. Thirteen different plasmid profiles were identified among the collection of K. pneumoniae isolates from newborn patients of the same intensive care unit. The investigation showed that the strains were not responsible for a single outbreak.     

Central venous catheter bloodstream infections in the neonatal intensive care unit

The aim of the study was to investigate the social background of physicians, the reasons that influenced doctors to enter medicine, and the association between those reasons and satisfaction in career choice of young Finnish doctors. An extensive postal questionnaire was mailed to a random sample of 2632 young Finnish doctors in 1988 and to 2332 doctors in 1993. We found out that majority of the respondents reported that interest in people, a wide range of job opportunities, the fact that medicine is a highly-appreciated profession, and success at school had influenced their decision to enter medicine quite a lot or very much. In 1988, 8% and in 1993, 7% of the respondents reported that interest in people had not influenced their career choice at all or only slightly. More women than men were influenced quite a lot or very much by factors like interest in people, success at school and vocation, meaning the lifelong calling to physicians' profession. A total of 22% of respondents would not enter medicine again. Vocation, interest in people and wide range of job opportunities were significantly more rarely mentioned as an important career choice motive by these respondents. It seems that interest in human beings and vocation are important to would-be doctors, and also help them to get along in the physicians' profession. Medical schools should develop their curricula towards more humanistic medicine in order to maintain their students' interest in people.