Jaime Ortiz

A prospective, randomized, controlled trial comparing ultrasound versus nerve stimulator guidance for interscalene block for ambulatory shoulder surgery for postoperative neurological symptoms.

BACKGROUND: Visualization with ultrasound during regional anesthesia may reduce the risk of intraneural injection and subsequent neurological symptoms but has not been formally assessed. Thus, we performed this randomized clinical trial comparing ultrasound versus nerve stimulator-guided interscalene blocks for shoulder arthroscopy to determine whether ultrasound could reduce the incidence of postoperative neurological symptoms. METHODS: Two hundred thirty patients were randomized to a standardized interscalene block with either ultrasound or nerve stimulator with a 5 cm, 22 g Stimuplex® insulated needle with 1.5% mepivacaine with 1:300,000 epinephrine and NaCO3 (1 meq/10 mL). A standardized neurological assessment tool (questionnaire and physical examination) designed by a neurologist was administered before surgery (both components), at approximately 1 wk after surgery (questionnaire), and at approximately 4–6 weeks after surgery (both components). Diagnosis of postoperative neurological symptoms was determined by a neurologist blinded to block technique. RESULTS: Two hundred nineteen patients were evaluated. Use of ultrasound decreased the number of needle passes for block performance (1 vs 3, median, P < 0.001), enhanced motor block at the 5-min assessment (P = 0.04) but did not decrease block performance time (5 min for both). No patient required conversion to general anesthesia for failed block, and patient satisfaction was similar in both groups (96% nerve stimulator and 92% ultrasound). The incidence of postoperative neurological symptoms was similar at 1 wk follow-up with 11% (95% CI of 5%–17%) for nerve stimulator and 8% (95% CI of 3%–13%) for ultrasound and was similar at late follow-up with 7% (95% CI of 3%–12%) for nerve stimulator and 6% (95% CI of 2%–11%) for ultrasound. The severity of postoperative neurological symptoms was similar between groups with a median patient rating of moderate. Symptoms were primarily sensory and consisted of pain, tingling, or paresthesias. CONCLUSIONS: Ultrasound reduced the number of needle passes needed to perform interscalene block and enhanced motor block at the 5 min assessment; however, we did not observe significant differences in block failures, patient satisfaction or incidence, and severity of postoperative neurological symptoms.

Bilateral Transversus Abdominis Plane Block Does Not Decrease Postoperative Pain After Laparoscopic Cholecystectomy When Compared With Local Anesthetic Infiltration of Trocar Insertion Sites

Background and Objectives Transversus abdominis plane (TAP) block has been shown to reduce pain and analgesic requirements after abdominal surgery. Our hypothesis was that bilateral TAP blocks decrease pain after laparoscopic cholecystectomy when compared with local anesthetic infiltration of trocar insertion sites. Methods Eighty patients undergoing laparoscopic cholecystectomy were randomized to receive either bilateral TAP blocks or local anesthetic infiltration of trocar insertion sites with ropivacaine 0.5%. Postoperative pain scores and analgesic use for the first 24 hrs were recorded. Results Eighty patients were enrolled in the study. After exclusions, data were analyzed on 39 patients in group T (bilateral TAP block) and 35 patients in group I (infiltration). There was no statistically significant difference in pain scores on the numeric analog scale (0–10) between the groups at 4 hrs after surgery (P = 0.18) or during the 24 hrs after surgery (P = 0.23). The time interval from anesthesia start to surgery start was greater in group T than group I (48 vs 35 mins, P < 0.001). There was no significant difference found in analgesic use during the first 24 hrs after surgery. Conclusions Bilateral ultrasound-guided TAP block is equivalent to local anesthetic infiltration of trocar insertion sites for overall postoperative pain in a heterogeneous group of patients undergoing laparoscopic cholecystectomy.

Additives to local anesthetics for peripheral nerve blocks: Evidence, limitations, and recommendations.

PURPOSE The therapeutic rationale, clinical effectiveness, and potential adverse effects of medications used in combination with local anesthetics for peripheral nerve block therapy are reviewed. SUMMARY A wide range of agents have been tested as adjuncts to peripheral nerve blocks, which are commonly performed for regional anesthesia during or after hand or arm surgery, neck or spine surgery, and other procedures. Studies to determine the comparative merits of nerve block adjuncts are complicated by the wide variety of coadministered local anesthetics and sites of administration and by the heterogeneity of primary endpoints. Sodium bicarbonate has been shown to speed the onset of mepivacaine nerve blocks but delay the onset of others. Epinephrine has been shown to prolong sensory nerve blockade and delay systemic uptake of local anesthetics, thus reducing the risk of anesthetic toxicity. Tramadol, buprenorphine, dexamethasone, and clonidine appear to be effective additives in some situations. Midazolam, magnesium, dexmedetomidine, and ketamine cannot be routinely recommended as nerve block additives due to a dearth of supportive data, modest efficacy, and (in the case of ketamine) significant adverse effects. Recent studies suggest that administering additives intravenously or intramuscularly can provide many of the benefits of perineural administration while reducing the potential for neurotoxicity, contamination, and other hazards. CONCLUSION Some additives to local anesthetics can hasten the onset of nerve block, prolong block duration, or reduce toxicity. On the other hand, poorly selected or unnecessary additives may not have the desired effect and may even expose patients to unnecessary risks.

The Emerging Use of Ketamine for Anesthesia and Sedation in Traumatic Brain Injuries

Traditionally, the use of ketamine for patients with traumatic brain injuries is contraindicated due to the concern of increasing intracranial pressure (ICP). These concerns, however, originated from early studies and case reports that were inadequately controlled and designed. Recently, the concern of using ketamine in these patients has been challenged by a number of published studies demonstrating that the use of ketamine was safe in these patients. This article reviews the current literature in regards to using ketamine in patients with traumatic brain injuries in different clinical settings associated with anesthesia, as well as reviews the potential mechanisms underlying the neuroprotective effects of ketamine. Studies examining the use of ketamine for induction, maintenance, and sedation in patients with TBI have had promising results. The use of ketamine in a controlled ventilation setting and in combination with other sedative agents has demonstrated no increase in ICP. The role of ketamine as a neuroprotective agent in humans remains inconclusive and adequately powered; randomized controlled trials performed in patients undergoing surgery for traumatic brain injury are necessary.

Randomized, controlled trial comparing the effects of anesthesia with propofol, isoflurane, desflurane and sevoflurane on pain after laparoscopic cholecystectomy

BACKGROUND Pain is the primary complaint and the main reason for prolonged recovery after laparoscopic cholecystectomy. The authors hypothesized that patients undergoing laparoscopic cholecystectomy will have less pain four hours after surgery when receiving maintenance of anesthesia with propofol when compared to isoflurane, desflurane, or sevoflurane. METHODS In this prospective, randomized trial, 80 patients scheduled for laparoscopic cholecystectomy were assigned to propofol, isoflurane, desflurane, or sevoflurane for the maintenance of anesthesia. Our primary outcome was pain measured on the numeric analog scale four hours after surgery. We also recorded intraoperative use of opioids as well as analgesic consumption during the first 24h after surgery. RESULTS There was no statistically significant difference in pain scores four hours after surgery (p=0.72). There were also no statistically significant differences in pain scores between treatment groups during the 24h after surgery (p=0.45). Intraoperative use of fentanyl and morphine did not vary significantly among the groups (p=0.21 and 0.24, respectively). There were no differences in total morphine and hydrocodone/APAP use during the first 24h (p=0.61 and 0.53, respectively). CONCLUSION Patients receiving maintenance of general anesthesia with propofol do not have less pain after laparoscopic cholecystectomy when compared to isoflurane, desflurane, or sevoflurane.

Neurocognitive effects following an overnight call shift on faculty anesthesiologists

The impact of sleep deprivation on neurocognitive performance is a significant concern to both the health of patients and to the physicians caring for them, as demonstrated by the Accreditation Council for Graduate Medical Education enforced resident work hours. This study examined the effects of an overnight call at a level 1 trauma hospital on neurocognitive performance of faculty anesthesiologists.

Multilevel continuous intercostal nerve block catheter: a viable alternative to thoracic epidural for multiple rib fractures?

In Reply: Drs. Slater and Lerner have reemphasized a critical point in our published case scenario1: Standard coagulation tests are inadequate in assessing adequacy of platelet function for epidural catheterization. Therefore, we recommended in our algorithm presented in figure 4 of our original report1 to use whole blood multiple electrode impedance aggregometry (Multiplate®; Roche Diagnostics, Mannheim, Germany) or whole blood turbidimetric aggregometry (VerifyNow®; Accumetrics, San Diego, CA) to support decision making in patients with antiplatelet therapy.1 Multiple electrode impedance aggregometry and VerifyNow® have been used to assess the efficacy of antiplatelet drugs and the dynamics of platelet function recovery after clopidogrel treatment—also under the scenario “risk–benefit analysis of neuraxial blockade.”2–7 Multiple electrode impedance aggregometry is as sensitive as light transmission aggregometry (Born aggregometry—the definitive standard of platelet function analysis) to detect platelet dysfunction,8,9 predict stent thrombosis and bleeding rates after coronary interventions,2,10 and can be used as a guide to support treatment of hemorrhagic patients undergoing cardiac surgery.11,12 Please note that the value of thromboelastography or thromboelastometry in our case scenario relates to detection of trauma-induced coagulopathy with reduced clot firmness13 and hypercoagulability due to an acute phase reaction with high plasma fibrinogen concentrations, which we know Multilevel Continuous Intercostal Nerve Block Catheter: A Viable Alternative to Thoracic Epidural for Multiple Rib Fractures?

Management of abdominal compartment syndrome after transurethral resection of the prostate

Acute abdominal compartment syndrome is most commonly associated with blunt abdominal trauma, although it has been seen after ruptured abdominal aortic aneurysm, liver transplantation, pancreatitis, and massive volume resuscitation. Acute abdominal compartment syndrome develops once the intra-abdominal pressure increases to 20-25 mmHg and is characterized by an increase in airway pressures, inadequate ventilation and oxygenation, altered renal function, and hemodynamic instability. This case report details the development of acute abdominal compartment syndrome during transurethral resection of the prostate with extra- and intraperitoneal bladder rupture under general anesthesia. The first signs of acute abdominal compartment syndrome in this patient were high peak airway pressures and difficulty delivering tidal volumes. Management of the compartment syndrome included re-intubation, emergent exploratory laparotomy, and drainage of irrigation fluid. Difficulty with ventilation should alert the anesthesiologist to consider abdominal compartment syndrome high in the list of differential diagnoses during any endoscopic bladder or bowel case.

Analgesic Benefits of Ultrasound-Guided Thoraco-Abdominal Wall Peripheral Nerve Blocks

Received: August 05, 2016 Revised: November 04, 2016 Accepted: November 16, 2016 Abstract: Background and Objectives: Peripheral nerve blocks have been associated with decreased opiate consumption along with decreased associated side effects, improved pain scores, improved patient satisfaction scores, and decreased hospital length of stay. The aim of this review is to describe the use of ultrasound-guided thoraco-abdominal wall peripheral nerve blocks for perioperative analgesia.

Anesthetic management of a large mediastinal mass for tracheal stent placement.

The anesthetic management of patients with large mediastinal masses can be complicated due to the pressure effects of the mass on the airway or major vessels. We present the successful anesthetic management of a 64-year-old female with a large mediastinal mass that encroached on the great vessels and compressed the trachea. A tracheal stent was placed to relieve the tracheal compression under general anesthesia. Spontaneous ventilation was maintained during the perioperative period with the use of a classic laryngeal mask airway. We discuss the utility of laryngeal mask airway for anesthetic management of tracheal stenting in patients with mediastinal masses.