Inspiratory-expiratory variation of pleural line thickness in neonates with and without acute respiratory failure

BACKGROUND

There are relatively few data about the ultrasound evaluation of pleural line in patients with respiratory failure. We measured the pleural line thickness during different phases of the respiratory cycle in neonates with and without acute respiratory failure as we hypothesized that this can significantly change.

METHODS

Prospective, observational, cohort study performed in an academic tertiary neonatal intensive care unit recruiting neonates with transient tachypnoea of the neonate (TTN), respiratory distress syndrome (RDS) or neonatal acute respiratory distress syndrome (NARDS). Neonates with no lung disease (NLD) were also recruited as controls. Pleural line thickness was measured with high-frequency ultrasound at end-inspiration and end-expiration by two different raters.

RESULTS

Pleural line thickness was slightly but significantly higher at end-expiration (0.53 [0.43-0.63] mm) than at end-inspiration (0.5 [0.4-0.6] mm; p = 0.001) for the whole population. End-inspiratory (NLD: 0.45 [0.38-0.53], TTN: 0.49 [0.43-0.59], RDS: 0.53 [0.41-0.62], NARDS: 0.6 [0.5-0.7] mm) and -expiratory (NLD: 0.47 [0.42-0.56], TTN: 0.48 [0.43-0.61], RDS: 0.53 [0.46-0.65], NARDS: 0.61 [0.54-0.72] mm) thickness were significantly different (overall p = 0.021 for both), between the groups although the absolute differences were small. The inter-rater agreement was optimal (ICC: 0.95 (0.94-0.96)). Coefficient of variation was 2.8% and 2.5% for end-inspiratory and end-expiratory measurements, respectively. These findings provide normative data of pleural line thickness for the most common forms of neonatal acute respiratory failure and are useful to design future studies to investigate possible clinical applications.

Continuous Venovenous Hemofiltration Performed by Neonatologists With Cardio-Renal Pediatric Dialysis Emergency Machine to Treat Fluid Overload During Multiple Organ Dysfunction Syndrome: A Case Series

OBJECTIVES

A new device is available for neonates needing extracorporeal renal replacement therapy. We reviewed the use of this device (in continuous venovenous hemofiltration [CVVH] mode) in term or preterm neonates affected by multiple organ dysfunction syndrome (MODS) with fluid overload.

DESIGN

Case series.

SETTING

Academic specialized referral neonatal ICU (NICU) with expertise on advanced life support and monitoring.

PATIENTS

Neonates with MODS and fluid overload despite conventional treatments and receiving at least one CVVH session.

INTERVENTION

CVVH with the Cardio-Renal Pediatric Dialysis Emergency Machine.

MEASUREMENTS AND MAIN RESULTS

Ten (three preterm) neonates were treated using 18 consecutive CVVH sessions. All patients were in life-threatening conditions and successfully completed the CVVH treatments, which almost always lasted 24 hr/session, without major side effects. Three neonates survived and were successfully discharged from hospital with normal follow-up. CVVH reduced fluid overload (before versus after represented as a weight percentage: 23.5% [12-34%] vs 14.6% [8.2-24.1%]; p = 0.006) and lactate (before versus after: 4.6 [2.9-12.1] vs 2.9 mmol/L [2.3-5.5 mmol/L]; p = 0.001). CVVH also improved the Pa o2 to Fio2 (before vs after: 188 mm Hg [118-253 mm Hg] vs 240 mm Hg [161-309 mm Hg]; p = 0.003) and oxygenation index (before vs after: 5.9 [3.8-14.6] vs 4 [2.9-11]; p = 0.002). The average cost of CVVH in these patients was minor (≈3%) in comparison with the median total cost of NICU care per patient.

CONCLUSIONS

We have provided CVVH to critically ill term and preterm neonates with MODS. CVVH improved fluid overload and oxygenation. The cost of CVVH was minimal compared with the overall cost of neonatal intensive care.

Specific antibody titer decay in neonates prenatally exposed to Toxoplasma gondii and their mothers

BACKGROUND

For infants exposed in utero to Toxoplasma gondii, current guidelines recommend monitoring the specific antibody titer until 12 months of age. In this study, we investigated the antibody titer decay in the mother-infant dyad.

METHODS

This is a single center, population-based cohort study of neonates referred for prenatal exposure to Toxoplasma gondii from January 2014 to December 2020. All infants underwent clinical, laboratory, and instrumental investigation for at least 12 months.

RESULTS

A total of 670 eligible neonates were referred to the Perinatal Infection Unit of the University Federico II of Naples. 636 (95%) completed the serological follow up until 12 months. Specific IgG antibodies negativization occurred in 628 (98.7%) within 5 months. At 9 and 12 months, all patients had negative IgG. An initial neonatal IgG antibody titer ≥ 200 IU/ml was associated with a longer time to negativization (184 [177.5;256] days when above threshold vs. 139.5 [101;179] days when below it; p < 0.001). Maternal IgG antibody titer ≥ 200 IU/ml at childbirth was also associated to delayed time to negativization in the infant (179 [163;184] days above the threshold vs 125 [96.8;178] days below it; p < 0.001). Specific antibody negativization was irreversible in all patients.

CONCLUSIONS

Lower anti-Toxoplasma antibody titers detected at birth in the mother-infant-dyad lead to an earlier and irreversible negativization. This information allows for customisation of the infant follow up program and avoids invasive and expensive tests.

Comparison of body weight, body height and body fatness of Italian children aged 6-12 years with American standards

World Health Organization has suggested that American standards may be adopted for use in countries where no local reference data are available. Since no locally accepted growth standard is available in Italy, this study investigated if American growth curves for weight, height and triceps skinfold (TSF) provide reliable values for Italian children. Weight, height and TSF were measured in 1273 Italian children (boys: 656, girls: 617) ranging in age from 6 to 12 years and their percentiles were compared with that provided by NCHS for American children. Despite some minor differences, it is shown that American standards can be used safely in Italian children aged from 6 to 12 years.

Body impedance measurements during dialysis

Changes in body weight in relation to changes in body impedance were studied in six male and four female patients before and during dialysis. Before dialysis, fat-free mass from skinfolds was 46.5 +/- 6.8 kg, and total body water calculated from bio-electrical impedance was 36.9 +/- 5.2 kg. Body water expressed as a percentage of fat-free mass was calculated to be 80 +/- 4%. Mean weight loss, which was assumed to be only loss of water, was 2.7 +/- 0.7 kg. Total body impedance increased by 80 +/- 16 omega from 495 +/- 39 omega to 575 +/- 47 omega. Weight loss and increase in body impedance were highly correlated (r = -0.91, P less than 0.001). However, based on prediction formulas for total body water from bio-electrical impedance, the observed weight (water) loss should be associated with an increase in impedance of only 39 +/- 11 omega. It is concluded that the impedance value before dialysis is a relatively low value, due to the low specific resistivity of the excess of extra-cellular water in the body before dialysis. As a consequence, prediction formulas for body composition from bio-electrical impedance, developed in normal hydrated subjects, overestimate body composition (total body water, fat-free mass) in subjects with oedema.

Control mechanisms of peripheral enkephalin hydrolysis in mammalian plasma

The protection of the adrenal-released enkephalins from enzyme hydrolysis by endogenous plasma components was studied in laboratory animals and in man. The results indicate that mechanisms active in protecting leu-enkephalin from hydrolysis are present in the plasma of all species examined. The protection seems to be due to two groups of substances, possibly of peptidic nature. The amount of protection given by these substances seems to be sufficient to play a significant role in controlling the physiological levels of leu-enkephalin released into the bloodstream.

Neuronal responses to putative neurotransmitters during penicillin epileptogenesis

An epileptogenic process was induced within the rat frontoparietal cortex by microiontophoretic applications of penicillin. The temporal development of the penicillin-induced activity was divided into (a) a first phase characterized by an increased rate of neuronal firing, (b) a pre-paroxysmal phase wherein neurons began to fire clusters of action potentials and (c) a paroxysmal phase characterized by a discharge of action potential clusters. The excitatory responses to glutamate and to acetylcholine appeared to be enhanced during the first and pre-paroxysmal phases, whereas a loss of the excitatory effectiveness of both glutamate and acetylcholine occurred during the final paroxysmal phase. Forty nine of 69 neurons studied (71%) showed a decreased sensitivity to gamma-aminobutyrate during the first phase of penicillin iontophoresis. However, during this same time, glycine-induced inhibition was not decreased. During the second phase, gamma-aminobutyrate-induced inhibition was even less effective, and glycine started to lose effectiveness. During the third phase, both these inhibitory neurotransmitters failed to affect the neuronal activity. The other 29% of the neurons studied showed a general diminution to the actions of both gamma-aminobutyrate and glycine when penicillin-induced action potential clusters appeared. Our results suggest that penicillin interferes with gamma-aminobutyrate-mediated inhibition in a large proportion of cortical neurons of the rat. Furthermore, these cortical neurons show changes in the responses to both excitatory and inhibitory neurotransmitters that closely parallel the development of penicillin-induced activity.

[Preliminary considerations on the occurrence of antigens of the HLA system in a group of chronic glomerulonephritis patients]

80 patients affected by Cronic Glomerulonephritis have been typed for HLA-A-B-C locuses, using a standard NIH Microfinphotoxicity Technique. 66 healthy blood donors have been types as controls. A significantly increased frequency of HLA-Bw35 has been reported in the patients group. Further analysis is needed for definite conclusions about linkage between this disease and HLA antigens.