Efficacy and safety of tolazoline for treatment of severe hypoxemia in extremely preterm infants.
OBJECTIVE
To determine the efficacy of tolazoline as a rescue treatment for hypoxemia in preterm infants with respiratory distress syndrome.


METHODS
Retrospective chart review on case series of infants weighing < 750 g at birth who received tolazoline during a severe hypoxemic episode while receiving maximal ventilator support for respiratory distress syndrome. A slow bolus infusion of low dose tolazoline (0.5 mg-2 mg/kg) mixed with plasmanate or normal saline (10 mL/kg) was administered. Outcome measures evaluated included an increase in PaO(2) > or =20 mm Hg from pretreatment value and an increase in oxygen saturation to > or =90%.


RESULTS
Forty-three infants with a mean gestational age and birth weight of 24 weeks and 581 g, respectively, received tolazoline. All infants were mechanically ventilated and required a fraction of inspired oxygen of 1.0. Oxygenation improved in 72% (31/43) of infants with a tolazoline dose of 0.5 to 1.0 mg/kg. Of those who responded, PaO(2) values (mean +/- standard deviation) pretolazoline and posttolazoline were 32 +/- 7.5 mm Hg and 156 +/- 114.9 mm Hg, respectively. In all responders, oxygen saturation increased to > or =90% within 30 minutes of tolazoline administration. Improvement in pH, pCO(2), oxygenation index, and mean airway pressure was also noted. Among nonresponders, pH decreased and pCO(2) increased after tolazoline. Minimal change in blood pressure was noted in both responders and nonresponders. Heart rate decreased by 19 beats per minute among nonresponders compared with an increase of 3 beats per minute in those who responded to tolazoline.


CONCLUSIONS
Tolazoline is an effective treatment of severe resistant hypoxemia in preterm infants who are already on vigorous ventilatory support.
Nuntnarumit
Pracha
P
Department of Pediatrics, Mahidol University, Bangkok, Thailand.
Korones
Sheldon B
SB
Yang
Wenjian
W
Bada
Henrietta S
HS
D001794:Blood Pressure / Q000187:drug effects; D001798:Blood Proteins / Q000627:therapeutic use; D002245:Carbon Dioxide / Q000097:blood / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D005865:Gestational Age; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy; D000860:Hypoxia / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D007262:Infusions, Intravenous; D007363:Intensive Care Units, Neonatal; D007969:Leukomalacia, Periventricular / Q000453:epidemiology; D010100:Oxygen / Q000097:blood / Q000378:metabolism; D011247:Pregnancy; D012121:Respiration, Artificial; D012127:Respiratory Distress Syndrome, Newborn / Q000150:complications / Q000188:drug therapy / Q000628:therapy*; D012709:Serum Albumin; D000075462:Serum Albumin, Human; D012712:Serum Globulins; D012720:Severity of Illness Index; D014043:Tolazoline / Q000008:administration & dosage / Q000627:therapeutic use*; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000627:therapeutic use*
D001798:Blood Proteins; D012709:Serum Albumin; D012712:Serum Globulins; D014665:Vasodilator Agents; D002245:Carbon Dioxide; C008930:plasma protein fraction; D014043:Tolazoline; D010100:Oxygen; D000075462:Serum Albumin, Human