The changing role of monitored anesthesia care in the ambulatory setting

Evaluation of Monitored Anesthesia Care in Sialendoscopy

Importance

In the United States, sialendoscopy is most often performed under general anesthesia with endotracheal intubation (GETA); however, monitored anesthesia care (MAC) may be a viable alternative.

Objective

To investigate patient characteristics and outcomes following sialendoscopy performed under MAC or GETA to assess the potential of MAC as an alternative anesthetic option.

Design, Setting, and Participants

A retrospective review of medical records on patients who underwent sialendoscopy between October 1, 2011, and August 31, 2014, was performed. Patient characteristics, salivary stone characteristics, intraoperative findings, operative time (OT), anesthesia time (AT), and outcomes were evaluated. Data analysis was performed from November 1, 2015, to March 1, 2016.

Main Outcomes and Measures

Operative and anesthetic times for sialendoscopy under MAC and GETA.

Results

Sixty-five patients underwent 70 sialendoscopy procedures: 27 performed under MAC, 43 under GETA. Overall, 37 of 65 (56.9%) patients were women, with 17 (63.0%) in the MAC group and 20 (52.6%) in the GETA group. Mean (SD) patient age was 49.4 (17.3) and 47.2 (16.2) years for the MAC and GETA cohorts, respectively. Median (25th-75th quartiles) OT in minutes for MAC cases was significant for no stones (49.0 [31.0-49.0]) and stones (41.0 [28.0-92.0]) present; nonsignificant findings were stones in the Wharton (46.0 [28.0-92.0]) and Stenson (37.0; 1 case) ducts. For GETA cases, significance was also demonstrated for no stones (55.0 [52.0-91.0]) and stones (77.0 [56.0-107.0]) present; nonsignificant findings were stones in the Wharton (79.0 [56.0-107.0]) and Stenson (65.0 [49.0-98.0]) ducts. The AT in minutes for MAC cases was significant for no stones (33.0 [30.0-39.0]) and stones (38.0 [32.0-55.0]) present; nonsignificant findings were stones in the Wharton (60.0 [32.0-55.0]) and Stenson (37.0; 1 case) ducts. For GETA cases, findings were also significant for no stones (61.0 [52.0-67.0]) and stones (59.0 [53.0-67.0]) present; nonsignificant findings were stones in the Wharton (60.0 [54.0-69.0]) and Stenson (52.0 [48.0-61.0]) ducts.

Conclusions and Relevance

This study suggests that sialendoscopy under MAC has faster median OT and AT, regardless of varying case circumstances, such as the presence or lack of stones, successful stone removal, stone size (>5 mm), stone location, and sialendoscopy-assisted open procedures. Sialendoscopy under MAC may be a reasonable anesthetic alternative to GETA in an appropriate setting with an experienced surgeon, experienced anesthesiologist comfortable with administering MAC, cases with small (<4-mm) singular stones, and patients comfortable with undergoing the procedure without GETA.

Effect of environmental noise and music on dexmedetomidine-induced sedation in dogs

Background

Previous studies in human patients suggest depth of sedation may be affected by environmental noise or music; however, related data in domestic animals is limited. The objective of the current study was to investigate the effect of noise and music on dexmedetomidine-induced (DM- 10 µg/kg, IM) sedation in 10 dogs.

Methods

In a crossover design, post-DM injection dogs were immediately subjected to recorded human voices at either 55–60 decibel (dB) (Noise 1) or 80–85 dB (Noise 2); classical music at 45–50 dB (Music); or background noise of 40–45 dB (Control+). Control− included IM saline injection and exposure to 40–45 dB background noise. Sedation was assessed via monitoring spontaneous behavior and accelerometry (delta-g) throughout three 20-min evaluation periods: baseline, noise exposure, and post-treatment. Sedation was further assessed during two restraint tests at 30 min (R1) and 40 min (R2) post-injection. A mixed model for crossover design was used to determine the effect of noise exposure and time on either spontaneous behavior scores or delta-g. The restraint scores were analyzed using a two-way repeated measures ANOVA.

Results

Spontaneous behavior scores indicated less sedation during Noise 2 compared to Control+ (P = 0.05). R2 restraint scores for all DM treatments except Noise 2 indicated significantly higher sedation than Control− [C+ (P = 0.003), M (P = 0.014) and N1 (P = 0.044)].

Discussion

Results suggest that the quality of sedation is negatively impacted by high-intensity noise conditions (80–85 dB), but exposure to music did not improve sedation in this population of research dogs.

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.

Monitored anesthesia care in and outside the operating room

Monitored anesthesia care (MAC) is an anesthesia technique combining local anesthesia with parenteral drugs for sedation and analgesia. The use of MAC is increasing for a variety of diagnostic and therapeutic procedures in and outside of the operating room due to the rapid postoperative recovery with the use of relatively small amounts of sedatives and analgesics compared to general anesthesia. The purposes of MAC are providing patients with safe sedation, comfort, pain control and satisfaction. Preoperative evaluation for patients with MAC is similar to those of general or regional anesthesia in that patients should be comprehensively assessed. Additionally, patient cooperation with comprehension of the procedure is an essential component during MAC. In addition to local anesthesia by operators or anesthesiologists, systemic sedatives and analgesics are administered to provide patients with comfort during procedures performed with MAC. The discretion and judgment of an experienced anesthesiologist are required for the safety and efficacy profiles because the airway of the patients is not secured. The infusion of sedatives and analgesics should be individualized during MAC. Many procedures in and outside of the operating room, including eye surgery, otolaryngologic surgery, cardiovascular procedures, pain procedures, and endoscopy are performed with MAC to increase patient and operator satisfaction.

Monitored anesthesia care for great saphenous vein stripping surgery with target controlled infusion of propofol and remifentanil: a prospective study

Background

The aim of this study was to determine the appropriate target concentrations at the effect site of propofol and remifentanil when deep sedation was achieved by monitored anesthesia care (MAC) anesthesia and related respiratory depression during vein stripping surgery for varicose veins.

Methods

In total, 51 adult patients who were scheduled for varicose vein stripping surgery were sedated with propofol and remifentanil during the surgery, after administration of midazolam. Target concentrations at the effect site of the two drugs were changed based on the patient's status. Respiratory support was applied in the order of oxygen supply, chin lift, and assisted mask ventilation. Target concentrations at the effect site of propofol and remifentanil, the need for respiratory support, and a six-point rating scale satisfaction score were the outcome measurements.

Results

Only one patient did not require oxygen, eight patients needed oxygen alone, 22 patients required use of the chin lift technique, and 20 patients were assisted with mask ventilation. There was no significant difference in the target concentration of propofol or remifentanil between the patients who required mask ventilation and those who did not. Fifty of the 51 patients reported a satisfaction score of 6.

Conclusions

Although MAC using low target concentrations of propofol and remifentanil during vein stripping surgery was satisfactory to patients, close observation regarding the need for respiratory assistance was necessary.

Efficacy and cost analysis of transrectal ultrasound-guided prostate biopsy under monitored anesthesia

Sedation may result in reduction in pain during transrectal ultrasound (TRUS)-guided prostate biopsies. We aimed to evaluate the efficacy and safety of a combination of propofol and remifentanil infusion during TRUS-guided prostate biopsy and the related increases in health care costs. From January to September 2010, 100 men undergoing a transrectal prostate biopsy were randomized into two groups. In Group 1, 50 patients received a combined infusion of propofol and remifentanil; in Group 2, 50 patients received lidocaine jelly. After TRUS-guided biopsies were performed, pain and patient satisfaction were evaluated by a 10-point visual analog scale (VAS), and a cost-related patient satisfaction questionnaire was completed by all patients. Patients were also asked whether they would be willing to undergo repeat biopsy by the same method. Patients in Group 1 showed a significantly lower VAS score than those in Group 2 (mean VAS score: 0.9±1.1 versus 6.3±2.5; P<0.001). In addition, the patient satisfaction scale was significantly higher in Group 1 (P=0.002). Although the overall cost was significantly higher in Group 1 (P=0.006), patient satisfaction scales considering cost were also higher in this group (P=0.009). A combination of propofol and remifentanil is a safe and effective way to decrease patient pain and increase patient satisfaction during TRUS-guided prostate biopsy. Although the costs were higher in the group that received sedation, as expected, the patients exhibited heightened satisfaction and willingness to repeat biopsies by the same method.

Enhancement of GABAergic activity: neuropharmacological effects of benzodiazepines and therapeutic use in anesthesiology

GABA is the major inhibitory neurotransmitter in the central nervous system (CNS). The type A GABA receptor (GABA(A)R) system is the primary pharmacological target for many drugs used in clinical anesthesia. The α1, β2, and γ2 subunit-containing GABA(A)Rs located in the various parts of CNS are thought to be involved in versatile effects caused by inhaled anesthetics and classic benzodiazepines (BZD), both of which are widely used in clinical anesthesiology. During the past decade, the emergence of tonic inhibitory conductance in extrasynaptic GABA(A)Rs has coincided with evidence showing that these receptors are highly sensitive to the sedatives and hypnotics used in anesthesia. Anesthetic enhancement of tonic GABAergic inhibition seems to be preferentially increased in regions shown to be important in controlling memory, awareness, and sleep. This review focuses on the physiology of the GABA(A)Rs and the pharmacological properties of clinically used BZDs. Although classic BZDs are widely used in anesthesiological practice, there is a constant need for new drugs with more favorable pharmacokinetic and pharmacodynamic effects and fewer side effects. New hypnotics are currently developed, and promising results for one of these, the GABA(A)R agonist remimazolam, have recently been published.

Fast track colorectal surgery

A "fast track" colon surgery program is the global package of perioperative care encompassing preoperative, operative, and postoperative techniques, which in aggregate result in fewer complications, a reduction in cost, less postoperative pain, a reduction in the hospital length of stay, and quicker return to work and normal activities. Results of fast track programs have shown significant advantages; however, strong evidence is forthcoming. Implementation of a fast track program requires a significant commitment and a multidisciplinary approach. Fast track principles may also be applied to anorectal surgery with good results.

Office-based anaesthesia

Office-based anaesthesia is a young but rapidly growing speciality practice. In patient selection, surgical procedures, and anaesthetic techniques this practice is similar to standard ambulatory surgery; however, the liability and risks of office-based anaesthesia are greater. The anaesthesiologist's major challenge is to insist on patient safety in this developing field.

Continuous professional development for anaesthetists

Anaesthesia, as well as the whole of medicine, is involved in a revolution not only technical but also economic, because of the need for cost-containment in healthcare delivery. Continuing medical education, primarily devoted to updating knowledge and skills, is moving rapidly towards continuous professional development. A permanent evolution of practitioners is mandatory in order that they are able to adapt their practice to technical, ethical and economic changes, integrated in a team-working and multidisciplinary approach to patient care.

Arterial to end-tidal carbon dioxide tension difference in anaesthetized adults mechanically ventilated via a laryngeal mask or a cuffed oropharyngeal airway

To evaluate arterial (PaCO2), end-tidal (PETCO2) and carbon dioxide tension difference during mechanical ventilation with extratracheal airways, 60 patients ASA physical status I-II, receiving general anaesthesia for minor extra-abdominal procedures were randomly allocated to receive either a cuffed oropharyngeal airway (group COPA, n = 30) or a laryngeal mask (group LMA, n = 30). The lungs were mechanically ventilated by IPPV using a 60% nitrous oxide and 1-1.5% isoflurane in oxygen mixture (VT = 8 mL kg-1; RR = 12 b min-1; l/E = 1/2). After PETCO2 had been stable for at least 10 min after airway placement, haemodynamic variables and PETCO2 were recorded and an arterial blood sample was obtained for measurement of PaCO2. No differences in anthropometric parameters, smoking habit, haemodynamic variables and incidence of untoward events were observed between the two groups. Airway manipulation, to maintain adequate ventilation, was required in only nine patients in the cuffed oropharyngeal airway group (30%) (P < 0.0005); however, in no case was it necessary to remove the designated extratracheal airway due to unsuccessful mechanical ventilation. The mean difference between arterial and end-tidal carbon dioxide partial pressure was 0.4 +/- 0.3 KPa in the laryngeal mask group (95% confidence intervals: 0.3-0.5 KPa) and 0.3 +/- 0.26 KPa in the cuffed oropharyngeal airway group (95% confidence intervals: 0.24-0.4 KPa) (P = NS). We conclude that in healthy adults who are mechanically ventilated via the cuffed oropharyngeal airway, the end-tidal carbon dioxide determination is as accurate an indicator of PaCO2 as that measured via the laryngeal mask, allowing capnometry to be reliably used to evaluate the adequacy of ventilation.

What is new in monitored anesthesia care?

The use of monitored anesthesia care (MAC) techniques is increasing in popularity because recovery profiles seem to be improved compared with general and regional anesthesia. This article describes the conceptual basis for MAC and reviews the current MAC practices.

Fast-track concept for ambulatory anesthesia

Fast-tracking in the ambulatory setting refers to the ability to transfer suitably recovered patients from the operating room directly to the Phase II (step-down) recovery area, bypassing the postanesthesia care unit. This article describes the concept of fast-tracking after ambulatory surgery and reviews anesthetic techniques that have helped to facilitate this process. The prevention and management of postoperative pain and nausea are also discussed.