Safety of primary nasotracheal intubation in the pediatric intensive care unit (PICU)

Background

Nasal tracheal intubation (TI) represents a minority of all TI in the pediatric intensive care unit (PICU). The risks and benefits of nasal TI are not well quantified. As such, safety and descriptive data regarding this practice are warranted.

Methods

We evaluated the association between TI route and safety outcomes in a prospectively collected quality improvement database (National Emergency Airway Registry for Children: NEAR4KIDS) from 2013 to 2020. The primary outcome was severe desaturation (SpO2 > 20% from baseline) and/or severe adverse TI-associated events (TIAEs), using NEAR4KIDS definitions. To balance patient, provider, and practice covariates, we utilized propensity score (PS) matching to compare the outcomes of nasal vs. oral TI.

Results

A total of 22,741 TIs [nasal 870 (3.8%), oral 21,871 (96.2%)] were reported from 60 PICUs. Infants were represented in higher proportion in the nasal TI than the oral TI (75.9%, vs 46.2%), as well as children with cardiac conditions (46.9% vs. 14.4%), both p < 0.001. Severe desaturation or severe TIAE occurred in 23.7% of nasal and 22.5% of oral TI (non-adjusted p = 0.408). With PS matching, the prevalence of severe desaturation and or severe adverse TIAEs was 23.6% of nasal vs. 19.8% of oral TI (absolute difference 3.8%, 95% confidence interval (CI): - 0.07, 7.7%), p = 0.055. First attempt success rate was 72.1% of nasal TI versus 69.2% of oral TI, p = 0.072. With PS matching, the success rate was not different between two groups (nasal 72.2% vs. oral 71.5%, p = 0.759).

Conclusion

In this large international prospective cohort study, the risk of severe peri-intubation complications was not significantly higher. Nasal TI is used in a minority of TI in PICUs, with substantial differences in patient, provider, and practice compared to oral TI.A prospective multicenter trial may be warranted to address the potential selection bias and to confirm the safety of nasal TI.

MRSA infections in children

MRSA infections continue to be a serious and formidable challenge to health care providers and their prevalence is increasing exponentially. In the past, MRSA infections were observed only in hospitalized patients whereas now they are encountered in the outpatient setting. Understanding the pattern of the widespread distribution of MRSA as well as the factors associated with its spread are paramount to its recognition and eradication. The current state of MRSA transmission, control and management is reviewed.

The diagnostic gap in diarrhoeal aetiology

It is well established that rotaviruses of group A are the most important cause of severe diarrhoea in children. The causes of most cases of infectious diarrhoea still remain unidentified, however, and there must be other viruses to be found. 'Novel' rotaviruses have recently been discovered, mainly in animals (serogroups B and C in pigs and humans, D in birds, and one or more further groups in sheep and other mammals). Except for the group B virus which has caused widespread outbreaks of quite severe diarrhoea in adults in China (still not reported from outside China) these novel rotaviruses are rarities in the human and probably represent uncommon zoonotic infections. We speculate that the Chinese virus might have arisen by reassortment of genetic segments of animal group B viruses or perhaps by mutation, and so became infectious for man. The problem of identifying and determining the importance of small round viruses is reviewed. It seems likely that the group of small, round structured viruses, including Norwalk and the viruses of plainly calicivirus morphology, are all representatives of a whole group of enteric caliciviruses. Until they can be more easily cultivated it will be difficult to make diagnostic reagents available to all. Astroviruses and genuine parvoviruses have been found by many people in many countries. Astroviruses are probably more important as pathogens in lambs than in children or calves; parvoviruses can only be established as significant in epidemics. The coronavirus-like particles, first found in Vellore and Bristol, are still enigmatic and their role in diarrhoea is uncertain. Toroviridae, recently discovered as causes of diarrhoea in ungulates, do not seem to be at all important as causes of diarrhoea in humans. Possibly fruitful approaches to future searches are outlined: firstly to make more extensive use of immuno-electron microscopy; and secondly to try to improve existing tissue culture systems to make them more sensitive to enteric viruses.

Work of breathing associated with pressure support ventilation in two different ventilators

The purpose of this study was to compare the work of breathing during pressure support ventilation (PSV) with positive end expiratory pressure (PEEP) utilizing the Siemens SV300 (SV300) and Dräger Evita 4 (EV4) ventilators. Our hypothesis was that patients' work of breathing (WOB(P)) would be unchanged in PSV utilizing flow triggering (FT) in both the SV300 and EV4. We compared two ventilators using six healthy, intubated, sedated, spontaneously breathing pigs weighing approximately 10 kg each. WOB(P) (j/L) and ventilator work of breathing (WOB(V)) (j/L) were measured using a portable monitor which utilizes an esophageal balloon and flow transducer. Each breath was further analyzed for duration of inspiratory effort and negative deflection of pressure needed to trigger PSV. Animals were studied with the SV300 and EV4 on a pressure support of 5 cmH(2)O and PEEP settings of 0 and 5 cmH(2)O. Data were analyzed using the Wilcoxon signed rank test with significance set at P <or= 0.05 WOB(P) was 90% (PS 5, PEEP 0) and 52% (PS 5, PEEP 5) lower on the SV300 compared to the EV4. WOB(V) was 94% (PS 5, PEEP 0) and 39% (PS 5, PEEP 5) higher on the SV300 when compared to the EV4. The change in airway pressure (delta p) from baseline and most negative deflection of pressure were greater with the EV4 as compared to the SV300, although delta pressure was not found to be statistically significant on PS of 5 cmH(2)O and PEEP of 5 cmH(2)O. The SV300 also had shorter duration of inspiratory effort from initiation of breath to most negative deflection of pressure and to maximum flow than the EV4. In conclusion, these results suggest there are significant differences in WOB(P) between the SV300 and EV4 ventilators. Response time of the ventilators may explain the differences in duration of inspiratory effort and the patient's work of breathing and thus may have an impact on weaning time for ventilated patients.

An evaluation of Automode, a computer-controlled ventilator mode, with the Siemens Servo 300A ventilator, using a porcine model

BACKGROUND

Weaning of mechanical ventilation in patients optimally includes meeting their needs by making frequent ventilator adjustments. The Siemens Servo 300A mechanical ventilator is designed to allow the ventilator to be interactive with the patient's needs by making breath-by-breath adjustments in both control and support modes. We undertook the following experiment to validate that the Automode algorithm responded appropriately using a pediatric animal model when apnea occurred and if there was any impact on work of breathing.

METHODS

We ventilated 6 sedated spontaneously-breathing piglets using Automode in pressure-regulated volume control/volume support (PRVC/VS) mode, pressure control/pressure support (PC/PS) mode, and volume control/volume support (VC/VS) mode. Data were collected using both a computerized respiratory monitor and data acquisition system that recorded and analyzed individual animal breaths for response time, effort of triggering, and work of breathing. Data collection began with the animals breathing spontaneously in each support mode, followed by the administration of a short-acting neuromuscular blocker (succinylcholine) to induce apnea, thus allowing the ventilator to switch between modes automatically. Data collection was continued before, during, and after apnea to observe the duration of inspiratory effort, trigger response time, and any significant pressure or flow variances of the Automode feature. In addition, patient work of breathing (WOB(P)) and ventilator work of breathing (WOB(V)) were measured before and after each phase.

RESULTS

We found no instances of failure of Automode to follow the predetermined algorithms. There was a difference in both the amount of change in pressure and most negative deflection of pressure by each animal during triggering in the post-paralysis phase (p < 0.05). Response time for individual breaths was shorter from initiation of breath to most negative deflection of pressure during the post-paralysis phase (p < 0.05). Maximum flow reached was lower in the post-paralysis phase for VC/VS and PC/PS (p < 0.05). We also found WOB(P) decreased and WOB(V) increased in the post-paralysis phase for all modes tested.

CONCLUSIONS

The Automode algorithm performed as expected in this animal experiment. We conclude that differences in response time and negative deflection of pressure, as an indication of animal effort, and maximum flow reached were due to continued weakness from the neuro-muscular blocker. However, the ventilator continued to trigger despite decreased effort by the animal.

Comparison of work of breathing between two neonatal ventilators utilizing a neonatal pig model

OBJECTIVE

The purpose of this study was to determine whether variations in the delivery systems of continuous positive airway pressure between two ventilators would lead to differences in patient work of breathing (WOBp).

DESIGN

Comparison of two neonatal ventilators with a neonatal pig model.

SETTING

Animal laboratory.

SUBJECTS

Thirty healthy, intubated, sedated, spontaneously breathing neonatal piglets weighing 1.0-2.0 kg.

INTERVENTIONS

Patient work of breathing (WOBp) (gm cm/kg) was measured by using measurements based on an esophageal balloon and a flow transducer. Each breath was analyzed for ventilator response times (in msecs) and negative deflection of pressure. Each animal was studied with the Siemens SV300 and Drager Babylog 8000, on continuous positive airway pressure settings of 0, 3, and 5 cm H2O. Data were analyzed by using Wilcoxon's Signed Rank Test with significance of p <or=.05.

MEASUREMENTS AND MAIN RESULTS

Comparing ventilators, WOBp was on average 29% higher in the Babylog. Analysis of individual breaths showed that disparity in WOBp was probably related to the automatic availability of 2 cm H2O pressure support ventilation in the SV300. This may also explain the differences in delay time during the start of the inspiratory phase before initiation of gas flow. The mean duration of inspiratory effort was 394 (+/- 157) msecs in the Babylog and 138 (+/- 35) msecs in the SV300, a 174% increase in time delay for the Babylog (p =.005). During inspiratory effort, there was >1 cm H2O negative pressure before flow was available with the Babylog.

CONCLUSIONS

In intubated patients, maximum energy expenditure occurs at the initiation of ventilator breaths. WOBp in neonatal pigs was significantly increased. The response time of the ventilators may explain the differences in initiation of flow times and patient work. These differences may have important implications for energy kinetics, weight gain, and duration of mechanical ventilation in preterm neonates.

Bacterial, viral and parasitic aetiology of paediatric diarrhoea in the highlands of Papua New Guinea

Enteropathogens and clinical features associated with diarrhoea were investigated in 1526 children admitted over a 5-year period to the paediatric ward of a hospital in the highlands of Papua New Guinea. Overall, a recognized pathogen was isolated from 39 per cent of the children admitted with diarrhoea. The most commonly isolated agents were rotavirus (23 per cent), Shigella spp. (13 per cent), Campylobacter spp. (12 per cent), Cryptosporidium parvum (10 per cent) and enteropathogenic Escherichia coli (8 per cent). The clearest clinical associations were rotavirus with vomiting, and Shigella with blood and pus in the stool. A control series of children admitted with other complaints was also included, and the odds ratios for diarrhoea for the above five pathogens were 18.2, 9.6, 3.7, 2.2, and 1.6, respectively.

Bacterial and viral etiology of severe infection in children less than three months old in the highlands of Papua New Guinea

OBJECTIVE

Determine the bacterial and viral etiology of severe infection in young Papua New Guinean infants as part of a multicenter study in four developing countries aimed at improving case management guidelines.

METHODS

Between March, 1991, and April, 1993, children aged <3 months were recruited at the outpatient department of Goroka Base Hospital, Papua New Guinea (PNG). Children with pre-defined inclusion criteria were enrolled, a history was taken and clinical examination was performed. Blood and urine were collected from children with signs suggestive of severe disease together with eye, umbilical and pernasal swabs as appropriate. Nasopharyngeal aspirates (NPAs) were collected from children with and without signs of severe disease for identification of viruses and Chlamydia trachomatis by direct fluorescent antibody staining.

RESULTS

3280 infants were triaged and 2168 enrolled, among whom 968 had signs suggestive of severe disease. Group A Streptococcus (Streptococcus pyogenes) and Staphylococcus aureus were the most important bacterial pathogens isolated from children < 1 month old with severe infections, and Streptococcus pneumoniae, S. pyogenes and Staphylococcus aureus were most important in older children. Of 292 eye swabs 19 (7%) grew Neisseria gonorrhoeae. Of 116 umbilical swabs 51 (44%) grew S. pyogenes and 45 (39%) grew Staphylococcus aureus. Respiratory syncytial virus was the most important viral cause of acute lower respiratory infection.

CONCLUSIONS

S. pyogenes, S. pneumoniae and Staphylococcus aureus are important causes of severe infection in young children in the PNG highlands. It is necessary to improve access to clean water, promote hand-washing in the hospital and at home and investigate further the use of maternal immunization for the prevention of severe disease in young infants.

High rates of Chlamydia trachomatis infections in young Papua New Guinean infants

OBJECTIVE

Determine the importance of Chlamydia trachomatis in the etiology of severe infection in young Papua New Guinean infants.

METHODS

Between March, 1991, and April, 1993, children <3 months old were recruited as outpatients at Goroka Base Hospital, Papua New Guinea, as part of a multicenter study in four developing countries. Children with predefined inclusion criteria were enrolled. C. trachomatis was identified by direct fluorescent antibody staining in nasopharyngeal aspirates (NPAs) collected from children with and without signs of severe disease and eye swabs from children with and without conjunctivitis. Two to three radiologists read chest radiographs without knowledge of clinical and laboratory findings.

RESULTS

Of 3280 outpatients seen 2168 enrolled, 955 NPAs were tested for C. trachomatis and 549 chest radiographs were read. Of 210 eye swabs from children with conjunctivitis 57% were positive for C. trachomatis compared with 8% from 167 children with no conjunctivitis. The prevalence of C. trachomatis in NPAs was 9% in asymptomatic children and 18 and 33% in children with nonsevere or severe pneumonia, respectively. C. trachomatis in NPAs was strongly associated with clinically severe pneumonia [odds ratio (OR), 2.91], reduced arterial oxygen saturation (OR 2.58) and radiographic evidence of pneumonia (OR 5.84) and was also associated with pneumococcal bacteremia (OR 3.48).

CONCLUSIONS

In Papua New Guinea Chlamydia must be considered as a cause when treating pneumonia in infants, and effective treatment and prevention of sexually transmitted diseases are urgently needed for a number of reasons, including the need to curb high rates of chlamydial infection in women and infants.

OEIS complex (omphalocele-exstrophy-imperforate anus-spinal defects) in monozygotic twins

The omphalocele-exstrophy-imperforate anus-spinal defects (OEIS) complex is a consistent and recognizable pattern of midline abdominal and pelvic defects. It is rare, affecting 1 in 200,000 to 400,000 pregnancies and is even rarer in twin gestations. This is an autopsy study of OEIS complex in monozygotic twins after pregnancy termination at 20 weeks of gestation. Unremarkable family history but concordance of monozygotic twins for the defects may support the theory that early malformation complexes, e.g., OEIS, and monozygotic twinning are manifestations of the same disturbance of early blastogenesis.

Legal problems related to obstetrical ultrasound

Malpractice suits related to fetal anomalies are now the most common type of litigation involving ultrasound, surpassing ectopic pregnancy. Missing an anomaly on a sonogram performed for a standard indication, such as dating, is the most frequent type of litigation. Other causes of litigation include invented anomalies and unrecognized anomalies that are visible in retrospect on the ultrasonic images. Rarer causes of malpractice problems relate to failure to communicate the results of a sonogram in a timely fashion, failure to inform the patient of the findings about the sonogram at the time the patient is seen, and failure to perform ultrasound studies for anomalies when there is clinical indication to do so, such as elevated alpha-fetoprotein or polyhydramnios. The level of protection given by the obstetrical guidelines are discussed. Particular areas of concern relate to litigation involving missed fetal heart malformations, spina bifida, absent distal limbs, and twins.

Health impact assessments of malaria and Ross River virus infection in the Southern Highlands Province of Papua New Guinea

Malaria at an elevation of 1050 metres is common and highly endemic in the Tagari Valley in the Southern Highlands of Papua New Guinea. Health impact assessments showed that the risks of malaria and epidemic polyarthritis at a gasfield development project in this area were high. Baseline malariometric surveys were conducted in four villages in June and August 1990 and two follow-up surveys (May and December 1991) were made in the village of Nogolitogo near the gasfield pioneer base camp. A total of 941 blood smears were examined. Average malaria prevalence rates decreased with altitude from 56% (at 1050 m) to 9% (at 1700 m) for children 1-9 years of age and from 45% (at 1050 m) to 8% (at 1550 m) for those aged 10 years or more. The spleen rate for children less than 10 years old did not vary significantly with altitude, but average enlarged spleen for all ages decreased with altitude. Mean packed cell volume increased with altitude. Plasmodium falciparum was the most common malaria parasite found and Anopheles punctulatus the predominant vector. Ross River arbovirus (RRV) antibody prevalence was 59%. These results indicate frequent or constant transmission of malaria and pathogenic arboviruses. Entomological and epidemiological data suggested that the vulnerability of the valley community, the receptivity of the environment and the health hazards from malaria and RRV were high. Nonimmune Papua New Guineans and expatriate employees face high health hazards; therefore effective preventive measures are required to mitigate epidemics and avoid the likely heightened transmission of malaria and arboviruses caused by the development project.

Criteria for the prenatal diagnosis of classic bladder exstrophy

OBJECTIVE

To define ultrasonographic criteria for the prenatal diagnosis of classic bladder exstrophy.

METHODS

Forty-three prenatal ultrasound scans were studied from 25 pregnancies in which live delivery of an infant with classic bladder exstrophy occurred. The diagnosis of bladder exstrophy could be made retrospectively in 29 prenatal studies from 17 pregnancies. The time of the fetal ultrasound varied from 14-36 weeks' gestation (mean 23). The diagnosis of bladder exstrophy was made before delivery in only three cases.

RESULTS

Five factors associated with bladder exstrophy were identified: 1) The bladder was not visualized on ultrasound in 12 of 17 cases (71%); 2) a lower abdominal bulge representing the exstrophied bladder was seen in eight of 17 cases (47%); 3) a small penis with anteriorly displaced scrotum was identified in eight of 14 males (57%); 4) the umbilical insertion was low set in five of 17 cases (29%); and 5) abnormal widening of the iliac crests was seen in three of 17 cases (18%).

CONCLUSION

The prenatal diagnosis of bladder exstrophy should be considered any time the bladder is not visualized or any of the aforementioned factors are noted.

Osteogenesis imperfecta and campomelic dysplasia: difficulties in prenatal diagnosis

The classic features of osteogenesis imperfecta and campomelic dysplasia typically are so specific that these two forms of skeletal dysplasia are among the few that can be diagnosed in the second trimester of pregnancy. We report a series of seven examples of osteogenesis imperfecta and one example of campomelic dwarfism to illustrate the difficulty of differentiating these two disorders in utero. The prenatal sonographic findings in three of the osteogenesis imperfecta cases mimicked campomelic dwarfism, whereas the case of campomelic dwarfism was antenatally diagnosed as osteogenesis imperfecta.

Arbovirus disease in Papua New Guinea

It is clear that exposure to arthropod-borne viruses is common in the populations of both Papua New Guinea and Irian Jaya. Clinical disease resulting from these infections has been reported although the paucity of case reports and combined clinical experience suggest that it is rare. Dengue epidemics due to dengue-1 and dengue-2 have occurred and it is likely that dengue-3 is also present in the region. No cases of dengue haemorrhagic fever have been described. Murray Valley encephalitis, Ross River and antigenically related viruses are widespread in Papua New Guinea and Irian Jaya, particularly in the lowland and coastal areas. Antibodies to Japanese encephalitis virus have not been found in blood samples from Papua New Guinea or Irian Jaya. As Papua New Guinea is developed, new areas of the country are opened up and ecosystems are altered. It is important that physicians based in Papua New Guinea, and those who deal with patients living or working here, are aware of the arbovirus diseases which occur and the potential and preventable problems posed by them to both the individual and the community.

Immunoglobulin G antibody responses to polyvalent pneumococcal vaccine in children in the highlands of Papua New Guinea

The immunoglobulin G (IgG) antibody responses to a pneumococcal polysaccharide vaccine were examined for 480 children aged 3 months to 5 years and living in Tari, Southern Highlands Province, Papua New Guinea. Antipneumococcal IgG to the seven serotypes most frequently causing invasive disease (types 2, 5, 6B, 7F, 14, 19F, and 23F) was measured by an enzyme-linked immunosorbent assay in serum collected before vaccination and 1 and 6 months after vaccination. Prevaccination antibody levels fell rapidly after 3 months of age and remained low throughout the first 2 years of life. One month after vaccination, geometric mean titers of antipneumococcal IgG to serotypes 2, 7F, 23F, and 5 were at least twice those of antibodies in nonvaccinated children of the same age from the ages of 5, 6, 9, and 12 months onwards, respectively; postvaccination antibody responses to serotypes 6B, 14, and 19F rose gradually during the second year of life. Elevated antibody titers to serotypes 2 and 7F were maintained 6 months after vaccination. Thus, young Papua New Guinean children are capable of mounting a good immune response to some pneumococcal capsular polysaccharides from a young age, and the antibody responses to capsular polysaccharides are consistent with studies in developed countries. However, in Papua New Guinea, the serogroup distribution of invasive disease matches the immunogenic components of the pneumococcal polysaccharide vaccine more closely than in developed countries, a fact which helps to explain the results of controlled trials in Papua New Guinea, in which this vaccine prevented death and severe morbidity from pneumonia in young children.

The role of ultrasound in prostate cancer detection in patients with an elevated prostate specific antigen level but no prostatic nodule

An increased level of prostate specific antigen (PSA) in the blood is a relatively sensitive indicator of prostate disease; a significant minority of men with increased PSA will have prostate carcinoma. A total of 736 men with a PSA elevation of greater than 4.2 without a rectally palpable prostate mass were evaluated with transrectal ultrasound at the Ultrasound Institute of Baltimore over a three-year period. Transrectal biopsy under ultrasound control was performed when a localized mass was seen on ultrasound or the prostate was small and the PSA level significantly elevated (93% of the series underwent biopsy). There was a positive biopsy yield for cancer of 38.5% in the cases biopsied. This high positive yield was achieved by combining high quality ultrasound with two to three samples from a visible mass and random samples from other sites.

The prevalence of antibodies to human T-lymphotropic virus type I in different population groups in Papua New Guinea

Isolation and partial sequencing of human T-lymphotropic virus type I (HTLV-I) variants from inhabitants of Papua New Guinea (PNG) and the Solomon Islands has confirmed the existence of virus infection in Melanesian populations. To determine the geographical distribution of seropositivity to HTLV-I in PNG we have tested 2907 serum and plasma samples collected between 1972 to 1991 from 16 different population groups. Samples were screened using a particle agglutination assay and confirmed by p21e-enhanced Western immunoblot (WB). From a total of 94 screen positive samples run on WB, 56 (60%) were confirmed positive (positive for both env and gag products) and 38 (40%) were WB-indeterminate (gag products only). The prevalence of WB-confirmed antibodies to HTLV-I in lowland and island populations ranged from 0 to 5.4%. There were no confirmed antibody positives in the highland populations surveyed. Geographically isolated populations living on the fringes of the highlands ranged in seropositivity from 0.2 to 5.8%. Two of the subjects surveyed gave WB antibody patterns characteristic of HTLV-II rather than HTLV-I infection.

Ultrasonic clues to the detection of chromosomal anomalies

The ultrasonic detection of fetal anomalies may well be the most challenging aspect of diagnostic ultrasound and, because ultrasonic clues to a chromosomal anomaly may be subtle, much depends on high quality ultrasound. Although difficult, the field is exciting and rewarding. It is hoped that recognition of the various common manifestations of chromosomal anomalies described in this article will increase the number of chromosomal anomalies detected and ameliorate the consequences of these disorders.

Levels of anti-pneumococcal antibodies in young children in Papua New Guinea

Anti-pneumococcal polysaccharide antibody (anti-PPS) levels were measured in 153 serum samples collected from children aged between 2 and 47 months living in the highlands of Papua New Guinea (PNG). Fifty-seven of the samples were collected during acute episodes of lower respiratory tract infection (ALRI). Total IgA and IgG increased steadily with age; however, no association was found between the levels of these antibodies and the health status of the child. Total IgM levels showed little relationship to the age of the child but under 12 months of age levels were somewhat higher on average in children with pneumonia. For most of eight pneumococcal serotypes tested, specific IgG levels were found to decline rapidly in the first 6-8 months, reaching a minimum at approximately 12 months of age. Serotype 3 was exceptional in having very low titres in the youngest children. A separate analysis of 24 cord sera suggested that antibodies to this serotype do not usually cross the placenta in PNG. Children with pneumonia tended to have lower levels of specific IgG than healthy controls of the same age. Specific anti-PPS IgA levels were found to increase steadily with age, but were not associated with health status.

Increased echogenicity in the fetal abdomen: use of DNA analysis to establish a diagnosis of cystic fibrosis

The sonographic finding of increased echogenicity within the fetal abdomen presents a diagnostic dilemma, with a differential diagnosis ranging from normal variation to CF. We report the diagnostic evaluation of four cases, two of which were found to be the result of CF. On the basis of this experience, we believe that persistence of an echogenic bowel pattern, especially with bowel dilation, after 20 weeks' gestation should prompt an evaluation for CF. Using DNA analysis, approximately 75% of the cases involving CF can be detected with noninvasive studies of the parents, and confirmation by amniocentesis is performed only in those cases in which both parents are carriers of known mutations.

The carriage of Streptococcus suis type 2 by pigs in Papua New Guinea

An indirect fluorescent antibody test was used to detect the presence of Streptococcus suis type 2 in nasal and pharyngeal swabs taken from pigs in Papua New Guinea. The rate of carriage for the two sites in domesticated indigenous village pigs was 0.5 and 2.5% respectively, compared to 39 and 43% for intensively reared pigs. These findings were supported by the results of a serological survey, using an enzyme linked immunosorbent assay, in which 87% of intensively reared pigs but only 8% of village pigs were seropositive to S. suis type 2. It is proposed that in intensive piggeries S. suis type 2 is continually cycled between pigs. In village pigs, the low population density and harsh environmental conditions prevents this cycle of infection.

In utero sonography of genitourinary anomalies

Congenital anomalies of the genitourinary system represent the commonest fetal anomaly. The sonographic findings in hydronephrosis, multicystic kidney (dysplastic kidney), polycystic kidney, and renal agenesis are reviewed.

Markers of hepatitis B infection in Tari District, Southern Highlands Province, Papua New Guinea

Serum samples collected from two groups in the Tari District of Southern Highlands Province were assayed for markers of hepatitis B virus (HBV) infection. 85% of women of childbearing age were found to have markers of HBV infection; 37% were positive for HBV surface antigen (HBsAg), indicative of the chronic carrier state, and 6.6% were positive for HBV e antigen (HBeAg), indicating the presence of actively replicating virus. 75% of women negative for HBsAg were positive for antibody to HBV core antigen (HBcAb), a marker of past infection. A group of children aged 6 to 18 years showed a significantly lower prevalence of markers of infection (66%) but higher rates of HBsAg positivity (46%) and HBeAg positivity (30%). Only 37% of the HBsAg-negative children in this group were positive for HBcAb. The results from this serosurvey suggest that the major route of HBV transmission in this population is horizontal, between older children, though significant transmission also occurs during the neonatal period.

Failure to isolate human T cell lymphotropic virus type I and to detect variant-specific genomic sequences by polymerase chain reaction in Melanesians with indeterminate western immunoblot

The controversy over the endemicity of human T cell lymphotropic virus type I (HTLV-I) in Melanesia has been settled recently by the isolation of genetically distinct, highly divergent sequence variants of HTLV-I from unrelated inhabitants of Papua New Guinea and the Solomon Islands. Still at issue, however, is the significance of the high frequency of indeterminate HTLV-I Western blots (defined as reactivity to only gag-encoded proteins) among Melanesians. To investigate whether this indeterminate seroreactivity reflects specific reactivity to the Melanesian HTLV-I variants, 27 seroindeterminate Melanesians from Papua New Guinea and the Solomon Islands were studied for evidence of HTLV-I infection. Although antibodies against Melanesian variant-specific env gene products and variant-specific env gene sequences were detected by Western blot analysis and polymerase chain reaction, respectively, in all 11 HTLV-I Western blot-positive Melanesians, none of the 27 seroindeterminate Melanesians had such variant-specific antibodies or HTLV-I proviral sequences. In addition, attempts to isolate HTLV-I from seroindeterminate individuals were unsuccessful. These data indicate that HTLV-I infection is not the cause of the indeterminate Western blot reactivity seen in Melanesia.

Subacute sclerosing panencephalitis (SSPE) in Papua New Guinea: a high incidence in young children

Eighty-seven cases of subacute sclerosing panencephalitis (SSPE) were diagnosed from September 1988 to April 1991 in Papua New Guinea (PNG), by demonstration of high-titre measles-specific antibodies in cerebrospinal fluid (CSF). For 1990 the annual incidence of SSPE, for the study provinces, was calculated to be 56 cases per million under 20 years of age and it is expected that this figure will be higher in 1991. The mean age of presentation was 4.9 years, with a male to female ratio of 1.8:1. An elevation in the ratio of immunoglobulin G as a percentage of total protein in CSF and an increase in the CSF:serum immunoglobulin G ratio was shown in SSPE patients. The dramatic appearance and high frequency of the disease in PNG might relate to the early age of measles infection encountered in children in this country.

Obstructed uterovaginal anomalies: demonstration with sonography. Part II. Teenagers

The sonograms of 13 patients with obstructed uterovaginal anomalies were reviewed to determine the role of sonography in diagnosis and management. In a retrospective analysis, the authors were able to define the cause of the obstruction and the upper level and length of the obstruction by combining the sonographic findings with those from the physical examination (ie, bulging hymen, blind vaginal pouch, no vaginal depth, normal vagina) or by combining transabdominal sonography with simultaneous digital insertion into the vaginal orifice. When the sonogram demonstrated hematometrocolpos or hematocolpos, the lesion was due to an imperforate hymen (n = 1) or high, middle, or low transverse vaginal septum (n = 7). When the sonogram demonstrated a hematometra, the lesion was due to Mayer-Rokitansky-Küster-Hauser syndrome with functioning uterine anlage(n) (n = 2), cervical dysgenesis (n = 1), and an obstructed uterine horn (n = 2). The presence and patency or absence of the cervix was established. Since the differentiation between a transverse vaginal septum, Mayer-Rokitansky-Küster-Hauser syndrome with active anlagen, and cervical dysgenesis with absent vagina cannot be made clinically, sonography provides important presurgical information.

Prenatal diagnosis of structural abnormalities

In the past year, improved ultrasonographic quality has allowed the imaging of more and more subtle anomalies. A major focus of recent discussion, ie, whether the combination of ultrasonographic and maternal blood test results (eg, serum alpha-fetoprotein level) is a satisfactory screening method for commonplace anomalies such as Down's syndrome or spina bifida, is reviewed. Whether these noninvasive tests need to be supplemented by amniocentesis is also discussed, as are ultrasonographic markers for various trisomy syndromes and the association between renal abnormalities and chromosomal defects.

Immunogenicity of standard dose Edmonston-Zagreb measles vaccine in highland Papua New Guinean children from four months of age

A small-scale trial was carried out at Tari in the Southern Highlands Province of Papua New Guinea to determine the effectiveness of a standard subcutaneous dose of Edmonston-Zagreb measles vaccine (Institute of Immunology, Zagreb) administered to children at less than 8 months of age. Specific antibody levels were measured before and 7-11 weeks after vaccination using an ELISA system. Paired sera from 41 children vaccinated at 4-7 months of age and from 18 children vaccinated routinely at 8-29 months of age were available for comparison. No child 6 months of age or older had detectable maternal antibodies and all of these seroconverted. Post-vaccination titres in 12 children aged 6-7 months were not significantly different from those in older children and 1 year later, post-vaccination titres were still high. In Papua New Guinea, and perhaps in other developing countries, it may prove appropriate and acceptable to vaccinate with Edmonston-Zagreb measles vaccine at 6 months of age without recourse to augmentation of dose from that currently recommended in older children.

Obstructed uterovaginal anomalies: demonstration with sonography. Part I. Neonates and infants

The sonograms of five neonates with an obstructed urogenital sinus and four with an obstructed cloaca were retrospectively reviewed to determine the sonographic features and the role of pre- and postnatal sonography in the diagnosis and management of hydrocolpos. On pre- and/or postnatal sonograms, the obstructed genital tract was visualized in seven neonates as a large cystic pelvic-abdominal mass, which was the markedly distended urine-filled vagina. One neonate had multiple cystic masses, which resulted from an obstructed duplex genital tract. In one of the neonates with an obstructed cloaca, the anomaly was not diagnosed. The bladder was compressed by the distended vagina and was not visualized in five patients. A vaginal fluid-debris level in six patients was a key finding that distinguished the vagina from the bladder. Obstruction of the urinary tract was an associated feature. An obstructed uterovaginal anomaly with renal dysplasia and oligohydramnios on prenatal sonograms indicates a poor prognosis. Sonography contributes to the diagnosis of an obstructed genital tract and helps define the internal genital anatomy.

Rotavirus excretion by village pigs in Papua New Guinea

Cohort studies were conducted on 29 pigs from 3 villages in the Highlands of Papua New Guinea. Animals ranged in age from 9 d to 5 m old. Three hundred and twenty nine faecal samples were collected from individual pigs followed over 3 to 6 w periods, and were examined for group A rotavirus antigen by ELISA, and rotaviral genomic RNA by polyacrylamide gel electrophoresis (PAGE). Electron microscopy was also conducted on selected samples. Group A rotavirus was detected in the faeces of 16 pigs with infected individuals coming from all villages. Non-group A rotavirus resembling group C was found in faeces from pigs from 2 villages. All of the group A rotaviruses examined had the same electrophoretype and this was distinct from that of the common type infecting humans in the area at the time of the study. None of the group A positive samples reacted with monoclonal antisera specific for human group A rotaviruses of serotypes 1, 2, 3, 4, or 8. The non-group A rotaviruses also all had identical electrophoretypes. In contrast to previous findings in intensive piggeries, rotavirus infection did not occur in all young pigs and was not limited to young animals under 2 m of age. Infected pigs varied in age from 12 days to 20 weeks of age. This pattern of infection was attributed to the non-intensive husbandry situations in the villages, with less opportunity for transmission to occur than in intensive piggeries.

Pelvic masses: aspiration biopsy with transrectal US guidance

Biplanar, transrectal ultrasound guidance was used in the transrectal aspiration of two pelvic abscesses, one recurrent tumor, and one sterile, nonmalignant fluid collection. This method provides an alternative path that allows precise localization for aspiration biopsy of pelvic masses.

Solitary nonparasitic hepatic cyst causing abdominal distension and respiratory distress in a newborn

This is a report of a girl infant born with a protuberant abdomen and respiratory distress. A cystic mass was excised from the liver.

HTLV-I antibody studies in villagers in East Sepik Province, Papua New Guinea

Serum samples collected in 1984 during a malariometric survey of two villages in the East Sepik Province of Papua New Guinea were tested for antibodies to HTLV-I. None of the villagers showed any symptoms suggestive of retrovirus infection. Eighteen of the 186 (9.5%) sera tested at that time were found to be positive. Blood samples were subsequently obtained from fifteen of the eighteen positives and subjected to analysis by enzyme-linked immunosorbent assay (ELISA), radioimmuno assay (RIA), radioimmunoprecipitation assay (RIPA), and Western blot (WB). Fourteen of the fifteen gave a positive ELISA response, but none were unequivocally positive by p 24 RIA. All sera tested were reactive to gag antigens by WB, but gave "indeterminate" results currently accepted criteria. Notably absent from the WB profiles of all of the study subjects was an antibody response to HTLV-I envelope protein gp 46. It is possible that these antibody responses are directed against a variant of HTLV-I or to a novel retrovirus which possesses core antigens similar to those of HTLV-I but has different envelope antigens. Until a virus is isolated, or the viral genome is identified in infected lymphocytes, the possibility remains that the response may be due to factors unrelated to retrovirus infection.

Fetal genitourinary tract anomalies: evaluation, operative correction, and follow-up

The prenatal diagnosis of a genitourinary anomaly was made in 53 fetuses. Sonographic findings, antenatal course, and postnatal treatment and outcomes were examined. No interventional therapy was undertaken in utero, and the natural history could be examined in the 44 of 53 (83%) who did not electively terminate their pregnancies. Twenty-three of the total 53 (43%) had unilateral disease and 30 (57%) had bilateral involvement. Thirty-five of 53 (66%) survived, with 22 undergoing operative therapy postnatally. In all but one of the 35 survivors, the anomaly was isolated to the genitourinary tract, and the majority of surviving fetuses had unilateral disease. Oligohydramnios was present in only three of 35 survivors, and none had severe oligohydramnios. Nine of 53 women underwent termination of pregnancy and nine others experienced a neonatal death. All 18 of their fetuses had bilateral disease, with oligohydramnios present in 14 (78%). All five fetuses with chromosomal abnormalities were found in this group of 18. The majority of fetuses with a genitourinary anomaly will do well postnatally. Pulmonary hypoplasia, extrarenal anomalies, and chromosomal defects are frequent findings in the minority with poor outcomes. A multidisciplinary approach to management of the pregnancy with a fetal genitourinary tract anomaly is essential to optimize outcome.

Prenatal ultrasonic detection of anomalies with a lethal or disastrous outcome

Although rare, a number of fetal anomalies can be detected with ultrasound in which the prognosis is either fetal death or minimal development. Anomalies of this type include anencephaly, holoprosencephaly, hydranencephaly, iniencephaly, cystic hygroma with hydrops, cystadenomatoid malformation of the lung with hydrops, conjoined twins of some types, renal agenesis, bilateral renal dysplasia, lethal dwarfing syndromes, and some forms of hydrops. Syndromes in which the severe form only are fatal include intracranial teratoma, encephalocele, pentalogy of Cantrell, vein of Galen aneurysm, the limb body wall complex, and infantile polycystic kidney. Sonographic findings of these conditions and other rarer lethal lesions are reviewed.

Cholecystokinin prevents parenteral nutrition induced biliary sludge in humans

Long term total parenteral nutrition (TPN) induces biliary sludge and formation of gallstones. Cholecystectomy is hazardous in these patients because of the underlying medical problems. Therefore, a randomized, double-blind controlled study was designed to test the hypothesis that daily administration of cholecystokinin-octapeptide (CCK-OP) prevents the formation of biliary sludge in humans receiving long term TPN. Adult patients receiving TPN for more than 21 consecutive days were studied. After randomization of 15 patients, the study was concluded because statistical significance was achieved. Eight patients received saline solution (placebo) intravenously and seven received CCK-OP (50 nanograms per kilogram) intravenously over a ten minute period daily. The groups were similar with respect to age, sex, diagnosis, liver function tests, amylase levels, total TPN time and time of study. All of the patients underwent weekly ultrasound studies. Volume and emptying studies of the gallbladder in response to the study drug were performed after one week. None of the patients receiving CCK-OP had sludge whereas five of eight of the patients receiving placebo had sludge (p less than 0.02). The results of emptying studies showed significant contraction of the gallbladder in those in the CCK-OP group but not in the placebo group. These data suggest that CCK-OP given intravenously daily prevents TPN induced stasis and sludge of the gallbladder. We conclude that CCK-OP should be used as routine prophylaxis against biliary sludge and formation of gallstones in patients receiving long term TPN.

Relationship between image quality and ultrasound exposure level in diagnostic US devices

Ultrasonographic B-mode images were obtained at various exposure levels with three real-time diagnostic scanners. Adult human and tissue-equivalent phantom images were compared in terms of diagnostic content and depth of penetration. For the exposure level settings used, spatial-peak pulse-average intensities ranged from approximately 10 to 500 W/cm2. At the 3.50-3.75-MHz nominal frequencies used in the study, images of the human abdomen showed little discernible change in quality with varying exposure levels. However, phantom tests confirmed that depth of penetration is a function of exposure level. The results suggest that a judicious use of exposure level and receiver gain controls can be a practical means for minimizing patient exposure to ultrasound without sacrifice of diagnostic effectiveness.

Evaluation of transrectal ultrasound in the early detection of prostate cancer

To determine the ability of transrectal ultrasound to detect early localized prostate cancer, unsuspected (nonpalpable) cancer in the contralateral lobe of patients undergoing radical prostatectomy for clinically localized disease was evaluated. A total of 59 patients with palpable prostate cancer clinically confined to 1 lobe underwent transrectal ultrasound before radical prostatectomy and step-sectioning of the radical prostatectomy specimen. Transrectal ultrasound was performed with 5 or 7 MHz. real-time transrectal units. Pathological findings in these 59 cases revealed no tumor in the contralateral lobe in 34 (58%) and the presence of unsuspected tumor in 25 (42%). Transrectal ultrasound detected 13 of 25 unsuspected cancers for a sensitivity of 52%. Of 34 patients with no contralateral lobe lesion transrectal ultrasound was correct in 23 for a specificity of 68%. The positive and negative predictive values for transrectal ultrasound in this study group were 54 and 66%, respectively. There was no significant difference in the pathological size of the clinically suspected and clinically unsuspected cancers as measured by average largest dimension, and transrectal ultrasound sensitivity did not correlate with the size of the cancer. Based on careful sonopathological analysis, transrectal ultrasound may not be a good method to detect clinically unsuspected prostate cancer and the false positive rate would appear to be high.

Sonographic observations in a patient with typhlitis

The sonographic findings in a patient with typhlitis are presented. Sonography showed a solid mass with a "target" sign in the right lower quadrant, continuous with the ascending colon. In addition to suggesting the diagnosis, sonography was helpful in the follow-up examination of the patient because it was able to assess the gradual decrease in the thickness of the bowel wall and ultimate resolution of the inflammatory process.

Temporal relationship between A1 adenosine receptor upregulation and alterations in bicuculline seizure susceptibility in rats

The temporal requirements for theophylline-induced upregulation of A1 adenosine receptors and elevation of seizure threshold were examined. Chronic theophylline exposure (75 mg/kg twice daily) elicited a significant upregulation of [3H]cyclohexyladenosine ([3H]CHA) binding sites following 7 and 14 days of treatment. Alterations in seizure threshold followed a similar temporal pattern of development. The reversibility of theophylline-induced upregulation of high affinity [3H]CHA binding sites was complete at 10 days following cessation of theophylline administration, while the alteration of seizure threshold required 21 days to return to control values.

Lethal fetal anomalies: sonographic demonstration

Sonographic demonstration of a lethal fetal anomaly may dramatically alter obstetrical management. For example, cesarean section for fetal distress may not be performed if it is known that the fetus will not survive outside the uterus. The author describes the common fetal anomalies that are predictably fatal.

Determination of canine prostatic size in situ: comparison of direct caliper measurement with radiologic and transrectal ultrasonographic measurements

The use of transrectal ultrasonography to estimate canine prostatic size in situ was evaluated and compared to that of direct measurement via calipers and an in situ radiologic procedure. The length, width, and depth of prostates were measured by transrectal ultrasound in both the transverse and sagittal planes from which prostatic volume was calculated. Prostatic volumes were subsequently transformed into prostatic weights using the following nomogram: prostatic Weight (g) = 0.602 x prostatic Volume (cm3) + 1.16. Prostatic weights estimated by ultrasound as well as by direct measurement with caliper were similar (P greater than 0.10) to the true gravimetric weight; however, prostate weights estimated by the radiological X-ray procedure were significantly (P less than 0.01) lower. The relationship between true gravimetric prostate weight and that estimated by ultrasound was described by the following regression equation: estimated weight (g) = 1.127 gravimetric weight (g) - 1.665; r = 0.900; P less than 0.001; n = 23. In summary, the results of this study demonstrate that transrectal ultrasonography can be used to accurately predict canine prostatic weight.

Comparison of transvaginal and transabdominal sonography in the detection of early pregnancy and its complications

Ninety women with a positive pregnancy test and signs and symptoms of threatened abortion or ectopic pregnancy had endovaginal and abdominal sonography in order to compare the value of the two techniques for the detection of gestational abnormalities. Either a normal delivery occurred or surgical and/or pathologic confirmation of the diagnosis was available in all cases. Fifty-five women had normal intrauterine pregnancies, 22 had ectopic pregnancies, seven had blighted ova, and six had missed abortions. All 55 normal intrauterine pregnancies were detected by endovaginal sonography, while only 11 (20%) were diagnosed by transabdominal sonography. The yolk sac, fetal pole, and fetal heart motion were seen as early as 34 days from the last menstrual period with endovaginal sonography, compared with 42 days with transabdominal sonography. Fetal heart motion was detected with endovaginal sonography in fetal poles with a crown-rump length of 3 mm or greater, whereas the fetal pole had to be at least 6 mm before fetal heart motion could be detected with the transabdominal technique. In the 22 ectopic pregnancies, a specific diagnosis of an extrauterine sac containing a fetal pole with heart motion or yolk sac was possible in three cases with the endovaginal technique, but it was not possible in any case with transabdominal sonography. Both techniques showed that each of the seven patients with final diagnosis of blighted ova had a gestational sac that was 1.7 cm or larger without visualization of the fetal pole or yolk sac. All six missed abortions were detected by endovaginal sonography, but only three were diagnosed on transabdominal sonograms. Our findings show that endovaginal sonography is more sensitive than transabdominal sonography in the detection of early pregnancy and its complications.

Update on prostatic ultrasound

Although there is good evidence that carcinomas of the prostate are usually seen as echopenic masses within the external zone of the prostate, it is unclear how often an echopenic mass has an origin other than carcinoma of the prostate. Technical problems at the periphery of the gland not uncommonly create echopenic areas on an artifactual basis. Whether ultrasound will prove to be a satisfactory screening method for the detection of carcinoma of the prostate is yet to be decided. Prospective studies are in progress, but it has not yet been established whether prostate screening is a worthwhile procedure. The best possible equipment is required to detect these subtle lesions; cheap equipment will probably not give adequate results.

Prenatal diagnosis of sacrococcygeal teratoma: sonographic-pathologic correlation

The prenatal sonograms of 15 fetuses with sacrococcygeal teratoma were reviewed to determine the sonographic appearance and the role of sonography in the obstetric management. Each tumor appeared as a large mass arising from the fetal rump. The teratomas exhibited three sonographic patterns: nine were mixtures of cystic and solid components in equal proportions, four were predominantly solid with a few scattered anechoic areas, and two were unilocular cystic masses. Calcifications were detected in six cases. There was no correlation between the sonographic appearance and the presence of immature or malignant components. Ultrasonography allowed visualization of an intraabdominal component in six cases and assessment of findings that were of prognostic importance. Prenatal detection and size determination of the external component can play an important role in planning obstetric management because fetuses with a large tumor should be delivered by cesarean section to avoid dystocia and catastrophic hemorrhage during delivery.

Neonatal ovarian cysts: sonographic-pathologic correlation

The authors reviewed the prenatal (11 infants) and postnatal (17 infants) sonograms and the clinical, surgical, and pathologic findings in 17 infants with an ovarian cyst to determine the sonographic features and natural history of neonatal ovarian cysts. An uncomplicated cyst (nontwisted, nonhemorrhagic) was completely anechoic and the cyst wall was imperceptible with sonography (five cases). A twisted or hemorrhagic cyst was cystic with a fluid-debris level, cystic with a retracting clot, septated with or without internal echoes, or solid (12 cases). These complicated cysts contained liquid and/or organized hematoma. Eleven of the 12 complicated cysts had a thin, highly echogenic wall. Cyst torsion commonly occurred in utero and could be diagnosed on prenatal sonograms by a typical sonographic appearance (eight cases). All of these infants were asymptomatic after birth. Four infants with hemorrhagic or twisted cysts were symptomatic. All cysts except one that resolved spontaneously were treated surgically, including three twisted cysts that showed no change in size over a 1-8-month interval. All of the cysts were of follicular origin.