The proper tidal volume target using volume guarantee ventilation in the course of neonatal respiratory distress syndrome: a crucial endpoint

Volume guarantee ventilation (VGV) is an optional ventilation mode which has become the most widely and extensively studied in the last 10 years in premature infants. Nonetheless, theoretical expected endpoints are intriguing and even though VGV has not yet become 'the' standard ventilation mode, a great deal of information has been acquired and stored. In our experience, VGV during the course of respiratory distress syndrome is useful and can be considered a standard ventilation mode. Weaning occurs in real time as described earlier, and synchronized intermittent positive pressure ventilation and pressure support ventilation (PSV) seem to be the preferred combined modes. Management during the acute phase requires more care since several sudden changes take place in both the lung mechanics and clinical behavior. The software is designed to protect the lung, and subsequently, sudden changes in lung compliance following iatrogenic procedures such as surfactant administration are powerfully counteracted. VGV has been extensively studied and the proposed algorithm has been found to function as planned. Although the 'superiority' of one method over another cannot be demonstrated, the use of new technologies require 'a staff learning curve' and homogeneity of treatment, while at the same time other factors, such as patient heterogeneity or illness phase, should be taken into due account.

Maternal dietary PUFAs intake and human milk content relationships during the first month of lactation

Maternal dietary fatty acids (FFAs) intake and corresponding human milk composition relationships have been assessed throughout the first month of lactation in 34 lactating women consecutively enrolled. All mothers were on their habitual diet. Food records (95 items) were administered to the mothers, six-times during the first month of lactation (1 day after delivery, 4, 7, 14, 21, and 28 days after colostrum appearance) and referred to maternal dietary intake of the day before. Milk collected on day 1 was considered as colostrum, day 4 and 7 samples as transitional milk, and day 14, 21 and 28 samples as mature milk. Five gas chromatographic analyses were performed on each sample. Statistics were made using Friedman's and Pearson's test. Maternal dietary saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) were significantly related to the corresponding milk pattern in the phase of transitional milk (P<0.01), while total polyunsaturated (PUFAs) content was significantly related only to the mature milk (P<0.01); in this phase about 42% of the variations occurring in PUFAs milk content can be related to variation of maternal PUFAs dietary intake. The results in the present study provide evidence of the relationships between maternal diet and milk composition. The degree of correlation between maternal diet and PUFAs milk content increases throughout milk maturational process and reaches significance only in mature milk. This would imply that advancing lactation, milk PUFAs provision sources gradually shift from adipose tissue catabolism to maternal diet.

A randomised control study comparing the Infant Flow Driver with nasal continuous positive airway pressure in preterm infants

OBJECTIVE

To compare the effectiveness of the Infant Flow Driver (IFD) with single prong nasal continuous positive airway pressure (nCPAP) in preterm neonates affected by respiratory distress syndrome.

DESIGN

Randomised controlled study.

PATIENTS

Between September 1997 and March 1999, 36 preterm infants who were eligible for CPAP treatment were randomly selected for either nCPAP or IFD and studied prospectively for changes in oxygen requirement and/or respiratory rate. The requirement for mechanical ventilation, complications of treatment, and effects on mid-term outcome were also evaluated.

RESULTS

Use of the IFD had a significantly beneficial effect on both oxygen requirement and respiratory rate (p < 0.0001) when compared with nCPAP. Moreover, O(2) requirement and respiratory rate were significantly decreased by four hours (p < 0.001 and p < 0.03 respectively). The probability of remaining supplementary oxygen free over the first 48 hours of treatment was significantly higher in patients treated with the IFD than with nCPAP (p < 0.02). IFD treated patients had a higher success (weaning) rate (94% v 72 %) and shorter duration of treatment (49.3 (31) v 56 (29.7) hours respectively; mean (SD)), although the difference was not significant.

CONCLUSIONS

IFD appears to be a feasible device for managing respiratory distress syndrome in preterm infants, and benefits may be had with regard to oxygen requirement and respiratory rate when compared with nCPAP. The trend towards reduced requirement for mechanical ventilation, shorter clinical recovery time, and shorter duration of treatment requires further evaluation in a multicentre randomised clinical trial.

Fatty acid composition of human milk in Italy

The fatty acid composition of breast milk from 20 Italian women, delivering at term and on ad libitum diets, was analyzed with high-resolution gas chromatography. Milk samples were collected twice a day, on the 1st, 4th, 7th, 14th, 21st and 28th day after colostrum appearance. No significant differences were detected between the two daily samples. During the maturation process a significant reduction in long-chain polyunsaturated fatty acids of the n-6 series (p = 0.002) and n-3 series (p = 0.005) was recorded, particularly in arachidonic acid (p = 0.035), docosatetraenoic acid (p = 0.035) and docosahexaenoic acid (p = 0.032). The linoleic acid/n-6 and alpha-linolenic acid/n-3 ratios increased (p = 0.024 and p = 0.037), while the docosatetraenoic/docosahexaenoic acid ratio decreased (p = 0.032). The fatty acid composition of mature milk was the following: saturated 45.50%; unsaturated 54.51%; monounsaturated 42.69%; polyunsaturated 11.82%; long-chain polyunsaturated 1.27%; linoleic acid 9.79%, and alpha-linolenic acid 0.36%. The fatty acid composition of milk collected from Italian women appears similar to that of women in other southern European countries and, therefore, could reflect dietary habits.