Correspondence

Advances in Mechanical Ventilation

N Engl J Med 2001; 345:1133-1134October 11, 2001

Article

To the Editor:

In his review of the methods available for improving oxygenation and preventing lung injury (June 28 issue),1 we believe that Dr. Tobin made an important omission — namely, high-frequency oscillatory ventilation. High-frequency oscillatory ventilation provides respiratory gas exchange through the use of positive airway pressure–driven tidal breaths that are smaller than the anatomical dead space and breathing frequencies that are several times faster than normal.2,3 The conceptual advantage to high-frequency oscillatory ventilation is that the small tidal volume limits maximal airway pressures, whereas lung recruitment is optimized by the intrinsic positive end-expiratory pressure effect.2,3 Thus, ventilation occurs between upper and lower inflection points on a static pressure–volume curve, the presumed ideal mechanical range for positive-pressure ventilatory support.4

Data in animals have demonstrated the effectiveness of high-frequency oscillatory ventilation in reversing atelectasis, improving oxygenation and lung compliance, and reducing ventilator-induced lung injury.2,3 In the clinical setting, high-frequency oscillatory ventilation has been shown to be capable of achieving an optimal lung-volume strategy and decreasing morbidity and mortality among neonates and children with lung disease, even among those with cases refractory to other types of mechanical ventilation.2,3,5 Data on the outcome of high-frequency oscillatory ventilation in adults are still lacking; however, there appear to be several potential applications for these patients.

High-frequency oscillatory ventilation is an important therapeutic option for patients with respiratory failure and should be considered among the recent advances in mechanical ventilation. In the near future, the combination of high-frequency oscillatory ventilation and other therapies, such as partial liquid ventilation, could minimize the physiological changes associated with positive-pressure ventilation and lead to the ultimate lung-protective ventilatory strategy.

Federico Martinón-Torres, M.D., Ph.D.
Antonio Rodriguez-Nuñez, M.D., Ph.D.
Jose María Martinón-Sánchez, M.D., Ph.D.
Hospital Clínico Universitario de Santiago, 15706 Santiago de Compostela, Spain
fedemartinon@hotmail.com

5 References

1. 1

   Tobin MJ. Advances in mechanical ventilation. N Engl J Med 2001;344:1986-1996
   Full Text | Web of Science | Medline

2. 2

   Martinon Torres F, Rodriguez Nunez A, Jaimovich DG, Martinon Sanchez JM. Ventilación de alta frecuencia oscilatoria en pacientes pediátricos: protocolo de aplicación y resultados preliminares. An Esp Pediatr 2000;53:305-313
   Medline

3. 3

   Wetzel RC, Gioia FR. High frequency ventilation. Pediatr Clin North Am 1987;34:15-38
   Web of Science | Medline

4. 4

   International consensus conferences in intensive care medicine: ventilator-associated lung injury in ARDS. Am J Respir Crit Care Med 1999;160:2118-2124
   Medline

5. 5

   Arnold JH. High-frequency ventilation in the pediatric intensive care unit. Pediatr Crit Care Med 2000;1:93-99
   CrossRef | Medline

Author/Editor Response

Dr. Tobin replies:

To the Editor: My omission of high-frequency oscillatory ventilation was deliberate. Unlike Martinón-Torres and colleagues, I do not consider this method an important therapeutic option.

Research on high-frequency oscillatory ventilation extends back 30 years.1 It is not a recent advance. I agree that research shows that high-frequency oscillatory ventilation has a lot of promise2 and that it is feasible to use this approach in adult patients with acute respiratory failure.3 However, a randomized trial of high-frequency oscillatory ventilation in preterm infants 4 was interrupted because the method was associated with pneumoperitoneum and a 44 percent increase in intracranial hemorrhage, without offering any advantage over conventional ventilation. This trial had serious weaknesses,1 and I would not be surprised if high-frequency oscillatory ventilation turned out to be a useful treatment in certain situations. But it is essential to subject our hunches to scientific analysis. Until we have more persuasive data indicating that high-frequency oscillatory ventilation improves the clinical outcome, I would not list it among standard forms of mechanical ventilation for adult patients — the focus of my article.

Martin J. Tobin, M.D.
Loyola University Medical Center, Maywood, IL 60153
mtobin2@luc.edu

4 References

1. 1

   Bryan AC. The oscillations of HFO. Am J Respir Crit Care Med 2001;163:816-817
   Web of Science | Medline

2. 2

   Yoder BA, Siler-Khodr T, Winter VT, Coalson JJ. High-frequency oscillatory ventilation: effects on lung function, mechanics, and airway cytokines in the immature baboon model for neonatal chronic lung disease. Am J Respir Crit Care Med 2000;162:1867-1876
   Web of Science | Medline

3. 3

   Mehta S, Lapinsky SE, Hallett DC, et al. Prospective trial of high-frequency oscillation in adults with acute respiratory distress syndrome. Crit Care Med 2001;29:1360-1369
   CrossRef | Web of Science | Medline

4. 4

   The HIFI Study Group. High-frequency oscillatory ventilation compared with conventional mechanical ventilation in the treatment of respiratory failure in preterm infants. N Engl J Med 1989;320:88-93
   Full Text | Web of Science | Medline