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J J Menegazzi

Publications and source records attributed to J J Menegazzi.

At least 19 recordsLinked to original sources
PubMed2001

Use of a cardiocerebral-protective drug cocktail prior to countershock in a porcine model of prolonged ventricular fibrillation.

OBJECTIVES: This was the third study in a series exploring whether the use of combination pharmacotherapy with delayed countershock would produce higher rates of return of spontaneous circulation (ROSC) and one-hour survival when compared with standard advanced cardiac life support (ACLS) therapy in prolonged ventricular fibrillation (VF). METHODS: Twenty-four female, mixed-breed, domestic swine (ranging in mass from 22 to 25 kg) were used in this prospective, blinded, randomized, experimental trial. Animals were sedated (ketamine/xylazine), anesthetized (alpha-chloralose), paralyzed (pancuronium), mechanically ventilated with room air, and monitored with electrocardiography, arterial pressure, and Swan-Ganz catheters. VF was induced with a 3 s, 60 Hz, 100 mA transthoracic shock, and remained untreated for 8 min. One minute of basic life support followed (standardized by use of a mechanical device). At 9 min, animals were treated with one of three regimes: Group 1, cardiocerebral-protective cocktail (antioxidant U-74389G (3.0 mg/kg), epinephrine (0.2 mg/kg), lidocaine (1.0 mg/kg), bretylium (5.0 mg/kg), magnesium (2.0 g), and propranolol (1.0 mg)); Group 2, magnesium (2.0 g); and Group 3, standard ACLS. Groups 1 and 2 received drugs at minute nine (first countershock at minute 11), while Group 3 received first countershock at minute nine. Data were analyzed with two-tailed Fisher's exact tests. RESULTS: ROSC was achieved in Group 1, 7/7 (100%); Group 2, 3/9 (33%, P versus Group 1=0.01); and Group 3, 3/8 (38%; P versus Group 1=0.02). One-hour survival was attained in Group 1, 7/7 (100%); Group 2, 3/9 (33%; P versus Group 1=0.01), and Group 3, 1/8 (13%; P versus Group 1=0.001). CONCLUSIONS: Combination pharmacotherapy with a cardiocerebral-protective drug cocktail prior to countershock produced superior rates of ROSC and one-hour survival when compared with singular drug therapy (Group 2) and standard ACLS (Group 3) in this porcine model of prolonged VF.

Advanced Cardiac Life Support↗
PubMed2001

Effects of biphasic vs monophasic defibrillation on the scaling exponent in a swine model of prolonged ventricular fibrillation.

OBJECTIVE: Mathematical analyses of ventricular fibrillation (VF) have resulted in the derivation of a measure termed the scaling exponent (ScE) that characterizes the duration of VF and probability of defibrillation success. The purpose of this study was to compare the effects of biphasic defibrillation waveform (BDW) and monophasic defibrillation waveform (MDW) rescue shocks on ScE in a swine model of prolonged VF. METHODS: Utstein guidelines for the laboratory study of cardiopulmonary resuscitation were followed. Twenty mixed-breed domestic swine (mass range 20.5-26.8 kg) were instrumented and randomized to receive either MDW or BDW rescue shocks. Ventricular fibrillation was induced and untreated for a nonintervention interval of 8 minutes. Rescue shocks were delivered at 8, 10, and 12 minutes of elapsed VF time. The energy sequence for the three MDW shocks was 70, 100, and 150 J (approximately 3, 4, and 6 J/kg). All BDW shocks were delivered at 50 J (approximately 2.5 J/kg). Only VF was shocked. Chest compressions and drugs were not provided. Rhythm analysis and ScE calculation were performed offline. Continuous and discontinuous linear regression models were fit to plots of ScE vs time. Defibrillation success and progression of ScE slope were analyzed using Fisher's exact test, paired t-tests, and repeated-measures analysis of variance (ANOVA). RESULTS: Baseline characteristics were similar for both groups. Successful termination of VF occurred on the first rescue shock in 1 of 10 (10%) in the MDW group and 3 of 10 (30%) in the BDW group; this difference was not statistically significant (p = 0.58). No other defibrillation successes were observed. No animals achieved return of spontaneous circulation. The ScE values during the protocol progressed from 1.330 (95% CI = 1.287 to 1.373) to 1.724 (95% CI = 1.603 to 1.845) for MDW and 1.338 (95% CI = 1.261 to 1.415) to 1.639 (95% CI = 1.530 to 1.745) for BDW. Both groups showed a trend toward increasing ScE values with successive rescue shocks. Repeated-measures ANOVA using both continuous and discontinuous models demonstrated no difference in overall ScE slope progression between study groups. CONCLUSIONS: Mode of defibrillation waveform (BDW vs MDW) does not appear to impact ScE trends. Additional studies must be performed to better evaluate the clinical implications of this finding.

Animals↗
PubMed2001

Bench to bedside: resuscitation from prolonged ventricular fibrillation.

Ventricular fibrillation (VF) remains the most common cardiac arrest heart rhythm. Defibrillation is the primary treatment and is very effective if delivered early within a few minutes of onset of VF. However, successful treatment of VF becomes increasingly more difficult when the duration of VF exceeds 4 minutes. Classically, successful cardiac arrest resuscitation has been thought of as simply achieving restoration of spontaneous circulation (ROSC). However, this traditional approach fails to consider the high early post-cardiac arrest mortality and morbidity and ignores the reperfusion injuries, which are manifest in the heart and brain. More recently, resuscitation from cardiac arrest has been divided into two phases; phase I, achieving ROSC, and phase II, treatment of reperfusion injury. The focus in both phases of resuscitation remains the heart and brain, as prolonged VF remains primarily a two-organ disease. These two organs are most sensitive to oxygen and substrate deprivation and account for the vast majority of early post-resuscitation mortality and morbidity. This review focuses first on the initial resuscitation (achieving ROSC) and then on the reperfusion issues affecting the heart and brain.

Animals↗
PubMed2000

Ventricular fibrillation exhibits dynamical properties and self-similarity.

Electrocardiographic recordings of ventricular fibrillation (VF) appear chaotic. Previous attempts to characterize the chaotic nature of VF have relied on peak-to-peak intervals [Witkowski et al., Phys. Rev. Lett. 1995;75(6):1230-3; Garfinkel et al., J. Clin. Investig. 1997;99(2):305-314; Hastings et al., Proc. Natl. Acad. Sci. USA 1996;93:10495-9], the frequency spectrum [Goldberger et al., 1986;19:282-289] or other derived measures [Kaplan and Cohen, Circ. Res. 1990;67:886-92], with results that demonstrate some characteristics of chaos. We have sought to determine whether VF is chaotic rather than random and whether the waveform can be described quantitatively using the tools of fractal geometry. We have constructed an attractor, measured the correlation dimensions, estimated the embedding dimension and measured Lyapunov exponents. When the digitized waveform is analyzed directly, VF exhibits nonrandom, chaotic behavior over a decade of sampling frequency. Within the scaling range we have estimated the Hurst exponent, and the self-similarity dimension of the VF waveform, supporting the presence of chaotic dynamics. Furthermore, these characteristics are measurable in a porcine model of VF under different recording conditions, and in VF recordings taken from human subjects immediately prior to defibrillation. Analyses of the Hurst exponents and self-similarity dimensions are correlated with the duration of VF, which may have clinical applications.

Animals↗
PubMed2000

Scaling structure of electrocardiographic waveform during prolonged ventricular fibrillation in swine.

Ventricular fibrillation (VF) is the most common arrhythmia causing sudden cardiac death. However, the likelihood of successful defibrillation declines with increasing duration of VF. Because the morphology of the electrocardiogram (ECG) waveform during VF also changes with time, this study examined a new measure that describes the VF waveform and distinguishes between early and late VF. Surface ECG recordings were digitized at 200 samples/s from nine swine with induced VF. A new measure called the scaling exponent was calculated by examining the power-law relationship between the summation of amplitudes of a 1,024-point (5.12 second) waveform segment and the time scale of measurement. The scaling exponent is a local estimate of the fractal dimension of the ECG waveform. A consistent power-law relationship was observed for measurement time scales of 0.005-0.040 seconds. Calculation of the scaling exponent produced similar results between subjects, and distinguished early VF (< 4-minute duration) from late VF (> or = 4-minute duration). The scaling exponent was dependent on the order of the data, supporting the hypothesis that the surface ECG during VF is a deterministic rather than a random signal. The waveform of VF results from the interaction of multiple fronts of depolarization within the heart, and may be described using the tools of nonlinear dynamics. As a quantitative descriptor of waveform structure, the scaling exponent characterizes the time dependent organization of VF.

Animals↗
PubMed2000

Two-thumb vs. two-finger chest compression in an infant model of prolonged cardiopulmonary resuscitation.

OBJECTIVE: Previous experiments in the authors' swine lab have shown that cardiopulmonary resuscitation (CPR) using two-thumb chest compression with a thoracic squeeze (TT) produces higher blood and perfusion pressures when compared with the American Heart Association (AHA)-recommended two-finger (TF) technique. Previous studies were of short duration (1-2 minutes). The hypothesis was that TT would be superior to TF during prolonged CPR in an infant model. METHODS: This was a prospective, randomized crossover experiment in a laboratory setting. Twenty-one AHA-certified rescuers performed basic CPR for two 10-minute periods, one with TT and the other with TF. Trials were separated by 2-14 days, and the order was randomly assigned. The experimental circuit consisted of a modified manikin with a fixed-volume arterial system attached to a neonatal monitor via an arterial pressure transducer. The arterial circuit was composed of a 50-mL bag of normal saline solution (air removed) attached to the manikin chest plate and connected to the transducer with a 20-gauge intravenous catheter and tubing. Rescuers were blinded to the arterial pressure tracing. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were recorded in mm Hg, and pulse pressures (PPs) were calculated. Data were analyzed with two-way repeated-measures analysis of variance. Sphericity assumed modeling, with Greenhouse-Geisser and Huynh-Feldt adjustments, was applied. RESULTS: Marginal means for TT SBP (68.9), DBP (17.6), MAP (35.3), and PP (51.4) were higher than for TF SBP (44.8), DBP (12.5), MAP (23.3), and PP (32.2). All four pressures were significantly different between the two techniques (p< or =0.001). CONCLUSION: In this infant CPR model, TT chest compression produced higher MAP, SBP, DBP, and PP when compared with TF chest compression during a clinically relevant duration of prolonged CPR.

Adult↗
PubMed1999

Statistical methodology: IX. survival analysis.

Survival analysis is a group of statistical methods used to analyze data representing the time to an event of interest, e.g., the duration of survival after an out-of-hospital cardiac arrest or the length of time a patient stays in the ED. Survival analysis properly accounts for patients who are lost to follow-up and for patients who have not yet experienced the event of interest at the end of the study's observation period (censored data). This article acquaints the reader with the terminology, methodology, and limitations of survival analysis. Specific methods discussed include life tables, the Kaplan-Meier product limit estimate, the log-rank test, and the multivariate Cox proportional hazards model.

Cardiopulmonary Resuscitation↗
PubMed1999

Evaluation of biphasic transthoracic defibrillation in an animal model of prolonged ventricular fibrillation.

OBJECTIVES: To determine whether a biphasic defibrillation waveform (BDW) would produce a superior rate of converting prolonged ventricular fibrillation (VF) into a perfusing rhythm and delay the occurrence of asystole and/or pulseless electrical activity (PEA) during the resuscitation attempt, when compared with a monophasic defibrillation waveform (MDW). METHODS: The authors performed a prospective, randomized, blinded experiment using an established swine model of prolonged VF. Thirty-four mixed-breed domestic swine (mean mass 22.9 kg) were sedated (ketamine/xylazine), anesthetized (isoflurane), and intubated. Aortic and femoral venous catheters were placed. ECG was monitored continuously. The animals were shocked into VF (3-s, 100-mA, 60-Hz shock), and were untreated for 8 minutes. Advanced Cardiac Life Support (ACLS) began with 1 minute of standardized (Thumper) chest compressions and ventilation. The animals were randomized to treatment with either BDW or MDW. Standard ACLS protocols were followed. The energy sequence was 2.5 J/kg first, 3.5 J/kg second, and 4.5 J/kg for all subsequent shocks. Outcome variables were time to event of asystole/PEA, return of spontaneous circulation (ROSC), and one-hour survival. Data were analyzed with two-tailed Fisher's exact test and Kaplan-Meier survival plots (alpha = 0.05). RESULTS: ROSC occurred more frequently in the BDW group (7/17) compared with the MDW group (1/17); p = 0.04. Survival analysis showed that the BDW significantly delayed the occurrence of asystole/PEA during the resuscitation attempt when compared with the MDW; log-ranked p = 0.02. One-hour survival rates (5/17 BDW and 1/17 MDW, p = 0.17) did not differ. CONCLUSIONS: BDW resulted in a superior rate of ROSC and delay in the occurrence of asystole/ PEA during the resuscitation attempt when compared with MDW.

Animals↗
PubMed1998

Experimental tricyclic antidepressant toxicity: a randomized, controlled comparison of hypertonic saline solution, sodium bicarbonate, and hyperventilation.

STUDY OBJECTIVE: We sought to compare the effects of hypertonic sodium chloride solution (HTS), sodium bicarbonate solution, and hyperventilation (HV) on severe tricyclic antidepressant (TCA) toxicity in a swine model. METHODS: Twenty-four mixed-breed, domestic swine of either sex were given an intravenous infusion of nortriptyline (NT) until development of both a QRS duration longer than 120 ms and a systolic blood pressure (SBP) less than or equal to 50 mm Hg. Animals were randomly assigned to 1 of 4 groups. On reaching toxicity, the control group received 10 mL/kg of 5% dextrose in water (D5W); the HTS group received 10 mL/kg of 7.5% NaCl solution (15 mEq Na+/kg); the NaHCO3 group received 3 mEq/kg of 8.4% sodium bicarbonate solution followed by enough D5W solution to equal 10 mL/kg of total volume; and the HV group was mechanically hyperventilated to maintain arterial pH between 7.50 and 7.60 and given 10 mL/kg of D5W. RESULTS: The mean SBP 10 minutes after treatment was 54+/-18 mm Hg in the control group, 134+/-21 mm Hg in the HTS group, 85+/-19 mm Hg in the NaHCO3 group, and 60+/-12 mm Hg in the HV group (P<.05). Mean QRS duration 10 minutes after treatment was 144+/-38 ms in the control group, 80+/-14 ms in the HTS group, 105+/-38 ms in the NaHCO3 group, and 125+/-46 ms in the HV group (P<.05). CONCLUSION: In this model of TCA, toxicity HTS was more effective than sodium bicarbonate. Hyperventilation had little effect. Sodium loading may be the most important factor in reversing TCA toxicity.

Animals↗
PubMed1998

Noninvasive cerebral cooling in a swine model of cardiac arrest.

OBJECTIVE: Mild cerebral hypothermia improves neurologic outcome in animals resuscitated from cardiac arrest. This study examined whether one practical external cooling method, i.e., local application of ice to the heads and necks of swine, during resuscitation induces cerebral cooling. METHODS: Local external cerebral cooling was examined in a prospective laboratory investigation using 24 female swine in a model of cardiac arrest. The swine were randomized into hypothermia and normothermia groups. Intracerebral temperature was measured in the parietal cortex. Eight minutes after induction of ventricular fibrillation, chest compressions and mechanical ventilation were initiated. The hypothermia group was treated with 1,500 mL of ice in plastic bags applied to the head and neck, while the normothermia group received no extra interventions. Data were analyzed using repeated-measures ANOVA. RESULTS: In the normothermia group, there was no significant change in nasopharyngeal (-0.8 +/- 0.6 degree C), intracerebral (-0.6 +/- 0.8 degree C), or esophageal (-0.2 +/- 0.6 degree C) temperatures during 20 minutes of resuscitation. However, in the hypothermia group, application of ice during resuscitation significantly reduced nasopharyngeal (-2.9 +/- 1.4 degrees C), intracerebral (-2.1 +/- 0.6 degrees C), and esophageal (-1.4 +/- 0.8 degrees C) temperatures. CONCLUSIONS: External application of ice packs during resuscitation effectively reduced intracerebral temperatures in swine by an amount that improved neurologic outcomes in previous large animal studies. These data suggest that clinically significant cerebral cooling could be accomplished with a noninvasive, inexpensive, and universally available intervention. Further studies are required to assess the clinical feasibility and therapeutic efficacy of this intervention.

Analysis of Variance↗
PubMed1997

Aminophylline as an adjunct to standard advanced cardiac life support in prolonged cardiac arrest.

STUDY HYPOTHESIS: We hypothesized that the addition of aminophylline to Advanced Cardiac Life Support (ACLS) interventions would improve the initial resuscitation success rate in an animal model of prolonged cardiac arrest. METHODS: We used a double-blind, placebo-controlled, randomized-block design with a follow-up open-label uncontrolled phase. We studied 24 female domestic mixed-breed swine (body mass, 20 to 25 kg). After electrical induction of ventricular fibrillation, animals were subjected to 8 minutes of no-flow cardiac arrest followed by 1 minute of mechanical ventilation and closed-chest compressions. Nine minutes after arrest, equal numbers of swine received 6 mg/kg intravenous aminophylline (treatment group) and a saline solution placebo (control group), another minute of basic CPR, and standardized ACLS interventions beginning at 10 minutes. Initial resuscitation efforts were continued for at least 20 minutes. In all animals, if initial efforts failed, 6.0 mg/kg intravenous aminophylline, open label, and 10 minutes of additional resuscitation were administered. The primary outcome variables were return of spontaneous circulation (ROSC) and 1-hour survival. We compared groups with the two-tailed Fisher exact test. RESULTS: ROSC occurred in 4 of 12 animals in the treatment group (33%) and 3 of 12 in the control group (25%) (P=.50). Late administration of aminophylline did not result in ROSC in any animal. Survival to 1 hour was greater in the treatment group (4 of 12, 33%) than in the control group (1 of 12, 8%) (P=.16). CONCLUSION: Addition of aminophylline to standard ACLS interventions did not increase the incidence of ROSC or the 1-hour survival rate in a swine model of prolonged cardiac arrest.

Aminophylline↗
PubMed1996

Analgesic practice for acute orthopedic trauma pain in Costa Rican emergency departments.

STUDY OBJECTIVE: Studies in US emergency departments have demonstrated that pain is undertreated in adults and children. Previous studies have also demonstrated cultural differences in the expression and perception of pain. The objective of this investigation was to describe the analgesic practices and patient pain responses in two Costa Rican EDs in light of possible differences due to cultural variation. METHODS: We carried out a prospective, noninterventional observational assessment protocol of a convenience sample of patients being treated for orthopedic trauma in two university-affiliated urban teaching hospital EDs. Children between the ages of 5 and 12 years and all adults, ages 16 to 63, who presented with painful orthopedic trauma were included. Patients quantified their pain on arriving at and before leaving the ED. Children used a Face Interval Scale ranging from 1 (no pain) to 9 (maximum pain), and adults used a numeric rating scale ranging from 0 to 10. RESULTS: One fourth of pediatric and more than half of all adult patients had no reduction in their pain scores on leaving the ED. Eleven percent of adults and fewer than 4% of children received pain treatment while in the ED. Fewer than half of all patients were sent home with analgesics. We observed no use of opioids in the ED for analgesia. CONCLUSION: Our data illustrate that both adults and children with severe pain resulting from orthopedic injury in the Costa Rican EDs we studied often receive inadequate or no analgesic treatment. This finding suggests that the phenomenon of oligoanalgesia is more widespread and resistant to cultural differences. We also noted a reluctance to use opioids in this setting.

Acute Disease↗
PubMed1996

Demand valve ventilation in a swine pneumothorax model.

Bag-valve-mask (BVM) and oxygen-powered demand valve (OPDV) are two available adjuncts for artificial ventilation. Use of OPVDs has been limited by concern for causing or worsening pneumothorax. This study examined the effect of OPDV and BVM ventilation in swine with pneumothorax. This was a randomized, crossover design. Five female swine (16 to 23 kg) were sedated (ketamine/xylazine), anesthetized (alpha chloralose), and intubated. Right chest injury was induced, through an incision, using a 14-gauge needle to produce disruption of underlying lung parenchyma. An 18F Foley catheter was inserted and sealed in the right pleural space at the cut-down site. For each trial, a pneumothorax was induced by instilling 300 mL of air. Each subject underwent 10-minute ventilation trials with OPDV and with BVM by the same investigator, blinded to instrumentation. Post-trial pneumothorax volume, heart rate, blood pressure, end-tidal CO2 (ETCO2), and arterial blood gases were measured. There was no significant difference in pneumothorax volume after OPDV ventilation (310.8 mL) versus BVM ventilation (315.4 mL) (P = .821). There were no significant differences between heart rates, blood pressures, or arterial blood gases, although ETCO2 showed statistically significant decreases from baseline in both OPDV (33.0 to 28.6) and BVM (33.8 to 30.2) trials. However, multiple comparisons showed no significant differences between OPDV and BVM at any time points. In this model, OPDV and BVM ventilation did not differ in their effects on pneumothorax volume or hemodynamic variables. No animal showed signs of tension pneumothorax.

Animals↗
PubMed1995

Lower esophageal sphincter pressure during prolonged cardiac arrest and resuscitation.

STUDY OBJECTIVE: Unprotected airway ventilation models have been based on a lower esophageal sphincter (LES) pressure found in human beings under general anesthesia. Whether this assumption is applicable during cardiac arrest in human beings is unknown. We attempted to determine the effects of prolonged ventricular fibrillation (VF) on the tension of the LES in a swine model of cardiac arrest. DESIGN: Prospective experimental trial using 18 female mixed-breed domestic swine (mean weight, 21.9 +/- 2.0 kg). RESULTS: Animals were anesthetized, intubated, and fitted with instruments for the monitoring of LES pressure. LES tone was measured with a LECTRON 302 esophageal monitor (American Antec, Incorporated). VF was induced with a 3-second, 100 mA transthoracic shock and left untreated for 8 minutes; then resuscitation was attempted. LES tension was measured during the first 7 minutes of the arrest. If return of spontaneous circulation (ROSC) occurred, LES pressure was measured for 7 more minutes. The mean baseline LES pressure was 20.6 +/- 2.8 cm H2O. During minutes 1 through 7 of the arrest the LES tone (mean +/- SD) decreased from 18.0 +/- 3.0 to 3.3 +/- 4.2. ROSC occurred in 10 of the 18 trials. In the 7 minutes after ROSC, LES pressure increased from 4.7 +/- 3.8 to 9.8 +/- 3.0. CONCLUSION: This study demonstrated a rapid and severe decrease in LES tone during prolonged cardiac arrest. When ROSC occurred, LES tension increased quickly but did not return to baseline.

Animals↗
PubMed1995

Effect of out-of-hospital defibrillation by basic life support providers on cardiac arrest mortality: a metaanalysis.

STUDY OBJECTIVE: Although some studies demonstrate otherwise, we hypothesized that metaanalysis would demonstrate a reduction in the relative risk of mortality when basic life support (BLS) providers can defibrillate out-of-hospital cardiac arrest patients. DESIGN: Metaanalysis of studies meeting the following criteria: single-tier or two-tier emergency medical service (EMS) system, survival to hospital discharge for patients in ventricular fibrillation, and manual and/or automatic external defibrillators. The alpha error rate was .05. RESULTS: Seven trials qualified for metaanalysis. Across all trials, the risk of mortality for BLS care with defibrillation versus that without was .915 (P = .0003). Separate subset analyses of single-tier and two-tier EMS systems demonstrated similar results. CONCLUSION: BLS defibrillation can reduce the relative risk of death for out-of-hospital cardiac arrest victims in ventricular fibrillation. Weaknesses in individual study designs and regional clustering limit the strength of this metaanalysis and conclusion.

Electric Countershock↗
PubMed1995

Evaluation of an end-tidal CO2 detector during cardiopulmonary resuscitation in a canine model for pediatric cardiac arrest.

Our objective was to evaluate a colorimetric end-tidal CO2 detector in a canine model for pediatric cardiac arrest. In a prospective unblinded study, cardiac arrest was induced in 11 anesthetized and paralyzed puppies, weighing 5.0 to 6.1 kg, by clamping the endotracheal tube (ETT) and discontinuing mechanical ventilation. During cardiopulmonary resuscitation (CPR), the detector and the capnometer were connected between the ETT and ventilator tubing. Color shades on the detector ranged from 1 (purple) to 6 (yellow) corresponding to increasing concentrations of CO2. End-tidal CO2 concentrations as indicated by detector color and capnometric reading were monitored and recorded throughout the study. The results showed that there was a significant correlation between the detector color score and capnometric readings (P < 0.001). A sudden rise in end-tidal CO2 indicated by both the capnometer and the detector occurred at return of spontaneous circulation (ROSC) in seven or < 1 minute before ROSC in four animals. This association was significant (P = 0.0009). We conclude that these results demonstrate that, in a canine model for pediatric cardiac arrest, the detector readings correlate with capnometry during CPR and indicate ROSC.

Animals↗
PubMed1995

Right lung ventilation in a porcine open-chest shock model.

OBJECTIVE: To determine the effect of selective right lung ventilation on gas exchange and hemodynamics when compared with bilateral lung ventilation in a porcine open-chest shock model. METHODS: A randomized, controlled laboratory investigation was performed using a static hemorrhagic shock model in 12 adult swine undergoing thoracotomy. The animals were subjected to a fixed 40% circulating blood volume hemorrhage over 20 minutes. Each animal was then assigned to either a tracheal (control) or a right mainstem (experimental) intubation group. Minute ventilation was held constant in both groups and tidal volumes were decreased by 33% in the right mainstem intubation group. Following intubation and left lateral thoracotomy, another 20% fixed-volume hemorrhage was instituted simultaneously with IV crystalloid and whole blood resuscitation for both groups over 30 minutes. Heart rate, blood pressure, and arterial blood gases were measured at 5-minute intervals. RESULTS: There was no significant difference between the control and experimental groups for any of the measured variables, including mean arterial pressure, pH, partial arterial pressure of CO2 (PaCO2), and PaO2, over time. All animals survived the study protocol. CONCLUSION: Selective right lung ventilation has no detrimental effect on gas exchange or hemodynamics when compared with standard bilateral lung ventilation in a porcine open-chest shock model.

Animals↗