Thomas Pranikoff

Liquid ventilation in adults, children, and full-term neonates

We evaluated the safety and efficacy of partial liquid ventilation in a series of 19 adults, children, and neonates who were in respiratory failure and on extracorporeal life support. During partial liquid ventilation, the alveolar-arterial oxygen difference decreased from 590 (SE 25) to 471 (42) mm Hg (p = 0.0002) and static pulmonary compliance increased from 0.18 (0.04) to 0.29 (0.04) mL cm H2O-1 kg-1 (p = 0.0002). 11 patients (58%) survived. These preliminary data suggest that partial liquid ventilation can be safely used in patients with severe respiratory failure and may improve lung function.

Initial experience with partial liquid ventilation in pediatric patients with the acute respiratory distress syndrome

OBJECTIVE Liquid ventilation with perfluorocarbon previously has not been reported in pediatric patients with respiratory failure beyond the neonatal period. We evaluated the technique of partial liquid ventilation in six pediatric patients with the acute respiratory distress syndrome of sufficient severity to require extracorporeal life support (ECLS). DESIGN This study was a noncontrolled, phase I/II experimental study with a single group pretest/posttest design. SETTING All studies were performed at a tertiary, pediatric referral hospital at the University of Michigan Medical School. PATIENTS Six pediatric patients, from 8 wks to 5 1/2 yrs of age, with severe respiratory failure requiring ECLS to support gas exchange. INTERVENTIONS After 2 to 9 days on ECLS, perfluorocarbon was administered into the trachea until the dependent zone of each lung was filled. The initial administered was 12.9 +/- 2.3 mL/kg (range 5 to 20). Gas ventilation of the perfluorocarbon-filled lungs (partial liquid ventilation) was then performed. The perfluorocarbon dose was repeated daily for a total of 3 to 7 days, with a cumulative dose of 45.2 +/- 6.1 mL/kg (range 30 to 72.5). MEASUREMENTS AND MAIN RESULTS All measurements of native gas exchange were made during brief periods of discontinuation of ECLS and include PaO2 and the alveolar-arterial oxygen gradient, P(A-a)O2. Static pulmonary compliance, corrected for weight, was also measured directly. The mean PaO2 increased from 39 +/- 6 to 92 +/- 29 torr (5.2 +/- 0.8 to 12.2 +/- 3.9 kPa) over the 96 hrs after the initial dose (p = .021 by repeated-measures analysis of variance). The average P(A-a)O2 decreased from 635 +/- 10 to 499 +/- 77 torr (84.7 +/- 1.3 to 66.5 +/- 10.3 kPa) over the same time period (p = .059), while the mean static pulmonary compliance (normalized for patient weight) increased from 0.12 +/- 0.02 to 0.28 +/- 0.08 mL/cm H2O/kg (p = .01). All six patients survived. Complications potentially associated with partial liquid ventilation were limited to pneumothoraces in two of six patients. CONCLUSIONS Perfluorocarbon may be safely administered into the lungs of pediatric patients with severe respiratory failure on ECLS and may be associated with improvement in gas exchange and pulmonary compliance.

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.

Partial liquid ventilation in newborn patients with congenital diaphragmatic hernia

The authors evaluated the safety and efficacy of liquid ventilation with perfluorocarbon in four newborns with congenital diaphragmatic hernia and severe respiratory failure, who were on extracorporeal life support (ECLS). After 2 to 5 days on the ECLS, perflubron was administered into the trachea until the dependent zone of the lung was filled. The first dose was 6 +/- 1 mL/kg (range, 5 to 8 mL/kg). Gas ventilation of the perflubron-filled lung was performed (partial liquid ventilation). The administration of perflubron was repeated daily for 5 to 6 days, with total cumulative doses of 36 +/- 8 mL/kg (range, 26 to 44 mL/kg). A significant increase in PaO(2) (P = .027 by repeated-measures analysis of variance [ANOVA]), a trend toward an increase in arterial oxygen content (P = .052 by repeated-measures ANOVA), and a significant increase in specific static total pulmonary compliance (P = .007 by repeated-measures ANOVA) were observed after administration of the daily dose of perflubron. PaCO(2) data showed a decreasing trend (P = .08 by repeated measures ANOVA). The authors conclude that perflubron can be safely administered into the lungs of newborn patients with congenital diaphragmatic hernia and severe respiratory failure, and it may be associated with improvement in gas exchange and pulmonary compliance.

Resolution of splenic injury after nonoperative management

Numerous studies have demonstrated success with nonoperative management of splenic injuries in pediatric patients. However, the resolution of the splenic injury has not been previously evaluated. The records of 50 pediatric patients with splenic injuries from blunt trauma treated nonoperatively between 1984 to 1992 were reviewed retrospectively. Abdominal computed tomography (CT) was performed at the time of injury and 6 weeks postinjury in 25 patients. These scans were reviewed and categorized by a modification of a previously reported grading system for parenchymal injury. All patients had healing of the splenic injuries, with complete resolution of the healing process observed at 6 weeks postinjury in 44%. Even those with shattered spleens (n = 6) had consistent improvement in splenic architecture, with resolution of fractures and/or contusions and return of splenic perfusion. Ten (77%) of 13 grade 1 and 2 injuries were completely resolved by the 6-week follow-up examination, whereas only one (8%) of 12 grade 3 to 5 injuries showed radiological resolution of splenic injuries. None of the 25 follow-up CT scans affected clinical decision-making or led to a deviation from the established protocol, which included a 3-month period of reduced activity. All 50 patients did well, without evidence of morbidity, mortality, or complications after return to full activity 3 months postinjury.(ABSTRACT TRUNCATED AT 250 WORDS)

Partial liquid ventilation provides effective gas exchange in a large animal model

PURPOSE The purpose of this study was to show the ability of partial liquid ventilation (PLV) to sustain gas exchange in normal large (50 to 70 kg) adult animals. METHODS Ten adult sheep (53.7 +/- 2.8 kg) were anesthetized and mechanically ventilated. Sequential dosing of perflubron (LiquiVent, Alliance Pharmaceutical Corp, San Diego, CA) was performed to cumulative doses of 10 mL/kg, 20 mL/kg, 40 mL/kg, and 60 mL/kg. Physiological data were assessed at baseline and after each dose. Five animals were rotated through the left decubitus, right decubitus, supine, and prone positions while five animals remained prone throughout the experiment. RESULTS PaO2 and PaCO2 did not change significantly from baseline during administration of perflubron except for the PaO2 in rotated animals when supine (rotated-supine PaO2: baseline = 519 +/- 64 mm Hg; 60 mL/kg = 380 +/- 109 mm Hg, P = .0131). In both groups, static lung compliance (CT) decreased steadily with each successive perflubron instillation (nonrotated CT: baseline = 1.55 +/- 0.22 mL/cm H2O/kg; 60 mL/kg = 0.52 +/- 0.10 ml/cmH2O/kg, P = .0003). CONCLUSIONS These data show that during PLV in this normal animal model, effective gas exchange is sustained and CT decreases with increasing perflubron dose.

Approach to cervicothoracic neuroblastomas via a trap-door incision

Neuroblastomas located in the apex of the hemithorax or in the lower cervical region may make complete resection via a cervical or a thoracic approach difficult. The authors recently managed two patients with cervicothoracic neuroblastomas through an approach using the trap-door incision often applied in the setting of vascular trauma. This approach allowed a successful, complete excision of these tumors, which may have otherwise been difficult.

Transport of unstable respiratory failure patients on extracorporeal life support

Introduct ion: We have used extracorporeal life suppor t (ECLS) to manage 51 cases of severe adult respiratory failure with a 57% surv iva l . T h i r t y e i g h t pa t i en t s f rom ou t s ide ins t i tu t ions r e q u i r e d e m e r g e n t transport. Fourteen of these patients were too unstable to be safely t ransported using conven t iona l ven t i l a t ion and so w e r e placed on bypass at the referring institution. Methods: Diagnoses included ARDS (n = 8), pneumonia (n = 5), and asthma (n = 1). PreECLS ventilator suppor t included: FiO2 = 0.98 + 0.07, Rate = 19 + 5, PIP = 57 + 12, PEEP = 14 + 7. Physiologic indicators of severity of respiratory failure included: SaO2 = 84 + 11, PaO2 = 67 + 43, PaCO2 = 48 + 22, pH = Z33 + 0.16, Q s / Q t = 0.48 + 0.12, AaDO2 = 586 + 76, Murray Vent Score = 3.62 + 0.51. Results: Transport with the patient on ECLS was p e r f o r m e d by g r o u n d a m b u l a n c e without adverse effects. The transport team included two ECLS physicians, two flight nurses, and two ECLS specialists. Distance transported was a median of 43 miles (range 6 248 miles). Median transport t ime was 8.0 h o u r s ( r ange 1.9 13.4 hours ) . Eva lua t ion , in i t i a t ion of b y p a s s and stabil ization pr ior to r e tu rn r equ i red a median of 4.6 hours (range 1.1 7.0 hours). Twelve of the 14 patients (86%) survived to discharge. Total time on bypass was 223 + 201 hours° C o n c l u s i o n : P a t i e n t s w i t h s e v e r e respiratory failure who are too unstable to t r a n s p o r t s a f e l y u s i n g m e c h a n i c a l venti lat ion alone m a y be t ranspor ted on ECLS with a high survival rate. THE FINANCIAL IMPACT OF VIOLENCE ON AIR MEDICAL TRANSPORT