Complication of nasal endotracheal intubation

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Editorial correspondence

The Journal o f Pediatrics July 1983

the diastolic properties of the left ventricle. To establish the mechanism producing increased P W P in our patients, it is helpful to study the trend in other variables as the dobutamine dose was increased. First, right atrial pressure (RAP) remained constant. Although we recognize the pitfalls in using filling pressure as an index of preload, we elected to infuse fluid as needed to maintain R A P at a constant level during the study. Second, heart rate and the mean pulmonary and systemic blood pressures remained constant during the infusion. Third, cardiac index and stroke work index increased as the dobutamine dose was advanced. Three mechanisms could account for the increase in P W P while the cardiac index increased and the afterload decreased: (1) disparate ventricular function, (2) pulmonary venoconstriction, and (3) alteration in the left ventricular diastolic properties. The first mechanism implies that the infusion of dobutamine created a disparity between right and left ventricular function; thus, as stroke volume increased from the right ventricle, the left ventricle could match this increased load only at the expense of elevated PWP. The second mechanism proposes that dobutamine causes selective pulmonary venoconstriction, a finding not previously reported in humans. The third mechanism, which we believe is most likely, assumes that left ventricular compliance fell as dobutamine dose was increased. Factors that reduce left ventricular compliance include myocardial ischemia, positive end-expiratory pressure (PEEP), right ventricular overload, pericardial effusion, and poorly understood drug effects.,2 3 There was no evidence of pericardial effusion or right ventricular overload in our patients, and PEEP was held constant during the study, so drug effect or myocardial ischemia remain as possible explanations. Although our data cannot prove either of these mechanisms, further study of the effect of dobutamine on left ventricular compliance seems warranted.

Ronald M. Perkin, M.D. Daniel L. Levin, M.D. Children's Medical Center 1935 Amelia St. Dallas, TX 75235 REFERENCES 1.

2. 3.

Iskandrian AS, Segal BL, Hakki AH: Left ventricular end-diastolic pressure in evaluating left ventricular function. Clin Cardiol 4:28, 1981. Glantz SA, Parmley W W : Factors which affect the diastolic pressure-volume curve. Circ Res 42:171, 1978. Sibbald W J, Calvin J, Driedger AA: Right and left ventricular preload and diastolic ventricular compliance: Implications for therapy in critically ill patients. In Shoemaker WC, Thompson W L , editors: Critical care medicine, vol 3. Fullerton, Calif., 1982, T h e Society of Critical Care Medicine.

Complication of nasal endotracheal intubation To the Editor." We have had similar results to those found by Spitzer and Fox. 1 In a larger series (377 intubated neonates) we showed nasal endotracheal tubes to last longer (~ = 7.1 _+ S E M = 0.7 days) than oral tubes (X -- 4.2 + S E M = 0.4 days) (P < 0.001); in our

study, extubation after the use of dexamethasone (0.5 m g / kg/day) for 24 hours did not significantly influence the clinical course when compared with control infants. 3,4 One important finding was the increased incidence of acute otitis media in nasally intubated infants (13%), Candida albicans being an often encountered etiologic agent. This complication, not seen when using oral endotracheal tubes, forced us to consider carefully the use of nasal intubation. Because this problem is not mentioned by Spitzer and Fox, we would like to know whether its absence was documented or perhaps not looked for.

Eduardo Halac, M.D. Daniel R. Indiveri, M.D. Ricardo J. Obregbn, R.T. Enrique Bbgub, M.D. Marcelo Casahas, M.D. Neonatal Intensive Care Unit Primer lnstituto Privado de Neonatologia Dean Funes 454--TE 36653/37473/20714 5000 Cordoba Argentina REFERENCES 1.

2.

3.

4.

Spitzer A, Fox W W : Post extubation atelectasis: The role of oral versus nasal endotracheal tubes. J PEDIATR 100:806, 1982. Obregon R J, Halac E, Arias ME, Giovini AC, Halac J: Evaluaci6n de dos t6cnicas de succi6n de via a6rea neonatal. Arch Arg Pediatr 79:188; 1981. lndiveri DR, Halac E: Estado actual de la ventilaci6n Mecfinica Neonatal: Experiencia en C6rdoba y revisi6n de la literatura. Arch Arg Pediatr 79:470, 1981. Halac E, Arias ME, Halac J: The challenge of neonatal I C U and mechanical ventilation in a developing country: A two year experience. Pediatr Res 15:662, 1981.

Reply W e were pleased to see that Dr. Halac and colleagues studied a large number of infants with similar results to our findings. In that study we did not look at the use of corticosteroids in extubation, but we do have a current study intended to examine that therapy. One of the specific concerns that we did have in initiating our original project comparing oral and nasal endotracheal tubes was whether nasal endotracheal tubes would predispose the newborn infant to a higher incidence of acute otitis media. W e did not see any increased incidence of acute otitis media with either type of endotracheal tube, both acutely and in follow-up. In particular, we did not see Candida albicans infections. W e wonder if some technisal d!fferences in use of the endotracheal tubes resulted in their high incidence of fungal infection.

Alan R. Spitzer, M.D. Assistant Professor o f Pediatrics and Obstetrics & Gynecology William W. Fox, M.D. Associate Professor o f Pediatrics University o f Pennsylvania School o f Medicine Philadelphia, PA 19104