CPR: Let’s discuss the nitty-gritty and the how and when. I know you want the meat and potatoes of CPR, as outlined in the current Reassessment Campaign on Veterinary Resuscitation (RECOVER) CPR Guidelines, and I promise that if you continue reading, I will highlight key updates to basic life support (BLS) and advanced life support (ALS) CPR. However, where did the evidence come from to establish and update these guidelines? How do the creators of these guidelines (and others) evaluate the strength of the evidence, and what level of certainty do they have with their recommendations? Evaluating the evidence To review how the RECOVER Initiative established its guidelines, we need to understand how evidence is evaluated and what goes into developing guidelines. Sometimes, sufficient comparable evidence does not exist to conduct systematic reviews and meta-analyses (the highest levels of evidence) for all outcomes evaluated. However, researchers can use the PICO question format to assess various outcomes, compile the available evidence, and then make informed decisions and develop consensus guidance for all. PICO Researchers will ask PICO questions about a topic. This means they will look to:1–4 P: Define the population I: Identify the intervention (treatment, diagnostic, surgical procedure, etc.) C: Provide comparisons (e.g., control and testing groups; treated/untreated; live/die) O: Prioritize outcomes of interest Developed by the National Library of Medicine, PICO enables an evidence-based search of the literature by asking questions about study design, population, intervention, and comparison to select studies for assessment, identification, and more.5 When conducting evidence syntheses (e.g., in essence, performing a systematic review), the PICO method helps frame questions to evaluate the literature, specifically focusing on populations, interventions, comparison groups, and outcomes of interest.2-4 Including systematic reviews in the process of developing guidelines helps ensure “concordance between quality of evidence and strength of recommendations,”6 a key principle of evidence-based medicine. The RECOVER team included a systematic review in their guideline development process and applied “best practice” tools, including the PICO framework. In practice Here are examples of PICO questions the RECOVER Initiative asked: The use of CO2 detection for endotracheal intubation success “In cats and dogs in respiratory or cardiac arrest (P) following attempted endotracheal intubation, does CO2 detection (capnometer or colorimetric CO2 detector) (I) compared to standard clinical assessment (laryngeal visualization, cervical palpation) (C) affect survival to discharge, ROSC, correct intubation, time to start CPR, or complications (O)?”3,4 Determining the “optimal ETco2 target during CPR”3,4 In cats and dogs with CPA (P), does achieving any other specific ETco2 during CPR (I), compared to achieving ETco2 of ≥15 mm Hg (C), improve favorable neurologic outcome, survival to discharge, or ROSC (O)?”3,4 Note: ROSC (return of spontaneous circulation)3,4 GRADE In addition to evaluating the various populations, interventions, and outcomes, we need to assess the level of certainty in the available evidence for each outcome evaluated. We do so by using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). This uses a systematic, transparent approach to critically appraise evidence, ideally from systematic reviews but also from any available evidence. It takes into account factors, including:1,7 Evidence certainty Inconsistencies Risks of bias Imprecision Publication biases Indirectness GRADE provides a framework for evaluating the certainty (or quality) of evidence, rated as very low, low, moderate, or high.8,9 We need a means to display our confidence level in the results for a given outcome. Moreover, we hope our evaluation approximates the true effect of the intervention (e.g., hand position during CPR and the success of chest compressions).8 Thus, GRADE indicates the assurance that the truth lies on one side of a designated threshold or within a particular range.7 The 2024 RECOVER CPR Guidelines do not recommend assessing pulse in an apneic, unresponsive patient when determining the presence of cardiopulmonary arrest (CPA).10 The RECOVER Initiative used the GRADE scheme to review each study for: “(1) determining which of the outcomes of interest were directly addressed in the study, (2) identifying the study type, (3) answering questions focused on assessing the risk of bias (RoB) in the study, (4) evaluating the degree of indirectness in the study related to the PICO question, (5) determining the degree of imprecision in the study results, (6) identifying any aspects of the study that might increase the relative strength of the study results, and (7) writing a brief statement describing the treatment recommendation(s) related to the PICO question that could be made based on the results of the study.”3 Indirectness can affect the strength of the evidence. Indirectness refers to the applicability of the evidence to the PICO of interest. Patient populations and interventions may vary across studies, making comparisons challenging.4,10,11 A veterinary technician assesses a canine patient for CPA and starts contractions while awaiting a step stool. Photo courtesy Dr. Erica Tramuta-Drobnis Guideline development Once a topic has been evaluated using PICO questions and the GRADE approach has assessed the certainty of the evidence, a group, such as the RECOVER Initiative, can develop evidence-to-decision-based guidelines.7 Considerations that need to go into the guideline creation, which were utilized by the RECOVER Initiative, include:8 Is the problem (e.g., performing CPR effectively) a priority? What is the magnitude of the expected benefits and adverse effects? What is the overarching level of certainty for the given evidence? Strong recommendations, ideally, should be based on the highest level of available evidence (easier in human medicine due to the plethora of human research) What is the significance of the crucial outcomes, and is there considerable ambiguity or variability in their valuation? Do the benefits and desired effects balance against any adverse events or harms? What are the resources/costs associated with an intervention? How acceptable will the recommendations for a specific intervention be? How feasible are the recommendations to implement? Sometimes, there is not enough high-level evidence to achieve high certainty; low-level evidence weakens the strength of recommendations, leading guideline developers to rely on expert opinion to reach consensus.6 Some of the RECOVER statements and guidelines are, in fact, this way. Why? Because in veterinary medicine, we simply do not have enough studies comparing the same outcomes with similar methodologies, sufficient sample sizes, comparable populations, or equivalent outcome measurements to permit anything else. Still, those who developed the RECOVER guidelines used the most up-to-date evidence available and based their recommendations on it.3,4,8,12 A crash cart with CPR tools (ALS medications, airway supplies, and more) is readily available for any CPA.Photo courtesy Dr. Erica Tramuta-Drobnis RECOVER CPR Guidelines for small animals Current CPR guidelines were developed using an evidence-based approach that involved systematic reviews and consideration of evidence relevant to 135 PICO questions. The evidence was evaluated by more than 200 professionals, including librarians and veterinarians from specialty and general practices, as well as academia. They used findings from their PICO questions to develop recommendations on small-animal ALS and BLS CPR protocols, neonatal resuscitation, large-animal CPR, and first aid. They took steps to eliminate study bias and improve the repeatability of their evaluation results. They identified numerous gaps in the information and research on resuscitation in veterinary medicine and proposed future research priorities. Ultimately, the RECOVER Initiative was a collaborative undertaking that compiled the gathered information and developed cohesive, consensus- and evidence-based guidelines for practicing clinicians. Previous guidelines lacked such rigorous, detailed directives and relied more on consensus-based (collective expert opinion) practices than on evidence. Still, consensus-based recommendations were sometimes necessary to address gaps in the literature, even for the current guidelines.3 RECOVER BLS recommendations Current BLS recommendations generally state that cats and dogs go into cardiopulmonary arrest (CPA) due to primary respiratory arrest. Breathing stops, reducing oxygen to the heart, and then the heart stops. Thus, recognition of the cessation of breathing is crucial to ensure that CPR is initiated early and vital functions are preserved.12–14 The general BLS algorithm has us first check an unresponsive patient, then call for help, and then shake/shout to see if there is any response; if none, check for breathing. If there is no breathing and only one rescuer is present, we check the airway (clearing any obstructions with suction or gauze pads using a rostrocaudal or lateral approach, being careful not to push anything deeper) before starting single-rescuer CPR. If we have two people, one starts compressions, and the other secures the airway (ideally via intubation, if feasible).12–14 You will notice there is no pulse check. Because cessation of breathing indicates CPA in our animals, we don’t need to waste time searching for that pulse. Instead, we want to prioritize initiation of CPR to minimize ischemia and ensure oxygen delivery to tissues. We do this in two ways:12 Generating blood flow with external chest compressions or internal cardiac massage Getting oxygen to the arterial blood (oxygenation) and removing CO2 from the venous system (ventilation) BLS is a two-minute uninterrupted cycle:13,14 Perform chest compressions for two minutes: 100-120 BPM Compression depth target is 1/3 to 1/2 the width of the animal’s chest in the lateral and 1/4 the depth in dorsal recumbency10,11 Ventilate for the patient every six seconds (10 BPM) Pause for <10 seconds to check for a pulse. If ALS monitoring has been established, assess whether the ECG shows a shockable rhythm; then immediately restart another BLS cycle. For compressions:12,13 Medium and large breed dogs utilize a two-handed approach, ensuring to: Stand/kneel behind the spine when in lateral or on either side of the thorax in dorsal Shoulders remain directly over the hands Elbows remain locked One hand rests on top of the other, stacking the heels of the hands Engage core muscles when bending at the waist for adequate compressions For small dogs (< 7 kg) and cats, we can use:12 One-handed approach with the thumb flat against the palm Circumferential approach, where both thumbs are placed over the ventricles One-arm approach with the hand’s heel/palm placed over the heart Do not use the two-handed approach in small dogs/cats, or you risk complications. RECOVER ALS recommendations Once BLS CPR has been initiated, if more people become available, then ALS can be established concurrently without interrupting the two-minute BLS cycles. ALS recommendations, if feasible, focus on:12 Monitoring the ECG and ETC02 (targeting 18+ mmHg) Ensuring IV access Administering reversal agents for any opioids/benzodiazepines/alpha-2-agonists on board Key updates and emphases in the current ALS recommendations include:12,15 High-dose epinephrine is no longer recommended. Instead, administer IV or IO epinephrine every other cycle at 0.01 mg/kg, unless a shockable rhythm is present. If a rhythm is shockable (e.g., V-Fib/V-Tach) and you have access to a defibrillator, shock at the standard dose, and then immediately restart another full 2-minute BLS cycle. If no response, double that dose. IV over IO access is the preferred drug route. Atropine is only used as a single dose and as early as possible in non-shockable CPA. In patients with a shockable rhythm that fail to respond to defibrillation, continue to defibrillate but also consider administering vasopressin, esmolol, or lidocaine (dogs) or amiodarone (cats). CPR Guidelines and the evidence Refreshing your skills annually is always a good idea; however, if you have not yet taken the RECOVER BLS and ALS courses, I highly recommend them for all team members.13,16 I know, though the evidence may not matter to some, it should, because it improves the chances of a successful CPR outcome. However, knowing that the guidelines you follow were developed through a systematic review using globally recognized, pre-validated PICO and GRADE frameworks helps the user appreciate that they were created in accordance with the available evidence to date. Although we do not have high-grade evidence for all PICO questions of interest, these recommendations reflect the information available to us, based on the search parameters the RECOVER Initiative chose. Thus, the guidelines represent the best consensus- and evidence-based steps to ensure successful CPR. Recognize that even though experts evaluated the evidence, evidence is lacking in numerous areas; thus, recommendations may be updated upon review of new research. Hopefully, the identified research gaps will be addressed and new information will emerge in the future. Understanding how guidelines come about, the process used to synthesize the evidence, if the recommendations are made in accordance with the quality of evidence (GRADE), and how PICO questions help to both formulate research questions and also to synthesize and gather evidence, helps one to appreciate how evidence plays a role in the clinical decisions we make and our confidence in the recommendations we use. Ultimately, these guidelines can impact patient outcomes. Prompt recognition of a CPA and initiation of BLS care are paramount for maintaining blood and oxygen flow to vital organs and improving outcomes. Erica Tramuta-Drobnis, VMD, CPH, is the CEO and founder of ELTD One Health Consulting, LLC. She works as a public health professional, an emergency veterinarian, a freelance writer, a consultant, and a researcher. Dr. Tramuta-Drobnis is passionate about One Health issues and is a strong advocate of evidence-based veterinary medicine. She is the president-elect of the Evidence-Based Veterinary Medical Association (EBVMA). References Al Duhailib Z, Granholm A, Alhazzani W, Oczkowski S, Belley-Cote E, Møller MH. GRADE pearls and pitfalls—Part 1: Systematic reviews and meta-analyses. Acta Anaesthesiol Scand. 2024;68(5):584-592. doi:10.1111/aas.14386 Eriksen MB, Frandsen TF. The impact of patient, intervention, comparison, outcome (PICO) as a search strategy tool on literature search quality: a systematic review. J Med Libr Assoc JMLA. 2018;106(4):420-431. doi:10.5195/jmla.2018.345 Fletcher D, Boller M, Burkitt Creedon J, et al. 2024 RECOVER Guidelines: Methods, evidence identification, evaluation, and consensus process for development of treatment recommendations. J Vet Emerg Crit Care. 2024;34:3-15. doi:10.1111/vec.13388 Brainard BM, Lane SL, Burkitt-Creedon JM, et al. 2024 RECOVER Guidelines: Monitoring. Evidence and knowledge gap analysis with treatment recommendations for small animal CPR. J Vet Emerg Crit Care. 2024;34(S1):76-103. doi:10.1111/vec.13390 Brown D. A Review of the PubMed PICO Tool: Using Evidence-Based Practice in Health Education. Health Promot Pract. 2020;21(4):496-498. doi:10.1177/1524839919893361 Yao L, Ahmed MM, Guyatt GH, et al. Discordant and inappropriate discordant recommendations in consensus and evidence based guidelines: empirical analysis. BMJ. 2021;375:e066045. doi:10.1136/bmj-2021-066045 Hultcrantz M, Rind D, Akl EA, et al. The GRADE Working Group clarifies the construct of certainty of evidence. J Clin Epidemiol. 2017;87:4-13. doi:10.1016/j.jclinepi.2017.05.006 Granholm A, Al Duhailib Z, Alhazzani W, Oczkowski S, Belley-Cote E, Møller MH. GRADE pearls and pitfalls—Part 2: Clinical practice guidelines. Acta Anaesthesiol Scand. 2024;68(5):593-600. doi:10.1111/aas.14384 Brignardello-Petersen R, Guyatt GH. Assessing the certainty of the evidence in systematic reviews: importance, process, and use. Am J Epidemiol. 2024;194(6):1681-1686. doi:10.1093/aje/kwae332 Guyatt G, Oxman AD, Akl EA, et al. GRADE guidelines: 1. Introduction—GRADE evidence profiles and summary of findings tables. J Clin Epidemiol. 2011;64(4):383-394. doi:10.1016/j.jclinepi.2010.04.026 Guyatt GH, Oxman AD, Vist GE, et al. GRADE: an emerging consensus on rating quality of evidence and strength of recommendations. BMJ. 2008;336(7650):924-926. doi:10.1136/bmj.39489.470347.AD Burkitt-Creedon JM, Boller M, Fletcher DJ, et al. 2024 RECOVER Guidelines: Updated treatment recommendations for CPR in dogs and cats. J Vet Emerg Crit Care. 2024;34(S1):104-123. doi:10.1111/vec.13391 RECOVER Initiative. RECOVER CPR - BLS (Veterinarian). RECOVER Initiatve; 2024. https://therecoverinitiative.docebosaas.com/learn Hopper K, Epstein SE, Burkitt-Creedon JM, et al. 2024 RECOVER Guidelines: Basic Life Support. Evidence and knowledge gap analysis with treatment recommendations for small animal CPR. J Vet Emerg Crit Care. 2024;34(S1):16-43. doi:10.1111/vec.13387 Wolf J, Buckley GJ, Rozanski EA, et al. 2024 RECOVER Guidelines: Advanced Life Support. Evidence and knowledge gap analysis with treatment recommendations for small animal CPR. J Vet Emerg Crit Care. 2024;34 Suppl 1:44-75. doi:10.1111/vec.13389 RECOVER Initiative. RECOVER CPR - ALS (Veterinarian). RECOVER Initiatve; 2024. Accessed May 20, 2026. https://therecoverinitiative.docebosaas.com/learn
