Table 1.
Maximum Likelihood loadings of morphine and butorphanol change scores on 22 experimental pain modalities.
| Variable | Factor 1 BU Ischemic |
Factor 2 MS Ischemic |
Factor 3 BU TS |
Factor 4 MS Thermal |
Factor 5 MS PPT |
Factor 6 BU Thermal and PPT |
|---|---|---|---|---|---|---|
| BU ischemic unpleasantness |
.927 | |||||
| BU ischemic intensity |
.843 | |||||
| BU ischemic threshold |
.627 | |||||
| MS ischemic intensity |
.883 | |||||
| MS ischemic unpleasantness |
.862 | |||||
| MS ischemic threshold | .643 | |||||
| BU TS at 48°C | .861 | |||||
| BU TS at 46°C | .668 | |||||
| BU TS at 50°C | .586 | |||||
| MS heat threshold | .677 | |||||
| MS heat tolerance | .594 | |||||
| MS TS at 50°C | .503 | |||||
| MS TS at 48°C | .439 | |||||
| MS TS at 46°C | .362 | |||||
| MS PPT ulna | .988 | |||||
| MS PPT trapezius | .496 | |||||
| MS PPT masseter | .396 | |||||
| BU heat tolerance | .536 | |||||
| BU PPT ulna | .490 | |||||
| BU PPT trapezius | .449 | |||||
| BU PPT masseter | .376 | |||||
| BU heat threshold | .309 |
BU: butorphanol; MS: morphine; TS: temporal summation; PPT: pressure pain threshold