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F Pohlandt

Publications and source records attributed to F Pohlandt.

At least 55 records · Page 3Linked to original sources
PubMed1999

Single-dose dexamethasone treatment of hypotension in preterm infants.

OBJECTIVE: To test the efficacy of single-dose dexamethasone (DXM) in the management of severe arterial hypotension of newborn infants. Our hypothesis was that epinephrine infusions could be discontinued in 70% of patients within 12 hours after DXM administration compared with 10% in the placebo group. STUDY DESIGN: Twenty preterm infants (median birth weight 690 g, gestational age 28 weeks, age at intervention 2 days) who did not respond to a standardized treatment protocol (blood/colloid followed by dopamine infusion stepwise increased to 15 micrograms/kg and minute) were started on an epinephrine infusion and were randomly allocated to receive either DXM (0.25 mg/kg) or placebo intravenously. The primary outcome criterion was the need for an epinephrine infusion 12 hours after treatment. RESULTS: Three infants were excluded. Epinephrine infusion was discontinued in 5 of 8 infants with DXM but in only 1 of 9 infants in the control group. The duration of epinephrine infusion was significantly shorter in the DXM group (exact log-rank test, P =. 023). CONCLUSIONS: DXM was effective for the management of severe arterial hypotension in preterm infants not responding to standardized treatment.

Adrenergic Agonists↗
PubMed1999

Randomized comparison of high-frequency ventilation with high-rate intermittent positive pressure ventilation in preterm infants with respiratory failure.

OBJECTIVE: In a randomized, controlled, multicenter trial, we tested the hypothesis that high-frequency ventilation (HFV) with a high lung volume strategy results in fewer treatment failures than intermittent positive pressure ventilation (IPPV) with high rates and low peak inspiratory pressures. STUDY DESIGN: Infants with a gestational age between >/=24 weeks and <30 weeks, requiring mechanical ventilation within 6 hours of birth, were randomly assigned to receive either IPPV or HFV until 240 hours after randomization, extubation, or meeting treatment failure criteria. Treatment failure, the primary end point, was determined when air leaks, an oxygenation index >35 to 45 (depending on gestational age), death, or chronic lung disease occurred. Chronic lung disease was defined as persistent requirement of mechanical ventilation, continuous positive airway pressure, or supplemental oxygen at a postmenstrual age of 36 weeks. Secondary end points included the incidence of intracranial hemorrhage. RESULTS: The third scheduled interim analysis led to termination of the trial after recruitment of 284 infants. Treatment failure criteria were met by 46% of infants receiving IPPV and 54% of infants receiving HFV (1-tailed primary hypothesis, P =.92; 2-tailed chi2 test, P =.15). Air leaks occurred in 31% and 42% (P =.042), CLD in 23% and 25%, and grade 3-4 intracranial hemorrhage in 13% and 14% of IPPV-treated and HFV-treated patients, respectively. The mortality rate before discharge was 10% in both groups. CONCLUSION: HFV with a high lung volume strategy did not cause less lung injury in preterm infants than IPPV with a high rate and low peak inspiratory pressures.

Bronchopulmonary Dysplasia↗
PubMed1999

Protein hydrolysate formula maintains homeostasis of plasma amino acids in preterm infants.

BACKGROUND: Plasma amino acid concentrations were measured in preterm infants who were fed either a new hydrolyzed cow's milk protein formula or a standard preterm infant formula. It was hypothesized that feeding with the hydrolysate results in preprandial amino acid concentrations that are significantly different from the concentrations found when feeding with the standard formula. METHODS: Fifteen preterm infants, median gestational age, 29 weeks (range, 24-32 weeks); birth weight, 1241 g (range, 660-1900 g); and postnatal age, 18 days (range, 7-54 days) receiving full enteral feedings (>150 ml/kg x day), were enrolled. The intervention was randomized allocation to the formula with hydrolyzed or natural cow's milk protein (the whey/casein ratio was 60:40 in both formulas). In a crossover design, each formula was fed for 5 days, and plasma amino acids were analyzed on day 4 or 5 of each 5-day period. RESULTS: In spite of the 12% higher amino acid intake with hydrolysate formula, the median individual plasma amino acid concentrations were virtually identical with both formulas, and they were within the 10th and the 90th percentile of the reference of levels in the umbilical cord artery after elective cesarean delivery or of breast-fed newborn infants. The median concentrations of lysine and aspartic acid were higher with hydrolyzed formula feeding (p<0.05; two-tailed Mann-Whitney test). With both formulas, single amino acid concentrations were out of the reference values. CONCLUSION: Virtually identical plasma amino acid concentration patterns were measured with the new hydrolyzed preterm infant formula and the standard preterm infant formula, but longitudinal studies are required before the studied protein hydrolysate can be recommended for preterm feeding in general.

Amino Acids↗
PubMed1999

Comparison of procalcitonin with interleukin 8, C-reactive protein and differential white blood cell count for the early diagnosis of bacterial infections in newborn infants.

OBJECTIVE: To evaluate procalcitonin (PCT) as a test for early diagnosis of bacterial infections (BI) in newborn infants and to compare the results of PCT with those of interleukin 8 (IL-8), C-reactive protein (CRP) and differential white blood cell count. STUDY DESIGN: PCT was prospectively measured along with IL-8, CRP and differential white blood cell counts and blood cultures in 197 newborn infants at the first suspicion of bacterial infection. PCT, IL-8, CRP and differential white blood cell counts were analyzed for sensitivity, specificity and positive and negative predictive values after receiver operating characteristic curve analysis for best thresholds. The kinetics of PCT was determined in infants with and without BI. RESULTS: Forty-six infants were diagnosed clinically as having BI, of whom 9 had BI with positive blood cultures. At a cutoff value of 0.50 microg/l, PCT detected combined culture-proved and clinical BI with a sensitivity of 57% (95% confidence interval, 41%, 71%) and a specificity of 66% (95% confidence interval, 57%, 74%). The combination of IL-8 > or =70 ng/l and/or CRP >10 mg/l achieved a sensitivity of 91% (95% confidence interval, 79%, 98%) and a specificity of 73% (95% confidence interval, 64%, 81%). PCT values of infected and not infected infants tended to rise for 24 h after initial evaluation and then decreased. CONCLUSION: The combination of IL-8 and CRP is more reliable than PCT as a test for early diagnosis of BI in newborn infants.

Bacterial Infections↗
PubMed1999

Reference range for serum cortisol in well preterm infants.

AIM: To establish a reference range for serum cortisol concentrations in preterm infants with a gestational age of less than 30 weeks during the first two weeks of life. METHODS: Infants were prospectively classified by the following exclusion criteria: surfactant administration, arterial hypotension, acute or uncontrolled infection, ventricular haemorrhage II degrees or above, serum glucose < 2.2 mmol/l, exchange transfusion, stress as a result of any kind of examination or nursing for at least 4 hours before blood sampling. The cortisol value was measured once using radioimmunoassay in each infant. RESULTS: In appropriate for gestational age (AGA) infants (n = 37, median gestational age 27.7 weeks, median birthweight 1030 g) the distribution of the cortisol concentrations was non-Gaussian. These had a nearly normal distribution, when log(10) values of the data were used. The points determined by mean (2 SD) on the logarithmic scale were transformed back to the original units to provide a reference range: 73-562 nmol/l. Gestational age was significantly (p = 0.033) associated with cortisol values (log(10)) with a regression coefficient (standard error) of -0.045 (0.020). Small for gestational age (SGA) infants (n = 8) had significantly higher cortisol values (median 357 nmol/l) than AGA infants (median 199 nmol/l) (p=0.028). CONCLUSIONS: There is a strictly defined reference range of serum cortisol concentrations in AGA preterm infants.

Gestational Age↗
PubMed1999

17Beta-estradiol and progesterone supplementation in extremely low-birth-weight infants.

During pregnancy, 17beta-estradiol (E2) and progesterone (P) plasma concentrations increase up to 100-fold. The fetus is exposed to these increasing amounts of E2 and P. Within 1 d after delivery, E2 and P concentrations fall to nonpregnancy concentrations in the mother and the infant. Extremely premature infants are cut off from the placental supply of E2 and P at a very early developmental stage, and therefore they suffer from this deprivation for a longer period than infants born at term. Nothing is known about the consequences of this deprivation. The purpose of this study was to investigate how intrauterine concentrations of E2 and P could be maintained after birth. In 13 infants with a median gestational age of 26.4 wk (24.1-28.7), a phospholipid-stabilized soybean oil emulsion available for parenteral nutrition that contains different amounts of E2 and P was continuously administered, starting within the first postnatal hours. The supplementation was continued as long as venous access was indicated but not longer than 6 wk (median 20 d, 12-44). To maintain intrauterine plasma concentrations of 2000-6000 pg/mL E2 and 300-600 ng/mL P, 2.30 mg x kg(-1) x d(-1) E2 (1.13-3.42 mg x kg(-1) x d(-1)) and 21.20 mg x kg(-1) x d(-1) P (11.23-27.36 mg x kg(-1) x d(-1)) were needed. We conclude that supplementation of E2 and P to maintain intrauterine concentrations in extremely premature infants is possible intravenously. The infants in this study are enrolled in a randomized, controlled pilot study to evaluate the potential benefits of E2 and P supplementation.

Dietary Supplements↗
PubMed1999

Effects of postnatal estradiol and progesterone replacement in extremely preterm infants.

The fetus is supplied from the placenta with estradiol (E2) and progesterone (P) in increasing amounts during gestation. After delivery of a premature infant, placental supply is disrupted, resulting in a rapid decrease in E2 and P. Replacement of these placental hormones may restore intrauterine conditions and may be beneficial for bone mineral accretion, clinical course, and outcome. Thirty female infants with a median gestational age of 26.6 weeks (between 24.1-28.7) and a birth weight of 675 g (370-990) were randomized to receive E2 and P replacement, aiming to maintain plasma levels equaling the intrauterine levels, or no replacement. The E2 and P replacement was started iv and was followed by transepidermal administration for a total duration of 6 weeks. Repeated measurements included plasma levels of E2, P, FSH, and LH; uterine volume; calcium and phosphorus in spot urine specimens; and bone mineral accretion by single photon absorption densitometry. Further, the incidence of chronic lung disease and various clinical outcome data were recorded. The plasma levels of E2 and P were within the intrauterine range with median replacements of 2.30 mg/kg x day E2 (1.13-6.23) and 21.20 mg/kg x day P (11.23-27.36), iv. Three- and 6-fold higher doses of E2 and P were needed via the transepidermal route. The uterine volumes increased, and FSH and LH as indicators for biological effectiveness were significantly lowered with replacement. The bone mineral accretion rates tended to be higher, and the incidence of chronic lung disease tended to be lower (0% vs. 29%; P = 0.097). E2 and P replacement via iv and transepidermal routes is capable of maintaining plasma levels as high as those in utero with biological effectiveness. Trends toward improved postnatal bone mineral accretion and less chronic lung disease were found with the hormone replacement. Further and more extensive studies are warranted to address the role of this new approach in the care of extremely premature infants.

Birth Weight↗
PubMed1999

Delivery room management of extremely low birth weight infants: spontaneous breathing or intubation?

OBJECTIVE: To study the effect of two different delivery room (DR) policies on the rate of endotracheal intubation and mechanical ventilation (EI/MV) and short term morbidity in extremely low birth weight infants (ELBWI; <1000 g, >/=24 weeks). METHODS: Retrospective cohort study of 123 inborn ELBWIs born in 1994 and in 1996. DR policies have changed. Until 1994, ELBWIs were intubated immediately after delivery when presenting the slightest signs of respiratory distress or asphyxia after initial resuscitation using a face mask and a handbag. During 1995, the guidelines for respiratory support were changed. In 1996, continuous (15 to 20 seconds), pressure controlled (20 to 25 cm H2O) inflation of the lungs using a nasal pharyngeal tube, followed by continuous positive airway pressure (CPAP; 4 to 6 cm H2O) was applied to all ELBWIs immediately after delivery to establish a functional residual capacity and perhaps to avoid EI/MV. In addition to the changes in respiratory support, the prevention of conductive and evaporative heat loss was improved in 1996. For analysis of morbidity and mortality, infants were matched for gestational age and birth weight. RESULTS: The rate of EI/MV in the DR decreased from 84% in 1994 to 40% in 1996. In 1996, 25% of the ELBWIs were never intubated (7% in 1994), but 35% of the ELBWIs needed secondary EI/MV, primarily because of respiratory distress syndrome (RDS). Initial ventilator settings, ventilator days, mortality, and morbidity were not different between ELBWIs with EI/MV in the DR and infants with secondary EI/MV attributable to RDS in the intensive care unit. ELBWIs with no EI/MV that was caused by RDS had a lower morbidity (ie, bronchopulmonary dysplasia, intraventricular hemorrhage >grade 2 and/or periventricular leukomalacia), mortality, and fewer hospital days (mean: 79 vs 105 days). The incidence of gastrointestinal adverse effects like feeding intolerance or necrotizing enterocolitis was not increased in 1996. PaCO2 was significantly higher at admission to the neonatal unit in ELBWIs with CPAP in 1996 (54 +/- 15 mm Hg, 7.2 +/- 2.0 kPa) compared with infants with EI/MV in 1994 (38 +/- 11 mm Hg, 5.1 +/- 1. 5 kPa. A total of 26% of spontaneously breathing infants had hypercapnia (PaCO2 >/=60 mm Hg [8.0 kPa]), compared with 7% of infants with EI/MV in 1994. Within the first few hours of life, PaCO2 decreased to 46 (32 to 57) mm Hg (6.1 [4.3 to 7.6] kPa) in never intubated ELBWIs (n = 17), but increased to 70 (57 to 81) mm Hg (9.3 [7.6 to 10.8] kPa) in ELBWIs (n = 14) with RDS and secondary EI/MV (age 5.5 [1 to 44] hours). CONCLUSIONS: In our setting, the individualized intubation strategy in the DR restricted EI/MV to those ELBWIs who ultimately needed it, without increasing morbidity or mortality in infants with secondary EI/MV attributable to RDS. We speculate that an individualized intubation strategy of the ELBWI is superior to immediate intubation of all ELBWIs with slight signs of respiratory distress after birth.

Cohort Studies↗
PubMed1999

Reduction of unnecessary antibiotic therapy in newborn infants using interleukin-8 and C-reactive protein as markers of bacterial infections.

OBJECTIVE: To examine whether the determination of interleukin 8 (IL-8) and C-reactive protein (CRP) in neonates with suspected nosocomial bacterial infection (NBI) is feasible and cost-effective in reducing antibiotic therapy. METHODS: Between April 1996 and May 1997, IL-8 was measured 260 times along with blood cultures, CRP, and immature-to-total-neutrophil (IT) ratio for suspected NBI in term and preterm neonates. All infants were retrospectively analyzed for NBI. Sensitivity, specificity, positive and negative predictive values, and 95% confidence intervals were calculated for IL-8, CRP, and IT ratio. Receiver-operating characteristic curves were analyzed to determine optimal thresholds. Between June 1997 and June 1998, IL-8 was measured 215 times in newborn infants with suspected NBI and the decision to start antibiotic therapy was based on increased IL-8 and/or CRP values. A cost-effectiveness analysis was performed and sensitivity, specificity, and receiver-operating characteristic curves were reevaluated. RESULTS: At the first suspicion of NBI, the combination of IL-8 >/= 53 pg/mL and/or CRP >10 mg/L detected culture-proven NBI with 96% sensitivity. The combined culture-proven and clinical NBI were detected with 93% sensitivity and 80% specificity. The use of IL-8 reduced unnecessary antibiotic therapy for suspected NBI by 73% and was cost-effective when compared with initiating antibiotic therapy based on clinical signs alone or based on clinical signs and an increased IT ratio and/or CRP. CONCLUSIONS: The combination of IL-8 and/or CRP is a reliable and early test for the diagnosis of NBI in newborn infants. Using the combination of IL-8 and/or CRP to restrict antibiotic therapy to truly infected infants reduces unnecessary antibiotic therapy and is cost-effective.

Anti-Bacterial Agents↗
PubMed1998

Comparison of lung volume measurements by antero-posterior chest X-ray and the SF6 washout technique in mechanically ventilated infants.

While anterior/posterior chest x-rays (CXR) are routinely performed to estimate lung volume (LV) and adjust ventilator settings, the precise measurement of LV requires additional sophistication. In 31 infants ventilated because of surfactant deficiency (n=23), bronchopulmonary dysplasia (n=7), or pulmonary hypoplasia (n=1) with either intermittent positive pressure (n=18) or high frequency oscillation (n=13) (gestational age 23-39 weeks (median 26 weeks); birthweight 550-2780 g (median 840 g); age at measurement 1-91 days (median 6 days); weight at study time (WST) 675-3000 g (median 938 g)), we investigated whether LV, as measured by the sulfur hexafluoride (SF6) washout technique, could by estimated from CXR by: 1) the sum (A+B) of the right (A) and left (B) lung fields areas; 2) the product (LxW) of the distances from the right apex to the right costophrenic angle (L) and between both costophrenic angles (W); 3) the diaphragm position relative to the posterior parts of the ribs (DP); and 4) the lung radiolucency (RL, grades 0-4). Correlations between A+B (r=0.44) or LxW (r=0.37) and LV were poor, but improved when A+B, LxW, and LV were normalized to WST: (A+B)/WST vs. LV/WST (r=0.74), and LxW/WST vs. LV/WST (r=0.67). DP (r=0.13) and RL (Spearman's rho=0.17) did not correlate with LV/WST. A multiple linear regression analysis led to the following best-fit equation: LV/WST=2.58 (A+B)/WST - 5.47 DP + 42.2 (r=0.83). We concluded that an estimate of LV from CXR lacked sufficient accuracy. DP and RL did not correlate with LV measured by SF6 washout.

Bronchopulmonary Dysplasia↗
PubMed1998

The effect of positive endexpiratory pressure, peak inspiratory pressure, and inspiratory time on functional residual capacity in mechanically ventilated preterm infants.

UNLABELLED: In mechanical ventilation of preterm infants, positive endexpiratory pressure (PEEP) is widely used to prevent alveolar collapse, maintain functional residual capacity (FRC) and improve oxygenation. Prolongation of inspiratory time (ti) and increase of peak inspiratory pressure (PIP) are also used for this purpose. We investigated the effect of variations of PEEP, PIP and ti on FRC in ten infants with hyaline membrane disease and onset of bronchopulmonary dysplasia (BPD, n = 7), pulmonary hypertension (n = 1), pulmonary hypoplasia (n = 1) or severe BPD (n = 1) (gestational age 24-39 weeks, median 26 weeks; birth weight 590-2960 g, 785 g; chronological age 7 84 days, 19 days; weight 689-4650 g, 1185 g). FRC, measured using the sulphur hexafluoride washout technique, was between 6.2 and 48.3 ml/kg (median 21.5 ml/kg). PEEP was changed stepwise 2-5 times in each patient (median 3) and mean airway pressure (MAP) was modified independently of PEEP by changing PIP 0 2 times (median 1) and ti 0(2 times (median 2). Changes of FRC correlated well with modifications of PEEP in each patient (r = 0.90, range 0.71 0.99). The slope factors of linear correlations had a median value of 2.94 ml/cm H20 per kg, which was significantly different from zero (P < 0.01) and significantly higher than the slope factors of linear correlations between FRC and MAP after modifications of PIP or ti (P < 0.01). The latter two were statistically not different from zero. The quotients deltaFRC/deltaMAP were significantly higher after adjustments of PEEP than after adjustments of PIP or ti (P < 0.01). The time lag between the change of PEEP and the stabilization of FRC on a new level ranged from 2 to 14 min (median 5). CONCLUSION: FRC is mainly determined by PEEP but not by PIP or ti. Stabilization of FRC after a change of PEEP can last up to 14 min. Its duration is unpredictable and has to be waited for when testing pulmonary function in ventilated preterm infants.

Functional Residual Capacity↗
PubMed1998

Neonatal hypocalcaemia associated with rotavirus diarrhoea.

UNLABELLED: We observed an association between rotavirus diarrhoea and hypocalcaemia in several patients and therefore started a prospective evaluation with measurement of calcium levels in all patients with rotavirus infection during a period of 8 months. We report on 54 infants with rotavirus gastro-enteritis. Serum concentrations of sodium, potassium, and total and ionized calcium were measured on admission. If hypocalcaemia was detected, total and ionized calcium were measured every day until recovery. Calcium was supplemented as calcium gluconate which was added to milk. Out of 54 newborns with rotavirus gastro-enteritis, 20 developed hypocalcaemia. All these newborns had severe diarrhoea. Seven infants were admitted because of convulsions, but EEG and ultrasonographic examination of the brain revealed no abnormalities. Once the infants' clinical condition and the consistency and frequency of the stool had improved, calcium concentrations increased and remained within the reference range without supplementation. CONCLUSION: Rotavirus gastro-enteritis seems to be a cause of neonatal hypocalcaemia.

Diarrhea, Infantile↗
PubMed1998

Prevention of necrotizing enterocolitis in extremely low birth weight infants by IgG feeding?

UNLABELLED: Oral immunoglobulin has been described as preventing necrotizing enterocolitis(NEC) in preterm infants. To prevent NEC in extremely low birth weight infants (ELBW), we have carried out oral IgG prophylaxis since April 1991. The efficacy of this prophylaxis was examined in a study comparing historical cohorts. ELBW infants delivered in the Department of Obstetrics and Gynaecology of the University of Ulm and treated until day 28 in the level III intensive care nursery, Division of Neonatology, University of Ulm were included. Cohort 1, born between 1.1.1988 and 31.3.1991, received no oral IgG and served as a control [n = 84, gestational age: median 26 weeks, range 24-34; birth weight: 811 g, 490-990], cohort 2, born between 1.4.1991 and 31.12.1995 [n= 137, gestational age: 26 weeks, 22-32; birth weight: 760 g, 362-995], received 6 x 100 mg/kg human IgG (Beriglobin) orally on days 1-28. NEC, stage 2a and higher according to the modified classification of Bell, was observed in 9 of 84 (10.7%) infants of cohort 1 and in 11 of 137 (8%) infants of cohort 2 until day 28. The difference did not reach statistical significance (P = 0.63 Fisher's exact test). CONCLUSION: In this historical cohort study, ELBW infants were not protected against NEC by oral IgG. The present published evidence does not allow recommendation of oral human IgG administration in preterm infants as a prophylactic measure against NEC.

Enterocolitis, Necrotizing↗
PubMed1998

Tension pneumopericardium in a preterm infant without mechanical ventilation: a rare cause of cardiac arrest.

A preterm infant with a gestational age of 32 weeks developed a tension pneumopericardium during the second day of life. The infant was treated with nasal continuous positive airway pressure and was not mechanically ventilated before pneumopericardium occurred. After emergency pericardiocentesis, two recurrences of pneumopericardium without clinical deterioration were diagnosed by X-ray during a 2-d observation period. A continuous pericardial drainage was positioned and was successfully removed on the seventh day of life after weaning from the ventilator. Tension pneumopericardium may occur even in non-ventilated newborns and should be considered as a rare but important differential diagnosis of cardiac arrest.

Disease-Free Survival↗
PubMed1998

Effect of the TI/TE ratio on mean intratracheal pressure in high-frequency oscillatory ventilation.

In high-frequency oscillatory ventilation (HFOV), an adequate mean airway pressure is crucial for successful ventilation and optimal gas exchange, but air trapping cannot be detected by the usual measurement at the y piece. Intratracheal pressures produced by the high-frequency oscillators HFV-Infantstar (IS), Babylog 8000 (BL), and the SensorMedics 3100A (SM) [the latter with either 30% (SM30) or 50% (SM50) inspiratory time] were investigated in four anesthetized tracheotomized female piglets that were 1 day old and weighed 1.6-1.9 kg (mean 1.76 kg). The endotracheal tube was repeatedly clamped while the piglets were ventilated with an oscillation frequency of 10 Hz, and the airway pressure distal of the clamp was recorded as a measure of average intrapulmonary pressure during oscillation. Clamping resulted in a significant decrease of mean airway pressure when the piglets were ventilated with SM30 (-0.86 cmH2O), BL (-0.66 cmH2O), and IS (-0.71 cmH2O), but airway pressure increased by a mean of 0.76 cmH2O with SM50. Intratracheal pressure, when measured by a catheter pressure transducer at various oscillation frequencies, was lower than at the y piece by 0.4-0.9 cmH2O (SM30), 0.3-3 cmH2O (BL), and 1-4.7 cmH2O (IS) but was 0.4-0.7 cmH2O higher with SM50. We conclude that the inspiratory-to-expiratory time (TI/TE) ratio influences the intratracheal and intrapulmonary pressures in HFOV and may sustain a mean pressure gradient between the y piece and the trachea. A TI/TE ratio < 1:1 may be useful to avoid air trapping when HFOV is used.

Animals↗
PubMed1998

Effects of mean airway pressure on lung volume during high-frequency oscillatory ventilation of preterm infants.

Measurement of mean lung volume (MLV) in high-frequency oscillatory ventilation (HFO) may be useful for optimizing the high lung volume strategy, but has not been available until now. We have measured MLV by means of the sulfur hexafluoride (SF6) washout method in 13 premature infants ventilated with HFO because of respiratory distress syndrome (gestational age, 23 to 31 wk [median, 25 + 6/7 wk]; birthweight, 630 to 1,140 g [790 g]; age at measurement, 2 to 10 d [4 d]; weight, 675 to 1,250 g [850 g]). To evaluate the relationship between MLV and mean airway pressure (MAP), the latter was systematically varied between the measurements. With clinically selected MAP, MLV was between 23.3 and 41.9 ml/kg (median, 33.5 ml/kg) and was strongly dependent on MAP in each patient; linear regression analyses resulted in slope factors between 1.0 and 6.9 ml/cm H2O/kg (median, 2.83 ml/cm H2O/kg), with correlation coefficients between 0.77 and 0.99 (median, 0.94). Stabilization of MLV after modification of MAP took 2 to 25 min (median, 9 min). We conclude that the selection of MAP on a clinical basis leads to a wide range of different MLVs. Despite the strong dependence of MLV on MAP, the prediction of MLV solely based on MAP was impossible because of large patient to patient variability of linear regressions. Alveolar recruitment and derecruitment may take up to 25 min after MAP changes.

Airway Resistance↗
PubMed1998

Comparison of pulmonary inflammatory mediators in preterm infants treated with intermittent positive pressure ventilation or high frequency oscillatory ventilation.

Ventilated preterm infants prone to the development of bronchopulmonary dysplasia have been shown to have increased inflammatory mediators in their tracheal aspirates. High frequency oscillatory ventilation (HFOV) is thought to be less traumatic than intermittent positive pressure ventilation (IPPV) in premature infants with surfactant deficiency, and therefore may reduce the inflammatory response in tracheobronchial aspirates. We randomized 76 premature infants requiring mechanical ventilation (birth weight 420-1830 g, median 840 g, gestational age 23 3/7 to 29 2/7 wk, median 26 4/7 to receive either an IPPV with a high rate (60-80/min) and low peak pressures, or an HFOV aiming at an optimization of lung volume, within 1 h of intubation. Tracheal aspirates were systematically collected during the first 10 d of life and analyzed for albumin, IL-8, leukotriene B4 (LTB4), and the secretory component (SC) for IgA as a reference protein. Bacterially colonized samples were excluded. On the treatment d 1, 3, 5, 7, and 10, the resulting median values of albumin (milligrams/mg of SC) were 28, 23, 24, 18, and 10, in IPPV-ventilated infants, and 33, 28, 18, 25, and 39 in HFOV-ventilated infants, respectively. Median IL-8 values (nanograms/mg of SC) were 671, 736, 705, 1362, and 1879 (IPPV) and 874, 1713, 1029, 1426, and 1823 (HFOV), respectively, and median LTB4 values (nanograms/mg of SC) were 26, 13, 27, 22, and 11 (IPPV) and 15, 12, 7, 12, and 16 (HFOV), respectively. Values were similar in IPPV- and HFOV-ventilated infants, and no significant differences were noted. We conclude that HFOV, when compared with a high rate low pressure IPPV, does not reduce concentrations of albumin, IL-8, and LTB4 in tracheal aspirates of preterm infants requiring mechanical ventilation.

Albumins↗