Double Jeopardy: Prematurity and Congenital Heart Disease-What's Known and Why It's Important

This article is based on a composite of talks presented during the Double Jeopardy: Prematurity and Congenital Heart Disease Plenary Session at NeoHeart 2020, a global virtual conference.Prematurity and low weight remain significant risk factors for mortality after neonatal cardiac surgery despite a steady increase in survival. Newer and lower weight thresholds for operability are constantly generated as surgeons gather proficiency, technical mastery, and experience in performing complex procedures on extremely small infants. The relationship between birth weight and survival after cardiac surgery is nonlinear with 2 kilograms (kg) being an inflection point below which marked decline in survival occurs.The prevalence of congenital heart disease (CHD) in premature infants is more than twice that in term born infants. Increased risk of preterm birth in infants with CHD is most commonly due to spontaneous preterm birth and remains poorly understood.Advances in Neonatal-Perinatal medicine have led to a marked improvement in survival of neonates born prematurely over the last several decades. However, the risk of severe morbidities including retinopathy of prematurity, intraventricular hemorrhage, bronchopulmonary dysplasia and necrotizing enterocolitis remains significant in extremely low birth weight infants. Premature infants with CHD are at a greater risk of prematurity related morbidities than premature infants without CHD. Interventions that have been successful in decreasing the risk of these morbidities are addressed.

Enteral feeding during indomethacin and ibuprofen treatment of a patent ductus arteriosus

OBJECTIVE

To test the hypothesis that infants who are just being introduced to enteral feedings will advance to full enteral nutrition at a faster rate if they receive "trophic" (15 mL/kg/d) enteral feedings while receiving indomethacin or ibuprofen treatment for patent ductus arteriosus.

STUDY DESIGN

Infants were eligible for the study if they were 23(1/7)-30(6/7) weeks' gestation, weighed 401-1250 g at birth, received maximum enteral volumes ≤60 mL/kg/d, and were about to be treated with indomethacin or ibuprofen. A standardized "feeding advance regimen" and guidelines for managing feeding intolerance were followed at each site (N = 13).

RESULTS

Infants (N = 177, 26.3 ± 1.9 weeks' mean ± SD gestation) were randomized at 6.5 ± 3.9 days to receive "trophic" feeds ("feeding" group, n = 81: indomethacin 80%, ibuprofen 20%) or no feeds ("fasting [nil per os]" group, n = 96: indomethacin 75%, ibuprofen 25%) during the drug administration period. Maximum daily enteral volumes before study entry were 14 ± 15 mL/kg/d. After drug treatment, infants randomized to the "feeding" arm required fewer days to reach the study's feeding volume end point (120 mL/kg/d). Although the enteral feeding end point was reached at an earlier postnatal age, the age at which central venous lines were removed did not differ between the 2 groups. There were no differences between the 2 groups in the incidence of infection, necrotizing enterocolitis, spontaneous intestinal perforation, or other neonatal morbidities.

CONCLUSION

Infants required less time to reach the feeding volume end point if they were given "trophic" enteral feedings when they received indomethacin or ibuprofen treatments.

Systemic hyperthermia induces ischemic brain injury in neonatal mice with ligated carotid artery and jugular vein

Postnatal d 7 (p7) or p12 mice had their right carotid artery (CA) and jugular vein (JV) ligated to mimic veno-arterial (VA) access for extracorporeal membrane oxygenation (ECMO). At p9-11 (early) or p19-21 (late) mice were exposed to hyperthermia or normothermia followed by assessment of neuropathological injury score. In separate cohorts of mice, cerebral and peripheral blood flow (CBF, PBF) and cerebral ATP content was measured. Hyperthermia resulted in ischemic brain injury in 57% and 77% of mice subjected to early or late hyperthermia, respectively. Isolated CA+JV ligation induced minimal injury (score 0.47 +/- 0.34) in 2/8 mice from the late normothermia group. No cerebral injury was detected in mice subjected to early normothermia. In 3/19 shams (2/10 early, 1/9 late) hyperthermia induced a subtle (score, 0.6 +/- 0.27) injury in the ipsilateral to the site of surgery cortex. CBF and PBF increased in response to hyperthermia in all mice. The rise in CBF was significantly attenuated in the "ligated" versus intact hemisphere, which was associated with a profound depletion of ATP content. Systemic hyperthermia induces ischemic brain injury in mice with ligated CA+JV. We speculate that hyperthermia/fever can be a potential risk factor for brain injury in infants treated with VA ECMO.

Burr-hole versus twist-drill drainage for the evacuation of chronic subdural haematoma: a comparison of clinical results

BACKGROUND

Most neurosurgeons remove clinically symptomatic subdural haematomata, but the techniques they choose remain controversial.

METHOD

The results from sixty-two patients diagnosed with chronic subdural haematoma were evaluated for technique, postoperative computerized tomography (CT) scan results, and complications.

RESULTS

Eleven patients had haematomata evacuated using twist-drill plus drain, 37 patients had haematomata evacuated with burr-hole only, and 14 patients were evacuated with burr-hole plus drain. Of the patients who underwent twist-drill and closed system drainage (CSD), 43% had smaller lesions on CT follow-up scans, as compared with 74% of those who underwent the burr-hole only procedure, and 65% with burr-holes with drains. Clinical outcome results showed that 64% of twist-drill and CSD patients deteriorated as compared with 16% of those with burr-hole only and 7% with burr-holes and CSDs. Sixty-four per cent of twist-drill patients required repeat evacuations as compared with 11% of those with burr-holes only, and 7% with burr-holes plus drains.

CONCLUSION

The results at our institution indicate that burr-hole evacuation for chronic subdural haematoma is superior to twist-drill evacuation with respect to clinical outcomes and complications.

Cauda equina compression by malignant lymphoma: long-term survival following multimodality therapy

Malignant lymphoma compression of the cauda equina is rare. In the literature only a few cases have been described with occasional long term survivors. We report another case of non-Hodgkin's lymphoma presenting with cauda equina compression. Significant palliation and long-term survival were achieved after therapy by decompressive, cytoreductive surgery; local irradiation; and chemotherapy.

Monoclonal antibodies against ICAM-1 and CD18 attenuate cerebral vasospasm after experimental subarachnoid hemorrhage in rabbits

BACKGROUND AND PURPOSE

Inflammatory responses have been implicated in the elaboration of several forms of central nervous system injury, including cerebral vasospasm after subarachnoid hemorrhage (SAH). A critical event participating in such responses is the recruitment of circulating leukocytes into the inflammatory site. Two of the key adhesion molecules responsible for the attachment of leukocytes to endothelial cells are intercellular adhesion molecule-1 (ICAM-1) and the common beta chain of the integrin superfamily (CD18). This study examined the effects of monoclonal antibodies on ICAM-1 and the effects of CD18 on cerebral vasospasm after SAH.

METHODS

A rabbit model of SAH was utilized to test the influence of intracisternally administered antibodies to ICAM-1 and CD18 on cerebral vasospasm. Antibodies were administered alone or in combination, and the cross-sectional area of basilar arteries was assessed histologically on day 2 post-SAH.

RESULTS

Treatment with antibodies to ICAM-1 or CD18 inhibited vasospasm by 22% and 27%, respectively. When administered together, the attenuation of vasospasm increased to 56%. All of these effects achieved statistical significance.

CONCLUSIONS

These findings provide the first evidence that the severity of cerebral vasospasm can be attenuated using monoclonal antibodies against ICAM-1 and CD18. The results reinforce the concept that cell-mediated inflammation plays an important role in cerebral vasospasm after SAH and suggest that therapeutic targeting of cellular adhesion molecules can be of benefit in treating cerebral vasospasm.

Early diagnosis and treatment of neonatal sepsis

Perinatally acquired bacterial neonatal sepsis is a low incidence, high risk disease with a relatively benign treatment. Accurate diagnosis is difficult because there is no definitive diagnostic test; even blood cultures have an unacceptably low sensitivity. Therefore, the clinician must accept that a number of neonates who do not have the disease will have treatment initiated for sepsis. In order to treat rapidly all infants with sepsis and to minimize therapy for those without infection, historical, clinical, and laboratory data can be used together in a management approach to achieve optimal results. A systemized approach using history, examination, sepsis screen laboratory tests, and cultures is presented to guide clinical management.

Nosocomial infections in neonates receiving extracorporeal membrane oxygenation

OBJECTIVE

To determine the incidence of, and risk factors for, nosocomial infections in neonates during and after treatment with extracorporeal membrane oxygenation (ECMO).

DESIGN

A retrospective cohort study of all infants treated with ECMO during a 4-year period.

PATIENTS

26 neonates experiencing 32 nosocomial infections, and 54 neonates with no nosocomial infections.

SETTING

A large, urban children's hospital.

RESULTS

30% of neonates treated with ECMO experienced at least one nosocomial infection. The rate of nosocomial infections was 10.3 per 1,000 patient-days. Risk factors significantly associated with nosocomial infection included duration of ECMO > 7 days (mean, 12 vs 7 days; odds ratio [OR], 2.84; 95% confidence interval [CI95], 0.96-8.56); neonatal intensive care-unit stay > 21 days (mean, 44 vs 19 days; OR, 8.73; CI95, 2.49-31.94); hospitalization > 50 days (mean, 63 vs 29 days; OR, 5.44; CI95, 1.47-20.87); and surgical procedure before or during ECMO (46% vs 22%; OR, 4.58 CI95, 1.25 to 17.38).

CONCLUSIONS

Nosocomial infections occurred in 30% of patients undergoing ECMO. Although nosocomial infections were not associated with an increase in mortality, hospitalization was prolonged.

Albumin synthesis in premature infants: determination of turnover with [15N]glycine

Albumin turnover was studied in seven small premature infants who received a constant infusion of [15N]glycine for 60-72 h. Gas chromatography-mass spectrometry was used to measure the rate of appearance of [15N]glycine in albumin isolated from the blood. By comparing the linear increment of [15N]glycine in blood albumin with plateau labelling of urinary [15N]hippurate, which was assumed to reflect intrahepatic isotopic abundance in [15N]glycine, the fractional synthetic rate for albumin was found to be 0.09-0.177 day-1 (mean +/- SD = 0.122 +/- 0.041 day-1). The absolute synthesis rate for albumin was 0.3 +/- 0.099 g/dl plasma X day-1 and the total plasma synthetic rate was 117.6 +/- 37.0 mg/kg X day-1. The glycine flux was 326.0-927.7 mumol/kg X h-1 (mean +/- SD 516.7 +/- 218.4 mumol/kg hr-1). The percentage of the glycine flux incorporated into albumin in the total vasculature was 0.425 +/- 0.344. The fractional synthetic rate and the absolute synthetic rate for albumin in these small premature infants are much higher than values obtained in healthy young adults studied with a similar methodology. The relatively low serum albumin concentrations typical of premature infants appear to be referable to more rapid turnover of a small plasma pool rather than a diminution in the rate of albumin synthesis.

Response of preterm infants to diphtheria-tetanus-pertussis immunizations

To establish guidelines for the routine use of diphtheria, tetanus, and pertussis (DTP) vaccine in preterm infants, we quantitated antibody responses of preterm infants to DTP and determined the nature and extent of side effects. Twenty-five preterm infants were immunized with 0.5 ml DTP vaccine at routine intervals. Term infants served as controls. Immediately before each immunization and 2 months after the third, DTP-specific antibodies were quantitated. Clinical side effects were determined by parental report. After the second immunization, 100% of preterm infants had evidence of specific antibody production against diphtheria, tetanus, and pertussis. The incidence of side effects was low, but irritability was significantly more common in preterm infants after the second immunization. These observations suggest that the initiation of primary immunization with DTP in preterm infants need not be delayed beyond 2 months of age.

Potentiation of neuromuscular weakness in infant botulism by aminoglycosides

A retrospective study of ten patients with infant botulism who received gentamicin or kanamycin suggests that aminoglycoside antibiotics potentiate muscular weakness and precipitate respiratory failure as late as 27 days after onset of the disease. Although it is difficult to separate progression of the disease from the effects of antibiotics, the rapidity of deterioration following aminoglycoside treatment and the rapidity of recovery following cessation of aminoglycoside therapy is highly suggestive. A review of five patients who received only penicillin or a semisynthetic derivative of penicillin did not reveal any temporal deterioration with onset of penicillin therapy or improvement with cessation of penicillin therapy.