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Martin Keszler

Publications and source records attributed to Martin Keszler.

12 recordsLinked to original sources
PubMed2006

Volume-targeted ventilation.

Recognition that volume, not pressure, is the key factor in ventilator-induced lung injury and the association of hypocarbia and brain injury dictate the need to better control delivered tidal volume. Volume-controlled ventilation, though much improved, still suffers from loss of volume due to endotracheal tube leak and gas compression in the circuit. Recent microprocessor-based modifications of pressure-limited, time-cycled ventilators combine advantages of pressure-limited ventilation with the ability to deliver a more consistent tidal volume. Each of the modes has advantages and disadvantages, with limited data available to judge their effectiveness. The Volume Guarantee mode, studied most thoroughly, provides automatic weaning of peak pressure in response to improving lung compliance and respiratory effort. More consistent tidal volume, fewer excessively large breaths, lower peak pressure, less hypocarbia and lower levels of inflammatory cytokines have been documented. It remains to be seen if these short-term benefits translate into shorter duration of ventilation or reduced incidence of chronic lung disease.

Humans↗
PubMed2005

Volume-targeted ventilation.

Recognition that volume, not pressure, is the key factor in ventilator-induced lung injury and awareness of the association of hypocarbia and brain injury foster the desire to better control delivered tidal volume. Recently, microprocessor-based modifications of pressure-limited, time-cycled ventilators were developed to combine advantages of pressure-limited ventilation with the ability to deliver a more consistent tidal volume. Each of the modes has advantages and disadvantages, with limited clinical data available to judge their effectiveness. The Volume Guarantee mode has been studied most thoroughly and is the only one that provides automatic weaning of peak pressure in response to improving lung compliance and patient respiratory effort. More consistent tidal volume, fewer excessively large breaths, lower peak pressure, less hypocarbia and lower levels of inflammatory cytokines have been documented. It remains to be seen if these short-term benefits will translate into shorter duration of ventilation or reduced incidence of chronic lung disease.

Humans↗
PubMed2005

Effect of volume guarantee combined with assist/control vs synchronized intermittent mandatory ventilation.

OBJECTIVE: To compare the effect of combining assist/control with volume-guarantee (AC+VG) vs synchronized intermittent mandatory ventilation with VG (SIMV+VG) on tidal volume (V(T)), peak inspiratory pressure (PIP), mean airway pressure (MAP), respiratory rate, heart rate, oxygen saturation (SpO(2)), and minute volume (MV) in preterm infants. STUDY DESIGN: A total of 12 infants were randomized to receive AC+VG, followed by SIMV+VG, or the opposite sequence for four alternating 2-hour periods. RESULTS: Airway pressure of machine breaths was higher during SIMV. MV and V(Te) were similar, but more variable during synchronized intermittent mandatory ventilation. The V(Te) of unsupported breaths during SIMV was lower than machine breaths of SIMV and AC. There was more tachycardia and tachypnea with a lower and more variable SpO(2) during SIMV. CONCLUSIONS: SIMV+VG is associated with higher work of breathing indicated by tachycardia, tachypnea and lower SpO(2) compared to AC+VG. VG appears to be more effective when combined with AC than with SIMV.

Continuous Positive Airway Pressure↗
PubMed2004

Volume guarantee: stability of tidal volume and incidence of hypocarbia.

Excessive tidal volume (V(T)) can lead to lung injury, hypocarbia, and neurologic damage. Volume guarantee (VG) uses exhaled V(T) as the control variable to reduce the risk of volutrauma and more closely control PaCO(2). Our objective was to test the hypothesis that VG combined with assist/control (A/C) will maintain PaCO(2) and V(T) within target range more consistently than assist/control alone during the first 72 hr of life in ventilated preterm infants. Eligible infants were randomly assigned to A/C + VG or A/C alone. Data were recorded directly from the pressure and volume module of the Draeger Babylog 8000+ ventilator. Arterial blood gases were obtained every 2-6 hr, as clinically indicated. In A/C, inspiratory pressure was adjusted to achieve a V(T) of 4-6 ml/kg. In VG, the target V(T) was 5 ml/kg. Subsequent adjustments were made by the clinical team in response to arterial blood gas measurements (ABG). Proportion of breaths and PaCO(2) values outside the target range were compared by chi(2), and continuous variables by t-test. There were no differences in demographic or baseline ventilator variables between the 18 infants in the two groups. For 1,805/11,950 breaths (15.1%), V(T) was > target with A/C + VG, vs. 2,503/9,853 (25.4%) with A/C (P < 0.001). V(T) was < target for 21.7% of breaths with A/C + VG, vs. 35.7% with A/C (P < 0.001). Twenty percent of PaCO(2) values were < target, with A/C + VG vs. 36.3% with A/C, P < 0.05. The proportion of PaCO(2) values > target was similar in the two groups. Oxygenation and mean pH were not different. No complications related to mechanical ventilation were observed. In conclusion, VG significantly reduced hypocarbia and excessively large V(T). This suggests the potential to reduce pulmonary and neurologic complications of mechanical ventilation. Larger studies are needed to establish safety and demonstrate such benefits.

Carbon Dioxide↗
PubMed2003

Low-dose nitric oxide therapy for persistent pulmonary hypertension: 1-year follow-up.

BACKGROUND: Although inhaled nitric oxide has been shown to reduce the use of extracorporeal membrane oxygenation, there is limited data on its effect on long-term outcomes. OBJECTIVE: The purpose of our study is to report on the 1 year outcome of neonates treated with inhaled nitric oxide compared to a group of neonates who did not receive nitric oxide. METHODS: We have previously reported on the in-hospital outcomes of 248 neonates who were >34 weeks' gestational age and were randomized to receive low-dose inhaled nitric oxide or placebo. Extracorporeal membrane oxygenation was used in 78 (64%) neonates in the control group and in 48 (38%) neonates in the inhaled nitric oxide group (p=0.001). We now report on the outcome of neonates followed to 1 year of age. RESULTS: Of the 248 neonates twenty-four (10%) died before 1 year of age. There was no difference in mortality between the two groups (11% in the control group and 9% in the inhaled nitric oxide group). Of the 224 surviving infants, we were able to contact the parents or guardians of 201 (90%) children. There were no intergroup differences in the numbers of patients reported as requiring medications for pulmonary disease (14% in the control group and 14% in the inhaled nitric oxide group) or the need for supplemental oxygen (1% in the control group and 0% in the inhaled nitric oxide group). The number of neonates reported to have an abnormal neurological examination or developmental delay was also similar in both groups (14% in the control group and 19% in the inhaled nitric oxide group). CONCLUSIONS: The use of low-dose inhaled nitric oxide reduces the use of extracorporeal membrane oxygenation without increasing the incidence of adverse outcomes to 1 year of age.

Administration, Inhalation↗
PubMed2003

Interaction between surfactant and ventilatory support in newborns with primary surfactant deficiency.

The interaction between exogenous surfactant and various modes of ventilatory support in terms of timing, quality and quantity can influence both short- and long-term outcomes of immature infants. Alterations to the pulmonary surfactant system can occur with all forms of mechanical ventilation. Experimental data suggest possible interaction between ventilatory support and exogenous surfactant even during the first breaths in the delivery room. The adverse effect on surfactant function at this time can increase the need for and duration of ventilatory support. The logical approach to ventilatory support is to be minimally aggressive with optimal recruitment of the lungs to avoid ventilator-induced lung injury. Nasal continuous positive airway pressure (CPAP) in combination with early prophylactic surfactant administration may be an effective and less damaging method capable of reducing the need of artificial ventilation, but its benefit has not been proven in extremely preterm infants less than 28 weeks' gestation. Because of unproven efficacy of nasal CPAP in extremely premature infants, the population most at risk for adverse pulmonary and neurologic outcome, this paper focuses on the comparison of conventional and high-frequency oscillatory ventilation (HFOV) with respect to alteration of surfactant function, and short- and long-term outcomes, in both human and experimental trials. Though the two most recent large clinical trials provide reassurance with respect to the safety of first-intention high-frequency ventilation, the reduction in the risk of chronic lung disease appears to be only modest or absent. Recent laboratory investigations suggest that the key element of HFOV, namely optimization of volume, can, under some circumstances, be replicated with low tidal volume conventional ventilation and high positive end-expiratory pressure. Recent introduction of patient-triggered volume-targeted conventional ventilation into clinical practice offers the promise of a practical means of providing gentle conventional ventilation capable of minimizing ventilator-induced lung injury. Ultimately, well-designed comparative clinical trials with long-term outcomes are essential to accurately quantify risks and benefits of any new approach to mechanical ventilation. Without such data, these experimental results should not be extrapolated into clinical practice, because of the multifactorial pathophysiology of the development of chronic pulmonary disease in extremely premature infants and the risk of unanticipated adverse effects.

Bronchopulmonary Dysplasia↗
PubMed2002

Early versus delayed surfactant administration in extremely premature neonates with respiratory distress syndrome ventilated by high-frequency oscillatory ventilation.

OBJECTIVE: To determine whether early surfactant administration is superior to selective delayed treatment in terms of improving survival and/or reducing chronic lung disease in extremely premature neonates with respiratory distress syndrome (RDS) treated by high-frequency oscillatory ventilation (HFOV). DESIGN: Prospective randomized clinical trial. SETTING: Tertiary neonatal intensive care unit (NICU) in the Perinatology Center of Prague. PATIENTS: Forty-three extremely premature infants who needed artificial ventilation within 3 h after delivery. INTERVENTIONS: Patients were randomly assigned to either early ( n=21) or delayed (n=22) administration of surfactant. All were ventilated by HFOV as the primary mode of ventilation using the high volume strategy aimed at optimizing lung volume. Curosurf at a dose of 100 mg/kg was given as a single bolus via the endotracheal tube within 1 min immediately after intubation in the early group (EARL), or during HFOV only when defined criteria were reached in the delayed (DEL) group. MEASUREMENTS AND RESULTS: No differences were noted in demographic data between the two groups. Fewer infants randomized to the EARL group required oxygen use or died at 36 weeks (combined outcome 29% vs 64%, p=0.021), and there was a lower incidence of any intraventricular hemorrhage in this group (43 vs 82%, p=0.008). CONCLUSIONS: When compared to delayed dosing, early administration of surfactant followed by HFOV facilitates and accelerates respiratory stabilization during the acute phase of severe RDS, may reduce the incidence of chronic lung disease or death and may positively influence the incidence of severe intracranial pathology in extremely premature infants with primary surfactant insufficiency.

Chronic Disease↗
PubMed2002

A multicenter, randomized, controlled trial comparing Surfaxin (Lucinactant) lavage with standard care for treatment of meconium aspiration syndrome.

OBJECTIVE: Infants with meconium aspiration syndrome (MAS) have marked surfactant dysfunction. Airways and alveoli of affected neonates contain meconium, inflammatory cells, inflammatory mediators, edema fluid, protein, and other debris. The objective of this study was to compare treatment with bronchoalveolar lavage using dilute Surfaxin with standard therapy in a population of newborn infants with MAS. METHODS: Inclusion criteria were 1) gestational age > or =35 weeks, 2) enrollment within 72 hours of birth, 3) diagnosis of MAS, 4) need for mechanical ventilation, and 5) an oxygenation index > or =8 and < or =25. Subjects were randomized to either lavage with Surfaxin or standard care (2:1 proportion). In lavaged infants, a volume of 8 mL/kg dilute Surfaxin (2.5 mg/mL) was instilled into each lung over approximately 20 seconds followed by suctioning after 5 ventilator breaths. The procedure was repeated twice. The third and final lavage was with a more concentrated solution (10 mg/mL) of Surfaxin. RESULTS: Twenty-two infants were enrolled (15 Surfaxin and 7 control). Demographic characteristics were similar. There were trends (not significant) for Surfaxin-lavaged infants to be weaned from mechanical ventilation earlier (mean of 6.3 vs 9.9 days, respectively), as well as to have a more rapid decline in their oxygenation indexes compared with control infants, the latter difference persisting for the 96-hour-long study period. The therapy was safe and generally well tolerated by the infants. CONCLUSIONS: Dilute Surfaxin lavage seems to be a safe and potentially effective therapy in the treatment of MAS. Data from this investigation support future prospective, controlled clinical trials of bronchoalveolar lavage with Surfaxin in neonates with MAS.

Bronchoalveolar Lavage↗
PubMedDate not supplied

Triplet morbidity and mortality in a large case series.

OBJECTIVE: A significant increase in the triplet birth rate has occurred recently. This rise is of concern, as these infants are historically reported to be at risk of adverse outcome. Thus, we examined the outcome of triplet births in a large contemporary case series. STUDY DESIGN: Since 1993, detailed clinical data have been collected on all patients admitted to our Neonatal Intensive Care Unit. We retrospectively analyzed this database to examine triplet outcome. RESULTS: A total of 51 consecutive sets of triplets were born over a 9-year period. The mean birth weight for triplets was 1789+/-505 g, mean gestational age was 32.6+/-2.7 weeks, with discordancy present in 17.6% of neonates. Complications of prematurity were infrequent. Triplet survival to discharge was 96%. CONCLUSIONS: This large contemporary case series of triplets demonstrates excellent survival with low associated morbidity. These data suggest that there may no longer be medical justification for offering selective fetal reduction to parents with triplet pregnancies.

Adult↗