The impact of implementation of a hysterectomy enhanced recovery pathway on anesthetic medication costs.

Aim: To evaluate the effect of implementation of a hysterectomy Enhanced Recovery After Surgery (ERAS) protocol on perioperative anesthetic medication costs. Patients & methods: Historical cohort study of 84 adult patients who underwent a hysterectomy. Forty-two patients who underwent surgery before protocol implementation comprised the pre-ERAS group. Forty-two patients who underwent surgery after protocol implementation comprised the post-ERAS group. Data on anesthetic medication costs and outcomes were analyzed. Results: Compared with the pre-ERAS group, the post-ERAS group's total medication cost was significantly lower (median: 325.20 USD; interquartile range [IQR]: 256.12-430.65 USD vs median: 273.10 USD; IQR: 220.63-370.59 USD, median difference: -40.76, 95% CI: -130.39, 16.99, p = 0.047). Length of stay was significantly longer in pre-ERAS when compared with post-ERAS groups (median: 5.0 days; IQR: 4.0-7.0 days vs median: 3.0 days; IQR: 3.0-4.0 days, median difference: -2.0 days, 95% CI: -2.5581, -1.4419, p < 0.0001). Conclusion: ERAS protocols may reduce perioperative medication costs.

Development of a compact terahertz time-domain spectrometer for the measurement of the optical properties of biological tissues.

Terahertz spectrometers and imaging systems are currently being evaluated as biomedical tools for skin burn assessment. These systems show promise, but due to their size and weight, they have restricted portability, and are impractical for military and battlefield settings where space is limited. In this study, we developed and tested the performance of a compact, light, and portable THz time-domain spectroscopy (THz-TDS) device. Optical properties were collected with this system from 0.1 to 1.6 THz for water, ethanol, and several ex vivo porcine tissues (muscle, adipose, skin). For all samples tested, we found that the index of refraction (n) decreases with frequency, while the absorption coefficient (µ(a)) increases with frequency. Muscle, adipose, and frozen/thawed skin samples exhibited comparable n values ranging between 2.5 and 2.0, whereas the n values for freshly harvested skin were roughly 40% lower. Additionally, we found that the freshly harvested samples exhibited higher µ(a) values than the frozen/thawed skin samples. Overall, for all liquids and tissues tested, we found that our system measured optical property values that were consistent with those reported in the literature. These results suggest that our compact THz spectrometer performed comparable to its larger counterparts, and therefore may be a useful and practical tool for skin health assessment.

In vitro investigation of the biological effects associated with human dermal fibroblasts exposed to 2.52 THz radiation.

BACKGROUND: Terahertz (THz) radiation sources are increasingly being used in military, defense, and medical applications. However, the biological effects associated with this type of radiation are not well characterized. In this study, we evaluated the cellular and molecular response of human dermal fibroblasts exposed to THz radiation. METHODS: In vitro exposures were performed in a temperature-controlled chamber using a molecular gas THz laser (2.52 THz, 84.8 mW cm(-2), durations: 5, 10, 20, 40, or 80 minutes). Both computational and empirical dosimetric techniques were conducted using finite-difference time-domain (FDTD) modeling approaches, infrared cameras, and thermocouples. Cellular viability was assessed using conventional MTT assays. In addition, the transcriptional activation of protein and DNA sensing genes were evaluated using qPCR. Comparable analyses were also conducted for hyperthermic and genotoxic positive controls. RESULTS: We found that cellular temperatures increased by 3°C during all THz exposures. We also found that for each exposure duration tested, the THz and hyperthermic exposure groups exhibited equivalent levels of cell survival (≥90%) and heat shock protein expression (∼3.5-fold increases). In addition, the expression of DNA sensing and repair genes was unchanged in both groups; however, appreciable increases were observed in the genotoxic controls. CONCLUSIONS: Human dermal fibroblasts exhibit comparable cellular and molecular effects when exposed to THz radiation and hyperthermic stress. These findings suggest that radiation at 2.52 THz generates primarily thermal effects in mammalian cells. Therefore, we conclude that THz-induced bioeffects may be accurately predicted with conventional thermal damage models.