Abdominal oxygen saturation for monitoring return of spontaneous circulation in out-of-hospital cardiac arrest using near infrared spectrophometry

Skeletal muscle oxygenation during cardiopulmonary resuscitation as a predictor of return of spontaneous circulation: a pilot study

BACKGROUND

Near-infrared spectroscopy (NIRS) provides regional tissue oxygenation (rSO2) even in pulseless states, such as out-of-hospital cardiac arrest (OHCA). Brain rSO2 seems to be important predictor of return of spontaneous circulation (ROSC) during cardiopulmonary resuscitation (CPR). Aim of our study was to explore feasibility for monitoring and detecting changes of skeletal muscle rSO2 during resuscitation.

METHODS

Skeletal muscle and brain rSO2 were measured by NIRS (SenSmart Model X-100, Nonin, USA) during CPR in adult patient with OHCA. Start (basal) rSO2, maximal during CPR (maximal) and difference between maximal-minimal rSO2 (delta-rSO2), were recorded. Patients were divided into ROSC and NO-ROSC group.

RESULTS

20 patients [age: 66.0ys (60.5-79.5), 65% male] with OHCA [50% witnessed, 70% BLS, time to ALS 13.5 min (11.0-19.0)] were finally analyzed. ROSC was confirmed in 5 (25%) patients. Basal and maximal skeletal muscle rSO2 were higher in ROSC compared to NO-ROSC group [49.0% (39.7-53.7) vs. 15.0% (12.0-25.2), P =  0.006; 76.0% (52.7-80.5) vs. 34.0% (18.0-49.5), P =  0.005, respectively]. There was non-linear cubic relationship between time of collapse and basal skeletal muscle rSO2 in witnessed OHCA and without BLS (F-ratio = 9.7713, P =  0.0261). There was correlation between maximal skeletal muscle and brain rSO2 (n = 18, rho: 0.578, P =   0.0121).

CONCLUSIONS

Recording of skeletal muscle rSO2 during CPR in patients with OHCA is feasible. Basal and maximal skeletal muscle rSO2 were higher in ROSC compared to NO-ROSC group. Clinical trial registration number ClinicalTrials.gov, NCT04058925, registered on: 16th August 2019. URL of trial registry record: https://www.

CLINICALTRIALS

gov/ct2/show/NCT04058925?titles=Tissue+Oxygenation+During+Cardiopulmonary+Resuscitation+as+a+Predictor+of+Return+of+Spontaneous+Circulation&draw=2&rank=1 .

Continuous monitoring of brain perfusion by cerebral oximetry after spontaneous return of circulation in cardiac arrest: a case report

BACKGROUND

Cerebral resuscitation determines the prognosis for patients who have experienced sudden death, and brain protection is the focus of clinical treatment. Cerebral resuscitation depends on the timing and quality of cardiopulmonary resuscitation (CPR). At present, cerebral oxygen monitoring is used mainly to monitor the quality of external cardiac compression and provide a prognosis for the nervous system. However, after the return of autonomous circulation, it is necessary to conduct continuous monitoring to ensure measures are taken timeously since hemodynamic instability, brain edema, and other factors may cause occult brain injury, and invasive arterial pressure cannot represent cerebral perfusion.

CASE PRESENTATION

By using continuous cerebral oxygen monitoring after CPR and the return of spontaneous circulation, a patient who was witnessed to have experienced sudden death in the hospital was found to have insufficient cerebral perfusion; he underwent timely intra-aortic balloon counterpulsation to improve his hemodynamics and cerebral perfusion. The patient went on to achieve a good neurological prognosis.

CONCLUSION

Cerebral oxygen monitoring should be conducted throughout the treatment period; physicians should understand cerebral perfusion in real time and implement timely intervention measures to reduce occult brain injury and improve the neurological prognosis of patients.

Regional cerebral oxygen saturation during cardiopulmonary resuscitation as a predictor of return of spontaneous circulation and favourable neurological outcome - A review of the current literature

INTRODUCTION

Regional cerebral oxygen saturation (rSO2) can be measured non-invasively even at no- or low-flow states. It thus allows assessment of brain oxygenation during CPR. Certain rSO2 values had been associated with return of spontaneous circulation (ROSC) and neurological outcome in the past. Clear-cut thresholds for the prediction of beneficial outcome, however, are still lacking.

METHODS

We conducted a database search to extract all available investigations on rSO2 measurement during CPR. Mean, median, and ΔrSO2 values were either taken from the studies or calculated. Thresholds for the outcome "ROSC" and "neurological outcome" were sought.

RESULTS

We retrieved 26 publications for the final review. The averaged mean rSO2 for patients achieving ROSC was 41 ± 12% vs. 30 ± 12% for non-ROSC (p = .009). ROSC was not observed when mean rSO2 remained <26%. In ROSC patients, ΔrSO2 was 22 ± 16% vs. 7 ± 10% in non-ROSC patients (p = .009). A rSO2 threshold of 36% predicted ROSC with a sensitivity of 67% and specificity of 69% while ΔrSO2 of 7% showed a sensitivity of 100% and a specificity of 86% (AUC = 0.733 and 0.893, respectively). Mean rSO2 of 47 ± 11% was associated with favourable and 38 ± 12% with poor neurological outcome. There was, however, a great overlap between groups due to scarce data.

CONCLUSION

Higher rSO2 consistently correlated with increased rates of ROSC. The discriminatory power of rSO2 to prognosticate favourable neurological outcome remains unclear. Measuring rSO2 during CPR could potentially facilitate clinical decision-making.

An efficient optimization method to improve the measuring accuracy of oxygen saturation by using triangular wave optical signal

The oxygen saturation is one of the important parameters to evaluate human health. This paper presents an efficient optimization method that can improve the accuracy of oxygen saturation measurement, which employs an optical frequency division triangular wave signal as the excitation signal to obtain dynamic spectrum and calculate oxygen saturation. In comparison to the traditional method measured RMSE (root mean square error) of SpO₂ which is 0.1705, this proposed method significantly reduced the measured RMSE which is 0.0965. It is notable that the accuracy of oxygen saturation measurement has been improved significantly. The method can simplify the circuit and bring down the demand of elements. Furthermore, it has a great reference value on improving the signal to noise ratio of other physiological signals.

Review of splanchnic oximetry in clinical medicine

Global tissue perfusion and oxygenation are important indicators of physiologic function in humans. The monitoring of splanchnic oximetry through the use of near-infrared spectroscopy (NIRS) is an emerging method used to assess tissue oxygenation status. Splanchnic tissue oxygenation (SrSO2) is thought to be potentially of high value in critically ill patients because gastrointestinal organs can often be the first to suffer ischemic injury. During conditions of hypovolemia, cardiac dysfunction, or decreased oxygen-carrying capacity, blood flow is diverted toward vital organs, such as the brain and the heart at the expense of the splanchnic circulation. While monitoring SrSO2 has great potential benefit, there are limitations to the technology and techniques. SrSO2 has been found to have a relatively high degree of variability that can potentially make it difficult to interpret. In addition, because splanchnic organs only lie near the skin surface in children and infants, and energy from currently available sensors only penetrates a few centimeters deep, it can be difficult to use clinically in a noninvasive manner in adults. Research thus far is showing that splanchnic oximetry holds great promise in the ability to monitor patient oxygenation status and detect disease states in humans, especially in pediatric populations.

Near-infrared Spectroscopy Monitoring During Cardiac Arrest: A Systematic Review and Meta-analysis

BACKGROUND

Tissue oximetry using near-infrared spectroscopy (NIRS) is a noninvasive monitor of cerebral oxygenation. This new technology has been used during cardiac arrest (CA) because of its ability to give measures in low-blood-flow situations. The aim of this study was to assess the evidence regarding the association between the types of NIRS measurements (mean, initial, and highest values) and resuscitation outcomes (return of spontaneous circulation [ROSC], survival to discharge, and good neurologic outcome) in patients undergoing cardiopulmonary resuscitation.

METHODS

This review was registered (Prospero CRD42015017380) and is reported as per the PRISMA guidelines. Medline, Embase, and CENTRAL were searched. All studies, except case reports and case series of fewer than five patients, reporting on adults that had NIRS monitoring during CA were eligible for inclusion. Two reviewers assessed the quality of the included articles and extracted the data. The outcome effect was standardized using standardized mean difference (SMD).

RESULTS

Twenty nonrandomized observational studies (15 articles and five conference abstracts) were included in this review, for a total of 2,436 patients. We found a stronger association between ROSC and mean NIRS values (SMD = 1.33; 95% confidence interval [CI] = 0.92 to 1.74) than between ROSC and initial NIRS measurements (SMD = 0.51; 95% CI = 0.23 to 0.78). There was too much heterogeneity among the highest NIRS measurements group to perform meta-analysis. Only two of the 75 patients who experienced ROSC had a mean NIRS saturation under 30%. Patients who survived to discharge and who had good neurologic outcome displayed superior combined initial and mean NIRS values than their counterparts (SMD = 1.63; 95% CI = 1.34 to 1.92; and SMD = 2.12; 95% CI = 1.14 to 3.10).

CONCLUSIONS

Patients with good resuscitation outcomes have significantly higher NIRS saturations during resuscitation than their counterparts. The types of NIRS measurements during resuscitation influenced the association between ROSC and NIRS saturation. Prolonged failure to obtain a NIRS saturation higher than 30% may be included in a multimodal approach to the decision of terminating resuscitation efforts (Class IIb, Level of Evidence C-Limited Data).