The rise, fall, and future direction of computer-assisted personalized sedation.

PURPOSE OF REVIEW: The first computer-assisted personalized sedation (CAPS) device was developed to address the growing demand for routine endoscopy procedures in the United States in the early 2000s. This review will describe the environment that gave rise to CAPS and summarize the design of that first device. It will then discuss the market forces that led to the fall of CAPS, with sales of the device ending 2 years after commercialization. RECENT FINDINGS: CAPS was initially conceived as a means to enable proceduralists to administer conscious sedation with propofol safely. In the nearly 20 years since its conception, the expectations of patients and proceduralists for endoscopy sedation, have evolved from conscious sedation to deep. Due to the increased risk inherent in deep sedation, future CAPS devices should be tools for anesthesiologists, not proceduralists. SUMMARY: Over $2 billion are spent annually for anesthesia services in routine endoscopic procedures for low-risk patients; a spending rate that is not sustainable. CAPS, in an 'anesthesia oversight' model similar to medical supervision, has a future as a cost-efficient means for anesthesia services to provide sedation in endoscopy and other nonoperating room venues. Anesthesiologists should work with medical device companies and payers to develop a CAPS 'anesthesia oversight' model.

Halving the volume of AnaConDa: initial clinical experience with a new small-volume anaesthetic reflector in critically ill patients-a quality improvement project.

AnaConDa-100 ml (ACD-100, Sedana Medical, Uppsala, Sweden) is well established for inhalation sedation in the intensive care unit. But because of its large dead space, the system can retain carbon dioxide (CO2) and increase ventilatory demands. We therefore evaluated whether AnaConDa-50 ml (ACD-50), a device with half the internal volume, reduces CO2 retention and ventilatory demands during sedation of invasively ventilated, critically ill patients. Ten patients participated in this cross-over protocol. After sedation with isoflurane via ACD-100 for 24 h, the 5-h observation period started. During the first hour, ACD-100 was used; for the next 2 h, ACD-50; and for the last 2 h, ACD-100 was used again. Sedation was titrated to Richmond Agitation and Sedation Scale (RASS) score - 3 to - 4 and a processed electroencephalogram (Narcotrend Index, Narcotrend-Gruppe, Hannover, Germany) was recorded. Minute ventilation, CO2 elimination, and isoflurane consumption were compared. All patients were deeply sedated (Narcotrend Index, mean ± SD: 38 ± 10; RASS scores - 3 to - 5) and breathed spontaneously with pressure support throughout the observation period. Infusion rates of isoflurane and opioid, either remifentanil or sufentanil, as well as ventilator settings were unchanged. Minute ventilation and end-tidal CO2 were significantly reduced with the ACD-50, respiratory rate remained unchanged, and tidal volume decreased by 66 ± 43 ml. End-tidal isoflurane concentrations were also slightly reduced while haemodynamic measures remained constant. The ACD-50 reduces the tidal volume needed to eliminate carbon dioxide without augmenting isoflurane consumption.

[New technical developments for inhaled sedation]. / Neue technische Entwicklungen der inhalativen Sedierung.

The circle system has been in use for more than 100 years, whereas the first clinical application of an anaesthetic reflector was reported just 15 years ago. In the circle system, all breathing gas is rebreathed after carbon dioxide absorption. A reflector, on the other hand, with the breathing gas flowing to and fro, specifically retains the anaesthetic during expiration and resupplies it during the next inspiration. A high reflection efficiency (number of molecules resupplied/number of molecules exhaled, RE 80-90%) decreases consumption. In analogy to the fresh gas flow of a circle system, pulmonary clearance ((1-RE) × minute ventilation) defines the opposition between consumption and control of the concentration.It was not until reflection systems became available that volatile anaesthetics were used routinely in some intensive care units. Their advantages, such as easy handling, and better ventilatory capabilities of intensive care versus anaesthesia ventilators, were basic preconditions for this. Apart from AnaConDa™ (Sedana Medical, Uppsala, Sweden), the new MIRUS™ system (Pall Medical, Dreieich, Germany) represents a second, more sophisticated commercially available system.Organ protective effects, excellent control of sedation, and dose-dependent deep sedation while preserving spontaneous breathing with hardly any accumulation or induction of tolerance, make volatile anaesthetics an interesting alternative, especially for patients needing deep sedation or when intravenous drugs are no longer efficacious.But obviously, the outcome is most important. We know that deep intravenous sedation increases mortality, whereas inhalational sedation could prove beneficial. We now need prospective clinical trials examining mortality, but also the psychological outcome of those most critically ill patients sedated by inhalation or intravenously.

Propofol sedation with a target-controlled infusion pump and bispectral index monitoring system in elderly patients during a complex upper endoscopy procedure.

BACKGROUND AND AIMS: Although the usefulness of propofol sedation during endoscopic submucosal dissection (ESD) for gastric neoplasms was reported previously, information is limited on its use in elderly patients. We investigated the safety and efficacy of propofol sedation with a target-controlled infusion (TCI) pump and bispectral index (BIS) monitoring system (TCI/BIS system) in elderly patients during gastric ESD. METHODS: Included were 413 consecutive gastric ESD procedures involving 455 lesions (379 patients) performed in patients under propofol sedation with a TCI/BIS system between October 2009 and September 2013. Patients were divided into 3 groups: group A, age <70 years (n = 162); group B, age ≥70 and <80 years (n = 171); and group C, age ≥80 years (n = 80). We compared the propofol dose and adverse events (eg, hypotension and hypoxemia) during ESD. RESULTS: Older groups required a lower target concentration of propofol (group A: median 2.1 µg/mL [interquartile range (IQR), 1.9-2.3]; group B: median 1.6 µg/mL [IQR, 1.3-1.8]; and group C: median 1.4 µg/mL [IQR, 1.2-1.6]; P < .0001). Hypotension tended to occur in the younger group, and hypoxemia occurred at a significantly higher rate in the older groups, although the number of cases was small. Low preoperative systolic blood pressure (≤125 mm Hg) was associated with hypotension (odds ratio [OR], 1.73; 95% confidence interval [CI], 1.12-2.70; P = .013) and abnormal pulmonary function was associated with hypoxemia in groups B and C (OR, 4.54; 95% CI, 1.01-31.5; P = .048). CONCLUSIONS: Elderly patients required lower doses of propofol with the TCI/BIS system than younger patients. Attention to hypoxemia is necessary in elderly patients, particularly patients with abnormal pulmonary function.

Education and training for nonanesthesia providers performing deep sedation.

PURPOSE OF REVIEW: There has been a significant increase in the number and types of procedures performed outside of the operating room with nonanesthesia providers administering sedation. This review describes current recommendations for training nonanesthesiologists involved in administering deep sedation, summarizes best practices and highlights select patient outcomes. RECENT FINDINGS: There are numerous guidelines and standards related to the administration of deep sedation. However, there are no universally accepted guidelines regarding the necessary educational and skill competencies needed for nonanesthesiologists to provide deep sedation. The American Society of Anesthesiologists has published a position statement and guidelines on these educational requirements, yet the extent to which these are adhered to remains unknown. As evidence-based guidelines continue to evolve, more research is needed to describe how current practices affect patient outcomes. SUMMARY: The American Society of Anesthesiologists publishes recommendations regarding the essential educational components for nonanesthesiologist providers who administer deep sedation. The available data support the need for formal educational programmes to prevent adverse events associated with deep sedation. Competencies should include preprocedural evaluation, understanding sedation levels, airway management, documentation, emergency life support skills, teamwork and quality improvement.

Practical considerations in the management of sedation for colonoscopy.

PURPOSE OF REVIEW: The purpose of this review is to discuss the unique elements of providing anesthesia services for colonoscopy including the practical issues within an endoscopy suite, nothing by mouth status for colonoscopy, chronic medication instructions, appropriate anesthesia equipment, informed consent, pharmacology of agents for sedation, anesthetic techniques, and issues related to postprocedural care. RECENT FINDINGS: The national trend is toward increasing number and complexity of colonoscopy procedures using anesthesia services. Providing anesthesia services in a dedicated endoscopy suite has unique elements related to open scheduling and the rapid turnover environment. Agents for sedation and general anesthesia for colonoscopy are chosen for rapid onset, amnestic properties, and raid emergence/recovery. SUMMARY: Sedation for colonoscopy is a rapidly expanding subspecialty with special needs created by the increasing medical complexity of the patients, the demands of the endoscopy procedures, the challenges of the endoscopy suite, and the rapid turnover of the outpatient environment.

Use of computer-assisted drug therapy outside the operating room.

PURPOSE OF REVIEW: The number of procedures performed in the out-of-operating room setting under sedation has increased many fold in recent years. Sedation techniques aim to achieve rapid patient turnover through the use of short-acting drugs with minimal residual side-effects (mainly propofol and opioids). Even for common procedures, the practice of sedation delivery varies widely among providers. Computer-based sedation models have the potential to assist sedation providers and offer a more consistent and safer sedation experience for patients. RECENT FINDINGS: Target-controlled infusions using propofol and other short-acting opioids for sedation have shown promising results in terms of increasing patient safety and allowing for more rapid wake-up times. Target-controlled infusion systems with real-time patient monitoring can titrate drug doses automatically to maintain optimal depth of sedation. The best recent example of this is the propofol-based Sedasys sedation system. Sedasys redefined individualized sedation by the addition of an automated clinical parameter that monitors depth of sedation. However, because of poor adoption and cost issues, it has been recently withdrawn by the manufacturer. SUMMARY: Present automated drug delivery systems can assist in the provision of sedation for out-of-operating room procedures but cannot substitute for anesthesia providers. Use of the available technology has the potential to improve patient outcomes, decrease provider workload, and have a long-term economic impact on anesthesia care delivery outside of the operating room.

[THE USE OF VOLATILE AGENTS FOR SEDATION IN CHILDREN IN THE INTENSIVE CARE UNIT].

Sedation is a controllable level of medication depression of consciousness during which protective reflexes, adequate breathing, and responsiveness to physical stimuli and verbal commands are retained A number of physical and psychological factors affect the psyche of patients in the intensive care unit. Central nervous system (CNS) is a primary target of action of anesthetics and analgesics, and the bi-spectral index reflects the level of sedation of CNS, regardless of what drug caused sedation. The aim of this study was to use volatile anesthetics sevoflurane and isoflurane in children for sedation in the intensive care unit. Constant use of the inhalation route of administration helps to maintain the desired level of sedation depth for the required period of time in patients who are on long-term sedation and is practical for correction.

SEDASYS(®), airway, oxygenation, and ventilation: anticipating and managing the challenges.

In May 2013, the FDA (Federal Drug Administration) approved SEDASYS(®), a device that enables non-anesthesia physicians to provide mild-to-moderate sedation to patients undergoing colonoscopy and esophagogastroduodenoscopy. SEDASYS(®) is the first among the devices being built to provide computer-assisted personalized sedation. Although the intention of this approval is to cut the anesthesia related expenses, it is likely to create new challenges to the users-both clinical and administrative-that might even increase the cost. Deep sedation is required frequently for a successful completion of the procedure, which poses unforeseen challenges. The present review aims to provide clear information to the users regarding pre-procedure assessment, possible sedation related complications and management options.

Deep sedation with sevoflurane insufflated via a nasal cannula in uncooperative child undergoing the repair of dental injury.

Sevoflurane, a potent volatile anesthetic, has been attempted to be used for procedural sedation. Because of lack of a commercially available sedation apparatus for sevoflurane administration, anesthetic gas delivery apparatus should be connected to general anesthetic machine for delivering sevoflurane gas. In this case, deep sedation was maintained during treatment of dental injuries involving the upper lip and incisor by sevoflurane insufflations via a nasal cannula. Especially, this may be advantageous in treating dental injuries involving upper lip and maxillary anterior teeth because the treatment is not disturbed during sevoflurane insufflations via a nasal cannula.

Feasibility and potential cost/benefit of routine isoflurane sedation using an anesthetic-conserving device: a prospective observational study.

BACKGROUND: Inhaled sedation is efficient and easily controllable; in low concentrations it causes minimal changes in the patient and very little interference with hemodynamics. Awakening after inhaled sedation is quick and predictable. The major reason inhaled sedation has not become widely used in intensive care is that no commercially available administration device has been available. METHODS: In our intensive care unit we conducted a prospective observational study to assess the feasibility, benefits, and costs of routine isoflurane sedation via the AnaConDa anesthetic-administration device. We included 15 adult patients who required > 24 hours of deep sedation. Conventional intravenous sedation (benzodiazepine and opioid) had been administered according to a sedation protocol that included a predetermined target Ramsay-scale sedation score. We then switched to inhaled isoflurane via the AnaConDa, and measured sedation efficacy, cumulative dose, and daily cost of sedation. Adverse events were prospectively defined and monitored. RESULTS: The sedation goal was reached with isoflurane in all 15 patients (P < .01, compared to the conventional sedation protocol). Hemodynamic changes were nonsignificant, and no renal or hepatic dysfunctions were observed. The frequency of meeting the sedation goal was significantly better with isoflurane than with our usual sedation protocol. With isoflurane, awakening from sedation was always

Office-based ambulatory sedation--the use of the airway protector system during oral surgery: a prospective audit of the first 100 patients.

PURPOSE: To evaluate the efficacy of the "Airway Protector System" (APS), a simple homemade device used for airway control during office-based dental sedation. PATIENTS AND METHODS: A prospective audit was performed in 100 severely dental phobic patients submitted to dental treatment in a dentist office under propofol sedation. RESULTS: Sixty-eight females and 32 males were enrolled in this study. The mean age was 45 +/- 7 years (range, 18 to 67 years). A clear airway was obtained in 94 patients. Partial airway obstruction was observed in 4 patients but manual lifting of the jaw was enough to free the partial obstruction and dental treatment was uneventfully conducted. In 2 patients, the APS had to be converted to formal nasotracheal intubation because jaw-lifting maneuvers did not adequately relieve a partial airway obstruction. Sore throat was reported in 56 patients. In 27 cases, the patients rated the complaint as severe. No patient required a chest x-ray after sedation, as there was no clinical evidence of any pulmonary complication including dyspnea, cough, or fever. CONCLUSION: We suggest that the concomitant use of a homemade cuffed nasopharyngeal airway with continuous suction facilitates airway control during deep levels of office-based sedation for dental treatment in severely dental phobic patients.

A portable device for intensive care brain function monitoring with event-related potentials.

Monitoring level of consciousness or depth of sedation is essential in modern intensive care units and emergency rooms. Current methods are based on spontaneous EEG providing only indirect information on the reactivity of the brain. Measurement of auditory event-related potentials (ERPs) has been shown to have additional potential for evaluation of the level of consciousness. Unfortunately, compact and easy-to-use devices are not commercially available. In this study a portable battery-powered device for clinical auditory ERP measurements was designed, constructed and validated. The device consists of a five-channel data logger and a 16-bit stereo audio stimulator. The signals are digitized with a 22-bit sigma-delta analogue-to-digital converter and stored to a PC Card hard disk. Prior to the in vivo application, the device was validated with extensive technical tests. Importantly, the RMS noise amplitude of the EEG channels was found to be less than 1 mivroV and the delivered auditory stimulus intensity corresponded accurately the settings (mean difference 0.2+/-0.5 dB). In addition to technical tests the device was successfully validated in vivo. To summarize, a novel portable instrument for measurement of auditory event-related potentials in intensive care environment is introduced.

Laryngeal mask airway may result in false negative imaging for carotid medialization: A case report.

Chromosome 22q11.2 microdeletions result in multiple congenital abnormalities, including an increased risk of carotid medialization, which is an important consideration for preoperative planning in children with velopharyngeal insufficiency. Preoperative imaging of the neck vasculature is recommended. Here we describe a case in which a child had negative imaging studies despite the presence of a medialized carotid artery on physical examination, likely secondary to the supraglottic airway use during sedated imaging, which displaced the carotid laterally. The type of airway used should be a consideration for children undergoing sedated imaging prior to pharyngeal procedures.

Renal and hepatic integrity in long-term sevoflurane sedation using the anesthetic conserving device: a comparison with intravenous propofol sedation in an animal model.

INTRODUCTION: Critically ill patients are sedated with intravenous agents because the use of inhaled agents is limited by their potential risk of toxicity. Increasing levels of inorganic fluorides after the metabolism of these agents have been considered potentially nephrotoxic. However, hepatic involvement after prolonged administration of sevoflurane has not yet been studied. The present study evaluated the potential renal and hepatic toxicity caused by prolonged administration (72h) of sevoflurane. METHODS: For this experimental, prospective, randomized, controlled trial, 22 Landrace x Large-White female pigs were randomly assigned to two groups: intravenous propofol (P) or inhaled sevoflurane via the AnaConDa™ device (S, end-tidal 2.5 vol%). The P group remained sedated for 108h with propofol. In the S group, sevoflurane was administered for 72h and then changed to propofol for the remaining 36h in order to observe the kinetics of fluoride after discontinuation of sevoflurane. Serum creatinine was the primary outcome variable, but inorganic fluoride concentrations and other renal, hepatic, and cardiorespiratory variables were also measured. RESULTS: Both groups of animals were comparable at baseline. No differences were found between the two groups for plasma creatinine and urea or creatinine clearance throughout the study. Fluoride levels were significantly higher in the sevoflurane group. No correlation was found between inorganic fluoride and serum creatinine values. No significant differences were observed for hepatic function. Hemodynamic, respiratory, and blood gas variables were comparable between the groups. CONCLUSIONS: Long-term sedation with sevoflurane using AnaConDa™ or propofol does not negatively affect renal or hepatic function.

[Intracranial hypertension related to sedation with sevoflurane using the AnaConDa(®) device in a patient with severe traumatic brain injury]. / Hipertensión endocraneal asociada a la sedación con sevoflurano mediante el dispositivo AnaConDa(®)en un paciente con traumatismo craneoencefálico severo.

Sedation in neurocritical patients remains a challenge as there is no drug that meets all the requirements. Since the appearance of the AnaConDa(®) device, and according to the latest recommendations, sevoflurane has become an alternative for patients with brain injury. The use of AnaConDa(®) produces an increase in the anatomical dead space that leads to a decrease in alveolar ventilation. If the decrease in the alveolar ventilation is not offset by an increase in minute volume, there will be an increase in PaCO2. We report the case of a patient with severe traumatic brain injury who suffered an increase in intracranial pressure as a result of increased PaCO2 after starting sedation with the AnaConDa(®) device.