Morphine Dose (mg/kg)	Acute vs. chronic	Slope	95% confidence interval	P value	R2
3.2	Acute (30 min)	- 0.18	- 0.40 to + 0.04	0.09	0.36
	Acute (100 min)	0.04	- 0.65 to + 0.73	0.89	0.00
	Chronic*	- 0.73	- 0.95 to - 0.52	<0.01	0.89
5.6	Acute (30 min)	- 0.18	- 0.45 to + 0.08	0.15	0.24
	Acute (100 min)*	- 0.60	- 0.79 to - 0.42	<0.01	0.88
	Chronic*	- 0.87	- 0.95 to - 0.79	<0.01	0.99
10	Acute (30 min)*	- 0.81	- 1.35 to - 0.28	0.01	0.70
	Acute (100 min)*	- 0.80	- 0.92 to - 0.76	<0.01	0.97
	Chronic*	- 0.78	- 0.86 to - 0.71	<0.01	0.99