TY - JOUR
T1 - Disposition and respiratory effects of intrathecal morphine in children
AU - Nichols, David
AU - Yaster, Myron
AU - Lynn, A. M.
AU - Helfaer, M. A.
AU - Deshpande, J. K.
AU - Manson, Paul
AU - Carson, B. S.
AU - Bezman, M.
AU - Maxwell, L. G.
AU - Tobias, J. D.
AU - Grochow, Louise Barnett
PY - 1993
Y1 - 1993
N2 - Background: The extent and duration of respiratory depression after opioid administration are poorly defined in infants and children. Methods: The disposition and respiratory effects of intrathecal morphine were studied in ten patients (ages 4 months-15 yr) after repair of craniofacial defects. Morphine, 0.02 mg/kg, was administered intrathecally before the end of surgery. Postoperatively, we determined the minute ventilation (V(E)) in response to increasing partial pressure of end-tidal carbon dioxide (PET(CO2)) during carbon dioxide rebreathing. The slope (V(E)/PET(CO2)) and intercept (V(E) at PET(CO2) 60 mmHg, V(E) 60) of the carbon dioxide response curve were calculated at 6, 12, and 18 h after morphine administration. Cerebrospinal fluid (CSF) and blood were analyzed for morphine concentration by radioimmunoassay. Results: Mean V(E)/PET(CO2) decreased from a preoperative value of 35.1 ± 3.7 to 16.3 ± 2.8 ml · kg-1 · min-1 · mmHg-1 at 6 h after morphine, and remained depressed to 23.4 ± 2.9 and 23.5 ± 3.3 ml · kg-1 · min-1 · mmHg-1 at 12 h and 18 h, respectively, compared to preoperatively). The infants' (n = 3) V(E)/PET(CO2) at 6 h were 21, 4, and 27 ml · kg-1 · min-1 · mmHg- 1. Mean V(E) 60 decreased from 874 ± 125 to 276 ± 32 ml · kg-1 · min- 1 at 6 h, but then recovered at 12 and 18 h to 491 ± 68 and 567 ± 82 ml · kg-1 · min-1, respectively. The infants' V(E) 60 at 6 h were 350, 142, and 245 ml · kg-1 · min-1. Mean CSF morphine concentration was 2,860 ± 540 ng/ml at 6 h, and decreased to 640 ± 220 and 220 ± 150 ng/ml at 12 and 18 h, respectively. Conclusions: Intrathecal morphine, 0.02 mg/kg, depressed the ventilatory response to carbon dioxide for up to 18 h concomitant with increased CSF morphine concentrations. Infants (4-12 months of age) did not exhibit greater ventilatory depression than did children (2-15 yr of age).
AB - Background: The extent and duration of respiratory depression after opioid administration are poorly defined in infants and children. Methods: The disposition and respiratory effects of intrathecal morphine were studied in ten patients (ages 4 months-15 yr) after repair of craniofacial defects. Morphine, 0.02 mg/kg, was administered intrathecally before the end of surgery. Postoperatively, we determined the minute ventilation (V(E)) in response to increasing partial pressure of end-tidal carbon dioxide (PET(CO2)) during carbon dioxide rebreathing. The slope (V(E)/PET(CO2)) and intercept (V(E) at PET(CO2) 60 mmHg, V(E) 60) of the carbon dioxide response curve were calculated at 6, 12, and 18 h after morphine administration. Cerebrospinal fluid (CSF) and blood were analyzed for morphine concentration by radioimmunoassay. Results: Mean V(E)/PET(CO2) decreased from a preoperative value of 35.1 ± 3.7 to 16.3 ± 2.8 ml · kg-1 · min-1 · mmHg-1 at 6 h after morphine, and remained depressed to 23.4 ± 2.9 and 23.5 ± 3.3 ml · kg-1 · min-1 · mmHg-1 at 12 h and 18 h, respectively, compared to preoperatively). The infants' (n = 3) V(E)/PET(CO2) at 6 h were 21, 4, and 27 ml · kg-1 · min-1 · mmHg- 1. Mean V(E) 60 decreased from 874 ± 125 to 276 ± 32 ml · kg-1 · min- 1 at 6 h, but then recovered at 12 and 18 h to 491 ± 68 and 567 ± 82 ml · kg-1 · min-1, respectively. The infants' V(E) 60 at 6 h were 350, 142, and 245 ml · kg-1 · min-1. Mean CSF morphine concentration was 2,860 ± 540 ng/ml at 6 h, and decreased to 640 ± 220 and 220 ± 150 ng/ml at 12 and 18 h, respectively. Conclusions: Intrathecal morphine, 0.02 mg/kg, depressed the ventilatory response to carbon dioxide for up to 18 h concomitant with increased CSF morphine concentrations. Infants (4-12 months of age) did not exhibit greater ventilatory depression than did children (2-15 yr of age).
KW - Analgesia, postoperative
KW - Analgesics, opioid: intrathecal morphine
KW - Anesthesia, pediatric
KW - Cerebrospinal fluid
KW - Pharmacodynamics
KW - Ventilation, carbon dioxide response
UR - http://www.scopus.com/inward/record.url?scp=0027504722&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027504722&partnerID=8YFLogxK
U2 - 10.1097/00000542-199310000-00015
DO - 10.1097/00000542-199310000-00015
M3 - Article
C2 - 8214752
AN - SCOPUS:0027504722
SN - 0003-3022
VL - 79
SP - 733
EP - 738
JO - Anesthesiology
JF - Anesthesiology
IS - 4
ER -