Different Respiratory Rates during Resuscitation in a Pediatric Animal Model of Asphyxial Cardiac Arrest

2024 RECOVER Guidelines: Basic Life Support. Evidence and knowledge gap analysis with treatment recommendations for small animal CPR

OBJECTIVE

To systematically review evidence and devise treatment recommendations for basic life support (BLS) in dogs and cats and to identify critical knowledge gaps.

DESIGN

Standardized, systematic evaluation of literature pertinent to BLS following Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Prioritized questions were each reviewed by 2 Evidence Evaluators, and findings were reconciled by BLS Domain Chairs and Reassessment Campaign on Veterinary Resuscitation (RECOVER) Co-Chairs to arrive at treatment recommendations commensurate to quality of evidence, risk to benefit relationship, and clinical feasibility. This process was implemented using an Evidence Profile Worksheet for each question that included an introduction, consensus on science, treatment recommendations, justification for these recommendations, and important knowledge gaps. A draft of these worksheets was distributed to veterinary professionals for comment for 4 weeks prior to finalization.

SETTING

Transdisciplinary, international collaboration in university, specialty, and emergency practice.

RESULTS

Twenty questions regarding animal position, chest compression point and technique, ventilation strategies, as well as the duration of CPR cycles and chest compression pauses were examined, and 32 treatment recommendations were formulated. Out of these, 25 addressed chest compressions and 7 informed ventilation during CPR. The recommendations were founded predominantly on very low quality of evidence and expert opinion. These new treatment recommendations continue to emphasize the critical importance of high-quality, uninterrupted chest compressions, with a modification suggested for the chest compression technique in wide-chested dogs. When intubation is not possible, bag-mask ventilation using a tight-fitting facemask with oxygen supplementation is recommended rather than mouth-to-nose ventilation.

CONCLUSIONS

These updated RECOVER BLS treatment recommendations emphasize continuous chest compressions, conformation-specific chest compression techniques, and ventilation for all animals. Very low quality of evidence due to absence of clinical data in dogs and cats consistently compromised the certainty of recommendations, emphasizing the need for more veterinary research in this area.

Volumetric capnography and return of spontaneous circulation in an experimental model of pediatric asphyxial cardiac arrest

A secondary analysis of a randomized study was performed to study the relationship between volumetric capnography (VCAP) and arterial CO2 partial pressure (PCO2) during cardiopulmonary resuscitation (CPR) and to analyze the ability of these parameters to predict the return of spontaneous circulation (ROSC) in a pediatric animal model of asphyxial cardiac arrest (CA). Asphyxial CA was induced by sedation, muscle relaxation and extubation. CPR was started 2 min after CA occurred. Airway management was performed with early endotracheal intubation or bag-mask ventilation, according to randomization group. CPR was continued until ROSC or 24 min of resuscitation. End-tidal carbon dioxide (EtCO2), CO2 production (VCO2), and EtCO2/VCO2/kg ratio were continuously recorded. Seventy-nine piglets were included, 26 (32.9%) of whom achieved ROSC. EtCO2 was the best predictor of ROSC (AUC 0.72, p < 0.01 and optimal cutoff point of 21.6 mmHg). No statistical differences were obtained regarding VCO2, VCO2/kg and EtCO2/VCO2/kg ratios. VCO2 and VCO2/kg showed an inverse correlation with PCO2, with a higher correlation coefficient as resuscitation progressed. EtCO2 also had an inverse correlation with PCO2 from minute 18 to 24 of resuscitation. Our findings suggest that EtCO2 is the best VCAP-derived parameter for predicting ROSC. EtCO2 and VCO2 showed an inverse correlation with PCO2. Therefore, these parameters are not adequate to measure ventilation during CPR.

Effects of airway management and tidal volume feedback ventilation during pediatric resuscitation in piglets with asphyxial cardiac arrest

To compare the effect on the recovery of spontaneous circulation (ROSC) of early endotracheal intubation (ETI) versus bag-mask ventilation (BMV), and expiratory real-time tidal volume (VTe) feedback (TVF) ventilation versus without feedback or standard ventilation (SV) in a pediatric animal model of asphyxial cardiac arrest. Piglets were randomized into five groups: 1: ETI and TVF ventilation (10 ml/kg); 2: ETI and TVF (7 ml/kg); 3: ETI and SV; 4: BMV and TVF (10 ml/kg) and 5: BMV and SV. Thirty breaths-per-minute guided by metronome were given. ROSC, pCO2, pO2, EtCO2 and VTe were compared among groups. Seventy-nine piglets (11.3 ± 1.2 kg) were included. Twenty-six (32.9%) achieved ROSC. Survival was non-significantly higher in ETI (40.4%) than BMV groups (21.9%), p = 0.08. No differences in ROSC were found between TVF and SV groups (30.0% versus 34.7%, p = 0.67). ETI groups presented lower pCO2, and higher pO2, EtCO2 and VTe than BMV groups (p < 0.05). VTe was lower in TVF than in SV groups and in BMV than in ETI groups (p < 0.05). Groups 1 and 3 showed higher pO2 and lower pCO2 over time, although with hyperventilation values (pCO2 < 35 mmHg). ETI groups had non significantly higher survival rate than BMV groups. Compared to BMV groups, ETI groups achieved better oxygenation and ventilation parameters. VTe was lower in both TVF and BMV groups. Hyperventilation was observed in intubated animals with SV and with 10 ml/kg VTF.

[Paediatric Life Support]

The European Resuscitation Council (ERC) Paediatric Life Support (PLS) guidelines are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations of the International Liaison Committee on Resuscitation (ILCOR). This section provides guidelines on the management of critically ill or injured infants, children and adolescents before, during and after respiratory/cardiac arrest.

European Resuscitation Council Guidelines 2021: Paediatric Life Support

These European Resuscitation Council Paediatric Life Support (PLS) guidelines, are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the management of critically ill infants and children, before, during and after cardiac arrest.

Comparison of cardiopulmonary resuscitation that applied synchronous 30 compressions–2 ventilations with that applied asynchronous 110/min compression–10/min ventilation: A mannequin study

Background:

CPR model of a resuscitation to be ventilated with a bag valve mask constitutes a discussion when evaluated with the current guidance.

Objective:

This study aims to compare the synchronous (30–2) ventilation–compression method with asynchronous 110/min compression–10/min ventilation in cardiac arrests where an advanced airway management is not applied and where ventilation is provided by a bag valve mask on a mannequin.

Methods:

This simulation trial was performed using two clinical cardiopulmonary resuscitation scenarios: an asynchronous scenario with 10 ventilations per minute asynchronously when compression is applied as 110 compression per minute and a synchronous scenario in which 30 compressions:2 ventilations were performed synchronously. A total of 100 people in 50 groups applied these two scenarios on mannequin. Ventilation and compression data of both scenarios were recorded.

Results:

Evaluating the compression criteria in both the scenarios performed by 50 groups in total, in terms of all criteria except compression fraction, there was no statistically difference between the two scenarios (p > 0.05). Compression fraction values in the asynchronous scenario were found to be statistically significantly higher than the synchronous scenario (96.02 ± 2.35, 81.34 ± 4.42, p < 0.001). Evaluating the ventilation criteria in both the scenarios performed by 50 groups in total; there was a statistically significant difference in all criteria. Mean ventilation rate of the asynchronous scenario was statistically higher than the synchronous scenario (7.22 ± 2.42, 5.08 ± 0.75, p < 0.001). Mean ventilation volume of the synchronous scenario was statistically higher than the asynchronous scenario (353.24 ± 45.46, 527.40 ± 96.60, p < 0.001). Ventilation ratio in sufficient volume of the synchronous scenario was statistically higher than the asynchronous scenario (36.84 ± 14.47, 75.00 ± 21.24, p < 0.001). Ventilation ratio below the minimum volume limit of the asynchronous scenario was statistically higher than the synchronous scenario (62.48 ± 14.72, 17.86 ± 19.50, p < 0.001).

Conclusion:

In our study, we concluded that the cardiopulmonary resuscitation applied by the synchronous method reached better ventilation volumes. Evaluating together with any interruption in compression, comprehensive studies are needed to reveal which patients would benefit from this result.

Effect of ventilation rate on recovery after cardiac arrest in a pediatric animal model

AIMS

To assess the impact of two different respiratory rates in hemodynamic, perfusion and ventilation parameters in a pediatric animal model of cardiac arrest (CA).

METHODS

An experimental randomized controlled trial was carried out in 50 piglets under asphyxial CA. After ROSC, they were randomized into two groups: 20 and 30 respirations per minute (rpm). Hemodynamic, perfusion and ventilation parameters were measured 10 minutes after asphyxia, just before ROSC and at 5, 15, 30 and 60 minutes after ROSC. Independent medians test, Kruskal-Wallis test and χ2 test, were used to compare continuous and categorical variables, respectively. Spearman's Rho was used to assess correlation between continuous variables. A p-value <0.05 was considered significant.

RESULTS

Arterial partial pressure of carbon dioxide (PaCO2) was significantly lower in the 30 rpm group after 15 minutes (41 vs. 54.5 mmHg, p <0.01), 30 minutes (39.5 vs. 51 mmHg, p < 0.01) and 60 minutes (36.5 vs. 48 mmHg, p = 0.02) of ROSC. The percentage of normoventilated subjects (PaCO2 30-50 mmHg) was significantly higher in the 30 rpm group throughout the experiment. pH normalization occurred faster in the 30 rpm group with significant differences at 60 minutes (7.40 vs. 7.34, p = 0.02). Lactic acid levels were high immediately after ROSC in both groups, but were significantly lower in the 20 rpm group at 30 (3.7 vs. 4.7 p = 0.04) and 60 minutes (2.6 vs. 3.6 p = 0.03).

CONCLUSIONS

This animal model of asphyxial CA shows that a respiratory rate of 30 rpm is more effective to reach normoventilation than 20 rpm in piglets after ROSC. This ventilation strategy seems to be safe, as it does not cause hyperventilation and does not affect hemodynamics or cerebral tissue perfusion.

Ventilation Rates and Pediatric In-Hospital Cardiac Arrest Survival Outcomes

OBJECTIVES

The objective of this study was to associate ventilation rates during in-hospital cardiopulmonary resuscitation with 1) arterial blood pressure during cardiopulmonary resuscitation and 2) survival outcomes.

DESIGN

Prospective, multicenter observational study.

SETTING

Pediatric and pediatric cardiac ICUs of the Collaborative Pediatric Critical Care Research Network.

PATIENTS

Intubated children (≥ 37 wk gestation and < 19 yr old) who received at least 1 minute of cardiopulmonary resuscitation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Arterial blood pressure and ventilation rate (breaths/min) were manually extracted from arterial line and capnogram waveforms. Guideline rate was defined as 10 ± 2 breaths/min; high ventilation rate as greater than or equal to 30 breaths/min in children less than 1 year old, and greater than or equal to 25 breaths/min in older children. The primary outcome was survival to hospital discharge. Regression models using Firth penalized likelihood assessed the association between ventilation rates and outcomes. Ventilation rates were available for 52 events (47 patients). More than half of patients (30/47; 64%) were less than 1 year old. Eighteen patients (38%) survived to discharge. Median event-level average ventilation rate was 29.8 breaths/min (interquartile range, 23.8-35.7). No event-level average ventilation rate was within guidelines; 30 events (58%) had high ventilation rates. The only significant association between ventilation rate and arterial blood pressure occurred in children 1 year old or older and was present for systolic blood pressure only (-17.8 mm Hg/10 breaths/min; 95% CI, -27.6 to -8.1; p < 0.01). High ventilation rates were associated with a higher odds of survival to discharge (odds ratio, 4.73; p = 0.029). This association was stable after individually controlling for location (adjusted odds ratio, 5.97; p = 0.022), initial rhythm (adjusted odds ratio, 3.87; p = 0.066), and time of day (adjusted odds ratio, 4.12; p = 0.049).

CONCLUSIONS

In this multicenter cohort, ventilation rates exceeding guidelines were common. Among the range of rates delivered, higher rates were associated with improved survival to hospital discharge.

The use of pressure-controlled mechanical ventilation in a swine model of intraoperative pediatric cardiac arrest

BACKGROUND

Current pediatric resuscitation guidelines suggest that resuscitators using an advanced airway deliver 8-10 breaths per minute while carefully avoiding excessive ventilation. In the intraoperative setting, having a dedicated ventilation rescuer may be difficult because of limited personnel. Continuing pressure-controlled mechanical ventilation during resuscitation for intraoperative cardiac arrest reduces personnel needed and the risk of hyperventilation but might risk hypoventilation during chest compression delivery.

AIMS

To determine whether the use of pressure-controlled mechanical ventilation at prearrest settings provides normoxia and normocarbia during resuscitation from cardiac arrest.

METHODS

We retrospectively analyzed combined data from preclinical randomized controlled trials. Two-week-old swine (3-4 kg) underwent asphyxia-induced cardiac arrest. Animals were resuscitated with periods of basic and advanced life support. During resuscitation, pressure-controlled mechanical ventilation was delivered at the prearrest respiratory rate, peak inspiratory pressure, and positive end-expiratory pressure. Arterial blood gases were measured prearrest, at 11 minutes of asphyxia, and at 8 and 20 minutes of cardiopulmonary resuscitation.

RESULTS

Piglets (n = 154) received pressure-controlled mechanical ventilation before and during cardiopulmonary resuscitation with a peak inspiratory pressure of 14-15 cm H₂ O, positive end-expiratory pressure of 4 cm H₂ O, 20 breaths/minute, and an inspiratory:expiratory ratio of 1:2. During asphyxia, the arterial blood gas showed the expected severe hypercarbia and hypoxia. Continuing pressure-controlled mechanical ventilation using prearrest parameters and increasing the FiO₂ to 1.0 returned the PaCO₂ to prearrest levels and slightly increased the partial pressure of arterial oxygen at 8 and 20 minutes of cardiopulmonary resuscitation.

CONCLUSION

In this piglet model of resuscitation from asphyxial arrest, pressure-controlled mechanical ventilation during cardiopulmonary resuscitation at the prearrest ventilator settings with an FiO₂ of 1.0 provides adequate oxygenation and restores normocarbia. Clinical investigation is warranted to determine the benefits of continuing pressure-controlled mechanical ventilation at prearrest parameters during pediatric cardiopulmonary resuscitation.

Comparison between synchronized and non-synchronized ventilation and between guided and non-guided chest compressions during resuscitation in a pediatric animal model after asphyxial cardiac arrest

Introduction

There are no studies comparing synchronized and non-synchronized ventilation with bag-valve mask ventilation (BVMV) during cardiopulmonary resuscitation (CPR) in pediatric patients. The main aim is to compare between synchronized and non-synchronized BVMV with chest compressions (CC), and between guided and non-guided CC with a real-time feedback-device in a pediatric animal model of asphyxial cardiac arrest (CA). The secondary aim is to analyze the quality of CC during resuscitation.

Methods

60 piglets were randomized for CPR into four groups: Group A: guided-CC and synchronized ventilation; Group B: guided-CC and non-synchronized ventilation; Group C: non-guided CC and synchronized ventilation; Group D: non-guided CC and non-synchronized ventilation. Return of spontaneous circulation (ROSC), hemodynamic and respiratory parameters, and quality of CC were compared between all groups.

Results

60 piglets were included. Twenty-six (46.5%) achieved ROSC: A (46.7%), B (66.7%), C (26.7%) and D (33.3%). Survival rates were higher in group B than in groups A+C+D (66.7% vs 35.6%, p = 0.035). ROSC was higher with guided-CC (A+B 56.7% vs C+D 30%, p = 0.037). Piglets receiving non-synchronized ventilation did not show different rates of ROSC than synchronized ventilation (B+D 50% vs A+C 36.7%, p = 0.297). Non-synchronized groups showed lower arterial pCO₂ after 3 minutes of CPR than synchronized groups: 57 vs 71 mmHg, p = 0.019. No differences were found in arterial pH and pO₂, mean arterial pressure (MAP) or cerebral blood flow between groups. Chest compressions were shallower in surviving than in non-surviving piglets (4.7 vs 5.1 cm, p = 0.047). There was a negative correlation between time without CC and MAP (r = -0.35, p = 0.038).

Conclusions

The group receiving non-synchronized ventilation and guided-CC obtained significantly higher ROSC rates than the other modalities of resuscitation. Guided-CC achieved higher ROSC rates than non-guided CC. Non-synchronized ventilation was associated with better ventilation parameters, with no differences in hemodynamics or cerebral flow.

Comparison between manual and mechanical chest compressions during resuscitation in a pediatric animal model of asphyxial cardiac arrest

Aims

Chest compressions (CC) during cardiopulmonary resuscitation are not sufficiently effective in many circumstances. Mechanical CC could be more effective than manual CC, but there are no studies comparing both techniques in children. The objective of this study was to compare the effectiveness of manual and mechanical chest compressions with Thumper device in a pediatric cardiac arrest animal model.

Material and methods

An experimental model of asphyxial cardiac arrest (CA) in 50 piglets (mean weight 9.6 kg) was used. Animals were randomized to receive either manual CC or mechanical CC using a pediatric piston chest compressions device (Life-Stat®, Michigan Instruments). Mean arterial pressure (MAP), arterial blood gases and end-tidal CO2 (etCO2) values were measured at 3, 9, 18 and 24 minutes after the beginning of resuscitation.

Results

There were no significant differences in MAP, DAP, arterial blood gases and etCO2 between chest compression techniques during CPR. Survival rate was higher in the manual CC (15 of 30 = 50%) than in the mechanical CC group (3 of 20 = 15%) p = 0.016. In the mechanical CC group there was a non significant higher incidence of haemorrhage through the endotracheal tube (45% vs 20%, p = 0.114).

Conclusions

In a pediatric animal model of cardiac arrest, mechanical piston chest compressions produced lower survival rates than manual chest compressions, without any differences in hemodynamic and respiratory parameters.