Mary F. Chisholm

Transient Neurologic Symptoms after Spinal Anesthesia with Mepivacaine and Lidocaine

Background Spinal anesthesia with lidocaine is ideal for ambulatory surgery because of its short duration of action. However, transient neurologic symptoms (TNS) occur in 0–40% of patients. The incidence of TNS with mepivacaine, which has a similar duration of action, is unknown. Methods Sixty ambulatory patients undergoing knee arthroscopy received spinal anesthesia in a randomized, double‐blinded manner, with either 45 mg 1.5% mepivacaine or 60 mg 2% lidocaine. An L3‐L4 midline approach was used with a 27‐gauge Whitacre needle and a 20‐gauge introducer. The local anesthetic was injected over approximately 30 s with the aperture of the Whitacre needle in a cephalad direction. Two to 4 days after operation, each patient was questioned about the development of TNS. In addition, the two groups were compared for time to regression of sensory and motor blockade and time to discharge milestones. Results Three patients receiving lidocaine were lost to follow‐up. None of the 30 patients in the mepivacaine group developed TNS, whereas 6 of 27 (22%) in the lidocaine group did (P = 0.008). Time to regression to the L5 sensory level and to complete resolution of motor block were similar in both groups. The times to discharge milestones were also comparable. Conclusions The incidence of TNS is greater with 2% lidocaine than with 1.5% mepivacaine for patients having unilateral knee arthroscopy under spinal anesthesia. Mepivacaine seems to be a promising alternative to lidocaine for outpatient surgical procedures because of its similar duration of action. Further studies are warranted to determine the optimal dose of intrathecal mepivacaine for ambulatory surgery and the incidence of TNS with other doses and concentrations of intrathecal mepivacaine.

Are Postoperative Complications More Common with Single-Stage Bilateral (SBTKR) Than with Unilateral Knee Arthroplasty: Guidelines for Patients Scheduled for SBTKR

A significant number of patients with degenerative arthritis of the knee require bilateral knee arthroplasty. Single-stage bilateral total knee arthroplasty (SBTKR) has been associated with increased patient morbidity and mortality. At our institution, the following steps have been taken to minimize the risks to patients undergoing this procedure: regional anesthesia and analgesia, invasive monitoring, postoperative observation in an intensive care unit setting, and aggressive management of hemodynamic aberrations. We reviewed the medical records of 462 sequential total knee arthroplasty patients, consisting of 169 SBTKR and 293 unilateral total knee arthroplasty (UTKR) cases. A total of 122 patients from each group were matched for age, weight, and a history of ischemic heart disease and hypertension. Patients for SBTKR exhibited a significantly higher incidence of fat embolism syndrome and cardiac arrhythmias than UTKR patients. There were no deaths in either group and the incidence of other serious postoperative complications was low and similar between the two groups. Elderly patients (∼75 years old) had more postoperative complications. With aggressive clinical management SBTKR can be safely performed in selected patients. Guidelines for the selection of these patients are presented.

Dose response relationships for isobaric spinal mepivacaine using the combined spinal epidural technique

UNLABELLED Mepivacaine, a local anesthetic with similar physiochemical properties to those of lidocaine, is an adequate alternative for patients undergoing ambulatory procedures, and is associated with a lower incidence of transient neurologic symptoms (TNS) than lidocaine. We studied the dose-response characteristics of isobaric intrathecal mepivacaine using the combined spinal epidural technique for patients undergoing ambulatory arthroscopic surgery of the knee. Seventy-five patients were randomized prospectively to receive one of three doses of isobaric mepivacaine for spinal anesthesia: 30 mg (2 mL 1.5%), 45 mg (3 mL 1.5%), or 60 mg (4 mL 1.5%). An observer, blinded to the dose, recorded sensory level to pinprick and motor response until resolution of the block. In addition, the incidence of TNS was determined. An initial intrathecal dose of 30 mg of isobaric mepivacaine 1.5% produced satisfactory anesthesia in 72% of ambulatory surgical patients undergoing unilateral knee arthroscopy with a significantly shorter duration of sensory (158 +/- 32 min) and motor blockade (116 +/- 38 min) than doses of 45 and 60 mg. An intrathecal dose of 45 mg produced satisfactory anesthesia in all patients with a shorter duration of sensory (182 +/-38 min) and motor blockade (142 +/- 37 min) than 60 mg of mepivacaine 1.5% (203 +/- 36 min and 168 +/- 36 min, respectively). The incidence of TNS was 7.4% overall (1.2%-13.6% confidence intervals), less than the rates previously reported after spinal anesthesia with lidocaine in ambulatory surgical patients undergoing knee arthroscopy. We conclude that mepivacaine can be used as an adequate alternative to lidocaine for ambulatory procedures. IMPLICATIONS This study evaluated the postoperative duration of spinal anesthesia after varying doses of isobaric mepivacaine and the incidence of transient radiating back and leg pain. We found that 45 mg of mepivacaine provided adequate anesthesia, a timely discharge, and a lower incidence of back pain than that previously reported after lidocaine spinals.

Fear in Perspective

1040 May 2018 II review the patient’s chart. I enter the room and step around the curtain where she waits, ready for her operation. She is comfortably chatting with her grown son and daughter. Her elderly husband leans on his cane, head tilted to catch all the conversation. Views of the sun-dappled East River calm the mind. Introductions are made, medical history reviewed. My patient says: “So, if I make it, after this, I’ll have a new hip.” Her husband leans back; son and daughter move in. “Tell me more,” I say, “What do you mean, ‘If I make it’?” “Well, you know,” she says, her eyes tearing, “If I make it...” “Why wouldn’t you make it?” I ask. “Do you have a sense about something that you’re not saying?” acknowledging that people sometimes do have a premonition about something going terribly wrong. “I’ve just never been sick before.” She fights back tears. Stephen T. Harvey, M.D., Editor