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Objective:To explore the correlation between carotid blood flow and the parameters derived by pulse oximetry Plethysmographic waveform in cardiopulmonary resuscitation, so as to provide a new index for carotid blood flow monitoring in cardiopulmonary resuscitation.Methods:Seven male domestic pigs were utilized for cardiac arrest model through ventricular fibrillation induced by electrical stimulation. Eight minutes after cardiac arrest, artificial chest compression was given for 4 min, and epinephrine 20 μg/kg was injected intravenously at 2 min after chest compression. The compression frequency, compression depth, right carotid blood flow, pulse oximetry plethysmographic waveform, aortic pressure, right atrium pressure and end tidal carbon dioxide partial pressure were continuously monitored and recorded. From 30 s to 4 min after chest compression, the values of the mean right carotid blood flow, the area under curve (AUC) of pulse oximetry plethysmographic waveform, the mean perfusion index, the mean coronary perfusion pressure and the average end-tidal carbon dioxide partial pressure during 6 s before time point were calculated every 30 s. The correlations between right carotid blood flow and the AUC of pulse oximetry plethysmographic waveform and perfusion index were analyzed respectively.Results:Ventricular fibrillation was induced successfully in seven animals. There were no significant differences in the mean chest compression frequency and depth per min during 4 min of chest compression. Right carotid blood flow at 30 s after chest compression was (92.7±32.7) mL/min, and decreased to (48.5±23.5) mL/min at 1 min after chest compression ( P<0.05). There was no significant difference in blood flow before and after epinephrine injection ( P>0.05). The AUC of the blood oxygen plethysmographic waveform and perfusion index showed synchronous change trends with right carotid blood flow. Both coronary perfusion pressure and end-tidal carbon dioxide partial pressure showed different change trends with right carotid blood flow. There was a positive correlation between the right carotid blood flow and the AUC of blood oxygen plethysmographic waveform ( r=0.66, P<0.01), and also a positive correlation between right carotid blood flow and perfusion index ( r=0.57, P<0.01). Conclusions:Carotid blood flow is positively correlated with the AUC of blood oxygen plethysmographic waveform and perfusion index in a porcine model of cardiopulmonary resuscitation. Real-time monitoring of the two parameters derived by pulse oximetry plethysmographic waveform can reflect the changes of carotid blood flow to a certain extent.
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Objective To explore the timeliness value of cardiopulmonary resuscitation quality index (CQI) in patients' prognostic evaluation during cardiopulmonary resuscitation (CPR).Methods A prospective descriptive study was conducted.According to whether they got return of spontaneously circulation (ROSC) or not,45 patients receiving CPR were divided into the ROSC group and non-ROSC group.The changes of CQI and partial pressure of end-tidal carbon dioxide (PETCO2) during CPR were collected,and were analyzed to valuate the prognosis of patients.Results The initial,end,and average PETCO2 were statistically different between the ROSC group and the non-ROSC group [7.0(3.6,14.6) vs 7.0(3.6,14.6) mmHg;29.5(19.8,35.9) vs 4.0(2.3,10.2)mmHg;and 22.2(11.8,36.3) vs 4.0(2.5,9.0) mmHg,respectively;P＜0.05],and the end CQI was statistically different between the two groups (59.6±8.9 vs 34.8±5.2,P＜0.05).The CQI differences between the two groups initiated at 11 min after CPR,and stopped at 29 min after CPR.The optimal cut-offpoint of terminal CQI and PETCO2 for prognostic was 33.2 and 16.1 mmHg respectively,and there was a statistically difference in the area under the curve between them (P＜0.05).Conclusions During CPR,both CQI and PETCO2 can be used to evaluate the prognosis,and CQI is more capable of predicting in the late stage of CPR.
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ObjectiveTo investigate the feasibility of using pulse oximetry plethysmographic waveform (POP) to identify the restoration of spontaneous circulation (ROSC) during cardiopulmonary resuscitation (CPR).Methods An observational research was conducted. A porcine model of ventricular fibrillation (VF) arrest was reproduced. After 3 minutes of untreated VF, animals received CPR according to the latest CPR guidelines, providing chest compressions to a depth of 5 cm with a rate of 105 compressions per minute and instantaneous mechanical ventilation. After 2 minutes of CPR, animals were defibrillated with 100 J biphasic, followed by continuous chest compressions. Data of hemodynamic parameters, partial pressure of end-tidal carbon dioxide (PETCO2) and POP were collected. The change in POP was observed, and the characteristics of changes of the waves were recorded during the peri-CPR period using the time and frequency domain methods.Results VF was successfully induced in 6 pigs, except 1 death in anesthesia induction period.① After VF, invasive blood pressure waveform and POP of the animals disappeared. PETCO2 was (18.83±2.71) mmHg (1 mmHg=0.133 kPa), and diastolic arterial pressure was (23.83±5.49) mmHg in compression stage. Animals attained ROSC within 1 minute after defibrillation, with PETCO2 [(51.83±9.35) mmHg] and diastolic arterial pressure [(100.67±10.97) mmHg] elevated significantly compared with that of compression stage (t1 = 8.737,t2 = 25.860, bothP = 0.000), with appearance of arterial blood pressure waveform.② Characteristic changes in POP were found in all experimental animals. During the stages of induced VF, compression, ROSC, and compression termination, POP showed characteristic waveform changes. POP showed disappearance of waveform, regular compression wave, fluctuation hybrid and stable pulse wave in time domain method; while in the frequency domain method waveform disappearance, single peak of compression, double or fusion peak and single peak of pulse were observed.Conclusion Analysis of POP using time and frequency domain methods could not only quickly detect cardiac arrest, but also show a role as a feasible, non-invasive marker of ROSC during CPR.
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PURPOSE: It is difficult to predict volume responsiveness in hemodynamically unstable patients with spontaneous breathing activity. Our objective was to test whether the respiratory variations in pulse oximetry plethysmography (POP) waveform amplitude could predict fluid responsiveness to fluid resuscitation (FR) in spontaneously breathing adult shock patients. METHODS: We investigated 21 patients presenting with shock in the Emergency Room. We assessed hemodynamic status and calculated the respiratory variations in POP waveform amplitude before and after FR. Heart rate, blood pressures (MAP, SBP), maximal POP (POPmax), minimal POP (POPmin) and deltaPOP, defined as deltaPOP = (POPmax - POPmin) / ([POPmax + POPmin] / 2) were recorded. We measured hemodynamic parameters by doppler ultrasound, USCOM(R). RESULTS: Comparisons of hemodynamic parameters between before and after FR showed no significant difference in heart rate, but POP showed significant differences in changes in SBP, MAP, cardiac index, stroke volume index and respiratory variations. In response group(> or =15% in delta CI), the change in cardiac index, stroke volume index, and the respiratory variation in the POP were not significantly different. CONCLUSION: In spontaneously breathing patients with shock, we suggest that delta POP is not a reliable parameter in the prediction of fluid responsiveness.
Subject(s)
Adult , Humans , Emergencies , Heart Rate , Hemodynamics , Oximetry , Plethysmography , Respiration , Resuscitation , Shock , Stroke VolumeABSTRACT
BACKGROUND: In hemodynamically unstable patients with spontaneous breathing activity, predicting volume responsivenss is a difficult challenge. Our objective was to test whether the respiratory changes in pulse oxymetry plethysmographic waveform amplitude (POP) and in stroke volume (deltaSV) could predict fluid responsiveness to passive leg raising (PLR) in normal volunteers. METHODS: We investigated 25 normal volunteers. We assessed hemodynamic status (HR, SBP, MAP, CI and SVI) and calculated the respiratory variation in pulse oximetry plethysmographic waveform amplitude at supine and after PLR. We attached a pulse oximeter of 25 spontaneously breathing volunteers as several time points: after 1 min and 5 min in supine position and during PLR at 60degrees. Heart rate, non-invasive blood pressures (mean arterial pressure, systolic blood pressure), maximal POP (POPmax), minimal POP (POPmin) and deltaPOP defined as (POPmax-POPmin)/[(POPmax+POPmin)/2] were recorded using monitor. RESULTS: Comparing to supine and PLR, systolic blood pressure and mean arterial pressure were not different, but the change in cardiac index, stroke volume and respiratory variation in POP were significant different. In response group (> or =10% in deltaCI), the change in cardiac index, stroke volume and respiratory variation in POP were significant greater. CONCLUSION: PLR induces a significant decrement of variation in POP amplitude among spontaneouely breathing volunteers. We suppose that the changes in stroke volume and the respiratory variation in pulse oximetry plethysmographic waveform amplitude induced by PLR predict fluid responsiveness in spontaneous breathing patients.