2006 OPEN FORUM Abstracts
A REVIEW OF ISOFLURANE USE IN A PEDIATRIC ICU
David Heitz RRT-NPS, Patricia Donald RRT, Julianne Socha RRT,
Peter Betit RRT-NPS, David A.Turner MD.
Children's Hospital Boston and
Harvard
Medical
School
,
Boston
,
MA
Introduction: Isoflurane (Forane®) is an
anesthetic agent with bronchodilator properties. Isoflurane
(ISO) is used in our PICU as an adjunct in the treatment of severe bronchospasm refractory to conventional therapies. We use a
modified Servo 900C ventilator (Maquet Inc,
Bridgewater
,
NJ
) fitted with an ISO vaporizer and scavenging system.
We report our experience over a six year period from 01/99 - 03/06.
Methods: The medical records of
patients treated with ISO were reviewed.
We evaluated demographics, blood gas data, ISO doses, and duration of
ISO therapy. PaCO2 measurements prior ISO were compared with
subsequent values obtained at 1, 4, and 8 hours. A positive response was
defined as a decrease in PaCO2 ³ 5 mmHg. The Wilcoxon Signed
Ranks Test was used to evaluate statistical significance.
| PaCO2 (mmHg) | ||||
| Patient | Pre-tx | 1 Hr | 4 Hr | 8 Hr |
| 1 | 95 | 77 | 67 | 44 |
| 2 | 121 | 71 | 55 | 37 |
| 3 | 63 | 57 | 59 | 61 |
| 4 | 187 | 85 | 44 | 39 |
| 5 | 68 | 68 | 69 | 56 |
| 6 | 83 | 76 | 62 | 61 |
| 7 | 60 | 60 | 52 | 54 |
| 8 | 72 | 47 | 46 | 60 |
| 9 | 121 | 49 | 47 | 53 |
| 10 | 95 | 105 | 92 | 70 |
| 11 | 67 | 77 | 66 | 51 |
| 12 | 155 PvCO2 | 115 | 75 | 70 |
| 13 | 160 | 109 | 72 | 57 |
| 14 | 58 | 63 | 53 | 51 |
| 15 | 133 | 105 | 53 | 51 |
| 16 | 56 | 46 | 42 | |
Results: Sixteen
patients, age 5 mos-24 yrs, received ISO; 12 status asthmaticus,
2 reactive airway disease, 1 bronchiolitis, and 1
chronic lung disease. The average initial ISO dose was 0.5%, range 0.2-1%. The
average ISO duration was 58 hours, range 7-240 hours. The average maximum ISO
dose was 1%, range 0.3-2.1%. There was a statistically significant decrease in
PaCO2 at 1 hour (p=0.009), 4 hours (p=0.001), and 8 hours (p=0.001)
(see table). A positive response was seen in 11/16 patients. Five patients had
delayed responses; 2 at hour 4, and 3 at hour 8. Overall, l5/16 patients
demonstrated sustained improvement with ISO. There was also statistically
significant evidence of continued improvement during ISO when comparing PaCO2 between 1 and 4 hours (p = 0.001), and 1 and 8 hours (p=0.004). All patients were successfully weaned from
ISO, and all but one survived to discharge.
Conclusion: From our
experience, the vast majority of patients treated with ISO had an immediate and
sustained response as defined by improvement in CO2 elimination. The patients who did not initially
respond eventually demonstrated improvement within 8 hours of starting
therapy. ISO appears to be an effective
adjunct therapy in the treatment of respiratory failure due to severe and
potentially life threatening bronchospasm.