Neuraxial opioids in geriatrics: A dose reduction study of local anesthetic with addition of sufentanil in lower limb surgery for elderly patients

Neuraxial Anesthesia in the Geriatric Patient

Neuraxial anesthesia is recommended as a well-accepted option to minimize the perioperative side effects in the geriatric patients. The available data from the current researches have shifted the focus from the conventional approach to spinal anesthesia to the concept of low dose local anesthetic combined with opioids. What remains clear from all these studies is that hemodynamic stability is much better in patients who received low-doses of intrathecal bupivacaine in combination with opioids, which is possibly result of a potent synergistic nociceptive analgesic effect and their minimal potential effects on sympathetic pathways thus minimizing spinal hypotension. Spinal anesthesia with 5–10 mg of 0.5% heavy bupivacaine, fentanyl 20 mcg and 100 mcg of long-acting morphine added to the perioperative plan decreased the incidence of spinal hypotension and improved perioperative outcomes in the geriatric patients undergoing (low segment) surgical procedures. These findings may be of interest in the gynecologic geriatric surgery also in which area there are very few studies concerning the use of low-dose concept.

Intravenous dexmedetomidine as an adjunct to subarachnoid block: A simple effective method of better perioperative efficacy

BACKGROUND AND AIM

Dexmedetomidine (D) is a α2 agonist, has anesthetic and analgesic-sparing property. The objective of this study was to evaluate the effect of intravenous (I.V.) dexmedetomidine on the duration of sensory and motor block, postoperative analgesia, the level of sedation and side effect.

MATERIAL AND METHODS

Sixty patients were randomly divided into two groups of thirty each. Group D received dexmedetomidine infusion @1 mcg/kg over 10 min and then @ 0.6 mcg/kg/h for rest of duration during surgery, Group C (control) received a similar volume of normal saline infusion before spinal anesthesia with 3 ml of bupivacaine 0.5%. Time of onset and regression time for sensory and motor blockade, the maximum upper level of sensory blockade, duration of postoperative analgesia, Ramsay sedation score and hemodynamic parameters were recorded. Intraoperative bradycardia and atropine requirement along with other side effect were also recorded.

RESULTS

The duration of sensorimotor block was significantly longer in D Group (341.7 ± 20.8 min for sensory block and 278.0 ± 11.0 min for motor block) as compared to control group (329.5 ± 22.1 min for sensory block and 250.0 ± 14.8 min for motor block), which was statistically significant (P < 0.05). The mean time for two dermatomal regression of sensory blockade was significantly prolonged in dexmedetomidine group (115.5 ± 8.7 min) compared to control group (95.8 ± 11.4) (P < 0.001). Intraoperative Ramsay sedation scores were significantly higher in D Group (mean - 3.4 ± 0.7, range - 2-4) as compared to C Group (mean - 2.9 ± 0.3, range - 2-4) (P < 0.001). 26.7% (8/30) cases had bradycardia that required atropine as compared to control group (2/30), and none of the patients in the dexmedetomidine group had postoperative shivering as compared to 10% in control group (P = 0.056). Statistical analysis was performed with statistical package for the social science version-20 using analysis of variance/Chi-square test/unpaired t-test, and P < 0.05 was considered statistically significant.

CONCLUSION

I.V. dexmedetomidine significantly prolongs the duration of sensory and motor block of bupivacaine spinal anesthesia. Dexmedetomidine provides an excellent sedation during surgery.

Anaesthesia for laparoscopic surgery: General vs regional anaesthesia

The use of laparoscopy has revolutionised the surgical field with its advantages of reduced morbidity with early recovery. Laparoscopic procedures have been traditionally performed under general anaesthesia (GA) due to the respiratory changes caused by pneumoperitoneum, which is an integral part of laparoscopy. The precise control of ventilation under controlled conditions in GA has proven it to be ideal for such procedures. However, recently the use of regional anaesthesia (RA) has emerged as an alternative choice for laparoscopy. Various reports in the literature suggest the safety of the use of spinal, epidural and combined spinal-epidural anaesthesia in laparoscopic procedures. The advantages of RA can include: Prevention of airway manipulation, an awake and spontaneously breathing patient intraoperatively, minimal nausea and vomiting, effective post-operative analgesia, and early ambulation and recovery. However, RA may be associated with a few side effects such as the requirement of a higher sensory level, more severe hypotension, shoulder discomfort due to diaphragmatic irritation, and respiratory embarrassment caused by pneumoperitoneum. Further studies may be required to establish the advantage of RA over GA for its eventual global use in different patient populations.

Intrathecal Sufentanil Does Not Reduce Shivering During Neuraxial Anesthesia: A Meta-Analysis

BACKGROUND

We performed this meta-analysis to evaluate the efficacy of intrathecal sufentanil in preventing shivering during neuraxial anesthesia.

MATERIAL/METHODS

We searched the Cochrane Library, PubMed, and Embase for all randomized controlled trials (RCT) on use of intrathecal sufentanil for preventing shivering during neuraxial anesthesia. References of retrieved articles were also screened. The quality of the studies was evaluated by the method recommended by the Cochrane Collaboration. Meta-analysis was conducted using the Cochrane Collaboration's RevMan 5.3 software. The primary outcome was incidence and severity of shivering, and the secondary outcomes were drug-related complications of pruritus, nausea, vomiting, hypotension, and bradycardia.

RESULTS

Eight original RCTs investigating a total of 1032 patients, of whom 599 received sufentanil and 473 received placebo, met the inclusion criteria. Compared to the placebo group, sufentanil did not reduce incidence of shivering (OR, 0.60; 95% CI, 0.35 to 1.01; P=0.06), but it increased the incidence of pruritus (OR, 12.52; 95% CI, 5.07 to 30.91; P<0.00001). Compared to the placebo group, sufentanil did not increase the incidence of nausea (OR, 0.69; 95% CI, 0.41 to 1.16; P=0.16), hypotension (OR, 0.93; 95% CI, 0.62 to 1.41; P=0.74), or bradycardia (OR, 0.86; 95% CI, 0.41 to 1.82; P=0.70). In addition, sufentanil reduced the incidence of vomiting during neuraxial anesthesia (OR, 0.45; 95% CI, 0.22 to 0.92; P=0.03).

CONCLUSIONS

Neither epidural nor subarachnoid intrathecal sufentanil reduced shivering during neuraxial anesthesia, but it did increase the incidence of pruritus.

Predictors of acute kidney injury in geriatric patients undergoing total knee replacement surgery

BACKGROUND

Few studies have focused on patients' characteristics that affects acute kidney injury (AKI) after total knee replacement surgery (TKR).

OBJECTIVES

The primary objective of this retrospective study was to identify patients' characteristics associated with AKI after TKR.

PATIENTS AND METHODS

Between January 2008 and December 2009, 659 patients with a mean age of 67.1 years (range, 39-99) underwent TKA at Regional Hospital Knee and Hip Institute. Retrospective chart review was done to identify patients' characteristics that were associated with AKI after TKR. Logistic regression was used to evaluate AKI.

RESULTS

AKI occurred in 21.9% of patients. AKI risk decreased between 2008 and 2009 (odds ratio, 0.55; 95% CI, -0.37 to 0.82) but increased with age (P < 0.001), diabetes mellitus (DM), and angiotensin converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) use (OR, -1.6; 95% CI, -1.0 to 2.5; and OR, -1.5, 95% CI, -1.0 to 2.3, respectively). However, the effects of DM and ACEI/ARB use were not independent; when both were included in the regression model, neither was statistically significant, and both ORs were smaller than combined OR.

CONCLUSIONS

When examined separately, both DM and preoperative ACEI/ARB use increased the risk of AKI; however these factors were correlated and were not independent predictors of significantly increased risk. Patients with DM have higher tendency to develop AKI and hence, preoperative renal risk stratification should be done in all patients with DM.