A new experimental device for the measurement of moisture emission and heat release from respiratory organs and body surface

BACKGROUND: The majority of patients with peripheral vascular disease have associated medical illnesses that contribute to a substantial incidence of perioperative complications. Some of the these complications may be related to the choice of anesthetic used. An ideal anesthetic would provide good analgesia, have few complications associated with its use, including minimizing hemodynamic instability, and provide an adequate surgical environment. MATERIALS AND METHODS: Ten patients with an occluded superficial femoral artery and claudication or rest pain were selected. Eligibility criteria were a non-obese thigh and an above knee popliteal segment of at least 10 cm. Lidocaine local anesthesia with systemic sedation was employed. Above knee femoropopliteal bypasses were performed in all patients. Intraoperative fluid volume, anesthetic dose and perioperative morbidity were recorded. RESULTS: All patients tolerated the procedure well. The operating environment was excellent. Intraoperative fluid requirements were less for patients receiving local anesthesia as compared with a similar group of patients undergoing above knee femoropopliteal bypass receiving regional anesthesia (mean 1750 ml versus 3386 ml). The mean dosage of lidocaine (0.5%) was 367 mg over a mean of 116 min operating time. All patients ambulated within 8 hours. There was no perioperative morbidity, mortality or graft occlusion. CONCLUSION: This technique is easy to perform and further reduces the systemic magnitude of anesthesia, while providing excellent perioperative analgesia and a satisfactory surgical environment. It may be ideal for the high risk patient, as intraoperative fluid volume requirements are reduced. In an era where endoluminal bypass grafting is being increasingly advocated, this technique retains the benefits of bypass grafting while possibly reducing the physiological insult.     

Use of preoperative subcutaneous "wetting solution" and epidural block anesthesia for liposuction in the office-based surgical suite

Uniform saturation of subcutaneous fat using the "wetting solution" formula described by Klein for his "tumescent technique" has been shown to decrease operative blood loss associated with liposuction procedures and to eliminate the requirement for general anesthesia for selected patients. However, we found this infusate provided an inadequate level of anesthesia for many of our patients. We use preoperative infusion of Klein's epinephrine and lidocaine containing wetting solution in our lipoplasty practice only for control of blood loss and postoperative pain. Our anesthetic of choice for liposuction is the epidural block technique, which provides consistent intraoperative comfort for the patient. We report our experience with 85 consecutive lipoplasty patients who underwent liposuction under epidural anesthesia after subcutaneous fat perfusion with Klein's wetting solution. Our epidural block technique uses the rapidly metabolized local anesthetic agent, chloroprocaine, which has the lowest systemic toxicity risk of any local anesthetic agent. Chloroprocaine's anesthetic characteristics are particularly well suited for the outpatient surgery patient with few undesirable side effects.     

Transarterial brachial plexus anesthesia for hand surgery: a retrospective analysis of 346 cases

STUDY OBJECTIVES: To study the safety and efficacy of the transarterial approach to brachial plexus block with 60 to 70 ml of local anesthetic solution, and to compare the success and complication rates of this block performed by experienced or inexperienced anesthesiologists. DESIGN: Retrospective analysis of 346 records of ASA physical status I-IV patients who underwent elective unilateral orthopedic upper limb surgery with transarterial plexus anesthesia. SETTING: University teaching hospital. MEASUREMENTS AND MAIN RESULTS: Blood pressure (BP) and heart rate were measured at 5-minute intervals. Analgesia was registered as successful, incomplete, or failed. Any patient complaints or adverse reactions were recorded. The first 60 ml of local anesthetic provided surgical analgesia to 64% of patients. With a supplemental 10 ml of anesthetic, the overall success rate was 94%, with only 19 of 346 patients requiring general anesthesia. Experience in performing the block increased the success rate from 90% to 98% (p < 0.001). Six patients experienced either nausea or a transient BP decrease that did not require medication. There was no record of toxic or other serious adverse reaction. CONCLUSIONS: Transarterial brachial plexus block administered with a 60 to 70 ml dose of local anesthetic provides surgical analgesia for hand surgery with an excellent success rate and without serious adverse effects.     

Regional nerve block for total knee arthroplasty

Femoral and sciatic nerve blocks have been used occasionally for unilateral total knee arthroplasty (TKA). In order to evaluate the effectiveness of this technique, combined femoral 3-in-1 and sciatic nerve blocks were performed in 20 cases of TKA, by the same surgeon. This surgeon also performed unilateral TKA under spinal anesthesia in another 20 cases. The anesthetic effectiveness of the two types of anesthesia was compared in terms of the time needed to complete the surgery, amount of intraoperative blood loss, and time interval until the first dose of analgesic. The results showed that the two types of anesthesia had comparable anesthetic effects. Ten of the 20 patients who had spinal anesthesia complained of postoperative urinary retention, while none of those who had nerve block had this complaint. Neither group experienced postpunctural headache, neurovascular damage, or drug-over-dose toxicity. We conclude that combined femoral 3-in-1 and sciatic nerve block is an effective anesthetic alternative for unilateral TKA.     

Subunit peptide cancer vaccines targeting activating mutations of the p21 ras proto-oncogene

BACKGROUND AND OBJECTIVES: Physicians in the 1920s and 1930s began to treat patients with chronic pain syndromes using regional anesthetic techniques for both temporary and permanent block of pain pathways. The founding of the American Society of Regional Anesthesia (ASRA) in 1923 provided a unique venue for the dissemination of information concerning regional anesthesia for both surgery and chronic pain management. METHODS: The growth of chronic pain management on a national basis was assessed by using the Quarterly Cumulative Index to the Medical Literature to trace the distribution of information on regional anesthesia. From the Minutes of Meeting of the American Society of Regional Anesthesia, presented papers and the discussion that followed were analyzed. RESULTS: Inquiries into regional anesthesia during the 1920s and 1930s predominantly dealt with technique. For the first time pain papers were listed under the regional anesthesia heading in the Index. The papers presented at ASRA meetings during the period helped develop the use of regional anesthesia for both chronic pain management and surgical anesthesia. CONCLUSIONS: The ASRA was instrumental in bringing together physicians interested in regional anesthesia and pain management. During the 1930s physician anesthetists came to predominate as the organization's officers and members and helped translate the work of the ASRA into a part of the knowledge required to be a specialist physician in anesthesia.     

Comparison of the clinical efficacy of three perivascular techniques for axillary brachial plexus block

BACKGROUND AND OBJECTIVES: This study compared the efficacy of three perivascular techniques of axillary block. METHODS: In group 1, all of the local anesthetic was injected after advancing the needle through the axillary artery (back of artery, n = 20); in group 2, after withdrawing slightly from the artery (front of artery, n = 20); and in group 3, half of the anesthetic was injected after advancing through and half after withdrawing from the axillary artery (half and half, n = 20). The local anesthetic used for the axillary block was 50 ml of 1.5% mepivacaine with epinephrine 1:200,000. RESULTS: The groups did not differ significantly in the incidence of analgesia or anesthesia expected in the median nerve distribution, where there was a significantly lower incidence of anesthesia in the back of the artery group. This group also had a slower onset of anesthesia for the median and the medial antebrachial cutaneous nerves. CONCLUSIONS: There was no significant difference in the number of patients requiring supplementation, with five patients in the back group (25%), three patients in the front group (15%), and one patient in the half and half group (5%) requiring supplementation for the surgical procedure.     

Combined spinal and epidural anesthesia for cesarean section in a parturient with moyamoya disease

We present the case of a parturient with moyamoya disease admitted to the hospital for elective cesarean section. Combined spinal and epidural technique was chosen because it allows better analgesia than epidural anesthesia and more hemodynamic stability than either general or spinal anesthesia. Ropivacaine was the local anesthetic of choice for the epidural portion because of the wide sensory-motor dissociation, thus preserving adequate respiration in the case of a high block.     

Pain in the lower extremities after subarachnoid block with lidocaine

Subarachnoid block is a widely practiced anesthetic technique. With the availability of small-diameter needles and the rises in out-patient surgery, the number of procedures performed with subarachnoid block and short-term local anesthesia have increased. We report two cases of bilateral pain in the lower extremities appearing 20-24 h after intradural anesthesia with 2% hyperbaric lidocaine. We analyze the factors that might have triggered this complication and compare the two patients with 14 others described in the literature. Three points in common were found: the use of hyperbaric lidocaine, administration of the agent through small gauge needles and the performance of out-patient surgery.     

A 21st century computerized injection system for local pain control

This article describes a new computerized local anesthetic injection system for pain control. The core technology of this system is the microprocessor-controlled delivery of anesthetic solution at a constant pressure and controlled volume, regardless of encountered variations in tissue resistance. This fine-tuned, high suffusion flow rate of anesthetic provides a rapid onset of anesthesia for most patients. Traditional block injections and infiltrations as well as palatal injections and periodontal ligament injections are administered with precision, ease, and patient comfort.     

Suprascapular nerve block for postoperative pain relief in arthroscopic shoulder surgery: a new modality?

Arthroscopic shoulder surgery has a 45% incidence of severe postoperative pain. Opiates and interscalene nerve blocks have a high incidence of side effects, and intraarticular local anesthetic has been shown to be ineffective when used for postoperative pain relief. The suprascapular nerve supplies 70% of the sensory nerve supply to the shoulder joint, and local anesthetic block of this nerve is effective in certain shoulder pain disorders. To determine the efficacy of a suprascapular nerve block, subcutaneous saline was compared with a suprascapular nerve block using 10mL of 0.5% bupivacaine with 1:200,000 epinephrine before general anesthesia was induced. In the immediate postoperative period, a 51% reduction in demand and a 31% reduction in consumption of morphine delivered by a patient-controlled analgesic system was demonstrated. There was more than fivefold reduction in the incidence of nausea, as well as reduced visual analog and verbal pain scores for patients who received a suprascapular nerve block. The duration of hospital stay was reduced by 24% in the suprascapular nerve block group. A 24-h phone call interview revealed a 40% reduction in analgesic consumption and a reduction in verbal pain scores at rest and on abduction. There were no complications from the suprascapular nerve block. This study demonstrates that a suprascapular nerve block for pain relief in arthroscopic shoulder surgery is an effective and safe modality of postoperative pain relief.     

Benchmarking the perioperative process: III. Effects of regional anesthesia clinical pathway techniques on process efficiency and recovery profiles in ambulatory orthopedic surgery

STUDY OBJECTIVES: (1) To incorporate regional anesthesia options for common outpatient orthopedic surgery into clinical pathways; (2) to use the clinical pathway format and the Procedural Times Glossary published by the Association of Anesthesia Clinical Directors (AACD) as management tools to measure postoperative same-day surgery processes and discharge outcomes; and (3) to determine the effects of general, regional, and combined general-regional anesthesia on these processes and outcomes. DESIGN: Hospital database and patient chart review of consecutive patients undergoing anterior cruciate ligament reconstruction (ACLR) during academic years (AY) 1995-1996 and 1996-1997. Patient data from AY 1995-1996, during which no intraoperative anesthesia clinical pathway existed, served as historical controls. Data from AY 1996-1997, during which intraoperative anesthesia clinical pathways were used, served as the treatment group. SETTING: Ambulatory surgery center in a teaching hospital. MEASUREMENTS AND MAIN RESULTS: The records of 503 ASA physical status I and II patients were reviewed. 1996-1997 patients selected general anesthesia (+/- femoral nerve block) or epidural anesthesia, after which the remainder of the perioperative anesthesia process was standardized with respect to the drugs and equipment used. 1995-1996 patients did not necessarily have a choice in anesthesia technique and did not have a standardized perioperative anesthetic course with respect to specific drugs and supplies. Intervals described in the AACD Procedural Times Glossary, anesthesia drug and supply costs, and patient outcome variables (postoperative nursing interventions required and unexpected admissions), as influenced by anesthesia technique used, were measured. Combined general-regional anesthesia care for ACLR in 1996-1997, when compared with general anesthesia alone, led to increased pharmacy and materials costs and increased turnover time. However, patients with the combined technique showed improved recovery profiles and lower unexpected admission rates, and they required fewer nursing interventions for common postoperative symptoms. Patients receiving epidural anesthesia showed discharge outcomes similar to those patients receiving general anesthesia with femoral nerve block. Postanesthesia care unit bypass (fast-tracking) was more likely in clinical pathway regional anesthesia patients, when compared with the clinical pathway general anesthesia used. CONCLUSIONS: Clinical pathway regional anesthesia care for outpatient orthopedics may have a significant role in simultaneously containing costs and improving both process efficiency and patient outcomes.     

Evaluation of local anesthesia techniques for small incision cataract surgery

PURPOSE: To evaluate the surgical experiences and patient preference with 3 local anesthesia techniques for small incision cataract surgery. SETTING: Department of Ophthalmology, Hj?rring Hospital, Denmark. METHODS: This prospective, randomized study included 66 patients having simultaneous bilateral cataract surgery. There were 3 test groups, each containing 2 of the following local anesthesia techniques: retro/peribulbar (RBA), sub-Tenon's (STA), or topical (TA). Each patient served as his or her own control. No medical sedation was used. Patient response to each anesthesia technique was evaluated by the surgeon based on surgical difficulties, a nurse using hand-holding tension and verbal interaction, and a visual analog pain score. Patients were also asked which of the 2 techniques they preferred and their reasons. RESULTS: No local anesthesia techniques interfered with surgery. The order of a positive pain/discomfort response during surgery was TA > STA > RBA. Significantly more pain occurred with application of RBA than with STA or TA. No postoperative pain was recorded with any method. Fifty-six percent of patients said they preferred 1 technique over the other; 16% of patients having STA would not do so again, 19% would not have TA again, and 40% would not have RBA again. The main reasons for preferring STA and TA were fear of or pain from a retrobulbar injection. The main reasons for preferring RBA were less awareness, anxiety, and surgical pain. Immediate visual recovery seemed to be of minor importance in patients' choice of an anesthesia technique. CONCLUSION: Although less discomfort/pain occurred during surgery with RBA, patients preferred STA and TA primarily because of the inconvenience or pain of the retrobulbar injection. Although medical sedation was not used in this study, the pain/discomfort ratio from surgery was not greater than in studies using intravenous sedation, indicating that the use of medical sedation should be re-evaluated.     

Fever attributed to the use of hydroxyurea

Preemptive analgesia has recently been the subject of much discussion in the literature including a recent editorial which describes some of the difficulties surrounding the subject. The concept of preemptive analgesia is frequently misunderstood by anesthesia providers especially relative to the use of regional anesthesia. This confusion hampers anesthetists in their practice when they seek to provide optimal pain care for their patients, and especially when regional block is not an option in their particular practice or is inappropriate either for the individual patient or for the surgery being undertaken. This article attempts to differentiate preemptive analgesia from regional anesthetic blockade, and discusses other interventions which may also play a role in producing some measure of preemptive effect.     

Prospects of the use of caudal epidural anesthesia

Caudal epidural anesthesia for interventions on the lower limbs and pelvic organs was used in 525 patients. A specific feature of the method is use of hypoosmolic local anesthetic solution (osmolality 260 mosmol/kg) containing lidocaine, 0.9% sodium chloride, and distilled water. Pathologic studies showed that in adult patients, at least 40 ml anesthetic should be injected into the caudal canal for adequate blocking. During surgery, caudal epidural anesthesia reliably protected from surgical trauma without side effects for respiration and circulation. The duration of analgesic effect was 3 +/- 0.5 h and even longer, if local anesthesia was potentiated with sedative drugs. No complications were observed, failures occurred in 5.2% cases. The method is simple and reliable and is recommended for practice.     

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.     

Analysis of health service areas: another piece of the psychiatric workforce puzzle

PURPOSE: To establish the benefit of nonpreserved intracameral lidocaine 1% as an adjunctive anesthetic agent to topical anesthesia for small incision cataract surgery and to determine the agent's safety with respect to corneal toxicity. SETTING: Advanced Vision Care, West Hills, California, USA. METHODS: A retrospective chart review of cataract surgery performed between January 1995 and March 1997 was done. The efficacy of intracameral lidocaine was determined by comparing the number of topical anesthesia cases (Group 1) and of combined topical and intracameral anesthesia cases (Group 2) that required conversion to a more profound level of local anesthesia, determined by patient discomfort, surgeon discomfort, or both. To determine the presence and bias of a surgical learning curve, Group 1 was subdivided chronologically into two subgroups. Corneal toxicity was assayed by the degree of clinical corneal edema noted by slitlamp examination on the first postoperative day. RESULTS: Six hundred thirty-one charts satisfied the criteria for inclusion; 352 cases (Group 1) had topical anesthesia alone and 279 subsequent cases (Group 2), combined topical and intracameral anesthesia. In Group 1, 42.6% of cases required conversion to some form of additional local anesthesia, whereas in Group 2, less than 1.0% required conversion. In the earlier subgroup, 45.8% of cases required conversion and in the latter, 34.3%. On the first day after surgery, 88.2% of Group 2 cases and 76.7% of Group 1 cases were free from corneal edema. The difference was statistically significant but probably resulted from a change in phacoemulsification technique from sculpting to chopping in the latter cases, which were performed under combined topical and intracameral anesthesia. CONCLUSIONS: Intracameral nonpreserved lidocaine 1% appears to be both efficacious and nontoxic as an anesthetic adjunct in small incision cataract surgery.     

Incremental bolus versus a continuous infusion of propofol for deep sedation/general anesthesia during dentoalveolar surgery

PURPOSE: This article compared the use of the traditional incremental bolus technique with the continuous infusion technique for the administration of propofol for deep sedation/general anesthesia. PATIENTS AND METHODS: Patients were sedated with midazolam and fentanyl and then had maintenance of an anesthetic state achieved with propofol administered by either of the two techniques. Data were collected to evaluate the overall surgical/anesthetic procedure, movement of the patient, and his or her hemodynamic status. RESULTS: Both groups received a mean maintenance dose of propofol exceeding 6 mg/kg/hr. However, the patients in the continuous infusion group received a statistically greater maintenance dose (continuous infusion + supplemental vs incremental bolus). All patients were maintained in a deep sedation/general anesthetic state. Respiratory and blood pressure values were comparable in both groups. However, the continuous infusion group showed improved hemodynamic stability manifested as fewer fluctuations in heart rate. Visual analog scale (VAS) questionnaires completed by the surgeon and surgical assistant reported less patient movement and improved surgical/anesthetic conditions with the continuous infusion technique. Recovery of the two groups was comparable. CONCLUSION: This study, although finding advantages in the continuous infusion technique, showed satisfactory conditions associated with both techniques.     

Effects of maternal anesthesia in the neonate

All commonly used anesthetic agents and drugs undergo placental transfer. Understanding the placental transfer of anesthetic drugs and their effects on the neonate is essential for optimal administration of both regional and general anesthesia. Regional anesthesia is decidedly safer for the mother and, when properly performed, actually may be beneficial to the stressed neonate. The healthy neonate also benefits from maternal analgesia during labor and delivery. General anesthesia may result in transient neonatal depression, particularly when delivery is of an emergency nature. The skill and knowledge of the anesthesiologist are more important than the type of anesthesia administered. Therefore, when properly performed, both regional and general anesthesia are quite safe in terms of neonatal outcome.     

Understanding conscious sedation in the operating room

Conscious sedation is an appropriate choice for patients who do not require a general anesthetic, but rather need sedation to alleviate anxiety, minimize the discomfort of less invasive surgical procedures, or even to tolerate a regional or local anesthetic. New pharmaceutical agents, with their short half lives, provide amnesia, analgesia, and sedation quite safely. This concept, combined with standardized and controlled safety monitoring, offers an anesthetic alternative quite acceptable to many patients and health care providers. Standards and guidelines have been extensively developed by the American Society of Anesthesiologists, and the American Association of Nurse Anesthetists, to set forth a practice for all providers that will promote patient safety and provider vigilance (AANA, 1998). The purpose of this article is to review the process of conscious sedation.     

Femoral and genitofemoral nerve blocks versus spinal anesthesia for outpatients undergoing long saphenous vein stripping surgery

Long saphenous vein stripping (LSVS) surgery is often used to treat varicose veins. We tested the hypothesis that femoral nerve block (FNB) with genitofemoral nerve infiltration provides sufficient analgesia and superior recovery characteristics to spinal anesthesia for LSVS procedures in the ambulatory setting. Thirty-six patients were randomized to receive FNB with 30 mL of 3% alkalinized chloroprocaine, and 32 patients received spinal anesthesia with 65 mg of 5% hyperbaric lidocaine. Data collected included patient demographics, time required for induction of and recovery from anesthesia, postoperative anesthesia complications, and patient report of pain severity after the operation. During a follow-up call, a blinded observer noted the onset of any complications, the requirement for analgesics, and the patients' satisfaction with the anesthetic technique. Patients in the FNB group had significantly faster recovery (P < 0.01) and lower incidences of pain (P < 0.05) and complications (P < 0.05) than the patients in the spinal group. All patients who received FNB indicated that they would choose this type of anesthesia in the future, whereas five (15%) patients in the spinal group would refuse spinal anesthesia in the future (P < 0.01). We conclude that FNB is an excellent anesthetic choice for LSVS.