Effect of common sedation agents on feline splenic size determined via ultrasonography

Figures & data

Figure 1. Ultrasound images demonstrating position of cursors (connected by solid line) for measurement of splenic thickness. For the head (a) and tail (c) of the spleen, which were imaged in a transverse plane, measurement cursors were placed on the near edge of the parietal capsule margin and the far edge of the visceral capsule margin, adjacent to the indentation from the splenic vein radicle. For the body of the spleen (b), which was imaged in a sagittal plane, the measurement was similarly made from a clearly defined splenic radicle to the opposite surface perpendicular to the long axis of the spleen.

Table 1. Characteristics of cats (n = 24) included in a study comparing the effect of acepromazine (ACE), alfaxalone (ALF) and dexmedetomidine (DEX), all in combination with morphine, on the size of the spleen measured ultrasonographically.

		Group
Characteristics^a	All cats (n = 24)	ACE (n = 8)	ALF (n = 8)	DEX (n = 8)	P-value^b
Sex (female:male)	13:11	4:4	4:4	5:3	0.84
Body weight (kg)	3.0 (2.5–3.7)	2.9 (2.2–4.2)	2.9 (2.5–4.2)	3.3 (2.6–3.6)	0.76
Age (years)	0.8 (0.4–2.0)	0.6 (0.4–2.4)	0.8 (0.6–1.0)	1.8 (0.5–2.2)	0.61
Temperament score^c	1 (1–2)	1.0 (1.0–2.0)	1.5 (1.0–2.0)	1.5 (1.0–2.0)	0.89
HR (beats/minute)	180 (167–213)	190 (171–209)	177 (167–208)	193 (157–222)	0.96
RR (breaths/minute)	40 (35–48)	38 (32–50)	40 (36–47)	39 (35–46)	0.77
Rectal temperature (°C)	38.5 (38.1–39.0)	38.5 (38.1–38.9)	38.4 (37.9–38.8)	38.7 (38.2–39)	0.56
MAP (mmHg)	103 (87–121)	112 (87–125)	104 (92–140)	93 (83–121)	0.72

^a Data is expressed as median (IQR) except for sex which is expressed as a ratio.

^b Significance of difference between groups.

^c Temperament score: 1 = quiet, 2 = anxious, 3 = nervous, 4 = aggressive.

HR = heart rate; MAP = mean arterial pressure; RR = respiratory rate.

Figure 2. Mean (SE) thickness of the splenic head (a, transverse plane), body (b, sagittal plane) and tail (c, transverse plane) prior to (T0) and 10 (T10), 20 (T20) and 30 (T30) minutes following IM administration of 0.05 mg/kg acepromazine (ACE), 3 mg/kg alfaxalone (ALF) or 10 μg/kg dexmedetomidine (DEX), each in combination with 0.5 mg/kg morphine in cats (n = 8 per group). Asterisks indicate statistical significance compared to T0: *p < 0.05; **p < 0.01; ***p < 0.001.

Table 2. Mean (SE) thickness (mm) of the splenic head (transverse plane), body (sagittal plane) and tail (transverse plane) prior to (0 minutes) and 10, 20 and 30 minutes following IM administration of 0.05 mg/kg acepromazine (ACE), 3 mg/kg alfaxalone (ALF) or 10 μg/kg dexmedetomidine (DEX), in combination with 0.5 mg/kg morphine in cats (n = 8 per group).

	Time (minutes) following drug administration^a
	T0	T10	T20	T30
ACE
Head	8.0 (1.8)	9.03 (2.1)	9.38 (2.2)**	9.29 (1.8)***
Body	8.9 (2.1)	9.8 (2.0)*	10.5 (2.3)***	10.5 (2.0)**
Tail	8.4 (2.5)	9.3 (2.2)	9.9 (2.4)*	10.0 (2.2)**
ALF
Head	7.8 (1.2)	8.9 (1.2)*	8.9 (1.2)*	9.2 (1.0)**
Body	8.8 (1.0)	10.1 (1.5)**	10.0 (1.8)	10.3 (1.7)*
Tail	8.3 (1.4)	9.4 (1.1)*	9.1 (1.1)	9.3 (1.3)
DEX
Head	7.5 (1.2)	7.4 (0.9)	7.7 (0.8)	7.8 (1.0)
Body	8.6 (1.2)	8.7 (1.3)	9.0 (0.8)	8.9 (0.6)
Tail	8.0 (1.1)	7.9 (1.2)	8.2 (1.0)	8.2 (1.0)

^a Asterisks indicate statistical significance compared to T0: *p < 0.05; **p < 0.01; ***p < 0.001.

Figure 3. Mean (± SE) arterial pressure prior to (T0) and 10 (T10), 20 (T20) and 30 (T30) minutes following IM administration of 0.05 mg/kg acepromazine (ACE), 3 mg/kg alfaxalone (ALF) or 10 μg/kg dexmedetomidine (DEX), each in combination with 0.5 mg/kg morphine in cats (n = 8 per group). Statistically significant compared to DEX: *p < 0.05; **p < 0.01; ***p < 0.001.

Table 3. Mean (SE) heart rate (HR), respiratory rate (RR) and temperature, and median (IQR) sedation scores prior to (0 minutes) and 10, 20 and 30 minutes following IM administration of 0.05 mg/kg acepromazine (ACE), 3 mg/kg alfaxalone (ALF) or 10 μg/kg dexmedetomidine (DEX), each in combination with 0.5 mg/kg morphine, in cats (n = 8 per group).

	Time (minutes) following drug administration^a
	0	10	20	30
HR (beats/minute)
ACE	187 (30)	199 (16)	190 (19)	194 (29)
ALF	184 (23)	176 (34)	163 (33)	152 (37)
DEX	188 (37)	109 (34)	105 (25)	107 (22)
RR (breaths/minute)
ACE	42 (12)	35 (9)	35 (11)	33 (8)
ALF	42 (7)	38 (5)	33 (6)	29 (7)
DEX	39 (6)	36 (7)	31 (5)	31 (4)
Temperature (°C)
ACE	38.6 (0.6)	38.4 (0.6)	38.4 (0.4)	38.3 (0.3)
ALF	38.4 (0.5)	38.3 (0.3)	38.0 (0.5)	37.8 (0.6)
DEX	38.6 (0.4)	38.5 (0.5)	38.3 (0.5)	38.1 (0.5)
Sedation score
ACE	–	4 (3.25–4.75)	5 (4.25–5.75)	6 (5.25–5.75)**
ALF	–	10 (7.5–10)	8 (7.25–10)	6.5 (6–7)**
DEX	–	10 (10–10)	10 (10–10)	9.5 (8–10)

^a Asterisks indicate statistically significant difference in sedation score within treatment group and over time: *p < 0.05; **p < 0.01; ***p < 0.001.