ABSTRACT
The International Liaison Committee on Resuscitation has initiated a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation science. This is the third annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. It addresses the most recent published resuscitation evidence reviewed by International Liaison Committee on Resuscitation Task Force science experts. This summary addresses the role of cardiac arrest centers and dispatcher-assisted cardiopulmonary resuscitation, the role of extracorporeal cardiopulmonary resuscitation in adults and children, vasopressors in adults, advanced airway interventions in adults and children, targeted temperature management in children after cardiac arrest, initial oxygen concentration during resuscitation of newborns, and interventions for presyncope by first aid providers. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the certainty of the evidence on the basis of the Grading of Recommendations, Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence to Decision Framework Highlights sections. The task forces also listed priority knowledge gaps for further research.
Subject(s)
Cardiopulmonary Resuscitation/standards , Emergency Medical Services/standards , Emergency Treatment , Hypothermia, Induced/standards , Child , Emergency Service, Hospital/standards , Emergency Treatment/standards , Humans , Out-of-Hospital Cardiac Arrest/therapyABSTRACT
We previously reported in HEK 293T cells that silencing the mitochondrial peptidyl prolyl isomerase cyclophilin-D (Cyp-D) reduces Vo2. We now report that in vivo Cyp-D ablation using constitutive Cyp-D knockout (KO) mice also reduces Vo2 both at rest (â¼15%) and during treadmill exercise (â¼12%). Yet, despite Vo2 reduction, these Cyp-D KO mice ran longer (1071 ± 77 vs. 785 ± 79 m; P = 0.002), for longer time (43 ± 3 vs. 34 ± 3 min; P = 0.004), and at higher speed (34 ± 1 vs. 29 ± 1 m/s; P ≤ 0.001), resulting in increased work (87 ± 6 vs. 58 ± 6 J; P ≤ 0.001). There were parallel reductions in carbon dioxide production, but of lesser magnitude, yielding a 2.3% increase in the respiratory exchange ratio consistent with increased glucose utilization as respiratory substrate. In addition, primary skeletal muscle cells of Cyp-D KO mice subjected to electrical stimulation exhibited higher glucose uptake (4.4 ± 0.55 vs. 2.6 ± 0.04 pmol/mg/min; P ≤ 0.001) with enhanced AMPK activation (0.58 ± 0.06 vs. 0.38 ± 0.03 pAMPK/ß-tubulin ratio; P ≤ 0.01) and TBC1 (Tre-2/USP6, BUB2, Cdc16) domain family, member 1 (TBC1D1) inactivation. Likewise, pharmacological activation of AMPK also increased glucose uptake (3.2 ± 0.3 vs. 2.3 ± 0.2 pmol/mg/min; P ≤ 0.001). Moreover, lactate and ATP levels were increased in these cells. Taken together, Cyp-D ablation triggered an adaptive response resulting in increased exercise capacity despite less oxygen utilization associated with increased glucose uptake and utilization involving AMPK-TBC1D1 signaling nexus.-Radhakrishnan, J., Baetiong, A., Kaufman, H., Huynh, M., Leschinsky, A., Fresquez, A., White, C., DiMario, J. X., Gazmuri, R. J. Improved exercise capacity in cyclophilin-D knockout mice associated with enhanced oxygen utilization efficiency and augmented glucose uptake via AMPK-TBC1D1 signaling nexus.
Subject(s)
AMP-Activated Protein Kinases/metabolism , GTPase-Activating Proteins/metabolism , Glucose/metabolism , Oxygen/metabolism , Peptidyl-Prolyl Isomerase F/metabolism , Signal Transduction/physiology , Animals , Biological Transport/physiology , Cell Line , Exercise Tolerance/physiology , Female , HEK293 Cells , Humans , Mice , Mice, Knockout , Muscle Fibers, Skeletal/metabolism , Muscle, Skeletal/metabolism , Physical Conditioning, Animal/physiologyABSTRACT
Cardiopulmonary resuscitation is a lifesaving technique for victims of sudden cardiac arrest. Despite advances in resuscitation science, basic life support remains a critical factor in determining outcomes. The American Heart Association recommendations for adult basic life support incorporate the most recently published evidence and serve as the basis for education and training for laypeople and healthcare providers who perform cardiopulmonary resuscitation.
Subject(s)
American Heart Association , Cardiopulmonary Resuscitation/standards , Emergency Medical Services/standards , Heart Arrest/therapy , Heart Massage/standards , Quality Indicators, Health Care/standards , Respiration, Artificial/standards , Cardiopulmonary Resuscitation/adverse effects , Cardiopulmonary Resuscitation/mortality , Consensus , Health Education/standards , Health Personnel/education , Health Personnel/standards , Heart Arrest/diagnosis , Heart Arrest/mortality , Heart Arrest/physiopathology , Heart Massage/adverse effects , Heart Massage/mortality , Humans , Respiration, Artificial/adverse effects , Respiration, Artificial/mortality , Risk Factors , Treatment Outcome , United StatesABSTRACT
Out-of-hospital sudden cardiac arrest is a major public health problem with an overall survival of less than 5%. Upon cardiac arrest, cessation of coronary blood flow rapidly leads to intense myocardial ischemia and activation of the sarcolemmal Na+-H+ exchanger isoform-1 (NHE-1). NHE-1 activation drives Na+ into cardiomyocytes in exchange for H+ with its exchange rate intensified upon reperfusion during the resuscitation effort. Na+ accumulates in the cytosol driving Ca2+ entry through the Na+-Ca2+ exchanger, eventually causing cytosolic and mitochondrial Ca2+ overload and worsening myocardial injury by compromising mitochondrial bioenergetic function. We have reported clinically relevant myocardial effects elicited by NHE-1 inhibitors given during resuscitation in animal models of ventricular fibrillation (VF). These effects include: (a) preservation of left ventricular distensibility enabling hemodynamically more effective chest compressions, (b) return of cardiac activity with greater electrical stability reducing post-resuscitation episodes of VF, (c) less post-resuscitation myocardial dysfunction, and (d) attenuation of adverse myocardial effects of epinephrine; all contributing to improved survival in animal models. Mechanistically, NHE-1 inhibition reduces adverse effects stemming from Na+-driven cytosolic and mitochondrial Ca2+ overload. We believe the preclinical work herein discussed provides a persuasive rationale for examining the potential role of NHE-1 inhibitors for cardiac resuscitation in humans.
Subject(s)
Heart Arrest/drug therapy , Myocardial Ischemia/genetics , Sodium-Hydrogen Exchangers/genetics , Ventricular Fibrillation/drug therapy , Calcium/metabolism , Calcium Signaling/drug effects , Calcium Signaling/genetics , Heart Arrest/genetics , Heart Arrest/pathology , Humans , Models, Animal , Myocardial Ischemia/drug therapy , Myocardial Ischemia/pathology , Myocardium/metabolism , Myocardium/pathology , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/pathology , Sarcolemma/metabolism , Sarcolemma/pathology , Sodium-Hydrogen Exchangers/antagonists & inhibitors , Sodium-Hydrogen Exchangers/metabolism , Ventricular Fibrillation/genetics , Ventricular Fibrillation/pathologyABSTRACT
The International Liaison Committee on Resuscitation has initiated a near-continuous review of cardiopulmonary resuscitation science that replaces the previous 5-year cyclic batch-and-queue approach process. This is the first of an annual series of International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations summary articles that will include the cardiopulmonary resuscitation science reviewed by the International Liaison Committee on Resuscitation in the previous year. The review this year includes 5 basic life support and 1 pediatric Consensuses on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. Each of these includes a summary of the science and its quality based on Grading of Recommendations, Assessment, Development, and Evaluation criteria and treatment recommendations. Insights into the deliberations of the International Liaison Committee on Resuscitation task force members are provided in Values and Preferences sections. Finally, the task force members have prioritized and listed the top 3 knowledge gaps for each population, intervention, comparator, and outcome question.
Subject(s)
Cardiology/standards , Cardiopulmonary Resuscitation/standards , Emergency Medical Services/standards , Emergency Medicine/standards , Evidence-Based Medicine/standards , Heart Arrest/therapy , Age Factors , Consensus , Heart Arrest/diagnosis , Heart Arrest/mortality , Humans , Out-of-Hospital Cardiac Arrest/diagnosis , Out-of-Hospital Cardiac Arrest/mortality , Out-of-Hospital Cardiac Arrest/therapy , Treatment OutcomeABSTRACT
A triad of circulatory collapse, right ventricular dilatation, and large alveolar dead space is proposed for the rapid diagnosis and treatment of massive pulmonary embolism. A 17year-old female on oral contraceptives collapsed at home becoming incoherent with shallow breathing. Paramedics initiated mechanical chest compression and transported the patient to our emergency department, arriving minimally responsive with undetectable blood pressure but having positive corneal reflexes and bradycardia with wide QRS. The trachea was intubated and goal-directed echocardiography revealed marked right ventricular dilatation with septal flattening. The arterial PCO2 was 40mmHg with an end-tidal PCO2 of 8mmHg, revealing a large alveolar dead space. Persistent hypotension, bradycardia, and fading alertness despite epinephrine and norepinephrine infusions prompted resumption of chest compression. Intravenous alteplase (10mg bolus over 10min followed by 90mg over 110min) begun 125min after collapse improved hemodynamic function within 10min allowing discontinuation of chest compression. Five and a half hours after starting alteplase, the patient was hemodynamically stable and had normal end-tidal PCO2. A CT-angiogram showed the pulmonary arteries free of emboli but a thrombus in the right common iliac vein. The patient recovered fully and was discharged home on warfarin 8days later. Based on this and other reports, we propose a triad of circulatory collapse, right ventricular dilatation, and large alveolar dead space for the rapid diagnosis and treatment of massive pulmonary embolism, with systemic fibrinolysis as the first-line intervention.
Subject(s)
Pulmonary Embolism/diagnosis , Respiratory Dead Space , Shock/diagnostic imaging , Ventricular Dysfunction, Right/diagnostic imaging , Adolescent , Computed Tomography Angiography , Dilatation , Echocardiography , Electrocardiography , Female , Fibrinolytic Agents/administration & dosage , Hemodynamics , Humans , Pulmonary Embolism/drug therapy , Tissue Plasminogen Activator/administration & dosage , WarfarinABSTRACT
This review comprises the most extensive literature search and evidence evaluation to date on the most important international BLS interventions, diagnostics, and prognostic factors for cardiac arrest victims. It reemphasizes that the critical lifesaving steps of BLS are (1) prevention, (2) immediate recognition and activation of the emergency response system, (3) early high-quality CPR, and (4) rapid defibrillation for shockable rhythms. Highlights in prevention indicate the rational and judicious deployment of search-and-rescue operations in drowning victims and the importance of education on opioid-associated emergencies. Other 2015 highlights in recognition and activation include the critical role of dispatcher recognition and dispatch-assisted chest compressions, which has been demonstrated in multiple international jurisdictions with consistent improvements in cardiac arrest survival. Similar to the 2010 ILCOR BLS treatment recommendations, the importance of high quality was reemphasized across all measures of CPR quality: rate, depth, recoil, and minimal chest compression pauses, with a universal understanding that we all should be providing chest compressions to all victims of cardiac arrest. This review continued to focus on the interface of BLS sequencing and ensuring high-quality CPR with other important BLS interventions, such as ventilation and defibrillation. In addition, this consensus statement highlights the importance of EMS systems, which employ bundles of care focusing on providing high-quality chest compressions while extricating the patient from the scene to the next level of care. Highlights in defibrillation indicate the global importance of increasing the number of sites with public-access defibrillation programs. Whereas the 2010 ILCOR Consensus on Science provided important direction for the "what" in resuscitation (ie, what to do), the 2015 consensus has begun with the GRADE methodology to provide direction for the quality of resuscitation. We hope that resuscitation councils and other stakeholders will be able to translate this body of knowledge of international consensus statements to build their own effective resuscitation guidelines.
Subject(s)
Cardiopulmonary Resuscitation/standards , Defibrillators , Electric Countershock/standards , Emergency Medical Services/standards , Heart Arrest/therapy , Adult , Age Factors , Analgesics, Opioid/adverse effects , Cardiopulmonary Resuscitation/methods , Child , Electric Countershock/methods , Emergencies , Emergency Medical Services/methods , Health Education , Heart Arrest/chemically induced , Heart Arrest/drug therapy , Heart Massage/methods , Heart Massage/standards , Humans , Naloxone/therapeutic use , Near Drowning/therapy , Observational Studies as Topic , Randomized Controlled Trials as Topic , Ventricular Fibrillation/therapyABSTRACT
Cyclophilin-D (Cyp-D) is a mitochondrial matrix peptidyl-prolyl isomerase. Because cyclophilins can regulate nuclear gene expression, we examined whether Cyp-D could regulate mitochondrial gene expression. We demonstrated in HEK 293T cells that transfected Cyp-D interacts with mitochondrial transcription factors B1 and B2 (TFB2M) but not with mitochondrial transcription factor A. We also demonstrated that Cyp-D interacts in vivo with TFB2M. Genetic silencing of Cyp-D and pharmacologic inhibition of Cyp-D markedly reduced mitochondrial transcription to 18 ± 5% (P < 0.05) and 24 ± 3% (P < 0.05) of respective controls. The level of interaction between Cyp-D and TFB2M correlated with the level of nascent mitochondrial RNA intensity (r = 0.896; P = 0.0156). Cyp-D silencing down-regulated mitochondrial transcripts initiated from the heavy strand promoter 2 [i.e., NADH dehydrogenase 1 (ND1) by 11-fold, P < 0.005; cytochrome oxidase 1 (COX1) by 4-fold, P < 0.001; and ATP synthase subunit 6 (ATP6) by 6.5-fold, P < 0.005); but not NADH dehydrogenase 6 (ND6)], which is initiated from the light strand promoter. Cyp-D silencing reduced mitochondrial membrane potential and cellular oxygen consumption (from 59 ± 5 to 34 ± 1 µmol oxygen/min/10(6) cells, P < 0.001); the latter without a statistically significant reversal after uncoupling electron transport from ATP synthesis, consistent with down-regulation of electron transport complexes. Accordingly, these studies provide novel evidence that Cyp-D could play a key role in regulating mitochondrial gene expression.
Subject(s)
Cyclophilins/metabolism , Genes, Mitochondrial , Cyclooxygenase 1/genetics , Cyclophilins/antagonists & inhibitors , Cyclophilins/genetics , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Down-Regulation , Gene Expression Regulation , Gene Silencing , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , HEK293 Cells , Humans , Membrane Potential, Mitochondrial , Methyltransferases/genetics , Methyltransferases/metabolism , Mitochondrial Proteins/genetics , Mitochondrial Proteins/metabolism , Mitochondrial Proton-Translocating ATPases/genetics , NADH Dehydrogenase/genetics , Oxidative Phosphorylation , Promoter Regions, Genetic , Transcription Factors/genetics , Transcription Factors/metabolism , TransfectionABSTRACT
INTRODUCTION: We previously found decreased levels of Coenzyme Q10 (CoQ10) in patients with septic shock. The objective of the current study was to assess whether the provision of exogenous ubiquinol (the reduced form of CoQ10) could increase plasma CoQ10 levels and improve mitochondrial function. METHODS: We performed a randomized, double-blind, pilot trial at a single, tertiary care hospital. Adults (age ≥18 years) with severe sepsis or septic shock between November 2012 and January 2014 were included. Patients received 200 mg enteral ubiquinol or placebo twice a day for up to seven days. Blood draws were obtained at baseline (0 h), 12, 24, 48, and 72 h. The primary outcome of the study was change in plasma CoQ10 parameters (total CoQ10 levels, CoQ10 levels relative to cholesterol levels, and levels of oxidized and reduced CoQ10). Secondary outcomes included assessment of: 1) vascular endothelial biomarkers, 2) inflammatory biomarkers, 3) biomarkers related to mitochondrial injury including cytochrome c levels, and 4) clinical outcomes. CoQ10 levels and biomarkers were compared between groups using repeated measures models. RESULTS: We enrolled 38 patients: 19 in the CoQ10 group and 19 in the placebo group. The mean patient age was 62 ± 16 years and 47% were female. Baseline characteristics and CoQ10 levels were similar for both groups. There was a significant increase in total CoQ10 levels, CoQ10 levels relative to cholesterol levels, and levels of oxidized and reduced CoQ10 in the ubiquinol group compared to the placebo group. We found no difference between the two groups in any of the secondary outcomes. CONCLUSIONS: In this pilot trial we showed that plasma CoQ10 levels could be increased in patients with severe sepsis or septic shock, with the administration of oral ubiquinol. Further research is needed to address whether ubiquinol administration can result in improved clinical outcomes in this patient population. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT01948063. Registered on 18 February 2013.
Subject(s)
Micronutrients/therapeutic use , Sepsis/drug therapy , Shock, Septic/drug therapy , Ubiquinone/analogs & derivatives , Cholesterol/blood , Cytochromes c/blood , Double-Blind Method , Female , Humans , Interleukins/blood , Male , Middle Aged , Pilot Projects , Sepsis/blood , Shock, Septic/blood , Ubiquinone/blood , Ubiquinone/therapeutic use , Vascular Cell Adhesion Molecule-1/blood , Vascular Endothelial Growth Factor A/bloodABSTRACT
Resuscitation from cardiac arrest is partly limited by progressive reduction in left ventricular distensibility, leading to decreased hemodynamic efficacy of cardiopulmonary resuscitation (CPR). Reduction in left ventricular distensibility has been linked to loss of mitochondrial bioenergetic function that can result from oxidative injury. Attenuation of oxidative injury by administration of vitamin C during CPR may help maintain left ventricular distensibility and favor resuscitability and survival. Ventricular fibrillation was electrically induced in 2 series of 16 rats each and left untreated for 10 minutes. Resuscitation was attempted by 8 minutes of CPR and delivery of electrical shocks. Dehydroascorbate (DHA)-an oxidized form of vitamin C that enters the cell via glucose transporters-was used in series 1 and ascorbic acid (AA)-the reduced form of vitamin C that enters the cell via specialized AA transporters-in series 2. In each series, rats were randomized 1:1 to receive a 250 mg/kg right atrial bolus of DHA or AA or vehicle immediately before chest compression. Left ventricular distensibility-measured as the ratio between coronary perfusion pressure and compression depth-was numerically lower (not significant) in rats that received DHA (1.6 ± 0.2 vs. 1.9 ± 0.7 mm Hg/mm) and AA (1.8 ± 0.6 vs. 1.9 ± 0.3 mm Hg/mm). In addition, resuscitability was compromised by DHA (2/8 vs. 7/8; P = 0.041) and by AA (0/8 vs. 5/8; P = 0.026). AA levels in mitochondria were no different than control. Vitamin C failed to preserve left ventricular distensibility during CPR and had detrimental effects on resuscitability, suggesting possible disruption of protective signaling mechanisms during oxidative stress by vitamin C.
Subject(s)
Ascorbic Acid/pharmacology , Cardiopulmonary Resuscitation , Ventricular Fibrillation/physiopathology , Animals , Dehydroascorbic Acid/pharmacology , Hemodynamics , Male , Rats , Rats, Sprague-DawleyABSTRACT
The 2010 guidelines for cardiopulmonary resuscitation recommends that the chest be compressed at least 5 cm, with evidence that depths exceeding 5 cm may further aid resuscitation. The current piston-based mechanical device LUCAS 2™ is programmed to deliver a compression depth of 5 cm. We report 2 cases in which the LUCAS 2™ device failed to generate physiological surrogates of blood flow (ie, end-tidal carbon dioxide tension and aortic diastolic blood pressure) at levels indicative of effective chest compressions. A switch to manual compressions allowing greater compression depth yielded higher end-tidal carbon dioxide tension and arterial blood pressure. These cases depict limitations of the LUCAS 2™ device and the importance of guiding chest compression by physiological parameters. Consideration should be given to modifications to the LUCAS 2™, allowing rescuers to increase depth when required to optimize the hemodynamic efficacy of chest compression.
Subject(s)
Cardiopulmonary Resuscitation/instrumentation , Heart Arrest/therapy , Heart Massage/instrumentation , Aged , Cardiopulmonary Resuscitation/methods , Cardiopulmonary Resuscitation/standards , Fatal Outcome , Heart Massage/methods , Heart Massage/standards , Humans , Male , Practice Guidelines as Topic , Young AdultABSTRACT
Whether initiation of statins could increase survival free of dementia and disability in adults aged ≥75 years is unknown. PREVENTABLE, a double-blind, placebo-controlled randomized pragmatic clinical trial, will compare high-intensity statin therapy (atorvastatin 40 mg) with placebo in 20,000 community-dwelling adults aged ≥75 years without cardiovascular disease, disability, or dementia at baseline. Exclusion criteria include statin use in the prior year or for >5 years and inability to take a statin. Potential participants are identified using computable phenotypes derived from the electronic health record and local referrals from the community. Participants will undergo baseline cognitive testing, with physical testing and a blinded lipid panel if feasible. Cognitive testing and disability screening will be conducted annually. Multiple data sources will be queried for cardiovascular events, dementia, and disability; survival is site-reported and supplemented by a National Death Index search. The primary outcome is survival free of new dementia or persisting disability. Co-secondary outcomes are a composite of cardiovascular death, hospitalization for unstable angina or myocardial infarction, heart failure, stroke, or coronary revascularization; and a composite of mild cognitive impairment or dementia. Ancillary studies will offer mechanistic insights into the effects of statins on key outcomes. Biorepository samples are obtained and stored for future study. These results will inform the benefit of statins for increasing survival free of dementia and disability among older adults. This is a pioneering pragmatic study testing important questions with low participant burden to align with the needs of the growing population of older adults.
Subject(s)
Dementia , Hydroxymethylglutaryl-CoA Reductase Inhibitors , Myocardial Infarction , Stroke , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Myocardial Infarction/drug therapy , Stroke/epidemiology , Dementia/prevention & control , Dementia/drug therapy , LipidsABSTRACT
A variety of CPR techniques and devices may improve hemodynamics or short-term survival when used by well-trained providers in selected patients. All of these techniques and devices have the potential to delay chest compressions and defibrillation. In order to prevent delays and maximize efficiency, initial training, ongoing monitoring, and retraining programs should be offered to providers on a frequent and ongoing basis. To date, no adjunct has consistently been shown to be superior to standard conventional (manual) CPR for out-of-hospital basic life support, and no device other than a defibrillator has consistently improved long-term survival from out-of-hospital cardiac arrest.
Subject(s)
American Heart Association , Cardiology/methods , Cardiopulmonary Resuscitation/instrumentation , Cardiopulmonary Resuscitation/methods , Practice Guidelines as Topic , Cardiology/instrumentation , Cardiology/standards , Cardiopulmonary Resuscitation/standards , Emergency Medical Services/methods , Emergency Medical Services/standards , Heart Arrest/diagnosis , Heart Arrest/therapy , Humans , Practice Guidelines as Topic/standards , United States , Ventilators, Mechanical/standardsSubject(s)
Cardiopulmonary Resuscitation/standards , Emergency Medical Services/standards , Heart Arrest/therapy , Acute Coronary Syndrome/therapy , Adult , Airway Management/methods , Airway Management/standards , Cardiopulmonary Resuscitation/methods , Electric Countershock/standards , Emergency Medical Service Communication Systems/standards , Emergency Medical Services/methods , First Aid/methods , First Aid/standards , Heart Arrest/etiology , Heart Massage/methods , Heart Massage/standards , Humans , Near Drowning/therapy , Out-of-Hospital Cardiac Arrest/epidemiology , Out-of-Hospital Cardiac Arrest/therapy , Respiration, Artificial/instrumentation , Respiration, Artificial/methods , Respiration, Artificial/standards , Stroke/epidemiology , Stroke/therapyABSTRACT
We have previously reported in HEK 293 T cells and in constitutive cyclophilin-D (Cyp-D) knockout (KO) mice that Cyp-D ablation downregulates oxygen consumption (VO2) and triggers an adaptive response that manifest in higher exercise endurance with less VO2. This adaptive response involves a metabolic switch toward preferential utilization of glucose via AMPK-TBC1D1 signaling nexus. We now investigated whether a similar response could be triggered in mice after acute ablation of Cyp-D using tamoxifen-induced ROSA26-Cre-mediated (i.e., conditional KO, CKO) by subjecting them to treadmill exercise involving five running sessions. At their first treadmill running session, CKO mice and controls had comparable VO2 (208.4 ± 17.9 vs. 209.1 ± 16.8 ml/kg min-1), VCO2 (183.6 ± 17.2 vs. 184.8 ± 16.9 ml/kg min-1), and RER (0.88 ± 0.043 vs. 0.88 ± 0.042). With subsequent sessions, CKO mice displayed more prominent reduction in VO2 (genotype & session interaction p = 0.000) with less prominent reduction in VCO2 resulting in significantly increased RER (genotype and session interaction p = 0.013). The increase in RER was consistent with preferential utilization of glucose as respiratory substrate (4.6 ± 0.8 vs. 4.0 ± 0.9 mg/min, p = 0.003). CKO mice also performed a significantly higher treadmill work for given VO2 expressed as a power/VO2 ratio (7.4 ± 0.2 × 10-3 vs. 6.7 ± 0.2 10-3 ratio, p = 0.025). Analysis of CKO skeletal muscle tissue after completion of five treadmill running sessions showed enhanced AMPK activation (0.669 ± 0.06 vs. 0.409 ± 0.11 pAMPK/ß-tubulin ratio, p = 0.005) and TBC1D1 inactivation (0.877 ± 0.16 vs. 0.565 ± 0.09 pTBC1D1/ß-tubulin ratio, p < 0.05) accompanied by increased glucose transporter-4 levels consistent with activation of the AMPK-TBC1D1 signaling nexus enabling increased glucose utilization. Taken together, our study demonstrates that like constitutive Cyp-D ablation, acute Cyp-D ablation also induces a state of increased O2 utilization efficiency, paving the way for exploring the use of pharmacological approach to elicit the same response, which could be beneficial under O2 limiting conditions.