Transcutaneous oximetry values in chronic ulcer patients during Hyperbaric treatment at 1.4 ATA compared to 2 ATA.

Chronic wounds have a significant impact on a patient's quality of life. Different pathologies, such as poor blood supply and tissue breakdown, may lead to inadequate oxygenation of the wound. Hyperbaric oxygen (HBO2) is a widely used treatment for an increasing number of medical practices. A new so-called "hyperbaric treatment" trend has emerged. The use of low-pressure, soft-sided, or inflatable chambers represents a growing trend in hyperbaric medicine. Used in professional settings as well as directly marketed to individuals for home use, they are promoted as equivalent to clinical hyperbaric treatments provided in medical centers. However, these chambers are pressurized to 1.3 atmospheres absolute (ATA) on either air or with an oxygen concentrator, both generate oxygen partial pressures well below those used in approved hyperbaric centers for UHMS-approved indications. A total of 130 consecutive patients with chronic ulcers where tested. TcPO2 was measured near the ulcer area while the patient was breathing 100% O2 at 1.4 ATA for five and 10 minutes. The average TcPO2 at 1.4 ATA after 10 minutes of O2 breathing was 161 mmHg (1-601 mmHg, standard deviation 137.91), compared to 333 mmHg in 2 ATA (1-914±232.56), p < 0.001. Each electrode tested was also statistically significant, both after five minutes of O2 breathing and after 10 minutes. We have not found evidence supporting the claim that 1.4 ATA treatment can benefit a chronic ulcer patient. The field of HBO2 is constantly evolving. We have discovered new ways to treat previously incurable ailments. Nevertheless, it is important to note that new horizons must be examined scientifically, supported by evidence-based data. The actual effect of 1.4 ATA on many ailments is yet to be determined.

Pilot study: Utility of long-wave infrared thermography as a correlate to transcutaneous oximetry for candidates of hyperbaric oxygen therapy.

Hyperbaric oxygen (HBO2 ) has been used as an adjunctive treatment for the care of advanced non-healing diabetic foot ulcers (DFUs). A patient's in-chamber transcutaneous oximetry measurement (TCOM) is currently the most effective predictor for response to HBO2 therapy but still excludes close to one in four patients who would benefit out of treatment groups when used for patient selection. Improving selection tools and criteria could potentially help better demonstrate HBO2 therapy's efficacy for such patients. We sought to identify if long-wave infrared thermography (LWIT) measurements held any correlation with a patient's TCOM measurements and if LWIT could be used in a response prediction role for adjunctive HBO2 therapy. To investigate, 24 patients already receiving TCOM measurements were enrolled to simultaneously be imaged with LWIT. LWIT measurements were taken throughout each patient's therapeutic course whether they underwent only standard wound care or adjunctive HBO2 treatments. A significant correlation was found between in-chamber TCOM and post-HBO2 LWIT. There was also a significant difference in the post-HBO2 LWIT measurement from 1st treatment to 6 weeks or the last treatment recorded. These initial findings are important as they indicate a possible clinical use for LWIT in the selection process for patients for HBO2 therapy. Larger studies should be carried out to further articulate the clinical use of LWIT in this capacity.

Effect of Different Oxygen Delivery Methods on Transcutaneous Oxygen Pressure and Fraction of Inspired Oxygen During Noninvasive Positive Pressure Ventilation.

Objective: The aim of this study was to investigate the effects of different oxygen delivery methods during noninvasive positive-pressure ventilation (NPPV) on transcutaneous oxygen pressure (PtcO2), transcutaneous carbon dioxide pressure (PtcCO2) and fraction of inspired oxygen (FiO2) in order to find more effective oxygen delivery methods. Methods: A total of 20 healthy volunteers participated in this study, all of whom received NPPV. All volunteers received oxygen through a nasal cannula (NC) located in a mask or through a mask alone (OSTM) (oxygen flow rate was 3L/min and 5L/min), PtcO2 and PtcCO2 were measured, and the effects of the 2 methods of oxygen concentration on PtcO2 and PtcCO2 levels were evaluated during noninvasive ventilation. Then, the additional oxygen concentration was stopped, oxygen was delivered through the ventilator, and the oxygen concentration was adjusted so that the PtcO2 reached the same oxygen concentration level as noted through the NC or OSTM. This concentration of oxygen indirectly reflects FiO2 in different oxygen delivery methods. Results: When NPPV was used under the same pressure, FiO2 increased from 44.4% to 65.3% when oxygen was delivered through an NC compared with oxygen supplied by OSTM alone. PtcO2 was also significantly increased from 18.9% to 24.9%; the difference was significant (P < .05), while there was no significant change in PtcCO2 (P > .05). Conclusion: When NPPV is used, an NC can obviously improve FiO2 and PtcO2 without increasing PtcCO2. It can save oxygen and is more suitable for NPPV during an emergency and for home use.

Improvement Initiative: End-Tidal Carbon Monoxide Measurement in Newborns Receiving Phototherapy.

OBJECTIVES: To determine, as part of our Utah Newborn Nursery Bilirubin Management Program, whether end-tidal carbon monoxide concentration (ETCOc) measurements in all newborns in our nursery receiving phototherapy were associated with outcomes related to the management of hyperbilirubinemia, including time (hours after birth) when phototherapy was initiated, total duration of phototherapy during the nursery stay, repeat phototherapy treatments, and hospital readmission for phototherapy. STUDY DESIGN: We performed a planned interim analysis of a component of our program in which we measured ETCOc noninvasively using CoSense on each newborn in our nursery receiving phototherapy and recorded specific outcomes related to phototherapy management. RESULTS: Of 1856 newborns admitted to our nursery in a 6-month period in 2020, 170 (9.8%) were treated with phototherapy. An ETCOc reading was successfully obtained in 145 of 151 attempts (96%). Higher ETCOc values were associated with earlier institution of phototherapy and longer duration of phototherapy. For every 1-ppm increase in ETCOc, phototherapy was started 9 hours earlier (95% CI, 3.3-14.8; P = .002) and was administered for an additional 9.3 hours (95% CI, 4.1-14.6; P < .001). Three newborns were readmitted to the hospital for intensive phototherapy; while in the nursery, all 3 had an elevated ETCOc (2.2, 2.6, and 2.9 ppm). CONCLUSIONS: Our findings provide answers to questions raised in the 2004 American Academy of Pediatrics bilirubin guidelines. In our neonatal nursery, measuring ETCOc in all phototherapy recipients was feasible and safe, and the results were associated with multiple aspects of phototherapy management. Higher ETCOc values predicted earlier and longer phototherapy courses.

Hypercapnia in COPD Patients Undergoing Endobronchial Ultrasound under Local Anaesthesia and Analgosedation: A Prospective Controlled Study Using Continuous Transcutaneous Capnometry.

BACKGROUND: Flexible bronchoscopy (FB) in analgosedation causes alveolar hypoventilation and hypercapnia, the more so if patients suffer from COPD. Nonetheless, neither is capnometry part of standard monitoring nor is there evidence on how long patients should be monitored after sedation. OBJECTIVES: We investigated the impact of COPD on hypercapnia during FB with endobronchial ultrasound (EBUS) in sedation and how the periprocedural monitoring should be adapted. METHODS: Two cohorts of consecutive patients - with advanced and without COPD - with the indication for FB with EBUS-guided transbronchial needle aspiration in analgosedation received continuous transcutaneous capnometry (ptcCO2) before, during, and for 60 min after the sedation with midazolam and alfentanil. MAIN RESULTS: Forty-six patients with advanced COPD and 44 without COPD were included. The mean examination time was 26 ± 9 min. Patients with advanced COPD had a higher peak ptcCO2 (53.7 ± 7.1 vs. 46.8 ± 4.8 mm Hg, p < 0.001) and mean ptcCO2 (49.5 ± 6.8 vs. 44.0 ± 4.4 mm Hg, p < 0.001). Thirty-six percent of all patients reached the maximum hypercapnia after FB in the recovery room (8 ± 11 min). Patients with COPD needed more time to recover to normocapnia (22 ± 24 vs. 7 ± 11 min, p < 0.001). They needed a nasopharyngeal tube more often (28 vs. 11%, p < 0.001). All patients recovered from hypercapnia within 60 min after FB. No intermittent ventilation manoeuvres were needed. CONCLUSION: A relevant proportion of patients reached their peak-pCO2 after the end of intervention. We recommend using capnometry at least for patients with known COPD. Flexible EBUS in analgosedation can be safely performed in patients with advanced COPD. For patients with advanced COPD, a postprocedural observation time of 60 min was sufficient.

Comparing near infrared spectroscopy and transcutaneous oxygen measurement in hard-to-heal wounds: a pilot study.

OBJECTIVE: Oxygen plays an integral role in all phases of the wound healing process and tissue oxygenation is a key determinant of wound healing. A comprehensive evaluation of patients with hard-to-heal wounds must include measurement of oxygenation in and around the area of skin breakdown. The current gold standard, transcutaneous oxygen measurement (TCOM), has numerous drawbacks and as a result has fallen into disuse. METHOD: This study compared measurement of tissue oxygenation of near infrared spectroscopy (NIRS) with TCOM in patients with acute and hard-to-heal wounds. The Shapiro-Wilk test was used to evaluate the normality of the data. The level of agreement between NIRS and TCOM was determined using Bland-Altman analysis. The relationship between TCOM and NIRS was examined using Pearson correlation. RESULTS: A total of 24 observations were obtained from 10 patients using TCOM and NIRS. The weighted mean partial pressure of oxygen (pO2) in the study population was 39.54mmHg (8.96 standard deviation). Bland-Altman analysis showed that mean difference was positive (18.75), suggesting an overestimation of oxygen measurements using TCOM compared with NIRS. The oxygen levels measured by TCOM and NIRS showed a strong correlation (r=0.74). CONCLUSION: The wound and hyperbaric community would benefit from a simplified procedure for measuring tissue oxygenation. These findings suggest a strong trend toward correlation between NIRS and TCOM. A further study in a larger population is recommended. NIRS offers several advantages over TCOM. Clinicians have immediate point-of-care visualisation of tissue oxygenation using a handheld device. The procedure takes minutes to perform and is less operator-dependent than TCOM. Finally, NIRS allows measurement of oxygenation in the wound bed, while TCOM does not.

Comparison of preoxygenation with a high-flow nasal cannula and a simple mask before intubation during induction of general anesthesia in patients undergoing head and neck surgery: Study protocol clinical trial (SPIRIT Compliant).

BACKGROUND: To assess the arterial oxygen partial pressure (PaO2) at defined time points during preoxygenation and to compare high-flow heated humidified nasal oxygenation with standard preoxygenation using oxygen insufflation via a facemask for at least 5 minutes, before intubation during induction of general anesthesia. METHODS: This randomized, single-blinded, prospective study will be conducted in patients undergoing head and neck surgery. After standard monitoring, the artery catheter at the radial artery or dorsalis pedis artery will be placed and arterial blood gas analysis (ABGA) for baseline values will be performed simultaneously. Each group will be subjected to 1 of 2 preoxygenation methods (high-flow nasal cannula or simple facemask) for 5 minutes, and ABGA will be performed twice. After confirming intubation, we will start mechanical ventilation and check the vital signs and perform the final ABGA. DISCUSSION: This trial aims to examine the trajectory of PaO2 levels during the whole preoxygenation procedure and after intubation. We hypothesize that preoxygenation with the high-flow nasal cannula will be superior to that with the face mask. STUDY REGISTRATION: This trial was registered with the Clinical Trial Registry (NCT03896906; ClinicalTrials.gov).

Trends and characteristics of cases when serial carboxyhemoglobins are obtained.

BACKGROUND: Carboxyhemoglobin (COHb) levels are obtained when there is suspicion for carbon monoxide (CO) exposure. Serial COHb levels are sometimes obtained despite the well-established half-life of COHb with oxygen supplementation. We sought to evaluate the trends and characteristics associated with obtaining serial carboxyhemoglobin levels. METHODS: A retrospective review was performed at an academic medical center for all inpatient and emergency department cases with either single COHb or serial COHb levels from 1 April 2010 through 31 March 2015. Data collected included age, gender, pregnancy status, smoking history, encounter month, admission status, oxygen administration, fire or burn history, vital signs, presenting symptoms, hyperbaric oxygen (HBO2) therapy use, initial pH, troponin, lactate, and COHb levels. The time and change in values between serial levels were also obtained. RESULTS: 624 cases were identified, with 106 (17%) having multiple carboxyhemoglobin levels. A mean of 2.6 (range 2 - 9) serial COHb levels were obtained. The average initial COHb was 8.9%. Subsequent serial levels were obtained on average at 353, 663 and 1,095 minutes and averaged 2.8%, 1.8% and 1.1% respectively. Serial COHb levels were obtained more commonly in burn patients, those admitted to the ICU and those who had HBO2 therapy. Four patients had an increase in COHb level on serial testing. The largest increase of these was from 2.0% to 3.9%. CONCLUSION: Serial COHb levels were not infrequent in this study. No clinically significant increase in COHb was identified by serial testing. Further studies should examine the clinical utility of such practices.

Adjuvant therapy efficacy of Chinese drugs pharmaceutics for COPD patients with respiratory failure: a meta-analysis.

We performed a meta-analysis to evaluate the efficacy and safety of Western medicine combined with Tanreqing for patients with chronic obstructive pulmonary disease (COPD) and respiratory failure. We comprehensively searched several online databases from the times of their inception to November 2018. The trial quality was assessed using the bias risk tool recommended by the Cochrane library. Relative risks (RRs) and their 95% confidence intervals (CIs) for binary outcomes and weighted mean differences (MDs) with 95% CIs for continuous data were calculated. A fixed effect model indicated that integrated Tanreqing group experienced higher overall treatment effectiveness (RR = 1.23, 95% CI: 1.17-1.30, P=0.000). Pooled results from random effects models indicated the oxygen partial pressure of the test group was significantly higher than that of the control groups (MD = 9.55, 95% CI: 4.57-14.52, P<0.000). The carbon dioxide pressure of the test group was significantly lower than that of the control groups (MD = -6.06, 95% CI: -8.19 to -3.93, P=0.000). The lung function score of the test group was significantly higher than that of the control group (MD = 7.87, 95% CI: 4.45-11.29). Sensitivity analysis indicated that the data were statistically robust. Clinical effects of Western medicine combined with Tanreqing used to treat combined COPD/respiratory failure were better than those afforded by Western medicine; no serious adverse reactions were noted. However, publication bias was evident, and further trials with larger sample sizes are required.

Use of in-chamber transcutaneous oxygen measurement to determine optimal treatment pressure in patients undergoing hyperbaric oxygen therapy.

INTRODUCTION: Hyperbaric oxygen (HBO2) therapy is used to promote healing in select problem wounds. Transcutaneous oxygen measurement (TCOM) can be used to predict the response of these wounds to HBO2, with in-chamber TCOM values shown to be the most predictive. We evaluated the use of in-chamber TCOM values to determine optimal treatment pressure. METHODS: A retrospective review was completed of patients undergoing HBO2 therapy for a lower-extremity wound and who had in-chamber TCOM. Data collected included TCOM values, treatment profile, and patient outcome. RESULTS: A total of 142 patients were identified. The overall results demonstrated healing in 59%, minor amputation (below ankle) in 11.3%, and major amputation (above ankle) in 16.2% of patients. 79.3% of patients at 2 atmospheres absolute (ATA) and 86.6% of patients at 2.4 ATA had transcutaneous oxygen pressure (TcPO2) values ≥250 mmHg. Among those with TcPO2 ⟨250 mmHg at 2 ATA, 41% attained TcPO2 ⟩250 mmHg at 2.4 ATA. Among those treated at 2 ATA the healing rate was 70.6% if TcPO2 ⟩250 mmHg, and 11.8% if TcPO2 ⟨250 mmHg (P⟨0.001). Among those treated at 2.4 ATA the healing rate was 33.3% if TcPO2 ⟩250 mmHg and 14.3% if TcPO2 ⟨250 mmHg (P⟨0.001). DISCUSSION: Determining optimal therapeutic pressure for patients undergoing HBO2 is important to maximize benefit and minimize risk. This study indicates that in-chamber TCOM can be used to select an individualized optimal treatment pressure in patients undergoing HBO2 for lower-extremity wounds, including diabetic foot ulcers. This may result in better utilization of HBO2 and better outcomes.

Combined Hyperbaric Oxygen Partial Pressure at 1.4 Bar with Infrared Radiation: A Useful Tool To Improve Tissue Hypoxemia?

Tissue hypoxia contributes to the pathogenesis of several acute and chronic diseases. Hyperbaric oxygen therapy (HBO) and whole-body warming using low-temperature infrared technology (LIT) are techniques that might improve hypoxemia. Combining HBO and LIT as hyperbaric oxygen therapy combined with low-temperature infrared radiation (HBOIR) might be an approach that results in positive synergistic effects on oxygenation. LIT increases blood flow and could reduce HBO-induced vasoconstriction, and hyperoxia could compensate for the increased metabolic oxygen requirements mediated by LIT. Both LIT and HBO increase the oxygen diffusion distance in the tissues. HBOIR at 0.5 bar has been shown to be safe and feasible. However, physiological responses and the safety of HBOIR at an increased oxygen (O2) partial pressure of 1.4 bar or 2.4 atmospheres absolute (ATA) still need to be determined. The hope is that should HBOIR at an increased oxygen partial pressure of 1.4 bar be safe, future studies to examine its efficacy in patients with clinical conditions, which include peripheral arterial disease (PAD) or wound healing disorders, will follow. The results of pilot studies have shown that HBOIR at an overload pressure is safe and well tolerated in healthy participants but can generate moderate cardiovascular changes and an increase in body temperature. From the findings of this pilot study, due to its potential synergistic effects, HBOIR could be a promising tool for the treatment of human diseases associated with hypoxemia.

Computerized planimetry evaluation of hyperbaric oxygen therapy in the treatment of diabetic foot.

BACKGROUND: Diabetic foot ulcer is one of the major complications of diabetes mellitus in adults. OBJECTIVES: The aim of the study was to conduct a planimetry evaluation of the effectiveness of hyperbaric oxygen therapy (HBOT) in the treatment of patients with vascular disorders caused by diabetic foot. MATERIAL AND METHODS: The study included 94 patients, 30 females (32%) and 64 males (68%), aged 33-76 years, with diabetes lasting 1.5-32 years, who underwent HBOT due to diabetic foot. All patients from that group underwent vascular procedures prior to HBOT. In qualifying patients for hyperbaric oxygen therapy, transcutaneous oximetry method was applied (30-60 exposures in hyperbaric oxygen at pressure of 2.5 ATA). Progress in wound healing was evaluated by computerized planimetry system IRIS 4. RESULTS: In 26 patients the wounds were completely closed and in 37 patients the topical state was significantly improved - the wound surface decreased by 34% in average. During the treatment, in 11 patients amputation of fingers and metatarsal necrotic bones was performed, while in 9 patients amputation was prevented. CONCLUSIONS: A planimetry evaluation showed that the application of HBOT in the treatment of diabetic foot enhances foot ulcer healing, reduces tissue damage, contributes to the reduction of complications related to soft tissue and bone infections.

In Patients with Severe Peripheral Arterial Disease, Revascularization-Induced Improvement in Lower Extremity Ischemia Can Be Detected by Laser Speckle Contrast Imaging of the Fluctuation in Blood Perfusion after Local Heating.

BACKGROUND: We previously reported the utility of the perfusion value (PV) fluctuation slope for detecting severe ischemia in the lower limb. Our approach was based on a thermal load test mimicking the well-known physiological reaction termed "cold-induced vasodilation," which is known to occur as a 3-phase phenomenon. The slope parameter quantifies the decrease in PVs accompanying the relative cooling (third phase) following the transient increase in blood flow (second phase) induced by the applied thermal load. This phenomenon of "relative" cold-induced vasodilation (rCIVD) can be monitored using laser speckle contrast imaging (LSCI) after applying the thermal load (LTL test). Here, we aimed to determine whether the slope parameter obtained via the LTL test also reflects the improvement in hemodynamics after revascularization. METHODS: The study enrolled 16 patients (18 limbs), who underwent revascularization for peripheral arterial disease (PAD). The measurements were performed at 2 sites in each limb (in total, 34 sites; 2 sites in one patient were excluded because of significant movement during the measurement). For each site, we recorded the slope describing the behavior of PVs (decrease or plateau) in the third phase of rCIVD, following the initial, heating-induced increase in perfusion (second phase of rCIVD). The plateau group (group P), which included patients with an abnormal rCIVD, and the decrease group (group D), which included patients with a normal rCIVD, were defined based on perfusion slope values of <0.20 and ≥ 0.20 perfusion units/min, respectively. We also quantified the transient increase in perfusion (from baseline to peak) as a descriptor of perfusion behavior during the second phase of rCIVD. RESULTS: In group P, the change in median values (25-75%) of the slope, transcutaneous oxygen tension, and ankle-brachial index (ABI) from before to after operation was (-0.02 [-0.04 to 0.02]; 4 [1-11]; and 0.08 [0-0.27]) to (0.39 [0.32-0.59]; 46 [37-54]; and 0.81 [0.72-0.90]). Conversely, in group D, the change in the median values of the slope, transcutaneous oxygen tension, and ABI between before and after operation was (0.38 [0.32-0.49]; 40.5 [35-45]; and0.58 [0.57-0.65]) to (0.44 [0.30-0.64]; 52 [43-56]; and 0.92 [0.81-0.99]). Sites exhibiting perfusion pattern of group D in the third phase of rCIVD showed no significant change in slope after revascularization (P = 0.21), whereas the slope in group P increased significantly after revascularization, becoming similar to the postoperative slopes in group D (P = 0.81). The amount of transient increase in perfusion, which quantified the behavior in the second phase of rCIVD, showed a similar behavior. Preoperatively, all patients in group P had rest pain and/or ulcer of the foot, whereas only few patients in group D had such symptoms. CONCLUSIONS: Normal rCIVD response in the LTL test indicates less-than-severe ischemia, while abnormal rCIVD response measured via the LTL test indicates severe ischemic symptoms, such as critical limb ischemia. Notably, patients with an abnormal rCIVD response can develop a normal rCIVD response following revascularization, thereby reflecting an improvement in blood flow. The LTL test assessing rCIVD response can be useful for detecting severe limb ischemia, such as critical limb ischemia (CLI), and determining the departure from severe limb ischemia by revascularization.

A ZigBee-based wireless system for monitoring vital signs in hyperbaric chambers: Technical report.

This paper presents the replacement of a traditional wired communication link of the hyperbaric chambers with a wireless ZigBee-based system. This move allows a reduction in the costs of seals capable of withstanding the internal pressures and gives rise to a more versatile system. The new system is able to capture and process individual vital signs like the electrocardiography signal, and other analog sources, sending the data to an external computer and allowing analysis, representation and sharing with medical staff. This system solves such problems as the attenuation of the signal produced by the metal walls of the hyperbaric chamber and has a coverage area large enough to manage up to six patients with an effective data rate conversion of 2kHz. Furthermore, a battery-based and multiparameter platform is designed for multipatient hyperbaric chambers.

A Multisite Benchmarking Trial of Capnometry Guided Respiratory Intervention for Panic Disorder in Naturalistic Treatment Settings.

Panic disorder (PD) is associated with hyperventilation. The efficacy of a brief respiratory feedback program for PD has been established. The aim of the present study was to expand these results by testing a similar program with more clinically representative patients and settings. Sixty-nine adults with PD received 4 weeks of Capnometry Guided Respiratory Intervention (CGRI) using Freespira, which provides feedback of end-tidal CO2 (PETCO2) and respiration rate (RR), in four non-academic clinical settings. This intervention is delivered via home use following initial training by a clinician and provides remote monitoring of client adherence and progress by the clinician. Outcomes were assessed post-treatment and at 2- and 12-month follow-up. CGRI was associated with an intent-to-treat response rate of 83% and a remission rate of 54%, and large decreases in panic severity. Similar decreases were found in functional impairment and in global illness severity. Gains were largely sustained at follow-up. PETCO2 moved from the slightly hypocapnic range to the normocapnic range. Benchmarking analyses against a previously-published controlled trial showed very similar outcomes, despite substantial differences in sample composition and treatment settings. The present study confirms prior clinical results and lends further support to the viability of CGRI in the treatment of PD.

Are Oxygen and Related Compounds the Mechanisms Underlying Acupoint Function? A Review of Acupoint Oxygen Specificity Studies.

Oxygen specificity of acupoints has been studied for nearly 30 years. Studies have considered oxygen partial pressure, nitric oxide, carbon dioxide, and other factors. The results of the experiments have shown that the content of oxygen and oxygen-related compounds is statistically significantly different between acupoint and non-acupoint tissues. Despite certain differences in the methods and results across studies, including some contradictory experimental data, most reports agree that metabolic activity, utilization of oxygen, and activity of oxygen-related compounds were higher in acupoint tissues than in non-acupoint tissues. The characteristics of an acupoint may be based on the anatomical structure of the surrounding tissue. Modern sensor needle technology has been widely applied in the study of acupoint oxygen specificity, providing scientific and objective evidence. However, the study of acupoint oxygen specificity has not been without controversy. In order to give practical significance to this research, study design, repeatability of experimental conditions, and homogeneity of subjects should be considered more precisely. Also, more attention should be paid to clinical relevance, i.e., by inclusion of clinical cases and observation of the de-qi effect and clinical responses in the future.

Assessing the effects of a short-term green tea intervention in skin microvascular function and oxygen tension in older and younger adults.

Green tea consumption has been associated with a reduction in cardiovascular disease risk factors. However, there is little evidence examining its potential differing effect between younger and older populations, whilst little is known on its effect on the circulatory system when oxygen demand is higher. Therefore the aim of this study was to evaluate the short-term effects of green tea consumption on microvascular functioning in both an older and younger population. Fifteen young [24 (4.0)] and fifteen older [61 (4.0)] participants, consumed two cups of green tea daily for 14days. We used Laser Doppler Flowmetry (LDF) to assess cutaneous microvascular function and Transcutaneous Oxygen monitoring (TcPO2) to assess skin oxygen tension. Systolic and diastolic blood pressure were also assessed on both visits. We observed significant improvements in axon-mediated microvascular vasodilation for the younger group [1.6 (0.59) vs 2.05 (0.72), p<0.05] and the older group [1.25 (0.58) vs 1.65 (0.5) p<0.05]. Improvements in skin oxygen tension were also noted for both groups in both noted TcPO2 measures (i.e. 1.25 (0.58) vs 1.65 (0.5) (p<0.05), for ΔTcPO2max for the older group, between visits) respectively. Improvements were also observed for systolic blood pressure in both the younger [120 (10) vs 112 (10), p<0.05] and older group [129 (12) v 124 (11), p<0.001]. In conclusion, we observed statistically-significant improvements in microvascular function and skin oxygen tension. Our results suggest that green tea may prove beneficial as a dietary element in lifestyle interventions aiming to lower cardiovascular disease risk, in both older and younger populations.

The validity of transcutaneous oxygen measurements in predicting healing of diabetic foot ulcers.

INTRODUCTION: In 2002 Fife and Strauss (Fife, et al. Wound Rep Reg, 10:198-207; Strauss, et al. Foot Ankle Intl, 23:933-937) studied the predictability of transcutaneous oxygen measurements (TCOMs) for healing diabetic foot ulcers (DFUs). This paper analyzes the validity of the two studies and combines their information to predict which DFU will heal with adjunctive hyperbaric oxygen (HBO2) treatments. METHODS: A statistical review of the Fife and Strauss papers was performed. The numbers presented in the papers were subjected to analyses to compare like by like data as well as test for p-values and odds ratios for predicting healing of DFUs with HBO2. RESULTS: In the Strauss paper 143 subjects were studied in retrospective and prospective series. In those TCOMs which exceed 200 mmHg with HBO2 healing occurred in 87.5% even if the room air TCOM was ⟨ 30 mmHg (p ⟨ 0.001). The Fife paper studied retrospectively a subset of 221 patients who had TCOMs with HBO2. Failure rates for healing decreased progressively from 35.7% to 14.3%, with TCOMs grouped in 100-mmHg increments from 200 mmHg to 699 mmHg. This resulted in absence of statistical significance for any 100-mmHg range over 200 mmHg with HBO2 due to the small number of subjects for each 100-mmHg grouping. CONCLUSIONS: Although differences exist between the study designs, each complements the other. If TCOMs exceed 200 mmHg with HBO2, both authors observed that almost 90% of DFUs healed regardless of the room air readings when HBO2 was used as an adjunct to management.

Extra-cerebral oxygenation influence on near-infrared-spectroscopy-determined frontal lobe oxygenation in healthy volunteers: a comparison between INVOS-4100 and NIRO-200NX.

INTRODUCTION: Frontal lobe oxygenation (Sc O2 ) is assessed by spatially resolved near-infrared spectroscopy (SR-NIRS) although it seems influenced by extra-cerebral oxygenation. We aimed to quantify the impact of extra-cerebral oxygenation on two SR-NIRS derived Sc O2 . METHODS: Multiple regression analysis estimated the influence of extra-cerebral oxygenation as exemplified by skin oxygenation (Sskin O2 ) on Sc O2 in 21 healthy subjects exposed to whole-body exercise in hypoxia (Fi O2  = 12%; n = 10) and normoxia (n = 12), whole-body heating, hyperventilation (n = 21), administration of norepinephrine with and without petCO2 -correction (n = 15), phenylephrine and head-up tilt (n = 7). Sc O2 was assessed simultaneously by NIRO-200NX (Sniro O2 ) and INVOS-4100 (Sinvos O2 ). Arterial (Sa O2 ) and jugular bulb oxygen saturations (Sj O2 ) were obtained. RESULTS: The regression analysis indicated that Sinvos O2 reflects 46% arterial, 14% jugular, 35% skin and 4% oxygenation of tissues not interrogated. Sinvos O2 follows a calculated estimate of cerebral capillary oxygenation (r = 0·67; P<0·0001). In contrast, the NIRO-200NX-determined Sc O2 did not correlate with the estimate of cerebral oxygenation (r = 0·026; P = 0·71). CONCLUSION: For all interventions, 35% of the INVOS-4100 signal reflected extra-cerebral oxygenation while, on the other hand, NIRO-200NX did not follow changes in a calculated estimate of cerebral capillary oxygenation. Thus, the NIRO-200NX and INVOS-4100 do not provide for unbiased evaluation of the cerebral signal.

Evaluation of TCOM/HBOT practice guideline for the treatment of foot burns occurring in diabetic patients.

OBJECTIVES: A multidisciplinary team developed an evidence-based guideline for the management of foot burns occurring in diabetic patients that included transcutaneous oxygen measurements (TCOM) and application of hyperbaric oxygen therapy (HBOT) to selected patients. This report represents an evaluation of preliminary TCOM/HBOT data. METHODS: This is a retrospective review of patients with diabetes mellitus (DM) who were admitted to a single American Burn Association (ABA) verified burn center for the treatment of foot burns. Patients were treated via the guideline if they were over the age of 16, admitted for the initial care of burns involving the feet between 4/01/2012 and 7/22/2013, and had a known or new diagnosis of DM. RESULTS: Eighteen patients were treated according to the guideline, 14 men and 4 women. Average age was 54 years+14.78. Average BMI was 30.63+6.34. Median burn size was 0.88% TBSA (median partial thickness of 1% and median full thickness of 0.5%). The average HbA1c was 9.08+2.42. Seven patients received pre-operative HBOT, two received post-operative HBOT and three patients healed their wounds with HBOT alone. Average hospital length of stay was 13.39 days+9.94 and was significantly longer for the group receiving HBOT. Admission HbA1c was not a predictor of the need for HBOT. CONCLUSIONS: While TCOM/HBOT therapy has not been widely applied to the management of diabetic foot burns, the use of an evidence-based guideline incorporating TCOM/HBOT can provide a systematic way to evaluate the patients' microcirculation and ability to heal burns of the foot. The incorporation of TCOM determination and application of HBOT in selected patients with DM and burns of the feet warrant continued study.