Biomedical subjects

R B Hirschl

Publications and source records attributed to R B Hirschl.

At least 55 records · Page 3Linked to original sources

PubMed1998

Partial liquid ventilation decreases albumin leak in the setting of acute lung injury.

PURPOSE: This study evaluated the ability of partial liquid ventilation (PLV, gas ventilation of the perfluorocarbon-filled lungs) to reduce the amount of lung albumin leak present in the setting of acute lung injury. MATERIALS AND METHODS: An experimental controlled, randomized design was used. All studies were performed in the liquid ventilation laboratories at the University of Michigan Medical Center. Twenty-five Sprague-Dawley male rats 500+/-50 g were divided into five experimental groups: (1) CVF only (n=5), animals were cobra venom factor (CVF) lung injured; (2) PLV-CVF (n=5) animals received perflubron and PLV before CVF lung injury; (3) CVF-PLV (n=5) animals received PLV after CVF lung injury; (4) PLV only (n=5) animals underwent partial liquid ventilation without lung injury; and (5) Gas only (n=5) animals underwent gas ventilation without lung injury. In all groups iodinated bovine serum albumin (125I-BSA) was delivered by intravenous injection along with CVF or a saline placebo. RESULTS: When the CVF animals were compared with all other groups, a decrease in albumin leak was observed for all groups when compared with the CVF only controls (P < .001 by ANOVA; CVF only=1.22+/-0.12 versus PLV-CVF=0.46+/-0.08, P < .001; CVF-PLV=0.70+/-0.25, P < .001; PLV only=0.22+/-0.01, P < .001; Gas only=0.17+/-0.02, P < .001). CONCLUSIONS: These data suggest that intratracheal instillation of perfluorocarbon before or after induction of lung injury results in a reduction in pulmonary albumin leak.

Analysis of Variance↗

PubMed1998

An approach to the treatment of severe adult respiratory failure.

OBJECTIVES: The purpose of this article is to evaluate outcome in adult patients with severe respiratory failure managed with an approach using (1) limitation of end inspiratory pressure, (2) inverse ratio ventilation, (3) titration of PEEP by SvO2, (4) intermittent prone positioning, (5) limitation of FiO2, (6) diuresis, (7) transfusion, and (8) extracorporeal life support (ECLS) if patients failed to respond. PATIENTS AND METHODS: This study was designed as a retrospective review in the intensive care unit of a tertiary referral hospital. One-hundred forty-one consecutive patients with hypoxic (n = 135) or hypercarbic (n = 6) respiratory failure referred for consideration of ECLS between 1990 and 1996. Overall, initial PaO2/FiO2 (P/F) ratio was 75+/-5 (median = 66). RESULTS: Lung recovery occurred in 67% of patients and 62% survived. Forty-one patients improved without ECLS (83% survived); 100 did not and were supported with ECLS (54% survived). Survival was greater in patients cannulated within 12 hours of arrival (59%) compared with those cannulated after 12 hours (40%, P < .05). Multiple logistic regression identified age, duration of mechanical ventilation before transfer, four or more dysfunctional organs, and the requirement for ECLS as independent predictors of mortality. CONCLUSIONS: An approach that emphasizes lung protection and early implementation of extracorporeal life support is associated with high rates of survival in patients with severe respiratory failure.

Adolescent↗

PubMed1998

Partial liquid ventilation in adult patients with ARDS: a multicenter phase I-II trial. Adult PLV Study Group.

OBJECTIVE: To evaluate the safety and efficacy of partial liquid ventilation (PLV) in adult patients with the acute respiratory distress syndrome (ARDS). SUMMARY BACKGROUND DATA: Previous studies have evaluated gas exchange and the safety of PLV in adult patients with severe respiratory failure whose gas exchange was partially provided by extracorporeal life support (ECLS). This is the first experience with adult patients who were not on ECLS. METHODS: Intratracheal perflubron in a total dose of 30.1 +/- 7.1 ml/kg was administered over a period of 45 +/- 9 hours to nine adult patients with mean age = 49 +/- 4 years and mean PaO2/FiO2 ratio = 128 +/- 7 as part of a prospective, multicenter, phase I-II noncontrolled trial. RESULTS: Significant decreases in mean (A-a)DO2 (baseline = 430 +/- 47, 48 hour = 229 +/- 17, p = 0.0127 by ANOVA) and FiO2 (baseline = 0.82 +/- 0.08, 48 hour = 0.54 +/- 0.06, p = 0.025), along with an increase in mean SvO2 (baseline = 75 +/- 3, 48 hour = 85 +/- 2, p = 0.018 by ANOVA) were observed. No significant changes in pulmonary compliance or hemodynamic variables were noted. Seven of the nine patients in this study survived beyond 28 days after initiation of partial liquid ventilation whereas 5 patients survived to discharge. Three adverse events [hypoxia (2) and hyperbilirubinemia (1)] were determined to be severe in nature. CONCLUSIONS: These data suggest that PLV may be performed safely with few related severe adverse effects. Improvement in gas exchange was observed in this series of adult patients over the 48 hours after initiation of PLV.

Adult↗

PubMed1998

Effects of partial liquid ventilation on lung injury in a model of acute respiratory failure: a histologic and morphometric analysis.

OBJECTIVE: To compare the histopathologic changes observed in a sheep model of oleic acid-induced acute respiratory failure during partial liquid ventilation with perflubron with gas ventilation. DESIGN: Randomized, controlled study. SETTING: Animal laboratory and pathology laboratories of a university hospital. SUBJECTS: Fourteen healthy adult sheep, weighing 64.9 +/- 6.4 kg. INTERVENTIONS: Lung injury was induced with oleic acid (0.15 mL/kg). A tracheostomy tube was inserted, along with systemic and pulmonary artery monitoring catheters. Animals were randomized to undergo either partial liquid ventilation (n = 7) or gas ventilation (n = 7). Animals underwent euthanasia at the end of the 90-min study period, after which the endotracheal tube was clamped with the lungs in expiratory hold at a positive end-expiratory pressure of 5 cm H2O. En bloc excision of the heart and lungs was performed by thoracotomy. Perfusion of the isolated lung vasculature with 2.5% paraformaldehyde and 0.25% glutaraldehyde in a 0.1-M phosphate buffer was performed. Histologic analysis followed. MEASUREMENTS AND MAIN RESULTS: Gas exchange increased markedly in the animals that underwent partial liquid ventilation compared with the gas-ventilated animals (PaO2 at 90 mins: gas ventilation-treatment group, 40 +/- 8 torr [5.3 +/- 1.1 kPa]; partial liquid ventilation-treatment group, 108 +/- 60 torr [14.4 +/- 8.0 kPa]; p = .004). Lung histologic analysis demonstrated a better overall diffuse alveolar damage score (partial liquid ventilation-treatment group, 12.4 +/- 1.4; gas ventilation-treatment group, 15.0 +/- 1.7; p = .01). In the partial liquid ventilation-treatment group, we observed an increase in mean alveolar diameter (partial liquid ventilation-treatment group, 82.4 +/- 2.9 microm; gas ventilation-treatment group, 67.7 x 3.9 microm; p = .0022) and a decrease in the number of alveoli per high-power field (partial liquid ventilation-treatment group, 25.7 +/- 0.9, gas ventilation-treatment group, 31.4 +/- 2.5; p = .0022), in septal wall thickness (partial liquid ventilation-treatment group, 6.0 +/- 0.6 microm; gas ventilation-treatment group, 8.3 +/- 1.0 microm; p = .0033), and in mean capillary diameter (partial liquid ventilation-treatment group, 13.0 +/- 0.8 microm; gas ventilation-treatment group, 19.9 +/- 1.4 microm; p = .0022). CONCLUSIONS: Partial liquid ventilation is associated with notable improvement in gas exchange and with a reduction in the histologic and morphologic changes observed in an oleic acid model of acute lung injury.

Animals↗

PubMed1998

Neutrophil accumulation is reduced during partial liquid ventilation.

OBJECTIVE: This study evaluates the ability of perflubron to inhibit pulmonary neutrophil accumulation during partial liquid ventilation (PLV) in the setting of acute lung injury. DESIGN: Randomized, controlled, nonblinded study. SETTING: Research laboratory at a university. SUBJECTS: Male, Sprague-Dawley rats (n = 120, 506 +/- 42 g). INTERVENTIONS: Animals were divided into eight groups (n = 15 in each group, of which n = 12 for myeloperoxidase content and n = 3 for histologic neutrophil counting): a) GV-CVF group, animals received gas ventilation (GV) with the induction of lung injury using cobra venom factor (CVF); b) PLV-CVF group, animals received partial liquid ventilation before the induction of lung injury; c) PEEP-CVF group, animals received positive end-expiratory pressure (PEEP) before the administration of cobra venom factor; d) CVF-PLV group, animals received partial liquid ventilation after cobra venom factor; e) CVF-PEEP group, animals received PEEP after cobra venom factor; f) PLV only group, animals received partial liquid ventilation only; g) GV only group, animals received gas ventilation only; and h) NVSBA group, nonventilated spontaneous breathing animals. MEASUREMENTS AND MAIN RESULTS: After the experimental period, total lung myeloperoxidase content was significantly decreased in the PLV-CVF (0.29 +/- 0.08, p = .02) and PEEP-CVF (0.34 +/- 0.04, p = .01) groups when compared with the GV-CVF group (0.62 +/- 0.07). When compared with the GV-CVF group, a trend toward a reduction in myeloperoxidase was observed in the CVF-PLV (0.42 +/- 0.05, p = .07) and the CVF-PEEP (0.39 +/- 0.06, p = .07) groups. When compared with the cobra venom factor only group (GV-CVF 47 +/- 2 neutrophils/high-power field), reductions in neutrophil count were observed in all groups (neutrophils/high-power field): PLV-CVF (20 +/- 2, p = .009); PEEP-CVF (24 +/- 1, p = .01); CVF-PLV (30 +/- 2, p = .03); and CVF-PEEP (37 +/- 1, p = .04). CONCLUSION: These data suggest that both partial liquid ventilation and PEEP result in a reduction in neutrophil accumulation in the setting of acute lung injury.

Animals↗

PubMed1998

The pattern of early lung parenchymal and air space injury following acute blood loss.

UNLABELLED: Acute lung injury is a frequent clinical occurrence following blood loss and trauma. The nature of this injury remains poorly understood. OBJECTIVE: To examine the relative parenchymal and intra-alveolar distribution of inflammation in a rat model of hemorrhage and resuscitation. METHODS: Rats were anesthetized and subjected to hemorrhage followed by resuscitation with shed blood and saline. Myeloperoxidase activity of lung homogenates and cytology of bronchoalveolar lavage fluid were used to measure total lung and intra-alveolar neutrophil invasion. Extravasation of i.v.-administered [125I]-albumin was used to determine total lung and alveolar permeability. Permeability results were analyzed using their base-10 logarithmic transformations. RESULTS: 86 animals were studied. Whole-lung myeloperoxidase activity was increased (control = 0.34 +/- 0.16 units, injured = 0.84 +/- 0.43 units, p < 0.01), while there was no difference in intra-alveolar leukocyte counts (injured = 1.85 +/- 1.30 x 10(5)/mL, control = 2.44 +/- 1.75 x 10(5)/mL, p = 0.40), suggesting that the cellular component of the injury was more severe in the intravascular and interstitial spaces. There was a strong trend toward increased permeability in the interstitial compartment, and a significant increase in permeability in the intra-alveolar compartment (whole-lung permeability: control = -0.27 +/- 0.19 units, injured = 0.10 +/- 0.55 units, p = 0.06; alveolar permeability: control = -2.00 +/- 0.47 units, injured = -1.32 +/- 0.49 units, p < 0.01), suggesting that the loss of integrity to macromolecules was not limited to the interstitium. CONCLUSION: Hemorrhage and resuscitation resulted in an acute lung injury characterized by extravasation of intravascular protein into both the interstitium and the intra-alveolar space. Neutrophil invasion of the lung was demonstrable only in the interstitial compartment.

Animals↗

PubMed1998

Partial liquid ventilation improves gas exchange and increases EELV in acute lung injury.

Gas exchange is improved during partial liquid ventilation with perfluorocarbon in animal models of acute lung injury. The specific mechanisms are unproved. We measured end-expiratory lung volume (EELV) by null-point body plethysmography in anesthetized sheep. Measurements of gas exchange and EELV were made before and after acute lung injury was induced with intravenous oleic acid to decrease EELV and worsen gas exchange. Measurements of gas exchange and EELV were again performed after partial liquid ventilation with 30 ml/kg of perfluorocarbon and compared with gas-ventilated controls. Oxygenation was significantly improved during partial liquid ventilation, and EELV (composite of gas and liquid) was significantly increased, compared with preliquid ventilation values and gas-ventilated controls. We conclude that partial liquid ventilation may directly recruit consolidated alveoli in the lung-injured sheep and that this may be one mechanism whereby gas exchange is improved.

Animals↗

PubMed1998

Computer tomographic assessment of perfluorocarbon and gas distribution during partial liquid ventilation for acute respiratory failure.

The average in vivo chest computed tomographic (CT) attenuation number (air = -1,000, soft tissue = 0, perflubron = +2,300 Hounsfield units [HU]) of 10 ventrodorsal-oriented lung segments was calculated to assess the distribution of gas and perflubron in 14 oleic acid lung-injured adult sheep during partial liquid ventilation (PLV, n = 7) or gas ventilation (GV, n = 7). Partial liquid ventilation was associated with a significant decrease in shunt fraction (PLV = 40 +/- 12%, GV = 76 +/- 12%, p = 0.004). Computed tomographic attenuation data during expiration (HUexp) demonstrated minimal gas aeration in GV animals in the dependent (segments 6-10) lung zones (HUexp = -562 +/- 108 for segments 1-5, HUexp = -165 +/- 104 for segments 6-10, p = 0.015). During PLV, perflubron was predominantly distributed to the dependent lung regions (HUexp = 579 +/- 338 for segments 1-5, HUexp = 790 +/- 149 for segments 6-10, p = 0.04). The ratio of the inspiratory to expiratory HU (HUinsp/exp) was greater in dependent than nondependent regions (mean HUinsp/exp segments 1-5 = 0.56, segments 6-10 = 0.81, p = 0.01), indicating that during inspiration relatively more gas than perflubron was distributed to the nondependent lung regions. We conclude that during PLV in this lung injury model, (1) gas exchange is improved when compared with gas ventilation, (2) perflubron is distributed predominantly to the dependent regions of the lung, and (3) although gas is distributed throughout the lung with each inspiration, more gas than perflubron goes to the nondependent lung regions.

Acute Disease↗

PubMed1998

Congenital diaphragmatic hernia survival and use of extracorporeal life support at selected level III nurseries with multimodality support.

BACKGROUND: Congenital diaphragmatic hernia (CDH) has been cited to have a mortality rate of 50%. There have been multiple studies at individual institutions demonstrating potential benefits from various strategies including extracorporeal life support (ECLS), delayed repair, and lower levels of ventilator support. There has been no multicenter survey of institutions offering these modalities to describe the current use of ECLS and survival of these infants. In addition, the relationship between the number of patients with CDH managed at an individual institution and outcome has not been evaluated. METHODS: We queried 16 level III neonatal intensive care centers on the use of ECLS and survival of infants with CDH who were treated during 2 consecutive years (1993 to 1995). Data are presented as mean +/- SEM, median, and range. RESULTS: Data were collected on 411 patients. Of these, 71% +/- 8% were outborn and 8% +/- 3% were considered nonviable. Overall survival of CDH infants was 69% +/- 4% (range, 39% to 95%). The survival rate of infants on ECLS was 55% +/- 4%, whereas survival of infants not requiring ECLS was significantly increased at 81% +/- 5% (p = 0.005). The mean rate of ECLS use was 46% +/- 2%. There was no correlation between the number of cases per year at an individual institution and overall survival, ECLS survival, or ECLS use (r = 0.341, 0.305, and 0.287, respectively). There was also no correlation between case volume at an individual institution and ECLS survival (r = 0.271). CONCLUSIONS: The current survival rate and rate of ECLS use in infants with CDH at level III neonatal intensive care units in the United States are 69% +/- 4% and 46% +/- 2%, respectively. There is no correlation between the yearly individual center experience with managing CDH and rate of ECLS use or outcome.

Extracorporeal Circulation↗

PubMed1997

A comparison of the efficacy of pyloromyotomy and pyloroplasty in patients with gastroesophageal reflux and delayed gastric emptying.

PURPOSE: Delayed gastric emptying (DGE) in children with gastroesophageal reflux (GER) is often treated with a gastric emptying procedure. Although pyloroplasty is the most common gastric emptying procedure performed, pyloromyotomy is easier to perform and is associated with less morbidity. The aim of this study was to compare the efficacy of pyloromyotomy and pyloroplasty in children with DGE and GER undergoing a fundoplication. MATERIALS AND METHODS: We reviewed the charts of 54 patients with DGE who underwent pyloromyotomy (n = 29), or pyloroplasty (n = 25) along with a fundoplication. A technetium 99-labeled sulfur colloid liquid-phase gastric emptying study (GES) was performed in the pre- and early postoperative period (within 6 months after operation). Normal stomach emptying was defined as greater than 40% at 1 hour. Comparisons were made with regard to postoperative complication rate, incidence of redo fundoplication, length of postoperative hospital stay, and pre- and postoperative GES. RESULTS: The pyloroplasty and pyloromyotomy group were comparable in terms of age, sex, operative indications, and neurological status. There was no significant difference in the GES between the two groups preoperatively. There was a trend toward a decreased incidence of early postoperative complications including gas bloat, wound infection, pneumonia, dysphagia, bowel obstruction and dumping syndrome in the pyloromyotomy (8, 28%) when compared with the pyloroplasty group (12, 48%, P = .10). The mean postoperative hospital stay was 10.6 +/- 1.4 days for the pyloroplasty group and 7.6 +/- 1.0 days for the pyloromyotomy group (P + .08). The incidence of a redo fundoplication was 8% in the pyloroplasty and 7% in the pyloromyotomy group. Postoperative gastric emptying increased significantly in both groups (pyloroplasty group, from 18.1 +/- 3.1 to 49.5 +/- 7.9%, P = .0005; pyloromyotomy group, from 19.3 +/- 2.1 to 41.2 +/- 3.7%, P = .0001). There was no significant difference in the postoperative GES between the two groups (P = .289). CONCLUSION: Both pyloroplasty and pyloromyotomy performed in conjunction with a fundoplication resulted in a significant increase in early postoperative gastric emptying. There was no advantage of pyloroplasty over pyloromyotomy during this follow-up period. These data suggest that pyloromyotomy is an effective gastric emptying procedure in children with GER and DGE.

Child↗

PubMed1997

Prenatal ultrasonography frequently fails to diagnose congenital diaphragmatic hernia.

Despite increased use of prenatal ultrasonography and well-defined guidelines to aid in the detection of congenital diaphragmatic hernia (CDH), approximately half of neonates born with CDH undergo a prenatal scan that does not diagnose the defect. The purpose of this study was to (1) examine the use of prenatal ultrasonography in neonates with CDH, (2) determine possible reasons that contributed to the failure to detect the abnormality, and (3) evaluate the clinical impact of a diagnostic versus a nondiagnostic study. From 1985 to 1995, 136 consecutive neonates with CDH symptomatic within 24 hours of birth were treated at the University of Michigan Medical Center. Medical records and a University of Michigan CDH database were reviewed for prenatal ultrasound status, side of herniation, site of birth, survival, and extracorporeal life support (ECLS) use. Sonograms that did not diagnose CDH were collected and reviewed by a radiologist for possible-reasons why the diagnosis was missed. Over the 10-year period, use of ultrasonography increased from 33% to 100%, but the false-negative rate remained approximatedly 55%. In reviewing 40 nondiagnostic studies in 25 patients, 25% had technical difficulties, 57% failed to follow established guidelines (localization of the stomach and visulization of the heart with all four chambers), and 33% missed findings (intrathoracic stomach and mediastinal shift) consistent with CDH. There was no significant difference in survival or use of ECLS between neonates with a diagnostic versus nondiagnostic study (53% v 77% survival, P = 0.09; 64% v 42% ECLS, P = .29) Careful attention to following established guidelines and an increased appreciation for the abnormalities would be expected to increase the sensitivity of ultrasonography in detecting CDH. Increased prenatal diagnosis will allow for thorough evaluation for associated malformations, detection of chromosomal abnormalities, and early referra with intrauterine transport to a tertiary care center before delivery.

False Negative Reactions↗

PubMed1997

Conservative management of mesenchymal hamartoma of the liver.

The natural history of mesenchymal hamartoma of the liver is poorly understood. This case demonstrates the course of a biopsy-proven mesenchymal hamartoma using sequential computed tomography (CT) examinations. These CT scans show initial expansion of the lesion with subsequent involution. The spontaneous resolution in this patient suggests the possibility of conservative management of asymptomatic mesenchymal hamartomas. The case is presented, and the literature on mesenchymal hamartoma is reviewed.

Hamartoma↗

PubMed1997

Distribution of pulmonary blood flow and total lung water during partial liquid ventilation in acute lung injury.

BACKGROUND: Gas exchange is improved during partial liquid ventilation (PLV) with perfluorocarbon in animal models of acute lung injury. The mechanisms are not fully defined. We hypothesize that redistribution of pulmonary blood flow (PBF) along with redistribution of, and decrease in, total lung water (TLW) during PLV may improve oxygenation. METHODS: We characterized PBF and TLW in anesthetized adult dogs by using positron emission tomography with H2(15)O. Measurements of gas exchange, PBF, and TLW were made before and after acute lung injury was induced with intravenous oleic acid. The same measurements were made during PLV (with 30 ml/kg perfluorocarbon) and compared with gas ventilated (GV) controls. RESULTS: Oxygenation was significantly improved during PLV. PBF redistributed from the dependent zone of the lung to the nondependent zones, thus potentially improving ventilation/perfusion relationships. However, a similar pattern of PBF redistribution was observed during GV such that there was no significant difference between groups. TLW redistributed in a similar pattern during PLV. By quantitative measurements, PLV ameliorated the continued accumulation of TLW compared with GV animals. CONCLUSIONS: We conclude that PBF and TLW redistribution and attenuation of increases in TLW may contribute to the improvement in gas exchange during PLV in the setting of acute lung injury.

Animals↗

PubMed1997

Oxygen dynamics during partial liquid ventilation in a sheep model of severe respiratory failure.

BACKGROUND: We evaluated the relationship of dose of perflubron and gas tidal volume to oxygen dynamics during partial liquid ventilation in the setting of respiratory failure. METHODS: Lung injury was induced in 16 sheep by using right atrial injection of 0.15 ml/kg oleic acid. Animals were ventilated with 15 ml/kg gas tidal volume and stabilized. Animals were then divided into three groups: (1) gas ventilation with a tidal volume of 15 ml/kg (control, GV, n = 5); (2) partial liquid ventilation at a gas tidal volume of 15 ml/kg with 10 ml/kg incremental pulmonary dosage of perflubron from 10 to 50 ml/kg (best fill, BF, n = 6); (3) administration of 35 ml/kg perflubron pulmonary dose with 5 ml/kg incremental increase in gas tidal volume from 10 to 30 ml/kg (best tidal volume, BTV, n = 5). RESULTS: Arterial oxygen saturation increased with increasing dose of perflubron and gas tidal volume (BF, p = 0.01; BTV, p = 0.001). A simultaneous trend toward a reduction in cardiac index was observed with increasing dose of perflubron (BF, p = 0.01). Maximal increase in mixed venous oxygen saturation was observed in the BF and BTV groups at a cumulative perflubron dose of 40 ml/kg and a gas tidal volume of 20 ml/kg, respectively. CONCLUSIONS: In this sheep lung injury model oxygenation improves with incremental increases in perflubron dose or gas tidal volume, and the mixed venous oxygen saturation appears to be optimal at a cumulative perflubron dose of 40 ml/kg and a gas tidal volume of 20 ml/kg.

Animals↗

PubMed1997

Extracorporeal life support for 100 adult patients with severe respiratory failure.

OBJECTIVE: The authors retrospectively reviewed their experience with extracorporeal life support (ECLS) in 100 adult patients with severe respiratory failure (ARF) to define techniques, characterize its efficacy and utilization, and determine predictors of outcome. SUMMARY BACKGROUND DATA: Extracorporeal life support maintains gas exchange during ARF, providing diseased lungs an optimal environment in which to heal. Extracorporeal life support has been successful in the treatment of respiratory failure in infants and children. In 1990, the authors instituted a standardized protocol for treatment of severe ARF in adults, which included ECLS when less invasive methods failed. METHODS: From January 1990 to July 1996, the authors used ECLS for 100 adults with severe acute hypoxemic respiratory failure (n = 94): paO2/FiO2 ratio of 55.7+/-15.9, transpulmonary shunt (Qs/Qt) of 52+/-22%, or acute hypercarbic respiratory failure (n = 6): paCO2 84.0+/-31.5 mmHg, despite and after maximal conventional ventilation. The technique included venovenous percutaneous access, lung "rest," transport on ECLS, minimal anticoagulation, hemofiltration, and optimal systemic oxygen delivery. RESULTS: Overall hospital survival was 54%. The duration of ECLS was 271.9+/-248.6 hours. Primary diagnoses included pneumonia (49 cases, 53% survived), adult respiratory distress syndrome (45 cases, 51 % survived), and airway support (6 cases, 83% survived). Multivariate logistic regression modeling identified the following pre-ECLS variables significant independent predictors of outcome: 1) pre-ECLS days of mechanical ventilation (p = 0.0003), 2) pre-ECLS paO2/FiO2 ratio (p = 0.002), and 3) age (years) (p = 0.005). Modeling of variables during ECLS showed that no mechanical complications were independent predictors of outcome, and the only patient-related complications associated with outcome were the presence of renal failure (p < 0.0001) and significant surgical site bleeding (p = 0.0005). CONCLUSIONS: Extracorporeal life support provides life support for ARF in adults, allowing time for injured lungs to recover. In 100 patients selected for high mortality risk despite and after optimal conventional treatment, 54% survived. Extracorporeal life support is extraordinary but reasonable treatment in severe adult respiratory failure. Predictors of survival exist that may be useful for patient prognostication and design of future prospective studies.

Adolescent↗

PubMed1997

Mortality is directly related to the duration of mechanical ventilation before the initiation of extracorporeal life support for severe respiratory failure.

OBJECTIVE: To investigate the relationship between the period of mechanical ventilation before extracorporeal life support and survival in patients with respiratory failure. DESIGN: Retrospective review. SETTING: Surgical intensive care unit at a university medical center. PATIENTS: Thirty-six consecutive adult patients with severe respiratory failure managed with extracorporeal life support. INTERVENTIONS: Extracorporeal life support was utilized in 36 acute respiratory failure adult patients with a variety of diagnoses and an estimated mortality rate of > 90%. Management protocols were followed before and during extracorporeal life support. The 36 patients were physiologically similar before extracorporeal life support was initiated: shunt of 48 +/- 17%; F10(2) of 1.0 +/- 0.1; peak inspiratory pressure of 56 +/- 16 cm H2O; positive end-expiratory pressure of 14 +/- 6 cm H2O; and respiratory rate of 23 +/- 10 breaths/ min. Ventilation was utilized for 1 to 17 days before extracorporeal life support. Typical lung rest settings during extracorporeal life support were F10(2) of 0.40, peak inspiratory pressure of 30 cm H2O, positive end-expiratory pressure of 10 cm H2O, and respiratory rate of 6 breaths/min. Death was almost always secondary to end-stage pulmonary failure. MEASUREMENTS AND MAIN RESULTS: Survival (hospital discharge) in these 36 patients was inversely associated with the number of days of preextracorporeal life support ventilation, with a 50% mortality rate predicted by logistic regression after 5 days of mechanical ventilation. The overall survival rate was 18 (50.0%) of 36 patients. CONCLUSIONS: In severe acute respiratory failure treated with lung rest and extracorporeal life support, a predicted 50% mortality rate was associated with 5 days of preextracorporeal life support mechanical ventilation.

Adult↗

PubMed1997

Prolonged extracorporeal life support (ECLS) for varicella pneumonia.

OBJECTIVE: To review the institutional experience of a national tertiary referral center for extracorporeal life support (ECLS) in severe varicella pneumonia. DATA SOURCES: Hospital records and ECLS flow sheets. STUDY SELECTION: All pediatric (nonneonatal) and adult patients who were treated for varicella pneumonia with ECLS at the University of Michigan Medical Center between 1986 and 1995. DATA EXTRACTION: Diagnosis of varicella pneumonia was made by history of recent exposure to chickenpox, progressive dyspnea, fever, a characteristic diffuse, vesicular rash, and a supporting chest roentgenogram. Indications for ECLS included a shunt fraction of > 30% or PaO2/FlO2 ratio of < 80 despite maximal conventional therapy, which included aggressive diuresis, blood transfusions to optimize oxygen-carrying capacity, pressure-controlled/inverse-ratio ventilation, and intermittent prone positioning. DATA SYNTHESIS: Between 1986 and 1995, 191 patients were referred for ECLS. Among these patients, there were 51 (27%) cases of viral pneumonia, of which nine cases were due to acute varicella-zoster infection. Intravenous acyclovir was administered to eight of the nine patients. Of the nine patients, two patients improved using conventional ventilator management, and seven patients underwent ECLS. Overall survival on ECLS was 71% (5/7). The mean (+/-SD) alveolar-arterial oxygen gradient and PaO2/FlO2 ratio were 533 +/- 101 torr (71.3 +/- 13.5 kPa) and 67 +/- 24, respectively. The median duration of mechanical ventilation before ECLS and the subsequent duration of ECLS were 4 and 12.8 days, respectively. One of the deaths was from progressive right heart failure secondary to pulmonary hypertension and the other death was from overwhelming Pseudomonas sepsis. CONCLUSIONS: Early recognition of imminent pulmonary failure and rapid institution of ECLS are critical in the successful management of severe, life-threatening varicella pneumonia.

Acyclovir↗

PubMed1997

Acute respiratory distress syndrome: CT findings during partial liquid ventilation.

To describe the computed tomographic (CT) appearance of perflubron-filled lungs during partial liquid ventilation to treat acute respiratory distress syndrome, scans of the thorax were obtained in nine patients between June 1994 and December 1995. The distribution of perflubron was gravity dependent in four patients, with a mean interval of 6.25 days between scanning and perflubron administration; was patchy in four patients (mean interval, 16 days); and was homogeneous in one patient (interval, 3 days). Extraparenchymal perflubron was seen in intrathoracic lymph nodes (n = 4), supraclavicular nodes (n = 2), axillary nodes (n = 1), and both the retroperitoneum and the mediastinum (n = 2). In one patient, perflubron was seen in a pneumatocele and the pleural space. The distribution of perflubron in the lungs is typically gravity dependent.

Adolescent↗