Effect of tilting on oxygenation in newborn infants.

Transcutaneous (tc) PO2 in newborn infants increased on head up tilting (median increase 0.5 kPa at term, 1.0 kPa preterm). Head down tilting was associated with an equivalent fall in tcPO2. There was no change in tcPCO2. Tilting of infants mechanically ventilated for respiratory distress syndrome or surgery produced no consistent change in PO2.     

Transcutaneous measurement of carbon dioxide tension: effect of sleep state in term infants

Transcutaneous measurement of carbon dioxide tension (tcPO2) was used to assess the effect of sleep state on arterial carbon dioxide tension (PaCO2) in infants. Initially, tcPCO2 was correlated with PaCO2 in 50 sick preterm and term neonates with indwelling arterial lines. At a skin electrode temperature of 42 degrees C, the correlation coefficient between tcPCO2 and PaCO2 was .95. In eight healthy term infants there was a small but significant decrease in tcPCO2 of 2 +/- 1 mm Hg (P less than .001) during active as compared to quiet sleep. This decrease in tcPCO2 was accompanied by a significant decrease in transcutaneous oxygen tension (tcPO2) of 5 +/- 4 mm Hg (P less than .02) as has been previously described. The simultaneous decrease of both tcPCO2 and tcPO2 appears to indicate ventilation/perfusion inequalities in these infants during active sleep. These findings illustrate that tcPCO2 can accurately predict PaCO2 in infants and that this is a useful technique for studying neonatal respiratory control during various stages of sleep.     

Histamine provocation in young, awake children with bronchial asthma, using a fall in oxygenation as the only indicator of a bronchial reaction

Bronchial provocation with histamine was performed in 11 boys and 6 girls, age range 2.7-7.4 y, with unspecific respiratory symptoms or bronchial asthma, using a fall in oxygenation as the only indicator of a bronchial reaction. In addition to transcutaneous oxygen tension (tcPO2), transcutaneous carbon dioxide tension (tcPCO2) was continuously monitored during the provocation procedure in order to identify possible changes in ventilation. A fall of 20% or more in the tcPO2 below a "floating" baseline value, defined as the highest tcPO2 value between the inhalations of histamine up to that point, was regarded as indicating a significant bronchial reaction. One child was excluded from the study because of an "early, false-positive" reaction due to hyperventilation during the inhalation, verified by a decrease in the tcPCO2 followed by a compensatory period of hypoventilation, resulting in a fall of more than 15% in the tcPO2 after the inhalation of saline. In the vast majority of the children, however, the tcPO2 values remained stable during the first dose stages of saline and histamine, with either a gradual fall immediately before or a distinct fall in conjunction with the reaction. The mean reaction concentration was significantly lower in the group of children with clinical asthma, 0.74 mg/ml, compared with the group of children with unspecific respiratory symptoms, 2.00 mg/ml (p = 0.03). In conclusion, a 20% fall in the tcPO2 can be used as the only indicator of a bronchial reaction during bronchial provocation tests in young, awake children. Changes in ventilation evaluated by monitoring tcPCO2, makes it possible to distinguish between a fall in oxygen tension due to an early, "false" reaction as a result of hypoventilation and a "true" bronchial reaction.     

Effects of metaproterenol on pulmonary mechanics, oxygenation, and ventilation in infants with chronic lung disease

Changes in pulmonary resistance, dynamic compliance, tidal volume, and transcutaneous PO2 and PCO2 after nebulized administration of metaproterenol were evaluated in eight newborn infants (birth weight 650 to 1060 g, gestational age 25 to 28 weeks) with chronic lung disease receiving mechanical ventilation. The infants were monitored continuously before and for 15 minutes after nebulization of metaproterenol during 3 consecutive days at mean age 34 days. There were significant increases in compliance, tidal volume, and tcPO2, and significant decreases in pulmonary resistance and tcPCO2. These data show that bronchospasm contributes significantly to the high pulmonary resistance in preterm infants with chronic lung disease and that metaproterenol is beneficial in the therapy of infants with chronic lung disease requiring mechanical ventilation.     

Transcutaneous oxygen and carbon dioxide levels and a clinical symptom scale for monitoring the acute asthmatic state in infants and young children

Measurement of transcutaneous PO2 and PCO2 in addition to a clinical symptom grading system was used to monitor the acute asthmatic attack in children under two years of age. tcPO2 was lowered already at signs of mild obstruction and decreased in parallel with clinical deterioration. tcPCO2 was almost unchanged at mild to moderate obstructive symptoms. With clinical deterioration tcPCO2 rose steadily. An increase of the oxygen concentration to 30-40% in the inspired air increased tcPO2, on the average by 70%, but did not change the tcPCO2, level. Continuous recording of tcPO2 and tcPCO2 as well as the clinical grading system are valuable tools when monitoring severely obstructive infants and young children.     

Chronic respiratory failure after acquired cytomegalovirus infection in a very low birthweight infant

The case of a female infant who developed chronic respiratory failure after an acquired cytomegalovirus (CMV) infection is presented here. She was a very low birthweight (VLBW) infant and was free from oxygen supplement until 2 months after birth. Interstitial pneumonia occurred at 2 months of age, and her respiratory condition gradually deteriorated. A chest roentgenogram at 4 months revealed hyperinflation and reticular shadow, similar to that of severe chronic lung disease (CLD) in preterm infants. She was mechanically ventilated because of progressive respiratory deterioration, and oxygen dependency continued for 5 months after extubation. There are several previous reports of CMV pneumonia in term neonates or infants. However, there appears to be no published report on the pulmonary sequelae of CMV pneumonia in VLBW infants. The present case seems to indicate that acquired CMV pneumonia in VLBW infants causes chronic respiratory failure even when mechanical ventilation is not administered, and this respiratory failure is very similar to CLD in clinical symptoms and chest roentgenogram.     

Routine daily chest radiographs in ventilated, very low birth weight infants

The aim of this study was to assess the frequency of new abnormalities on routine chest radiographs of ventilated, very low birth weight (VLBW) infants during the acute stage of their illness. Infants were identified who had had at least three daily routine chest radiographs. The appearance of their subsequent radiographs was compared to that obtained on the 1st day of ventilatory support and the timing of new abnormalities (malposition of the endotracheal or nasogastric tube, pulmonary interstitial emphysema, pleural effusion, pulmonary oedema, lobar collapse or consolidation) noted. A total of 100 radiographs were examined from 30 VLBW infants, median gestational age 27 weeks (range 23–32 weeks). New abnormalities were present on the radiographs of 24 infants and on 50% of the radiographs examined. The commonest abnormalities noted were pulmonary interstitial emphysema, collapse and consolidation. Conclusion Routine daily chest radiographs in mechanically ventilated, very low birth weight infants during the acute stage of their respiratory illness can yield new information important in patient care, new abnormalities being demonstrated in 50% of radiographs examined. Received: 26 June 2000 / Accepted: 27 September 2000     

Early use of Nasal-BiPAP in two infants with Congenital Central Hypoventilation syndrome

Aim: To reduce the problems caused by prolonged artificial ventilation in babies with Congenital Central Hypoventilation syndrome (CCHS). Methods: Two term infants with CCHS, weighing 4030 g and 3100 g, respectively, at the beginning of treatment and aged 53 and 31 d, respectively, were successfully ventilated with a Nasal Bilevel Positive Airway Pressure (N-BiPAP) device. Results: In the first patient the tcPO ₂ recordings (mean ± SD) during sleep were 46 ± 12 mmHg before using N-BiPAP and 58 ± 13 mmHg after using the device, while those for tcPCO ₂ were 75 ± 9 mmHg and 49 ± 11 mmHg, respectively. In the second patient tcPO ₂ during sleep was 42 ± 3 mmHg before, and 55 ± 5 after N-BiPAP, and for tcPCO ₂ the recordings were 119 ± 24 mmHg and 55 ± 6 mmHg, respectively, showing a significant improvement. One infant had persistent gastro-oesophageal reflux, and frontal skin abrasion caused by the face mask. Nevertheless, these complications did not necessitate the discontinuation of N-BiPAP ventilation, thus precluding prolonged use of intubation and tracheotomy.

Conclusion: In infants with CCHS, early use of non-invasive, positive-pressure ventilation with N-BiPAP, in association with careful monitoring, can decrease problems caused by prolonged intubation and tracheotomy.     

Cerebral and mesenteric tissue oxygenation by positional changes in very low birth weight premature infants

Aim

There has been no clear consensus of the appropriate positioning in preterm infants. We aimed to evaluate the changes of cerebral and mesenteric tissue oxygenation in three different positions, by near infrared spectroscopy (NIRS), in stable very low birth weight (VLBW) infants of postnatal > 30 days.

Methods

NIRS monitoring of cerebral and mesenteric tissue oxygenation in three different positions was performed in 29 stable preterm newborns in neonatal intensive care unit (NICU). The patients were observed in three different positions consecutively, each lasting for 4 h. The demographic features, cerebral and mesenteric tissue oxygenation with positional changes and feeding periods were recorded.

Results

Mean gestational age, mean birth weight and mean postnatal age of the patients were 27.6 ± 1.7 weeks, 1046 ± 308 g and 42.4 ± 15.7 days, respectively. There were no statistically significant differences in cerebral and mesenteric tissue regional SO₂ values in each position (p = 0.954 and p = 0.151, respectively). The values of cerebral and mesenteric tissue regional SO₂ before and after feeding did not show any statistically significant difference in each position.

Conclusions

Clinically stable very low birth weight infants are able to maintain a stable cerebral and mesenteric tissue oxygenation in different positions, both before and after feeding. Positional changes seem to be safe in VLBW stable infants and this influence should be considered in care of these patients in the NICU.Clinical Trials Identification Number: NCT01255189.     

极早产儿俯卧位机械通气对呼吸功能的影响

目的 探讨极早产儿俯卧位机械通气对呼吸功能的影响。方法 83例经口气管插管机械通气极早产儿随机分为仰卧位组和俯卧位组,4例退出研究,79例完成治疗和观察（仰卧位组37例,俯卧位组42例）,以容量辅助/控制模式机械通气。俯卧位组患儿每仰卧位通气4 h行俯卧位通气2 h。分组干预之前以及分组干预后仰卧位组每6 h、俯卧位组每于转换为俯卧位后的1 h,分别记录呼吸机参数、动脉血气分析和生命体征。结果 俯卧位组FiO₂、气道峰压,平均气道压、机械通气时间低于仰卧位组,差异有统计学意义（P < 0.05）;两组潮气量、呼气末正压的差异无统计学意义（P > 0.05）;俯卧位组的PO₂/FiO₂比值高于仰卧位组,而氧合指数、呼吸频率较低,差异均有统计学意义（P < 0.05）。两组PaO₂、pH、BE、心率和有创动脉血压平均压的差异无统计学意义（P > 0.05）。结论 俯卧位与仰卧位交替通气能改善机械通气极早产儿的氧合功能,降低吸入氧体积分数,缩短机械通气时间。     

Bronchopulmonary dysplasia in very low birthweight infants

The incidence, clinical presentation and severity of bronchopulmonary dysplasia (BPD) in 110 consecutive very low birthweight (VLBW) infants admitted to the National University Hospital Neonatal Intensive Care Unit between October 1985 and January 1989 is reviewed. Thirty-two infants died, giving an overall survival rate of 70.9%. Sixty infants (54.4%) required mechanical ventilation in the first week of life; 24 (40%) of these infants died. Of the 36 survivors, 23 required oxygenation at 28 days of life and 21 fulfilled the criteria for BPD (35% of the 60 ventilated and 58% of the survivors). The incidence of BPD in all VLBW infants is 19% and of VLBW survivors 27%. Birthweight and gestational age appear to be important determinants. All the survivors in the 501-750 g birthweight group developed BPD compared to 6.25% in those above 1250 g. None of those greater than 30 weeks gestation developed BPD. Two forms of BPD were observed; the 'severe' group presented radiologically with chest radiographs characteristic of Stage IV BPD, while the 'mild' group with small or normal sized lungs demonstrated irregular strands of radio-densities alternating with areas of normal or increased lucency. The duration of mechanical ventilation and oxygen dependency were significantly longer in the 'severe' group, with the mean maximum peak inspiratory pressure, mean airway pressure, and FiO2 required in the first week of life being also significantly higher. Hyaline membrane disease was the main cause of respiratory failure requiring ventilation. The other causes were persistent pulmonary hypertension (1) and apnoea of prematurity (3); all of the latter developed only mild BPD.(ABSTRACT TRUNCATED AT 250 WORDS)     

极/超低出生体重儿生后早期腹部局部组织氧饱和度变化趋势的前瞻性研究

目的 探讨极/超低出生体重儿（very/extremely low birth weight infant,VLBWI/ELBWI）出生后的腹部局部组织氧饱和度（abdominal regional oxygen saturation,A-rSO₂）变化趋势。 方法 选取2019年9月至2021年5月在新生儿重症监护室住院的VLBWI/ELBWI作为研究对象。利用近红外光谱技术,从出生后第1天开始每天监测A-rSO₂,共监测4周。并根据出生胎龄分为较低胎龄组（<29周组）及较高胎龄组（≥29周组）,对两组VLBWI/ELBWI生后4周内的A-rSO₂进行比较分析。 结果 共纳入VLBWI/ELBWI 63例,其中<29周组30例,≥29周组33例。63例VLBWI/ELBWI生后2周内A-rSO₂呈现波动变化：生后第1天为最低值（47.9%）,后逐渐升高,第4天达最高峰（67.4%）,第5~9天逐渐下降,然后再次上升,至出生2周后趋于稳定。≥29周组出生后第1周及第2周A-rSO2均高于<29周组,差异有统计学意义（P<0.05）。出生第3周及第4周两组A-rSO₂均值比较差异无统计学意义（P>0.05）。 结论 VLBWI/ELBWI的A-rSO₂在出生后最初2周随日龄增加存在波动变化,2周后趋于稳定;生后2周内的A-rSO₂与胎龄相关。     

Underestimation of arterial oxygen tension by transcutaneous electrode with increasing age in infants.

To investigate the effect of increasing gestational and postnatal age on the relation between transcutaneous oxygen tension (tcPO2) and arterial oxygen tension (PaO2) 160 simultaneous measurements of tcPO2 and PaO2 tensions were made on 42 infants born at 24-41 weeks'' gestation and aged 0-32 weeks from birth. Irrespective of gestational age a progressive fall in the tcPO2:PaO2 ratio with increasing postnatal age was found. At all postnatal ages tcPO2:PaO2 tended to be lower in the more mature infants.     

Nasal high-frequency ventilation for premature infants

Aim: To assess the use of nasal high‐frequency ventilation (HFV) to provide noninvasive ventilatory support for very low birthweight (VLBW) infants. Study Design: VLBW infants, >7 days of age on nasal continuous positive airway pressure (CPAP), were placed on nasal HFV for 2 h using the Infant Star high‐frequency ventilator (Mallinckrodt, Inc., St. Louis, MO, USA). Mean airway pressure was set to equal the previous level of CPAP, and amplitude was adjusted to obtain chest wall vibration. Capillary blood was sampled before starting HFV and after 2 h to determine change in pH and partial pressure of carbon dioxide (pCO₂). Results: Fourteen subjects were studied, 10 males and 4 females. Gestational age was 26–30 weeks (median 27). Age at study was 18–147 days (median 30). Median birth weight was 955 g; median weight at study was 1605 g. Nasal CPAP pressure was 4–7 cm H₂O (mean 5). Amplitude was 30–60 (median 50). After 2 h, PCO₂ (mean 45 torr) was significantly lower than initial PCO₂ (mean 50 torr) (p = 0.01), and pH had increased significantly (7.40 vs. 7.37, p = 0.04). Conclusions: Nasal HFV is effective in decreasing pCO₂ in stable premature infants requiring nasal CPAP support. Long‐term use of nasal HFV requires further study.     

Randomised controlled trial of respiratory system compliance measurements in mechanically ventilated neonates

AIM—To determine whether outcomes of neonatal mechanical ventilation could be improved by regular pulmonary function testing.
METHODS—Two hundred and forty five neonates, without immediately life threatening congenital malformations, were mechanically ventilated in the newborn period. Infants were randomly allocated to conventional clinical management (control group) or conventional management supplemented by regular measurements of static respiratory system compliance, using the single breath technique, with standardised management advice based on the results.
RESULTS—Fifty five (45%) infants in each group experienced one or more adverse outcomes. The median (quartile) durations of ventilation and oxygen supplementation were 5 (2-12) and 6 (2-34) days for the control group, and 4 (2-9) and 6 (3-36) days for the experimental group (not significant). On post-hoc secondary analysis, control group survivors were ventilated for 1269 days with a median (quartile) of 5 (2-13) days, and experimental group survivors were ventilated for 775 days with a median (quartile) duration of 3 (2-8) days (p=0.03).
CONCLUSIONS—Although primary analysis did not show any substantial benefit associated with regular measurement of static respiratory system compliance, this may reflect a type II error, and a moderate benefit has not been excluded. Larger studies are required to establish the value of on-line monitoring techniques now available with neonatal ventilators.

     

俯卧位通气对小儿急性肺损伤的疗效

目的评价俯卧位通气对小儿急性肺损伤(ALI)的临床疗效。方法2006年5月-2007年12月苏州大学附属儿童医院儿科重症监护病房收住的17例ALI患儿,在持续镇静下俯卧位通气4h,机械通气模式为压力控制模式(PCmode),以监测呼出潮气量6～8mL/kg反馈调节控制压力,吸气时间0.6～1.0s,呼吸频率28～42次/min,吸入氧体积分数400～1000mL/L,呼气末正压6～16cmH2O(1cmH2O=0.098kPa)。监测0、1、4h及恢复仰卧位通气4h的呼吸循环指标,并进行比较。采用SPSS13.0软件进行统计学分析。结果在实施俯卧位通气1、4h及恢复仰卧位通气4h,氧合指数[pa(O2)/FiO2]和pa(O2)均较实施俯卧位通气前显著升高(Pa<0.05),俯卧位通气4h和恢复仰卧位通气4h时的尿量也有增加(Pa<0.05)。而心率、平均动脉血压、动脉血二氧化碳分压、呼吸系统动态顺应性、呼吸道阻力、呼吸道峰压等比较差异均无统计学意义。结论俯卧位通气可改善ALI患儿的氧合,增加尿量,恢复仰卧位通气后氧合改善,尿量增加仍持续存在。     

Transcutaneous Measurement of Oxygen Tension in Infants with Hyaline Membrane Disease

Barr, P. A. (1979). Aust. Paediatr. J. , 15, 3–6. Transcutaneous measurement of oxygen tension in infants with hyaline membrane disease . Transcutaneous oxygen tension (tcPO2) using the Roche electrode, was compared with arterial oxygen tension (PaO2) from an indwelling arterial catheter or cannula in thirty-two infants with hyaline membrane disease. tcPO2 monitoring was performed by neonatal intensive care nurses for as long as seven days. Although the correlation of tcPO2 with PaO2 was good (r 0.713, P <.001), the tcPO2 monitor frequently failed to detect hypoxaemia and hyperoxaemia. Seventy-eight per cent of recorded PaO2 values < 50 mmHg were associated with tcPO2 values ≥ 50 mmHg and 41% of PaO2 values > 90 mmHg were associated with tcPO2 values ≤ 90 mmHg. tcPO2 measurement was not an acceptable alternative to PaO2 measurement. The incidence of hyperoxaemia in seven tcPO2 monitored infants with severe hyaline membrane disease (HMD) (5%) was significantly less than in five unmonitored infants with equally severe HMD (32%) (X², P < .001). tcPO2 monitoring was useful as a PaO2 trend recorder.     

Home oxygen therapy following neonatal intensive care

In a 12-month period 28 of 164 consecutive very low birthweight (VLBW) infants receiving intensive care within 48 h of birth at King's College Hospital developed chronic lung disease, (oxygen dependence beyond 28 days of age). Fifteen of the 28 infants were eligible for home oxygen therapy, but this was only practical, because of home circumstances, in 8 infants (4.9%). These 8 infants received home oxygen therapy. One further infant, born at term and suffering from pulmonary hypoplasia was also discharged home on oxygen therapy. Two infants subsequently required readmission due to a deterioration in their respiratory status and died. Three others required re-admissions (total duration 32 days) for respiratory problems. The median duration of home oxygen therapy was 17 weeks (range 4-486 days). We conclude that home oxygen therapy is needed by only a very small number of preterm infants and is appropriate for only a proportion of them. Parents need to be counselled carefully regarding the possibility that the need for oxygen might be protracted.     

Colloid infusion in the perinatal period and abnormal neurodevelopmental outcome in very low birth weight infants

In very low birth weight (VLBW) infants, colloid infusion is associated with impaired perinatal lung function and increased oxygen dependency duration. The aim of this study was to determine whether perinatal colloid infusion was associated with abnormal neurodevelopmental outcome. All perinatal fluid input (crystalloid and colloid) given to VLBW infants entered into a randomised trial was recorded. At 1 and/or 2 years, the neurodevelopmental status of VLBW infants was routinely assessed. Of 131 survivors, median gestational age 27 weeks (range 23-33 weeks), 95 were seen at follow-up. Nineteen had abnormal neurodevelopmental outcome and differed significantly from the rest of the cohort with regard to their birth weight, magnitude of colloid infusion received and the proportions who had received postnatal steroids, suffered prolonged oxygen dependency or having had intracerebral haemorrhage/periventricular leucomalacia development. Regression analysis demonstrated that only colloid infusion related significantly to abnormal neurodevelopmental outcome independent of other variables. CONCLUSION: These data suggest that colloid infusion should be used with caution in the perinatal period.     

Prognostic factors for walking attainment in very low-birthweight preterm infants

The purpose of this study was to compare the age of walking attainment between very low-birthweight (VLBW) preterm infants and normal term infants, and to determine the variables that affect the walking attainment in VLBW infants. Ninety-six VLBW preterm infants and 82 normal term infants were prospectively followed to determine their age of walking attainment and to monitor gross motor development with sequential clinic visits at 6, 9, 12 and 18 months corrected age. Perinatal and sociodemographic data were collected through review of medical records. The VLBW infants were significantly older at attainment of walking (median 14 months) than the term infants (median 12 months) after correction for prematurity. By the age of 18 months, all term infants had attained walking ability; while 11% of VLBW infants were still unable to walk. Multivariate proportional hazards regression analysis revealed that low gestational age was significantly associated with late attainment of walking in VLBW infants. With the adjustment for gestational age, prolonged ventilation (or oxygen therapy) and severe retinopathy of prematurity were significant predictors of late walking attainment. Our findings indicate that VLBW preterm infants have an increased risk of delayed attainment of walking. Furthermore, the contribution of low gestational age to the delayed walking attainment in VLBW infants may occur via the plausible pathways of neonatal respiratory distress and severe retinopathy of prematurity.