Excellent Operating Conditions Research Articles

A comparative study on the effect of intrathecal nalbuphine and buprenorphine as an adjuvant to 0.5% hyperbaric bupivacaine in elective infraumbilical surgeries

: Subarachnoid blockade provides excellent operating conditions for lower abdominal, orthopedic, pelvic, urological, gynecological and lower extremity surgery. Most subarachnoid anesthetics are single shot injections and have a definite duration; hence opioids have been used along with local anesthetics in subarachnoid block to prolong its effect, duration, quality of analgesia and minimize the necessity of postoperative analgesics.: The primary objective of the study was to assess the onset and duration of sensory and motor blockade. The secondary objective of the study was to compare the hemodynamics, duration of postoperative analgesia and the complications encountered between the two groups.: A prospective randomized double-blinded study was done in 120 patients divided into two group with 60 in each group as group N and group B by computer generated random numbers. Group N received 0.5% Heavy Bupivacaine (3.2ml) + 0.6mg of Nalbuphine (0.3ml) to a total volume of 3.5 ml and Group B received 0.5% Heavy Bupivacaine (3.2ml) + 90µg of Buprenorphine (0.3 ml) to a total volume of 3.5 ml for spinal anesthesia. The differences between the groups were statistically analyzed with the Independent t test for continuous variables and Pearson’s chi-square test for categorical variables. Observations and results: The onset of sensory block (p=0.303) and motor block (p=0.510) was observed to be faster in group N when compared to group B with statistical insignificance, but the duration of both sensory block (p˂0.001) and motor block (p˂0.001) was more pronounced in group B when compared to group N with statistical significance. The duration of effective analgesia was more pronounced in group B (468.35±30.57 minutes) compared to group N (362.70±35.53 minutes).: The duration of the sensory and motor block with effective postoperative analgesia were more pronounced in buprenorphine compared to nalbuphine and hence intrathecal buprenorphine is a better alternative adjuvant to intrathecal nalbuphine in elective infraumbilical surgeries.

A Comparative Study of Epidural Butorphanol and Fentanyl as Adjuvants with 0.5% Bupivacaine for Postoperative analgesia in Lower Abdominal Surgeries

The pain is considered as sixth vital sign. Achieving adequate peri-operative and post -operative analgesia is of paramount importance to the anesthesiologist. This can be done by multiple approaches. One such technique is use of Epidural opioids. This study evaluates the analgesic efficacy of epidural fentanyl and butorphanol in lower abdominal surgeries for post -operative analgesia. Aims: To compare the degree of post-operative analgesia using butorphanol and fentanyl administered by epidural route. Settings and Design: Study setting: Tertiary care Hospital Study Design: A Prospective Double Blinded Randomised Clinical Study Methods and Material: A total of 60 Patients posted for elective lower abdominal surgeries were randomly selected for the study. The patients aged 20-60 years of ASA grade one and two posted for elective lower abdominal surgery were selected for the study. Drugs used were explained to the patients and also educated about Verbal numerical scale for assessment of pain. Patients were divided into two groups: Group A: receives Butorphanol 1mg mixed with 15 ml Bupivacaine 0.5%diluted upto 20 ml. Group B: receives Fentanyl 100 microgram mixed with 15 ml Bupivacaine 0.5% diluted upto 20 ml. Statistical analysis used: Statistical data was analysed using • Chi-square test • Student t-test (Paired and unpaired t-test) • A P value of < 0.05 is significant and >0.05 is not significant Results: The demographic variables were comparable in both groups. Both inj. Butorphanol 1 mg and Inj. Fentanyl 100 mcg given epidurally with Inj. Bupivacaine 0.5% as a single shot provided excellent operative conditions and satisfactory post-operative analgesia in both the groups. However, the duration of post-operative analgesia was much longer in the butorphanol group than Fentanyl group and was statistically significant. No serious side effects were noted in both groups. The method is economical, safe, convenient and acceptable and also poly pharmacy is avoided. Conclusions: Both fentanyl and butorphanol are safe and effective as epidural agents for postoperative analgesia with little side effects.

Science with the Fermi Large Area Telescope

The Fermi Gamma-ray Space Telescope started its science operations in August 2008. The Large Area Telescope (LAT) is the main instrument onboard Fermi. It is an imaging, wide field-of-view pair conversion telescope able to detect photons in the energy range from about 20 MeV up to the TeV region and it is still in excellent operating conditions after 14 years of observation. The Fermi-LAT is providing an increasingly detailed portrait of the Universe’s most extraordinary phenomena and plays a crucial role in the era of multi-messenger astrophysics. A selection of the most relevant scientific results obtained by the Fermi LAT telescope and some implications from indirect searches for dark matter will be presented.

A comparative study of fentanyl and tramadol as adjuvants to intrathecal hyperbaric bupivacaine 0.5% in caesarean deliveries

Background: Spinal anesthesia is a preferred method of anesthesia for surgery on elective caesarean section all over the world because of its efficacy, rapidity, reduction in blood loss, and protection against thromboembolic episodes. It offers excellent operating conditions like dense analgesia and adequate muscle relaxation. However it suffers from certain inherent disadvantages like fixed duration of anaesthesia and haemodynamic instability. Aims and Objectives: To evaluate the efficacy of intrathecal fentanyl and intrathecal tramadol as adjuvants to hyperbaric bupivacaine 0.5% in elective caesarean section patients in terms of duration of analgesia and intra-operative hemodynamic stability. Materials And Methods: This prospective, randomised, double blinded study was done over a period of 18 months. All the patients who underwent elective lower segment caesarean section under subarachnoid block between the age of 18-35yrs, body mass index between 18.5 to 24.9 Kg/m2 and belonging to ASA (American society of Anesthesiologists) Physical status II in Noida International Institute of Medical Sciences(NIIMS), Noida International University, Noida, UP, India. 62 patients undergoing elective caesarean section with 31 patients in each group.

Enriching terpinen-4-ol from tea tree (Melaleuca alternifolia) oil using vacuum fractional distillation: Effect of column and packings on the separation

Two types of columns, three types of packings, and four levels of column height were considered to investigate how column and packings affected the separation in the vacuum fractional distillation process of raw tea tree (Melaleuca alternifolia) oil (TTO). This study discussed those effects on purity, yield, and overall discovery to select the most excellent operating conditions for enriching terpinen-4-ol. After the experiments, the essential oil was successfully separated into two fractions, in which the second one composed mostly the main TTO constituent, terpinen-4-ol. The best result was achieved by conducting the distillation on a 300-mm Hempel column filled with small Fenske helices (10 mm × 2 mm i.d.) at the system pressure of 60 mmHg. GC/MS analysis showed an almost 2.5-fold increase in the content of terpinen-4-ol, from 39.23% to 95.77% after fractionation. Meanwhile, there was 75% of terpinen-4-ol successfully recovered from its parental oil. Hence, the vacuum fraction distillation could be an effective method to enrich the terpinen-4-ol content in TTO.

Online operating performance evaluation for the plant‐wide industrial process based on a three‐level and multi‐block method

AbstractProcess operating performance evaluation is of great significance both in theoretical research and practical application. Process operating performance evaluation is used to determine whether or not a production process is running in excellent operating conditions. When the production process is running in a non‐optimal state, non‐optimal reason tracing will be performed to find the reasons causing the non‐optimal running state of the process so that the process can quickly return to the optimal operating state. In this article, multiple working modes and plant‐wide industrial process characteristics are considered. To solve the above problems, a novel multiple three‐level multi‐block hybrid model based online operating performance evaluation approach is proposed. Under each working condition, a three‐level multi‐block model is established. Under the corresponding working mode, each block at the bottom level is evaluated first. Second, the blocks in the middle level are evaluated according to the evaluation results of the bottom level blocks. Finally, according to the evaluation results of the middle level blocks, the operating performance of the top level can be achieved. When non‐optimal operating performance occurs, a variable contribution‐based cause identification technique is developed to locate the variables leading to non‐optimal performance and provide operation strategies to bring the process back to optimal performance. At the end of the paper, the developed evaluation and non‐optimal cause identification approaches are explored in a gold hydrometallurgy process.

First Case of Deep Hypothermic Circulatory Arrest in Senegal (West Africa): Congenital Heart Disease Management

Background: Deep hypothermic circulatory arrest (DHCA) is an extracorporeal circulation (EC) technique used to correct complex congenital cardiac lesions. This technique ensures excellent operating conditions while reducing consequences of organ ischaemia, particularly of the brain. Griepp was the first to demonstrate in 1975, that the technique offered a practical and safe approach for aortic arch surgery. Case Report: Authors aim at reporting the practical conduct of DHCA’s first case performed in Dakar (Senegal) on a 30- month-old patient diagnosed with supracardiac total anomalous pulmonary venous connection (TAPVC). The cooling had started 8 minutes after CPB was initiated and continued while the surgeon dissected the pulmonary veins, the collector, and the innominate vein. After the establishment and the starting up of the cardiopulmonary bypass, circulatory arrest was performed at 18°C with 32 minutes of arrest time. The anastomosis between collector and posterior of the left atrium was achieved during a circulatory arrest. In the immediate postoperative period, patient showed episodes of hypothermia and biological bleeding. During her hospitalization, the patient developed a lung infection and PAH crisis, kept under control with antibiotic, diuretics, oxygen and sildenafil. Neurological, kidney, metabolic or ionic complications have not been observed. The patient stayed at the hospital for 32 days. Conclusion: DHCA technique is a common practice in developed countries. However, it can also be carried out in West Africa as evidenced by this clinical case. This prowess testifies a strengthening of our skills in EC technique; and also, the possibility of correcting complex congenital cardiac lesions.

Comparative evaluation of two different loading doses of dexmedetomidine with midazolam-fentanyl for sedation in vitreoretinal surgery under peribulbar anaesthesia.

Background and Aims:Midazolam-fentanyl (MDZ:FEN) combination has been routinely used for intravenous sedation in ophthalmic surgeries. Dexmedetomidine (DEX), a recent α2 adrenoreceptor agonist indicated for sedation for ophthalmic use at a loading dose of 0.5 μg/kg over 10 min, can cause deeper plane of sedation and surgeon dissatisfaction. Therefore, we proposed to evaluate the efficacy and safety of two different loading doses of DEX.Methods:In a prospective study, 60 patients aged 50-70 years, scheduled for retinal surgery under peribulbar block were divided equally to receive either MDZ:FEN or DEX 0.5 μg/kg (DEX full) or DEX 0.25 μg/kg (DEX half) loading dose over 10 min followed by titrated maintenance dose of DEX 0.25-0.4 μg/kg/h. Vital parameters, level of sedation (Ramsay Sedation Scale 1–6), effect on respiration and surgeon satisfaction were assessed at regular intervals. Surgeon satisfaction score (0–3) was noted.Results:‘DEX half’ group patients had predominantly stable haemodynamics, level 3 sedation and surgeon satisfaction score of 2–3 (good to excellent operating conditions). This group had no vomiting and no respiratory depression. ‘DEX full’ group had a higher incidence of bradycardia, hypotension, level 4 sedation (Ramsay Sedation Scale) and lower surgeon satisfaction. Incidence of nausea and vomiting was higher in MDZ:FEN group compared to other two groups.Conclusion:DEX 0.25 μg/kg loading dose over 10 min followed by titrated maintenance dose is an effective alternative to MDZ:FEN and provides controlled (level 3) sedation and stable haemodynamics maximising surgeon satisfaction. Avoiding narcotic analgesics with its associated post-operative nausea and vomiting is an additional benefit.

Deep neuromuscular block improves surgical conditions during laparoscopic hysterectomy: a randomised controlled trial.

The benefit of inducing deep neuromuscular block to improve laparoscopic surgical conditions is controversial. The goal of this study was to determine the depth of neuromuscular block needed to guarantee excellent operating conditions during laparoscopic hysterectomy. A randomised controlled trial. A single-centre study performed between February 2011 and May 2012. One hundred and two women of ASA physical status 1 or 2 gave consent to participate and were allocated randomly to one of two groups. Under desflurane general anaesthesia, patients in Group S (shallow block), neuromuscular blockade was induced by administration of rocuronium 0.45 mg kg-1 followed by spontaneous recovery or a rescue bolus dose of 5 mg if surgical conditions were unacceptable. In Group D (deep block), neuromuscular block was induced by administration of rocuronium 0.6 mg kg-1 and maintained by bolus doses of 5 mg if the train-of-four count exceeded two, using adductor pollicis electromyography. With a stable pneumoperitoneum (13 mmHg), the surgeon scored the quality of the surgical field every 10 min as excellent (1), good but not optimal (2), poor but acceptable (3) or unacceptable (4). The groups were compared using the Cochran-Armitage trend test. The level of neuromuscular blockade was recorded each time the surgical field score exceeded 1. For groups S and D, respectively, the maximum surgical field scores were 1 in 21 and 34 patients, 2 in 11 and 11 patients, 3 in 4 and 5 patients and 4 in 14 and 0 patients. A trend towards higher scores was demonstrated in group S (P < 0.001). Surgical field scores of 2, 3 and 4 occurred only when the train-of-four count was at least 1, 2 and 3, respectively. Inducing deep neuromuscular block (train-of-four count <1) significantly improved surgical field scores and made it possible to completely prevent unacceptable surgical conditions.

The effects of melatonin on anxiety and pain scores of patients, intraocular pressure, and operating conditions during cataract surgery under topical anesthesia

Aims:To evaluate the effects of melatonin premedication on anxiety and pain scores of patients, operating conditions, and intraocular pressure during cataract surgery under topical anesthesia.Materials and Methods:Sixty patients were randomly assigned to receive either sublingual melatonin 3 mg or placebo 60 min before surgery. Verbal anxiety scores and verbal pain scores, heart rate, systolic and diastolic blood pressure, intraocular pressure, and quality of operating conditions were recorded.Results:Melatonin significantly reduced the anxiety scores (median, interquartile range) from 5 and 5–3 to 3 and 2–4 after premedication and to 3 and 2–3 during surgery and to 0 and 0–1 postoperatively before discharge from the recovery room. There were significant differences between two groups in anxiety scores after premedication (95% CI 3–3.5; P = 0.023), intraoperatively (95% CI 2.5–3.5; P = 0.007), and postoperatively (95% CI 0.5–1; P = 0.007). The surgeon reported better quality of operating conditions in the melatonin group (P = 0.001). No significant difference in intraoperative and postoperative pain scores, intraocular pressure, heart rate, and systolic and diastolic blood pressure between two groups was recorded.Conclusion:Sublingual melatonin premedication for patients undergoing cataract surgery under topical anesthesia reduced the anxiety scores in patients and provided excellent operating conditions.

Transoral robotic surgery for head and neck cancer: A series of 17 cases

Transoral robotic surgery (TORS) is an innovative surgical technique indicated for resection of selected head and neck cancers. The authors report their experience and discuss the indications, advantages and disadvantages of this technique. Seventeen patients were operated by TORS in the Limoges University Hospital ENT department between March 2010 and January 2011. Tumour sites were the aryepiglottic fold (n=3), piriform sinus (n=2), lateral pharyngeal wall (n=3), posterior pharyngeal wall (n=2), base of tongue (n=3), vallecula (n=1), epiglottis (n=2) and arytenoid (n=2). One patient had two primary sites treated by TORS. This series comprised two stage I (11.7%), seven stage II (41.2%), six stage III (35.4%) and two stage IVa tumours (11.7%). Mean TORS set-up and operating times were 20.5 and 39.7 minutes, respectively. No major intraoperative complication was observed. One patient was reoperated on D5 for bleeding. Fifteen patients had clear surgical margins. Swallowing was restored on D2 for nine patients. The mean length of hospital stay was 10 days. Seven patients received adjuvant radiotherapy, seven patients were treated by chemoradiotherapy and three patients were submitted to simple clinical surveillance. TORS appears to provide new treatment options for head and neck cancers by extending the indications for endoscopic resection for selected cases of head and neck cancers. It allows effective cancer resection under excellent operating conditions with low morbidity and improved functional recovery. This new treatment modality needs to be evaluated in relation to other open surgery, endoscopic laser and chemoradiotherapy techniques.

Continuous cervical epidural analgesia for Isshiki type - I thyroplasty.

Thyroplasty is an operation on the upper airway to improve voice quality in patients with unilateral vocal cord paralysis. It is a difficult anaesthetic procedure that requires sharing the airway with the surgeon. We describe a good anaesthetic technique, which provides a safe airway with excellent operating conditions, using continuous cervical epidural anaesthesia and postoperative analgesia in three patients. The use of a regional anaesthetic technique provides excellent anaesthesia and analgesia while allowing the patient to phonate at the request of the surgeon intraoperatively.

Dexmedetomidine Sedation for Laryngeal Framework Surgery

Sedation for laryngeal framework surgery has lacked easy modulation between appropriate pain control, airway protection, and the alertness appropriate for vocal testing. Our objective was to determine whether dexmedetomidine hydrochloride could safely and effectively be used as the sole intravenous anesthetic agent in conjunction with local anesthesia for laryngeal framework procedures. We undertook a prospective review of 14 patients who underwent laryngeal framework surgery with dexmedetomidine anesthesia in 2004 and 2005. All dexmedetomidine doses, sedation levels, and vital signs, including blood pressure, heart rate, respiratory rate, and oxygen saturation level, were recorded every 15 minutes by the anesthesiologist throughout the duration of the procedures. Operative conditions were noted by the surgeon, focusing special attention on airway protection, patient arousability, and patient comfort. Dexmedetomidine sedation produced hemodynamic and respiratory values that were maintained near preoperative values, and overall pharyngeal-laryngeal integrity provided superior operating conditions for the patient and the operating surgeon. We believe that dexmedetomidine provides excellent sedative and operative conditions for awake laryngeal framework procedures. Coupled with local anesthesia, dexmedetomidine produced virtually no undesirable hemodynamic or respiratory effects, while allowing for adequate sedation the majority of the time. The operative conditions were markedly improved over those of previous standard monitored anesthesia regimens.

Orbital regional anesthesia.

Orbital regional anesthesia is a useful and safe modality for providing excellent operating conditions for the surgeon and painless, pleasant circumstances for the patient. It is especially suited for patients who are extremely sensitive and who could not tolerate topical anesthesia or a sub-Tenon's block without deep sedation. Both intraconal and extraconal techniques can be used safely and effectively if proper precautions are taken to enter the safest areas of the orbit and to avoid the vascular areas and the deep orbit where structures are tightly packed and thus more easily harmed. Thorough knowledge of orbital anatomy and understanding of the globe-orbit relationship of every patient are necessary to perform this form of regional anesthesia. In addition, knowledge of the effects and side effects of the anesthetics and adjuvants is also required.

Update on ambulatory anesthesia

MBULATORY surgery accounts for over 60% of all elective operative procedures performed in the United States. With the recent growth in major laparoscopic and office-based surgery, this percentage may increase to 70% in the future. When surgery is performed outside the conventional hospital environment, it can offer a number of advantages for patients, healthcare providers, third-party payers, and even hospitals. 1 Patients benefit from day-surgery because it minimizes costs, decreases separation from their home and family environment, reduces surgery waiting times, decreases their likelihood of contracting hospitalacquired infections, and appears to reduce postoperative complications. Compared to traditional hospital admissions, there is less pre- and postoperative lab testing and also a reduced demand for postoperative pain medication following ambulatory surgery. Unlike inpatient surgery, ambulatory surgery does not depend upon the availability of a hospital bed and may permit the patient greater flexibility in selecting the time of their elective operation. Furthermore, there is greater efficiency in the utilization of the operating and recovery rooms in the ambulatory setting, contributing to a decrease in the overall patient charges compared to similar hospital-based care. Comparison of general, spinal and local anesthesia The optimal anesthetic technique in the ambulatory setting would provide for excellent operating conditions, a rapid recovery, no postoperative side effects, and a high degree of patient satisfaction. In addition to increasing the quality and decreasing the costs of the anesthetic services, the ideal anesthetic technique would also improve operating room (OR) efficiency and provide for an early discharge home without side effects. Local anesthesia with iv sedation [so-called monitored anesthesia care (MAC)], spinal anesthesia, and general anesthesia are all commonly used anesthetic techniques for ambulatory surgery. However, opinions differ as to the best anesthetic technique for these surgical procedures. 2–15 Rather than simply

Ambulatory continuous interscalene brachial plexus blockade

Single-injection interscalene blocks provide excellent operating conditions, extended pain relief, and an advantageous side effect profile. As a result, anesthesiologists frequently perform them on an outpatient basis and are likely to discharge them insensate after using a long-acting local anesthetic. 1 However, a disadvantage to this practice is the regression of analgesia that often occurs after 12 to 24 hours when a single-injection technique is used. A significant portion of the pain relief and narcotic sparing is reduced when the block recedes rapidly after discharge. Depending on standard oral pharmacologic management for this transition is often insufficient to achieve the dense level of pain relief provided by the initial dose of local anesthetic. For shoulder surgery, this often results in severe pain. This is especially true for major shoulder surgery that typically requires a hospital stay for IV opioids. Ambulatory continuous interscalene brachial plexus block (CISB) can provide a solution for the rapid resolution of analgesia after a single injection block. This is especially true for major shoulder, clavicle, and humerus surgery. More importantly, CISB also provides continuous site-specific local anesthetic delivery, resulting in intense surgical anesthesia, effective long-term postoperative analgesia, reduced opioid requirements, an enhanced side effect profile, and may facilitate rehabilitation. Even relatively minor surgery, such as shoulder arthroscopy or rotator cuff repair, may benefit from this technique.

Inhalation versus intravenous anaesthesia for day surgery

Opinion is often fiercely divided over the relative merits of intravenous or inhaled anaesthesia for day case procedures. Advocates of intravenous anaesthesia claim superior recovery and minimal side effects, yet inhalational agents remain popular and are widely used for their excellent operative conditions and low costs. This review will consider the recent evolution in both inhalation and intravenous anaesthesia and will describe what are probably the optimal techniques for the delivery of each. Possible advantages and disadvantages of these approaches will be discussed and the outcomes examined. In reality, recovery characteristics are very similar with either of the two techniques and where differences do exist, they are of minimal importance. Costs may differ, but again the differences are small and frequently absorbed within the far greater overall costs of the procedure. Postoperative nausea and vomiting (PONV) is the most contentious outcome and this will be examined in some detail. While most evidence would favour intravenous anaesthesia in this respect, the magnitude of the advantage may be overestimated and strategies for reducing side effects after inhalation anaesthesia to acceptable levels will be presented. Finally, the future of day case anaesthesia will be considered, with the unfortunate conclusion that the supply of exciting new anaesthetic agents appears to be exhausted, at least for the present.

Airway Management for Pediatric Esophagogastroduodenoscopy Using an Endoscopy Mask

To the Editor: The safety of deep sedation for esophagogastroduodenoscopy (EGD) in pediatric patients has been well established (1). Using IV anesthetics to maintain deep sedation with spontaneous ventilation is associated with about a 3% incidence of hemoglobin-oxygen desaturation as a result of apnea, upper airway obstruction, or laryngospasm (2). Using a specially designed Endoscopy Mask (International Medical Development, Inc., Park City, Utah), we have been able to deeply anesthetize pediatric patients for EGD while maintaining control of the airway throughout the procedure. In our experience with 15 pediatric patients (3 months to 17 years), anesthesia was tolerated without any instances of respiratory complications or hemoglobin-oxygen desaturation. Excellent operating conditions were created for the endoscopists using sevoflurane or propofol for anesthetic maintenance. The Endoscopy Mask has an elastic diaphragm with a 3-mm diameter opening designed for the passage of a fiberoptic bronchoscope (Fig. 1). This diaphragm can be modified for the purpose of EGD by enlarging the diameter to 6 mm (Fig. 2).Figure 1: The Endoscopy Mask (International Medical Development, Inc., Park City, Utah).Figure 2: An endoscope inserted through the Endoscopy Mask during upper endoscopy on a pediatric patient.This technique allows the anesthesiologist to assist ventilation during periods of shallow breathing or hemoglobin-oxygen desaturation. The Endoscopy Mask permits the delivery of a higher concentration of oxygen to the patient than a nasal cannula. Positive pressure ventilation can be employed when necessary. We would like to acknowledge the assistance of Dr. Irene Osborn, Associate Clinical Professor, Department of Anesthesiology, Mount Sinai School of Medicine. Robert Y. Rauch, MD Craig E. Brener, MD

Intravenous anaesthesia for laser surgery of the airway in children with recurrent laryngeal papillomatosis.

Juvenile laryngeal papillomatosis is a recurrent condition that presents a number of challenges to the anaesthetist: varying degrees of airway obstruction, the child's airway is shared and safe use of a laser is required. As well as the usual considerations of laser use, the child's larynx should move as little as possible.At present the treatment of choice is laser vapourisation of the papillomata. Several anaesthetic techniques have been described, including jet ventilation, intermittent intubation, apnoeic techniques and insufflation of volatile gases with or without spontaneous ventilation (1). Endotracheal intubation has been associated with seeding of the papillomata into the distal airway.The technique at the Birmingham Children's Hospital for the past 5 years is described; it is based upon deep intravenous anaesthesia with spontaneous ventilation, supplemented by topical lignocaine. Children with significant stridor at rest are induced with volatile/oxygen mixture, otherwise the method of induction is determined by child and anaesthetist. Once the child is deeply anaesthetised the larynx of the child is sprayed with lignocaine (4 mg·kg−1). The volatile agent is then discontinued and anaesthesia is provided by an intravenous infusion of propofol and alfentanil running at 10–20 mg·kg−1·hr−1 and 20–30 mcg·kg−1·hr−1 respectively. Oxygen enriched air is delivered into the pharynx via a nasopharyngeal airway. The oxygen saturation of the child is maintained at 95–97% in order to reduce the risk of ignition of the inspired oxygen by the laser. The larynx of the child is placed in suspension to produce an open airway. Depth of anaesthesia is determined primarily by the child's ventilatory pattern (adrenaline is used topically by the surgeon for haemostasis and interferes with the child's heart rate and blood pressure). End tidal CO2 concentration was measured intermittently for the first few cases, but was always found to be in the normal range. After completion of surgery (usually 15–90 min) the child is placed in the recovery position and allowed to recover.Over the past 5 years at our hospital 11 children have undergone 112 procedures. There have been no airway complications. Recovery is not prolonged (time to spontaneous eye opening about 10–15 min). This simple technique allows excellent surgical operating conditions with unimpeded visualisation of the barely mobile larynx. There is no pollution of the operating theatre or surgeon by volatile agents. The technique is now routinely used for all microlaryngeal surgery.

Role of non-opioid analgesics in ambulatory anesthesia

T he optimal anesthetic technique in the ambulatory setting would provide for excellent operating conditions, a rapid recovery, no postoperative side effects, and a high degree of patient satisfaction. In addition to improving the quality of care and decreasing the costs of the anesthetic services, the ideal anesthetic technique would also improve operating room (OR) efficiency and provide for an early discharge home. Local infiltration anesthesia with sedation (so-called monitored anesthesia care [MAC]), spinal anesthesia, and general anesthesia are all commonly used for ambulatory surgery. However, opinions differ as to the best anesthetic technique for these surgical procedures.l-14 In the current cost-conscious environment, it is important to examine the impact of anesthetic techniques on the recovery process after ambulatory surgery because prolonged recovery times and perioperative complications increase the cost of patient care. In addition, the level of patient satisfaction with their care is improved when the anesthetic technique chosen for the procedure is associated with a low incidence of postoperative side effects. For example, routine use of prophylactic antiemetic drugs during general anesthesia has been found to increase patient satisfaction in at risk outpatient surgical populations. 15 The use of effective peripheral local anesthetic block or infiltration/instillation techniques to supplement both MAC and general anesthesia is the key to providing successful non-opioid anesthesia in the ambulatory setting (Table 1). For example, the use of a simple ilioinguinal-hypogastric nerve block decreases postoperative pain after inguinal hernia repair procedures irrespective of the anesthetic technique. 3,16,17 The time required to achieve a state of homereadiness is influenced by a wide variety of surgical and anesthetic factors. 18'19 However, the major contributors to delays in discharge after ambulatory surgery are nausea, vomiting, dizziness, pain, and prolonged sympathetic and/or motor blockade. Although the incidence of postoperative nausea and vomiting can be decreased by the use of proTable 1. Commonly Used Techniques for Administering Local Anesthesia for Ambulatory Surgery