The use of intraoperative epidural or spinal analgesia modulates postoperative hyperalgesia and reduces residual pain after major abdominal surgery

INTRODUCTION: The use of intraoperative multimodal analgesia has clearly improved postoperative pain control, mortality and morbidity after major surgical procedures. However, very few clinical trials have studied the longterm impact of intraoperative epidural or spinal analgesia on chronic postsurgical pain (CPSP) development. Even less studies have evaluated the modulatory effect of intraoperative neuraxial analgesia on objective changes (i.e. mechanical hyperalgesia) reflecting central sensitization. METHODS: The present work compares general anesthesia alone (GA group) versus general anesthesia combined to either intraoperative epidural analgesia (EPID group: combination of bupicavaine, sufentanil and clonidine 1 microg/kg) or spinal analgesia (IT group: either bupivacaine or clonidine 300 microg) on the development of secondary mechanical hyperalgesia and the incidence of CPSP after major abdominal surgery. Data analyzed in the present work involve adult patients undergoing surgical resection of rectal adenocarcinoma who participated in three previously published randomized trials. RESULTS: Intraoperative epidural and particularly spinal analgesia reduced both incidence (p < 0.05 between GA alone and spinal analgesia) and extent (area) of secondary mechanical hyperalgesia surrounding the wound at 48h and 72 h after surgery. The use of intraoperative epidural and spinal analgesia also reduced CPSP incidence. Postoperative area of mechanical hyperalgesia seems positively correlated with the incidence CPSP. CONCLUSION: An effective intraoperative neuraxial block of nociceptive inputs from the wound using multimodal analgesia--specifically when involving spinal analgesics and antihyperalgesic drugs--contributes to prevent central sensitization and hence reduces CPSP after major abdominal procedures.     

Editorial Commentary: Neuraxial Anesthesia Improves Pain After Hip Arthroscopy but Risks Ambulatory Discharge Delay

Hip arthroscopy continues to be one of the fastest-growing orthopaedic procedures nationally, and pain control following these procedures can be challenging. As regional anesthesia techniques for this population have shown to have limited benefits, pain management for hip arthroscopy focused on multimodal analgesia and preventive analgesia, interventions that reduce postoperative hyperalgesia. The use of neuraxial anesthesia such as spinal and epidural anesthesia, established preventive analgesic anesthetic techniques, has demonstrated to improve postoperative pain in orthopaedic surgery when compared with general anesthesia. This promising finding highlights that despite potential disadvantages of neuraxial anesthesia, such as a small risk for complications or delayed resolution of the neuraxial block that could delay discharge, neuraxial anesthesia could be a suitable anesthetic technique for ambulatory orthopaedic surgery.     

Opioid-free analgesia following total knee arthroplasty--a multimodal approach using continuous lumbar plexus (psoas compartment) block, acetaminophen, and ketorolac.

BACKGROUND AND OBJECTIVES: Traditionally, postoperative analgesia following total knee arthroplasty (TKA) has been provided by neuraxial or peripheral regional techniques with supplemental administration of opioids. We report an alternative method of postoperative pain management for patients undergoing TKA in whom the use of systemic or neuraxial opioids may result in significant side effects. CASE REPORT: A 74-year-old woman with a history of protracted nausea and vomiting after systemic and neuraxial opioid administration presented for left total knee arthroplasty. A spinal anesthetic with postoperative continuous lumbar plexus (psoas) analgesia was planned. A quadriceps motor response was elicited and a 20-gauge catheter was advanced through an 18-gauge insulated Tuohy needle into the psoas sheath. After 30 mL of bupivacaine 0.5% with 100 microg clonidine was administered through the psoas catheter, a spinal anesthetic (2 mL 0.5% bupivacaine at the L2-3 interspace) was performed. A continuous psoas infusion of 0.2% bupivacaine with 2 microg/mL clonidine at 8 mL/h was initiated in the recovery room. The psoas infusion was subsequently changed to 0.2% bupivacaine without clonidine and the rate increased to 10 mL/h. Supplemental analgesia with oral acetaminophen 1 g every 4 to 6 hours alternating with intravenous ketorolac 15 mg every 6 hours provided satisfactory analgesia, with visual analog scale (VAS) scores of 0 to 2 at rest and 3 to 4 with movement. The psoas catheter was removed 48 hours postoperatively because of prolongation of the prothrombin time. VAS scores remained 0 to 3 throughout the remainder of her hospitalization. CONCLUSION: A multimodal approach consisting of continuous lumbar plexus (psoas) block and nonopioid analgesics successfully provided postoperative pain relief in our patient and facilitated her physical rehabilitation after total knee arthroplasty.     

Analgesic pharmacology: II. Specific analgesics

Methods of treatment are different for acute and chronic pain. For acute pain, analgesics such as nonsteroidal anti-inflammatory drugs and opiates are commonly used, sometimes combined with regional anesthesia, such as peripheral nerve block or peridural local anesthesia. The mechanism of transition from an acute to a chronic pain state is poorly understood. Only NMDA receptor antagonists and epidural morphine have shown relatively consistent results as preemptive analgesics. Agents more successfully used to manage chronic pain include those that modify the neurochemistry of the spinal cord dorsal horn, such as tricyclic antidepressants, anticonvulsants, gamma-amino butyric acid agonists, local anesthetic analogs, and NMDA antagonists. Opiates may be used chronically, but tolerance and lack of efficacy may then develop. In selected patients with refractory chronic pain, centrally administered analgesics may be considered, including opiates, dilute local anesthetic, NMDA receptor antagonists, clonidine, midazolam, baclofen, or calcium channel blockers. For both acute and chronic pain, a single agent may be less effective than combinations of analgesics with different mechanisms of action.     

Does the evidence support the use of spinal and epidural anesthesia for surgery?

When spinal and epidural anesthesia were introduced into clinical practice, their primary use was as an alternative to general anesthesia. Later, largely as a result of the realization that opioids could be safely and effectively used to produce selective spinal analgesia, spinal and epidural (neuraxial) analgesia began to be used specifically for the treatment of perioperative pain. We present a systematic review of the literature on neuraxial anesthesia and analgesia, new meta-analyses that illustrate the powerful effect of improvements in perioperative safety in general on the ability of neuraxial techniques to make a difference, and a consideration of why a literature analysis does not provide clear answers.     

Interactions between general and regional anesthesia

Neuraxial blockade is commonly used to abolish sensations elicited by noxious stimuli during surgical procedures. Proven advantages of combined anesthesia include early recovery from general anesthesia and postoperative analgesia, together with likely decreases in blood loss, cardiac dysrhythmias, or ischemic events and postoperative deep vein thrombosis. The side effects of the technique are related to the dose or site of local anesthetic administration and to light general anesthesia, which can result in awareness during surgery. Varying degrees of synergistic interactions have been reported among the drugs used to achieve the anesthetic state. Spinal anaesthesia appears to have sedative effects, and local anesthetics used for neuraxial blockade have been found to reduce the induction and maintenance dosage of midazolam, thiopental, propofol and inhaled anesthetics. The growing interest in combining local and general anesthesia has led to studies investigating possible interactions between general anesthesia and local anesthetics administered via spinal or epidural routes. Neuraxial blockade reduces sedative and anesthetic requirements by decreasing ascending sensory input into the brain. This has important clinical implications, as anesthetists should expect to reduce anesthetic and sedative drug doses during neuraxial blockade, unless the blockade involves lower dermatomes alone. Clinical practice of anesthesia is a polypharmacy, wherein the anesthetic state is the net result of the action of different drugs and their interaction in the presence of a surgical stimulus.     

Alpha 2 agonists in regional anesthesia and analgesia

Clonidine is a partial alpha 2 adrenergic agonist that has a variety of different actions including antihypertensive effects as well as the ability to potentiate the effects of local anesthetics. It can provide pain relief by an opioid-independent mechanism. It has been shown to result in the prolongation of the sensory blockade and a reduction in the amount or concentration of local anesthetic required to produce perioperative analgesia. Different routes for the administration of regional anesthesia, including intravenous, intrathecal and epidural ones, as well as the addition of clonidine for peripheral neural blockade, have been described. It has been also used for intra-articular administration. The latest articles describing the use of clonidine in regional anesthesia are discussed. Most authors agree that the use of clonidine for regional neural blockade in combination with a local anesthetic results in increased duration of sensory blockade with no difference in onset time. The addition of clonidine to the local anesthetic opioid mixtures seems to produce analgesia of longer duration, more rapid onset and higher quality. The higher doses of clonidine were associated with a more cephalad spread of the spinal blockade and increased sedation and hypertension. When clonidine is added to a fentanyl-bupivacaine mixture for epidural labor analgesia, it seems to provide satisfactory analgesia of a longer duration than that produced by the fentanyl-bupivacaine combination alone. Similar results were found when epidural analgesia using levobupivacaine with clonidine was used in patients undergoing total hip arthroplasty. Less clear results were seen when clonidine was used for caudal anesthesia in a pediatric patient population. The addition of clonidine to intravenous regional anesthesia resulted in prolongation of the tourniquet time and improvement of postoperative analgesia. However, the latter was found to be short-lived. In another study, the effects of clonidine used for intra-articular administration in combination with morphine were investigated. These authors found a significantly higher rate of satisfaction in the group of patients receiving clonidine plus morphine. Although several recent studies have shown certain benefits from the use of clonidine for regional anesthesia, further investigations are necessary to clarify its role.     

Combined use of neuraxial and general anesthesia during major abdominal procedures in neonates and infants

With the advent of ultrasound and improvements in equipment, the applications of regional anesthesia in the pediatric population have continued to expand. Although frequently used for postoperative analgesia or as a means of avoiding general anesthesia in patients with comorbid conditions, the adjunctive use of regional anesthesia during general anesthesia may effectively decrease the intraoperative requirements for intravenous and volatile agents, thereby providing a more rapid awakening and earlier tracheal extubation. More recently, the limitation of the requirements for volatile and other anesthetic agents may be desirable, given concerns regarding the potential impact of these agents on neurocognitive outcome in neonates and infants. Several authors have demonstrated the potential utility of combining a neuraxial technique (spinal or epidural anesthesia) with general anesthesia in neonates and infants undergoing intraabdominal procedures. We review the literature regarding the combined use of neuraxial and general anesthesia in neonates and infants during major abdominal surgery, discuss its potential applications in this population, and review the techniques of such practice.     

A parturient with severe bullous emphysema from intravenous drug abuse

A parturient with severe talcosis-induced, bullous emphysema presented for urgent cesarean delivery. Respiratory effects of anesthesia, positioning for delivery and residual effects of postoperative analgesics all potentially affect the choice of anesthetic technique and drugs used in a patient with severe emphysema. This parturient was given epidural anesthesia for delivery and postoperative analgesia maintained with epidural infusion of bupivacaine and clonidine.     

An evaluation of intrathecal bupivacaine combined with intrathecal or intravenous clonidine in children undergoing orthopedic surgery: a randomized double-blinded study

Background: Propofol is a popular agent for providing intraoperative sedation in pediatric population during lumbar puncture and spinal anesthesia. Adjuvant‐like clonidine is used increasingly in pediatric anesthesia to provide postoperative analgesia with a local anesthetic agent. The aim of this study was to assess the effects of intrathecal and intravenous clonidine on postoperative analgesia/sedation and intraoperative requirements of propofol after intrathecal bupivacaine for orthopedic surgery in children. Methods: Fifty‐nine ASA I and II children aged 6–8 year undergoing orthopedic surgery were randomized to receive intrathecal 0.5% bupivacaine 0.2–0.4 mg·kg^?1 and intravenous 2 ml saline (Group B), intrathecal 0.5% bupivacaine 0.2–0.4 mg·kg^?1 plus 1 μg·kg^?1 clonidine and intravenous 2 ml saline (Group BCit), and 0.5% bupivacaine 0.2–0.4 mg·kg^?1 and intravenous 1 μg·kg^?1 clonidine in 2 ml of saline (Group BCiv). Intraoperative sedation was maintained with 20–50 μg·kg^?1·min^?1 of propofol infusion. The requirements of propofol, time to first rescue analgesia, and postoperative pain or sedation scores were assessed. The duration of motor and sensory blocks and perioperative adverse events were determined. Results: Clonidine significantly prolonged the time to first rescue analgesia and reduced the requirements of propofol sedation whether administered intravenously or intrathecally. The mean Children and Infants Postoperative Pain Scale scores of children were significantly lower in groups BCit and BCiv than in group B. Postoperative sedation scores were higher in groups BCit and BCiv than in group B. Intrathecal clonidine significantly prolonged the time to regression of the sensory block and recovery of motor block. There were no significant differences among the three groups regarding the incidence of perioperative adverse events. Conclusion: Intrathecal or intravenous clonidine similarly provided better postoperative analgesia and sedation and reduced the requirements of propofol. Only intrathecal clonidine prolonged the duration of sensory and motor blocks.     

Neuraxial anesthesia and analgesia in patients with preexisting central nervous system disorders

Historically, the use of regional anesthetic techniques in patients with preexisting central nervous system (CNS) disorders has been considered relatively contraindicated. The fear of worsening neurologic outcome secondary to mechanical trauma, local anesthetic toxicity, or neural ischemia is commonly reported. We examined the frequency of new or progressive neurologic complications in patients with preexisting CNS disorders who subsequently underwent neuraxial blockade. The medical records of all patients at the Mayo Clinic from the period 1988 to 2000 with a history of a CNS disorder who subsequently received neuraxial anesthesia or analgesia were retrospectively reviewed. One-hundred-thirty-nine (n = 139) patients were identified for study inclusion. Mean patient age was 60 +/- 17 yr. Gender distribution was 86 (62%) males and 53 (38%) females. An established CNS disorder diagnosis was present a mean of 23 +/- 23 yr at the time of surgical anesthesia, with 74 (53%) patients reporting active neurologic symptoms. Spinal anesthesia was performed in 75 (54%) patients, epidural anesthesia or analgesia in 58 (42%) patients, continuous spinal anesthesia in 4 (3%) patients, and a combined spinal-epidural technique in 2 (1%) patients. Bupivacaine was the local anesthetic most commonly used in all techniques. Epinephrine was added to the injectate in 72 (52%) patients. There were 15 (11%) technical complications, with the unintentional elicitation of a paresthesia and traumatic needle placement occurring most frequently. A satisfactory block was reported in 136 (98%) patients. No new or worsening postoperative neurologic deficits occurred when compared to preoperative findings (0.0%; 95% confidence interval, 0.0%-0.3%). We conclude that the risks commonly associated with neuraxial anesthesia and analgesia in patients with preexisting CNS disorders may not be as frequent as once thought and that neuraxial blockade should not be considered an absolute contraindication within this patient population.     

Sameridine is safe and effective for spinal anesthesia: a comparative dose-ranging study with lidocaine for inguinal hernia repair

Sameridine is a new compound with local anesthetic and analgesic properties when injected intrathecally. We studied the anesthetic and analgesic efficacy of three doses of isobaric sameridine (15, 20, and 23 mg) compared with 100 mg of hyperbaric lidocaine for spinal anesthesia in 140 healthy male patients undergoing inguinal hernia repair. Patients received spinal anesthesia with 4 mL of the study drug injected at the L2-3 or L3-4 interspace in the lateral decubitus position. All three doses of sameridine provided spinal anesthesia similar to lidocaine, with a slightly longer time to reach peak block height. The failure rate was highest in the 15-mg sameridine group, and accrual was discontinued in that group after 35 patients. The duration of blockade was shorter with lidocaine, but the time to voiding and ambulation was similar in all groups. Patients receiving sameridine were less likely to request morphine for postoperative analgesia and were less likely to request any analgesia in the first 4 h after injection of the drug. Use of oral analgesics (hydrocodone and acetaminophen) was similar in all groups after the first 4 h of the 24-h observation. We conclude that, in the three doses studied, sameridine provided spinal anesthesia similar to lidocaine, but with residual analgesia after drug injection that reduced the need for systemic analgesics in the first 4 h postoperatively. Implications: In this clinical trial, we show the potential efficacy of a class of drugs that can produce both spinal anesthesia and postoperative analgesia when used for hernia repair.     

Influence of intravenous clonidine pretreatment on anesthetic requirements during bispectral EEG-guided sevoflurane anesthesia

STUDY OBJECTIVE: To assess the anesthetic effects of clonidine during sevoflurane anesthesia guided by the bispectral index (BIS), which is a processed EEG variable correlated with anesthetic-hypnotic depth. DESIGN: Placebo-controlled, double-blind clinical trial. SETTINGS: Elective laparoscopic surgery. PATIENTS: 60 ASA physical status I patients scheduled for laparoscopic surgery. INTERVENTIONS: Patients received either clonidine (3 micrograms/kg, 15 min before induction) or placebo premedication for a sevoflurane-induced and sevoflurane-maintained anesthesia. Sevoflurane was titrated against a BIS held between 40 and 50. Analgesia was provided by local infiltration with bupivacaine. Need for postoperative analgesia was recorded. RESULTS AND CONCLUSION: Mean sevoflurane requirements were not lower with clonidine pretreatment. There was statistically better perioperative hemodynamic stability (i.e., fewer episodes of hypertension and tachycardia) without clinical relevance. A decreased need for postoperative analgesia was observed.     

Differentialindikation zentraler und peripherer Leitungsanästhesien

Serious neurological complications caused by spinal hematoma or abscess following central neuraxial block have been reported more often during the last years. In contrast, severe complications are extremely rare associated with peripheral nerve blocks. Concerned about the safety of spinal and epidural anesthesia, we encourage the use of peripheral regional techniques for procedures on the lower extremity and especially for postoperative regional analgesia. Motor block due to lumbar epidural anaesthesia using high concentrations of local anesthetic makes spinal hematoma or abscess difficult to recognize. Therefore, low concentrations of local anesthetic should be used for postoperative epidural analgesia. Any increase in motor block following neuraxial blockade should raise the suspicion of a spinal compression (e.g. hematoma or abscess). Other symptoms are back pain, radicular pain or paresthesia and incontinence. Disastrous neurological injuries can only be prevented by immediate diagnosis (MR, CT or myelography) and therapy (surgical decompression).     

Cardiorespiratory and Spinal Cord Blood Flow Effects of Intrathecal Neostigmine Methylsulfate, Clonidine, and Their Combination in Sheep

Background: Intrathecal neostigmine may produce analgesia by itself and may enhance analgesia from spinal clonidine. Before clinical trials, the spinal cord blood flow effects of these drugs alone and in combination should be examined in animals.

Methods: Conscious, nonpregnant ewes with indwelling vascular and thoracic spinal catheters received intrathecal injection of 0.2 or 2 mg neostigmine, 0.2 mg clonidine, or 2 mg neostigmine plus 0.2 mg clonidine. Mean systemic and pulmonary arterial and central venous pressures, heart rate, and cardiac output were monitored, arterial blood was sampled for blood gas tensions and pH, and spinal cord blood flow was determined by colored microsphere injection before and at 15, 60, and 240 min after spinal study drug injection.

Results: Neostigmine alone did not affect cardiorespiratory variables or spinal cord blood flow. Intrathecal clonidine alone decreased systemic arterial and central venous pressures, whereas these effects were not observed with addition of neostigmine. Clonidine or neostigmine alone or the combination of clonidine and neostigmine did not affect spinal cord blood flow.     

Low-dose intrathecal clonidine combined with sufentanil as analgesic drugs in abdominal gynecological surgery

STUDY OBJECTIVES: To determine whether a low dose of spinal clonidine either alone or combined with sufentanil would provide effective analgesia following abdominal surgery, as a supplement to bupivacaine spinal anesthesia. DESIGN: Randomized double-blind study. SETTING: Gynecological surgery, teaching hospital. PATIENTS: 73 ASA physical status I and II patients undergoing gynecological abdominal surgery with spinal anesthesia. INTERVENTIONS: Patients were randomly assigned to one of four groups and prospectively studied to examine anesthesia, analgesia, and adverse effects. The control group received saline as the test drug; the sufentanil group received 10 microg of sufentanil; the clonidine group received 30 microg of clonidine; and the sufentanil/clonidine group received 5 microg of sufentanil plus 15 microg of clonidine. All groups received intrathecal 15 mg of bupivacaine (3 mL) plus the intrathecal test drug (2 mL). The concept of visual analog scale (VAS) was introduced. All patients were premedicated with intravenous midazolam. Rescue analgesics were available. MEASUREMENTS AND MAIN RESULTS: The groups were demographically the same. Sensory block to pinprick at 10 min was higher for clonidine and sufentanil/clonidine groups compared to the control group (p < 0.02). Anesthetic time (Bromage score 2) was also longer for clonidine and sufentanil/clonidine groups compared to the control and sufentanil groups (p < 0.05). Time to first rescue analgesics was shorter in the control group compared to the other groups (p < 0.02). The number of IM diclofenac dose injections in 24 hours was higher in the control group compared to all other groups (p < 0.05). The incidence of adverse effects and ephedrine consumption were similar among groups. CONCLUSIONS: Intrathecal 15- and 30-microg clonidine doses expanded the anesthesia sensory block and duration of motor block, and provided analgesia.     

Pain management after major orthopaedic surgery: current strategies and new concepts

Several recently developed analgesic techniques effectively control pain after major orthopaedic surgery. Neuraxial analgesia provided by epidural and spinal administration of local anesthetics and opioids provides the highest level of pain control; however, such therapy is highly invasive and labor intensive. Neuraxial analgesia is contraindicated in patients receiving low-molecular-weight heparin. Continuous plexus and peripheral neural blockades offer excellent analgesia without the side effects associated with neuraxial and parenteral opioids. Intravenous patient-controlled analgesia allows patients to titrate analgesics in amounts proportional to perceived pain stimulus and provide improved analgesic uniformity. Oral sustained-release opioids offer superior pain control and greater convenience than short-duration agents provide. Opioid dose requirements may be reduced by coadministration of COX-2-type nonsteroidal analgesics.     

Cardiac arrest during neuraxial anesthesia: frequency and predisposing factors associated with survival

The frequency and predisposing factors associated with cardiac arrest during neuraxial anesthesia remain undefined, and the survival outcome data are contradictory. In this retrospective study, we evaluated the frequency of cardiac arrest, as well as the association of preexisting medical conditions and periarrest events with survival after cardiac arrest during neuraxial anesthesia between 1983 and 2002. To assess whether survival after cardiac arrest differs for patients who arrest during neuraxial versus general anesthesia, data were also obtained for patients who experienced cardiac arrest under general anesthesia during similar surgical procedures during the same time interval. Over the 20-yr study period at the Mayo Clinic, there were 26 cardiac arrests during neuraxial blockade and 29 during general anesthesia. The overall frequency of cardiac arrest during neuraxial anesthesia for 1988 to 2002 was 1.8 per 10,000 patients, with more arrests in patients receiving spinal versus epidural anesthesia (2.9 versus 0.9 per 10,000; P = 0.041). In 14 (54%) of the 26 patients who arrested during a neuraxial technique, the anesthetic contributed directly to the arrest (high sympathectomy or respiratory depression after sedative administration), whereas in 12 (46%) patients, the arrest was associated with a specific surgical event (cementing of joint components, spermatic cord manipulation, reaming of the femur, and rupture of amniotic membranes). Patients who arrested during general anesthesia had a higher ASA classification than those who arrested during a neuraxial block (P = 0.031). Hospital survival was significantly improved for patients who arrested during neuraxial anesthesia versus general anesthesia (65% vs 31%; P = 0.013). The association of improved survival with neuraxial anesthesia remained statistically significant after adjusting for all patient/procedural characteristics, with the exception of ASA classification and emergency procedures. We conclude that a cardiac arrest during neuraxial anesthesia is associated with an equal or better likelihood of survival than a cardiac arrest during general anesthesia.     

Anesthetic management of a parturient with VACTERL association undergoing Cesarean delivery

Purpose

We present the anesthetic management of a parturient with VACTERL association undergoing combined regional and general anesthesia for Cesarean delivery. Defined as a syndrome, VACTERL association comprises at least three of the following abnormalities: vertebral, anal atresia, cardiac, tracheoesophageal, renal, and limb.

Clinical features

The patient’s anatomic abnormalities and comorbidities comprised severe cervicothoracic scoliosis, kyphoscoliosis, congenitally fused ribs, and severe restrictive lung disease. She had a Mallampati class 3 airway, a right laterally flexed neck, and reduced mandibular protrusion. We performed a lumbar spine ultrasound for epidural placement which was used to provide peri- and postoperative analgesia. Due to the anticipated difficult tracheal intubation, the patient underwent an awake fibreoptic intubation and subsequently received general anesthesia. The patient’s trachea was extubated on the first postoperative day, and she received adequate post-Cesarean epidural analgesia.

Conclusion

This case highlights the challenges that anesthesiologists face when managing parturients at extremely high risk for perioperative anesthetic morbidity due to the presence of severe pre-existing disease, anticipated difficult airway, and major spinal abnormalities complicating neuraxial anesthesia. We used a combined general and epidural anesthetic approach to control ventilation, provide effective postoperative analgesia, and reduce the risk of anesthetic-related perioperative morbidity. An individualized approach should be considered for the anesthetic management of high-risk pregnant patients with complex and multiple medical and surgical morbidities undergoing labour and delivery.     

Failed spinal anesthesia after a psoas compartment block

PURPOSE: To report the case of a patient who experienced failed spinal anesthesia following a psoas compartment block (PCB) and discuss its implications. CLINICAL FEATURES: A 70-yr-old male was scheduled for a right total hip arthroplasty. He agreed to a PCB for postoperative analgesia and a spinal anesthetic. The spinal anesthetic was performed after completion of the PCB. Free flow of clear fluid was demonstrated at the beginning and at the end of the presumed intrathecal injection. General anesthesia had to be induced because of failure of the spinal anesthetic. The patient awoke from his general anesthetic with a functional PCB and no evidence of residual neuraxial anesthesia. The possibility of epidural spread of local anesthetic from the PCB impairing the ability to perform spinal anesthesia is discussed and reviewed. We hypothesize that local anesthetic in the epidural space may have falsely reassured the anesthesiologist that the needle was properly placed. CONCLUSION: We describe a case of failed spinal anesthesia following a PCB and discuss its implications.