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

STUDY OBJECTIVES: Near-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 were to evaluate whether TOI could be associated with ROSC and used to help guide the decision to either terminate CPR or proceed to extracorporeal CPR (ECPR). METHODS: In this observational study, we assessed the patients with out-of-hospital cardiac arrest with non-traumatic cause receiving CPR on arrival at our ED between 2013 and 2016. TOI monitoring was discontinued either on CPR termination after ROSC was reached or on patient death. Patients were classified into two groups: ROSC and non-ROSC group. RESULTS: Out of 141 patients, 24 were excluded and the remaining 117 were classified as follows: ROSC group (n=44) and non-ROSC group (n=73). ROSC group was significantly younger and more likely to have their event witnessed and bystander CPR. ROSC group showed a higher initial TOI than non-ROSC group (60.5%±17.0% vs 37.9%±13.7%: p<0.01). Area under the curve analysis was more accurate with the initial TOI than without it for predicting ROSC (0.88, 95% CI 0.82 to 0.95 vs 0.79, 95% CI 0.70 to 0.87: p<0.01). TOI cut-off value ≥59% appeared to favour survival to hospital discharge whereas TOI ≤24% was associated with non-ROSC. CONCLUSIONS: This study demonstrated an association between higher initial TOI and ROSC. Initial TOI could increase the accuracy of ROSC prognosis and may be a clinical factor in the decision to terminate CPR and select patients who are to proceed to ECPR.

Light irradiation for treatment of acute carbon monoxide poisoning: an experimental study.

BACKGROUND: Because treatment modalities for carbon monoxide (CO) poisoning, especially normobaric oxygen and hyperbaric oxygen therapies, have limited effects and hyperbaric oxygen is not available at the scene where treatment is most needed, we conducted a study to determine and compare rates of carboxyhemoglobin (COHb) dissociation achieved in human in vitro blood samples under light radiation emitted at three levels of illuminance. This was done with a view toward eventual on-site application. METHODS: We drew blood from 10 volunteers, prepared 10 red blood cell solutions, and subjected each solution to a CO bubbling procedure to increase the COHb saturation. Samples of each bubbled solution were then divided between 3 beakers (beakers A, B, and C) for a total of 30 beakers. The solution in each beaker was exposed to a continuous flow of oxygen at 50 mL/min, and simultaneously for a period of 15 min, the beaker A and B solutions were irradiated with light emitted at 500,000 and 100,000 lux, respectively, from a halogen light source. The beaker C solutions were exposed to room light. At 3, 6, 9, 12, and 15 min, a 50-µL sample was pipetted from each of the 30 beakers for determination of its light absorbance and the COHb dissociation rate. RESULTS: Under each of the experimental conditions, dissociation progressed but at different rates, and starting at 3 min, the differences in rates between conditions were significant (P < 0.01). The dissociation rate was greatest with light emitted at 500,000 lux. CONCLUSIONS: Our results point toward the possibility of readily performed, acute photodissociation therapy for patients with CO poisoning.

Preliminary findings of arterial embolization with balloon-occluded and flow-dependent histoacryl glue embolization in a swine model.

PURPOSE: To evaluate the potential usefulness of the balloon-occluded histoacryl glue embolization (B-glue) technique. MATERIALS AND METHODS: Both flow-dependent (no balloon occlusion) and B-glue techniques were used for 24 intercostal arteries of two female swine. N-butyl 2-cyanoacrylate (NBCA) was diluted with lipiodol to a 50 % solution, which was infused after occluding the arteries with microballoon catheters. The embolization range, fragmentation, reflux, adhesion, and glue particle attachment were compared between flow-dependent and B-glue techniques. RESULTS: The B-glue technique was performed in a controlled fashion resulting in successful arterial occlusion without fragmented migration of the injected glue cast. Reflux occurred less frequently with the B-glue technique and was significantly different (p = 0.039) [Corrected] from that for the flow-dependent technique. Catheters were safely removed from the arterial walls, although in one instance (8.3 %), large glue particles were found to be attached to the catheter tip on removal. Conversely, the flow-dependent technique was more difficult to control and resulted in several instances of higher rates of fragmentation. CONCLUSION: The B-glue technique can efficiently control NBCA delivery with lower rates of reflux.

A new method to detect cerebral blood flow waveform in synchrony with chest compression by near-infrared spectroscopy during CPR.

OBJECTIVE: The objective of the study is to demonstrate the utility of near-infrared spectroscopy (NIRS) in evaluating chest compression (CC) quality in cardiac arrest (CA) patients as well as determine its prognosis predictive value. METHODS: We present a nonconsecutive case series of adult patients with CA whose cardiopulmonary resuscitation (CPR) was monitored with NIRS and collected the total hemoglobin concentration change (ΔcHb), the tissue oxygen index (TOI), and the ΔTOI to assess CC quality in a noninvasive fashion. RESULTS: During CPR, ΔcHb displayed waveforms monitor, which we regarded as a surrogate for CC quality. Total hemoglobin concentration change waveforms responded accurately to variations or cessations of CCs. In addition, a TOI greater than 40% measured upon admission appears to be significant in predicting patient's outcome. Of 15 patients, 6 had a TOI greater than 40% measured upon admission, and 67% of the latter were in return of spontaneous circulation after CPR and were found to be significantly different between return of spontaneous circulation and death (P = .047; P < .05). CONCLUSION: Near-infrared spectroscopy reliably assesses the quality of CCs in patients with CA demonstrated by synchronous waveforms during CPR and possible prognostic predictive value, although further investigation is warranted.

Accuracy of routine fat-suppressed FLAIR and diffusion-weighted images in detecting clinically evident acute optic neuritis.

BACKGROUND: Contrast-enhanced, fat-suppressed T1-weighted imaging (CET1WI) magnetic resonance imaging (MRI) is quite sensitive in detecting acute optic neuritis (ON), but ON remains a clinical diagnosis. MRI is indicated to evaluate demyelinating brain lesions rather than the optic nerves, while "routine" brain protocols typically include axial FLAIR and DWI. PURPOSE: To evaluate the accuracy of axial, fat-suppressed FLAIR and DWI sequences used for our routine brain imaging in detecting acute ON, as compared to CET1WI and the clinical diagnosis. MATERIAL AND METHODS: The clinical data and MRI examinations were retrospectively reviewed of 60 patients presenting to a neuro-ophthalmologist for various visual symptoms. Each patient underwent dedicated neuro-ophthalmologic examination, with axial 5 mm fat-suppressed FLAIR and DWI (part of "routine" brain MRI protocol), as well as 3 mm axial and coronal fat-suppressed CET1WI (part of dedicated orbit MRI protocol). Two neuroradiologists independently evaluated FLAIR and DWI, while CET1WI was reviewed by consensus. RESULTS: Thirty-one patients were clinically positive, 29 negative for ON (total = 34 positive and 86 negative nerves). The sensitivities of FLAIR, DWI, and CET1WI for ON were 75.7-77.3%, 77.3%, and 89.5%, respectively; the specificities were 90.5-93.5%, 80.4-82.7%, and 86.0%, respectively; the accuracies were 85.7-88.2%, 79.5-81.1%, and 87.0%, respectively. Inter-observer kappa was 0.783 for FLAIR, and 0.605 for DWI; intra-observer kappa was 0.746-0.816 for FLAIR, and 0.674-0.699 for DWI (each P < 0.0001). CONCLUSION: Being more specific, but not as sensitive, as dedicated CET1WI in acute ON, axial fat-suppressed FLAIR likely has additional value in evaluating for acute ON in "routine" brain MR protocols evaluating for demyelinating disease, while DWI may be hampered by artifacts.

Anterior ciliary sclerotomy using collagen T-shaped implants for treatment of presbyopia.

We assessed the long-term clinical outcomes and evaluate the safety, efficacy and stability of anterior ciliary sclerotomy with collagen T-shaped implants in 19 patients. The study revealed that anterior ciliary sclerotomy with collagen T-shaped implants for the treatment of presbyopia is a safe procedure, but the effect is temporary and diminishes with time.