Irina Gasanova

Effect of auditory evoked potential index monitoring on anesthetic drug requirements and recovery profile after laparoscopic surgery: A clinical utility study

Background The auditory evoked potential (AEP) monitor provides an electroencephalogram-derived index (AAI) that has been reported to correlate with the central nervous system depressant effects of anesthetic drugs. This clinical utility study was designed to test the hypothesis that AAI-guided administration of the maintenance anesthetics and analgesics would improve their titration and thereby provide a faster recovery from general anesthesia. Methods Seventy consenting patients undergoing elective general surgery procedures were randomly assigned to either a control (standard clinical practice) or AEP-monitored group. Although the AEP monitor was connected to all patients, the information from the monitor was only made available to the anesthesiologists assigned to patients in the AEP-monitored group. In the AEP-monitored group, the inspired desflurane concentration was titrated to maintain an AAI value of 15–20. In the control group, the inspired desflurane concentration was varied based on standard clinical signs. The AAI values and hemodynamic variables, as well as end-tidal desflurane concentrations, were recorded at 3- to 5-min intervals. The recovery times to achieve a White fast-track score greater than 12 and an Aldrete score of 10, as well as the actual duration of the PACU stay, were evaluated at 5- to 10-min intervals. Patient satisfaction with recovery from anesthesia was assessed using a 100-point verbal rating scale at 24 h after surgery. Results The average intraoperative AAI value in the AEP-monitored group was significantly higher than in the control group (16 ± 5 vs. 11 ± 8, P < 0.05). Use of the AEP monitor reduced the desflurane requirement by 26% compared to the control group (P < 0.01). In addition, the AEP-monitored group received less intraoperative fentanyl (270 ± 120 vs. 390 ± 203 &mgr;g, P < 0.05) and more rapidly achieved fast-track eligibility (29 ± 19 vs. 56 ± 41 min, P < 0.05). The time required to achieve an Aldrete score of 10 (60 ± 31 vs. 98 ± 55 min) and the duration of stay in the recovery room (78 ± 32 vs. 106 ± 54 min) were also significantly reduced in the AEP-monitored (vs. control) group (P < 0.05). Conclusion Use of AEP monitoring as an adjunct to standard clinical monitors improved titration of anesthetic drugs, thereby facilitating the early recovery process after laparoscopic surgery.

Transversus Abdominis Plane Block Versus Surgical Site Infiltration for Pain Management After Open Total Abdominal Hysterectomy.

BACKGROUND:Surgical site infiltration and transversus abdominis plane (TAP) blocks are commonly used to improve pain relief after lower abdominal surgery. This randomized, observer-blinded study was designed to compare the analgesic efficacy of TAP blocks with surgical site infiltration in patients undergoing open total abdominal hysterectomy via a Pfannenstiel incision. METHODS:Patients were randomized to receive either bilateral ultrasound-guided TAP blocks using bupivacaine 0.5% 20 mL on each side (n = 30) or surgical site infiltration with liposomal bupivacaine 266 mg diluted to 60 mL injected in the preperitoneal, subfascial, and subcutaneous planes (n = 30). The remaining aspects of the perioperative care were standardized. An investigator blinded to the group allocation documented pain scores at rest and with coughing, opioid requirements, nausea, vomiting, and rescue antiemetics in the postanesthesia care unit and at 2, 6, 12, 24, and 48 hours postoperatively. The primary outcome measure was pain scores on coughing at 6 hours postoperatively. RESULTS:One patient in each group was excluded from the analysis because of reoperation within 24 hours in the TAP block group and change of incision type in the infiltration group. The pain scores at rest and with coughing were significantly lower in the surgical site infiltration group at all postoperative time points (P < 0.0001) except at rest in the postanesthesia care unit. The opioid requirements between 24 and 48 hours were significantly lower in the infiltration group (P = 0.009). The nausea scores, occurrence of vomiting, and need for rescue antiemetics were similar. CONCLUSIONS:Surgical site infiltration provided superior pain relief at rest and on coughing, as well as reduced opioid consumption for up to 48 hours. Future studies need to compare TAP blocks with liposomal bupivacaine with surgical site infiltration with liposomal bupivacaine.

Anesthesia for Kidney Transplantation-A Review

Kidney transplant anesthesia can be a mentally challenging yet rewarding aspect of the anesthesiologist’s job. End stage renal disease (ESRD) patients tend to have a medical history that leads to very complex physiology. In this article we will review the pathophysiology of ESRD, the effects of ESRD on other body systems, and how it effects the perioperative management of the ESRD patient.

Clonidine, but not dexamethasone, prolongs ropivacaine-induced supraclavicular brachial plexus nerve block duration

BACKGROUND Ultrasound-guided supraclavicular brachial plexus block (USSB) provides excellent postoperative analgesia after upper extremity surgery. Dexamethasone and clonidine have been added to local anesthetics to enhance and prolong the duration of analgesia. OBJECTIVE The objective of this randomized prospective study is to evaluate the efficacy of dexamethasone, clonidine, or combination of both as adjuvants to ropivacaine on the duration of USSB for postoperative analgesia. METHODS Patients receiving USSB for postoperative pain control for upper extremity surgery were randomized to one of four groups; ropivacaine 0.5%, ropivacaine 0.5% with 4 mg dexamethasone, ropivacaine 0.5% with 100 mcg clonidine , or ropivacaine 0.5% with 4 mg dexamethasone and 100 mcg clonidine. Pain scores, sensory and motor function were evaluated at post anesthesia care unit (PACU), discharge and at 24 h postoperatively. RESULTS The duration of sensory and motor blocks was significantly longer in clonidine groups when compared to ropivacaine alone [Sensorial analgesia: ropivacaine alone 13.4±6, Ropivacaine- Clonidine 17.4±6; Ropivacaine-Dexamethasone-Clonidine 18.8±6.2; Motor blocks: Ropivacaine 12±5, Ropivacaine-Clonidine 16.8±5.2, Ropivacaine-Dexamethasone-Clonidine 18.2±5.7]. In clonidine groups, there was significant prolongation of motor and sensory block when compared to ropivacaine group alone. CONCLUSION The results demonstrated that clonidine significantly prolongs the duration of ropivacaine effects for the postoperative analgesia in patient underwent upper arm surgeries.

Effects of fentanyl administration before induction of anesthesia and placement of the Laryngeal Mask Airway: a randomized, placebo-controlled trial

STUDY OBJECTIVE To assess the effects of fentanyl administered before induction of anesthesia on movement and airway responses during desflurane anesthesia via the Laryngeal Mask Airway (LMA). DESIGN Randomized, double-blinded, controlled trial. STUDY SETTING Tertiary-care academic center. PATIENTS 100 adult, ASA physical status 1, 2, and 3 patients undergoing ambulatory surgery. INTERVENTIONS Patients were administered fentanyl 1 μg/kg (n=51) or saline (n=49) 3 to 5 minutes before induction with propofol 2-2.5 mg/kg intravenously (IV), followed by LMA placement. Anesthesia was maintained with desflurane titrated to a bispectral index (BIS) of 50-60 and 50% nitrous oxide in oxygen, and fentanyl 25 μg boluses were titrated to respiratory rate. MEASUREMENTS Apnea occurrence and duration of manual ventilation, as well as frequency and severity of movement, coughing, breath holding, and laryngospasm were recorded. MAIN RESULTS Two patients in each group were excluded from analysis. The fentanyl pretreatment group had a higher frequency of apnea (94% vs 64%; P=0.0003) and longer duration of manual ventilation (3 [interquartile range (IQR), 1.5-5] min vs 1 [0-1.5] min; P<0.0001) at induction. In contrast, the fentanyl pretreatment group had a lower frequency of movements (16% vs 51%;P=0.0001). The rates of intraoperative breath holding (6.1% vs 8.5%) and laryngospasm (2% vs 4.3%) in the two groups were similar. All subjects experiencing laryngospasm were smokers. Adjusting for smoking status did not affect the differences noted in apnea, duration of manual ventilation, or movement between groups; however, coughing occurrence was statistically higher in the placebo group (P=0.043). CONCLUSIONS Preinduction fentanyl increased the frequency of apnea at induction and duration of manual ventilation, but reduced the frequency of movements. In addition, it reduced intraoperative coughing in smokers.

Platelet Aggregometry May Not Identify Clopidogrel-Treated Patients at High Risk of Peri-Operative Bleeding in Dialysis Access Surgery: A Pilot Study

Patients treated with Clopidogrel are usually instructed to discontinue treatment for 7 days prior to surgery because of concern for excessive peri-operative blood loss. Limited data exist regarding blood loss resulting from continuing treatment with Clopidogrel. Our goal was to compare peri-operative blood loss in Clopidogrel (CC) treated patients with Non-Clopidogrel (NC) patients undergoing upper extremity dialysis access surgery. Methods: Following informed consent, 23 patients, 18-90 years old were enrolled in a pilot, prospective study. Nine patients continued treatment with Clopidogrel, while 14 patients had no exposure to the drug. Vascular fistula or graft placement was accomplished under brachial plexus anesthesia and sedation. ADP (adenosine diphosphate) induced inhibition of platelets was assayed by Impedance-based Whole Blood Platelet Aggregation (IWBPA) on immediate preoperative blood sample obtained from all participants to determine baseline platelet aggregation status (Figure 1). Intra-operative blood loss (IBL) was estimated from suction canister output and sponge weights. Interventions such as blood or blood product transfusion were noted. Postoperative bruising or bleeding for up to 24 hours was recorded.