Document: Invite

Comments:

BLS-13-v1

1 RECOVER 2.0 Worksheet

2 QUESTION ID: BLS-13

3 PICO Question:
In cats and dogs in CPA (P), does providing ventilation with other inspiratory times and tidal volumes (I), compared with with a 1-second inspiratory time and tidal volume of about 10 mL/kg (C), improve ... (O)?

4 Outcomes:
Favorable neurologic outcome, PaCO2, Oxygenation, Surrogate marker(s) of perfusion, Survival to discharge, ROSC

5 Prioritized Outcomes (1= most critical; final number = least important):

6 Favorable neurologic outcome
7 Survival to discharge
8 ROSC
9 PaCO2
10 Oxygenation
11 Surrogate markers of perfusion

12 Domain chairs: Steve Epstein, Kate Hopper; final edit by Jamie Burkitt

13 Evidence evaluators: Heike Botha, Guillaume Hoareau

14 Conflicts of interest: None reported

15 Search strategy: See attached document

16 Evidence Review:

17 Study Design

18 Reduced Quality Factors

19 0 = no serious, - = serious,

20 - - = very serious

21 Positive Quality Factors

22 0 = none, + = one, ++ = multiple

23 Dichotomous Outcome Summary

24 Non-Dichotomous Outcome Summary

25 Brief description

26 Overall Quality

27 High, moderate, low,
very low, none

28 No of studies

29 Study Type

30 RoB

31 Indirectness

32 Imprecision

33 Inconsistency

34 Large Effect

35 Dose-Response

36 Confounder

37 # Intervention with Outcome

38 # Control with Outcome

39 RR (95% CI)

40 Outcome: Favorable Neurological Outcome

41 1

42 EX

43 0

44 - -

45 -

46 0

47 0

48 0

49 0

50 One experimental swine study found no difference in neurological outcome at 24 hrs between a TV of 10ml/kg at 10pbm vs a TV of 20 ml/kg at 35 bpm (no I-time described)

51 very low

52 Outcome: Survival to discharge

53 1

54 EX

55 0

56 - -

57 -

58 0

59 0

60 0

61 0

62 One experimental swine study found no difference in neurological outcome at 24 hrs between a TV of 10ml/kg at 10pbm vs a TV of 20 ml/kg at 35 bpm (no I-time described)

63 very low

64 Outcome: ROSC
65 3	66 EX	67 0	68 - -	69 -	70 0	71 0	72 0	73 0	74 Three experimental swine study found no difference regardless of TV evaluated	75 very low
76 Outcome: PaCO2
77 3	78 EX	79 0	80 - -	81 -	82 0	83 0	84 0	85 0	86 Three experimental swine studies found no difference in PaCO2 regardless of TV evaluated	87 very low

88 Outcome: Oxygenation

89 3

90 EX

91 0

92 - -

93 -

94 0

95 0

96 0

97 0

98 One experimental swine study found PaO2 was higher with 10mlkg TV (~17bpm) vs 7ml/kg TV (10 bpm). The remaining two studies found no difference

99 very low

100 Outcome: Surrogate markers of perfusion

101 3

102 EX

103 0

104 - -

105 -

106 0

107 0

108 0

109 0

110 Three experimental swine study found no difference regardless of TV evaluated

111 very low

112 PICO Question Summary

113 Introduction

114 The optimal tidal volume and inspiratory time during ventilation in CPR would generate an appropriate PaCO2 and oxygenation while minimizing the negative cardiovascular effects of positive pressure ventilation. The current human guidelines for CPR generally recommend a tidal volume of 6 - 7 mL/kg (up to 10 mL/kg in some circumstances) and an inspiratory time of 1 second.1 The previous veterinary guidelines recommend a tidal volume of 10 mL/kg and an inspiratory time of 1 second.2 These recommendations were based on a limited body of evidence and equipoise remains.

115 Consensus on science

116 Outcome 1: Favorable neurologic outcome

117 For the most critical outcome of favorable neurologic outcome, we identified 1 experimental VF study in swine that addresses the PICO question (very low quality of evidence downgraded for very serious indirectness and serious imprecision).3 This study found no difference in neurological outcome at 24 hours when comparing a tidal volume (TV) of 10mL/kg at 10 breaths per minute (bpm) to a TV of 20 mL/kg at 35 bpm; inspiratory time (I-time) was not described.3

118 Outcome 2: Survival to discharge

119 For the next critical outcome of Survival to discharge, we identified 1 experimental VF study in swine that addresses the PICO question (very low quality of evidence downgraded for very serious indirectness and serious imprecision).3 This study found no difference in survival at 24 hours when comparing a TV of 10mL/kg at 10 bpm to a TV of 20 mL/kg at 35 bpm; I-time was not described.3

120 Outcome 3: ROSC

121 For the next critical outcome of ROSC, we identified 3 experimental VF studies in swine that address the PICO question (very low quality of evidence downgraded for very serious indirectness and serious imprecision). 3–5 One study compares a TV of 10 mL/kg at 10 bpm to a TV of 20 mL/kg at 35 bpm (I-time not described) 3; 1 study compares a TV of 10 mL/kg at baseline RR (~17 bpm) to a TV of 7 mL/kg at 10 bpm, both with a 2-second I-timeC; and the final study compares a TV of 8-9 mL/kg at 10 bpm to a TV of 2-3 mL/kg at 50 bpm (I-time not described)5. No study found a difference in ROSC between respective treatment groups. 3–5

122 Outcome 4: PaCO2

123 For the important outcome of PaCO2, we identified 3 experimental VF studies in swine that address the PICO question (very low quality of evidence downgraded for very serious indirectness and serious imprecision). 3–5 One study compares a TV of 10 mL/kg at 10 bpm to a TV of 20 mL/kg at 35 bpm (I-time not described)3; 1 study compares a TV of 10 mL/kg at baseline RR (~17 bpm) to a TV of 7 mL/kg at 10 bpm, both with a 2-second I-time4; and the final study compares a TV of 8-9 mL/kg at 10 bpm to a TV of 2-3 mL/kg at 50 bpm (I-time not described) 5. No study found a difference in PaCO2 between respective treatment groups. 3–5

124 Outcome 5: Oxygenation

125 For the important outcome of oxygenation, we identified 3 experimental VF studies in swine that address the PICO question (very low quality of evidence downgraded for very serious indirectness and serious imprecision). 3–5 One study found PaO2 was higher with a 10 mL/kg TV delivered at a baseline RR (~ 17 bpm) vs a 7 mL/kg TV at 10 bpm, both with 2-second I-times.4 The remaining 2 studies found no difference in PaO2 when comparing a TV of 10 mL/kg at 10 bpm to a TV of 20 mL/kg at 35 bpm (I-time not described) 3 or a TV of 8-9 mL/kg at 10 bpm to a TV of 2-3 mL/kg at 50 bpm (I-time not described).5

126 Outcome 6: Surrogate markers of perfusion

127 For the important outcome of Surrogate markers of perfusion, we identified 3 experimental VF studies in swine that address the PICO question (very low quality of evidence downgraded for very serious indirectness and serious imprecision).3–5 One study compares a TV of 10 mL/kg at 10 bpm to a TV of 20 mL/kg at 35 bpm (I-time not described)3; 1 study compares a TV of 10 mL/kg at baseline RR (~17 bpm) to a TV of 7 mL/kg at 10 bpm, both with a 2-second I-time4; and the final study compares a TV of 8-9 mL/kg at 10 bpm to a TV of 2-3 mL/kg at 50 bpm (I-time not described)5. No study found a difference in hemodynamic parameters between respective treatment groups.3–5

128 Treatment recommendation

129 We recommend administering positive pressure ventilation at a tidal volume of 10 mL/kg and a 1-second inspiratory time during CPR in intubated dogs and cats.(strong recommendation, very low quality of evidence)

130 Justification of treatment recommendation

131 The evidence identified found a tidal volume of ~10 mL/kg had similar outcomes to several other tidal volumes evaluated. Overall, this treatment recommendation is based on a very low level of evidence that failed to identify a superior option. Inspiratory time is very poorly evaluated in the literature and the treatment recommendation is based on common clinical practice and previous consensus statements.

132 Knowledge gaps

133 Further studies are necessary to determine the ideal inspiratory time and tidal volume in intubated dogs and cats during CPA.

134 Limited studies exist investigating varied tidal volumes; however, inspiratory time is frequently not mentioned and no studies evaluating varying inspiratory times were found.

135 References:

136 1. Panchal AR, Bartos JA, Cabañas JG, et al. Part 3: Adult Basic and Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2020;142(16_suppl_2):S366-S468.

137 2. Fletcher DJ, Boller M, Brainard BM, et al. RECOVER evidence and knowledge gap analysis on veterinary CPR. Part 7: Clinical guidelines: RECOVER clinical guidelines. J Vet Emerg Crit Care. 2012;22(s1):S102-S131.

138 3. Hayes MM, Ewy GA, Anavy ND, et al. Continuous passive oxygen insufflation results in a similar outcome to positive pressure ventilation in a swine model of out-of-hospital ventricular fibrillation. Resuscitation. 2007;74(2):357-365.

139 4. Tan D, Sun J, Geng P, et al. Duration of cardiac arrest requires different ventilation volumes during cardiopulmonary resuscitation in a pig model. J Clin Monit Comput. Published online 2019.

140 5. Ruemmler R, Ziebart A, Moellmann C, et al. Ultra-low tidal volume ventilation-A novel and effective ventilation strategy during experimental cardiopulmonary resuscitation. Resuscitation. 2018;132:56-62.

141 Supplemental:

142 258: Hayes 2007 – 36 Swine (12/group: 10mL/kg at 10bpm, 20 mL/kg at 35 bpm, no IPPV groups), VF, 8-minute downtime prior to any intervention

143 264: Tan 2019 – 32 swine (16 4-min VF downtime, 16 8-min VF downtime), randomized to 7mL/kg at 10bpm v 10mL/kg at baseline RR – appx 17 bpm - (all 2-sec I-time).

144 276: Ruemmler 2018 – 30 swine in 4-minute VF downtime, randomized (10/ group: 2-3 mL/kg at 50 bpm v 8-9mL/kg at 10 bpm vs no IPPV)

DMU Timestamp: July 13, 2023 21:18