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Introduction Sub-anesthetic ketamine is frequently used as an analgesic to reduce perioperative opioid consumption and has also been shown to have antidepressant effects. Side effects of ketamine include dizziness, diplopia, nystagmus, and psychomimetic effects. It is unclear what clinical factors may be associated with ketamine-related adverse drug events (ADEs). Methods We performed a retrospective review of 95 patients who received sub-anesthetic ketamine infusions at our institution. Data examined associations between ketamine-related ADEs and various clinical characteristics including chronic pain, depression, or psychiatric disorder, patient physical characteristics, chronic opioid use, perioperative opioid use, dose and duration of ketamine infusions, pain scores, and perioperative medications such as serotonergic agents, central nervous system (CNS) depressants, and analgesics. Results Overall incidence of ketamine-related ADEs was 29.5% and the incidence of psychomimetic effects was 14.8%. We observed that patients with a history of depression have a lower incidence of ketamine-related ADEs compared to patients without a history of depression (10.3% vs 37.3%; p value = 0.007). Conclusion Patients with depression were found to have a statistically significant reduction in the incidence of ketamine-related ADEs. We found no statistically significant positive associations between ketamine-related ADEs and other clinical factors such as a history of chronic pain, psychiatric disease, patient physical characteristics, perioperative opioid use, dose of ketamine infusion, or co-administration of other CNS depressants.

This article presents three cases of cranial nerve palsy following shoulder surgery with general anesthesia in the beach chair position. All patients underwent preoperative ultrasound-guided interscalene nerve block. Two cases of postoperative hypoglossal and one case of combined hypoglossal and recurrent laryngeal nerve palsies (Tapia’s syndrome) were identified. Through this case series, we provide a literature review identifying postoperative cranial nerve palsies in addition to the discussion of possible etiologies. We suggest that intraoperative patient positioning and/or airway instrumentation is most likely causative. We conclude that the beach chair position is a risk factor for postoperative hypoglossal nerve palsy and Tapia’s syndrome.

Intraoperative Transesophageal Echocardiography (TEE) during orthotopic liver transplant (OLT) is used to gather real-time information on cardiovascular function and intravascular volume status. We report a case where nonstandard TEE views were used to inspect the hepatic vasculature after allograft implantation. A 29-year-old male with secondary biliary cirrhosis with a MELD score of 20 underwent OLT using a liver from a 21-year-old brain-dead donor. Postreperfusion TEE, using the modified hepatic vein views, confirmed the presence of an inferior vena cava (IVC) suprahepatic anastomotic stenosis and hepatic vein and IVC thrombus resulting in hepatic venous outflow obstruction, allograft congestion, and hemodynamic instability. These nonstandard TEE images established the extent of suprahepatic caval outflow obstruction, in which intraoperative ultrasound was unable to definitively demonstrate. This guided real-time surgical decision-making in the postimplantation phase of the operation—ultimately leading to hepatic vein and IVC thrombectomy and revision of suprahepatic caval anastomosis.

Background and Aims: There are limited data on the effect of ampule size on drug dosing. The objective of this study is to determine the effect of ampule size on perioperative opioid dosing and post-anesthesia care unit (PACU) outcomes. Material and Methods: This was a retrospective review of patients undergoing robotically assisted laparoscopic radical prostatectomy before and after a 5-ml fentanyl ampule was discontinued. The primary outcome was intraoperative opioid administration divided into fentanyl at induction of anesthesia, total fentanyl, and total opioid. Secondary outcomes observed in PACU included the opioid administered, visual analog scale (VAS) pain scores, postoperative nausea and vomiting, and length of stay in PACU. Results: A total of 100 patients (50 PRE and 50 POST) were included. In the intraoperative opioid administration, mean (SD) of fentanyl at induction was 117.0 (49.3) in PRE group and 85.0 (35.4) μg in POST group (P < 0.01). The total fentanyl requirement was 247.0 (31.0) in PRE group and 158.5 (85.1) μg in POST group (P < 0.01). The total opioid in intravenous morphine equivalents (IVME) was 34.1 (5.8) in PRE group and 23.2 (6.8) mg in POST group (P < 0.01). Among the secondary outcomes, mean (SD) of IVME of opioid was 7.7 (8.2) in PRE group and 9.9 (8.1) mg in POST group (P = 0.18). The VAS pain score on arrival was 0.7 (1.4) in PRE group and 3.8 (3.3) in POST group (P < 0.01). The cumulative VAS pain score was 2.3 (2.0) in PRE group and 3.3 (2.2) in POST group (P < 0.01). The length of stay was significantly more in POST group, 193.8 (75.8) minutes, as compared with PRE group, 138.6 (61.0) minutes (P < 0.01). Conclusions: A change in the ampule size significantly affected intraoperative dosing, PACU pain scores, and PACU length of stay in patients undergoing robotically assisted laparoscopic radical prostatectomy under general anesthesia. This was explained by clinician's desire to conserve the drug and avoid the complex process of narcotic waste disposal.

Background Previous studies have demonstrated improvements in efficiency when specific procedures are performed in a designated preoperative area prior to proceeding to the operating room. In this study the authors sought to evaluate if spinal anesthesia could be safely and efficiently administered prior to proceeding to the operating room when compared to general anesthesia and spinal anesthesia administered in the operating room. Methods The authors reviewed the electronic health record at a single institution between the years 2012 to 2018. Total joint arthroplasties by a single surgeon were identified and the specific time frames of interest were measured and compared between patients who received a spinal anesthetic in the preoperative area, patients who received a general anesthetic, and patients who received a spinal anesthetic in the operating room. These time frames of interest included: anesthesia induction time, operating room recovery time, post anesthesia recovery unit time, and operating room turnover time. The electronic medical record was also reviewed for spinal-related adverse events. Categorical variables were compared using the Fisher exact test and continuous variables were compared using equal-variance t-test and one-way ANOVA. Results The study cohort consisted of 246 patients (142 total hip arthroplasty and 104 total knee arthroplasty); 40.2% (99) of patients received a general anesthetic (GA), 52% (128) of patients received a preoperative spinal anesthetic (PSA), and 7.7% (19) of patients received an intraoperative spinal anesthetic (ISA). Preoperative spinal anesthetics demonstrated a shorter anesthesia induction time, shorter operating room recovery times, shorter PACU recovery times, and longer operating room turnover times when compared to general anesthesia and intraoperative spinals. There were no spinal-related adverse events. Conclusion The results of this retrospective cohort study demonstrate that administration of spinal anesthesia in the preoperative area is safe as compared with intra-operative spinal administration. Pre-operative spinal for total joint arthroplasty reduces time spent in the operating room and PACU when compared with general anesthesia and intraoperative spinal but it does not substantially affect overall perioperative efficiency.

Andrew W Gorlin,David M Rosenfeld,Jillian Maloney,Christopher S Wie,Johnathan McGarvey,Terrence L Trentman Department of Anesthesiology, Mayo Clinic Arizona, Phoenix, AZ, USA Abstract: The conversion of high-dose intravenous (IV) opioids to an equianalgesic epidural (EP) or intrathecal (IT) dose is a common clinical dilemma for which there is little evidence to guide practice. Expert opinion varies, though a 100 IV:10:EP:1 IT conversion ratio is commonly cited in the literature, especially for morphine. In this study, the authors surveyed 724 pain specialists to elucidate the ratios that respondents apply to convert high-dose IV morphine, hydromorphone, and fentanyl to both EP and IT routes. Eighty-three respondents completed the survey. Conversion ratios were calculated and entered into graphical scatter plots. The data suggest that there is wide variation in how pain specialists convert high-dose IV opioids to EP and IT routes. The 100 IV:10 EP:1 IT ratio was the most common answer of survey respondent, especially for morphine, though also for hydromorphone and fentanyl. Furthermore, more respondents applied a more aggressive conversion strategy for hydromorphone and fentanyl, likely reflecting less spinal selectivity of those opioids compared with morphine. The authors conclude that there is little consensus on this issue and suggest that in the absence of better data, a conservative approach to opioid conversion between IV and neuraxial routes is warranted. Keywords: intrathecal pump, epidural, cancer pain

Background: Minimally invasive repair of pectus excavatum (MIRPE) is now performed in adults. Managing adult patients’ pain postoperatively has been challenging due to increased chest wall rigidity and the pressure required for supporting the elevated sternum. The optimal pain management regimen has not been determined. We designed this prospective, randomized trial to compare postoperative pain management and outcomes between thoracic epidural analgesia (TEA) and bilateral subcutaneous infusion pump catheters (On-Q). Methods: Patients undergoing MIRPE (modified Nuss) underwent random assignment to TEA or On-Q group. Both groups received intravenous, patient-controlled opioid analgesia, with concomitant delivery of local anesthetic. Primary outcomes were length of stay (LOS), opioid use, and pain scores. Results: Of 85 randomly assigned patients, 68 completed the study [52 men, 76.5%; mean (range) age, 32.2 (20.0–58.0) years; Haller index, 5.9 (range, 3.0-26.7)]. The groups were equally matched for preoperative variables; however, the On-Q arm had more patients (60.3%). No significant differences were found between groups in mean daily pain scores (P=0.52), morphine-equivalent opioid usage (P=0.28), or hospital stay 3.5 vs . 3.3 days (TEA vs . On-Q; P=0.55). Thirteen patients randomized to TEA refused the epidural and withdrew from the study because they perceived greater benefit of the On-Q system. Conclusions: Postoperative pain management in adults after MIRPE can be difficult. Both continuous local anesthetic delivery by TEA and On-Q catheters with concomitant, intravenous, patient-controlled anesthesia maintained acceptable analgesia with a reasonable LOS. In our cohort, there was preference for the On-Q system for pain management.

Ketamine, an N-methyl-d-aspartate antagonist, blunts central pain sensitization at sub-anesthetic doses (0.3 mg/kg or less) and has been studied extensively as an adjunct for perioperative analgesia. At sub-anesthetic doses, ketamine has a minimal physiologic impact though it is associated with a low incidence of mild psychomimetic symptoms as well as nystagmus and double vision. Contraindications to its use do exist and due to ketamine's metabolism, caution should be exercised in patients with renal or hepatic dysfunction. Sub-anesthetic ketamine improves pain scores and reduces perioperative opioid consumption in a broad range of surgical procedures. In addition, there is evidence that ketamine may be useful in patients with opioid tolerance and for preventing chronic postsurgical pain.

Background. Utilization of intraoperative transesophageal echocardiography (TEE) during orthotopic liver transplantation (OLT) is expanding annually in high-volume transplant centers. During OLT intraoperative TEE is used to gather real-time information on cardiovascular function and intravascular volume status. Although standardized TEE views exist, there are nontraditional views described in the literature which have the potential to diagnose evolving pathology and define normal variants of hepatic vasculature. Methods. A literature review was completed utilizing the PubMed database for English-only, peer-reviewed publications discussing nontraditional use of intraoperative TEE during OLT and hepatic vascular-related surgeries from 2009 to 2019. Both case reports and review articles were considered. Results. The PubMed literature search offered 8 publications for analysis, including 7 case reports and 1 article review, revealing several nontraditional TEE views not included in a comprehensive transesophageal echocardiographic examination. These nontraditional views were generally obtained using modifications to the transgastric and bicaval views to visualize liver vasculature. We present the various techniques for obtaining these views from the 8 articles identified. Conclusions. At high-volume transplant centers, TEE use during OLT is increasing. Intraoperative TEE is a valuable tool to assess hepatic vascular structures critical to allograft/organ function without interruption of the surgical procedure. Nontraditional use of TEE to diagnose intraoperative noncardiac pathology in OLT appears underutilized and underreported. The modified hepatic and modified transgastric views we describe can be used to evaluate hepatic vasculature, influence surgical decision-making and ultimately improve patient care.

Organ shortage is a major cause of delayed liver transplantation and increased waitlist time. The level of donor steatosis is a significant determinant in organ selection. Scarcity of organs has led some programs to expand their acceptable criteria for the percentage of steatosis. We report two cases of liver transplantation of steatotic donor organs that resulted in mortality within hours from transplantation. Postmortem analysis showed evidence of diffuse pulmonary fat microemboli likely originating from the donor organ, with marked preservation reperfusion injury. The mechanism of diffuse fat microemboli in this setting and possible relationship to other perioperative syndromes (transfusion-related lung injury, acute kidney injury, and postreperfusion syndrome) is discussed.

We review contemporary coagulation management for patients undergoing liver transplantation. A better understanding of the complex physiologic changes that occur in patients with end-stage liver disease has resulted in significant advances in anesthetic and coagulation management. A group of internationally recognized experts have critically evaluated current approaches for coagulopathy detection and management. Strategies for blood component and factor replacement have been evaluated and recommended therapies proposed. Pharmacologic treatment and prevention of coagulopathy, management of patients receiving antiplatelet medications, and the role of transesophageal echocardiography for early detection and management of thromboses are presented.

Introduction Sexual dysfunction is a well-known side effect of antidepressants. Painful ejaculation is a rare side effect that has been reported with the use of some psychiatric drugs such as triclyclic antidepressants. Cyclobenzaprine is a muscle relaxant that is structurally similar to tricyclic antidepressants. It is the most commonly prescribed muscle relaxant in the United States and accounts for 18% of all prescriptions written for chronic back pain. Methods A 55-year-old man was referred to our pain medicine clinic for evaluation and treatment of pain with ejaculation. Main outcome Measure The main outcome measure was to review the current published literature and case reports on painful ejaculation from medication use, in particular tricyclic antidepressants. Results After discontinuation of cyclobenzaprine, our patient's sexual dysfunction resolved. This result was consistent with the literature reviewed on the topic. Conclusion Painful ejaculation is likely an underreported side effect of tricyclic antidepressants and cyclobenzaprine use. Fortunately, these symptoms are reversible and discontinuation of these medications is typically an effective cure.

This randomised, double-blind, placebo-controlled study compared the effect of perineural with intravenous dexamethasone, both administered concomitantly with interscalene brachial plexus block for shoulder surgery. Patients received 8 mg dexamethasone mixed with ropivacaine in the block injection (n = 42), 8 mg dexamethasone intravenously at the time of the block (n = 37), or intravenous saline (n = 41) at the time of the block. Perineural and intravenous dexamethasone resulted in prolonged mean (SD) duration of block to 16.9 (5.2) h and 18.2 (6.4) h, respectively, compared with 13.8 (3.8) h for saline (p = 0.001). Mean (SD) opioid consumption (morphine equivalents) during the first 24 h after postanaesthesia recovery arrival was 12.2 (9.3) mg in the perineural dexamethasone, 17.1 (15.9) mg in the intravenous dexamethasone and 24.1 (14.3) mg in the saline groups (p = 0.001). Dexamethasone via either route reduced anti-emetic use (p = 0.046). There was no effect on patient satisfaction. These results suggest that both perineural and intravenous dexamethasone are useful adjuncts to ropivacaine interscalene block, with the intravenous route preferred as this avoids the possibility of neural toxicity of dexamethasone.

Background: Millions of patients suffer from medically refractory and disabling primary headache disorders. This problem has led to a search for new and innovative treatment modalities, including neuromodulation of the occipital nerves. Objectives: The primary aim of this study is to describe an implantation technique for the Bion® microstimulator and document stimulation parameters and stimulation maps after Bion placement adjacent to the greater occipital nerve. The secondary aim is to document outcome measures one year post-implant. Design: Prospective, observational feasibility study. Methods: Nine patients with medically refractory primary headache disorders participated in this study. Approximately 6 months after Bion insertion, stimulation parameters and maps were documented for all patients. At one year, outcome measures were collected including the Migraine Disability Assessment Score. Results: At 6 months, the mean perception threshold was 0.47 mA, while the mean discomfort threshold was 6.8 mA (stimulation range 0.47 – 6.8 mA). The mean paresthesia threshold was 1.64 mA and the mean usage range was 16.0. There were no major complications reported such as device migration, infection, or erosion. One patient stopped using her Bion before the 12-month follow-up visit. At one year, 7 of the 8 patients were judged as having obtained fair or better results in terms of reduction of disability; 5 patients had greater than a 90% reduction in disability. Limitations: Small, heterogeneous patient population without control group. Not blinded or randomized. Conclusion: The Bion can be successfully inserted adjacent to the greater occipital nerve in an effort to treat refractory primary headache disorders. This microstimulator may provide effective occipital stimulation and headache control while minimizing the risks associated with percutaneous or paddle leads implanted subcutaneously in the occipital region. Key words: Chronic headache, migraine, cluster headache, peripheral nerve stimulation

Background Facial pain can be a management challenge. Peripheral nerve/field stimulation may be an effective option for refractory cases, but direct muscle stimulation with facial twitching may result. Botulinum toxin injections have been used for blepharospasm and may be effective when facial stimulation results in unacceptable facial muscle twitching due to peripheral stimulation. Case presentation A 53-year old female suffered with chronic, refractory facial pain and migraines. Her facial pain began after a root canal of a left upper molar. She was trialed and then permanently implanted with a 1 × 8 sub-compact percutaneous stimulator lead, resulting in improved pain control and reduced medication use. However, she experienced blepharospasm whenever the amplitude was above 2.75 A. Therefore, she was treated with botulinum toxin injections into her bilateral cheek, face, temple and occiput. This treatment provided excellent relief of the facial spasms, allowing her to use her stimulator at high amplitudes, and thereby maximizing her pain relief. She received two subsequent treatments of botulinum toxin injections at 5-month intervals with similar results. Conclusion Peripheral nerve/field stimulation is being used for headaches and facial pain. An undesirable side effect of this emerging therapy is direct muscle stimulation. Botulinum toxin injections may be an effective treatment modality when stimulation techniques provide pain relief but also causes muscle twitching.

Objective: Fospropofol disodium (Lusedra®) is a pro-drug propofol for Monitored Anesthesia Care. The FDA-approved dose regimen is minimally effective with a slow onset often requiring supplemental doses at 4 minutes to achieve adequate sedation and frequently requires early re-dosing. This study was designed to assess if a larger initial bolus dose of 10 mg/kg could achieve successful sedation without supplemental doses and without an increase in sedation-related adverse events. Methods: An IRB-approved trial enrolled 12 adults undergoing elective orthopedic surgery with regional block. After IV fentanyl 50-75 micrograms, patients were randomly assigned into three IV bolus groups: fospropofol 6.5 mg/kg, fospropofol 10 mg/kg, or placebo with midazolam for rescue sedation if needed. Following the initial bolus, the level of sedation was measured, and, if adequate, the block initiated or additional IV sedation injected before proceeding with the block. Results: 100% of the 10 mg/kg fospropofol group achieved appropriate sedation in less than 4 minutes compared to 50% of the 6.5 mg/kg group (P=0.048) and 40% of the fentanyl only participants with average times to sedation of 2.0 ± 0.0 minutes, 5.0 ± 4.0 minutes, and 7.0 ± 6.0 minutes, respectively. All of the 10 mg/kg group experienced deep sedation (MOAA/S 1-2), 60% experienced paresthesia or pruritus on bolus injection, 40% experienced delayed recovery from sedation, and 20% (1 of 5 patients) experienced a short period of apnea without hypoxemia. Sedation with midazolam produced delayed recovery in 40% of patients and 20% experienced deep sedation (MOAA/S 1-2). Conclusion: 10 mg/kg bolus-dose fospropofol was 100% successful in producing sedation in less than 4 minutes, but was accompanied by deep sedation (p+0.048) and delayed recovery from sedation and more frequent apnea that make this dose unsuitable for procedures requiring short or minimal-to-moderate sedation. Further randomized trials with adequate power are required including consideration of an 8 mg/kg dose of fospropofol for MAC sedation procedures.

Purpose: To compare the post operative pain control of four distinct management strategies in adult live donor hepatectomy. Methods: Sixty-two ASA physical status I and II patients undergoing live donor hepatic resection from 2001 to 2008 were retrospectively organized into four groups for post-operative pain control. Group A received epidural catheter, Group B received PCA, Group C received intraoperative dexmedetomidine and PCA, and Group D received perioperative gabapentin, intraoperative dexmedetomidine, and PCA. Four day postoperative visual analog pain scores (VAS), intravenous morphine equivalent use, duration of hospitalization, and time until return of bowel function was measured. Results: Mean visual analog pain score for a cumulative four day postoperative interval demonstrated 2.2 (± 0.73) for epidural catheter, 3.4 (± 1.13) for patient controlled analgesia (PCA), 3.0 (± 1.42) for intraoperative dexmedetomidine infusion plus PCA, and 2.3 (± 1.09) for perioperative gabapentin, intraoperative dexmedetomidine, combined with PCA. These results achieved statistical significance with p = 0.0443. Total intravenous morphine equivalent use was similar between the three non-epidural groups. There was no difference in length of hospitalization or time until return of bowel function amongst the four groups. Conclusions: Both epidural infusion and a three drug regimen of perioperative gabapentin, intraoperative dexmedetomidine, and PCA produced superior postoperative pain control compared with PCA alone or a combination of PCA and dexmedetomidine. The three drug regimen represents a preferred strategy as it provides optimal pain control without the theoretic risk of epidural hematoma in patients with a predictable postoperative coagulopathy. This pilot study serves as a template for future prospective examination of this three drug regimen versus epidural in major non-hepatic open abdominal surgery where post operative coagulopathy is less of a concern.

Millions of patients suffer from medically refractory and disabling primary headache disorders. This problem has led to a search for new and innovative treatment modalities, including neuromodulation of the occipital nerves.The primary aim of this study is to describe an implantation technique for the Bion microstimulator and document stimulation parameters and stimulation maps after Bion placement adjacent to the greater occipital nerve. The secondary aim is to document outcome measures one year post-implant.Prospective, observational feasibility study.Nine patients with medically refractory primary headache disorders participated in this study. Approximately 6 months after Bion insertion, stimulation parameters and maps were documented for all patients. At one year, outcome measures were collected including the Migraine Disability Assessment Score.At 6 months, the mean perception threshold was 0.47 mA, while the mean discomfort threshold was 6.8 mA (stimulation range 0.47-6.8 mA). The mean paresthesia threshold was 1.64 mA and the mean usage range was 16.0. There were no major complications reported such as device migration, infection, or erosion. One patient stopped using her Bion before the 12-month follow-up visit. At one year, 7 of the 8 patients were judged as having obtained fair or better results in terms of reduction of disability; 5 patients had greater than a 90% reduction in disability.Small, heterogeneous patient population without control group. Not blinded or randomized.The Bion can be successfully inserted adjacent to the greater occipital nerve in an effort to treat refractory primary headache disorders. This microstimulator may provide effective occipital stimulation and headache control while minimizing the risks associated with percutaneous or paddle leads implanted subcutaneously in the occipital region.

In most cases of post-dural puncture headache, the positional symptoms will resolve spontaneously within 2 weeks. Conservative therapies include oral analgesics and hydration, bed rest, and abdominal binders. For refractory cases, an autologous epidural blood patch remains the treatment of choice. However, in certain cases the use of autologous blood for the blood patch may place the patient at risk for infectious or malignant contamination of the central nervous system. Coccidioidomycosis results from inhalation of the arthroconidia (spore) stage of the fungal lifecycle. The most common manifestation of coccidioidomycosis is acute pulmonary symptoms, while the most feared complication is meningitis. Immunocompromised patients are at increased risk of fungemia; therefore, introduction of fungal elements into the central nervous system can occur if autologous blood is used for an epidural blood patch. We report a case of persistent dural-puncture headache in the setting of disseminated coccidioidomycosis. An autologous blood epidural blood patch was considered but deferred due to risk of coccidioidomycosis meningitis. Other epidural space interventions such as fibrin glue injection or saline infusions were judged to be too imprecise or ineffective. The patient was successfully treated with allogeneic blood donated by his wife, but only after testing of her blood as is required for any directed blood donation. Allogeneic epidural blood patches are an option for refractory dural puncture headaches when autologous blood may cause meningitis or malignant seeding of the central nervous system.