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.     

Complications during and after surgery and childbirth where spinal or epidural analgesia is used. Guidelines for safe practice

When complications and neurological sequelae occur during a spinal or epidural anaesthetic the causes are clearly related to the procedures in the following cases: severe haemodynamic or respiratory derangement, documented needle trauma of nerve fibres, intraspinal haematoma in anticoagulated or heparinized patients, and epidural infection where an infected epidural catheter entry site is documented. A number of well documented cases have been published in which surgery or patient-related pathology were primary causes of "typical" spinal or epidural neurological complications. These emphasize the importance of searching for other risk factors of neurological sequelae after surgery or child birth in cases where there is no obvious deviation from the normal epidural or spinal procedures. Increased focus on the infrequent, but serious complications of these essentially very safe techniques for surgical anaesthesia and pain relief should serve to increase our vigilance, but should not reduce the application of spinal and epidural analgesia. Guidelines are offered for the effective and safe practice of spinal and epidural anaesthesia and pain relief: adequate supervision of trainee anaesthetists, vigilant monitoring for early detection and handling of complications, and trained nurses on surgical wards to monitor and handle patients during epidural analgesia are important. Sufficient readiness for urgent handling of the very rare, but devastating complications of intraspinal bleeding or infection is an absolute necessity.     

Localization of PTH gene on pig chromosome 14q25-q28 by in situ hybridization

BACKGROUND AND OBJECTIVES: A survey of anesthesia practice was conducted among French residents in anesthesia at the end of their training. This study was performed mainly to evaluate the residents' experience in peripheral nerve blocks. METHODS: Two short clinical cases were proposed to all French residents during a telephone interview immediately before their certification. The first described the case of a young asthmatic patient admitted for an elbow fracture. The second described an elderly woman with severe aortic stenosis admitted for a supracondylar fracture of the femur. A questionnaire had been prepared and was filled in during the interview. Each resident was asked to answer according to the actual choice he or she would have made. For both cases, when general anesthesia was chosen first, the next question was to discuss which regional anesthesia would be used if general anesthesia had to be discarded. In that way, the practical knowledge about most common peripheral nerve blocks learned during residency was investigated. RESULTS: Of 77 residents registered as being at the end of their residency, 8 were on either sabbatical or maternity leave. Regional anesthesia was the first choice in 78% and 57% of cases for the first and second clinical cases, respectively. The regional anesthetic techniques chosen were axillary block (66%), interscalene block (31%), and intravenous regional anesthesia (3%) for case 1 and combined lumbar plexus and sciatic block (36%), epidural anesthesia (30%), single-shot spinal anesthesia (18%), and continuous spinal anesthesia (16%) for case 2. Throughout the residency of the group, 32 +/- 2 axillary blocks, 12 +/- 2 interscalene blocks (axillary vs interscalene, P < .0001), 21 +/- 3 femoral blocks, and 10 +/- 2 sciatic blocks (femoral vs sciatic, P < .0001) had been performed (mean +/- SEM). They had also performed 2.5 +/- 0.5 continuous spinal anesthesias and 17 +/- 3 intravenous regional anesthesias respectively. Upper extremity blocks were more often used during residency than lower extremity blocks (44 +/- 3 vs 31 +/- 4, P < .01). A peripheral nerve stimulator was routinely used by 83% of residents. CONCLUSION: French residents in anesthesiology at time of certification are better trained for peripheral nerve blocks of the upper extremity than for those of the lower extremity. Axillary plexus and femoral nerve block are the most widely used blocks, probably reflecting the techniques the most mastered among teachers. Finally, the extensive use of a peripheral nerve stimulator by residents is probably the result of the widespread use of this device by teachers in France.     

Motor deficit of the lower limbs and urinary incontinence following peridural anesthesia

Neurological complications of epidural anaesthesia are rare, but can be severe. We report the case of a 49-year-old man, with a history of non equilibrated diabetes, who experienced after an epidural anaesthesia for peripheral vascular surgery a polyneuropathy with muscle weakness of the lower extremities associated with a transient urinary incontinence. A spinal compression was excluded by computed tomography and magnetic resonance imaging. Electromyography showed an impaired nervous motor conduction. An aggravation of a pre-existing diabetic and alcoholic polyneuropathy, associated with possible spinal ischaemia of multifactorial origin could be the cause of these complications. This case emphasizes the importance, during preanesthetic assessment of candidates for epidural or spinal anaesthesia, to search for a possible unrecognized neuropathy at risk of aggravation by regional anaesthesia.     

Percutaneous epidural and nerve root block and percutaneous lumbar sympatholysis

Epidural steroid injections and selective nerve root blocks currently are considered standard techniques in the diagnosis and treatment of back pain. The targeted epidural and perineural steroid injection with nerve block is a new technique that combines an epidural steroid injection and a nerve block. Radiologists are best suited for performing these procedures because of their training and skills in fluoroscopy and needle procedures.     

Obstetric analgesia in Norwegian hospitals]

We report the results of a questionnaire sent to anaesthetists and midwives on the use of obstetric analgesia and anaesthesia in Norwegian hospitals in 1996. 95% of the 49 hospitals involved responded to the questionnaire, representing a total of 56,884 births. The use of epidural analgesia in labour varied from 0 to 25% in the different hospitals with a mean value of 15%. Epidural analgesia was much more widely used in university and regional hospitals than in local hospitals (p < 0.001). Five of the local hospitals did not offer epidural analgesia during labour at all. The combination of low-dose local anaesthetic and an opioid (either sufentanil or fentanyl) had not been introduced in nine of the hospitals (20%). The optimal use of epidural analgesia to relieve labour pain was judged to be more frequent by the anaesthetists than by the midwives (19% versus 11%, p < 0.01). In response to what factors limited the frequency of epidural analgesia, the anaesthetists specified factors related to the attitude of the midwife, and the midwives specified factors related to the anaesthetist. Only five of the hospitals provided written information on the various analgesic methods that could be employed during labour. The majority of midwives considered the analgesic methods employed on their maternity ward to be good or excellent. The frequency of Caesarean section was 12%; spinal anaesthesia was used in 55%, epidural anaesthesia in 17%, and general anaesthesia in 28% of the cases.     

Combined spinal and epidural anesthesia. A review of the method

Combined spinal epidural anaesthesia (CSE) offers the fast and profound neural blockade of spinal anaesthesia, but provides the possibilities of extension of the block and post-operative pain control. On the basis of a historical review, the advantages and drawbacks of CSE are discussed, and purpose-designed needles (Eldor 1 and 2, E-SP, T-A, Braun, Mediziv) are described. The dosage problems inherent in the technique and a possible solution to the "test dose" question are described. In conclusion: CSE is a valuable alternative to established regional anaesthetic techniques. The Mediziv needle offers several advantages, but a comparative study of the different needle types is needed.     

Concomitant rash and blood dyscrasias in geriatric psychiatry patients treated with carbamazepine

PURPOSE: To present two successful cases of labour analgesia in patients who had been treated with radiation to the lumbar spine for neuroblastomas and to discuss the considerations when planning the anaesthetic management of these patients. CLINICAL FEATURES: We recently encountered two primigravidas requesting labour analgesia, both of whom were noted to have very thin backs with prominent spinous processes and obvious scoliosis. In both patients, the epidural space was easily identified and very shallow. Successful labour analgesia was achieved in both patients, one with a combined spinal epidural technique and the other with an epidural catheter. CONCLUSION: Craniospinal irradiation is known to have long-term effects on exposed nervous tissue, bone, and blood vessels. While a larger experience is necessary to demonstrate safety of regional anaesthesia in parturients following previous spinal irradiation, we provide reports of two successful cases.     

Sciatic nerve palsy following childbirth

Two cases are reported of sciatic nerve palsy after delivery by Caesarean section in primigravidae. One mother was slender and had an emergency Caesarean section for failure to progress with a breech presentation. Epidural analgesia during labour was extended for operative delivery. The other mother was obese, mildly hypertensive, had a large baby with a high head and was delivered by elective Caesarean section under epidural anaesthesia. She experienced severe intrapartum hypotension. Both patients suffered right sided sciatic nerve palsy. The aetiologies of obstetric palsies and those following regional block are reviewed and the importance of careful diagnosis and of avoiding peripheral nerve compression during regional block are emphasised.     

Anaesthetic considerations for children undergoing stereotactic radiosurgery

An anaesthetic case report of children undergoing stereotactic radiosurgery is presented, with a review of the inherent unique anaesthetic challenges. Twelve stereotactic radiosurgery procedures performed at The Prince of Wales Hospital, Sydney, were retrospectively reviewed. Despite differences in approach by individual anaesthetists to managing these children, an overall safe sequence may be evolved. The use of stereotactic radiosurgery for paediatric neuropathology is reviewed. The potential anaesthetic problems related to the paediatric patient and the peculiarities of the procedure are discussed and related to our series.     

Exposure of the pediatric surgeon to inhalation-anesthetic during pediatric bronchoscopy procedures

BACKGROUND: General anaesthetic agents are frequently used for paediatric bronchoscopy. A disadvantage of this open system anaesthesia seems to be the contamination of the working environment. The aim of this study was to determine the exposure of the endoscopist during paediatric bronchoscopy under general anaesthesia in different working environments and to compare these measurements with the currently valid international threshold limit values. MATERIAL AND METHODS: 25 children (ASA I-III) scheduled for diagnostic bronchoscopy were included in the study. After inhalational induction all children were intubated with a nonflexible bronchoscope and manually ventilated through a side arm of the bronchoscope. Maintenance of anaesthesia was achieved with sevoflurane (2-3 vol%) in 80% oxygen. Trace concentrations were measured every 90 seconds in the breathing zones of the paediatrician by means of a highly sensitive direct-reading instrument (Brüel & Kjaer 1302). The lower detection limit was 0.02 ppm. The investigation was done in an OT with and without air conditioning and scavening system. RESULTS: The mean age of the children was 50.3 months (range: 3-109 months). Ventilation and oxygenation were stable throughout the bronchoscopic procedure. Mean exposure of the paediatrician without air-conditioning and scavening system to sevoflurane was over 50 ppm for the endoscopist. All international threshold limit values were exceeded. Peak concentrations higher than 100 ppm sevoflurane were detected repeatedly in 40% of anaesthesias. During bronchoscopy in the operating room equipped with laminar air flow (20.2 air exchanges per hour) and narcotic gas evacuation (30 l/min) the mean exposure of the paediatrician was 26.4 ppm sevoflurane. CONCLUSIONS: The main finding of the present study is that under inhalation anaesthesia with sevoflurane for paediatric bronchoscopy occupation exposure is higher than the limits stated in all known health regulation guidelines. Therefore, in case of such working conditions, the use of total intravenous anaesthesia is advocated also in very small infants.     

Unexpected cardiac arrest during epidural anaesthesia

We reported the case of sudden asystole requiring close chest cardiac massage in a 56-yrs-old health man receiving epidural anaesthesia for elective transurethral resection of bladder tumour (TURBT). The anaesthetic procedure was performed in a regional-block-room. Cardiac arrest developed few minutes after local anaesthetic injection, before the patient has been transferred to the operating room. The importance of patient monitoring during regional anaesthesia must be further on pointed out, especially when the anaesthetic procedure is performed out of the operating room (e.g. in the recovery room or in a "regional-block-room").     

Lower limb blocks in children

Conduction blocks have important advantage over spinal blocks for unilateral low extremity surgery in children. The complexity of innervation compared with upper limb is more apparent than real and a good understanding of fascial diffusion spaces is as essential as it is of neural pathways. Useful techniques can be classified into two groups, proximal blocks and distal blocks. Beside emergency situations, proximal blocks are usually performed under light general anaesthesia, with the aid of a neurostimulation. The most used proximal blocks are the femoral block, the sciatic nerve block and to a lesser degree the lumbar plexus direct blockade. Distal blocks can complete a non quite satisfactory proximal block, or be effected so as to obtain analgesia in a limited area (in a cooperative vigil patient). Some of these consist of several anaesthetic subcutaneous infiltrations for which no costly material nor special dexterity are required. A judicious choice among the main available techniques allows an excellent analgesia with a very low cost and almost no risks.     

Arthur L?wen--a pioneer of modern anesthetic techniques

The development of modern local anaesthetic techniques is connected with the name of Arthur L?wen. At the turn of this century, he started his surgical training with Heinrich Braun, who had performed a lot of research with various local anaesthetic methods and who was renowned world-wide as an authority for his contributions. It is not surprising that a main topic of L?wen's research was the development of new local anaesthetic regimes. In close collaboration with the Institute of Pharmacology at the University of Leipzig, he examined new available local anaesthetic drugs and their practicability for daily use. Due to an own, new pharmacological preparation of a bicarbonated novocaine solution, paravertebral, sacral and epidural conduction blocks became a reality in clinical practice. Thus several, still valid methods in the treatment of acute or chronic pain became manageable. The further development of new techniques for the differential diagnosis of various illnesses must also be mentioned. A remarkable step towards a modern anaesthesia concept was the administration of curare for muscle relaxation in operative surgery. Another evidence of his foresight are his contributions in the development of an electrically driven apparatus to overcome respiratory failure "L?wen was in many ways a man before his time:" This appraisal by a surgeon colleague is true even today for several of his anaesthesia-related contributions, which are still part of the armamentarium of modern anaesthetic methods.     

Hepatitis C virus infection and heart diseases: a multicenter study in Japan

We present our experience of transcutaneous truncal anaesthesia of the maxillary nerve in association with transmucosal anaesthesia of the sphenopalatine ganglion in surgically assisted rapid maxillary expansion. Twelve patients with a skeletal transverse discrepancy of the maxilla were treated in our department from 1994 to 1995. Maxillary transcutaneous nerve block was done with a Quincke 8 cm spinal needle together with transmucosal anaesthesia of the sphenopalatine ganglion. Mepivacaine without adrenaline and sodium bicarbonate 1/10 was used for truncal anaesthesia and lidocaine-prilocaine cream for transmucosal anaesthesia. A Le Fort I osteotomy, lateral nasal wall osteotomy, pterygomaxillary osteotomy, and a palatal osteotomy were done for all patients before the maxillary expansion. Total anaesthesia of the maxillary area facilitated the operations and appreciably reduced the amount of postoperative pain. The ease of achieving effective anaesthesia before and after operation and the absence of side-effects make this form of anaesthetic particularly useful in surgically assisted rapid maxillary expansion.     

Anaesthesia of the tympanic membrane using iontophoresis

Experience is described of the use of iontophoresis of 2% lignocaine to achieve effective tympanic membrane anaesthesia. The main uses are for outpatient myringotomy and transtympanic electrocochleography. Complete anaesthesia of the drum has been obtained in all cases, and those patients who had previously had these procedures carried out without anaesthetic, or with surface 'anaesthesia' only, all stated a marked preference for iontophoresis. No complications have occurred.     

The low-molecular-weight phosphotyrosine protein phosphatase, when overexpressed, reduces the mitogenic response to macrophage colony-stimulating factor and tyrosine phosphorylation of its receptor

Inert gases at raised pressure exert anaesthetic effects. It is assumed that anaesthesia by the inert gases is fundamentally similar to anaesthesia produced by general anaesthetics. However, do general anaesthetics bind directly to proteins or influence activity by indirectly perturbing membrane lipids still remains a major question. Although the pressure required to achieve anaesthesia with inert gases has been suggested to exert potentially some pressure antagonism per se, this has not been studied yet to our knowledge. We investigated this possibility using nitrogen, argon, and nitrous oxide. Whatever the narcotic agent used, our results showed that the pressure of narcotic required to induce anaesthetic effects increased, as compression rate increased, in a sigmoid fashion rather than in a linear fashion. Evidence for sigmo?dal responses vs. linear responses depended of the narcotic potency of the anaesthetic agent used (nitrogen: r2=0.973 vs. r2=0.941; argon: r2=0. 971 vs. r2=0.866; nitrous oxide: r2=0.995 vs. r2=0.879). Since a linear antagonism is predicted by lipid theories, we think it likely that these findings indicate that inert gases bind to a modulatory site of a protein receptor and act as allosteric modulators. Since other workers provided evidence for binding processes using volatile anaesthetics, the present findings could indicate that all classes of general anaesthetics, including inert gases, could act by binding directly to proteins rather than by dissolving in some lipids of the cellular membrane.     

Effectiveness of obstetric epidural analgesia. II. Caesarean section

A questionnaire was sent to 260 women who in 1979 had undergone a caesarean section under either epidural or general anaesthesia. Those women who had an epidural for their caesarean section were on average very well informed about the procedure. In contrast, those who had been given a general anaesthetic felt that they had been badly or inadequately informed. Over 90% of the patients of both the epidural and the general anaesthetic groups described the type of anaesthesia which they had received as "very good" to "adequate". In the epidural group, 80% of the patients described the experience of the birth as very intense. Headache, back pain and other complaints such as abdominal pain and wound pain were significantly more frequent in the general anaesthetic as compared to the epidural group. 85.8% of the women given an epidural said that they would choose the same again for a future caesarean, 12.1% would not. Of the group given a general anaesthetic, 29.9% said that in the future they would choose an epidural, and 62.3% that they would prefer to have a general anaesthetic again. The Apgar score at one minute, and the umbilical artery pH values of the newborn of the epidural group were significantly better than those of the general anaesthetic group, whereas at 5 and 10 min the Apgar scores of the babies of both groups showed no differences.     

Ropivacaine 7.5 mg/ml for elective caesarean section. A clinical and pharmacokinetic comparison of 150 mg and 187.5 mg

BACKGROUND: The new, long-acting local anaesthetic ropivacaine has shown less systemic toxicity than bupivacaine and a concentration of 7.5 mg/ml can therefore be used for epidural anaesthesia in Caesarean section. The present pilot study was undertaken to find indications for an optimal dosage by comparing the clinical effects, quality of anaesthesia and pharmacokinetics of ropivacaine 150 mg (lower dose = LD) vs 187.5 mg (higher dose = HD) for women undergoing elective Caesarean section under epidural anaesthesia. METHODS: Sixteen full-term women scheduled for elective Caesarean section in two equal-sized consecutive groups received 20 or 25 ml ropivacaine epidurally in this non-randomised, open study. Study parameters included sensory and motor blockade, circulatory response, intraoperative pain and discomfort, neonatal evaluation and pharmacokinetic determinations. RESULTS: Block height varied between T5 and T2 in the LD group, whereas the HD group produced 4 unnecessarily high blocks (C8 in 3 women and C7 in 1 woman). Surgical anaesthesia was excellent in both groups. Circulatory stability was pronounced in the LD group (no ephedrine given), while 4 women required ephedrine in the HD group. Neonatal outcome as judged by Apgar scores; umbilical blood gas determinations and NACS scores were excellent in both groups. The plasma concentration-time profiles indicated linearity in the concentration range studied, with similar clearance values to those reported previously. Placental drug equilibrium was rapid; however, the foetal drug exposure depended on intrauterine exposure time. CONCLUSIONS: 20-25 ml ropivacaine 7.5 mg/ml produced very satisfactory conditions for elective Caesarean section under epidural anaesthesia. In this small population, 150 mg ropivacaine seemed optimal, while 187.5 mg produced unnecessarily extended block height in 50% of the women.