Mechanical Ventilation May Not Be Essential for Initial Cardiopulmonary Resuscitation

doi:10.1378/chest.108.3.821

Chest

Volume 108, Issue 3, September 1995, Pages 821-827

https://doi.org/10.1378/chest.108.3.821 Get rights and content

Background

In a rodent model of cardiac arrest and resuscitation in which the inspired gas mixture was enriched with oxygen, resuscitability and survival were unaffected by positive pressure ventilation. In the present study, in a larger animal model, tidal volumes generated during precordial compression and with spontaneous gasping were quantitated.

Methods

Domestic pigs with an average weight of 34 kg were anesthetized with pentobarbital. Ventricular fibrillation (VF) was induced electrically. Precordial compression was begun after 4 min of untreated VF. Each of 22 animals received one of two interventions in conjunction with precordial compression: positive pressure ventilation with oxygen or oxygen supplied at the port of a tracheal tube at ambient pressure. After 8 min of precordial compression, defibrillation was attempted.

Results

Only very moderate increases in arterial Pco₂ were documented during cardiopulmonary resuscitation in the absence of mechanical ventilation but arterial oxygen tension was consistently in excess of 100 mm Hg. Cardiac resuscitability and 48-h survival were approximately the same in animals maintained on inspired oxygen whether or not they were mechanically ventilated (7/11 or 8/11). In the absence of mechanical ventilation, precordial compression and spontaneous gasping yielded minute volumes that exceeded 5 L.

Conclusion

Positive pressure mechanical ventilation did not improve resuscitability or postresuscitation outcome in this porcine model of cardiac arrest.

Section snippets

METHODS

All animals received humane care in compliance with the Principles of Laboratory Animal Care formulated by the National Society for Medical Research and the Guide for the Care and Use of Laboratory Animals prepared by the Institute of Laboratory Animal Resources and published by the National Institutes of Health (NIH publications 86-33, revised 1985).

The porcine model of cardiac arrest utilized for these experiments has been described previously.12, 13, 14 Twenty-two immature domestic pigs of

RESULTS

The outcome with respect to cardiac resuscitability and 48-h survival was approximately the same whether or not the animals were mechanically ventilated. Seven of 11 animals receiving positive pressure ventilation and 8 of 11 animals without mechanical ventilatory support were successfully resuscitated (NS). The energy required for successful cardiac defibrillation did not differ significantly between the two groups. All resuscitated animals survived 48 h and there was no neurologic deficit at

DISCUSSION

The present study showed that the combination of precordial compression and spontaneous gasping may generate sufficient minute ventilation for successful cardiac resuscitation during the early stages of CPR. Accordingly, adequate gas exchange may be maintained in the absence of positive pressure ventilation. Even though no important increases in Paco₂ were observed during the course of these studies, earlier observations had indicated that much greater increases to levels of 100 mm Hg did not

REFERENCES (24)

WolfeJA et al.
Physiologic determinant of coronary blood flow during external cardiac massage.
J Thorac Cardiovasc Surg
(1988)
GazmuriRJ et al.
Cardiac effects of carbon dioxide-consuming and carbon dioxide-generating buffers during cardiopulmonary resuscitation.
J Am Coll Cardiol
(1990)
PepePE et al.
Prehospital endotracheal intubation: rationale for training emergency medical personnel.
Ann Emerg Med
(1985)
PepePE et al.
Invasive airway techniques in resuscitation.
Ann Emerg Med
(1993)
DavisPJ et al.
Laryngeal mononeurone activity in the rabbit during asphyxia gasping.
Respir Physiol
(1987)
KouwenhovenWB et al.
Closed chest cardiac massage.
JAMA
(1960)
SafarP et al.
Ventilation and circulation with closed-chest cardiac massage in man.
JAMA
(1961)
Guidelines for cardiopulmonary resuscitation and emergency cardiac care: II. Adult basic life support. JAMA 1992; 268:...
Guidelines for cardiopulmonary resuscitation and emergency cardiac care: III. Adult advanced life support. JAMA 1992;...
MacKenzieGJ et al.
Haemodynamic effects of external cardiac compression.
Lancet
(1964)

BellamyRF et al.

Coronary blood flow during cardiopulmonary resuscitation in swine.

Circulation

(1984)

ChandraNC et al.

Ventilation during CPR [Abstract].

Circulation

(1991)

Cited by (153)

Do manual chest compressions provide substantial ventilation during prehospital cardiopulmonary resuscitation?
2021, American Journal of Emergency Medicine
Chest compressions have been suggested to provide passive ventilation during cardiopulmonary resuscitation. Measurements of this passive ventilatory mechanism have only been performed upon arrival of out-of-hospital cardiac arrest patients in the emergency department. Lung and thoracic characteristics rapidly change following cardiac arrest, possibly limiting the effectiveness of this mechanism after prolonged resuscitation efforts. Goal of this study was to quantify passive inspiratory tidal volumes generated by manual chest compression during prehospital cardiopulmonary resuscitation.
A flowsensor was used during adult out-of-hospital cardiac arrest cases attended by a prehospital medical team. Adult, endotracheally intubated, non-traumatic cardiac arrest patients were eligible for inclusion. Immediately following intubation, the sensor was connected to the endotracheal tube. The passive inspiratory tidal volumes generated by the first thirty manual chest compressions performed following intubation (without simultaneous manual ventilation) were calculated.
10 patients (5 female) were included, median age was 64 years (IQR 56, 77 years). The median compression frequency was 111 compression per minute (IQR 107, 116 compressions per minute). The median compression depth was 5.6 cm (IQR 5.4 cm, 6.1 cm). The median inspiratory tidal volume generated by manual chest compressions was 20 mL (IQR 13, 28 mL).
Using a flowsensor, passive inspiratory tidal volumes generated by manual chest compressions during prehospital cardiopulmonary resuscitation, were quantified. Chest compressions alone appear unable to provide adequate alveolar ventilation during prehospital treatment of cardiac arrest.
Quantification of ventilation volumes produced by compressions during emergency department cardiopulmonary resuscitation
2018, American Journal of Emergency Medicine
Clinical investigations have shown improved outcomes with primary compression cardiopulmonary resuscitation strategies. It is unclear whether this is a result of passive ventilation via chest compressions, a low requirement for any ventilation during the early aspect of resuscitation or avoidance of inadvertent over-ventilation.
To quantify whether chest compressions with guideline-compliant depth (>2 in) produce measurable and substantial ventilation volumes during emergency department resuscitation of out-of-hospital cardiac arrest.
This was a prospective, convenience sampling of adult non-traumatic out-of-hospital cardiac arrest patients receiving on-going cardiopulmonary resuscitation in an academic emergency department from June 1, 2011 to July 30, 2013. Cardiopulmonary resuscitation quality files were analyzed using R-Series defibrillator/monitors (ZOLL Medical) and ventilation data were measured using a Non-Invasive Cardiac Output monitor (Philips/Respironics, Wallingford, CT).
cardiopulmonary resuscitation quality data were analyzed from 21 patients (17 males, median age 59). The median compression depth was 2.2 in (IQR = 1.9, 2.5) and the median chest compression fraction was 88.4% (IQR = 82.2, 94.1). We were able to discern 580 ventilations that occurred during compressions. The median passive tidal volume recorded during compressions was 7.5 ml (IQR 3.5, 12.6). While the highest volume recorded was 45.8 ml, 81% of the measured tidal volumes were <20 ml.
Ventilation volume measurements during emergency department cardiopulmonary resuscitation after out-of-hospital cardiac arrest suggest that chest compressions alone, even those meeting current guideline recommendations for depth, do not provide physiologically significant tidal volumes.
Evaluation of the Boussignac Cardiac arrest device (B-card) during cardiopulmonary resuscitation in an animal model
2017, Resuscitation
The purpose of this study was to examine continuous oxygen insufflation (COI) in a swine model of cardiac arrest. The primary hypothesis was COI during standard CPR (S-CPR) should result in higher intrathoracic pressure (ITP) during chest compression and lower ITP during decompression versus S-CPR alone. These changes with COI were hypothesized to improve hemodynamics. The second hypothesis was that changes in ITP with S-CPR + COI would result in superior hemodynamics compared with active compression decompression (ACD) + impedance threshold device (ITD) CPR, as this method primarily lowers ITP during chest decompression.
After 6 min of untreated ventricular fibrillation, S-CPR was initiated in 8 female swine for 4 min, then 3 min of S-CPR + COI, then 3 min of ACD + ITD CPR, then 3 min of S-CPR + COI. ITP and hemodynamics were continuously monitored.
During S-CPR + COI, ITP was always positive during the CPR compression and decompression phases. ITP compression values with S-CPR + COI versus S-CPR alone were 5.5 ± 3 versus 0.2 ± 2 (p < 0.001) and decompression values were 2.8 ± 2 versus −1.3 ± 2 (p < 0.001), respectively. With S-CPR + COI versus ACD + ITD the ITP compression values were 5.5 ± 3 versus 1.5 ± 2 (p < 0.01) and decompression values were 2.8 ± 2 versus −4.7 ± 3 (p < 0.001), respectively.
COI during S-CPR created a continuous positive pressure in the airway during both the compression and decompression phase of CPR. At no point in time did COI generate a negative intrathoracic pressures during CPR in this swine model of cardiac arrest.
Detection and quantification of gasping during resuscitation for out-of-hospital cardiac arrest
2017, Resuscitation
To detect and quantify gasping during cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrest (OHCA) patients and to investigate whether gasping is associated with increased return of spontaneous circulation (ROSC).
A prospective observational study in patients resuscitated and mechanically or manually ventilated for OHCA by emergency physicians of Ghent University Hospital. After intubation, pressure catheters were inserted in the endotracheal tube (ETT) and pressures were measured at the proximal and distal ends of the ETT. Gasping was analysed with custom-developed software and volumes were calculated based on pressure differences between the catheters. Data are expressed as median (interquartile range).
Data were collected in 292 resuscitated patients of whom 36.2% achieved ROSC. Seventy-six of 292 (26.0%) patients showed gasping on the pressure curves during resuscitation. The median gasping volume was 274 ml (196–434). The median gasping rate was 3.7 gasps/min (1.5–7.3). Gasping occurred significantly more in patients displaying ventricular fibrillation as the initial rhythm compared to patients with pulseless electrical activity, pulseless ventricular tachycardia or asystole. The median gasping rate was significantly higher in the ROSC group compared to the non-ROSC group (11.8 gasps/min (95% CI [4.2, 13.9]) and 2.8 gasps/min (95% CI [1.7, 3.9]) respectively (P < 0.001)). A gasping rate of >7.3 gasps/min appeared to be the optimal criterion value to herald ROSC. Deeper negative pressures were associated with an increased incidence of ROSC (P = 0.011). There was no significant difference in ROSC between patients with gasping and those without.
The occurrence of gasping during CPR was high. Significant gasping volumes were measured. The presence or absence of gasping was not associated with ROSC, but higher gasping rate and deeper negative pressures were.
Association of presence and timing of invasive airway placement with outcomes after pediatric in-hospital cardiac arrest
2015, Resuscitation
Little data exist regarding the association of presence of an invasive airway before cardiac arrest or early placement of an invasive airway after cardiac arrest with outcomes in children who experience in-hospital cardiac arrest.
We conducted a retrospective review of patients aged 1 day to 18 years who received cardiopulmonary resuscitation (CPR) for ≥1 min in any of the three intensive care units (ICUs) at a tertiary care, academic children's hospital between 2002 and 2010. Specific outcomes evaluated included survival to hospital discharge, return of spontaneous circulation (ROSC), 24-h survival, and good neurological status at hospital discharge. We fitted multivariable logistic regression models to evaluate the association between the presence of an invasive airway prior to cardiac arrest and timing of placement of an invasive airway with these outcomes.
Three hundred and ninety-one patients were included. Of these, 197 (51%) patients were already tracheally intubated before the occurrence of cardiac arrest. Median time to intubation was 6 min [interquartile range (IQR): 2, 12] among the 194 patients tracheally intubated following cardiac arrest. We found lower survival to hospital discharge among patients intubated prior to cardiac arrest (intubated vs. non-intubated group, 43% vs. 61%, p < 0.001). After adjusting for patient and event characteristics, presence of an invasive airway prior to cardiac arrest was not associated with a significant improvement in survival to hospital discharge [odds ratio (OR): 0.70, 95% confidence interval (CI): 0.42–1.16, p = 0.17], or good neurological outcomes (OR: 0.60, 95% CI: 0.34–1.05, p = 0.07). Similarly, early placement of an invasive airway after cardiac arrest was also not associated with an improvement in survival to hospital discharge (OR: 1.05, 95% CI: 0.78–1.42, p = 0.73), or good neurological outcomes (OR: 1.08, 95% CI: 0.77–1.53, p = 0.65).
Our study demonstrates that presence of an invasive airway prior to cardiac arrest or early placement of an invasive airway after cardiac arrest is not associated with an improvement in survival to hospital discharge or good neurological outcomes. Further study of the relationship between invasive airway management and survival following cardiac arrest is warranted.
A randomized trial of continuous versus interrupted chest compressions in out-of-hospital cardiac arrest: Rationale for and design of the Resuscitation Outcomes Consortium Continuous Chest Compressions Trial
2015, American Heart Journal
Citation Excerpt :
Compression-induced ventilation is common with passive inhalation of gas, after elastic recoil of the chest wall during the relaxation phase.15-19 This ventilation may be substantial16,18-21 but can decrease after 4 to 10 minutes of CPR due to progressive atelectasis and chest wall deformity.16,22 Spontaneous gasping (ie, agonal breathing) also contributes to total ventilation.18,19,22,23
The Resuscitation Outcomes Consortium is conducting a randomized trial comparing survival with hospital discharge after continuous chest compressions without interruption for ventilation versus currently recommended American Heart Association cardiopulmonary resuscitation with interrupted chest compressions in adult patients with out-of-hospital cardiac arrest without obvious trauma or respiratory cause. Emergency medical services perform study cardiopulmonary resuscitation for 3 intervals of manual chest compressions (each ~2 minutes) or until restoration of spontaneous circulation. Patients randomized to the continuous chest compression intervention receive 200 chest compressions with positive pressure ventilations at a rate of 10/min without interruption in compressions. Those randomized to the interrupted chest compression study arm receive chest compressions interrupted for positive pressure ventilations at a compression:ventilation ratio of 30:2. In either group, each interval of compressions is followed by rhythm analysis and defibrillation as required. Insertion of an advanced airway is deferred for the first ≥6 minutes to reduce interruptions in either study arm. The study uses a cluster randomized design with every-6-month crossovers. The primary outcome is survival to hospital discharge. Secondary outcomes are neurologically intact survival and adverse events. A maximum of 23,600 patients (11,800 per group) enrolled during the post-run-in phase of the study will provide ≥90% power to detect a relative change of 16% in the rate of survival to discharge, 8.1% to 9.4% with overall significance level of 0.05. If this trial demonstrates improved survival with either strategy, >3,000 premature deaths from cardiac arrest would be averted annually.

View all citing articles on Scopus

: Supported in part by National Heart Lung and Blood Institute grants 1-R01-HL39148 and 1-R01-HL42590; Institute of Critical Care Medicine, Palm Springs, Calif; Laerdal Foundation for Acute Medicine, Stavanger, Norway; and grant-in-aid from American Heart Association and partly by AHA Illinois Affiliate Inc.

View full text

Chest

Laboratory and Animal InvestigationsMechanical Ventilation May Not Be Essential for Initial Cardiopulmonary Resuscitation

Background

Methods

Results

Conclusion

Section snippets

METHODS

RESULTS

DISCUSSION

J Thorac Cardiovasc Surg

J Am Coll Cardiol

Ann Emerg Med

Ann Emerg Med

Respir Physiol

Closed chest cardiac massage.

JAMA

Ventilation and circulation with closed-chest cardiac massage in man.

JAMA

Haemodynamic effects of external cardiac compression.

Lancet

Coronary blood flow during cardiopulmonary resuscitation in swine.

Circulation

Ventilation during CPR [Abstract].

Circulation

Laboratory and Animal Investigations
Mechanical Ventilation May Not Be Essential for Initial Cardiopulmonary Resuscitation