Reduced Pain and Opioid Use in the Early Postoperative Period in Patients Undergoing a Frontotemporal Craniotomy under Regional vs General Anesthesia.

INTRODUCTION: This study compares the postsurgical course of frontotemporal craniotomies conducted "awake" under regional anesthesia (RA) versus "asleep" under general anesthesia (GA) to investigate postoperative recovery, pain, opioid use, and anesthesia-related side effects. METHODS: We retrospectively reviewed craniotomies for supratentorial, intra-axial tumors with frontotemporal exposure. Chronic opioid use and emergent cases were excluded. Primary outcomes included pain scores on a 0-10 numerical rating scale, opioid use as oral morphine milligram equivalence, first time to opioid use, nausea, and sedation on the Richmond Agitation and Sedation Scale (RASS). Secondary outcomes included postoperative seizures, Karnofsky Performance Scale (KPS) status, and hospital length of stay (LOS). RESULTS: A total of 91 patients met inclusion criteria: 56 underwent a craniotomy under RA versus 35 under GA. Demographics and operative characteristics were similar between cohorts. A significant reduction in both postoperative pain and opioid use was observed among RA versus GA (first postoperative pain score 2 vs. 5, P < 0.01; postoperative day [POD] 0 median pain score 2.5 vs. 4, P < 0.01; POD 0 mean opioid in mg 14.49 vs. 24.43, P < 0.01). The time until patients requested opioids for pain after surgery was prolonged for RA versus GA [mean 7.23 vs. 3.42 hours, P < 0.01). Somnolence (RASS < 0) on POD 0 was significantly reduced among RA versus GA, with 23% versus 43%. Both cohorts had equivocal postsurgical outcomes such as seizures, KPS, and hospital LOS. CONCLUSIONS: Frontotemporal craniotomy under RA during awake craniotomies provides better pain control, a reduction in opioid use, and less somnolence in the early postoperative period.

Awake Craniotomy in a Patient with Previously Diagnosed Post-Traumatic Stress Disorder.

BACKGROUND: Awake craniotomy (AC) with brain mapping has been successfully used for the resection of lesions located in or near eloquent areas of the brain. The selection process includes a thorough presurgical evaluation to determine candidates suitable for the procedure. Psychiatric disorders including post-traumatic stress disorder (PTSD) are considered potential contraindications for this type of surgery because these patients may be less cooperative to tolerate AC. Here we present the management of a patient with PTSD who underwent an AC using a multidisciplinary team for removal of a dominant hemisphere low-grade insular glioma with speech, motor, and cognitive mapping. CASE DESCRIPTION: A 34-year-old right-handed male military veteran with a previous history of PTSD was scheduled for a left AC for resection of a low-grade insular glioma. He underwent preoperative neurocognitive assessment with a neuropsychologist and clinic visit with a neurosurgeon to characterize his PTSD and potential triggers, explain the procedure in a stepwise fashion, and address any concerns. The intraoperative environment was modified to minimize triggering stimuli, and an asleep-awake-asleep anesthetic protocol was followed. The patient tolerated the procedure well without any postoperative neurologic deficits including cognitive deficits. At 1-month follow-up, he denied any worsening of his PTSD symptoms and recalls the AC as a positive experience. CONCLUSIONS: With a multidisciplinary team, adequate preoperative education, detailed clinical interview to identify triggers, and a controlled intraoperative environment, awake surgery can be carried out safely in a patient with PTSD.

Sugammadex: a novel approach to reversal of neuromuscular blockade.

Sugammadex is the first in a new class of medications termed selective relaxant binding agents. This medication acts to encapsulate free circulating steroidal nondepolarizing neuromuscular blocking agents. The encapsulation of neuromuscular agents effectively decreases the amount of neuromuscular blocker interacting at the neuromuscular receptor. This binding has a very high association rate, rendering the incidence of residual block extremely low, while avoiding the side effects associated with traditional reversal agents. Currently approved for clinical use in over 50 countries, sugammadex was not approved by the US FDA in 2008 due to concerns over potential hypersensitivity reactions. It is hoped that further study and clinical experience will help to better define the risk associated with sugammadex and eventually lead to the approval of this novel medication in the USA.

Transesophageal echocardiography for detection of propagating, massive emboli during prosthetic hip fracture surgery.

Fat embolus has been known to occur during major orthopedic surgery. In many cases, fat embolus syndrome is a postoperative complication of long bone orthopedic surgery, particularly femoral fractures occurring after trauma. Changes in intraoperative cardiopulmonary function have been reported in a subset of these patients, and they are associated with the degree of embolization occurring with manipulation or cementing of prostheses in the fractured femur. Intraoperative cardiovascular collapse has been reported, and this cardiac event is temporally associated with intramedullary manipulations such as reaming or cementing. We present a rare case of fatal intraoperative fat embolization diagnosed with trans-esophageal echocardiography.

Fat emboli in total knee arthroplasty: a prospective randomized study of computer-assisted navigation vs standard surgical technique.

A prospective exploratory study of fat emboli in patients undergoing total knee arthroplasty was performed in patients randomly assigned to surgery with computer-assisted navigation or standard technique. Transesophageal echocardiography of the right atrium was recorded for 5 consecutive 1-minute intervals after tourniquet deflation. Emboli were graded on a scale of 0 to 3 based on embolism size, amount of atrium filled, and duration of embolic shower, creating an overall score of 0 to 9. The mean (SD, range) of the 5 overall scores for each total knee arthroplasty was 6.00 (0.76, 4.6-7.4) for computer-assisted navigation (22 patients) and 6.42 (0.97, 4.6-7.9) for standard technique (22 patients) (P=.14), with a 95% confidence interval for the difference of -0.11 to 0.95. We conclude that any difference in extent of emboli between the 2 surgical techniques is unlikely to be of clinical significance.

Cerebral physiology of cardiac surgical patients treated with the perfluorocarbon emulsion, AF0144.

BACKGROUND: Perfluorooctyl bromide is a biologically inert compound with short biologic retention and high oxygen solubility. The purpose of this study was to assess the effect of the perfluorocarbon emulsion, AF0144 (Perflubron, Alliance Pharmaceutical Corp, San Diego, CA), used in conjunction with acute normovolemic hemodilution on cerebral blood flow and cerebral emboli measurements during coronary artery bypass grafting with cardiopulmonary bypass. METHODS: Thirty-six adult cardiac surgical patients were enrolled in a single-institution, randomized, controlled, single-blind dose escalation trial. Autologous whole blood was harvested from each patient to target an on-bypass hematocrit of 20% to 22%. Placebo, low dose (1.8 g/kg) or high dose (2.7 g/kg) AF0144 was administered. Transcranial Doppler ultrasonography was used to quantitate cerebral emboli and xenon-133 clearance was used to measure cerebral blood flow. RESULTS: Cerebral blood flow was increased in both AF0144-treated groups compared with placebo (p = 0.006, low dose vs control; p = 0.036, high dose vs control). Numbers of cerebral emboli were greater in the high-dose AF0144-treated group versus control during the time periods from aortic cannulation through aortic cross-clamp placement (p = 0.026) and from aortic cross-clamp placement through cross-clamp removal (p = 0.008). CONCLUSIONS: The perfluorocarbon emulsion, AF0144, increased cerebral blood flow during cardiopulmonary bypass. In addition, total cerebral emboli load during bypass was greater in patients receiving high-dose AF0144.

Effects of positive-pressure ventilation, pericardial effusion, and cardiac tamponade on respiratory variation in transmitral flow velocities.

OBJECTIVE: To determine the effects of positive-pressure ventilation and experimentally induced pericardial effusion and tamponade on transmitral flow velocities in dogs. DESIGN: Descriptive. SETTING: University laboratory. PARTICIPANTS: Eleven tracheally intubated and mechanically ventilated dogs. INTERVENTIONS: Experimental pericardial effusion and cardiac tamponade were created by pericardial injection of warm saline. MEASUREMENTS AND MAIN RESULTS: Hemodynamic parameters and pericardial pressures were monitored in the 11 dogs. Pulsed-wave Doppler tracings of mitral valve flow were obtained at the leaflet tips along with hemodynamic measurements at 4 stages: control, effusion (no decrease in mean arterial pressure), tamponade (>or=40% decrease in mean arterial pressure), and tamponade relief (after evacuation of pericardial fluid). Maximal variation (36%) in transmitral flow velocity over the respiratory cycle during positive-pressure ventilation was seen in the control stage. In the effusion and tamponade stages, variation in transmitral flow velocity decreased progressively to 29% (p = 0.1804, not significant) and 16% (p < 0.0001), respectively. CONCLUSION: Intrathoracic pressure and lung volume changes caused by positive-pressure ventilation influence transmitral flow velocity patterns. Respiratory variation in transvalvular flow is pronounced during standard positive-pressure mechanical ventilation, decreases in the presence of pericardial effusion, and becomes almost nonexistent when cardiac tamponade is present. These findings show that the echocardiographic criteria used to diagnose cardiac tamponade based on mitral valve inflow patterns are different during positive-pressure ventilation from spontaneously breathing subjects.

Perflubron emulsion (AF0144) augments harvesting of autologous blood: a phase II study in cardiac surgery.

OBJECTIVE: To assess tolerance and preliminary efficacy of a perfluorocarbon emulsion (AF0144) used with acute normovolemic hemodilution to reduce allogeneic blood transfusion for patients undergoing coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB). DESIGN: Controlled, single-blind, parallel-group phase II dose escalation trial. SETTING: Single-institution university medical center. PARTICIPANTS: Adult patients undergoing elective CABG surgery (n = 36). INTERVENTIONS: A calculated volume of autologous whole blood was harvested for each patient with a target on-bypass hematocrit of 20% to 22%. Placebo, low-dose (1.8 g/kg) AF0144, or high-dose (2.7 g/kg) AF0144 was infused. During CPB, blood was transfused at protocol-defined triggers (hematocrit <15%, PvO(2) <30 mmHg, SvO(2) <60%). After CPB, all autologous whole blood was reinfused. Allogeneic red blood cells were transfused if a trigger was reached. MEASUREMENTS AND MAIN RESULTS: Safety assessments (vital signs, hematology, blood chemistry, coagulation, and adverse events) were monitored through postoperative day 21. Efficacy endpoints included percentage of patients reaching a transfusion trigger and number of allogeneic units of red blood cells transfused. During CPB, <25% of subjects reached a transfusion trigger. During hospitalization, significantly fewer (p < 0.01) high-dose subjects (33%) reached a trigger than did control patients (91%). Allogeneic red blood cell transfusion did not differ significantly among groups. Safety assessments indicated AF0144 was well tolerated. CONCLUSION: The data suggest that AF0144 when used with acute normovolemic hemodilution is well tolerated and may be effective when used to enhance oxygen delivery for patients undergoing CABG surgery. Confirmation of safety and efficacy in a larger phase III clinical trial is warranted.

Esmolol improves left ventricular function via enhanced beta-adrenergic receptor signaling in a canine model of coronary revascularization.

BACKGROUND: Recent American Heart Association guidelines highlight the paucity of data on effectiveness and/or mechanisms underlying use of beta-adrenergic receptor (beta AR) antagonists after acute coronary syndromes in patients subsequently undergoing revascularization. It is important to assess whether beta AR antagonists might protect the heart and improve ventricular function in this scenario. The authors therefore used esmolol (an ultra-short-acting beta AR antagonist) to determine whether beta AR antagonist treatment improves left ventricular function in a canine model of acute reversible coronary ischemia followed by coronary reperfusion during cardiopulmonary bypass (CPB). The authors also tested whether the mechanism includes preserved beta AR signaling. METHODS: Dogs were randomized to either esmolol or saline infusions administered during CPB (n = 29). Pre-CPB and end-CPB transmyocardial left ventricular biopsies were obtained; plasma catecholamine concentrations, myocardial beta AR density, and adenylyl cyclase activity were measured. In addition, left ventricular systolic shortening and postsystolic shortening were determined immediately prior to each biopsy. RESULTS: While beta AR density remained unchanged in each group, isoproterenol-stimulated adenylyl cyclase activity decreased 26 +/- 6% in the control group but increased 38 +/- 10% in the esmolol group (pre-CPB to end-CPB, mean +/- SD, P = 0.0001). Left ventricular systolic shortening improved in both groups after release of coronary (LAD) ligature; however, the esmolol group increased to 72 +/- 23% of pre-CPB values compared to 48 +/- 12% for the control group (P = 0.0008). CONCLUSIONS: These data provide prospective evidence that esmolol administration results in improved myocardial function. Furthermore, the mechanism appears to involve enhanced myocardial beta AR signaling.