Gordon R. Bell

Spinal anesthesia for elective lumbar spine surgery

STUDY OBJECTIVE To evaluate a large series of elective lumbar spine surgical procedures by a single surgeon whose patients were all offered spinal anesthesia. DESIGN Retrospective chart review. SETTING Tertiary-care teaching hospital. MEASUREMENTS AND MAIN RESULTS The records of all elective lumbar spine procedures between 1984 and 1995 performed by one surgeon (GRB) were obtained, and 803 were identified. Of those 803 patients, 611 accepted spinal anesthesia. Data collected included patient demographics, details of the spinal and general anesthesia, perioperative complications, and impact of the spinal anesthetic options on the outcome of spinal anesthesia. General and spinal anesthesia patients were comparable for age, gender, height, and ASA physical status. Patients who received spinal anesthesia were significantly heavier than the general anesthesia patients. Among perioperative complications, nausea and deep venous thrombosis occurred significantly more often in the general than spinal anesthesia patients. Mild hypotension and decreased heart rate (HR) were the most common hemodynamic changes with spinal anesthesia, whereas hypertension and increased HR were the result of general anesthesia. Among spinal anesthetic drugs, plain bupivacaine was associated with the lowest incidence of supplemental local anesthetic use intraoperatively compared to hyperbaric bupivacaine or hyperbaric tetracaine. CONCLUSION Spinal anesthesia is an effective alternative to general anesthesia for lumbar spine surgery and has a reduced rate of minor complications.

Ischaemic optic neuropathy after spinal fusion.

PurposeWe report a case of ischaemic optic neuropathy which occurred after prolonged spine surgery in the prone position in an obese, diabetic patient.Clinical featuresThe patient was a 44-yr-old, 123 kg, 183 cm man for decompressive laminectomy and instrumented fusion of the lumbar spine. Anaesthesia was induced with thiopentone, fentanyl and succinylcholine and maintained with nitrous oxide, oxygen, isoflurane and a fentanyl infusion. He was positioned prone on the Relton-Hall frame and had an uneventful intraoperative course. Estimated blood loss was 3,000 ml. He was taken to the surgical intensive care unit (SICU) and the trachea was extubated 3.5 hr later. He had no pulmonary or haemodynamic problems and went to a regular nursing floor in the morning. He was discharged home on postoperative day #5. He telephoned his surgeon on postoperative day #7 to say that his vision had been blurry since surgery. His visual acuity was decreased, and on examination, he had a bilateral papillary defect, optic swelling and a splinter haemorrhage in the right eye. Magnetic resonance imaging (MRI) scan of the head and orbits detected no other abnormality. Based on this examination, he was felt to have bilateral ischaemic optic neuropathy and treated conservatively. By postoperative day #47, his visual acuity was greatly improved and near normal. Careful review of possible contributing factors suggests that the cause of the ischaemic optic neuropathy was venous engorgement.ConclusionThis patient developed ischaemic optic neuropathy from a prolonged interval in the prone position of the Relton-Hall frame, which may be related to venous engorgement.ObjectifNous rapportons un cas de neuropathie optique ischémique consécutive à une chirurgie rachidienne prolongée en décubitus ventral chez un obèse diabétique.Éléments cliniquesUn patient de 44 ans, pesant 123 kg et mesurant 183 cm était opéré pour une laminectomie décompressive avec ostéosynthèse instrumentale de la colonne lombaire. Le thiopental associé à du fentanyl et de la succinylcholine a servi à induire l’anesthésie, qui a été entretenue avec du protoxyde d’azote, de l’oxygène, de l’isoflurane et une perfusion de fentanyl. Il était immobilisé en décubitus ventral sur un cadre de Relton-Hall et l’opération s’est déroulée sans incident. On a estimé la perte sanguine à 3000 ml. Il a été transféré à l’unité des soins intensifs (USI) et extubé 3,5 h plus tard. Il ne présentait aucun problème respiratoire et hémodynamique et on l’a ramené dans son unité de soins le lendemain matin. Il était libéré le cinquième jour. Par téléphone, il avisait son chirurgien le septième jour que sa vision était embrouillée depuis l’intervention. Son acuité visuelle avait diminué et à l’examen, il présentait une lésion papillaire bilatérale, de l’oedème du nerf optique et une hémorragie linéaire de l’oeil droit. L’imagerie par résonance magnétique de la tête et des orbites ne montrait aucune autre anomalie. Cet examen suggérait une neuropathie optique ischémique bilatérale qui fut traitée de façon conservatrice. Le 47e jour postopératoire, son acuité visuelle s’était améliorée considérablement et était presque redevenue normale. Parmi les facteurs contributoires possibles cette neuropathie ischémique, il faut retenir l’engorgement veineux.ConclusionÀ la suite d’une immobilisation prolongée en décubitus ventral sur un cadre de Relton-Hall, ce patient a présenté une neuropathie optique par ischémie causée vraisemblablement par engorgement veineux.

A study of computer-assisted tomography II. Comparison of metrizamide myelography and computed tomography in the diagnosis of herniated lumbar disc and spinal stenosis

One hundred twenty-two patients with surgically confirmed pathology consisting of either herniated lumbar disc, spinal stenosis, or both were included in this investigation. For each of these patients, preoperative metrizamide myelography and computerized tomography were performed. Each myelogram and CT scan was read blindly so that the neuroradiologist interpreting the study had no knowledge of the patients surgical pathology, clinical examination, nor any knowledge of the interpretation of the other preoperative test. A painstaking attempt was made to describe precisely both the exact nature of the preoperative myelogram and CT scan interpretations. The correlations between the preoperative interpretation of each test and the observed surgical findings then were analyzed statistically. Based upon this analysis, myelography was found to be more accurate than computed tomography in the diagnosis of herniated lumbar disc (83% vs. 72%). In the diagnosis of spinal stenosis, myelography was slightly more accurate than computed tomography (93% vs. 89%). Based upon the results of this study, the authors conclude that metrizamide myelography is more accurate than computed tomography in the diagnosis of both herniated lumbar disc and spinal stenosis and remains the diagnostic study of choice for these conditions. Furthermore, metrizamide myelography gives the added advantage of visualizing the thoracolumbar junction and, thus, affords the opportunity to diagnose occult spinal tumors.

MRI diagnosis of tuberculous vertebral osteomyelitis

Two patients with suspected tuberculous spondylitis and one patient with previous Potts disease were evaluated preoperatively with magnetic resonance imaging (MRI). The MRI provided more exact anatomic localization of vertebral and paravertebral tuberculous abscesses in multiple planes not previously available with more conventional diagnostic methods in the patients with suspected tuberculous spondylitis. This was helpful for localization in planning of surgical approaches. In the patient with previous Potts disease, spinal cord compression was detected using MRI, which showed no evidence of active tuberculosis. Two case reports are offered to show the benefit of using MRI as a diagnostic technique in preoperative evaluation and as a method of monitoring treatment response of tuberculous spondylitis. The third case shows the benefit of using MRI to rule out active infection and to detect other forms of spinal pathology.

Complications associated with lumbar laminectomy: a comparison of spinal versus general anesthesia.

Study Design. A case-controlled, comparative study of 400 patients undergoing lumbar surgery, treated with either spinal or general anesthesia. An independent observer analyzed outcomes. Objectives. To determine the rate and type, of perioperative complications associated with each anesthetic method among lumbar surgery patients. Summary of Background Data. Spinal anesthesia is infrequently used for spinal procedures. While complications associated with spinal anesthesia are rare, some authors have suggested that spinal anesthesia may exacerbate existing neurologic disease and have recommended against its use in lumbar disc surgery. Others have found the technique safe and effective. General anesthesia may be preferred because it is seen as the routine accepted practice, because of greater patient acceptance and the ability to perform longer operations, or because of a general sense that general anesthesia is “safer” in these procedures. Methods. Patients treated between 1994 and 1998 were matched for anesthetic class, preoperative diagnosis, surgical procedure, and perioperative protocols. All patients were treated according to a uniform protocol and recovered in the same perianesthetic environment. Data from the intraoperative period through hospital discharge were collected and compared. Results. A total of 200 patients were included in each group. Overall complication rates and time to discharge were significantly lower in spinal anesthetic patients. Total anesthetic and operative times were significantly longer for general anesthetic patients, and perioperative heart rate and mean arterial pressures were elevated compared with those in spinal anesthetic patients. Nausea, requirements for antiemetic medication, and the incidence of urinary retention were significantly increased among general anesthesia patients. Spinal anesthesia patients had fewer spinal headaches compared with the general anesthetic group, but statistical significance was not obtained. Conclusions. For patients undergoing decompressive lumbar surgery, spinal anesthesia is at least comparable to general anesthetic with respect to complications. Specific advantages to spinal anesthesia include decreased nausea and antiemetic requirements, reduced analgesic requirements, and reduced overall complication rate.

Flexion-extension MRI of the upper rheumatoid cervical spine

Seven rheumatoid arthritis patients with involvement of the upper cervical spine were evaluated with a dynamic MRI study. Lateral T1 weighted images of the upper C-spine were obtained in the flexion, extension, and neutral positions. The indications for performing the dynamic MRI were radiographic instability of the upper C-spine, myelopathy, superior migration of the odontoid process, obliteration of bony landmarks on plain radiographs, and to determine the contribution of pannus on cord configuration. The dynamic MRI clearly delineated the relationship between the odontoid, foramen magnum, and cervical spinal cord as the neck was moved through a range of motion. This aided in the selection of operative candidates in four cases, and was instrumental in determining fusion levels. In three cases with suspected myelopathy secondary to cord impingement, MRI showed no significant cord compression, and aided in the decision to treat the patients conservatively. Lateral flexion-extension MRI is the diagnostic study of choice in dynamically evaluating the upper rheumatoid C-spine.

Cranial nerve palsy as a complication of operative traction

STUDY DESIGN Case report. OBJECTIVE This report documents one case of diplopia from abducens (sixth cranial) nerve palsy after spinal surgery using a Jackson table and cranial traction. SUMMARY OF BACKGROUND DATA Cranial nerve deficits have frequently been described in the orthopedic literature after trauma, halo pelvic traction, and halo skeletal fixation. The theorized mechanism of injury to the abducens nerve involves stretch or traction force, which causes localized ischemia or a change in nerve position. An extensive literature search failed to show this type of injury using Gardner-Wells tongs in conjunction with the Jackson table. METHODS This is a case report that included a chart review, examination of the patient, and a literature search. RESULTS The patient had complete spontaneous resolution of abducens nerve dysfunction within 6 months. CONCLUSIONS It is important for the surgeon to be aware of this potential complication and to inform patients who have diplopia that develops from abducens nerve palsy that most of these cranial nerve deficits spontaneously improve.

Massive bleeding during spine surgery in a patient with ankylosing spondylitis

PurposeAnkylosing spondylitis is associated with pathophysiology that has important anaesthetic implications. We report a case where the sequelae of ankylosing spondylitis may have been responsible for massive bleeding during emergency spine surgery.Clinical FeaturesA 69 yr old man with long standing ankylosing spondylitis sustained a complex fracture of the lumbar spine in a fall, and was scheduled for stabilization of the spine. Under general anaesthesia, prone positioning was difficult because of the extreme spinal deformity. During exploration, dilatation of epidural veins was encountered and sustained haemorrhage was encountered throughout,the surgical procedure. Estimated blood loss was 17,000 ml which was replaced with 31 units of packed red blood cells, 3200 ml of salvaged blood, 18 units of fresh frozen plasma, 26 units of platelets, 1,000 ml of albumin and 9,000 ml of crystalloid.ConclusionsExtreme deformity of the spine led to positioning difficulties that may have contributed to massive blood loss during complex spine surgery. Difficulties with placement in the prone position in-patients with advanced ankylosing spondylitis should be anticipated.RésuméObjectifLa spondylarthrite ankylosante est associée à la physiopathologie ayant d’importantes implications anesthésiques. Nous rapportons un cas où les séquelles de la spondylarthrite ankylosante peuvent avoir été responsables d’un saignement abondant pendant une chirurgie d’urgence de la colonne vertébrale.Aspects cliniquesUn homme de 69 ans, atteint de spondylarthrite ankylosante depuis longtemps, a subi lors d’une chute une fracture complexe de la colonne lombaire pour laquelle on a programmé une stabilisation. Pendant l’anesthésie générale, l’importante déformation de la colonne a compliqué l’installation en décubitus ventral. Lors de l’exploration, on a dû faire face à la dilatation des veines péridurales et à une hémorragie, qui s’est prolongée pendant toute la durée de l’intervention. La perte sanguine, estimée à 17 000 ml, a été compensée par 31 unités de globules rouges concentrés, 3 200 ml de sang récupéré, 18 unités de plasma frais congelé, 26 unités de plaquettes, 1000 ml d’albumine et 9 000 ml de cristalloïdes.ConclusionL’importante déformation de la colonne vertébrale a compliqué l’installation du patient, ce qui a pu contribuer à des pertes sanguines abondantes pendant une chirurgie complexe de la colonne. Des difficultés d’installation en décubitus ventral sont à prévoir avec un patient hospitalisé souffrant de spondylarthrite ankylosante avancée.

Influence of lumbar spine pathology on the incidence of paresthesia during spinal anesthesia

Background and Objectives. Paresthesia occasionally occurs during dural puncture or injection of local anesthetic for spinal anesthesia. Although the incidence of neurologic complications after spinal anesthesia is extremely low, the significance of paresthesia is unknown. The influence of known lumbar spine pathology on the incidence of paresthesia during spinal anesthesia is studied. Methods. Incidence of paresthesia with dural puncture (PP) or injection (PI) was studied in two groups of patients. Group 1 included patients for elective total joint replacement without known spine pathology or complaints. Group 2 included patients for elective lumbar spine surgery who received spinal anesthesia. Results. Significantly more PP (20% vs 9%) and PI (16% vs 6%) occurred in the spine surgery group. There were no neurologic sequelae of spinal anesthesia. Conclusions. This information suggests that the incidence of paresthesia during the conduct of spinal anesthesia is higher in patients with lumbar spine pathology. Although there were no neurologic complications, the sample size is too small to exclude an increase in the neurologic risk of spinal anesthesia in patients with known intraspinal pathology.

Effects of crystalloid versus colloid and the α-2 agonist brimonidine versus placebo on intraocular pressure during prone spine surgery: A factorial randomized trial

Background: Volume replacement with colloid solution and topical &agr;-2 agonists may each moderate the progressive increase in intraocular pressure (IOP) during prone surgery. The authors tested the hypotheses that during prolonged prone surgery, IOP increases less with goal-directed intravenous administration of 5% albumin than with goal-directed administration of lactated Ringers solution, and with topical &agr;-2 agonist brimonidine than with placebo eye drops. Methods: Patients having complex prone spine surgery were factorially randomized to albumin and topical placebo (n = 15); albumin and topical brimonidine (n = 16); lactated Ringers solution and topical placebo (n = 13); and lactated Ringers solution and topical brimonidine (n = 16). IOP was measured with a pneumotonometer. The primary outcome was time-weighted average intraoperative IOP. Results: Prone positioning increased IOP a mean ± SD of 12 ± 6 mmHg. IOP increased to 38 ± 10 mmHg at the end of anesthesia (approximately 5.5 h). Time- weighted average intraoperative IOP in the brimonidine group was 4 (95% CI: 1, 8) mmHg lower than in the placebo group (P = 0.023), but no different in the crystalloid and albumin groups (mean difference (95% CI) of −2 (−5, 2) mmHg (P = 0.34). There was no interaction between the two randomized factors. Conclusions: Brimonidine slightly reduced the primary outcome of intraoperative time-weighted average IOP, whereas there was no significant difference between goal-directed albumin or crystalloid administration. Brimonidine thus helps reduce IOP during spine surgery, but maintaining adequate blood pressure might play a more important role.