Lloyd Saberski

Identification of the Epidural Space: Is Loss of Resistance to Air a Safe Technique? A Review of the Complications Related to the Use of Air

Background and Objectives. The major determinant of successful epidural anesthesia is the localization of the epidural space. The manual loss of resistance technique is widely used by anesthesiologists in identifying the epidural space. Should air or saline be used in detecting the point of loss of resistance? No consensus exists as to which technique is superior, and individual providers currently use the technique with which they are most comfortable. The incidence of adverse effects associated with the use of epidural air is unknown and may be underreported as the effects may be unrecognized or considered trivial. The authors comprehensively review the complications of epidural air from published reports. Methods. Using the appropriate key words, the authors searched the Medline (National Library of Congress) scientific data bank from 1966 to 1995, for case reports of epidural complications. Results. There are few prospective, controlled, double‐blinded studies comparing the relative merits of using air versus saline for the loss of resistance technique of epidural placement. There are, however, numerous case reports. Complications associated with the use of air for the loss of resistance technique included pneumocephalus, spinal cord and nerve root compression, retroperitoneal air, subcutaneous emphysema, and venous air embolism. Additionally, inadequate analgesia and paresthesia have been associated with the loss of resistance technique using air. Transient and permanent neurologic sequelae have been attributed to some of the complications. The simultaneous administration of nitrous oxide and positive. Pressure ventilation has also been reported to expand localized collections of air, resulting in heightened symptoms. Conclusions. The potential complications associated with the use of air for identifying the epidural space with the loss of resistance technique may outweigh the benefits. The use of saline to identify the epidural space may help to reduce the incidence of these complications.

Oral capsaicin provides temporary relief for oral mucositis pain secondary to chemotherapy/radiation therapy

Pain from oral mucositis afflicts from 40% to 70% of patients receiving chemotherapy or radiation therapy. Current methods of clinical pain management (for example, topical anesthetics, systemic analgesics) have limited success. In a pilot study, we examined the ability of oral capsaicin to provide temporary relief of oral mucositis pain. Capsaicin, the active ingredient in chili peppers, desensitizes some neurons and has provided moderate pain relief when applied to the skin surface. Oral capsaicin in a candy (taffy) vehicle produced substantial pain reduction in 11 patients with oral mucositis pain from cancer therapy. However, this pain relief was not complete for most patients and was only temporary. Additional research is needed to fully utilize the properties of capsaicin desensitization and thus optimize analgesia.

Direct visualization of the lumbosacral epidural space through the sacral hiatus.

M yeloscopy, or the direct visualization of the spinal canal and its contents, was first reported in 1931 from the pioneering work of Michael Burman (1). With each decade since then, myeloscopists and epiduroscopists have attempted to develop a means of visualization that would be easy and safe to apply to medical practice. Unfortunately, until the recent advent of both flexible fiberoptic light sources and optics (2) this could not be achieved. The recent work of Heavner et al. (3) and Schutze and Kurtze (4) indicated that the lumbar epidural space can be accessed with fiberoptic systems. However, the angle of entry into the lumbar epidural and the intrathecal spaces made steering difficult. Steering is thought to be a required feature to make this technology clinically useful. Described in this report is passage of a fiberoptic system from the sacral hiatus into a saline-expanded lumbar epidural space. Most importantly, the straight entry allowed for easier maneuvering of the fiberoptic scope and laid the foundation for future fiberoptic guided procedures.

Persistent radiculopathy diagnosed and treated with epidural endoscopy

Caudal epidural endoscopy has recently been introduced as an alternative technique for directed injection of epidural steroids and lysis of adhesions [1]. It has the distinct advantage of providing a three-dimensional color view of nerve roots, blood ressels, and the dura mater with or without pathologic adhesions. This improves targeting and probably serves as an advantage over standard epidural steroid injections and perhaps even two-dimensional fluoroscopic manipulations of the epidural space [2]. In order to achieve successful placement of the catheter for injection and the flushing away of fibrinous material, it is necessary to direct the catheter and normal saline stream to the lesions under consideration. However, the fiberoptic catheter inserted through the vein dilator is difficult to steer despite gentle curves on the end of the fiberscope and various clockand counterclockwise rotations (Fig. 1). Therefore, it is essential to develop a more efficient and reliable means of steering. This has been accomplished with development of the multilumen steering handle (Fig. 2), currently available from Myelotec (Alpharetta, Georgia, USA) under a U.S. Food and Drug Administration (F.D.A.) Investigational Device Protocol, through which a fiberoptic bundle is placed. Described

ASSESSMENT OF DIURNAL VARIATION OF CEREBROSPINAL FLUID TRYPTOPHAN AND 5-HYDROXYINDOLEACETIC ACID IN HEALTHY HUMAN FEMALES

The role of serotonin (5-HT) in the pathogenesis and treatment of major neuropsychiatric disorders, including mood and anxiety disorders, continues to be the subject of extensive research. Previous studies examining central 5-HT functioning measured cerebrospinal fluid (CSF) levels of 5-hydroxyindoleacetic acid (5-HIAA) by using single or multiple lumbar punctures. A number of investigators have demonstrated the feasibility of continuous CSF sampling via an indwelling lumbar catheter to study CSF neurochemistry in healthy subjects and patients with neuropsychiatric illness. Four healthy female volunteers, aged 21-34 years, underwent continuous CSF sampling. CSF was collected at a constant rate of 1 ml every 10 minutes over a 30-hour period, with levels of tryptophan (TRP) and 5-HIAA measured every hour. Plasma was also obtained hourly for TRP determination. The results of this study indicate that CSF 5-HIAA, CSF TRP, and plasma TRP levels showed variation over time, but failed to show diurnal fluctuation. Intra-individual coefficients of variation determined for CSF 5-HIAA, CSF TRP, and plasma TRP ranged from 9.2 to 14.9%, 8.8 to 14.6%, and 14.7 to 19.0%, respectively. Continuous CSF sampling is safe and feasible in humans, and may prove useful for studies of central 5-HT neurotransmission in neuropsychiatric illness.

Sphenopalatine ganglion block for treatment of sinus arrest in postherpetic neuralgia.

A 64‐year‐old woman presented with bradycardia from sinus pauses during exacerbations of postherpetic trigeminal distribution neuralgia. She had underlying systemic lupus erythematosus. Sphenopalatine ganglion blockade was employed to treat her pain. The episodes of bradycardia resolved with successful alleviation of pain. This report emphasizes that a sphenopalatine ganglion blockade can be employed in the treatment and prevention of sinus arrest associated with postherpetic trigeminal distribution neuralgia.

Complications of Antidepressants, Anticonvulsants, and Antiarrhythmics for Chronic Pain Management

Adjunctive drugs play an important role in the management of chronic pain states. Recent analysis of previous studies has confirmed the efficacy of both anticonvulsant and antidepressant medications in the treatment of a variety of chronic pain conditions. There are few trials investigating the use of antiarrhythmic drugs in chronic pain. The studies that exist do suggest that antiarrhythmics may be of use in some cases. There are serious toxicities associated with all of these agents. Many of these are so troublesome as to require cessation of the drug. There are also some alarming idiosyncratic reactions associated with their use. Recent advances have included the introduction of gabapentin and lamotrigine. Both of these have significantly fewer side effects and are better tolerated. Currently there is little clinical data regarding their efficacy in chronic pain states. Newer antidepressants do not appear to be significantly better than placebo in treating pain. Their faster onset and fewer side effects may make them better tolerated in the treatment of associated depression. Antiarrhythmic agents, due to potentially lethal side effects, are best reserved for resistant pain unresponsive to more conventional drugs.

Neuroablative techniques for cancer pain management

Neurolytic/neurodestructive blockade can be therapeutic for some pain syndromes. In general, it is fell that the longer a pain syndrome is present, the less likely that nay single intervention including neurolytic/neurodestructive blockade, will be singularly successful. A balanced program is recommended and should include physical modalities along with medical, surgical, and anesthetic intervention when required. In this article the reader studies the technologies and techniques of neurodestruction which can be utilized clinically as part of balanced analgesia.

Rediscovery of Ganglion Impar Block via Coccygeal Joints

laterally along an intercostal space or whether it moves parallel to the vertebral column as it should. In the former case, the catheter is withdrawn and the bevel of the needle is redirected and slightly rotated towards the spinal column to avoid an intercostal insertion and consequent unwanted single-dermatome analgesia. The catheter is fixed to the skin at its emergence. Soni et al. have reported on the video-assisted placement of a paravertebral catheter,5 inserting a Tuohy needle through the fifth intercostal space in the posterior axillary line and feeding the catheter under video control into the extrapleural space. Unlike Soni et al. we deliberately chose to maintain the same posterior percutaneous approach as in the blind technique. Direct viewing of the anatomical landmarks makes the technique easy to learn and affords a good margin of safety. In conclusion, video-assisted percutaneous paravertebral catheterization seems to be a feasible method for postoperative pain relief after VATS. It mainly benefits young individuals, who are particularly susceptible to the pain caused by chest tubes and rib cage excursion upon breathing.

Comment on epiduroscopic changes in patients undergoing single and repeated epidural injections.

To the Editor: I read with interest “Epiduroscopic Changes in Patients Undergoing Single and Repeated Epidural Injections” by Kitamura et al. (1). The authors attribute epidural changes, hemorrhage, and congestion to epidural catheter placement and administration of local anesthetic. While indeed this could be a cause of their findings, the authors neglected the possibility that underlying pathology (lumbar disk herniation, postherpetic neuropathy, and Buerger’s disease) in the treatment group made contributions. A control group of patients with lumbar disk herniation, postherpetic neuropathy, and Buerger’s disease is required in order to form conclusions regarding epidural anesthesia/analgesia. Nucleus pulposus when injected or displaced into the epidural space will cause an inflammatory reaction (2). Such an effect is thought to be mediated via at least phospholipase A2 (3) and has been observed with epiduroscopy (4,5). I am unaware of any epiduroscopic data on the appearance of the epidural space in patients with postherpetic neuropathy or Buerger’s disease.