Ambulatory anesthesia advances into the new millennium

Efficacy and Safety of Flexible Laryngeal Mask Ventilation in Otologic Surgery: A Retrospective Analysis

Background

Flexible laryngeal mask airways (FLMAs) ventilation have been widely used as airway devices during general anesthesia, especially in otologic surgery. However, the current literature reports that the clinical success and failure rates for FLMA usage are quite different, and there remains a paucity of data regarding factors associated with FLMA failure and complications related to FLMA usage.

Purpose

To evaluate the success and failure rates of FLMA usage in otologic surgery, the factors associated with FLMA failure and complications related to FLMA usage.

Patients and Methods

All patients who underwent otologic surgery, including middle ear and mastoid procedures, under general anesthesia at a large tertiary general hospital from 2015 to 2019 were reviewed. The primary outcome was the FLMA failure rate, defined as any airway event requiring device removal and tracheal intubation, including primary and secondary failure. The secondary outcomes were specific clinical factors, including patient sex, age, weight, American Society of Anesthesiologists (ASA) classification, body mass index (BMI) and duration of surgery, which were analyzed as related risk factors.

Results

Among 5557 patients with planned FLMA use, the final success rate was 98.5%. Sixty-seven percent of the failures occurred during initial introduction of the FLMA, 8% occurred after head and neck rotation, and 25% occurred during the procedures. Two independent clinical factors associated with FLMA failure were male sex and age. Respiratory complications were observed in 0.61% of patients, and the rate of severe nerve and tissue damage associated with FLMA use was 0.05.

Conclusion

This study demonstrates a high success rate of 98.5% for FLMA use in adults undergoing otologic surgery with rare adverse airway events and injuries complications. Two independent risk factors require attention and thorough and accurate management is necessary for every clinician.

R, Jayanthi A. A Comparative Study of Isobaric 1% Chloroprocaine With 0.5% Isobaric Bupivacaine for Ureteroscopic Lithotripsy Under Spinal Anaesthesia: A Prospective Randomised Study

Introduction

Day-care surgery has become an immensely popular modality of treatment throughout the globe. Ureteroscopic lithotripsy (URSL) surgery is commonly performed on a day-care basis, and the duration of surgery ranges from 15 minutes to 45 minutes. URSL is routinely done under spinal anaesthesia. Spinal anaesthesia with conventional drugs has its problems like delayed regression and urinary retention, necessitating a longer hospital stay, thereby increasing the time and resources needed. For day-care surgery, short-acting local anaesthetics have a quicker onset with fewer side effects, and drugs that ensure quicker hospital discharge are more often preferred over long-acting anaesthetics. For spinal anaesthesia, we planned to perform a randomised prospective study to compare the effectiveness of 40 mg of preservative-free 1% chloroprocaine over 10 mg of plain 0.5% isobaric bupivacaine.

Materials and method

After obtaining clearance from the institute’s ethical committee and written informed consent from the patients, 64 patients between the ages of 18 and 50 years of either sex belonging to American Society of Anesthesiologists (ASA) 1 and 2 scheduled for URSL surgery were included in our study. They were randomised using a computer-generated sealed envelope technique into two groups. Group C received 4 ml of 1% isobaric chloroprocaine, and group B received 2 ml of 0.5% isobaric bupivacaine in the intrathecal space. The primary outcome was to compare the in-hospital time among both groups. Our secondary outcomes were the onset time of motor and sensory blocks, the duration of the blocks, time to unaided ambulation and voiding, the need for an overnight stay, and the side effects like postoperative nausea and vomiting (PONV), and urinary retention. The data were analysed using the unpaired t-test and chi-square test and calculated by SPSS 20.0 software version (IBM Corp., Armonk, NY).

Results

Final analyses were done among 60 patients. In-hospital time was significantly lower in group C as compared to group B (p<0.05). The onset time of sensory and motor blockade was significantly lower in group C as compared to group B (p<0.005). The duration of sensory and motor blockade was significantly less in group C as compared to group B (p<0.005). The time for unaided voiding and ambulation was less in group C as compared to group B. The need for an overnight stay was only needed in group B. The incidence of PONV and urinary retention was higher in group B.

Conclusion

In URSL surgery, the use of intrathecal 1% isobaric chloroprocaine 40 mg resulted in a reduced hospital stay time as compared to the use of intrathecal 10 mg of 0.5% isobaric bupivacaine. Also, it resulted in a significantly faster onset and faster regression of the block, less duration of the blockade, shorter time to ambulation and micturition, and a requirement for an overnight stay when compared with isobaric spinal bupivacaine.

Is Day Care Tonsillectomy a Safe Procedure?

Tonsillectomy with or without adenoidectomy is the commonest procedure performed by an otolaryngologist. It has been performed as an in-patient procedure. To present our experience of 15 years of day care tonsillectomy with or without adenoidectomy and to assess the safety of tonsillectomy as a day care procedure. Design: retrospective study. A retrospective study of all day care tonsillectomies with or without adenoidectomies operated at a Secondary care ENT Hospital from 2002 to 2016 has been carried out. In last 15 years, we have operated 1207 tonsillectomies with or without adenoidectomies as a day care procedure. Postoperatively, the patients were discharged after observing for 6 to 8 h. Out of 1207 patients, 3 patients required readmission due to bleeding and 5 due to pain. Hence the overall readmission rate following tonsillectomy was 8/1027, which equals to 0.778 percent. Two patients with postoperative bleeding within 6 h were taken up for exploration and control of hemostasis. One patient of secondary haemorrhage was managed conservatively. None of the patients required blood transfusion. Day care tonsillectomy with or without adenoidectomy is a safe procedure as long as the patients are carefully selected. It is also cost effective. Level of evidence: Level 4.

Perioperative Care of Elderly Surgical Outpatients

The ambulatory setting offers potential advantages for elderly patients undergoing elective surgery due to the advancement in both surgical and anesthetic techniques resulting in quicker recovery times, fewer complications, higher patient satisfaction, and reduced costs of care. This review article aims to provide a practical guide to anesthetic management of elderly outpatients. Important considerations in the preoperative evaluation of elderly outpatients with co-existing diseases, as well as the advantages and disadvantages of different anesthetic techniques on a procedural-specific basis, and recommendations regarding the management of common postoperative complications (e.g., pain, postoperative nausea and vomiting [PONV], delirium and cognitive dysfunction, and gastrointestinal dysfunction) are discussed. The role of anesthesiologists as perioperative physicians is important for optimizing surgical outcomes for elderly patients undergoing ambulatory surgery. The implementation of high-quality, evidence-based perioperative care programs for the elderly on an ambulatory basis has assumed increased importance. Optimal management of perioperative pain using opioid-sparing multimodal analgesic techniques and preventing PONV using prophylactic antiemetics are key elements for achieving enhanced recovery after surgery.

Anesthesia for ambulatory surgery

Ambulatory anesthesia allows quick recovery from anesthesia, leading to an early discharge and rapid resumption of daily activities, which can be of great benefit to patients, healthcare providers, third-party payers, and hospitals. Recently, with the development of minimally invasive surgical techniques and short-acting anesthetics, the use of ambulatory surgery has grown rapidly. Additionally, as the indications for ambulatory surgery have widened, the surgical methods have become more complex and the number of comorbidities has increased. For successful and safe ambulatory anesthesia, the anesthesiologist must consider various factors relating to the patient. Among them, appropriate selection of patients and surgical and anesthetic methods, as well as postoperative management, should be considered simultaneously. Patient selection is a particularly important factor. Appropriate surgical and anesthetic techniques should be used to minimize postoperative complications, especially postoperative pain, nausea, and vomiting. Patients and their caregivers should be fully informed of specific care guidelines and appropriate responses to emergency situations on discharge from the hospital. During this process, close communication between patients and medical staff, as well as postoperative follow-up appointments, should be ensured. In summary, safe and convenient methods to ensure the patient's return to function and recovery are necessary.

Techniques to Optimize Multimodal Analgesia in Ambulatory Surgery

PURPOSE OF REVIEW

Ambulatory surgery has grown in popularity in recent decades due to the advancement in both surgical and anesthetic techniques resulting in quicker recovery times, fewer complications, higher patient satisfaction, and reduced costs of care. We review common approaches to multimodal analgesia.

RECENT FINDINGS

A multimodal approach can help reduce perioperative opioid requirements and improve patient recovery. Analgesic options may include NSAIDs, acetaminophen, gabapentinoids, corticosteroids, alpha-2 agonists, local anesthetics, and the use of regional anesthesia. We highlight important aspects related to pain management in the ambulatory surgery setting. A coordinated approach is required by the entire healthcare team to help expedite patient recovery and facilitate a resumption of normal activity following surgery. Implementation and development of standardized analgesic protocols will further improve patient care and outcomes.

An update on pain management for elderly patients undergoing ambulatory surgery

PURPOSE OF REVIEW

The aim of this review is to provide an overview of the drugs and techniques used for multimodal postoperative pain management in the older population undergoing surgery in the ambulatory setting.

RECENT FINDINGS

Interest has grown in the possibility of adding adjuncts to a single shot nerve block in order to prolong the local anesthetic effect. The rapid and short-acting local anesthetics for spinal anesthesia are potentially beneficial for day-case surgery in the older population because of shorter duration of the motor block, faster recovery, and less transient neurologic symptoms. Another recent advance is the introduction of intravenous acetaminophen, which can rapidly achieve rapid peak plasma concentration (<15 min) following infusion and analgesic effect in ∼5 min with a duration of action up to 4 h.

SUMMARY

The nonopioid analgesic therapies will likely assume an increasingly important role in facilitating the recovery process and improving the satisfaction for elderly ambulatory surgery patients. Strategies to avoid the use of opioids and minimize opioid-related side-effects is an important advance as we expand on the use of ambulatory surgery for the aging population.

Preoperative rTMS Language Mapping in Speech-Eloquent Brain Lesions Resected Under General Anesthesia: A Pair-Matched Cohort Study

OBJECTIVE

The value of preoperative repetitive transcranial magnetic stimulation (rTMS) language mapping for function preservation in surgery of speech-eloquent lesions under general anesthesia remains to be determined.

METHODS

We prospectively enrolled 20 consecutive right-handed patients with a malignant, left-sided perisylvian language-eloquent brain tumor. All patients were subjected to surgical resection under general anesthesia guided by preoperative rTMS language mapping (rTMS group, 2014-2016). A matched-pair analysis with 20 patients who also underwent surgical resection under general anesthesia in the pre-rTMS era (pre-rTMS group, 2009-2013) was performed. Language performance status was ranked from grade 0 to grade 3 (none, mild, medium, severe).

RESULTS

Rates of gross total resection, tumor residual, and complications were equal in both groups. Duration of surgery (P = 0.039) and inpatient stay (P = 0.001) were significantly shorter in the rTMS group. Preoperatively, 14 patients in the rTMS and 13 patients in the pre-rTMS group had language deficits (P = 0.380). One week after surgery, 8/14 patients (57.1%) in the rTMS group but only 1/13 patients (7.7%) in the pre-rTMS group experienced improvement of language performance status (P = 0.013). At 6 weeks follow-up, language performance status was significantly better in the rTMS group (P = 0.048). However, at 3 months follow-up, the rTMS and pre-rTMS groups showed an equal language performance status.

CONCLUSIONS

Implementation of preoperative rTMS language mapping seems to provide a favorable early language outcome in patients undergoing surgical resection of language-eloquent lesions under general anesthesia.

Neurocognitive Function Surrounding the Resection of Frontal WHO Grade I Meningiomas: A Prospective Matched-Control Study

OBJECTIVE

Patients with intracranial meningiomas can experience neurocognitive dysfunctions in specific cognitive domains depending on tumor location and size. The literature regarding cognitive function surrounding the resection of frontal meningiomas is sparse.

METHODS

We performed a prospective matched-control study to investigate the cognitive performance of frontal meningioma patients undergoing resection. The neurocognitive status 1 week and 2 months after resection was compared with the preoperative status and matched-controls. Matching was performed for age, sex, handedness, education, and profession. An extensive test battery was used to assess perceptual speed, executive function, visual-spatial and verbal working memory, short- and long-term memory, verbal fluency, fluid intelligence, anxiety, and depression.

RESULTS

Twelve patients with frontal World Health Organization grade I meningioma and 12 matched-controls underwent cognitive testing. Macroscopically, complete removal was achieved in all cases. Comparison of patients and controls revealed significant cognitive impairments in perceptual speed, executive function, short-term memory, and verbal fluency preoperatively and postoperatively. At 2 months' follow-up, perceptual speed and verbal fluency were still significantly impaired, whereas executive function and short-term memory were equal to that in the control group. None of the patients experienced cognitive deterioration after surgical therapy.

CONCLUSION

Patients with frontal meningiomas display preoperative and postoperative deficits in perceptual speed, executive function, short-term memory, and verbal fluency. The risk for cognitive deterioration owing to surgical resection is low. Within the first two months after surgery, executive function and short-term memory appear to recover.

[Unilateral spinal anesthesia : Literature review and recommendations]

Unilateral spinal anesthesia is a cost-effective and rapidly performed anesthetic technique. An exclusively unilateral block only affects the sensory, motor and sympathetic functions on one side of the body and offers the advantages of a spinal block without the typical adverse side effects seen with a bilateral block. The lack of hypotension, in particular, makes unilateral spinal anesthesia suitable for patients with cardiovascular risk factors e. g. aortic valve stenosis or coronary artery disease. Increasing numbers of surgical procedures are now being performed on an outpatient basis. Until now, spinal anesthesia has been considered unsuitable for this, not only because of the high incidence of intraoperative hypotension and postoperative urinary retention but also because of the prolonged postoperative stay before home discharge. This is not the case with unilateral spinal anesthesia: motor function returns rapidly, the incidence of urinary retention is extremely low, and patients are usually eligible for home discharge sooner than after bilateral spinal anesthesia or general anesthesia. The success of the technique depends on a number of factors. In addition to the local anesthetic, its concentration and dose, and the baricity of the injected solution, the shape of the spinal needle, the injection speed, the patient's position during injection, and the time the patient remains in this position after injection are equally important parameters. A number of intrathecally applied adjuvant drugs are used to give a more intense and/or longer-lasting block. For this review, we collated the published data on unilateral spinal anesthesia from journals with an impact factor greater than 1.0 and defined an optimized method for performing the technique. In order to achieve an exclusively unilateral block one should use 0.5 % hyperbaric bupivacaine injected at a rate of 0.33 ml/min or slower. During the injection and the following 20 min the patient should lie in the lateral decubitus position on the side intended for surgery with knees drawn to the chest. An injection of 5 mg (1 ml) hyperbaric bupivacaine 0.5 % provides an hour-long block to T 12, and a dose of 7.5 to 10 mg (1.5-2.0 ml) extends the block to T 6. Adding clonidine (0.5 to 1.0 µg/kg BW) to the injection prolongs the duration of the block to approximately two to three hours. During the 20-minute fixation period, the cephalad spread of the block can be influenced to a certain extent by raising or lowering the head of the table.

Laryngeal mask placement in a teaching institution: analysis of difficult placements

Background: Laryngeal mask airway (LMA) placement is now considered a common airway management practice. Although there are many studies which focus on various airway techniques, research regarding difficult LMA placement is limited, particularly for anesthesiologist trainees. In our retrospective analysis we tried to identify predictive factors of difficult LMA placement in an academic training program.

Methods: This retrospective analysis was derived from a research airway database, where data were collected prospectively at the Memorial Hermann Hospital, Texas Medical Center, Houston, TX, USA, from 2008 to 2010. All non-obstetric adult patients presenting for elective surgery requiring general anesthesia, were enrolled in this study: anesthesiology residents primarily managed the airways. The level of difficulty, number of attempts, and type of the extraglottic device placement were retrieved.

Results: Sixty-nine unique Laryngeal Mask Airways (uLMAs) were utilized as a primary airway device. Two independent predictors for difficult LMA placement were identified: gender and neck circumference. The sensitivity for one factor is 87.5% with a specificity of 50%. However with two risk factors, the specificity increases to the level of 93% and the sensitivity is 63%.

Conclusion: In a large academic training program, besides uLMA not been used routinely, two risk factors for LMA difficulty were identified, female gender and large neck circumference. Neck circumference is increasingly being recognized as a significant predictor across the spectrum of airway management difficulties while female gender has not been previously reported as a risk factor for difficult LMA placement.

New medications and techniques in ambulatory anesthesia

Novel anesthetic and analgesic agents are currently under development or investigation to improve anesthetic delivery and patient care. The pharmacokinetic and analgesic profiles of these agents are especially tailored to meet the challenges of rapid recovery and opioid minimization associated with ambulatory anesthesia practice.

Anesthesia methods in laser resurfacing

Laser resurfacing technology offers the ability to treat skin changes that are the result of the aging process. One of the major drawbacks of laser resurfacing technologies is the pain associated with the procedure. The methods of anesthesia used in laser resurfacing to help minimize the pain include both noninvasive and invasive procedures. The noninvasive procedures can be divided into topical, cryoanesthesia, and a combination of both. The invasive methods of anesthesia include injected forms (infiltrative, nerve blocks, and tumescent anesthesia) and supervised anesthesia (monitored anesthesia care and general anesthesia). In this review, the authors summarize the types of anesthesia used in laser resurfacing to aid the provider in offering the most appropriate method for the patient to have as painless a procedure as possible.

Pain management after surgery: a brief review

Proper pain management, particularly postoperative pain management, is a major concern for clinicians as well as for patients undergoing surgery. Although many advances have been made in the field of pain management, particularly during the past decades, not all patients achieve complete relief from postoperative pain. In this paper, we have emphasized the importance of postoperative analgesia and discussed the new developments in this field.

A comparison of three different target-controlled remifentanil infusion rates during target-controlled propofol infusion for oocyte retrieval

OBJECTIVE

To evaluate the effects of three different target-controlled remifentanil infusion rates during target-controlled propofol infusion on hemodynamic parameters, pain, sedation, and recovery score during oocyte retrieval.

METHODS

Sixty-nine women were scheduled for oocyte retrieval. Target-controlled propofol infusion at an effect-site concentration of 1.5 μg/mL was instituted. The patients were randomly allocated to receive remifentanil at an effect-site concentration of either 1.5 (group I, n = 23), 2 (group II, n = 23) or 2.5 ng/mL (group III, n = 23). Hemodynamic variables, sedation, pain, the Aldrete recovery score, and side effects were recorded.

RESULTS

Hemodynamic variables, sedation and pain scores and the number of patients with the maximum Aldrete recovery score 10 min after the procedure were comparable among the groups. The number of patients in group III with the maximum Aldrete recovery score 5 min after the procedure was significantly lower than that in groups I and II. One patient in group II and one patient in group III suffered from nausea.

CONCLUSION

Similar pain-free conscious sedation conditions without significant changes in hemodynamic parameters were provided by all three protocols. However, target controlled infusion of remifentanil at 1.5 or 2 ng/mL proved superior at providing early recovery compared to 2.5 ng/mL.

Fast-track anesthetic techniques for ambulatory surgery

PURPOSE OF REVIEW

Improving perioperative efficiency and throughput has become increasingly important in facilitating the fast-track recovery process following ambulatory surgery. This review focuses on the important role played by the anesthesiologist as a perioperative physician in fast-track ambulatory surgery.

RECENT FINDINGS

A literature review of more than 200 peer-reviewed publications was used to develop evidence-based recommendations for optimizing recovery following ambulatory anesthesia. The choice of anesthetic technique should be tailored to the needs of the patient as well as the type of surgical procedure being performed in the ambulatory setting. The anesthetic decisions made by the anesthesiologist, as a key perioperative physician, are of critical importance in developing a successful fast-track ambulatory surgery program.

SUMMARY

The pivotal role played by the anesthesiologist as the key perioperative physician in facilitating the recovery process has assumed increased importance in the current outpatient fast-track recovery environment. The choice of premedication, anesthetic, analgesic and antiemetic drugs, as well as cardiovascular, hormonal and fluid therapies, can all influence the ability to fast-track outpatients after ambulatory surgery.

Postoperative pain treatment for ambulatory surgery

One of the most significant changes in surgical practice during the last two decades has been the growth of ambulatory surgery. Adequate postoperative analgesia is a prerequisite for successful ambulatory surgery. Recent studies have shown that large numbers of patients suffer from moderate to severe pain during the first 24-48 hr. The success of fast-tracking depends to a considerable extent on effective postoperative pain management routines and the cost saving of outpatient surgery may be negated by unanticipated hospital admission for poorly treated pain. Depending on the intensity of postoperative pain current management includes the use of analgesics such as paracetamol, NSAIDs including coxibs and tramadol as single drugs or in combination as part of balanced (multimodal) analgesia. However, in the ambulatory setting many patients suffer from pain at home in spite of multimodal analgesic regimens. Sending patients home with perineural, incisional, and intra-articular catheters is a new and evolving area of postoperative pain management. Current evidence suggests that these techniques are effective, feasible and safe in the home environment if appropriate patient selection routines and organization for follow-up are in place.

The Role of the Anesthesiologist in Fast-Track Surgery: From Multimodal Analgesia to Perioperative Medical Care

BACKGROUND

Improving perioperative efficiency and throughput has become increasingly important in the modern practice of anesthesiology. Fast-track surgery represents a multidisciplinary approach to improving perioperative efficiency by facilitating recovery after both minor (i.e., outpatient) and major (inpatient) surgery procedures. In this article we focus on the expanding role of the anesthesiologist in fast-track surgery.

METHODS

A multidisciplinary group of clinical investigators met at McGill University in the Fall of 2005 to discuss current anesthetic and surgical practices directed at improving the postoperative recovery process. A subgroup of the attendees at this conference was assigned the task of reviewing the peer-reviewed literature on this topic as it related to the role of the anesthesiologist as a perioperative physician.

RESULTS

Anesthesiologists as perioperative physicians play a key role in fast-track surgery through their choice of preoperative medication, anesthetics and techniques, use of prophylactic drugs to minimize side effects (e.g., pain, nausea and vomiting, dizziness), as well as the administration of adjunctive drugs to maintain major organ system function during and after surgery.

CONCLUSION

The decisions of the anesthesiologist as a key perioperative physician are of critical importance to the surgical care team in developing a successful fast-track surgery program.

Ambulatory anesthesia and the lack of consensus among Canadian pediatric anesthesiologists: a survey

BACKGROUND

The purpose of this study was to assess the current selection criteria for outpatient surgery in children among Canadian pediatric anesthesiologists.

METHODS

A survey specifying 20 different medical situations was sent to 120 members of the Canadian Pediatric Anesthesia Society. Members were asked to indicate if they agreed or refused to provide anesthesia for children with one or more clinical condition or symptoms. Consensus was defined as a >70% majority opinion.

RESULTS

Sixty-four pediatric anesthesiologists replied (53.3%). For 13 conditions there was no consensus among members. Seven scenarios resulted in a consensus of either providing or not providing anesthesia in an outpatient setting. The majority of members would agree to provide anesthesia for the following scenarios: (i) an asymptomatic child with recurrent otitis media, rectal temperature of 38 degrees C; (ii) the same child with chronic nasal discharge for bilateral myringotomy and tube placement; (iii) an asymptomatic child with sickle-cell disease (SCD) for cast change; (iv) an asymptomatic child with asthma and fever for bilateral myringotomy and tube placement (BMT); (v) a morbidly obese child with congested nose for BMT; and (vi) a child with well controlled insulin dependent diabetes mellitus for magnetic resonance imaging (MRI). Most members would refuse to provide outpatient anesthesia in an asymptomatic child with SCD for tonsillectomy.

CONCLUSION

Further studies are needed to establish evidence-based medicine to support guidelines that would allow one to select children safely for ambulatory surgery.

Which muscle relaxants should be used in day surgery and when

PURPOSE OF REVIEW

After myorelaxants, myalgia and residual curarization may complicate recovery. Local anaesthesia and minimally invasive airway management make myorelaxants disputable in many outpatient procedures; nevertheless, neuromuscular blockade may be necessary to facilitate intubation or maintain muscle relaxation. Agent selection criteria are discussed.

RECENT FINDINGS

Reduced hospital time is not associated with central neuraxial or peripheral nerve block. To reduce the risk for residual block, neuromuscular monitoring is mandatory. Use of reversal agents should not be restricted, although studies have shown higher incidence of postoperative nausea and vomiting following their use. Higher succinylcholine dosage is followed by lower incidence of myalgia. The relationship between fasciculation and myalgia is unclear. Sodium channel blockers or nonsteroidal antiinflammatory drugs may prevent myalgia. Sugammadex functions as a chelating agent.

SUMMARY

Ear-nose-throat, open eye surgery and laparoscopy may demand myoresolution. Regional and minimally invasive anaesthesia are alternative solutions. Central and peripheral nerve blocks are associated with increased induction time, reduced pain scores, and decreased need for analgesics. Central neuraxial block, however, is associated with prolonged outpatient unit stay. Bad intubating conditions may cause pharyngo-laryngeal complications: the decision to avoid myorelaxants for tracheal intubation appears illogical. Incidence of postoperative residual curarization remains very high. Sugammadex offers new perspectives.

The changing role of non-opioid analgesic techniques in the management of postoperative pain

Given the expanding role of ambulatory surgery and the need to facilitate an earlier hospital discharge, improving postoperative pain control has become an increasingly important issue for all anesthesiologists. As a result of the shift from inpatient to outpatient surgery, the use of IV patient-controlled analgesia and continuous epidural infusions has steadily declined. To manage the pain associated with increasingly complex surgical procedures on an ambulatory or short-stay basis, anesthesiologists and surgeons should prescribe multimodal analgesic regimens that use non-opioid analgesics (e.g., local anesthetics, nonsteroidal antiinflammatory drugs, cyclooxygenase inhibitors, acetaminophen, ketamine, alpha 2-agonists) to supplement opioid analgesics. The opioid-sparing effects of these compounds may lead to reduced nausea, vomiting, constipation, urinary retention, respiratory depression and sedation. Therefore, use of non-opioid analgesic techniques can lead to an improved quality of recovery for surgical patients.

Treatment of postoperative pain for burn patients with intravenous analgesia in continuous perfusion using elastomeric infusors

INTRODUCTION

Postoperative pain after surgery with patients suffering from burns tends to be moderate or severe, and its treatment requires a combination of high-strength analgesics (opioids) with others having different action mechanisms according to the concept of multimodal analgesia.

AIMS

In this article we propose the use of continuous intravenous analgesia with morphine using elastomeric infusors at fixed dose for the treatment of this kind of pain. An evaluation is made of its analgesic efficacy, side effects and level of satisfaction.

MATERIAL AND METHODS

A study was made of 17 burn patients operated on in our unit who received continuous intravenous analgesia during the postoperative period, with morphine at 1mg/h, using elastomeric infusors for a period of 24h. Its analgesic efficacy was analysed using the visual analogical scale (VAS) at different moments; side effects and the level of acceptance by the patient was also evaluated.

RESULTS

The results confirm a good analgesic effect after 2h from starting perfusion (VAS < 3). The side effects reveal a similar or lesser incidence to the use of morphine in bolus or using the PCA system, and in no cases did they require treatment to be halted. The level of acceptance of the procedure by patients was good.

CONCLUSION

This method reveals a high level of analgesic efficacy in the postoperative period with burn patients in this study. However, it is important to note the lower results obtained in the first hours of perfusion, and proposing a heavy initial dose of analgesics when starting perfusion. This is presented as an efficient analgesic method that is easy to apply, has a low cost, and the possibility of extending its indications to ambulatory treatment.

Anaesthetics

Anaesthesia, like all other medical specialities continues to advance, with improvements in the agents used and techniques employed in order to minimise adverse effects to the patient. This review examines some of these advances and looks forward to what the future might hold in other areas. As well as purely technical advances, other facets of anaesthetic service provision are reviewed, paying particular attention to how to provide a high quality service within the constraints of current working time legislation and revalidation.

Ambulatory surgery adult patient selection criteria — a survey of Canadian anesthesiologists

PURPOSE

An increasing number of patients with complex medical problems are now considered suitable for ambulatory surgery. The purpose of this study was to identify the current clinical practice of ambulatory surgical patient selection.

METHODS

A standardized questionnaire specifying 30 clinical conditions was sent to all practicing anesthesiologists who are members of the Canadian Anesthesiologists' Society. Recipients were asked to indicate if they would provide ambulatory anesthesia (yes/no answers) for an adult patient with each of those isolated conditions. A 75% agreement was considered a majority opinion.

RESULTS

One thousand three hundred thirty-seven questionnaires were sent and 774 replies were received (57.8%). Over 75% of anesthesiologists were willing to include in their selection criteria American Society of Anesthesiologists' (ASA) physical status III, patients with low-grade angina pectoris (AP) and congestive heart failure (CHF), prior myocardial infarction, asymptomatic valvular disease, sleep apnea without use of narcotics, morbid obesity (MO) without co-morbidities, insulin dependent diabetes mellitus and malignant hyperthermia (MH) susceptible patients. Over 75% of responders found ASA IV patients, high grade AP and CHF, sleep apnea with postoperative narcotics, MO with co-morbidities and no patient escort to be unsuitable for ambulatory anesthesia.

CONCLUSION

Our survey demonstrated that medical conditions with extreme grades of severity (mild or severe) are associated with majority opinion to proceed or not to proceed with ambulatory surgery. Issues with over 75% agreement reflect the common practice. Similar surveys may form a part of patient selection guidelines development in the future.

General anaesthesia or spinal anaesthesia for outpatient urological surgery

BACKGROUND AND OBJECTIVE

A variety of drugs and techniques have been introduced into ambulatory anaesthesia. The technique as well as the drugs used may hasten or delay home discharge. We compared recovery profiles and side-effects of spinal anaesthesia and total intravenous anaesthesia.

METHODS

Forty unpremedicated ASA I-II patients (18-65 yr) undergoing varicocele repair were randomly divided into two groups. Spinal anaesthesia (26-G atraumatic needle) with hyperbaric bupivacaine 0.5% 5 mg and fentanyl 25 microg were given to patients in Group Spinal (n = 20). Patients in Group TIVA (n = 20) received total intravenous anaesthesia with propofol and remifentanil given by continuous infusion; a laryngeal mask was used to secure the airway. The duration of surgery, time to home readiness and side-effects were recorded.

RESULTS

The two groups were comparable with respect to patients' characteristics and duration of surgery. The times to achieve ambulation were similar between groups (Spinal = 78.4 +/- 40.9 min, TIVA = 75.9 +/- 13.8 min). Urinary voiding was a requirement for discharge after spinal anaesthesia and the time for home readiness was longer in Group Spinal (158.0 +/- 40.2 versus 94.9 +/- 18.8 min) (P < 0.05). Two patients reported pruritus and one reported postdural puncture headache in Group Spinal, whereas two patients reported nausea in Group TIVA. Patients in Group TIVA had a greater need for analgesia postoperation (P < 0.05).

CONCLUSIONS

In healthy unpremedicated men undergoing minor urological operations, total intravenous anaesthesia with remifentanil and propofol provided as safe and effective anaesthesia as spinal block with the advantage of earlier home readiness.

Advances in office-based anesthesia

PURPOSE OF REVIEW

The practice of office-based anesthesia is quickly emerging as an important field for the anesthesia provider. The number of procedures being done in offices around the country has steadily increased, as has the invasiveness of these procedures. This creates new anesthetic considerations. To date most training programs have not addressed this area of practice. As practitioners enter the field, however, they should have information as to how to provide quality care in a location where very often they are completely alone. Many of the safety mechanisms we as anesthesia providers take for granted in a hospital setting are often not present in a surgical office, and it becomes our responsibility to help in establishing standards.

RECENT FINDINGS

Some questions exist as to the 'safety' of many surgical offices in which anesthesia care is provided. Many medical professional societies have begun issuing recommendations as to the standards of care that should exist. Different anesthetic techniques are also emerging that are appropriate to the office setting.

SUMMARY

As office-based anesthesia continues to mature as a specialty, we the anesthesia providers must be proactive in establishing guidelines and recommendations to make the practice safe. We should be informed of the rules and regulations that exist in our states, and we should provide a voice for the patients who put their faith in us.

Cricoid yoke: the effect of surface area and applied force on discomfort experienced by conscious volunteers

BACKGROUND AND OBJECTIVE

The application of cricoid force is central to techniques that reduce the risk of gastric regurgitation and the subsequent pulmonary aspiration associated with obstetric and emergency anaesthesia. The discomfort associated with cricoid force in awake preoperative patients increases the incidence of coughing, struggling and pain during induction of anaesthesia. This study determined if increasing the surface area of a cricoid yoke reduced the associated discomfort in volunteers.

METHODS

Fifty volunteers participated in a randomized single-blinded study. The cricoid yoke was positioned using standard anatomical landmarks and forces of 10, 20, 30 and 40 N were applied in a random order for 20s, using two different yoke attachments with surface areas of 3 and 10 cm2. A rest of 30s was allowed between the application of forces. Discomfort was graded by volunteers on a scale from 0 to 10 (0: no discomfort; 10: worse discomfort imaginable). A score of 10 was allocated if the volunteers could not tolerate the applied force for 20s.

RESULTS

Median scores for the small yoke were always higher than those for the large yoke at each force. There were significant differences between the scores for the small and large yokes at 10 and 20 N (P < 0.001) and 30 N (P = 0.0233), but there was no significant difference at 40 N.

CONCLUSIONS

The larger yoke was tolerated better by volunteers when clinically relevant cricoid forces were applied.

Tracheal intubation without muscle relaxants: remifentanil or alfentanil in combination with propofol

BACKGROUND AND OBJECTIVE

In some situations, the use of muscle relaxants (neuromuscular blocking drugs) are undesirable or contraindicated. We compared intubating conditions without muscle relaxants in premedicated patients receiving either alfentanil 40 microg kg(-1) or remifentanil 2, 3 or 4 microg kg(-1) followed by propofol 2 mg kg(-1).

METHODS

In a randomized, double-blind study, 80 healthy patients were assigned to one of four groups (n = 20). After intravenous atropine, alfentanil 40 microg kg(-1) or remifentanil 2, 3 or 4 microg kg(-1) were injected over 90 s followed by propofol 2 mg kg(-1). Ninety seconds after administration of the propofol, laryngoscopy and tracheal intubation were attempted. Intubating conditions were assessed as excellent, good or poor on the basis of ease of lung ventilation, jaw relaxation, laryngoscopy, position of the vocal cords, and patient response to intubation and slow inflation of the endotracheal tube cuff.

RESULTS

Seven patients who received remifentanil 2 microg kg(-1) and one patient who received remifentanil 3 microg kg(-1) could not be intubated at the first attempts. Excellent intubating conditions (jaw relaxed, vocal cords open and no movement in response to tracheal intubation and cuff inflation) were observed in those who received either alfentanil 40 microg kg(-1) (45% of patients) or remifentanil in doses of 2 microg kg(-1) (20%), 3 microg kg(-1) (75%) or 4 microg kg(-1) (95%). Overall, intubating conditions were significantly better (P < 0.05), and the number of patients showing excellent conditions were significantly higher (P < 0.05) in patients who received remifentanil 4 microg kg(-1) compared with those who received alfentanil 40 microg kg(-1) or remifentanil 2 microg kg(-1). No patient needed treatment for hypotension or bradycardia.

CONCLUSIONS

Remifentanil 4 microg kg(-1) and propofol 2 mg kg(-1) administered in sequence intravenously provided good or excellent conditions for tracheal intubation in all patients without the use of muscle relaxants.

Stability of the LMA-ProSeal and standard laryngeal mask airway in different head and neck positions: a randomized crossover study

BACKGROUND AND OBJECTIVE

The LMA-ProSeal laryngeal mask airway is a new laryngeal mask airway with a modified cuff and drainage tube. We compared oropharyngeal leak pressure, intracuff pressure and anatomical position (assessed fibreoptically) for the Size 5 LMA-ProSeal laryngeal mask airway and the classic laryngeal mask airway in different head-neck positions and using different intracuff inflation volumes.

METHODS

Thirty paralysed anaesthetized adult male patients were studied. The LMA-ProSeal laryngeal mask airway and the classic laryngeal mask airway were inserted into each patient in random order. The oropharyngeal leak pressure, intracuff pressure, and anatomical position of the airway tube and drainage tube (LMA-ProSeal laryngeal mask airway only) were documented in four head and neck positions (neutral first, then flexion, extension and rotation in random order), and at 0-40 mL cuff volumes in the neutral position in 10 mL increments.

RESULTS

Compared with the neutral position, the oropharyngeal leak pressure for both the LMA-ProSeal laryngeal mask airway and the classic laryngeal mask airway was higher in flexion and rotation (all P < or = 0.02), but lower in extension (all P < or = 0.01). Changes in head-neck position did not alter the anatomical position of the airway tube or the drainage tube. The oropharyngeal leak pressure was always higher for the LMA-ProSeal laryngeal mask airway (all P < or = 0.005) and anatomical position better for the classic laryngeal mask airway (all P < or = 0.04).

CONCLUSIONS

The anatomical position of the LMA-ProSeal and the classic laryngeal mask airway is stable in different head-neck positions, but head-neck flexion and rotation are associated with an increase, and head-neck extension a decrease, in oropharyngeal leak pressure and intracuff pressure. The Size 5 LMA-ProSeal laryngeal mask airway is capable of forming a more effective seal than the Size 5 classic laryngeal mask airway in males.

Breathing pattern and workload during automatic tube compensation, pressure support and T-piece trials in weaning patients

BACKGROUND AND OBJECTIVE

Automatic tube compensation has been designed as a new ventilatory mode to compensate for the non-linear resistance of the endotracheal tube. The study investigated the effects of automatic tube compensation compared with breathing through a T-piece or pressure support during a trial of spontaneous breathing used for weaning patients from mechanical ventilation of the lungs.

METHODS

Twelve patients were studied who were ready for weaning after prolonged mechanical ventilation (10.2 +/- 8.4 days) due to acute respiratory failure. Patients with chronic obstructive pulmonary disease were excluded. Thirty minutes of automatic tube compensation were compared with 30 min periods of 7 cmH2O pressure support and T-piece breathing. Breathing patterns and workload indices were measured at the end of each study period.

RESULTS

During T-piece breathing, the peak inspiratory flow rate (0.65 +/- 0.20 L s(-1)) and minute ventilation (8.9 +/- 2.7L min(-1)) were lower than during either pressure support (peak inspiratory flow rate 0.81 +/- 0.25 L s(-1) minute ventilation 10.2 +/- 2.3 L min(-1), respectively) or automatic tube compensation (peak inspiratory flow rate 0.75 +/- 0.26L s(-1); minute ventilation 10.8 +/- 2.7 L min(-1)). The pressure-time product as well as patients' work of breathing were comparable during automatic tube compensation (pressure-time product 214.5 +/- 104.6 cmH2O s(-1) min(-1), patient work of breathing 1.1 +/- 0.4 J L(-1)) and T-piece breathing (pressure-time product 208.3 +/- 121.6 cmH2O s(-1) min(-1), patient work of breathing 1.1 +/- 0.4 J L(-1)), whereas pressure support resulted in a significant decrease in workload indices (pressure-time product 121.2 +/- 64.1 cmH2O s(-1) min(-1), patient work of breathing 0.7 +/- 0.4 J L(-1)).

CONCLUSIONS

In weaning from mechanical lung ventilation, patients' work of breathing during spontaneous breathing trials is clearly reduced by the application of pressure support 7 cmH2O, whereas the workload during automatic tube compensation corresponded closely to the values during trials of breathing through a T-piece.

Anaesthetic agents in adult day case surgery

This study reports a review of all comparative published studies of adult day case anaesthesia in the English language up to December 2000. Ten databases were searched using appropriate keywords and data were extracted in a standardized fashion. One hundred-and-one published studies were examined. Recovery measurements were grouped as early, intermediate, late, psychomotor and adverse effects. With respect to induction of anaesthesia, propofol was superior to methohexital, etomidate and thiopental, but equal to sevoflurane and desflurane. Desflurane and sevoflurane were both superior to thiopental. There was no detectable difference between sevoflurane and isoflurane. With respect to the maintenance of anaesthesia, isoflurane and halothane were the worst. There were no significant differences between propofol, desflurane, sevoflurane and enflurane. Propofol is the induction agent of choice in day case patients. The use of a propofol infusion and avoidance of nitrous oxide may help to reduce postoperative nausea and vomiting.

Prediction of difficult tracheal intubation

BACKGROUND AND OBJECTIVE

Preoperative bedside screening tests for difficult tracheal intubation may be neither sensitive nor specific enough for clinical use. The aim was to investigate if a combination of the Mallampati classification of the oropharyngeal view with either the thyromental or sternomental distance measurement improved the predictive value.

METHODS

A total of 212 (109 male, 103 female) non-obstetric surgical patients, aged >18 yr, undergoing elective surgical procedures requiring tracheal intubation were assessed preoperatively with respect to the oropharyngeal (modified Mallampati) classification, thyromental and sternomental distances. An experienced anaesthetist, blinded to the preoperative airway assessment, performed laryngoscopy and graded the view according to Cormack and Lehane's classification.

RESULTS

Twenty tracheal intubations (9%) were difficult as defined by a Cormack and Lehane Grade 3 or 4, or the requirement for a bougie in patients with Cormack and Lehane Grade 2. Used alone, the Mallampati oropharyngeal view, and thyromental and sternomental distances were associated with poor sensitivity, specificity and positive predictive values. Combining the Mallampati Class III or IV with either a thyromental distance <6.5cm or a sternomental distance <12.5cm decreased the sensitivity (from 40 to 25 and 20%, respectively), but maintained a negative predictive value of 93%. The specificity and positive predictive values increased from 89 and 27% respectively for Mallampati alone to 100%.

CONCLUSIONS

The findings suggest that the Mallampati classification, in conjunction with measurement of the thyromental and sternomental distances, may be a useful routine screening test for preoperative prediction of difficult tracheal intubation.