Comparison of methods of local anaesthesia used for cataract extraction

This paper will discuss the various techniques used for the instillation of local anaesthetics (LA) during intraocular (10) cataract extraction. It will be limited to a comparison of peribulbar block, sub-Tenons block and topical plus intracameral anaesthesia alone, as these are those most frequently used at the author's place of work. It will focus on both the surgeons' preferences and the patients' perceptions and comfort pre-, peri- and postoperatively. A description of each technique and the drugs available will be followed with a discussion of the patients' perceptions and pain levels. Included will be a summary of the patients' anxiety levels and the benefits of any sedation. Throughout, general and specific complications will be debated. All will be supported by current, relevant literature.

Randomized comparison of the single-injection volar subcutaneous block and the two-injection dorsal block for digital anesthesia

BACKGROUND

Two commonly used methods of digital nerve block with local anesthetic are the two-injection dorsal technique and the single-injection volar subcutaneous technique. The authors compared these two digital block techniques with respect to local anesthetic injection pain and recipient preference of anesthetic technique.

METHODS

Twenty-seven volunteers had the long finger of each hand injected with 2% lidocaine with 1:100,000 epinephrine. The two-injection dorsal method was used on one long finger and the other long finger received the volar single-injection technique. Volunteers completed a pain scale for each block and were then asked which technique they would prefer. The area of anesthetic skin was assessed in each finger by pinprick testing, and photographs were taken.

RESULTS

Although there was a lower pain score for the volar single-injection block, the difference in pain scores between the two techniques was not statistically significant. However, 22 of the 27 subjects indicated that they would select the volar over the dorsal block if a future block was required, and this preference for the volar block was statistically significant.

CONCLUSIONS

Although the difference in pain scores between the two techniques was not statistically significant, volunteers who received both blocks would prefer the volar single-injection subcutaneous block if given a choice. Therefore, the single-injection volar subcutaneous block is recommended as the technique of choice for anesthesia of the digit, except in patients for whom anesthesia over the dorsum of the proximal phalanx is required. These patients may prefer a supplementary dorsal nerve block or a traditional two-injection block.

Assessment of a palatal approach-anterior superior alveolar (P-ASA) nerve block with the Wand in paediatric dental patients

OBJECTIVES

The purposes of the study were to compare the reaction of children while receiving local anaesthesia for anaesthetizing maxillary incisors with a computerized device Wand: a periodontal ligament injection (PDLi) and a palatal approach-anterior superior alveolar (P-ASA) nerve block compared with a conventional buccal infiltration (CBi), and to assess the efficacy of the anaesthesia and children's reaction after treatment.

METHODS

One hundred and thirty-eight children aged 24-48 months participated in this study.

RESULTS

More children reacted negatively during injection while receiving the CBi and positively during the injection with the Wand. After treatment, significantly more children scratched the upper lip and/or the nose or complained of numbness of the region after the CBi (P = 0.000).

CONCLUSIONS

Same effectiveness was achieved with the Wand and the CBi. Children displayed better behaviour during injection when they received local anaesthesia with the WanD than they did when the CBi was used. They did not scratch the upper lip/nose and/or cried after treatment when they received the PDLi and the P-ASA, whereas they did when receiving a CBi.

Bradycardia and hypertension in anticipation of, and exacerbated by, peribulbar block: a prospective audit

BACKGROUND

Changes in heart rate (HR), systolic arterial pressure (SAP) and diastolic arterial pressure (DAP) occur in anticipation of, and following, injection of a peribulbar local analgesic agent. We examined these changes in two groups of awake patients given a pre-medication of either hydroxyzine 1.0 mg/kg alone (control) or hydroxyzine 1.0 mg/kg with morphine 0.05 mg/kg.

METHODS

HR, SAP and DAP of 100 patients per group were monitored the day before surgery (baseline), every 5 min in the anesthesia holding room before peribulbar injection, every minute for the first 5 min after peribulbar injection and then every 5 min until transfer to the operating room. Within and between pre-medication group values of HR, SAP and DAP before and after peribulbar injection were compared with baseline.

RESULTS

The two groups of patients were similar. Before peribulbar injection, HR was unchanged in the hydroxyzine group, but 6% slower in those given morphine (P<0.01). After injection, HR slowed in both groups, by 5% and 7% (P<0.01, both comparisons), respectively. In anticipation of injection, SAP increased in both groups to 20% and 16% above baseline, respectively, and increased further after injection to 26% and 24% above baseline, respectively (P<0.001, all comparisons). In both groups, maximum SAP following injection exceeded maximum SAP before injection (P<0.02, both comparisons). DAP increased by 4% (P<0.05) in the hydroxyzine group before injection, and by 5% and 4%, respectively (P<0.005 and P<0.05, respectively) after peribulbar injection.

CONCLUSION

The audit reveals pronounced increases in SAP accompanied by lesser increases in DAP and a tendency to slowing of HR in awake patients in anticipation of peribulbar injections. Peribulbar injections cause further increases in blood pressure and mild bradycardia. These changes occur similarly in patients pre-medicated with hydroxyzine or hydroxyzine plus morphine. A mix of neuro-humoral influences (anxiety/catecholamine/baroreceptor/trigemino-vagal) are postulated as etiological.

Danish dentists' knowledge, attitudes and management of procedural dental pain in children: association with demographic characteristics, structural factors, perceived stress during the administration of local analgesia and their tolerance towards pain

OBJECTIVE

The aim of the present study was to describe Danish dentists' knowledge of, attitudes towards and management of procedural pain during paediatric dental care, and to assess the importance of demographic characteristics, structural factors, perceived stress during administration of local analgesia and the dentists' own tolerance towards procedural dental pain.

DESIGN

A cross-sectional questionnaire study was conducted in Denmark in May 2001.

SUBJECTS AND METHODS

The subjects were a random sample of 30% of Danish dentists treating children. Usable information was obtained from 327 (80.3%) of the dentists in the sample.

RESULTS

One-quarter of the respondents answered that a 3-5-year-old child could report pain only with uncertainty. More than 80% of the dentists stated that they never compromised on painlessness. Very few agreed to the statement that children forget pain faster than adults. One-third agreed to, or were neutral to, the statement that all restorative care in primary teeth could be performed painlessly using N2O-O2 sedation alone. The majority of the respondents reported using three or more methods to assess the effect of their pain control methods. Almost 90% reported using local analgesia for restorative work 'always' or 'often'. A similar proportion reported using topical analgesia before injection 'always' or 'often'. Administering a mandibular block to preschool children was the procedure perceived as the most stressful (33.6%) pain control method. Demographic factors (gender), structural factors (always working alone and treating 3-5-year-old children daily), perceived stress during the administration of a mandibular block in preschool children and the dentists' own willingness to accept potentially painful dental treatment without local analgesia were associated with knowledge of, attitudes towards and management of procedural dental pain in children.

CONCLUSIONS

Danish dentists treating children demonstrate concern about procedural dental pain in children. Factors amenable to change via training and reorganization into larger clinical units seem to determine their knowledge of, attitudes towards and management of procedural dental pain in children.

Analgesia and effectiveness of levobupivacaine compared with ropivacaine in patients undergoing an axillary brachial plexus block

A common anesthetic technique for the upper extremity is local brachial plexus anesthesia using levobupivacaine and ropivacaine. To our knowledge, no study has been performed measuring differences in analgesic efficacy and latency when these local anesthetics are used for brachial plexus anesthesia. We enrolled 54 adults, assessed as ASA class I or II, into this double-blind, prospective investigation to receive 40 mL of 0.5% ropivacaine or levobupivacaine with 1:200,000 epinephrine. Pain was assessed using a 0 to 10 verbal numeric rating scale (VNRS). Motor blockade was determined using a modified Bromage scale. Variables included analgesic duration, latency, and overall patient satisfaction. The ropivacaine group had significantly higher VNRS scores at the 8th (P= .001) and 10th (P = .003) postoperative hours. The duration of sensory analgesia was significantly longer in the levobupivacaine group (831 minutes) than in the ropivacaine group (642 minutes, P = .013). Return of motor activity was significantly faster in the ropivacaine group (778 minutes) than in the levobupivacaine group (1,047 minutes; P = .001). No other significant differences were noted between the groups. When considering levobupivacaine and ropivacaine for brachial plexus anesthesia, levobupivacaine should be considered when postoperative analgesia is a concern but not when an early return of motor activity is required.

The addition of clonidine to bupivacaine in combined femoral-sciatic nerve block for anterior cruciate ligament reconstruction

Clonidine has been shown to prolong sensory analgesia when given as an adjunct to peripheral nerve blocks but has not been evaluated when given in conjunction with a femoral-sciatic nerve block. The purpose of this investigation was to determine whether the addition of clonidine to a femoral-sciatic nerve block would prolong the duration of sensory analgesia in groups of patients undergoing anterior cruciate ligament (ACL) reconstruction. This prospective, randomized, double-blind investigation was performed on 64 subjects undergoing ACL reconstruction. Patients were assigned randomly to receive a femoral-sciatic nerve block using 30 mL of 0.5% bupivacaine with 1:200,000 epinephrine (control group) or 30 mL of 0.5% bupivacaine with 1:200,000 epinephrine and 1 microg/kg of clonidine (experimental group). Variables measured included demographics, timed pain intensity measurements, postoperative analgesic consumption, duration of analgesia, and patient satisfaction. No significant differences were noted between groups for pain intensity scores, duration of sensory analgesia, postoperative analgesic requirements, or overall patient satisfaction. Both groups reported minimal amounts of postoperative pain and high analgesic satisfaction scores. Based on our results, we do not recommend the addition of clonidine to a femoral-sciatic nerve block when given to facilitate postoperative analgesia in patients undergoing ACL reconstruction.

Therapeutic selective nerve root block in the nonsurgical treatment of traumatically induced cervical spondylotic radicular pain

OBJECTIVE

To investigate the outcomes resulting from the use of fluoroscopically guided therapeutic selective nerve root block in the nonsurgical treatment of traumatically induced cervical spondylotic radicular pain.

DESIGN

Retrospective study with independent clinical review. A total of 15 patients who met specific physical examination or electrodiagnostic criteria and failed to improve clinically after at least 4 wks of physical therapy were included. Each patient demonstrated a positive response to a fluoroscopically guided cervical selective nerve root block. Therapeutic selective nerve root blocks were administered in conjunction with physical therapy. Outcome measures included visual analog scale pain scores, employment status, medication usage, and patient satisfaction.

RESULTS

Patients' symptom duration before diagnostic injection averaged 13.0 mos. An average of 3.7 therapeutic injections were administered. Follow-up data collection transpired at an average of 20.7 mos after discharge from treatment. An overall good or excellent outcome was observed in three patients (20.0%). Among those treated without surgery, a significant reduction (P = 0.0313) in pain score was observed at the time of follow-up. Six patients (40.0%) proceeded to surgery.

CONCLUSIONS

These initial and preliminary findings do not support the use of therapeutic selective nerve root block in the treatment of this challenging patient population with traumatically induced spondylotic radicular pain.

Patients' experiences with multiple stimulation axillary block for fast-track ambulatory hand surgery

BACKGROUND

Ambulatory axillary block by multiple nerve stimulation (MNS) is effective and time efficient, but may be rejected by patients because of block pain. This prospective study assessed patients' anxiety and acceptance of this block, identified which of the components of blocking procedure is most painful (i.v. line insertion, repeated needle passes, local anesthetic injection, or electrical stimulation) and recorded patients' anesthetic preferences for the future hand surgery.

METHODS

Upon arrival at the day unit, 100 unpremedicated adult patients without previous experience of peripheral nerve stimulation indicated on the visual analog scale (VAS; 0-100) their anxiety about the block. The blocking procedure was then explained step-by-step. After inserting the i.v. line and freezing the skin in axilla, four terminal nerves (musculocutaneous, median, ulnar, radial) were electrolocated using an initial current of 2 mA and a target current of 0.1-0.5 mA. Pain caused by the individual components of blocking procedure was assessed on VAS before the start of surgery. On the day after the operation, the patients reassessed their anxiety for the next axillary block and indicated which anesthetic method (block alone, block plus sedation, or general anesthesia) they would prefer for the future hand surgery.

RESULTS

Before the block, 59 patients admitted being anxious about regional block (median anxiety VAS=27), compared with 42 patients (anxiety VAS=10) postoperatively: P<0.01. Median intensity of electrical stimulation pain was significantly higher (VAS=16) than pain of local anesthetic injections (VAS=8), i.v. line insertion (VAS=6) and multiple needle passes (VAS=5). However, only 53 patients categorized electrolocation as painful. Twenty-seven reported discomfort but not pain, and 20 patients described the sensation as 'funny' or 'strange'. None of the patients had surgical pain during operation. Mean duration of surgery was 77 min, and of hospital stay 166 min. Ninety-eight patients would choose the same block for the future hand surgery, 13 of which would like sedation before the block, and two patients did not wish to be awake during any surgery. Ninety-five patients were satisfied with fast-tracking.

CONCLUSIONS

Fear of block pain is diminished after experiencing the blocking procedure. Electrical stimuli was perceived as painful by 53% of patients, and this pain was more intense than with other block components. The majority of our patients would choose axillary block without sedation for future hand surgery and are satisfied with fast-tracking.

Gray ramus communicans nerve block: novel treatment approach for painful osteoporotic vertebral compression fracture

BACKGROUND

Osteoporotic vertebral compression fracture (OVCF) is a common complication of osteoporosis in the aging population. Refractory chronic pain may develop, and few effective treatment options exist.

METHODS

We retrospectively analyzed 52 cases in which gray ramus communicans nerve block was used for painful OVCF after failure of conservative analgesic therapy. All were office-based, fluoroscopically guided procedures; a combination of 2% lidocaine and 2% sterile triamcinolone diacetate (Aristocort) was injected on the gray ramus tract of the somatic nerve root corresponding with radiographically documented OVCF. Patient-reported and physician-reported pain scores, analgesic medication use, and overall patient satisfaction were measured. The average follow-up period was 9 months.

RESULTS

A 1-point improvement in pain scores was reported by 92% of patients and 88% of physicians; a 4-point improvement was reported by 63% and 58%, respectively. No patients reported increased pain scores; physicians reported increases in two cases. Decreased analgesic requirement was documented in 42%. Patient satisfaction was "high" in 50% and "medium" in 25%. No procedural complications occurred.

CONCLUSION

Prompt and sustained improvements in all parameters, especially pain scores, support widespread clinical application of this safe effective and cost-effective therapy.

Influence of neuroticism, catastrophizing, pain duration, and receipt of compensation on short-term response to nerve block treatment for chronic back pain

This study investigated the influence of pain catastrophizing, neuroticism, pain duration, and receipt of compensation for 60 patients undergoing nerve block treatment for chronic back pain. Follow-up assessment 1 week following nerve block treatment found that neither neuroticism nor catastrophizing predicted level of reported pain or extent of disability. However, receipt of compensation and duration of pain were both associated with reduced benefit from treatment. The above four variables combined were able to account for 24% of the outcome variance in both level of pain and extent of disability. Possible causal patterns related to compensation and treatment outcome, limitations of the study, and directions for future research are discussed.

Mandibular block injections--the inner game

This paper is a sequel to a previous article published in the April 1998 issue of this journal (1). Whereas the earlier work concentrated largely on the anatomy and geometry of the Gow-Gates block, the present paper is more directed towards the mental barriers encountered when a clinician is confronted by a whole new set of conceptual demands. Paradoxically, the concepts underlying the Gow-Gates technique are almost diametrically opposite to what has traditionally been taught in dental schools in relation to the inferior alveolar nerve block. The author's central hypothesis is that the explanation for indifferent results experienced by dentists in their first attempts at the Gow-Gates technique lies primarily in mindsets acquired from experience with the inferior alveolar block. It is suggested that the subconscious mind can be as powerful a determinant of human behaviour as the conscious mind, a position more in line with the findings of Freud and Jung than with the cognitivist vogue enthusiastically embraced by contemporary academic psychologists. It is further postulated that the subconscious is amenable to conscious guidance, a skill that can be enhanced by practice.

The use of stop signals to reduce the pain and distress of patients undergoing a stressful medical procedure: an exploratory clinical study

The present study investigates stop signals and their effects on the pain and distress of patients undergoing a stressful medical procedure. Thirty-six chronic pain patients (17 men, 19 women) attending an out-patient operating theatre for diagnostic nerve blocks/local anaesthetic injections were allocated to one of two conditions (experimental and control). All patients received a standard information leaflet concerning the forthcoming injections. Additional information was given to those in the experimental group on four occasions (three orally, one written) before the injections which stated that they could halt the procedure at any time by saying 'stop'. Subjective measures of anxiety, pain, distress, sense of control over the procedure as well as observer ratings of patient distress and pain behaviour were obtained before, during and after the injections. After initial differences in pre-injection pain were controlled for the experimental group, patients rated themselves as less distressed during the injections and recorded lower state anxiety following treatment. In view of various methodological limitations of the present study its findings may only be accorded 'pilot study' status. These limitations are explored in the discussion along with their implications for a more robust replication study. Nevertheless the present findings provide tentative support for the hypothesis that the use of stop signals can reduce the stressful nature of diagnostic nerve blocks.

Evaluation of lidocaine and tetracaine mixture in axillary brachial plexus block

The mixture of 1% lidocaine and 0.2% tetracaine with 1:200,000 epinephrine, so-called "supercaine," has been used extensively for axillary brachial plexus blockade for several decades. Since the advent of bupivacaine, the supercaine mixture has fallen into relative disuse despite its record of effectiveness and safety. No studies have been done recently to evaluate quality of anesthesia, duration of postoperative analgesia, and degree of patient satisfaction with this mixture when used for axillary brachial plexus blockade. The assumptions were as follows: surgical anesthesia will be adequate, length of postoperative analgesia will be approximately 4 to 9 hours, and patients will be highly satisfied. The specific aim of the present study was to describe the anesthetic characteristics of supercaine. Patients between 18 and 65 years of age received a standard mixture of supercaine, totaling 450-500 mg of lidocaine and 90 to 100 mg of tetracaine. Epinephrine in a solution of 1:200,000 and an 8.4% solution of sodium bicarbonate were added, and the transarterial technique was used. Patients were contacted on postoperative day 1 to determine the duration of sensory and motor block; overall satisfaction with the block was rated. Data were analyzed with the Statistical Program for the Social Sciences (SPSS, Chicago, Ill) and Stata (Stata Corp., College Station, Tex) computer programs. The mean +/- SD findings were as follows: duration of sensory block, 465 +/- 204 minutes; duration of motor block, 473 +/- 214 minutes; patient satisfaction score, 9 +/- 1 on a 1 to 10 scale. Data are reported within a 95% confidence interval. Variables examined and compared were not statistically significant. We concluded that the duration of block supports findings reported in the literature, patients equate duration of sensory block with duration of motor block, differences in duration were probably due to levels of provider experience, and patients were extremely satisfied with the anesthetic.

Local infiltration and spermatic cord block for inguinal, scrotal and testicular surgery

This was a prospective study involving 372 male patients. Surgical procedures including simple inguinal hernia repair, inguinal lymph node biopsy, hydrocelectomy, testicular biopsy, testicular fixation, orchidectomy and scrotal exploration were performed under local anaesthesia using various quantities of 0.5% xylocaine with adrenaline depending on the procedure, in the form of spermatic cord block and local infiltration nerve blocks. No premedication was given to any patient and only five patients (1.34%) were given intraoperative sedation due to anxiety. No complication directly attributed to the anaesthetic agent used or the technique of spermatic cord and nerve blocks were reported during the study. Three hundred and sixty patients (96.77%) were operated on as outpatients and were happy and satisfied to return home on the same day. This experience confirms that spermatic cord block accompanied by local infiltration with 0.5% xylocaine with adrenaline is simple, safe and effective technique that should be used more widely in outpatient urological and general surgical settings in this locality. It provides excellent intra-scrotal and inguinal anaesthesia. Furthermore, the technique is cost effective, and personnel effective since no anaesthetist is required for the procedure which is usually carried out by the surgeon. This would enable many more people to afford the surgical procedures.

Dentists troubled by the administration of anesthetic injections: long-term stresses and effects

A questionnaire was mailed to 3,000 practicing dentists to inquire about their physical and psychological responses to the task of administering local anesthesia. Surprisingly, 18.8% of the 711 responding dentists reported that the administration of injections causes them enough distress to have (at least at some time) reconsidered dentistry as a career. Six percent of respondents considered their thoughts and feelings to be a serious problem, whereas only 2% reported no negative reactions to this aspect of clinical practice. Self-reported reactions to various anesthetic procedures were compared, and the various responses are discussed. It is concluded that the administration of anesthetic injections is a rarely discussed but significant contributor to the overall professional stress and difficulty for many, but not all, dentists.