Choice of anesthesia and intraoperative monitoring for lower extremity revascularization

Utilization and Outcomes of Local Anesthesia and Peripheral Nerve Block for Hybrid Lower Extremity Revascularization

Purpose: To investigate the utilization of local anesthesia or peripheral nerve block with monitored anesthesia care (LPMAC) and its impact on the perioperative outcomes of hybrid lower extremity revascularization (LER) compared with general anesthesia (GA). Materials and Methods: A search of the ACS-NSQIP database between 2005 and 2017 identified 9430 patients who underwent hybrid LER for peripheral artery disease. Excluding 449 ineligible cases left 8981 hybrid LER patients for analysis. The patients were dichotomized based on the anesthetic technique: 8631 (96.1%) GA and 350 (3.9%) LPMAC. The GA patients were matched 3:1 based on propensity scores to patients in the LPMAC group based on gender, age, race, functional status, transfer status, chronic obstructive pulmonary disease (COPD), dialysis status, American Society of Anesthesiologists (ASA) class, emergent surgery, preoperative sepsis, indication, and type of open and endovascular procedure. Outcomes including complications, mortality, procedure time, and hospital length of stay were compared between the matched groups (801 GA vs 267 LPMAC). Results: Comparing the unmatched groups, those treated under LPMAC were older (72.7±9 vs 68±8.4 years, p<0.001) and had higher rates of COPD (24.3% vs 17%, p=0.001), dialysis dependence (8.1% vs 4.2%, p=0.002), preoperative sepsis (6.6% vs 4.2%, p=0.029), and ASA class ≥IV (29.1% vs 24.1%, p=0.036) than in the unmatched GA cohort. In the matched comparison, LPMAC was associated with lower overall morbidity (25.5% vs 32.3%, p=0.042) and shorter operating time (202.7±98 vs 217.7±102 minutes, p=0.034) compared with GA. The rate of myocardial infarction was lower (1.1% vs 2.4%) and ventilator use for >48 hours was less frequent (0.4% vs 2.6%) for LPMAC patients, though statistical significance was not reached. There was no difference in mortality or hospital length of stay. Conclusion: LPMAC is an infrequent anesthetic technique for hybrid LER and is primarily used for patients with a high burden of comorbidities. LPMAC is associated with reduced overall morbidity and operating time. Further studies are needed to identify which patients undergoing hybrid LER benefit most from LPMAC.

Continuous spinal microcatheter (28 gauge) technique for arterial bypass surgery of the lower extremities and comparison of ropivacaine with or without morphine for postoperative analgesia †

BACKGROUND

The aim of this study was to evaluate a microcatheter technique for continuous spinal anaesthesia (CSA) and continuous spinal postoperative analgesia (CSPA) in vascular surgery.

METHODS

A total of 47 patients (range 51-95 yr, ASA II-IV) undergoing peripheral bypass surgery of the lower extremities received a spinal microcatheter (28 gauge) at L3-L4 or L2-L3. For CSA, ropivacaine 7.5 mg ml(-1) was given in small increments. Central venous pressure was maintained >or=3 mm Hg. Of 47 patients, 44 received CSPA, either using ropivacaine alone 2 mg h(-1) (group R, n=22) or ropivacaine 1 mg h(-1) with morphine 8 microg h(-1) (group RM, n=22) for 24 h after surgery (randomized, double-blinded).

RESULTS

Intraoperative haemodynamic control was good; during the initial 60 min only four patients received phenylephrine i.v. for hypotension. Up to 30% of the patients felt mild pain at incision but surgery [mean duration 173 min (range 66-327)] was successfully completed under CSA in 45 patients. In four instances of acute revision surgery, a new block was administered utilizing the spinal catheter in place. Postoperative pain relief was comparably adequate in both groups with no difference in rescue pain medication. Four patients (three in R, one in RM) had weak motor blockade in the first postoperative morning.

CONCLUSIONS

The described CSA technique offered good haemodynamic control, ease of maintaining spinal anaesthesia, and ease of providing a new spinal block for revision. The combination of low-dose ropivacaine and morphine for CSPA did not offer any benefit compared with the higher ropivacaine dose alone.

Intraoperative management: peripheral vascular surgery

Lower extremity atherosclerotic disease affects nearly 10 million people in the United States. Recent advances in diagnostic imaging and interventional techniques help many patients avoid more invasive surgical procedures. Those reaching the operating room, however,represent a distilled subset of patients who are prone to significant comorbidities. We outline current treatment strategies and discuss anesthetic concerns and techniques for these complex patients.