Correlation of ultrasound measurement of limb muscle thickness and echo intensity with frailty assessment in elderly patients undergoing malignancies surgery.

Introduction: It remains controversial which frailty score correlates with adverse outcomes. Instead of these subjective and time consuming scores, we studied whether ultrasound guided lower extremity thickness measurements more closely are associated with adverse outcomes. Method: Patients undergoing gastrointestinal malignancy surgery were included as study subjects. Frailty was identified using the FRAIL scale assessment. Ultrasound measured the muscle thickness and echo intensity of the patient's upper and lower limbs. ANOVA was used to analyze the relationship between muscle data and frailty assessment. Significant indicators from the one-way analysis were included in the multivariate logistic regression equation. Results: A total of 160 study subjects were included, 52 in the normal group, 78 in the prefrailty group, and 30 in the frailty group. The ANOVA showed that there were significant differences in age, hemoglobin, albumin, history of hypertension, history of coronary artery disease, the history of cerebrovascular disease, rate of postoperative complications, rate of transferring to intensive care unit, time out of bed, length of hospitalization, thickness and echo intensity of quadriceps femoris the vastus lateralis and the tibialis anterior, echo intensity of the medial gastrocnemius among the three groups (P < 0.05). Pearson's correlation analysis showed FRAIL score was correlated with muscle thickness and echo intensity of the lower limbs. Multifactor logistic regression analysis showed that the prefrailty group was positively correlated with age（ߠ= 0.146, P = 0.004）, echo intensity of the medial gastrocnemius (ß = 0.055, P = 0.031), and rate of postoperative complications（ߠ= 1.439, P = 0.021）, also negatively correlated with muscle thickness of the tibialis anterior（ߠ= -2.124, P = 0.007）. The frailty group was positively correlated with age（ߠ= 0.22, P = 0.005）, tibialis anterior echo intensity (ß = 0.082, P = 0.015), medial gastrocnemius echo intensity (ß = 0.089, P = 0.026), cerebrovascular disease history (ß = 2.311, P = 0.04), and postoperative complication rate (ß = 2.684, P = 0.003). It was negatively correlated with albumin (ß = -0.26, P = 0.017), quadriceps muscle thickness (ß = -2.257, P = 0.017), and tibialis anterior muscle thickness (ß = -5.408, P = 0.001). Conclusion: Ultrasound measurement of lower (not upper) extremity muscle thickness and echo intensity was significantly associated with discriminating severity of frailty and postoperative outcomes than frailty scores in elderly patients.

Dexmedetomidine combined with ropivacaine in ultrasound-guided tranversus abdominis plane block improves postoperative analgesia and recovery following laparoscopic colectomy.

The present prospective, double blind, randomized clinical study was designed to evaluate whether dexmedetomidine (Dex) combined with ropivacaine for tranversus abdominis plane (TAP) block could improve analgesic quality and duration, and promote recovery following laparoscopic colectomy. Following induction of anesthesia, ultrasound-guided bilateral TAP block was performed in 60 patients scheduled for elective laparoscopic colectomy with either 20 ml of 0.375% ropivacaine plus 2 ml normal saline 0.9% (R group), or 20 ml of 0.375% ropivacaine plus 2 ml Dex (0.5 µg/kg) (RD group). Visual analogue scale (VAS) score for pain, sedation level, length of hospital stay (LOS), and bowel function recovery time and associated complications were recorded. Overall patient satisfaction with postoperative pain management was also assessed. The hemodynamic variables were not significantly different between the two groups during the surgery. However, the duration of analgesia was significantly longer in the RD group compared with the R group (P<0.05). VAS scores at 1, 2, 6 and 12 h following surgery were significantly decreased in the RD group compared with those in the R group (P<0.05). There was no significant difference in sedation level between the two groups. Notably, postoperative nausea and vomiting in the RD group was significantly decreased compared with those in the R group in the first 24 h (P<0.05). There were no serious adverse events in any group. Furthermore, 90.0 and 66.7% patients were satisfied with the postoperative pain management in the RD group and R group, respectively. The postoperative first bowel movement time was significantly shorter in the RD group compared with the R group (P<0.05). However, the LOS was not significantly different between the two groups. In conlusion, the addition of Dex to ropivacaine could significantly improve the analgesic quality and duration of TAP block, which in turn promotes recovery following laparoscopic colectomy.

Efficacy of dexmedetomidine in reducing post-operative pain and improving the quality of recovery in patients with burn wounds undergoing tangential excision skin grafting.

Burn-induced acute post-operative pain and the associated stress response may result in prolonged convalescence. The present study investigated the effects of dexmedetomidine (DEX) administration on post-operative pain and the quality of recovery following surgical treatment of moderate-to-severe burn injuries. A total of 60 adult patients undergoing tangential excision skin grafting were randomized into two groups. The DEX group (Group D) received an intravenous (i.v.) single-dose bolus injection of DEX 0.5 µg/kg >10 min prior to induction of anesthesia. Patient-controlled intravenous analgesia (PCIA) was provided to the patients from the end of the surgery, which consisted of 100 µg sufentanil plus 200 µg DEX. The control group (Group C) received an equal volume of normal saline as a pre-operative bolus and post-operative PCIA of 100 µg sufentanil infusion. The Visual Analogue Scale (VAS) score at rest and during movement, the cumulative dose of sufentanil and the 40-item quality of recovery questionnaire (QoR-40) score were assessed at various time-points after the surgery. During the first 24 h post-surgery, patients in Group D exhibited a lower VAS score at rest and during movement, a lower number of PCIA pump presses (29.17±1.91 vs. 34.13±2.73) and lower sufentanil consumption (62.58±0.96 vs. 65.27±1.26) compared with those in Group C (P<0.05). Furthermore, the QoR-40 recovery score of patients in Group D at 24 h post-surgery was higher compared with that in Group C (P<0.01). In conclusion, the present study indicated that a pre-operative bolus of DEX (0.5 µg/kg) followed by DEX plus sufentanil by PCIA subsequent to surgery improved the quality of analgesia and promoted the quality of recovery at 24 h following tangential excision skin grafting treatment of patients with moderate-to-severe burn injuries compared to PCIA of 100 µg sufentanil only. The present study was retrospectively registered with the trial registration no. ChiCTR1800016646 (date of registration, 14/06/2018).

Transversus abdominis plane block reduces remifentanil and propofol consumption, evaluated by closed-loop titration guided by bispectral index.

The present prospective, randomized, double-blind study aimed to determine the impact of transversus abdominis plane (TAP) block on propofol and remifentanil consumption, when administered by closed-loop titration guided by processed electroencephalography, i.e., bispectral index (BIS) values. Following institutional review board approval, 60 patients were scheduled for laparoscopic colectomy under general anesthesia. Patients were randomly assigned to receive bilateral TAP block with 20 ml 0.375% ropivacaine (TAP group) or 20 ml 0.9% saline [control (CON) group]. General anesthesia was maintained with propofol and remifentanil administration using closed-loop titration guided by BIS values. The primary outcome was perioperative propofol and remifentanil consumption. The secondary outcomes were hypertensive or hypotensive events requiring treatment, recovery time in PACU and time to first rescue analgesia following surgery. A total of 58 patients participated in the present study. At similar depths of anesthesia, as measured by BIS during the maintenance phase (45-55), patients who received TAP blocks required less propofol (4.2±1.3 vs. 5.5±1.6 mg/kg/h; P<0.001) and remifentanil (0.16±0.05 vs. 0.21±0.05 µg/kg/min; P<0.001). Time to extubation was significantly shorter in the TAP group (9.8±3.2 min) than in the CON group (14.2±4.9 min) (P<0.05). The requirement to treat hemodynamic change was also significantly lower (P<0.05). Pain score at 2 h after surgery was also significantly reduced in the TAP group compared with the CON group (P<0.05), whereas the time to first rescue analgesia was delayed in patients who received TAP block (P<0.05). Postoperative nausea and vomiting occurred at comparable rates in each group (P>0.05). In conclusion, TAP block combined with general anesthesia reduced propofol and remifentanil consumption, shortened time to tracheal extubation and promoted hemodynamic stability in laparoscopic colectomy.

Consciousness inhibition of intravenous dexmedetomidine in patients undergoing lower limb surgery with epidural anesthesia: A dose-response study by age group.

Dexmedetomidine (DEX) induces a dose dependent sedation and has been widely used as an adjuvant sedative during regional anesthesia recently. We aimed to investigate the effective dose of intravenous single-dose DEX to induce consciousness inhibition in patients of different ages undergoing lower limb surgery with epidural anesthesia. Ninety-two patients were divided into three groups according to their ages. Patients aged 18-45 years, 46-64 years and 65-85 years in group Y, group M and group O, respectively. With the accomplishment of epidural anesthesia, a pre-calculated dose of DEX was infused for more than 10 minutes and the sedative state was assessed by Observer's Assessment of Alertness/Sedation (OAA/S) scale 30 minutes after the infusion. A modified Dixon's up-and-down method was applied to decided the dose of DEX for each sequential patient. The 50% effective dose (ED50) of DEX in the three groups were 0.40, 0.76 and 1.03 µg/kg, respectively. The 95% effective dose (ED95) in group O (0.54 µg/kg) was 45% of group Y (1.21µg/kg) and 64% of group M (0.84µg/kg). Besides, the incidence of bradycardia was more frequent with the increase of age. The present study indicated that the appropriate single-dose of DEX to induce consciousness inhibition should reduce with the increase of age in patients undering lower limb surgery with epidural anesthesia, especially in patients over 64 years old. This result may protect the old patients from excessive sedation and dose-dependent adverse reactions.