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Biomedical subjects

F L Mannino

Publications and source records attributed to F L Mannino.

At least 19 recordsLinked to original sources
PubMed1995

Improved oxygenation during synchronized intermittent mandatory ventilation in neonates with respiratory distress syndrome: a randomized, crossover study.

In a randomized, crossover study, we compared arterial partial pressure of oxygen and of carbon dioxide between consecutive periods of conventional and synchronized intermittent mandatory ventilation (SIMV). We studied spontaneously breathing infants with an endotracheal tube in place. The infants were < 12 hours of age, had a diagnosis of respiratory distress syndrome, and had an arterial/alveolar oxygen ratio of < 0.25. The infants had a mean birth weight of 1077 gm and gestational age of 28 weeks. The mean rate of asynchrony on intermittent mandatory ventilation (IMV) was 52% (range, 36% to 76%), and on SIMV was < 1%. Infants were randomly assigned to IMV or SIMV as their initial ventilator mode and underwent ventilation for four 15-minute periods, and crossed over to the alternate mode after each period. Ventilator settings and the fraction of inspired oxygen were not changed between modes. At the end of each period, arterial blood gas measurements were obtained; 26 paired comparisons were made between modes. The mean arterial partial pressure of oxygen was significantly higher during SIMV than during IMV (mean, 61.5 vs 53.3 mmHg; p < 0.01). The mean arterial partial pressure of carbon dioxide was slightly lower during SIMV than during IMV (mean, 42.7 vs 41.3 mm Hg; p < 0.05). The improvement in oxygenation demonstrated with SIMV may allow a reduction in ventilator pressure or oxygen exposure in this group of infants, who are at risk of having complications of ventilation.

Carbon Dioxide↗
PubMed1994

Increased and more consistent tidal volumes during synchronized intermittent mandatory ventilation in newborn infants.

We compared expiratory tidal and minute ventilation during conventional and synchronized intermittent mandatory ventilation (IMV and SIMV) in 30 infants with respiratory failure. Identical ventilator settings were used during each mode in each infant. Tidal volumes of ventilator breaths were smaller during IMV than during SIMV (6.2 +/- 1.8 versus 7.4 +/- 1.9 ml/kg; p < 0.01). The coefficient of variation of tidal volumes was higher during IMV than SIMV for both ventilator (25 +/- 12% versus 15 +/- 8%) and spontaneous breaths (39 +/- 15% versus 24 +/- 10%, p < 0.001). Minute ventilation, however, was the same during both modes. During IMV, one infant breathed synchronously and two were phase-locked in asynchrony with the ventilator. The infants with a mixed interaction on IMV (27 of 30) had tidal volumes that depended on the phase of spontaneous breathing at the time of onset of each ventilator breath. Tidal volumes of IMV breaths that began during the first half of spontaneous expiration had the smallest tidal volumes (5.4 +/- 1.8 ml/kg, p < 0.01), followed by those that began during the last half of inspiration (6.4 +/- 1.8 ml/kg, p < 0.01). Thus, the synchrony produced by SIMV allowed the ventilator to deliver larger and more consistent tidal volumes than during IMV.

Humans↗
PubMed1992

Intrauterine death in multiple gestation.

Intrauterine death of one fetus in a multiple gestation is associated with significant morbidity and mortality in the surviving infant. This study is a retrospective review of 38 twin and 3 triplet gestations involving the intrauterine death of at least one fetus. The obstetrical history, placental pathology, autopsy findings, and neonatal history of the surviving infant are reviewed. Three cases involved the recent stillbirth of both twins, the remaining cases involved a surviving infant. In one case, neonatal death of a surviving twin occurred on day 19. In two sets of triplets, two stillbirths occurred, in the third case two infants were liveborn. The incidence of preterm delivery was 34%, which decreased to 18% if fetal cotwin death had occurred before 20 weeks gestation. Cesarean section was the method of delivery in 16 cases. There was an excess of velamentous cord insertions, which was most pronounced in the stillborn twin. Monochorionic placentation was found in 72%, also an excess. Neurological damage was known to have occurred in 19 of the 39 surviving infants. Fifteen of these 19 (79%) were associated with monochorionic placentation. The neurologically damaged twin infants, when compared to the normal infants, had the cotwin die later in gestation (31 vs 16.5 weeks), had a shorter duration between the death of the cotwin and delivery (2.5 vs 21 weeks), and delivered earlier in gestation (36.5 vs 39.5 weeks). The probable cause of neurological damage, in our opinion, was either exsanguination into the dead twin fetus, or disseminated intravascular coagulation which occurred in at least 13 cases. The incidence of antepartum death in a multiple gestation, and the potential for neurological damage is probably higher than previously thought. A review of the literature is presented and the clinical implications of this phenomenon are discussed.

Brain Damage, Chronic↗
PubMed1989

One-lung high-frequency ventilation in the management of an acquired neonatal pulmonary cyst.

Pulmonary cystic lesions presenting in the neonatal period can be congenital in origin, such as cystic adenomatoid malformation and congenital lobar emphysema, or they can be acquired. With recent advances in the support of premature infants with respiratory distress syndrome (RDS), acquired cystic lesions such as pulmonary interstitial emphysema (PIE), lobar emphysema, and parenchymal cysts have become more common. Several treatments have been proposed for these acquired lesions. We report what we believe to be the first case in which unilateral high-frequency ventilation (HFV) combined with low-rate intermittent mandatory ventilation (IMV) has been used to successfully manage an acquired lung cyst in a newborn.

Cysts↗
PubMed1989

[Spontaneous intestinal perforation in newborn infants. A form of necrotizing enterocolitis].

The present study comprised twelve premature infants with "spontaneous" gastrointestinal perforations studied retrospectively during a period of three years. This problem was found to be more frequent in extremely premature babies affected with respiratory distress syndrome and patent ductus arteriosus and accompanied with very high mortality. A clinical-pathological correlation was done with the intestinal biopsy or postmortem studies and according to these findings, it is suggested that "spontaneous" intestinal perforations probably represent a form of necrotizing enterocolitis.

Enterocolitis, Pseudomembranous↗
PubMed1988

High-frequency oscillatory ventilation combined with intermittent mandatory ventilation in critically ill neonates: 3 years of experience.

A heterogeneous group of 45 neonates with severe pulmonary disease and inadequate gas exchange on conventional intermittent mandatory ventilation (IMV) was treated with a high-frequency oscillator combined with an IMV (HFO-IMV) system (Emerson Airway Vibrator connected to a BABYBird 1 ventilator). The mean gestational age was 33 weeks (25.5-43) and mean birth weight 2.02 kg (0.66-4.24). Primary diagnoses included respiratory distress syndrome (RDS; 23), pneumonia (12), persistent fetal circulation (PFC; 6), diaphragmatic hernia/hypoplastic lungs (4). The IMV rate was reduced from 78 to 29 BPM (P less than or equal to 0.0005), while maintaining lower partial pressure of carbon dioxide (PaCO2) (P less than 0.005) and higher partial pressure of oxygen (PaO2) (P less than or equal to 0.0025). Active air leaks were present in 20 infants and these infants responded most favourably to HFO-IMV. HFO-IMV failed to improve ventilation in neonates with diaphragmatic hernia/hypoplastic lungs. Complications during HFO-IMV were increased pulmonary secretions (11), worsening or recurrence of pre-existing air leaks (11), or occurrence of new air leaks (10). In 4 patients death was related to major air leak complications. Twenty-four infants died, 18 of them of a respiratory cause. Twenty-one infants finally survived. We assembled a well-tolerated system to provide HFO-IMV and to successfully ventilate neonates with severe respiratory disease, who failed to respond to conventional IMV. Initiation of HFO-IMV earlier in the course of the disease in this type of infant may improve survival.

Female↗
PubMed1987

Effects of infant ventilator design on spontaneous breathing.

Study of the mechanical work of spontaneous breaths taken by eight infants attached to infant ventilators. Work was estimated from the volume displacement and pressure fluctuations of breathing during steady state mechanical ventilator conditions (i.e., stable peak or PEEP pressures). A broad difference existed between manufacturers of infant ventilators; a dramatic reduction was seen in work when attached to a demand as compared to a continuous flow device. Additionally, some change in work occurred, depending on the phase of the IMV cycle in which spontaneous breath was taken. Dynamic testing of ventilators can reveal differences in function.

Equipment Design↗
PubMed1986

A system for high-frequency oscillatory ventilation and intermittent mandatory ventilation in neonates.

We combined high-frequency oscillatory ventilation and intermittent mandatory ventilation, using a system composed of an Emerson airway vibrator, a Babybird 1 ventilator, and rate/pressure monitors. The Emerson device, a modified air compressor with rate controller, oscillated a small volume of gas at the airway. This device was coupled to the bird unit through a circuit of our design. Humidified fresh gas and pressure-relief valves were provided by the bird ventilator, and mean airway pressure was adjusted by its expiratory-limb venturi device or by the end-expiratory pressure control. The volume of gas delivered by the oscillator to various sites was measured with a plethysmograph tuned to high frequencies. At frequencies of 20 to 30 Hz, a 27-ml volume from the oscillator decreased to between 7 and 14 ml at the proximal airway, and to between 0.1 and 2.3 ml at the distal tip of the endotracheal tube. The magnitude of this decrease depended on the size of the endotracheal tube, the circuit resistance of the ventilator, oscillation frequency, and the position of the oscillator's expansion-chamber valve. We have used this system for over 3 yr to ventilate sick neonates safely and effectively.

Equipment Design↗
PubMed1985

Moisture-conserving efficiency of condenser humidifiers.

The moisture-conserving efficiency of commercially available condenser humidifiers (small, disposable, airway humidifiers) was studied. A comprehensive comparison of all currently available condenser humidifiers utilising a laboratory system which simulated a breathing, intubated patient in temperature, humidity, dead space, and respiratory pattern characteristics was undertaken. The percentage of moisture conserved, or efficiency, of the humidifiers was calculated gravimetrically from the water loss of the testing system with and without the condenser humidifiers. The Portex Humid-Vent and Trach-Vent, Siemens Servo 150 and the Terumo Brethaia were evaluated. The data revealed an inverse correlation between efficiency and tidal volume. The most efficient were the Portex Humid-Vent at low tidal volumes and Siemens Servo 150 at the mid and high tidal volumes. To achieve a minimum inspired water content of 33 mg H2O/litre gas, a 79% condenser humidifier efficiency is necessary. None of these units met this requirement; however, they may be appropriate for limited clinical application.

Anesthesia, Inhalation↗
PubMed1984

Combined high-frequency oscillatory ventilation and intermittent mandatory ventilation in critically ill neonates.

Combined high-frequency oscillatory ventilation (HFOV) and intermittent mandatory ventilation (IMV) was used in 12 neonates with inadequate gas exchange with conventional IMV. Diagnoses included diaphragmatic hernia with hypoplastic lungs, pneumonia, persistent fetal circulation, and severe respiratory distress syndrome. In most patients there was severe air leak. Within 10 hours of beginning HFOV-IMV the mean arterial PCO2 fell from 60 +/- 5 (means +/- SEM) to 38 +/- 2 mm Hg (P less than 0.01) and the mean IMV rate was reduced from 96 +/- 8 to 17 +/- 4 breaths per minute (P less than 0.001). The mean arterial-alveolar oxygen tension ratio rose from 0.05 +/- 0.01 to 0.09 +/- 0.01 (P less than 0.005). Mean airway pressure in the trachea was reduced from 16 +/- 2 to 10 +/- 3 cm H2O (P less than 0.05). Four patients died, three of whom had diaphragmatic hernias with hypoplastic lungs. Five of the eight survivors had mild bronchopulmonary dysplasia requiring supplemental oxygen. These studies demonstrate that in some neonates with respiratory failure who fail to respond to conventional IMV, combined HFOV-IMV can be successful.

Bronchopulmonary Dysplasia↗
PubMed1984

Airway pressure measurement during high frequency oscillatory ventilation.

We developed a method to measure accurately pressures at the airway opening (Pao) and in the trachea (Ptr) in neonates during high frequency oscillatory ventilation (HFOV) from 15-30 Hz. All component parts of the pressure-measuring system were tested as a unit against a reference transducer in a closed chamber in which sinusoidal pressure waves could be generated. The resulting waveforms were displayed on an oscilloscope and measured. Ptr was measured through the intramural lumen of a Hi-Lo jet tracheal tube (National Catheter Co., Argyle, NY) opening 1 cm above the distal tip. Pressure readings from uncorrected waveforms indicated a discrepancy between measured and actual pressures, as high as 100% at frequencies of 100 Hz. When the resonance of the system was damped with a CorrecTORR (Norton Health Care Products, Akron, OH), the ratio of test to reference transducer output was flat +/- 5% from 0-160 Hz for the Pao system and flat +/- 4% from 0-100 Hz for the Ptr system. Ptr system accuracy was verified in an excised rabbit lung and the systems were used clinically in neonatal HFOV. We conclude that Pao and Ptr can be measured accurately during HFOV by this method.

Critical Care↗
PubMed1983

Stroke in neonates.

Five neonates with large cerebral infarctions of arterial origin are presented. Four had severe focal seizures on the first day of life. The fifth, a premature infant, was asymptomatic. The diagnoses were made by computed tomography (CT) scans between 5 and 12 days of life; CT scans obtained in the first few days of life were normal. In the fifth infant, the infarct was hemorrhagic and was also noted by cranial ultrasound. Three of the infants had a history of trauma to the head or neck during labor and birth. Only one was severely asphyxiated at birth. Two apparently are doing well at 1 year of age. Cerebral infarcts of arterial origin in neonates probably have been missed in living patients in the past, but now are recognized in the newborn period by properly timed CT examination.

Cerebral Hemorrhage↗
PubMed1982

Pulmonary gas exchange during high-frequency ventilation.

Gas exchange was investigated in normal anesthetized dogs during high-frequency, low-tidal volume ventilation (HFV) using the multiple inert gas elimination method. The pattern of inert gas elimination was initially normal during conventional mechanical ventilation. During HFV there was an increase in the difference between the excretion values of acetone and its less soluble neighboring gases, enflurane and ether, but elimination was independent of molecular weight. This pattern was consistent with a major degree of parallel ventilation-perfusion inequality with 49.4 +/- 1.7% of alveolar ventilation being distributed to lung units with VA/Q ratios greater than 20. Additional experiments, however, showed insufficient change in pulmonary blood flow distribution during HFV to account for these apparently poorly perfused lung units. Instead, it was found that the flux from the lung of the most soluble gas, acetone, per unit concentration difference along the airways was approximately twice that for other gases. Experiments using a simple airway model suggested that this enhanced transport of high-solubility gases during HFV is dependent on the wet luminal surface of conducting airways. A reciprocating exchange of gas between the lumen and airway lining layer is proposed as the most likely explanation for these results.

Anesthesia↗