16 Study Design

17 Reduced Quality Factors

18 0 = no serious, - = serious,

19 - - = very serious

20 Positive Quality Factors

21 0 = none, + = one, ++ = multiple

22 Dichotomous Outcome Summary

23 Non-Dichotomous Outcome Summary

24 Brief description

25 Overall Quality

26 High, moderate, low,
very low, none

27 No of studies

28 Study Type

29 RoB

30 Indirectness

31 Imprecision

32 Inconsistency

33 Large Effect

34 Dose-Response

35 Confounder

36 # Intervention with Outcome

37 # Control with Outcome

38 RR (95% CI)

39 Outcome: Favorable neurologic outcome, Survival to discharge, ROSC

40 0

41 N/A

42 Outcome: Surrogate markers of perfusion

43 2

44 EX

45 0

46 - -

47 0

48 0

49 0

50 0

51 0

52 Two studies using a human infant manikin model found a circumferential, 2 thumb technique generates higher pressure in a simulated arterial system compared to a 2-finger technique

53 Very low

55 Introduction

56 The optimal chest compression technique in cats and small dogs is unknown. Lateral chest compression can be achieved in these small sized animals with 2-finger, 1-handed, or 2-handed techniques. Alternatively, 2 hands can be used to encircle the chest, which allows the rescuer to squeeze the thorax during compressions. The current pediatric human guidelines state there is insufficient evidence to make a recommendation regarding compression technique and suggest either a 1-handed or 2-handed technique can be used.1

57 Consensus on science

58 For the most critical outcomes of FNO, Survival to discharge, and ROSC we identified no studies addressing the PICO question.

59 Outcome 4: Surrogate markers of perfusion

60 For the important outcome of surrogate markers of perfusion, we found 2 manikin-based experimental studies (very low level of evidence, downgraded for very serious indirectness).2,3 These 2 studies found that a circumferential, 2-thumb (i.e., 2-handed) technique generates higher pressure in a simulated arterial system compared to a 2-finger technique.2,3

61 For the less important outcome of complications, we identified no studies addressing this PICO question.

62 Treatment recommendation

63 We recommend that chest compressions in cats and small dogs be performed using 1 of the following 3 methods, based on a combination of compressor preference and real-time markers of perfusion (e.g., EtCO2, direct blood pressure monitoring):

64 a) using a circumferential 2-thumb chest compression technique with the animal in lateral recumbency and both of the thumbs directly over the heart.(strong recommendation, very low quality of evidence)

65 b) using a 1-handed technique with the dominant hand wrapped around the sternum at the level of the heart performing compressions between the flat portion of the fingers and the flat portion of the thumb.(strong recommendation, expert opinion)

66 c) using a 1-handed technique with heel of the dominant hand compressing 1/3 to 1/2 the chest width over the area of the heart with the animal in lateral recumbency while the non-dominant hand supports the dorsal thorax.(strong recommendation, expert opinion)

67 Justification of treatment recommendation

68 Given there is very little evidence to inform a recommendation regarding ideal compression technique in cats and small dogs, the committee believes it is appropriate to provide a variety of options, integrating recommendations from multiple sources. The circumferential 2-thumb technique is recommended based on findings that suggest it may be superior in human infants while lateral recumbency is suggested based on chest conformation. The limited available evidence suggests that a circumferential 2-thumb chest compression technique may produce higher intrathoracic pressures than a 2-finger compression technique in human infants. This may translate to improvement in critical outcomes and supports methods (a) and (b), above. Additionally, anecdotal experience suggests that compression depth appears adequate in these animals when high-quality, 1-handed chest compressions are administered in lateral recumbency in cats and small dogs, which supports method (c), above.

69 Knowledge gaps

70 There are no studies of cats or small dogs or in animal models in lateral recumbency evaluating different chest compression techniques for any outcome of interest. Further studies of chest compression technique in cats and small dogs are needed.