Hans P. Sviggum

Perioperative nerve injury after total knee arthroplasty: regional anesthesia risk during a 20-year cohort study.

BACKGROUND Perioperative nerve injury (PNI) is a recognized complication of total hip arthroplasty (THA). Regional anesthesia (RA) techniques may increase the risk of neurologic injury. Using a retrospective cohort study, the authors tested the hypothesis that use of RA increases the risk for PNI after elective THA. METHODS All adult patients who underwent elective THA at Mayo Clinic during a 20-yr period were included. The primary outcome was the presence of a new PNI within 3 months of surgery. Multivariable logistic regression was used to evaluate patient, surgical, and anesthetic risk factors for PNI. RESULTS Of 12,998 patients undergoing THA, 93 experienced PNI (incidence = 0.72%; 95% CI 0.58-0.88%). PNI was not associated with type of anesthesia (OR = 0.72 for neuraxial-combined vs. general; 95% CI 0.46-1.14) or peripheral nerve blockade (OR = 0.65; 95% CI 0.34-1.21). The risk for PNI was associated with younger age (OR = 0.79 per 10-yr increase; 95% CI 0.69-0.90), female gender (OR = 1.72; 95% CI 1.12-2.64), longer operations (OR = 1.10 per 30-min increase; 95% CI 1.03-1.18) or posterior surgical approach (OR = 1.91 vs. anterior approach; 95% CI 1.22-2.99). Neurologic recovery was not influenced by the use of RA techniques in patients with PNI. CONCLUSIONS The risk for PNI after THA was not increased with the use of neuraxial anesthesia or peripheral nerve blockade. Neurologic recovery in patients who experienced PNI was not affected by the use of RA. These results support the use of RA techniques in patients undergoing elective THA given their known functional and clinical benefits.

Neurologic complications after chlorhexidine antisepsis for spinal anesthesia

Background and Objectives Recent reports of infectious complications after neuraxial procedures highlight the importance of scrupulous aseptic technique. Although chlorhexidine gluconate (CHG) has several advantages over other antiseptic agents; including a more rapid onset of action, an extended duration of effect, and rare bacterial resistance, it is not approved by the US Food and Drug Administration for use before lumbar puncture because of absence of clinical safety evidence. The objective of this retrospective cohort study was to test the hypothesis that the incidence of neurologic complications associated with spinal anesthesia after CHG skin antisepsis is not different than the known incidence of neurologic complications associated with spinal anesthesia. Methods All patients 18 years or older who underwent spinal anesthesia at Mayo Clinic Rochester from 2006 to 2010 were identified. The primary outcome variable was the presence of any new or progressive neurologic deficit documented within 7 days of spinal anesthesia. The etiology of a patient’s neurologic complication was independently categorized as possibly or unlikely related to the spinal anesthetic by 3 investigators. Consensus among all reviewers was required for final category assignment. Results A total of 11,095 patients received 12,465 spinal anesthetics during the study period. Overall, 57 cases (0.46%; 95% confidence interval, 0.34%–0.58%) met criteria for neurologic complication. Spinal anesthesia was felt to be the possible etiology of 5 neurologic complications (0.04%; 95% confidence interval, 0.00%–0.08%); all completely resolved within 30 days. Discussion The incidence of neurologic complications possibly associated with spinal anesthesia (0.04%) after CHG skin antisepsis is consistent with previous reports of neurologic complications after spinal anesthesia. These results support the hypothesis that CHG can be used for skin antisepsis before spinal placement without increasing the risk of neurologic complications attributed to the spinal anesthetic.

Perioperative nerve injury after total shoulder arthroplasty: assessment of risk after regional anesthesia.

Background and Objectives One of the most debilitating complications after total shoulder arthroplasty (TSA) is perioperative nerve injury (PNI). Interscalene blockade (ISB) improves clinical outcomes after TSA, but it may increase the risk for PNI. The objective of this large-scale, single-institution cohort study was to test the hypothesis that the use of ISB increases the risk for PNI after elective TSA. Methods All patients 18 years and older and undergoing primary elective TSA at Mayo Clinic Rochester between 1993 and 2007 were identified. The primary outcome was the presence of new PNI documented within 3 months of the procedural date. The frequency of PNI was summarized using point estimates, along with 95% confidence intervals (CIs) that were calculated using the Poisson approximation. Multivariable logistic regression was used to evaluate potential risk factors for PNI. Results A total of 1569 patients underwent elective TSA during the study period; 35 cases met criteria for PNI. The overall incidence of PNI was 2.2% (95% CI, 1.6%–3.1%). Use of ISB was associated with reduced odds for PNI (odds ratio [OR], 0.47; 95% CI, 0.24–0.93; P = 0.031). Sex (OR, 0.85; P = 0.645) and operative time (OR, 1.07 per 30-minute increase; P = 0.263) were not associated with PNI. Most patients with PNI (97%) experienced complete or partial neurologic recovery at last documentation. Conclusions The incidence of PNI (2.2%) is consistent with previous estimates in patients undergoing TSA. The use of ISB did not increase the risk for PNI. Most patients with PNI had improvement of their neurologic symptoms. These results further support the use of ISB analgesia for patients undergoing TSA.

Needle Echogenicity in Sonographically Guided Regional Anesthesia Blinded Comparison of 4 Enhanced Needles and Validation of Visual Criteria for Evaluation

Needle visualization is important for sonographically guided regional anesthesia procedures. Needle characteristics that improve needle visualization are therefore important to anesthesiologists. This study compared several echogenic needle designs by defining characteristics of needle echogenicity and assessing regional anesthesiologist preferences for these characteristics across various needle angles.

Maternal Anesthesia for Fetal Surgery

This article describes the anesthetic management of pregnant women undergoing fetal surgery. Discussion includes general principles common to all fetal surgeries as well as specifics pertaining to open fetal surgery, minimally invasive fetal surgery, and ex utero intrapartum therapy (EXIT) procedures.

Autonomic Cardiovascular Control During a Novel Pharmacologic Alternative to Ganglionic Blockade

The purpose of this study was to compare ganglionic blockade with trimethaphan (TMP) and an alternative drug strategy using combined muscarinic antagonist (glycopyrrolate, GLY) and α‐2 agonist (dexmedetomidine, DEX). Protocol 1: incremental phenylephrine was administered during control and combined GLY‐DEX, or control and TMP on two control combined GLY and DEX or TMP infusion on two randomized days. Protocol 2: muscle sympathetic nerve activity (MSNA) and the baroreflex MSNA relationship was determined before and after GLY–DEX. Blood pressure was higher with GLY–DEX (99±3 mm Hg) and lower with TMP (78±3 mm Hg) relative to control (GLY–DEX: 90±2 mm Hg; TMP: 91±2 mm Hg;P<0.05). Incremental phenylephrine increased pressure during GLY–DEX (P<0.01 vs control) and TMP (P<0.01 vs control) to a similar degree. Both GLY–DEX and TMP infusion inhibited norepinephrine release (P<0.01 vs control). GLY–DEX inhibited baseline MSNA (P<0.05) and baroreflex changes in MSNA (P<0.01). We conclude that the GLY–DEX alternative drug strategy can be used as a reasonable alternative to pharmacologic ganglionic blockade to examine autonomic cardiovascular control.

Cesarean delivery in the hybrid operating suite: a promising new location for high-risk obstetric procedures.

BACKGROUND: The increasing cesarean delivery rate and attendant placental implantation abnormalities, coupled with increasing general medical complexity in the obstetric population, has driven innovation to optimize the care of high-risk parturients during delivery. Novel and multidisciplinary approaches and locations may enhance the options available for care. METHODS: We reviewed the records of all 11 patients who underwent cesarean delivery in our hybrid operating suite between December 2007 and March 2013 and describe the high-risk cesarean deliveries. RESULTS: The most common indication for the use of the hybrid operating suite was an increased risk of hemorrhage, most commonly due to abnormal placental implantation. Other indications included cardiovascular disease and intracranial pathology. CONCLUSION: The hybrid operating suite may be an alternative location for obstetric delivery, and our experience suggests that this environment may prove advantageous for patients with a variety of comorbid conditions. 

Continuous Posterior Lumbar Plexus Nerve Block Versus Periarticular Injection with Ropivacaine or Liposomal Bupivacaine for Total Hip Arthroplasty: A Three-Arm Randomized Clinical Trial

Background: Debate surrounds the issue of whether peripheral nerve blockade or periarticular infiltration (PAI) should be employed within a contemporary, comprehensive multimodal analgesia pathway for total hip arthroplasty. We hypothesized that patients treated with a continuous posterior lumbar plexus block (PNB) would report less pain and consume less opioid medication than those treated with PAI. Methods: This investigator-initiated, independently funded, 3-arm randomized clinical trial (RCT) performed at a single high-volume institution compared postoperative analgesia interventions for elective, unilateral primary total hip arthroplasty: (1) PNB; (2) PAI with ropivacaine, ketorolac, and epinephrine (PAI-R); and (3) PAI with liposomal bupivacaine, ketorolac, and epinephrine (PAI-L) using computerized randomization. The primary outcome was maximum pain during the morning (06:00 to 12:00) of the first postoperative day (POD) on an ascending numeric rating scale (NRS) from 0 to 10. Pairwise treatment comparisons were performed using the rank-sum test, with a p value of <0.017 indicating significance (Bonferroni adjusted). A sample size of 150 provided 80% power to detect a difference of 2.0 NRS units. Results: We included 159 patients (51, 54, and 54 patients in the PNB, PAI-R, and PAI-L groups, respectively). No significant differences were found with respect to the primary end point on the morning of the first POD (median, 3.0, 4.0, and 3.0, respectively; p > 0.033 for all). Opioid consumption was low and did not differ across groups at any intervals. Median maximum pain on POD 1 was 5.0, 5.5, and 4.0, respectively, and was lower for the PAI-L group than for the PAI-R group (p = 0.006). On POD 2, maximum pain (median, 3.5, 5.0, and 3.5, respectively) was lower for the PNB group (p = 0.014) and PAI-L group (p = 0.016) compared with the PAI-R group. The PAI-L group was not significantly different from the PNB group with respect to any outcomes: postoperative opioid use including rescue intravenous opioid medication, length of stay, and hospital adverse events, and 3-month follow-up data including any complication. Conclusions: In this RCT, we found a modest improvement with respect to analgesia in patients receiving PNB compared with those receiving PAI-R, but not compared with those who had PAI-L. Secondary analyses suggested that PNB or PAI-L provides superior postoperative analgesia compared with PAI-R. For primary total hip arthroplasty, a multimodal analgesic regimen including PNB or PAI-L provides opioid-limiting analgesia. Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

A rare combination of undiagnosed hypertrophic cardiomyopathy revealed by intraoperative anaphylaxis resulting in acute left ventricular outflow obstruction and cardiac arrest.

A 75-year-old female presented for left total hip reimplantation and suffered pulseless electrical activity arrest upon lateral positioning and administering vancomycin. Resuscitation was achieved according to Advanced Cardiac Life Support protocol. Post-event echocardiography showed hypertrophic cardiomyopathy with asymmetrical septal thickening, an under-filled left ventricle, dynamic left ventricular outflow obstruction, and severe mitral regurgitation related to systolic anterior motion of the mitral valve. Laboratory analysis showed a tryptase level of 209 ng/mL. After multispecialty evaluation, it was concluded that the patients arrest was due to vancomycin anaphylaxis in the setting of previously undiagnosed hypertrophic cardiomyopathy leading to acute left ventricular outflow tract obstruction. After medical optimization of the patients cardiomyopathy and an evaluation of potential intraoperative allergic triggers, the patient underwent a successful hip reimplantation without incident. This case presents a novel combination of events leading to intraoperative cardiac arrest. Rapid identification and an understanding of the cause(s) of cardiac arrest in this setting are critical for effective perioperative care.

Perioperative Nerve Injury after Peripheral Nerve Block in Patients with Previous Systemic Chemotherapy

Background and Objectives There are multiple risk factors for developing perioperative nerve injury (PNI). Perioperative nerve injury after peripheral nerve blockade (PNB) is rare. Exposure to systemic chemotherapy may cause peripheral neuropathy, but its role as a risk factor for PNI after PNB is unknown. The objective of this retrospective study was to determine the incidence of PNI in patients undergoing PNB as part of extremity surgery after prior exposure to systemic chemotherapy. Methods All patients aged 18 years or older who received systemic chemotherapy and subsequently underwent PNB were identified. The primary outcome was defined as the presence of new or worsened PNI documented within 3 months of the procedural date. Cases of PNI were independently reviewed by 3 investigators, and the etiology of all PNI cases were categorized as possibly or unlikely related to the PNB. Results A total of 216 PNB (165 lower extremity blocks, 51 upper extremity blocks) were performed in 186 patients previously exposed to chemotherapy; 4 cases met criteria for PNI (2.2%; 95% confidence interval, 0.8%–5.4%). One case of PNI was possibly related to PNB (0.5%; 95% confidence interval, 0.1%–3.0%) and 3 cases were unlikely related to PNB. Complete recovery occurred in 3 cases, with partial recovery occurring in 1. Conclusions The overall incidence of PNI in this cohort (2.2%) was not different than baseline risk established in large cohort studies. Perioperative nerve injury was possibly attributable to the PNB in 0.5% of patients. However, in the absence of a control group of surgical patients who previously received systemic chemotherapy without regional anesthesia, we cannot determine whether the higher incidence of neurologic injury is secondary to the surgical procedure, the anesthetic technique, the natural progression of chemotherapy-induced peripheral neuropathy, or a combination of factors and the relative contribution of each.