Lymphangioma in the metacarpal pad of a dog

OBJECTIVES: To estimate odontogenic bacteraemia following three different types of local anaesthetic injections, namely: buccal infiltration analgesia (BIA), conventional intraligamental analgesia (CIA), and modified intraligamental analgesia (MIA). PATIENTS AND METHODS: The bacteraemia-producing potential of three methods of injecting local analgesic solution was determined by taking blood samples, using aseptic technique, from 143 children, aged 1 year 11 months to 19 years 4 months, undergoing general anaesthesia for dental extractions. Of these 143 children, a subgroup of 50 had blood taken before any dentogingival manipulative procedures to provide a baseline level of bacteraemia. The injection methods were buccal infiltration, conventional intraligamental, and a modified intraligamental. The blood samples were taken 30 seconds after injection and cultured in aerobic and anaerobic broth cultures (Bactec) and from lysis filtration vials (Isolator). RESULTS: The percentage prevalence of bacteraemia was: baseline level 8%; buccal infiltration analgesia 16%; modified intraligamental analgesia 50%; and conventional intraligamental analgesia 97%. These values were statistically significantly different using the chi-squared test (P < 0.001). The mean value for colony forming units per millilitre (Isolator system) was 252 (sd = 646) for the intraligamental technique but zero for baseline, infiltration and modified intraligamental techniques. CONCLUSIONS: All local anaesthetic techniques studied were associated with bacteraemia which may have implications for antibiotic prophylaxis for dental treatment. The intraligamental techniques had statistically significantly greater percentage prevalence of bacteraemia compared with baseline. The modified intraligamental technique causes significantly less bacteraemia than the conventional intraligamental technique.     

Euthanasia and palliative care--an uneasy partnership

PURPOSE: To compare the effectiveness of the intraligamentary technique of anesthetic administration (ILA) with the inferior alveolar nerve block (IANB) in extraction of mandibular teeth. MATERIALS AND METHODS: ILA and IANB injections using Citanest with Octapressin were administered on 16 patients requiring bilateral mandibular dental extractions. Discomfort during needle placement, profoundness of anesthesia obtained, and patient preference were evaluated for both techniques. RESULTS: A total of 45 teeth were extracted. Ten patients (62.5%) reported discomfort during needle placement with ILA injection compared to three patients (18.75%) with IANB (P = 0.031). Fifty percent (12/24) of teeth extracted with ILA injection were removed without discomfort to the patient compared to 85.7% (18/21) using IANB (P = 0.027). No difference in patient preference between the two techniques was noted.     

A comparison of topical anaesthesia and electronic nerve stimulation for reducing the pain of intra-oral injections

This paper describes a model for investigating the efficacy of different methods of alleviating the pain of intra-oral injections. The efficacies of the topical anaesthetic EMLA cream and electronic nerve stimulation as means of reducing the discomfort of palatal injections prior to the extraction of maxillary teeth were investigated using the model in one hundred patients. EMLA reduced the pain of injection compared with placebo (P < 0.05) whereas the pain reported after electronic nerve stimulation did not differ significantly from placebo. It is concluded that EMLA is useful in reducing the pain of palatal injections.     

Sub-Tenon's anaesthesia: an efficient and safe technique

AIM: To evaluate sub-Tenon's anaesthesia as an alternative to peribulbar anaesthesia. METHODS: 109 consecutive patients listed for various eye operations (including cataract, trabeculectomy, and vitrectomy) under peribulbar anaesthesia were operated on under sub-Tenon's anaesthesia instead. After topical anaesthesia a buttonhole was fashioned through the conjunctiva and Tenon's capsule 10 mm posterior to the limbus. 1.5 ml of lignocaine 2% was then delivered to the posterior sub-Tenon's space using a blunt cannula. The surgical procedure was performed immediately after the completion of the anaesthetic procedure. Chemosis, conjunctival haemorrhage, degree of akinesia, and pain scoring were analysed. RESULTS: There were no anaesthesia related complications. The administration of the block was painless for 99.1% of the patients. In all, 97.3% reported no pain during surgery. There was no akinesia when assessed just after the completion of the block and akinesia was limited when assessed after surgery. Chemosis and conjunctival haemorrhage were frequent but caused no intraoperative problems. CONCLUSION: Sub-Tenon's anaesthesia is an efficient and safe anaesthetic technique. It is a good alternative to peribulbar anaesthesia.     

The efficacy of local anaesthetics administered by general dental practitioners

AIM: To obtain empirical evidence for the efficacy of local anaesthesia in dentistry. DESIGN: Retrospective analysis of serial administrations of local anaesthesia. METHODS: Dentist and patient evaluations of the success of differing techniques (infiltration and block) of anaesthesia in a variety of general practice procedures. Results were analysed for correlation between dentist and patient using a 5-point scale. RESULTS: Complete data were analysed for 331 administrations. In the hands of experienced dentists over 93% of operations were assessed by both dentist and patient as comfortable or completely comfortable. Dentists were generally able to judge patient comfort (P < 0.001). Administrations requiring repeat injections were less comfortable. Dentists judged infiltration administrations more comfortable than block administrations (P < 0.001), but patient judgements of comfort failed to distinguish between differing techniques at the P < 0.05 level. CONCLUSIONS: Some variations in success rate exist between dentists the most dental procedures under local anaesthetic in general practice were assessed as being comfortable or better by both dentists and patients.     

The risks of anesthesia in obstetric interventions

In obstetric anaesthesia, general anaesthesia combined with endotracheal intubation, spinal anaesthesia and peridural anaesthesia is used. The main risks of general anaesthesia are: difficult intubation, aspiration of acid gastric content in non-fasting patients, depression of the fetus with narcotics and the occurrence of awareness of the mother. The main dangers of spinal anaesthesia are: hypotension of the mother leading to reduced utero-placentar blood flow due to sympathetic block, post-spinal headache and vomiting. The specific risks of peridural anaesthesia are: maternal hypotension, the possibility of inadvertent intravenous injection of local anaesthetics leading to cardiac and cerebral intoxication, inadvertent intrathecal application of local anaesthetics followed by total spinal block which requires reanimation and inadvertent dura perforation followed by long-lasting headache. Most anaesthesia-related maternal deaths by far occur during Caesarean section performed under general anaesthesia, but at present there is no clear evidence that the anaesthetic risk of spinal or peridural anaesthesia, on the one hand, is lower than that one of general anaesthesia, on the other.     

Comparison of assisted reproductive technology performance after oocyte retrieval under general anaesthesia (propofol) versus paracervical local anaesthetic block: a case-controlled study

Propofol (Dipirivan) is an intravenous anaesthetic drug used for general anaesthesia. Although frequently used as a general anaesthetic for ultrasound procedures, its use during transvaginal oocyte retrieval is currently being debated. A total of 202 patients undergoing fertility treatment was included in a prospective, matched, controlled study, in which we compared fertilization rates and embryo development in terms of morphological quality and speed of development and the implications for reproductive outcome and pregnancy following general anaesthesia using either propofol or a paracervical local anaesthetic block during oocyte collection. There were no differences between the fertilization rates and the embryo cleavage characteristics for the two groups. The initial implantation rate per transferred embryo after general anaesthesia was similar to that after paracervical local anaesthetic block (13.4 versus 18.6%; P = 0.10). The ongoing clinical implantation rates per embryo transferred were also similar in the two groups.     

Long-term bone marrow culture profiles in patients with myelodysplastic syndromes are not explicable by defective apoptosis

PURPOSE: To compare intraoperative anaesthetic and haemodynamic effects of clonidine-bupivacaine, morphine-bupivacaine and placebo-bupivacaine combinations during continuous spinal anaesthesia. METHODS: Thirty six geriatric patients, undergoing knee replacement using continuous spinal anaesthesia were randomly assigned to: Placebo (n = 12), clonidine (n = 12) and morphine (n = 12), where 1 ml saline, 0.15 mg clonidine or 0.15 mg morphine were mixed with 10 mg bupivacaine 0.5%. Anaesthetic variables studied were maximal sensory level and degree of motor block, duration of surgical analgesia and duration of anaesthesia. Changes in systolic arterial pressure and vasopressor requirements were evaluated. RESULTS: Maximal sensory level and degree of motor block were comparable among the groups. Before surgery two patients in the placebo group, three in the clonidine and one in the morphine group received one additional ml bupivacaine 0.5% because of inadequate anaesthesia and were not considered for determination of duration of surgical analgesia. In the remainder, 1/9 in the clonidine group, 8/10 in placebo and 8/11 in morphine (P < 0.05) received reinjection of bupivacaine for surgical pain. These injections were given about 2 1/2 hr after the initial intrathecal injection, the duration of anaesthesia being about four hours. During the first 30 min after the initial injection the decrease in systolic pressure was greater in the clonidine and morphine than in the placebo group (P < 0.05). Thereafter, vasopressor requirements were higher only in the clonidine group (P < 0.05). CONCLUSION: In elderly patients 0.15 mg clonidine but not 0.15 mg morphine prolonged surgical analgesia when added to 10 mg plain bupivacaine.     

Detection of intravascular injection of regional anaesthetics in children

PURPOSE: Detection of intravascular injection of local anaesthetic during placement of regional blocks in children by using epinephrine-induced tachycardia or hypertension may produce false positive and false negative findings. This study evaluates ECG changes as markers of intravascular injection of local anaesthetics with epinephrine, during placement of epidural blocks in children. METHODS: Observational study in a teaching hospital of all epidural anaesthetics administered to paediatric patients during one year. General anaesthesia, where used, was not controlled. An ECG rhythm strip was recorded during test dose injection and analyzed for changes in rate, rhythm, and T-wave configuration. RESULTS: During the study period, 742 paediatric epidural blocks were administered. There were 644 caudal (284 without catheters), 97 lumbar, and one thoracic epidural anaesthetics. Satisfactory placement was achieved in 97.7% of patients. Intravascular injection was detected in 42 (5.6%) of epidural anaesthetics (3.8% and 6.7% of straight needle and catheter injections, respectively). Detection was by immediate aspiration of blood in six patients, and by heart rate increases > 10 bpm in 30. Five had heart rate decreases suggesting a baroreceptor response. Five had heart rate increases < 10 bpm that were possible responses to noxious stimuli. Of 30 patients with known intravascular injection and for whom ECG strips were available, 25 (83%) had T-wave amplitude increases > 25%, and 29 (97%) had ECG changes in T-wave or rhythm in response to the epinephrine injection. There were no false positives. CONCLUSION: In order to reduce risks associated with epidural anaesthesia in children, epinephrine should be added to the local anaesthetic test dose, the ECG should be monitored continuously for changes in heart rate, rhythm, and T-wave amplitude. Epidural injections should be given in small increments.     

Preparation and stability testing of a hydrogel for topical analgesia

With the commercial availability of a cream (EMLA) containing a eutectic mixture of local anaesthetics, 2.5% (w/w) lidocaine and 2.5% (w/w) prilocaine, effective topical anaesthesia of the intact skin is possible without the need for subcutaneous injections or exposure to high concentrations of local anaesthetics. In our hospital a topical anaesthetic product was designed for the same purpose. The home-made product contains a eutectic mixture of a local anaesthetic (5% w/w) and l-menthol (1% w/w). Prilocaine was used as the local anaesthetic because it is known for its safety and its well investigated analgesic effects. The eutectic mixture of prilocaine and l-menthol was mixed with a carbopol hydrogel (1% w/w). Preliminary testing of this anaesthetic hydrogel in our hospital has yielded satisfactory results. The anaesthetic hydrogel was found to be stable after at least 3 months' storage at ambient temperature.     

Intravitreal injection of cidofovir in cytomegalovirus retinitis

BACKGROUND: CMV retinitis is the most common opportunistic ocular infection and the main cause of blindness in AIDS patients with a T-helper cell count < or = 50/microliter. Cidofovir is a nucleotide analogue with a long half-life time after phosphorylation intracellularly. It is effective against CMV and can be given intravenously and intravitreally. The aim was to offer an alternative therapy for CMV retinitis to patients who could not receive standard treatment because of contraindications or refused it. The efficacy and tolerance of intravitreal injections of cidofovir should be evaluated. PATIENTS AND METHODS: We treated 16 eyes of 12 patients. The total number of injections with 15 micrograms of cidofovir each was 49, with an average of 3 injections per eye. The duration of follow-up was 75-295 days (median 170 days). Probenecid was given concomitantly. Injections were repeated after 6-10 weeks. Secondary prophylaxis of CMV organ infection was done with oral ganciclovir. RESULTS: Within a few days all areas with active retinitis turned into scars following the first injection. Under consequent treatment no reactivation was observed. Four eyes developed a mild iritis with hypotony within a mean time of 12 days after injection. All responded rapidly to topical steroids. None had a persisting loss of vision. Two eyes developed cystoid macular edema (CME). Two patients stopped anti-CMV treatment (ganciclovir orally and injections), followed by a recurrence after an average of 64-days. CONCLUSIONS: Intravitreal injection therapy with 15 micrograms cidofovir and concomitant oral probenecid is a valuable and safe alternative treatment for CMV retinitis in AIDS patients. Its main complication is iritis with hypotony, which is effectively treatable with topical steroids. No complications caused by the injection technique itself were noted. The occasional observation of CME in otherwise quiet eyes, however, is probably drug-related.     

Propofol and etomidate-Lipuro for induction of general anesthesia. Hemodynamics, vascular compatibility, subjective findings and postoperative nausea

Etomidate has become an important induction agent in high-risk patients because of its cardiovascular stability. Its unwanted side-effects such as pain on injection and thrombophlebitis could be significantly reduced by a new (medium chain triglyceride and soya bean) emulsion formulation. Propofol is solved in a mixture of long chain triglyceride and soya bean emulsion. In this double-blind, randomized study we compared the haemodynamic effects, the patients' sensations, signs of thrombophlebitis and postoperative nausea and vomiting (PONV) following injection of both drugs. METHODS: Following premedication with 2 mg Lormetazepam p.o. in 50 patients per group, anaesthesia was induced with either 0.51 mg etomidate in lipid emulsion or 3.04 mg propofol per kg bw. No opioid or benzdiazepine was given i.v. before induction. After injection of the tested drug, the cannula was removed. Changes in blood pressure and heart rate were recorded as well as signs of discomfort during and after injection (pain, burning, tension, cold). Venous sequelae were assessed for 5 days after injection to register signs of thrombophlebitis. RESULTS: Demographic data showed no difference between the two groups. After propofol more often a fall in blood pressure was seen. Pain (25 vs 1 pt), burning 19 vs 1), tension 15 vs 3), cold (35 vs 17) after injection was registered significantly more often in the propofol group, whereas myocloni predominated in the etomidate group (13 vs 6) P < 0.05, chi-squared-test). No difference was seen in PONV in either groups. CONCLUSION: Etomidate formulated in a medium chain lipid emulsion causes significant less discomfort for the patients than propofol, which is solved in a long chain formulation. Myocloni, however, occur significantly more frequently after etomidate than after propofol.     

The effect of pre-operative administration of bupivacaine compared with its postoperative use

Eighty patients undergoing lower third molar surgery under general anaesthesia were assigned to one of two groups to receive local anaesthetic blockade either 10 min prior to surgery or after surgery just before leaving the operating theatre. Patients in both groups received the local anaesthetic block whilst unconscious. Pain was assessed using visual analogue scales at 6 h and 1, 3 and 6 days after surgery. A McGill Pain Questionnaire was also completed on the morning following surgery. At no time was it possible to detect any significant difference in pain between the two groups. The administration of local anaesthesia prior to starting surgery does not appear to have any advantage over its postoperative administration in patients undergoing this type of surgery. The local anaesthetic, however, does provide excellent analgesia during the first few hours following surgery.     

Arterial anatomy of the oral cavity: an analysis of vascular territories

Knowledge of the specific cutaneous or surface regions supplied by constant named arterial sources has allowed for increasing clinical application of flap transfers of tissue. Despite the routine use of intraoral flaps for reconstruction of congenital or acquired defects of the oral cavity and pharynx, no previous investigation has centered on understanding the surface or mucosal arterial territories of the oral cavity. In a cadaver study, six mucosal territories of the intraoral cavity were defined using selective ink and lead oxide injections through named arteries. The anatomical boundaries of these territories are predictable and constant in location for different cadavers. The six contiguous territories are based on the buccal, labial, inferior alveolar, ascending palatine, ascending pharyngeal, and lingual arteries. This study supports the safe vascular basis of existing clinical procedures of the intraoral cavity and may have implications for the design of new intraoral reconstructive procedures.     

Pharmacodynamics of a liposomal preparation for local anaesthesia

A phospholipid containing formulation with tetracaine (CAS 94-24-6) for topical anaesthesia was developed. In vitro drug liberation as well as in vivo efficacy and duration of the anaesthetic effect were investigated. The in vitro liberation constant was 0-.626 +/- 0.005 mg/(cm2.square root of h for a liposomal gel formulation containing 2% (m/l) tetracaine. The gel showed high efficacy in anaesthetizing the skin after topical application. After 60 min of application complete anaesthesia of the skin was observed with all volunteers. The duration of anaesthesia after removing the application system was 150 min on average. The determination of the in vivo penetration rate resulted in values between 0.010 and 0.015 mumol/min.cm2 tetracaine.     

Rate of neuronal fallout in a transsynaptic cerebellar model

PURPOSE: A retrospective study was undertaken of the late adverse reactions following the injection of contrast media. The purpose was to determine whether there was a difference between non-ionic monomeric (iohexol) and non-ionic dimeric (iodixanol) contrast media in the reactions produced. MATERIAL AND METHODS: A total of 3,408 patients were sent a written questionnaire in which they were asked to confirm or deny any subjective discomfort or adverse event during a period of one hour to one week after a previous radiological examination with contrast medium. Patients who had undergone angiography (i.v. or i.a. injection) and CT (i.v. injection) were included. Objective signs of an allergy-like reaction were listed and the patients were asked to subjectively quantify any consequent discomfort. RESULTS: The compliance rate was 84%. Of the 3075 injections finally included in the study, 133 (4.3%) had resulted in contrast-medium-related adverse reactions of which 72 (2.3%) were immediate and 61 (2%) were late. Iohexol induced late reactions in 14/851 (1.7%) cases, and iodixanol in 24/1218 (2.0%) cases following i.v. injection and in 23/1006 (2.3%) cases following i.a. injection. The differences were not significant. There were no differences between the two contrast media in the subjective rating of discomfort except that the patients who had received iodixanol also had the highest individual-intensity score. No patient had been hospitalized owing to an adverse reaction and all reactions had been regarded as mild or moderate. CONCLUSION: The number of late adverse reactions was low. There was no difference in the frequency of the late adverse reactions following i.v. injection between iodixanol and iohexol. There was also no difference in the reactions between the i.a. and i.v. injections of iodixanol.     

Topical tetracaine attenuates the pain of infiltration of buffered lidocaine

OBJECTIVE: To determine whether topical tetracaine attenuates the pain of buffered lidocaine infiltration. METHODS: A prospective, randomized, double-blind trial was conducted involving adults with lacerations being repaired following local anesthesia. Two 0.5-mL injections of buffered lidocaine were given in a standardized manner. Injection 1 was given prior to application of topical study solution. Injection 2 was given on the opposite side of the laceration after topical application of a study solution that was 4 mL of either tetracaine or normal saline. Pain of each infiltration was measured using a visual analog pain scale. Pain score differences (injection 1 - injection 2) were compared for the 2 study solutions using a Wilcoxon 2-sample signed-rank test. RESULTS: Of 57 subjects studied, 29 received tetracaine and 28 received saline. The groups were similar in age, gender, wound length, wound location, and initial pain score. Pain scores decreased significantly in the tetracaine group as compared with the saline group. The median pain score difference for tetracaine was 12.0 mm, with an interquartile range (IQR) of 2 to 43 mm, as compared with 2 mm, with an IQR of - 17 to 21 mm for saline (p = 0.048). CONCLUSION: Topical tetracaine attenuates the pain of infiltration of buffered lidocaine.     

The influence of intrathecal fentanyl on the characteristics of subarachnoid block for caesarean section

Forty healthy parturients scheduled for elective Caesarean section were randomly allocated to receive either 0.3 ml 0.9% saline (control group, n = 20), or 15 micrograms (0.3 ml) fentanyl (treatment group, n = 20) added to 2.5 ml 0.5% hyperbaric bupivacaine given intrathecally in the sitting position. A sensory block to T4 was achieved after 6.5 min in those who received fentanyl compared to 8.0 min in the control group; this was not significantly different. The highest level of sensory block achieved in both groups was similar. Ephedrine was required earlier (p < 0.05) in those who received fentanyl but the total requirement of ephedrine intra-operatively was similar. Fentanyl significantly improved the quality of intra-operative surgical anaesthesia as none of the patients in the treatment group complained of discomfort compared with seven in the control group (p < 0.05). Similarly those in the treatment group had better comfort scores as evaluated by visual analogue score (p < 0.01). Regression of anaesthesia to T12 took longer (184 vs 156 min, p < 0.05) in those who received fentanyl but this did not affect the total requirement of morphine in the first 24 h after operation. There was no difference in the incidence of side effects in the mother and no adverse effects were detected in the baby. The results indicate that adding 15 micrograms fentanyl to hyperbaric bupivacaine for spinal anaesthesia markedly improves intra-operative anaesthesia for Caesarean section.     

Total spinal anesthesia after posterior lumbar plexus block

We report a case of total spinal anaesthesia which occurred after a lumbar plexus block using a posterior approach. After total hip arthroplasty under general anaesthesia, a lumbar plexus block was performed according to Winnie's landmarks at the L4 interspace using a nerve stimulator. Aspiration test for blood and spinal fluid were both negative, as well as a test dose of 3 mL lidocaine 2%-bupivacaine 0.5%. One minute after the injection of 27 mL of the same mixture, a complete anaesthetic block occurred with hypotension and loss of consciousness requiring intubation and controlled ventilation during 3h30, without sequelae. Lumbar plexus block using a posterior approach must be performed cautiously and a slow and fractionated injection of the full dose is recommended.