Extracorporeal Membrane Oxygenation: The New Jack-of-All-Trades?

The role of extracorporeal membrane oxygenation in the adult patient population still is evolving. Technologic advancements have improved the ability to provide extracorporeal life support. The miniaturization and durability of these systems have made extracorporeal membrane oxygenation more convenient and mobile than ever. Because of these improvements, its use has increased steadily. The indications for use also have diversified. In this review, the authors provide a panoramic view of extracorporeal membrane oxygenation to provide a foundation of knowledge for anesthesiologists.

Awake tracheal intubation in anticipated difficult airways: LMA Fastrach vs flexible bronchoscope: A pilot study.

STUDY OBJECTIVE: To compare the use of LMA Fastrach intubating laryngeal mask airway (ILMA) to flexible bronchoscopy (FB) for awake intubation in patients with difficult airways. DESIGN: Randomized prospective study. SETTING: Large academic medical center. PATIENTS: Forty adult patients, American Society of Anesthesiologists I-IV, meeting the criteria for awake intubation based on history and physical examination. INTERVENTIONS: After sedation and airway topicalization, patients were randomized to either FB group, n=19, or ILMA group, n=21. All intubations were performed by or under the supervision of an attending anesthesiologists, with variable participation of residents or certified registered nurse anesthetists. A maximum of three attempts were permitted with the assigned technique, to be followed by the alternative method in case of failure. MEASUREMENTS: Times to carbon dioxide (end-tidal carbon dioxide) detection, endotracheal tube placement, number of attempts, training level of operator, and adverse events were recorded. Blood pressure, oxygen saturation, and heart rate were measured. Patients were interviewed the following day regarding their experience and satisfaction. MAIN RESULTS: Overall intubation success rate within three attempts was 95% for both groups. However, successful intubation on the first attempt occurred at a significantly higher rate with ILMA vs FB (95% vs 58%; P=.0028). Total mean time to endotracheal tube placement was also significantly shorter in the ILMA group vs FB (92 vs 246 seconds; P=.0001). There were no adverse events in either group, and patient satisfaction was not significantly different. CONCLUSION: Awake intubation can be performed successfully and expeditiously with the use of LMA Fastrach in patients with a difficult airway and no contraindication to a blind technique. It compared favorably to the use of the fiberoptic bronchoscope in the patient cohort presented in this study.

Neuroanesthesia.

Neuroanesthesia is a subspecialty area of anesthesia that deals with the complex relationships of anesthetic medications, neurosurgical procedures, and the critical care issues that surround the management of these patients. In this chapter we will focus on a brief overview of the key features associated with the management of patients undergoing neurosurgical procedures, including a review of hemodynamic/neurologic effects of anesthetic agents, neurophysiologic monitoring, and unique medical complications associated with these procedures. For successful patient outcomes, multidisciplinary approaches and effective team communications are essential in these high-intensity environments. This chapter should serve as an introduction to the multitude of issues that face the anesthesiologist and surgeon when dealing with this patient population.

Somatosensory evoked potentials help prevent positioning-related brachial plexus injury during skull base surgery.

OBJECTIVE: Evaluate the use of somatosensory evoked potentials (SSEP) monitoring to detect positioning-related brachial plexus injury during skull base surgery. STUDY DESIGN: Prospective cohort observational study. SETTING: University Hospital. SUBJECTS AND METHODS: Patients undergoing skull base surgery had a focused neurologic exam of the brachial plexus performed before and after surgery. Under stable anesthesia, brachial plexus SSEP values were obtained before and after surgical positioning. Significant SSEP changes required a readjustment of arm or neck positions. SSEPs were assessed every 30 minutes. If changes were noted, position was readjusted and SSEPs were reassessed until surgical completion. Demographic data, neurologic exams, SSEP latency, and amplitude values were recorded. Persistent changes were correlated with postoperative neurologic findings. RESULTS: Sixty-five patients, 15 to 77 years old, were studied. Six patients (9.2%) developed SSEP amplitude changes after positioning (average amplitude decrease 72.8%). One patient had a significant latency increase. The sensitivity of SSEP for detection of injury was 57%, while specificity was 94.7%. The average body mass index (BMI) of patients with normal and abnormal SSEPs was 28.7 ± 5.6 versus 29.2 ± 8.0, respectively. Average BMI of patients with postoperative symptoms regardless of SSEP findings was 33.8 ± 4.3. Two patients who had persistent SSEP changes after positioning had BMIs of 40.1 and 31.2 kg/m(2), respectively. Improvement in neurologic findings occurred in all patients after surgery. CONCLUSIONS: This study demonstrates that upper extremity nerve stress can be detected in real time using SSEP and may be of value in protecting patients from nerve injury undergoing lateral skull base surgery.

Opioid-induced hyperalgesia and burn pain.

The treatment of pain produced during the management of burn injury has been an ongoing problem for physicians caring for these patients. The main therapeutic option for analgesia has been the repeated and prolonged use of opioids. The adverse effects of opioids are well known but the long term use of opioids which produces tolerance with accompanying dose escalation and dependence is most problematic. Another potentially important consequence of opioid exposure that sometimes masks as tolerance is that of opioid induced hyperalgesia. This syndrome is manifest as enhanced pain, sensitivity and loss of analgesic efficacy in patients treated with opioids who actually become sensitized to painful stimuli. This article focuses on the treatment of burn pain and how current analgesic therapies with opioids may cause hyperalgesia and affect the adequacy of treatment for burn pain. This article also provides possible modalities to help therapeutically manage these patients and considers future analgesic strategies which may help to improve pain management in this complicated patient population.

Anxiolytic use in the postoperative care unit.

Postoperative anxiety has received less attention historically than preoperative anxiety. Recognition that anxiety occurs throughout the perioperative period has led to increased interest in identifying and treating anxiety in the postoperative period. This article outlines the causes of postoperative anxiety, how it is classified, the effects of anxiety on outcomes after surgery, and some of the clinical procedures that produce the highest levels of anxiety for patients. In addition, an attempt is made to delineate the major risk factors for developing postoperative anxiety and the classic therapeutic modalities used to reduce symptoms and treat the psychological manifestations of anxiety.

Anesthetic and recovery profiles of lidocaine versus mepivacaine for spinal anesthesia in patients undergoing outpatient orthopedic arthroscopic procedures.

STUDY OBJECTIVE: To compare isobaric lidocaine and mepivacaine in outpatient arthroscopic surgery. DESIGN: Prospective, randomized, double-blinded study. SETTING: Ambulatory surgery center affiliated with an academic tertiary-care hospital. PATIENTS: 84 adult, ASA physical status 1, 2, and 3 ambulatory patients, age 18-70 years, undergoing arthroscopic knee surgery. INTERVENTION: Patients were randomized to receive a combination spinal-epidural anesthetic using 80 mg of either isobaric 2% mepivacaine or isobaric 2% lidocaine. Patients also received a femoral 3-in-1 block with 0.5% bupivacaine applied to the affected extremity. MEASUREMENTS: Demographic data and level and duration of the block were recorded. The use of supplemental epidural anesthesia was noted along with frequency of bradycardia, hypotension, and episodes of nausea and vomiting. Duration of block and times to ambulation and voiding were recorded. Delayed variables, including fatigue, difficulty urinating, back pain, and transient neurologic symptoms (TNS) were obtained. MAIN RESULTS: No demographic differences were noted between groups, and surgical duration was similar. Satisfactory anesthesia was achieved in all cases, with no differences noted in hypotension, bradycardia, nausea, or vomiting. Onset of sensory and motor block was similar. Duration of block before epidural supplementation was 94 ± 21 minutes with lidocaine versus 122 ± 23 minutes for mepivacaine (P < 0.011). Times to ambulation and voiding were longer in patients receiving mepivacaine but did not affect PACU stay. Twenty-four and 48-hour recovery was similar with no TNS symptoms reported. CONCLUSION: No major differences were noted between lidocaine and mepivacaine spinal anesthesia. Time to ambulation and voiding were longer in patients who received mepivacaine as was time to first dose of epidural catheter. Neither group had TNS symptoms. Lidocaine and mepivacaine are both appropriate spinal anesthetics for ambulatory orthopedic lower extremity procedures.

The effect of propofol/remifentanil rapid-induction technique without muscle relaxants on intraocular pressure.

STUDY OBJECTIVE: To evaluate the effect of propofol (two mg/kg)/remifentanil (4 µg/kg) on intraocular pressure (IOP) when used for rapid-sequence induction. DESIGN: Randomized, double-blinded trial. SETTING: Ambulatory surgery center. PATIENTS: 47 adult, ASA physical status I and II patients (ages 18-75 yrs), undergoing outpatient, elective, nonophthalmologic surgery. INTERVENTIONS: After premedication with midazolam (two mg) and glycopyrrolate (0.2 mg), standard monitors and a bispectral index (BIS) monitor were applied. Patients underwent rapid-sequence induction with intravenous (IV) propofol two mg/kg and either remifentanil 4 µg/kg IV or succinylcholine 1.5 mg/kg IV. An experienced anesthesiologist, blinded to patient group assignment, performed intubation after 60 seconds. MEASUREMENTS: IOP, heart rate (HR), blood pressure, BIS scores, intubating conditions, and response to intubation (coughing or moving) were recorded at baseline, immediately after completion of induction, one minute after intubation, and three minutes after intubation. Time to return of spontaneous ventilation was also measured. MAIN RESULTS: Remifentanil produced a 39% decrease in IOP immediately after induction, which remained unchanged by laryngoscopy and intubation (P < 0.001). IOP remained below baseline even in patients who coughed or moved in response to intubation. Remifentanil caused a significant decrease in mean arterial pressure of 24% to 31% but no significant change in HR, and it blocked the hemodynamic response to laryngoscopy and intubation while providing intubating conditions comparable to those of succinylcholine. CONCLUSIONS: Propofol/remifentanil induction provides adequate intubating conditions, prevents an increase in IOP, and controls the hemodynamic stress response to laryngoscopy and intubation.

Laparoscopic fundoplication with or without pyloroplasty in patients with gastroesophageal reflux disease after lung transplantation: how I do it.

INTRODUCTION: Several studies have confirmed that gastroesophageal reflux disease (GERD) in lung transplant patients is a risk factor for the development and progression of bronchiolitis obliterans syndrome (BOS), a form of rejection after lung transplantation. Moreover, numerous reports indicate that surgical correction of GERD may control the decline in lung function characteristic of BOS. Although laparoscopic fundoplication is an accepted treatment option for these patients with GERD, the surgical technique, which often includes a laparoscopic pyloroplasty, has not been standardized. METHODS: The purpose of this article is to describe a step-by-step approach to the laparoscopic treatment of GERD in lung transplant patients. We also address specific technical concerns encountered in the surgical management of this high-risk patient population; we provide data on the safety of this operation; and we illustrate the evidence-based rationale for each technical step of the procedure.

Facial nerve electromyographic monitoring to predict movement in patients titrated to a standard anesthetic depth.

BACKGROUND: Facial nerve (FN) monitoring has been accepted as a standard of care in craniofacial, middle ear, and skull-based surgeries as a means of reducing iatrogenic injury, localizing the FN, and predicting postoperative neurologic function. Past studies have also shown that FN electromyographic monitoring (FNEMG) may have some clinical utility as a monitor of anesthetic depth and predicting patient movement. In this study, we evaluated Bispectral Index (BIS) and FNEMG using two different anesthetic techniques to determine whether these monitors can be used to predict movement in patients undergoing skull-based surgical procedures. METHODS: Using a single-blinded, randomized, controlled clinical trial, the relationship between FNEMG monitoring and BIS to predict movement during specific craniofacial and skull-based surgeries performed under general anesthesia was evaluated. In addition, a total IV anesthetic (TIVA) technique, using propofol and remifentanil, was compared with an inhaled anesthetic technique, using desflurane (DES), to determine which regimen provides the best conditions of adequate anesthesia and prevents movement in nonparalyzed patients undergoing a surgical procedure requiring FNEMG monitoring. RESULTS: The TIVA technique produced better hemodynamic conditions compared with DES. No significant differences were noted in BIS values between the two groups. However, FNEMG activity was lower in the TIVA group during emergence from the effects of anesthesia. More patients moved during anesthesia with DES compared with TIVA, and of the 10 patients who moved, eight had significant FNEMG activity. The positive predictive value of the FNEMG for movement was found to be 38%, and the negative predictive value was 95%. There was no significant change from baseline values in hemodynamics or BIS value for patients who experienced movement compared with those who did not move with FNEMG activity. CONCLUSION: This study shows that FNEMG may be an effective monitor for predicting patient movement when undergoing craniofacial and skull-based surgeries. BIS monitoring, however, was not an adequate monitor to predict movement in this patient population. The DES group had more hemodynamic variability and FNEMG activity, whereas TIVA proved to be a more effective anesthetic in preventing patient movement when clinically titrated to produce stable operation conditions. FNEMG was a useful clinical tool to help predict and prevent movement in these patients.

Patient-controlled analgesia combined with either ondansetron or ondansetron plus prochlorperazine for control of pain and nausea and vomiting in patients undergoing abdominal surgery.

STUDY OBJECTIVE: To compare ondansetron with ondansetron plus prochlorperazine, added to a patient-controlled analgesia (PCA) solution for control of postoperative nausea and vomiting (PONV). DESIGN: Prospective, randomized, double-blinded study. SETTING: University hospital. PATIENTS: 150 ASA physical status I, II, and III patients undergoing abdominal surgery. INTERVENTIONS: Patients were given a PCA morphine solution containing either 30 mg of ondansetron (Group O), 30 mg of ondansetron plus 20 mg of prochlorperazine (Group OP), or no antiemetic (Group C; control group). MEASUREMENTS: Demographic data were recorded, along with anesthetic and surgical time, total fluid intake, frequency of Postanesthesia Care Unit (PACU) PONV, discharge time and length of stay, frequency of PONV while on the hospital floor, highest nausea scores, total PCA morphine use, and PCA utilization times. MAIN RESULTS: Demographic and intraoperative variables were similar in all groups. In the first 24 hours after surgery, nausea was higher in Group C than Group OP. Emesis in Group C was twice that of either Group O or Group OP. No differences were noted between groups in PACU PONV. Patients receiving ondansetron plus prochlorperazine when on the hospital floor had a lower frequency of nausea, while patients receiving ondansetron alone had a lower frequency of vomiting than did the control group. The adjusted odds of vomiting doubled for every 12 hours for Group C patients when receiving PCA. CONCLUSIONS: Combination antiemetics added to PCA reduced emetic symptoms after abdominal surgery.

Avoidance and management of trigeminocardiac reflex complicating awake-craniotomy.

The trigeminocardiac reflex occurs from manipulation or stimulation of peripheral branches or the central component of the trigeminal nerve and consists of bradycardia, hypotension, apnea, and increased gastric motility. The efferent limb of the response is mediated by the vagus nerve. This 65-year-old Caucasian male suffered an episode of bradycardia progressing to transient asystole during the course of an awake-craniotomy procedure for tumor resection. The cardiac rhythm changes resolved with administration of intravenous atropine, removal of the precipitating stimulus, and application of topical anesthetic on the dura of the middle cranial fossa. The trigeminocardiac response may complicate the course of a craniotomy and may place an awake, unintubated patient at increased risk for morbidity. The reflex may be prevented by anesthetizing the dura innervated by the trigeminal nerve via injection or topical application of local anesthetic. If encountered, removal of the stimulus, airway protection, and administration of vagolytic medications are measures that need to be considered.

Perioperative and long-term operative outcomes after surgery for trigeminal neuralgia: microvascular decompression vs percutaneous balloon ablation.

OBJECTIVES: Numerous medical and surgical therapies have been utilized to treat the symptoms of trigeminal neuralgia (TN). This retrospective study compares patients undergoing either microvascular decompression or balloon ablation of the trigeminal ganglion and determines which produces the best long-term outcomes. METHODS: A 10-year retrospective chart review was performed on patients who underwent microvascular decompression (MVD) or percutaneous balloon ablation (BA) surgery for TN. Demographic data, intraoperative variables, length of hospitalization and symptom improvement were assessed along with complications and recurrences of symptoms after surgery. Appropriate statistical comparisons were utilized to assess differences between the two surgical techniques. RESULTS: MVD patients were younger but were otherwise similar to BA patients. Intraoperatively, twice as many BA patients developed bradycardia compared to MVD patients. 75% of BA patients with bradycardia had an improvement of symptoms. Hospital stay was shorter in BA patients but overall improvement of symptoms was better with MVD. Postoperative complication rates were similar (21% vs 26%) between the BA and MVD groups. DISCUSSION: MVD produced better overall outcomes compared to BA and may be the procedure of choice for surgery to treat TN.