Table 1:
Summary data (median, 25–75% range) for “analgesic” remifentanil concentrations. Data are presented separately for the different orders of naloxone injection (Cohort A-C). The levels of significance for each comparison are shown in fig.4.
| Cohort A: “analgesic” remifentanil concentration, naloxone injection into the Parabrachial Nucleus/ Kölliker-Fuse Complex, preBötzinger Complex, and Caudal Medullary Raphe | ||||||
|---|---|---|---|---|---|---|
| Control | IV remifentanil | Naloxone PBN/KF | Naloxone PBN/KF + preBötC | Naloxone PBN/KF + preBötC + CMR | IV Naloxone | |
| Number of animals | 11 | 11 | 11 | 11 | 11 | 11 |
| Respiratory rate (breaths per minute) | 31 (30–36) | 16 (15–17) | 22 (19–25) | 28 (26–33) | 36 (34–41) | 41 (39–44) |
| Inspiratory duration (sec) | 0.8 (0.7–0.9) | 1.4 (1.3–1.6) | 1.2 (1.0–1.4) | 0.9 (0.9–1.1) | 0.8 (0.7–0.9) | 0.7 (0.6–0.8) |
| Expiratory duration (sec) | 1.1 (0.9–1.2) | 2.5 (2.1–2.8) | 1.8 (1.3–1.8) | 1.3 (1.0–1.3) | 0.9 (0.8–1.0) | 0.8 (0.7–0.9) |
| Peak phrenic activity (%) | 100 | 86 (78–89) | 91 (85–101) | 95 (88–118) | 96 (84–125) | 119 (107–154) |
| Input to inspiratory off-switch ^ | 1.8 (1.7–1.9) | 1.3 (1.3–1.4) | 1.4 (1.3–1.6) | 1.7 (1.5–1.7) | 2.0 (2.0–2.5) | 2.0 (1.9–2.3) |
| Input to inspiratory on-switch ^ | 1.5 (1.5–1.7) | 1.1 (1.1–1.1) | 1.2 (1.2–1.4) | 1.4 (1.4–1.6) | 1.7 (1.6–1.9) | 1.9 (1.7–2.0) |
| Cohort B: “analgesic” remifentanil concentration, naloxone injection into the Caudal Medullary Raphe, preBötzinger Complex, and Parabrachial Nucleus/ Kölliker-Fuse Complex | ||||||
| Control | IV remifentanil | Naloxone CMR | Naloxone CMR + preBötC | Naloxone CMR + preBötC + PBN/KF | IV Naloxone | |
| Number of animals | 10 | 10 | 10 | 10 | 10 | 10 |
| Respiratory rate (breaths per minute) | 36 (28–42) | 18 (14–20) | 35 (28–40) | 40 (30–48) | 43 (34–52) | 45 (40–53) |
| Inspiratory duration (sec) | 0.8 (0.8–0.9) | 1.3 (1.1–1.4) | 0.7 (0.7–1.0) | 0.7 (0.6–0.9) | 0.7 (0.6–0.8) | 0.6 (0.6–0.7) |
| Expiratory duration (sec) | 0.9 (0.7–1.3) | 2.2 (1.8–2.8) | 1.0 (0.9–1.2) | 0.8 (0.6–1.1) | 0.8 (0.6–1.0) | 0.7 (0.6–0.8) |
| Peak phrenic activity (%) | 100 | 92 (89–93) | 104 (98–113) | 111 (106–122) | 113 (109–117) | 127 (108–138) |
| Input to inspiratory off-switch ^ | 1.8 (1.6–1.9) | 1.4 (1.3–1.5) | 2.0 (1.6–2.1) | 2.1 (1.6–2.2) | 2.1 (1.8–2.3) | 2.1 (2.0–2.3) |
| Input to inspiratory on-switch ^ | 1.6 (1.3–1.9) | 1.1 (1.1–1.2) | 1.5 (1.4–1.7) | 1.8 (1.5–2.1) | 1.9 (1.6–2.3) | 2.0 (1.8–2.3) |
| Cohort C: “analgesic” remifentanil concentration, naloxone injection into the preBötzinger Complex and Caudal Medullary Raphe | ||||||
| Control | IV remifentanil | Naloxone preBötC | Naloxone preBötC + CMR | IV Naloxone | ||
| Number of animals | 5 | 5 | 5 | 5 | 5 | |
| Respiratory rate (breaths per minute) | 34 (28–36) | 17 (14–19) | 27 (26–32) | 33 (28–43) | 40 (32–48) | |
| Inspiratory duration (sec) | 0.8 (0.8–0.8) | 1.2 (1.1–1.3) | 0.9 (0.9–1.0) | 0.8 (0.6–0.8) | 0.7 (0.5–0.8) | |
| Expiratory duration (sec) | 1.0 (0.8–1.3) | 2.4 (2.0–2.8) | 1.3 (1.0–1.4) | 1.0 (0.8–1.4) | 0.7 (0.7–1.2) | |
| Peak phrenic activity (%) | 100 | 97 (86–101) | 107 (92–127) | 108 (91–112) | 94 (93–114) | |
| Input to inspiratory off-switch ^ | 1.8 (1.8–1.9) | 1.4 (1.4–1.5) | 1.7 (1.6–1.7) | 1.8 (1.8–2.3) | 2.0 (1.9–2.4) | |
| Input to inspiratory on-switch ^ | 1.6 (1.4–1.8) | 1.1 (1.1–1.2) | 1.4 (1.3–1.6) | 1.6 (1.3–1.8) | 1.9 (1.5–2.0) | |
^
Values are relative to the threshold for phase-switch, which is set at 1 in our model. IV: intravenous, PBN/KF: Parabrachial Nucleus/Kölliker-Fuse Complex, preBötC: preBötzinger Complex, CMR: Caudal Medullary Raphe.