J. Antonio Aldrete

Epidural fibrosis after permanent catheter insertion and infusion

Forty-six permanent epidural catheters and life-port units were implanted in 43 patients with severe, recurrent low back pain who had been considered not to be candidates for surgical intervention and in whom other therapeutic modalities had failed. Eight cases developed epidural fibrosis (EF). For analgesia, patients received either infusions with preservative-free solutions of fentanyl and bupivacaine or daily boluses of morphine and bupivacaine. Catheters remained from 75 days to 433 days. Signs of EF appeared from 21 days to 320 days after implantation. Pain at injection or resistance to injection were initial manifestations of EF, followed by poor, and eventually, nil analgesic effect. The epidural catheters were made of either polyamide, silicone, or polyurethane. Epidurograms revealed encapsulation, narrowing, and loculation of epidural space with gradually reduced spread of the contrast material. The occurrence of EF limits the permanency of implanted epidural catheters. The infusate does not cause this complication, which appears to be a foreign body reaction due to the presence of the catheter in the epidural space.

Leg edema from intrathecal opiate infusions.

Despite the increasing popularity of intrathecal infusions to treat patients with long‐term non‐cancer‐related pain, this therapy is not without serious side‐effects. Five out of 23 patients who had intrathecal infusions of opiates for longer than 24 months developed leg and feet edema. As predisposing factors, cardiovascular disease, deep venous thrombosis, peripheral vascular disease, and venous stasis of the lower extremities were considered. Every patient who developed pedal and leg edema after the implantation of an infusion pump was also found to have leg edema and venous stasis prior to the time when the pump was inserted. This complication was severe enough to limit their physical activity, and to produce lymphedema, ulcerations and hyperpigmentation of the skin. Reduction of the edema occurred when the dose of the opiate was decreased, and in two cases in which the infusion was discontinued, there was almost complete resolution of the syndrome. It appears that the pre‐existence of pedal edema and of venous stasis is a relative contraindication to the long‐term intrathecal infusion of opiates in patients with chronic non‐cancer pain.

Infections from extended epidural catheterization in ambulatory patients

Background and Objectives. Patients with severe and noncancer pain were treated with prolonged epidural infusions of analgesics in their homes, and the incidence of infection was determined. Methods. In 504 adult patients, 3,164 polyamide lumbar epidural catheters were infused with analgesics of low‐dose bupivacaine and fentanyl intermittenly from 2 to 80 days at their home. When patients developed fever, headache, back pain, and leukocytosis, the presence of infection was confirmed by either computed tomographic scan, epidurogram, or sonogram. Results. Nine infections (0.27%) occurred. Of these, two were epidural abscesses, two were fascitis, and five were cellulitis. Staphylococcus epidermidis was cultured in every case. All of them were treated with 1.5 g intravenous cefuroxime sodium every 8 hours. None of the patients required surgical intervention. In a subgroup of patients treated with the first 1,462 infused catheters, seven infections developed (0.4%), whereas in the subsequent 1,702 cases that received prophylactic penicillin or erythromycin, in 6‐day cycles, there were only two infections (0.11%). Conclusions. Temporary epidural infusions of analgesics up to 80 days are feasible in ambulatory patients with a low rate of infections. Preliminary observations appear to indicate that prophylactic antibiotics given intermittenly further reduce the feasibility of infections. However, these observations may not apply to longer‐lasting epidural infusions.

Reduction of nausea and vomiting from epidural opioids by adding droperidol to the infusate in home-bound patients

In 184 adult patients with severe nonmalignant low back pain from postlaminectomy syndrome, temporary lumbar epidural catheters were infused with either 0.25% bupivacaine 92 mL, fentanyl 600 micrograms, and droperidol 5 mg (Group A), or 0.25% bupivacaine 92 mL, fentanyl 600 micrograms, and NaCl 0.9% 2 mL (Group B). Infusion rates ranged from 0.5 to 2 mL per hour, with an option for turning the infusion off when the patient had no pain and turning it on when the pain returned. Infusions were continued from 2 to 55 days, during which time the patient was at home. In Group A, only two patients had nausea without emesis, while in Group B, nausea occurred in 18 patients (P < 0.04) and four vomited (P < 0.05). The number of patients with headache, pruritus, somnolence, and/or numbness was minimal and without statistically significant group differences. During treatments, pain levels were 2 or less on a 10-cm visual analogue scale. Added to the epidural infusate, droperidol appears to significantly reduce nausea and vomiting in ambulatory patients receiving fentanyl and bupivacaine in extended epidural infusions. The possibility that droperidol potentiates analgesic effects could not be evaluated.

Alberto gutierrez and the hanging drop

p w a h c n the early twenty-first century, we may have trouble understanding how one person can perorm an epidural anesthetic and then proceed to perate on the same patient for a gastrectomy. This ouble role of surgeon-anesthesiologist was played y Alberto Gutierrez from 1932 to 1945, while he as teaching anatomy to medical students and ounding and editing both the Argentinian surgery ournal and the Argentinian anesthesia journal. His imple description of how he observed a hanging rop disappear from the hub of a needle whose tip as in the epidural space is preciously candid and evealing. Realizing that this phenomenon was just heralding sign, he systematically studied it, introuced this technique in Latin America, and offered n alternative approach to identifying the epidural pace worldwide.* Alberto Gutierrez was born in Buenos Aires in 892 into a family of surgeons; his father, an uncle, is brother, two cousins, and a nephew were sureons. Admitted to medical school in 1911, he oined the junior staff of the anatomy department n 1912 and eventually reached the rank of Distinuished Professor in 1942. In his late teens, he ssisted in the operating rooms at the “Gutierrez linic,” where all the cousins treated an elite clienele. As medicine became more hospital oriented,

Chronic subarachnoid administration of 1-(4chlorobenzoyl)-5methoxy-2methyl-1H-indole-3 acetic acid (indomethacin): an evaluation of its neurotoxic effects in an animal model.

Neuraxial administration of nonsteroid antiinflammatory drugs has been suggested as an alternative in the management of intractable pain, but there is little evidence that the neurotoxic effects of indomethacin by this route of administration have been evaluated. In this study, we evaluated histological neurotoxicity of indomethacin after its subarachnoid administration in guinea pigs. The hypothesis tested was “Does subarachnoid administration of indomethacin produce damage in the spinal cord of guinea pigs?” Ten male guinea pigs were anesthetized, and a polyamide catheter connected to a subcutaneous osmotic micro-pump was implanted at the L2-3 level. Animals were randomly assigned in 2 groups of 5 animals each. Indomethacin or saline solution was administered by continuous infusion (0.5 &mgr;L/h) for 14 days. Neurotoxicity was determined by spinal cord histopathology. There was no evidence of toxicity in the histological examinations of either group. These data suggest that subarachnoid administration of indomethacin infusion, at these doses, did not produce lesions typical of neurotoxicity in the spinal cord. We have concluded that epidural administration of indomethacin may be considered an alternative for application in human pain management, although more studies to determine its safety are required.

Body temperature and diaphoresis disturbances in a patient with arachnoiditis.

IMPLICATIONS Arachnoiditis, produced by different causes, is an inflammation of the sac containing the spinal cord and nerve roots. Patients with this disease have severe low back and leg pain, sweating and low grade fever. This case had aberrant skin temperature and sweating in different parts of the body.

Delayed sympathetically maintained pain caused by electrical burn at the current's entry and exit sites

It is not uncommon for sympathetically maintained pain (SMP) to follow electric burns at the site of current entry. The occurrence of SMP at the exit point has not been reported. This report describes a patient who was exposed transiently to a 220W electrical current. After a delay of 3 months, the typical manifestations of SMP appeared on the right hand (entry point); symptoms appeared on the left foot (exit point) after 11 months. Ultrasonography was helpful in identifying the bony and soft tissue changes that occurred with SMP. Serial sympathetic blocks, oral phenytoin, and an intensive physical rehabilitation program were useful in treating this electrically induced SMP.

Alberto Gutierrez: Beyond the Hanging Drop

It is not surprising that many of the earlier contributions to regional anesthesia were made by surgeons, as they had operated under less than ideal conditions with the general anesthetics of the time. Bier, Cushing, Matas, Braun and Pages among others, developed expertise in infiltrating local anesthetics and regional anesthesia to be able to complement their operations trying to achieve better and safer operating conditions. The Argentinian, Alberto Gutierrez (figure 1) was an accomplished author, anatomist and surgeon; like those named above; he initially looked for alternatives to the general anesthetics (ether or chloroform) prevalent in the early YX Century. In order to facilitate and improve the care of his patients, he became acquainted with epidural anesthesia. And by careful observation, he once noted the disappearance of a drop of fluid hanging from the hub of a needle. From then on, he began to study why and how it happened. As he became more passionately involved with “extradural anesthesia,” he not only joined a group of physicians practicing anesthesia, but also founded and edited their journal and participated in their congresses. For the last half century, he has received greater recognition for his description of the “hanging drop method” to identify the epidural space than for the many contributions that he made to the surgical literature.

Intravenous Regional Anesthesia of the Penis: A Historical Vignette

Cuban anesthesiologist Dr. Mirta Abad made me aware of a technique that urologist Vicente Osorio Acosta, another anesthesiologist Gabriel Perez Martinez and herself devised in 1968,1 as alternative anesthetic technique for circumcisions in children and adults. After the initial interest on intravenous regional anesthesia of the upper extremity introduced by Bier2 in 1908, there was a lull in its application with a brief reapproachment when Luis Garcia Herreros3 from Mexico in 1946, Enzo Mourigan Canale4 from Uruguay in 1947, and Flavio Kroeff Pires5 from Brasil in 1954, improved and popularized this technique in Latin America using procaine or tetracaine, as anesthetics. Not until a safer and more effective drug (lidocaine) became available that Holmes6 in 1963, reintroduced this anesthetic technique with eventual universal acceptance. Most of the papers included treatment of the upper and lower extremities. The application of this technique to achieve surgical anesthesia in the penis was done by Osorio Acosta, Perez Martinez and Abad when other anesthetic techniques were contraindicated. The authors accomplished this task by placing a rubber band around the base of the penis to produce ischemia; after partial exsanguination, a vein at the base of the organ was entered with a 26 gauge needle connected to a syringe containing the local anesthetic (either 1% procaine in 2 pts., 1% lidocaine in 2 others and 1% mepivacaine in 6 other instances) proceeding to inject from 5 to 10 ml. The needle was removed and pressure applied at the puncture site. Circumcisions were performed, as soon as the excess prepuce was excised, the tourniquet was released, hemostasis was completed by electrocautery and suture of the incision line was performed. Only one out of 10 patients had discomfort while the last sutures were applied, since closure took longer than 10 mins. from the tourniquet release. Apparently, this was the first preliminary report of the application of intravenous regional anesthesia technique in the penis.