An anatomical study of the human lumbar ligamentum flavum

Objectives: A detailed investigation of the gross and microscopic anatomy of ligamentum flavum. Methods: Material included 14 lumbar vertebral columns obtained from the Anatomy Department, King Faisal University, Dammam during the period between January 2005 and January 2006. Height, width, and thickness of ligamenta flava were measured. A microscopic study was also performed. Computed tomography scan was carried out on the lumbar vertebrae of 30 patients for measuring the ligamentum flavum. Results: The anatomical results showed that the right and left ligamenta flava join in the midline forming an acute angle with a ventral opening. The ligamentum flavum is rectangular and has 4 borders and 2 surfaces. It is attached inferiorly to the superior edge and the postero-superior surface of the lamina below. It is attached superiorly to the inferior edge and the antero-inferior surface of the lamina above. Its height ranges from 14-22 mm. The width of its lower part ranges from 11-23 mm, and the thickness ranges from 3.5-6 mm. The histological results revealed that it is comprised chiefly of elastic fibres and some collagen fibres. Conclusion: The information reported in this study is of clinical value in the practice of lumbar epidural anesthesia or analgesia. Epidural puncture will be best performed through the lower and medial portion of the ligamentum flavum slightly lateral to the midline.

Neostigmine antagonism of rocuronium block during anesthesia with sevoflurane, isoflurane or propofol

Purpose: To examine the influence of continuing administration of sevoflurane or isoflurane during reversal of rocuronium induced neuromuscular block with neostigmine. Methods: One hundred and twenty patients, divided into three equal groups, were randomly allocated to maintenance of anesthesia with sevoflurane, isoflurane or propofol. Neuromuscular block was induced with rocuronium and monitored using train-of-four (TOF) stimulation of the ulnar nerve and recording the force of contraction of the adductor pollicis muscle. Neostigmine was administered when the first response in TOF had recovered to 25%. At this time the volatile agent administration was stopped or propofol dosage reduced in half the patients in each group (n = 20 in each group). The times to attain TOF ratio of 0.8, and the number of patients attaining this end point within 15 min were recorded. Results: The times (mean ± SD) to recovery of the TOF ratio to 0.8 were 12.0 ± 5.5 and 6.8 ± 2.3 min in the sevoflurane continued and sevoflurane stopped groups, 9.0 ± 8.3 and 5.5 ± 3.0 min in the isoflurane continued and isoflurane stopped groups, and 5.2 ± 2.8 and 4.7 ±1.5 min in the propofol continued and propofol stopped groups (P <0.5- 01). Only 9 and 15 patients in the sevoflurane and isoflurane continued groups respectively had attained a TOF ratio of 0.8 within 15 min (P <0.001 for sevoflurane). Conclusions: The continued administration of sevoflurane, and to a smaller extent isoflurane, results in delay in attaining adequate antagonism of rocuronium induced neuromuscular block.

INCIDENCE AND CLINICAL IMPORTANCE OF PERIOPERATIVE HISTAMINE-RELEASE - RANDOMIZED STUDY OF VOLUME LOADING AND ANTIHISTAMINES AFTER INDUCTION OF ANESTHESIA

Although histamine release is recognised as a common event during anaesthesia and surgery, few clinicians judge the resultant cardiorespiratory disturbances serious enough to warrant prophylaxis with antihistamines. We have assessed the incidence and importance of histamine release in a randomised 2 x 2 factorial study.

Ocular anesthesia in the new millennium

In the new millennium anesthetic agents will be safer and more efficient. Topical anesthesia will be the most frequently used technique. Time- and cost-saving measures will expand the current trend of outpatient surgery and anesthesia will be reduced. Patients' perioperative comfort will improve.

Subconjunctival versus peribulbar anesthesia in trabeculectomy:A prospective, randomized study

BACKGROUND AND OBJECTIVE: To compare the use of subconjunctival and peribulbar anesthesia for trabeculectomy. PATIENTS AND METHODS: Sixty patients undergoing trabeculectomy were prospectively randomized to receive either peribulbar or subconjunctival anesthesia. Peribulbar anesthesia consisted of a 3-ml inferior and a 1-ml superior injection of a 1:1 mixture of 2% mepivacaine, 0.75% bupivacaine, and hyaluronidase. Subconjunctival anesthesia consisted of a 1- to 2-ml injection of the same mixture without hyaluronidase in the superotemporal quadrant. Intraoperative pain, presence of eye movements, and complications during surgery were evaluated. RESULTS: The frequency and intensity of pain was statistically similar between the two groups. All episodes of pain (20% in the subconjunctival group and 6.6% in the peribulbar group) were rated as mild. Eye movement was more common in the subconjunctival group than in the peribulbar group, but it was controlled by verbal command and did not interfere with the procedure. No clinically significant complications occurred during surgery. CONCLUSION: Subconjunctival anesthesia is an effective alternative to peribulbar anesthesia for trabeculectomy.

Preliminary clinical assessment of polyvinyl alcohol-tetrahydroxyborate hydrogels as potential topical formulations for local anesthesia of lacerations

The aim of this study was to assess a novel semisolid material as a potential topical drug delivery system for acute laceration. The objectives were to correlate physical characterization data using rheologic studies and to compare with clinical assessment of performance in an emergency department (ED).

A Non-Inferiority Randomized Controlled Trial Comparing the Clinical Effectiveness of Anesthesia Obtained by Application of a Novel Topical Anesthetic Putty With the Infiltration of Lidocaine for the Treatment of Lacerations in the Emergency Department

We test the hypothesis that anesthesia, measured as pain scores, induced by a novel topical anesthetic putty is non-inferior (margin=1.3) to that provided by conventional lidocaine infiltration for the repair of lacerations.

The effects of sevoflurane and ketamine on intraocular pressure in children during examination under anesthesia

PURPOSE: We studied the effects on intraocular pressure (IOP) of anesthesia administered during examination under anesthesia (EUA) in children. DESIGN: Randomized clinical trial. METHODS: This randomized trial compared IOP after inhaled sevoflurane gas to that after intramuscular ketamine hydrochloride in children undergoing EUA. IOP was measured in 30 eyes with TonoPen XL (Mentor, Inc, Norwell, Massachusetts, USA) as soon as possible after anesthesia induction (T1) and two, four, six, and eight minutes thereafter. At the same times, we recorded systolic and diastolic blood pressure (SBP, DBP) and heart rate (HR). RESULTS: Compared with the mean IOP at T1, IOP in the sevoflurane group was significantly lower for all measurements from two to eight minutes thereafter (mean decrease in IOP: two minutes = 12%, four minutes = 19%; six minutes = 19%; eight minutes = 17%, all P < or = .01). In the ketamine group, mean IOP was not significantly changed from T1 through six minutes, whereas at eight minutes, it was 7% lower (P = .03). SBP and DBP were significantly lower for sevoflurane than for ketamine at all measurements from two minutes onward, and HR was lower for sevoflurane than for ketamine at two, four, and six minutes. CONCLUSIONS: IOP measured after ketamine sedation is more likely to represent the awake IOP than that after sevoflurane anesthesia. Changes in SBP, DBP, and HR caused by sevoflurane suggest that hemodynamic alterations may underlie its effects on IOP.