Day of surgery: the impact on patient length of stay in a tertiary vascular unit.

BACKGROUND: Our hypothesis was that patients undergoing surgery earlier in the week would have better access to physiotherapy and other discharge services after surgery and, as a result, would have a shorter length of hospital stay compared with patients undergoing surgery later in the week. This study aimed to assess whether there is a significant difference in postoperative length of hospital stay between the groups with secondary assessment by operation subtype. METHODS: We identified all patients admitted for vascular surgery in 2015 from a prospectively collected database and divided the week into Monday to Wednesday and Thursday to Friday. Endovascular cases were included but day cases were excluded. Further analysis was performed with a breakdown in both groups by operation type. Statistical analysis was performed using SPSS version 16.0. RESULTS: We identified 652 patients who met our criteria. Within the elective patient group, there was a significantly longer length of stay of three days for the late-week group compared with two days for the early-week group (P = 0.016). Femoral artery procedures had a median length of stay of two days for those operated on early in the week compared with four days later in the week (P < 0.005). Open abdominal aortic aneurysm repair showed a trend to longer length of stay in the late-week group (P = 0.06). CONCLUSION: Day of surgery appears to impact on patients' length of stay following vascular procedures, with the greatest impact on medium-sized procedures. This difference could be explained by the difference in weekend support services, but further evaluation is required following introduction of weekend support services to assess this.

Stability of beta-actin mRNA in plasma.

It has long been thought that mRNA is labile and easily prone to degradation. However, a recent study demonstrated that GAPDH mRNA in cell-free plasma may remain stable up to 24 hours after blood collection. As there are no other independent studies, we attempted to reproduce the findings of that study. In our study, blood was collected from a healthy male volunteer into Vacutainer tubes containing EDTA. Blood samples were placed on ice and plasma separated by double-centrifugation at times 0, 1, 2, and 5 hours after blood collection. mRNA was extracted from four aliquots of the blood sample by means of the QIAamp Viral RNA kit. Extracted mRNA was converted to cDNA by reverse transcription before real time quantitative PCR measurement of the housekeeping beta-actin gene. Plasma beta-actin mRNA at 2 hours (0.012; 0.0031-0.0297, median and range) was significantly lower (P= 0.022) than at 0 hours (0.12; 0.057-0.165) (P= 0.016). The levels decreased further at 5 hours (0.0037; 0.0024-0.011) (P= 0.004). The results show that plasma beta-actin mRNA levels decrease with time after blood collection and that this is likely to be due to degradation in vitro.

Normalization of circulating nucleic acid results.

Nucleic acids, both DNA and mRNA, have been detected in the circulation and have been demonstrated to be useful in such areas as fetal medicine, oncology, and transplantation. When mRNA is measured in circulating blood, the results are expressed in relation to a reference gene product in order to correct for any differences in extraction, volume of starting material or other differences. Many authors use beta-actin mRNA and express results as a ratio of target mRNA to beta-actin mRNA. We have used a similar approach when studying diabetic retinopathy. Recently, we planned to investigate the expression of thyroid dependent gene expression in acutely ill patients. As a control study, we examined the expression of thyroid hormone-dependent gene expression in subjects with hyperthyroidism and found that the expression of beta-actin mRNA was affected by thyroid hormone status. Blood samples were taken into PAX genetrade mark tubes from 31 healthy subjects (mean age, 43 +/- 16 yrs) and 7 patients with hyperthyroidism (mean age, 43 +/- 5 yrs). Diagnosis of hyperthyroidism was confirmed by clinical findings and biochemical results. After extraction of mRNA, cDNA was synthesized using reverse transcription. Quantification of Na/K-ATPase, T3 receptor, and beta-actin cDNA was carried out by RT-PCR. Median beta-actin levels were significantly higher in hyperthyroid subjects compared to healthy subjects (18.2 versus 2.30; P < 0.00042). When mRNA for the T3 receptor was expressed in relation to beta-actin, there was a significantly higher in hyperthyroidism (0.0168 versus 0.218, P < 0.05). However, this was significantly lower when expressed in relation to total RNA (12.2 versus 2.24, P < 0.00015). We conclude that normalizing results to beta-actin may not be appropriate in all circumstances.