Measurement of Tissue Oximetry in Standing Unsedated and Sedated Horses

Near infrared spectroscopy (NIRS) noninvasively measures peripheral tissue oxygen saturation (StO2) and may be useful to detect early changes in StO2 in anaesthetized and critically ill horses. This study aimed to identify the muscle belly that provided the highest percentage of successful StO2 readings and the highest mean StO2 value. Fifty adult horses were enrolled in a prospective controlled study. StO2 was measured at six different muscles in each horse, for each intervention: hair overlying the muscle was clipped (post clipping: PC), clipped skin was cleaned with chlorhexidine (post-surgical prepping: PP) and medetomidine was administered intravenously (post medetomidine: PM). Mean StO2 values were calculated for each muscle, and a linear effects model was used to assess the effect of muscle group and intervention on StO2. The sartorius muscle gave the highest percentage of successful StO2 values (p < 0.001) and the highest mean (90% CI) StO2 values for the PC, PP and PM interventions. Surgical prepping of the skin increased the success for measurement of StO2 values. For all muscles, administration of medetomidine was associated with lower StO2 values (p < 0.001). In conclusion, of the muscles examined, the sartorius muscle may be the preferred muscle to measure StO2 in horses, and clipping and cleaning of the probe placement site is recommended.

1362 Early Experience on Flap Perfusion? Monitoring with Near-Infrared Spectroscopy Tissue Oximetry

Introduction Free flap reconstruction is a routine procedure with more than 99% success rates. Yet, vascular complications may occur leading to flap failure. Thus, early detection of vascular compromise is crucial for flap salvage. Vascular complications may be detected early using Infrared Spectroscopy Tissue Oximetry (NIRS) parameter changes. This method can distinguish changes caused by arterial and venous thrombosis before surgical re-exploration. This study aims to assess the validity or feasibility of using NIRS Oximetry in free flap monitoring and compare it to standard clinical examination and Doppler . Method A prospective cohort observational study. Flap perfusion was measured using the INVOS™ 7100 system for 24-h continuous postoperative monitoring. The data were compared to findings of clinical assessment. Results Ten patients completed the measurements after breast flap reconstruction. Age ranged from 41 to 61 years. Patients underwent immediate d eep inferior epigastric perforators (DIEP) (n = 4), delayed DIEP (n = 4), transverse upper gracilis flap (n = 1), and latissimus dorsi flap with lipofilling (n = 1). All ten flaps are successfully monitored for 24hrs post-operatively. The overall flap survival was 100%. Clinical examination, Doppler studies and surgical outcome were consistent with NIRS (need numbers). There were no false negatives. Conclusions NIRS tissue oximetry could potentially monitor flaps non-invasively. Future adequately sampled cohort study is recommended.

Exploring personalized postoperative non-invasive tissue oximetry in DIEP flap breast reconstruction

Early detection of vascular compromise after autologous breast reconstruction is crucial to enable timely re-exploration for flap salvage. Several studies proposed non-invasive tissue oximetry for early identification of ischemia of deep inferior epigastric perforator (DIEP) flaps. The present study aimed to explore the utility of non-invasive tissue oximetry following DIEP flap surgery using a personalized oxygenation threshold. Methods Patients undergoing immediate/delayed DIEP flap surgery were included in this prospective observational study. DIEP flap tissue oxygenation (StO2) was monitored continuously using near-infrared spectroscopy. A baseline measurement was performed by positioning one sensor at the marked position of the major inferior epigastric perforator on the abdomen. A new sensor was positioned postoperatively on the transplanted tissue. In unilateral procedures, postoperative StO2 values of the native breast were also obtained. Measurements were continued for 24 h. Results Thirty patients (42 flaps) were included. Fourteen patients (46.7%) had an uncomplicated postoperative course. A minor complication was observed in thirteen patients; in five patients, at least one major complication occurred, requiring re-exploration. Median StO2 readings were significantly lower in patients with major complications compared to uncomplicated cases. In fourteen unilateral DIEP flap procedures, StO2 values of the native breast were similar to the preoperative baseline measurement (92%; p = 0.452). Conclusions Non-invasive tissue oximetry following DIEP flap surgery could aid in early detection of vascular compromise. StO2 values of the native breast and abdominal wall preoperatively can be used interchangeably and can serve as personalized reference value. Level of evidence: Level IV, diagnostic / prognostic study.

Treatment of anaerobic phlegmon of the upper extremity induced by Clostridium perfringens via application of an oxygenated pharmaceutical

At the present time, cases of gas infection are extremely rarely encountered. The incidence of anaerobic gas infection totals 0.1-1.0 cases in 1,000,000 of the population per year. The clinical case presented describes peculiarities in clinical progression of the disease, of its surgical and complex treatment. The dynamics of multiple organ dysfunction markers has been shown. On admission, the predicted lethal outcome rate totalled 66.7% to 82%. The treatment included local and peroral application of an oxygenated pharmaceutical. Tissue oximetry revealed elevation of blood oxygen saturation 30 and 60 minutes after the oxygenated pharmaceutical intake. The surgical tactics employed and the pathogenetic therapy combined with local and peroral application of the oxygenated pharmaceutical made it possible to achieve a positive treatment outcome

The False Positive Rate of Transcutaneous Tissue Oximetry Alarms in Microvascular Breast Reconstruction Rises after 24 Hours

Background Transcutaneous tissue oximetry is widely used as an adjunct for postoperative monitoring after microvascular breast reconstruction. Despite a high sensitivity at detecting vascular issues, alarms from probe malfunctions/errors can generate unnecessary nursing calls, concerns, and evaluations. The purpose of this study is to analyze the false positive rate of transcutaneous tissue oximetry monitoring over the postoperative period and assess changes in its utility over time. Patients and Methods Consecutive patients undergoing microvascular breast reconstruction at our institution with monitoring using transcutaneous tissue oximetry were assessed between 2017 and 2019. Variables of interest were transcutaneous tissue oximetry alarms, flap loss, re-exploration, and salvage rates. Results The study included 175 patients (286 flaps). The flap loss rate was 1.0% (3/286). Twelve patients (6.8%) required re-exploration, with 9 patients found to have actual flap compromise (all within 24 hours). The salvage rate was 67.0%. The 3 takebacks after 24 hours were for bleeding concerns rather than anastomotic problems. Within the initial 24-hour postoperative period, 43 tissue oximetry alarms triggered nursing calls; 7 alarms (16.2%) were confirmed to be for flap issues secondary to vascular compromise. After 24 hours, none of the 44 alarms were associated with flap compromise. The false positive rate within 24 hours was 83.7% (36/43) compared with 100% (44/44) after 24 hours (p = 0.01). Conclusion The transcutaneous tissue oximetry false positive rate significantly rises after 24 hours. The benefit may not outweigh the concerns, labor, and effort that results from alarms after postoperative day 1. We recommend considering discontinuing this monitoring after 24 hours.