Tissue Oxygen Monitoring Research Articles

Assessing the Impact of 3% Hypertonic Saline Hyperosmolar Therapy on Intubated Children With Isolated Traumatic Brain Injury by Cerebral Oximetry in a Pediatric Emergency Setting.

BACKGROUND Intubated pediatric patients with isolated traumatic brain injury (TBI) are a diagnostic challenge for early detection of altered cerebral physiology instigated by trauma-induced increased intracranial pressure (ICP) while preventing secondary neuronal damage (secondary insult detection) and assessing the effects of increased ICP therapeutic interventions (3% hypertonic saline [HTS]). Invasive brain tissue oxygen monitoring is guiding new intensive care unit TBI management but is not pediatric emergency department (PED) readily accessible. Objective measurements on pediatric isolated TBI-altered bihemispheric cerebral physiology and treatment effects of 3% HTS are currently lacking. Cerebral oximetry can assess increased ICP-induced abnormal bihemispheric cerebral physiology by measuring regional tissue oxygenation (rcSO2) and cerebral blood volume index (CBVI) and the mechanical cerebrospinal fluid removal effects on the increased ICP-induced abnormal bihemispheric cerebral physiology.In the PED intubated patients with isolated TBI, assessing the 3% HTS therapeutic response is solely by vital signs and limited clinical assessment skills. Objective measurements of the 3% HTS hyperosmolar effects on the PED isolated TBI patients' altered bihemispheric cerebral physiology are lacking. We believe that bihemispheric rcSO2 and CBVI could elucidate similar data on 3% HTS impact and influence in the intubated isolated TBI patients. OBJECTIVE This study aimed to analyze the effects of 3% HTS on bihemispheric rcSO2 and CBVI in intubated patients with isolated TBI. METHODS An observational, retrospective analysis of bihemispheric rcSO2 and CBVI readings in intubated pediatric patients with isolated TBI receiving 3% HTS infusions, was performed. RESULTS From 2010 to 2017, 207 intubated patients with isolated TBI received 3% HTS infusions (median age, 2.9 [1.1-6.9 years]; preintubation Glasgow Coma Scale score, 7 [6-8]). The results were as follows: initial pre-3% HTS, 43% (39.5% to 47.5%; left) and 38% (35% to 42%; right) for rcSO2 80%, and 16.5 (6 to 33, P 80%, and 16.5 (6 to 33, P 10 showed rcSO2 10 and required the greatest number of 3% HTS infusions. For 3% HTS 15% rcSO2 change time effect, all patients achieved positive change with subdural hematomas and hemispheric rcSO2 readings 10 demonstrated the greatest significant positive delta change and required the greatest numbers of 3% HTS infusions. Overall, 3% HTS produced a significant positive 15% change within 2.1 minutes of infusion, whereas heart rate showed no significant change. During trauma neuroresuscitation, especially in intubated isolated TBI patients requiring 3% HTS, cerebral oximetry has shown its functionality as a rapid adjunct neurological, therapeutic assessment tool and should be considered in the initial emergency department pediatric trauma neurological assessment and neuroresuscitation regimen.

IRIS: A Modular Platform for Continuous Monitoring and Caretaker Notification in the Intensive Care Unit.

New approaches are needed to interpret large amounts of physiologic data continuously recorded in the ICU. We developed and prospectively validated a versatile platform (IRIS) for real-time ICU physiologic monitoring, clinical decision making, and caretaker notification. IRIS was implemented in the neurointensive care unit to stream multimodal time series data, including EEG, intracranial pressure (ICP), and brain tissue oxygenation (PbtO2), from ICU monitors to an analysis server. IRIS was applied for 364 patients undergoing continuous EEG, 26 patients undergoing burst suppression monitoring, and four patients undergoing intracranial pressure and brain tissue oxygen monitoring. Custom algorithms were used to identify periods of elevated ICP, compute burst suppression ratios (BSRs), and detect faulty or disconnected EEG electrodes. Hospital staff were notified of clinically relevant events using our secure API to route alerts through a password-protected smartphone application. Sustained increases in ICP and concordant decreases in PbtO2 were reliably detected using user-defined thresholds and alert throttling. BSR trends computed by the platform correlated highly with manual neurologist markings (r20.633-0.781; p < 0.0001). The platform identified EEG electrodes with poor signal quality with 95% positive predictive value, and reduced latency of technician response by 93%. This study validates a flexible real-time platform for monitoring and interpreting ICU data and notifying caretakers of actionable results, with potential to reduce the manual burden of continuous monitoring services on care providers. This work represents an important step toward facilitating translational medical data analytics to improve patient care and reduce health care costs.

The effects of ozone on the acute phase of intestinal ischemia-reperfusion injury in rats.

In this study, we aimed to examine the therapeutic effects of ozone on the acute phase of intestinal ischemia-reperfusion (I/R) injury in rats to resemble clinical practice. Eighteen Wistar albino rats were assigned to control (CG, n=6), sham (SG, n=6) and ozone groups (OG, n=6). A midline laparotomy was performed and a superior mesenteric artery (SMA) in the SG and OG was occluded with a 0/0 catgut suture, but in the CG, the incision was closed without any intervention. Tissue oxygenation was monitored with a tissue oxygenation monitor to achieve the same grade during intestinal ischemia. The incision was closed and, in the OG, ozone/oxygen mixture (0.7 mg/kg) was injected intraperitoneally, 20 minutes before reperfusion. Surgical incision was reopened and reperfusion was achieved after 60 minutes of ischemia in the SG and OG. After 60 minutes of reperfusion, 2 cm small intestine segment was sampled for histopathological assessment of the intestinal mucosal damage (Chiu score) and biochemical assessment of oxidative stress markers (nitric oxide: NO, malondialdehyde: MDA, superoxide dismutase: SOD) in all groups. The Chiu scores of the SG and OG were statistically increased than that of the CG (p=0.002; and p=0.002, respectively). Chiu score in the OG was higher compared to that in the SG, but not statistically significant (p=0.175). MDA levels were statistically higher in the SG and OG than that of the CG (p=0.004; and p=0.010, respectively). However, the difference between the SG and OG was not statistically significant (p=0.522). SOD and NO levels were not significantly different between groups (p=0.451 and p=0.056, respectively). Contrary to the literature, single-dose ozone therapy did not reduce the oxidative stress or improve the ischemic damage in intestinal I/R injury in rats. Further evaluation with different doses in different time periods is needed for potential clinical use.

Prognostic Value of Tissue Oxygen Monitoring and Regional Cerebral Oxygen Saturation Monitoring and Their Correlation in Neurological Patients with Sepsis: A Preliminary, Prospective, Observational Study.

There is paucity of literature on the prognostic value of tissue oxygen saturation (StO2) and regional cerebral oxygen saturation (rSO2) in neurological patients with sepsis. In this preliminary study, we investigated the prognostic value of StO2 and rSO2 in a group of neurological patients and correlated StO2 and rSO2 with hemodynamic and metabolic parameters. This preliminary, prospective observational study was conducted in 45 adult neurological patients admitted to intensive care unit. Once a diagnosis of sepsis or septic shock was established, parameters of oxygenation (StO2, rSO2, central venous oxygen saturation [ScvO2]), serum lactate, illness severity scores (Acute Physiology and Chronic Health Evaluation score, Sequential Organ Failure Assessment score, Glasgow Coma Scale) were recorded at 0, 6, 12, 24, 36, and 48 hours, and once daily thereafter. Outcomes were in-hospital mortality attributable to sepsis and the Glasgow outcome score at hospital discharge. There was a moderately positive correlation between StO2 and rSO2 at baseline (r=0.599; P=0.001). StO2, illness severity scores and serum lactate, but not rSO2, were significantly different between survivors (n=29) and nonsurvivors (n=16) at baseline and during the first 48 hours. An rSO2 of 62.5% had a sensitivity of 83% and specificity of 67% to differentiate survivors and nonsurvivors of septic shock at 48 hours. StO2 had a higher correlation with ScvO2 and serum lactate than rSO2. StO2 prognosticates survival and favorable/unfavorable outcomes in neurological patients with sepsis. The role of rSO2 in predicting survival in milder form of sepsis is doubtful.

International consensus on the monitoring of cerebral oxygen tissue pressure in neurocritical patients.

Continuous monitoring of cerebral oxygenation and its application to the management of the severe neurological patient is a challenge for the management of patients with acute critical brain damage. Although several techniques have been described for monitoring brain, brain tissue oxygen monitoring provides relevant information about oxygen levels of brain tissue. However, the development of this technique has been associated with the need to answer not only some technical aspects of it as well as the meaning of the changes of the cerebral oxygenation in the neurocritical patient. The consensus document responds to various questions related to the monitoring of cerebral oxygenation by means of a cerebral oxygen tissue pressure sensor. For this purpose, a list of questions was prepared and a reviewed of the medical literature was made. The quality of the evidence and the degree of recommendation was evaluated using the GRADE methodology.

International consensus on the monitoring of cerebral oxygen tissue pressure in neurocritical patients

Continuous monitoring of cerebral oxygenation and its application to the management of the severe neurological patient is a challenge for the management of patients with acute critical brain damage. Although several techniques have been described for monitoring brain, brain tissue oxygen monitoring provides relevant information about oxygen levels of brain tissue. However, the development of this technique has been associated with the need to answer not only some technical aspects of it as well as the meaning of the changes of the cerebral oxygenation in the neurocritical patient. The consensus document responds to various questions related to the monitoring of cerebral oxygenation by means of a cerebral oxygen tissue pressure sensor. For this purpose, a list of questions was prepared and a reviewed of the medical literature was made. The quality of the evidence and the degree of recommendation was evaluated using the GRADE methodology.

Towards Skin Tissue Oxygen Monitoring: An Investigation of Optimal Visible Spectral Range and Minimal Spectral Resolution

This paper investigated the minimum spectral resolution and optimal spectra range for optical monitoring of skin blood oxygen saturation (StO2). For this purpose, this study recruited fourteen Asian volunteers for demonstration work. The performed measurements included reflectance information collected from the recruits during at rest and after a pressure of 140 mmHg was applied on their upper right arm. The prediction of the required value was via analysis of data of the considered visible ranges of 500 – 660 nm, 520 – 645 nm, 520 – 600 nm, and 530 – 570 nm, with sampling resolutions of 1 nm, 2 nm, 5 nm, and 10 nm. The offline data analysis using Extended Modified Lambert Beer model revealed that the StO2 value predicted using spectral data in the range 530 – 570 nm showed considerable similarity with that obtained from 520 – 645 nm range at spectral resolutions of up to 5 nm. The mean and standard deviation of the differences in the values obtained from these spectral ranges in the case of 5 nm sampling is given by 7 ± 8.6 % and 14 ± 3.2 % for at rest and blood occlusion experiment, respectively. The higher variability in the value predicted for the latter experiment is likely due to insufficiency of the employed technique to extricate the distinctive features in hemoglobin spectra using the corresponding resolution. The findings of this study may be useful as a guide to facilitate in the design of multispectral imaging system for optical monitoring of one’s StO2 with high speed.

Multimodality monitoring in neurocritical care

Monitoring the health of an injured brain is essential to forewarn neurological worsening and to gain insight into the pathophysiology of a complex disorder.Clinical examination remains a cornerstone in monitoring patients with brain injury. The Glasgow coma score (GCS) is widely used but lacks information regarding brain stem functions like pupillary reaction and shows moderate inter-observer reliability. However, despite these shortcomings, GCS remains a robust indicator of the need for surgery and prognosis after cardiac arrest, hypoxic brain injury, and posterior circulation stroke. A new scoring system called Full Outline of Unresponsiveness has been proposed and shows excellent inter-observer reliability and includes points concerning brain stem functions.1 The most commonly used monitoring modality is intracranial pressure (ICP) monitoring. ICP shows threshold physiology where the outcome of the patients changes after a threshold of 20 to 25 mmHg. Refractory ICP is a good predictor of mortality but not of the functional outcome after traumatic brain injury.Brain injury causes varying degrees of disruption to cerebral blood flow and its autoregulation. Studying autoregulation provides a useful strategy for targeting cerebral perfusion pressure close to the autoregulatory range. Transcranial Doppler and ICMplus (Intensive Care Monitoring) are used to study autoregulation. ICMplus is a software-based tool that studies the correlation between slow changes in mean arterial pressure and ICP to evaluate the state of autoregulation throughout the duration of ICP monitoring.2 Brain tissue oxygen measures the partial pressure of oxygen in the extracellular fluid of the neural tissue. Reduction in brain tissue oxygen is a marker of cellular distress. A phase 2 trial on brain tissue oxygen monitoring demonstrated the safety and feasibility of the protocol-based management of brain tissue oxygenation and ICP, and a trend towards lower mortality and improved functional outcome in patients treated with combined oxygen and ICP protocol.3 Microdialysis is a point of care test that monitors substrate delivery and metabolism at the cellular level. The lactate-pyruvate (LP) ratio is an indicator of the redox state of cells and a high LP ratio is associated with an unfavourable outcome.4 The electroencephalogram (EEG) is used in critical care for monitoring sedation and diagnosis of seizure activity. EEG is a complex signal which requires advanced training and skills for interpretation. Novel EEG-based monitors are aimed at simplifying the signal for straightforward interpretation by bedside medical professionals. Cerebral function monitor (CFM) is a compressed single channel amplitude integrated EEG monitor mainly used for the detection of status epilepticus and burst suppression during thiopentone infusion. A novel technique that uses direct electrodes applied on the cortical surface called Electrocorticogram (ECoG) shows spreading depolarisations on the cortical surface that are caused by loss of ionic homeostasis and substrate delivery.5 These depolarisations are a sensitive indicator of impending neuronal death and may serve as a target for novel mechanistically oriented therapies.Detection, prevention, and monitoring of secondary cerebral insults that alter the prognosis from the injury, remains at the centre stage in neurocritical care. In the future, integrated informatics derived from multimodality monitoring will play a pivotal role in clinical decision algorithms.

Can molecular markers of oxygen homeostasis and the measurement of tissue oxygen be leveraged to optimize red blood cell transfusions?

The clinical indication for transfusing red blood cells (RBCs) is to restore or maintain adequate oxygenation of respiring tissue. Oxygen (O2) transport, delivery, and utilization following transfusion are impacted by perfusion, hemoglobin (Hb) allosteric saturation/desaturation, and the concentration of tissue O2. Bioavailable O2 maintains tissue utilization and homeostasis; therefore, measuring imbalances in supply and demand could be valuable to assessing blood quality and transfusion effectiveness. O2 homeostasis is critically intertwined with erythropoietic response in blood loss and anemia and the hormones that modulate iron mobilization and RBC production (e.g., erythropoietin, erythroferrone, and hepcidin) are intriguing markers for the monitoring of transfusion effectiveness in acute and chronic settings. The evaluation of RBC donor unit quality and the determination of RBC transfusion needs are emerging areas for biomarker development and minimally invasive O2 measurements. Novel methods for assessing circulatory and tissue compartment biomarkers of transfusion effectiveness are suggested. In addition, monitoring of tissue oxygenation by indirect and direct measurements of O2 is available and applied in experimental settings. Herein, we discuss tissue O2 homeostasis, related aspects of erythropoiesis, molecular markers and measurements of tissue oxygenation, all aimed at optimizing transfusion and assessing blood quality.

Agreement between frontal and occipital regional cerebral oxygen saturation in infants during surgery and general anesthesia an observational study.

Advances in perioperative pediatric care have resulted in an increased number of procedures requiring anesthesia. During anesthesia and surgery, the patient is subjected to factors that affect the circulatory homeostasis, which can influence oxygenation of the brain. Near-infrared spectroscopy (NIRS) is an easy applicable noninvasive method for monitoring of regional tissue oxygenation (rScO₂%). Alternate placements for NIRS have been investigated; however, no alternative cranial placements have been explored. To evaluate the agreement between frontal and occipital recordings of rScO₂% in infants using INVOSTM during surgery and general anesthesia. A standard frontal monitoring of rScO₂% with NIRS was compared with occipital rScO₂% measurements in fifteen children at an age <1year, ASA 1-2, undergoing cleft lip and/or palate surgery during general anesthesia with sevoflurane. An agreement analysis was performed according to Bland and Altman. Mean values of frontal and occipital rScO₂% at baseline were largely similar (70.7±4.77% and 69.40±5.04%, respectively). In the majority of the patients, the frontal and occipital recordings of rScO2 changed in parallel. There was a moderate positive correlation between frontal and occipital rScO₂% INVOS™ readings (rho[ρ]: 0.513, P<.01). The difference between frontal and occipital rScO₂ ranged from -31 to 28 with a mean difference (bias) of -0.15%. The 95% limit of agreement was -18.04%-17.74%. The error between frontal and occipital rScO₂ recordings was 23%. The agreement between frontal and occipital recordings of brain rScO₂% in infants using INVOSTM during surgery and general anesthesia was acceptable. In surgical procedures where the frontal region of the head is not available for monitoring, occipital recordings of rScO₂% could be an option for monitoring.

Review of early development of near-infrared spectroscopy and recent advancement of studies on muscle oxygenation and oxidative metabolism

Near-infrared spectroscopy (NIRS) has become an increasingly valuable tool to monitor tissue oxygenation (Toxy) in vivo. Observations of changes in the absorption of light with Toxy have been recognized as early as 1876, leading to a milestone NIRS paper by Jöbsis in 1977. Changes in the absorption and scatting of light in the 700-850-nm range has been successfully used to evaluate Toxy. The most practical devices use continuous-wave light providing relative values of Toxy. Phase-modulated or pulsed light can monitor both absorption and scattering providing more accurate signals. NIRS provides excellent time resolution (~ 10Hz), and multiple source-detector pairs can be used to provide low-resolution imaging. NIRS has been applied to a wide range of populations. Continued development of NIRS devices in terms of lower cost, better detection of both absorption and scattering, and smaller size will lead to a promising future for NIRS studies.

Machine Perfusion of Liver Grafts With Implantable Oxygen Biosensors: Proof of Concept Study in a Rodent Model.

Background.Normothermic machine perfusion (NMP) is emerging as a novel preservation strategy in liver transplantation, but the optimal methods for assessing liver grafts during this period have not been determined. The aim of this study was to investigate whether implantable oxygen biosensors can be used to monitor tissue oxygen tension in liver grafts undergoing NMP.Methods.Implantable phosphorescence-based oxygen sensors were tested in 3 different experimental groups: (1) in vivo during laparotomy, (2) during NMP of liver grafts with an acellular perfusate (NMP-acellular), and (3) during NMP with perfusate containing red blood cells (NMP-RBC). During in vivo experiments, intrahepatic oxygen tension was measured before and after occlusion of the portal vein (PV). In NMP experiments, intrahepatic oxygen tension was measured as a function of different PV pressure settings (3 vs 5 vs 8 mm Hg) and inflow oxygen concentration (95% O2 vs 6% O2).Results.In vivo, intrahepatic oxygen tension decreased significantly within 2 minutes of clamping the PV (P < 0.05). In NMP experiments, intrahepatic oxygen tension correlated directly with PV pressure when high inflow oxygen concentration (95%) was used. Intrahepatic oxygen tension was significantly higher in the NMP-RBC group compared with the NMP-acellular group for all conditions tested (P < 0.05).Conclusions.Implantable oxygen biosensors have potential utility as a tool for real-time monitoring of intrahepatic oxygen tension during NMP of liver grafts. Further investigation is required to determine how intrahepatic oxygen tension during NMP correlates with posttransplant graft function.

Regional tissue oxygenation monitoring in the neonatal intensive care unit: evidence for clinical strategies and future directions.

Near-infrared spectroscopy (NIRS)-based monitoring of regional tissue oxygenation (rSO2) is becoming more commonplace in the neonatal intensive care unit (NICU). While increasing evidence supports rSO2 monitoring, actual standards for applying this noninvasive bedside technique continue to evolve. This review highlights the current strengths and pitfalls surrounding practical NIRS-based monitoring in the neonatal population. The physiologic background of rSO2 monitoring is discussed, with attention to understanding oxygen delivery/consumption mismatch and its effects on tissue oxygen extraction. The bedside utility of both cerebral and peripheral rSO2 monitoring in the NICU is then explored from two perspectives: (1) disease/event-specific "responsive" monitoring and (2) "routine," continuous monitoring. Recent evidence incorporating both monitoring approaches is summarized with emphasis on practical applicability in the NICU. Finally, a future paradigm for a broad-based NIRS monitoring strategy is presented, with attention towards improving personalization of neonatal care and ultimately enhancing long-term outcomes.

Observations on the Cerebral Effects of Refractory Intracranial Hypertension After Severe Traumatic Brain Injury

BackgroundRaised intracranial pressure (ICP) is a prominent cause of morbidity and mortality after severe traumatic brain injury (TBI). However, in the clinical setting, little is known about the cerebral physiological response to severe and prolonged increases in ICP.MethodsThirty-three severe TBI patients from a single center who developed severe refractory intracranial hypertension (ICP > 40 mm Hg for longer than 1 h) with ICP, arterial blood pressure, and brain tissue oxygenation (PBTO2) monitoring (subcohort, n = 9) were selected for retrospective review. Secondary parameters reflecting autoregulation (including pressure reactivity index—PRx, which was available in 24 cases), cerebrospinal compensatory reserve (RAP), and ICP pulse amplitude were calculated.ResultsPRx deteriorated from 0.06 ± 0.26 a.u. at baseline levels of ICP to 0.57 ± 0.24 a.u. (p < 0.0001) at high levels of ICP (> 50 mm Hg). In 4 cases, PRx was impaired (> 0.25 a.u.) before ICP was raised above 25 mm Hg. Concurrently, PBTO2 decreased from 27.3 ± 7.32 mm Hg at baseline ICP to 12.68 ± 7.09 mm Hg at high levels of ICP (p < 0.001). The pulse amplitude of the ICP waveform increased with increasing ICP but showed an ‘upper breakpoint’—whereby further increases in ICP lead to decreases in pulse amplitude—in 6 out of the 33 patients.DiscussionSevere intracranial hypertension after TBI leads to decreased brain oxygenation, impaired pressure reactivity, and changes in the pulse amplitude of ICP. Impaired pressure reactivity may denote increased risk of developing refractory intracranial hypertension in some patients.

Surrogate of Adequate Perfusion: Bladder Tissue Oxygen Monitoring

Surrogate of Adequate Perfusion: Bladder Tissue Oxygen Monitoring

Predictive Value of Sublingual Microcirculation and Peripheral Tissue Oxygen Monitoring

Predictive Value of Sublingual Microcirculation and Peripheral Tissue Oxygen Monitoring

Incremental value of noncerebral somatic tissue oxygenation monitoring for patients undergoing surgery.

There is increasing interest in the use of noncerebral somatic tissue oxygen saturation (SstO2) monitoring on the basis of near-infrared spectroscopy in patients undergoing surgery or residing in intensive care unit. The relevant question is whether SstO2 monitoring can improve the quality of care. In this article, we reviewed the clinical application of SstO2 monitoring in acute care, focusing on its use in patients undergoing surgery. Multiple small cohort studies conducted on pediatric patients reported close associations of SstO2 measurements over different regions such as the splanchnic and renal tissue beds with systemic oxygenation, transfusion, hemodynamic indices, morbidity, and mortality. Conversely, there is paucity of literature on SstO2 monitoring in adult patients. The limited number of reports suggests that SstO2 levels over bulk muscles such as the thenar eminence, forearm, and lower leg during surgery are correlated with postoperative outcomes including postoperative nausea and vomiting and the length of hospital stay in adult patients undergoing surgery. The only pilot, randomized interventional study based on 50 patients undergoing surgery did not find a difference in outcomes on the basis of the use of SstO2 monitoring. Somatic tissue oxygenation may represent an essential aspect of human physiology in acute care, and it is likely outcome-relevant based on observational cohort studies. Future research should examine whether SstO2-guided care can further improve patient outcomes using randomized controlled trials.

Near-infrared spectroscopy monitoring during out-of-hospital cardiac arrest: can the initial cerebral tissue oxygenation index predict ROSC?

Study objectivesNear-infrared spectroscopy is a modality that can monitor tissue oxygenation index (TOI) and has potential to evaluate return of spontaneous circulation (ROSC) during cardiopulmonary resuscitation (CPR). This study’s objectives...

Cerebral oxygenation in preterm infants receiving transfusion.

The influence of severity of anemia and cardiac output (CO) on cerebral oxygenation (CrSO2) and on the change in CrSO2 following packed red blood cell (PRBC) transfusion in preterm infants has not been evaluated. The objectives of the current study were to evaluate the effect of pre-transfusion hemoglobin (Hb) and CO-weighted oxygen delivery index (ODI) on CrSO2 and on the post-transfusion CrSO2 change. Preterm infants of <32 weeks gestational age (GA) receiving PRBC transfusion were enrolled. Infants received 15 ml/kg PRBC over 3 h. CrSO2 by near-infrared spectroscopy and CO by electrical velocimetry were recorded for 1 h pre-ransfusion and post transfusion. ODI was defined as pre-transfusion Hb × CO. Thirty infants of 26.6 ± 2.0 weeks GA were studied at 19 ± 12 days. Pre-transfusion Hb was 9.8 ± 0.6 g/dl. Pre-transfusion CrSO2 correlated with pre-transfusion ODI (R2 = 0.1528, p = .044) but not with Hb level. The pre-transfusion to post-transfusion CrSO2 change correlated with pre-transfusion ODI (R2 = 0.1764, p = .029) but not with Hb level. CrSO2 increased from 66 ± 6% to 72 ± 7% post transfusion (p < .001), while arterial oxygen saturation, heart rate, and CO did not change. In these infants, the pre-transfusion ODI was a better indicator of brain oxygenation and its improvement post transfusion than Hb alone. The role of CO and tissue oxygenation monitoring in assessing the need for transfusion should be evaluated.

Correlation between cerebral co-oximetry (rSO2) and outcomes in traumatic brain injury cases: A prospective, observational study

BackgroundTraumatic brain injury (TBI) is known to be an important reason for the increase in disabilities and deaths worldwide. Studies have demonstrated that brain tissue oxygen (PO2) monitoring reduces mortality significantly but is a invasive method of monitoring. Therefore, there is a need to monitor cerebral ischemia in TBI by noninvasive methods. The study aims to correlate cerebral co-oximetry and possible outcomes in patients with TBI. MethodsThe study included 78 patients with TBI admitted in intensive care unit (ICU) with glascow coma scale (GCS) of 8 or less than 8. Near-infrared spectroscopy monitor is applied to the patients immediately after admission to ICU; readings are noted every 4 hours up to first 48 hours, and outcomes studied as survival or neurological deficit are noted at 28 days. ResultsA total of 12 (15.4%) deaths were seen in this study. Survived patients were further divided into good recovery 33 (42.3%), moderate disability 21(26.9%), major disability 8 (10.3%), and persistent vegetative state 4 (5.1%). The rSO2 values in surviving patients were ranging from mean of 60.74% (standard deviation [SD] 4.38) to a mean of 64.98% (SD 5.01), and the mean rSO2 values in patients who died were ranging from a mean of 52.17% (SD 4.11) to a mean of 37.17% (SD 12.48). Lower rSO2 values were correlating significantly with worse neurological outcome or death by using two independent sample t-test (p < 0.001). ConclusionCerebral co-oximetry is a simple noninvasive method for predicting the outcomes in TBI and can be used to guide the management of these patients.