Conscious sedation in the emergency department: the value of capnography and pulse oximetry

Korean clinical practice guidelines for diagnostic and procedural sedation

Safe and effective sedation depends on various factors, such as the choice of sedatives, sedation techniques used, experience of the sedation provider, degree of sedation-related education and training, equipment and healthcare worker availability, the patient's underlying diseases, and the procedure being performed. The purpose of these evidence-based multidisciplinary clinical practice guidelines is to ensure the safety and efficacy of sedation, thereby contributing to patient safety and ultimately improving public health. These clinical practice guidelines comprise 15 key questions covering various topics related to the following: the sedation providers; medications and equipment available; appropriate patient selection; anesthesiologist referrals for high-risk patients; pre-sedation fasting; comparison of representative drugs used in adult and pediatric patients; respiratory system, cardiovascular system, and sedation depth monitoring during sedation; management of respiratory complications during pediatric sedation; and discharge criteria. The recommendations in these clinical practice guidelines were systematically developed to assist providers and patients in sedation-related decision making for diagnostic and therapeutic examinations or procedures. Depending on the characteristics of primary, secondary, and tertiary care institutions as well as the clinical needs and limitations, sedation providers at each medical institution may choose to apply the recommendations as they are, modify them appropriately, or reject them completely.

Guidelines for Monitoring and Management of Pediatric Patients Before, During, and After Sedation for Diagnostic and Therapeutic Procedures

The safe sedation of children for procedures requires a systematic approach that includes the following: no administration of sedating medication without the safety net of medical/dental supervision, careful presedation evaluation for underlying medical or surgical conditions that would place the child at increased risk from sedating medications, appropriate fasting for elective procedures and a balance between the depth of sedation and risk for those who are unable to fast because of the urgent nature of the procedure, a focused airway examination for large (kissing) tonsils or anatomic airway abnormalities that might increase the potential for airway obstruction, a clear understanding of the medication's pharmacokinetic and pharmacodynamic effects and drug interactions, appropriate training and skills in airway management to allow rescue of the patient, age- and size-appropriate equipment for airway management and venous access, appropriate medications and reversal agents, sufficient numbers of appropriately trained staff to both carry out the procedure and monitor the patient, appropriate physiologic monitoring during and after the procedure, a properly equipped and staffed recovery area, recovery to the presedation level of consciousness before discharge from medical/dental supervision, and appropriate discharge instructions. This report was developed through a collaborative effort of the American Academy of Pediatrics and the American Academy of Pediatric Dentistry to offer pediatric providers updated information and guidance in delivering safe sedation to children.

Recommendations for good practice for sedation in assisted conception

Conscious sedation is a commonly used approach to provide pain relief during transvaginal oocyte retrieval. It has been shown to be effective with high levels of acceptability and patient satisfaction. Fundamental Standards and Development Standards in safe sedation practice have been set out by the Royal College of Anaesthetists and they recommend that Royal Colleges, in association with the relevant sub-specialty organizations, should develop guidelines on sedation methods appropriate to clinical practice in their sphere of influence. This Policy and Practice paper outlines the human resources and equipment necessary to optimize patients' safety for the administration of intravenous (I.V.) sedation in assisted conception units, based on the most current evidence and guidance available.

Flexible Bronchoscopy Under Bronchoscopist-Administered Moderate Sedation Versus General Anesthesia: A Comparative Study in Children

Background: Flexible bronchoscopy (FB) can be performed under bronchoscopist administered moderate sedation (BAMS) with a midazolam/fentanyl combination or general anesthesia (GA). However, the outcome of BAMS has not been well established in children. Currently, most of the centers prefer FB under GA. Both techniques have their advantages and disadvantages with implications for safety, complications, and diagnostic yield. The primary objective of our study was to evaluate the safety, time efficiency, and cost-effectiveness of FB under BAMS as compared with FB under GA in a similar setting. Methods: We performed a retrospective chart review to compare BAMS versus GA for FB in children. We recruited BAMS children (n = 295) from University of Florida (UF) Health Shands Children's Hospital, and GA children (n = 100) from Penn State Children's Hospital (PSHCH). Both the groups had similar indications, complexities, and procedural environments. Comparisons of various time-intervals including preprocedure time, sedation-induction time, scope time, and post-procedure time among different BAMS versus GA age-groups were the primary outcomes. The secondary outcomes were the determination of the rates of complications, the dosages of sedative/anesthetic, cost-effectiveness, and sedation patterns under BAMS. Results: FB under BAMS required significantly higher preprocedure times and sedation-induction times (P < 0.001** and P < 0.001** respectively) but shorter scope and post-procedure times compared with the GA group times (P < 0.001** and P < 0.001** respectively). Younger children had a deeper level of sedation for an extended period under BAMS. The costs for the sedation services and the complication rates were lower in the BAMS group compared with the GA group. Conclusion: Our study demonstrated the feasibility of BAMS in children. FB under BAMS had an advantage of lower cost and fewer procedural complications compared with FB under GA. Despite that, the safety of BAMS could not be conclusively established from this retrospective study. Moreover, BAMS can potentially compromise the diagnostic yield because the bronchoscopist is also responsible for monitoring sedation and managing the airway.

Practice Guidelines for Moderate Procedural Sedation and Analgesia 2018

Supplemental Digital Content is available in the text.

Capnography versus standard monitoring for emergency department procedural sedation and analgesia

BACKGROUND

Procedural sedation and analgesia (PSA) is used frequently in the emergency department (ED) to facilitate painful procedures and interventions. Capnography, a monitoring modality widely used in operating room and endoscopy suite settings, is being used more frequently in the ED setting with the goal of reducing cardiopulmonary adverse events. As opposed to settings outside the ED, there is currently no consensus on whether the addition of capnography to standard monitoring modalities reduces adverse events in the ED setting.

OBJECTIVES

To assess whether capnography in addition to standard monitoring (pulse oximetry, blood pressure and cardiac monitoring) is more effective than standard monitoring alone to prevent cardiorespiratory adverse events (e.g. oxygen desaturation, hypotension, emesis, and pulmonary aspiration) in ED patients undergoing PSA.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (2016, Issue 8), and MEDLINE, Embase, and CINAHL to 9 August 2016 for randomized controlled trials (RCTs) and quasi-randomized trials of ED patients requiring PSA with no language restrictions. We searched meta-registries (www.controlled-trials.com, www.clinicalstudyresults.org, and clinicaltrials.gov) for ongoing trials (February 2016). We contacted the primary authors of included studies as well as scientific advisors of capnography device manufacturers to identify unpublished studies (February 2016). We handsearched conference abstracts of four organizations from 2010 to 2015.

SELECTION CRITERIA

We included any RCT or quasi-randomized trial comparing capnography and standard monitoring to standard monitoring alone for ED patients requiring PSA.

DATA COLLECTION AND ANALYSIS

Two authors independently performed study selection, data extraction, and assessment of methodological quality for the 'Risk of bias' tables. An independent researcher extracted data for any included studies that our authors were involved in. We contacted authors of included studies for incomplete data when applicable. We used Review Manager 5 to combine data and calculate risk ratios (RR) and 95% confidence intervals (CI) using both random-effects and fixed-effect models.

MAIN RESULTS

We identified three trials (κ = 1.00) involving 1272 participants. Comparing the capnography group to the standard monitoring group, there were no differences in the rates of oxygen desaturation (RR 0.89, 95% CI 0.48 to 1.63; n = 1272, 3 trials; moderate quality evidence) and hypotension (RR 2.36, 95% CI 0.98 to 5.69; n = 986, 1 trial; moderate quality evidence). There was only one episode of emesis recorded without significant difference between the groups (RR 3.10, 95% CI 0.13 to 75.88, n = 986, 1 trial; moderate quality evidence). The quality of evidence for the primary outcomes was moderate with downgrades primarily due to heterogeneity and reporting bias.There were no differences in the rate of airway interventions performed (RR 1.26, 95% CI 0.94 to 1.69; n = 1272, 3 trials; moderate quality evidence). In the subgroup analysis, we found a higher rate of airway interventions for adults in the capnography group (RR 1.44, 95% CI 1.16 to 1.79; n = 1118, 2 trials; moderate quality evidence) with a number needed to treat for an additional harmful outcome of 12. Although statistical heterogeneity was reduced, there was moderate quality of evidence due to outcome definition heterogeneity and limited reporting bias. None of the studies reported recovery time.

AUTHORS' CONCLUSIONS

There is a lack of convincing evidence that the addition of capnography to standard monitoring in ED PSA reduces the rate of clinically significant adverse events. Evidence was deemed to be of moderate quality due to population and outcome definition heterogeneity and limited reporting bias. Our review was limited by the small number of clinical trials in this setting.

Guidelines for Monitoring and Management of Pediatric Patients Before, During, and After Sedation for Diagnostic and Therapeutic Procedures: Update 2016

The safe sedation of children for procedures requires a systematic approach that includes the following: no administration of sedating medication without the safety net of medical/dental supervision, careful presedation evaluation for underlying medical or surgical conditions that would place the child at increased risk from sedating medications, appropriate fasting for elective procedures and a balance between the depth of sedation and risk for those who are unable to fast because of the urgent nature of the procedure, a focused airway examination for large (kissing) tonsils or anatomic airway abnormalities that might increase the potential for airway obstruction, a clear understanding of the medication's pharmacokinetic and pharmacodynamic effects and drug interactions, appropriate training and skills in airway management to allow rescue of the patient, age- and size-appropriate equipment for airway management and venous access, appropriate medications and reversal agents, sufficient numbers of staff to both carry out the procedure and monitor the patient, appropriate physiologic monitoring during and after the procedure, a properly equipped and staffed recovery area, recovery to the presedation level of consciousness before discharge from medical/dental supervision, and appropriate discharge instructions. This report was developed through a collaborative effort of the American Academy of Pediatrics and the American Academy of Pediatric Dentistry to offer pediatric providers updated information and guidance in delivering safe sedation to children.

End-tidal capnometry during emergency department procedural sedation and analgesia: a randomized, controlled study

BACKGROUND

This prospective, randomized trial was undertaken to evaluate the utility of adding end-tidal capnometry (ETC) to pulse oximetry (PO) in patients undergoing procedural sedation and analgesia (PSA) in the emergency department (ED).

METHODS

The patients were randomized to monitoring with or without ETC in addition to the current standard of care. Primary endpoints included respiratory adverse events, with secondary endpoints of level of sedation, hypotension, other PSA-related adverse events and patient satisfaction.

RESULTS

Of 986 patients, 501 were randomized to usual care and 485 to additional ETC monitoring. In this series, 48% of the patients were female, with a mean age of 46 years. Orthopedic manipulations (71%), cardioversion (12%) and abscess incision and drainage (12%) were the most common procedures, and propofol and fentanyl were the sedative/analgesic combination used for most patients. There was no difference in patients experiencing de-saturation (SaO2<90%) between the two groups; however, patients in the ETC group were more likely to require airway repositioning (12.9% vs. 9.3%, P=0.003). Hypotension (SBP<100 mmHg or <85 mmHg if baseline <100 mmHg) was observed in 16 (3.3%) patients in the ETC group and 7 (1.4%) in the control group (P=0.048).

CONCLUSIONS

The addition of ETC does not appear to change any clinically significant outcomes. We found an increased incidence of the use of airway repositioning maneuvers and hypotension in cases where ETC was used. We do not believe that ETC should be recommended as a standard of care for the monitoring of patients undergoing PSA.

A comparison of linear and logarithmic auditory tones in pulse oximeters

This study compared the ability of forty anaesthetists to judge absolute levels of oxygen saturation, direction of change, and size of change in saturation using auditory pitch and pitch difference in two laboratory-based studies that compared a linear pitch scale with a logarithmic scale. In the former the differences in saturation become perceptually closer as the oxygenation level becomes higher whereas in the latter the pitch differences are perceptually equivalent across the whole range of values. The results show that anaesthetist participants produce significantly more accurate judgements of both absolute oxygenation values and size of oxygenation level difference when a logarithmic, rather than a linear, scale is used. The line of best fit for the logarithmic function was also closer to x = y than for the linear function. The results of these studies can inform the development and standardisation of pulse oximetry tones in order to improve patient safety.

A comparative evaluation of capnometry versus pulse oximetry during procedural sedation and analgesia on room air

Objective:

Important questions remain regarding how best to monitor patients during procedural sedation and analgesia (PSA). Capnometry can detect hypoventilation and apnea, yet it is rarely used in emergency patients. Even the routine practice of performing preoxygenation in low-risk patients is controversial, as supplementary oxygen can delay the detection of respiratory depression by pulse oximetry. The purpose of this study was to determine whether the capnometer or the pulse oximeter would first detect respiratory events in adults breathing room air.

Methods:

During a randomized clinical trial comparing fentanyl with low-dose ketamine for PSA with titrated propofol, patients were monitored using pulse oximetry and continuous oral–nasal sampled capnography. Supplemental oxygen was administered only for oxygen desaturation. Sedating physicians identified prespecified respiratory events, including hypoventilation (end-tidal carbon dioxide &gt; 50 mm Hg, rise of 10 mm Hg from baseline or loss of waveform) and oxygen desaturation (pulse oximetry &lt; 92%). These events and their timing were corroborated by memory data retrieved from the monitors.

Results:

Of 63 patients enrolled, 57% (36) developed brief oxygen desaturation at some point during the sedation. All responded to oxygen, stimulation or interruption of propofol. Measurements of end-tidal carbon dioxide varied substantially between and within patients before study intervention. Hypoventilation (19 patients, 30%) was only weakly associated with oxygen desaturation (crude odds ratio 1.4 [95% confidence interval 0.47 to 4.3]), and preceded oxygen desaturation in none of the 12 patients in whom both events occurred (median lag 1:50 m:ss [interquartile range 0:01 to 3:24 m:ss]).

Conclusion:

During PSA in adults breathing room air, desaturation detectable by pulse oximeter usually occurs before overt changes in capnometry are identified.

A randomized controlled trial of capnography during sedation in a pediatric emergency setting

OBJECTIVE

Data suggest that capnography is a more sensitive measure of ventilation than standard modalities and detects respiratory depression before hypoxemia occurs. We sought to determine if adding capnography to standard monitoring during sedation of children increased the frequency of interventions for hypoventilation, and whether these interventions would decrease the frequency of oxygen desaturations.

METHODS

We enrolled 154 children receiving procedural sedation in a pediatric emergency department. All subjects received standard monitoring and capnography, but were randomized to whether staff could view the capnography monitor (intervention) or were blinded to it (controls). Primary outcome were the rate of interventions provided by staff for hypoventilation and the rate of oxygen desaturation less than 95%.

RESULTS

Seventy-seven children were randomized to each group. Forty-five percent had at least 1 episode of hypoventilation. The rate of hypoventilation per minute was significantly higher among controls (7.1% vs 1.0%, P = .008). There were significantly fewer interventions in the intervention group than in the control group (odds ratio, 0.25; 95% confidence interval [CI], 0.13-0.50). Interventions were more likely to occur contemporaneously with hypoventilation in the intervention group (2.26; 95% CI, 1.34-3.81). Interventions not in time with hypoventilation were associated with higher odds of oxygen desaturation less than 95% (odds ratio, 5.31; 95% CI, 2.76-10.22).

CONCLUSION

Hypoventilation is common during sedation of pediatric emergency department patients. This can be difficult to detect by current monitoring methods other than capnography. Providers with access to capnography provided fewer but more timely interventions for hypoventilation. This led to fewer episodes of hypoventilation and of oxygen desaturation.

The role of capnography in endoscopy patients undergoing nurse-administered propofol sedation: a randomized study

OBJECTIVE. Standard benzodiazepine/opioid cocktail has proven inferior to propofol sedation during complicated endoscopic procedures and in low-tolerance patients. Propofol is a short-acting hypnotic with a potential risk of respiratory depression at levels of moderate to deep sedation. The existing literature on capnography for endoscopy patients sedated with nurse-administered propofol sedation (NAPS) is limited. Can the addition of capnography to standard monitoring during endoscopy with NAPS reduce the number, duration, and level of hypoxia. MATERIALS AND METHODS. This study was a randomized controlled trial with an intervention group (capnography) and a control group (without capnography). Eligible subjects were consecutive patients for endoscopy at Gentofte Hospital compliant with the criteria of NAPS. RESULTS. Five hundred and forty patients, 263 with capnography and 277 without capnography, were included in the analysis. The number and total duration of hypoxia was reduced by 39.3% and 21.1% in the intervention group compared to the control group (p > 0.05). No differences in actions taken against insufficient respiration were found. Changes in end-tidal carbon dioxide (R = 0.177, p-value < 0.001) and respiratory rate (R = 0.092, p-value < 0.001) were correlated to oxygen saturation (SpO2) up to 36 s prior to changes in SpO2. CONCLUSIONS. Capnography seems to reduce the number and duration of hypoxia in NAPS patients (p > 0.05). Capnography is able to detect insufficient respiration that may lead to hypoxia prior to changes in pulse oximetry. However, due to a limited clinical benefit and additional costs associated with capnography, we do not find capnography necessary during the use of NAPS.

Capnography for the nonintubated patient in the emergency setting

BACKGROUND

Multiple studies illustrate the benefits of waveform capnography in the nonintubated patient. This type of monitoring is routinely used by anesthesia providers to recognize ventilation issues. Its role in the administration of deep sedation is well defined. Prehospital providers embrace the ease and benefit of monitoring capnography. Currently, few community-based emergency physicians utilize capnography with the nonintubated patient.

OBJECTIVE

This article will identify clinical areas where monitoring end-tidal carbon dioxide is beneficial to the emergency provider and patient.

DISCUSSION

Capnography provides real-time data to aid in the diagnosis and patient monitoring for patient states beyond procedural sedation and bronchospasm. Capnographic changes provide valuable information in such processes as diabetic ketoacidosis, seizures, pulmonary embolism, and malignant hyperthermia.

CONCLUSIONS

Capnography is a quick, low-cost method of enhancing patient safety with the potential to improve the clinician's diagnostic power.

[Measurement of carbon dioxide in emergency medicine]

Expiratory carbon dioxide (CO(2)) monitoring is a valuable tool in the prehospital setting. Recent reports of misplaced endotracheal tubes in the prehospital setting make it important to ensure that tube placement is verified by CO(2) monitoring. The Euronorm 2007:1789 made provision of capnometry mandatory for all medical vehicles. However, the frequency of utilization of CO(2) monitoring after securing the airway and in patients with respiratory insufficiency is low. This article covers the terminology, physiology, technology and clinical applications of CO(2) monitoring. Monitoring of cardiac output and the efficiency of cardiopulmonary resuscitation are described and the article also highlights the importance of CO(2) monitoring in patients with severe head trauma as well as restrictive and obstructive pulmonary disorders.

Pediatric procedural sedation and analgesia

Procedural sedation and analgesia (PSA) is an evolving field in pediatric emergency medicine. As new drugs breach the boundaries of anesthesia in the Pediatric Emergency Department, parents, patients, and physicians are finding new and more satisfactory methods of sedation. Short acting, rapid onset agents with little or no lingering effects and improved safety profiles are replacing archaic regimens. This article discusses the warning signs and areas of a patient's medical history that are particularly pertinent to procedural sedation and the drugs used. The necessary equipment is detailed to provide the groundwork for implementing safe sedation in children. It is important for practitioners to familiarize themselves with a select few of the PSA drugs, rather than the entire list of sedatives. Those agents most relevant to PSA in the pediatric emergency department are presented.

Detection of hypoventilation by capnography and its association with hypoxia in children undergoing sedation with ketamine

OBJECTIVES

Hypopneic hypoventilation, a decrease in tidal volume without a change in respiratory rate, is not easily detected by standard monitoring practices during sedation but can be detected by capnography. Our goal was to determine the frequency of hypopneic hypoventilation and its association with hypoxia in children undergoing sedation with ketamine.

METHODS

Children who received intravenous ketamine with or without midazolam for sedation in a pediatric emergency department were prospectively enrolled. Heart rate, respiratory rate, pulse oximetry, and end-tidal carbon dioxide (ET(CO2)) levels were recorded every 30 seconds.

RESULTS

Fifty-eight subjects were included in this study. Fifty percent of subjects had recorded ET(CO2) values less than 30 mm Hg without a rise in respiratory rate. Twenty-eight percent of subjects experienced a decrease in pulse oximetry less than 95%. Patients who experienced a persistent decrease in ET(CO2) at least 30 seconds in length were much more likely to have a persistent decrease in pulse oximetry than those with normal or transient decreases in ET(CO2) (relative risk, 6.6; 95% confidence interval, 1.4-30.5). Decreases in ET(CO2) occurred on an average of 3.7 minutes before decreases in pulse oximetry.

CONCLUSIONS

Hypopneic hypoventilation as detected by capnography is common in children undergoing sedation with ketamine with or without midazolam. Hypoxia is frequently preceded by low ET(CO2) levels. Further studies are needed to determine if the addition of routine monitoring with capnography can reduce the frequency of hypoxia in children undergoing sedation.

Does end tidal CO2 monitoring during emergency department procedural sedation and analgesia with propofol decrease the incidence of hypoxic events? A randomized, controlled trial

STUDY OBJECTIVE

We determine whether the use of capnography is associated with a decreased incidence of hypoxic events than standard monitoring alone during emergency department (ED) sedation with propofol.

METHODS

Adults underwent ED propofol sedation with standard monitoring (pulse oximetry, cardiac and blood pressure) and capnography and were randomized into a group in which treating physicians had access to the capnography and a blinded group in which they did not. All patients received supplemental oxygen (3 L/minute) and opioids greater than 30 minutes before. Propofol was dosed at 1.0 mg/kg, followed by 0.5 mg/kg as needed. Capnographic and SpO2 data were recorded electronically every 5 seconds. Hypoxia was defined as SpO2 less than 93%; respiratory depression, as end tidal CO2 (ETCO2) greater than 50 mm Hg, ETCO2 change from baseline of 10%, or loss of the waveform.

RESULTS

One hundred thirty-two subjects were evaluated and included in the final analysis. We observed hypoxia in 17 of 68 (25%) subjects with capnography and 27 of 64 (42%) with blinded capnography (P=.035; difference 17%; 95% confidence interval 1.3% to 33%). Capnography identified all cases of hypoxia before onset (sensitivity 100%; specificity 64%), with the median time from capnographic evidence of respiratory depression to hypoxia 60 seconds (range 5 to 240 seconds).

CONCLUSION

In adults receiving ED propofol sedation, the addition of capnography to standard monitoring reduced hypoxia and provided advance warning for all hypoxic events.

Capnography for Procedural Sedation and Analgesia in the Emergency Department

Although it is standard of care for patient safety monitoring in anesthesia, capnography is not routinely used for emergency department procedural sedation and analgesia. We discuss the use of capnography as a diagnostic monitoring modality for procedural sedation and analgesia, focusing on the physiology and interpretation of the CO2 waveform and recognition of normal, abnormal, and drug-induced ventilatory patterns.

The Utility of Supplemental Oxygen During Emergency Department Procedural Sedation and Analgesia With Midazolam and Fentanyl: A Randomized, Controlled Trial

STUDY OBJECTIVE

To determine whether supplemental oxygen reduces the incidence of hypoxia by 20% in study patients receiving midazolam and fentanyl for emergency department procedural sedation and analgesia.

METHODS

Patients were randomized to receive either supplemental oxygen or compressed air by nasal cannula at 2 L per minute. Physicians were blinded to the gas used and end-tidal carbon dioxide (ETCO2) data. Respiratory depression was defined a priori as oxygen saturation less than 90%, ETCO2 level greater than 50 mm Hg, an absolute change from baseline of 10 mm Hg, or loss of the ETCO2 waveform.

RESULTS

Of the 80 patients analyzed, 44 received supplemental oxygen and 36 received compressed air. Twenty supplemental oxygen patients and 19 compressed air patients met at least 1 criterion for respiratory depression. Six supplemental oxygen patients and 5 compressed air patients experienced hypoxia (P=.97; effect size 0%; 95% confidence interval -15% to +15%). Fourteen patients in each group met ETCO2 criteria for respiratory depression but were not hypoxic. Physicians identified respiratory depression in 8 of 11 patients who became hypoxic and 0 of 28 patients who met ETCO2 criteria for respiratory depression but who did not become hypoxic. There were no adverse events.

CONCLUSION

Supplemental oxygen did not reduce (or trend toward reducing) the incidence of hypoxia in patients moderately sedated with midazolam and fentanyl. However, our lower-than-expected rate of hypoxia limits the power of this comparison. Blinded capnography frequently identified respiratory depression undetected by the treating physicians.

Guidelines for monitoring and management of pediatric patients during and after sedation for diagnostic and therapeutic procedures: an update

The safe sedation of children for procedures requires a systematic approach that includes the following: no administration of sedating medication without the safety net of medical supervision; careful presedation evaluation for underlying medical or surgical conditions that would place the child at increased risk from sedating medications; appropriate fasting for elective procedures and a balance between depth of sedation and risk for those who are unable to fast because of the urgent nature of the procedure; a focused airway examination for large tonsils or anatomic airway abnormalities that might increase the potential for airway obstruction; a clear understanding of the pharmacokinetic and pharmacodynamic effects of the medications used for sedation, as well as an appreciation for drug interactions; appropriate training and skills in airway management to allow rescue of the patient; age- and size-appropriate equipment for airway management and venous access; appropriate medications and reversal agents; sufficient numbers of people to carry out the procedure and monitor the patient; appropriate physiologic monitoring during and after the procedure; a properly equipped and staffed recovery area; recovery to presedation level of consciousness before discharge from medical supervision; and appropriate discharge instructions. This report was developed through a collaborative effort of the American Academy of Pediatrics and the American Academy of Pediatric Dentistry to offer pediatric providers updated information and guidance in delivering safe sedation to children.

Does end-tidal carbon dioxide monitoring detect respiratory events prior to current sedation monitoring practices?

OBJECTIVES

The value of ventilation monitoring with end-tidal carbon dioxide (ETCO2) to anticipate acute respiratory events during emergency department (ED) procedural sedation and analgesia (PSA) is unclear. The authors sought to determine if ETCO2 monitoring would reveal findings indicating an acute respiratory event earlier than indicated by current monitoring practices.

METHODS

The study included a prospective convenience sample of ED patients undergoing PSA. Clinicians performed ED PSA procedures with generally accepted patient monitoring, including oxygen saturation (SpO2), and clinical ventilation assessment. A study investigator recorded ETCO2 levels and respiratory events during each PSA procedure, with clinical providers blinded to ETCO(2) levels. Acute respiratory events were defined as SpO2 < or =92%, increases in the amount of supplemental oxygen provided, use of bag-valve mask or oral/nasal airway for ventilatory assistance, repositioning or airway alignment maneuvers, and use of physical or verbal means to stimulate patients with depressed ventilation or apnea, and reversal agent administration.

RESULTS

Enrollment was stopped after independent review of 20 acute respiratory events in 60 patient sedation encounters (33%). Abnormal ETCO2 findings were documented in 36 patients (60%). Seventeen patients (85%) with acute respiratory events demonstrated ETCO2 findings indicative of hypoventilation or apnea during PSA. Abnormal ETCO2 findings were documented before changes in SpO2 or clinically observed hypoventilation in 14 patients (70%) with acute respiratory events.

CONCLUSIONS

Abnormal ETCO2 findings were observed with many acute respiratory events. A majority of patients with acute respiratory events had ETCO2 abnormalities that occurred before oxygen desaturation or observed hypoventilation.

Pediatric procedural sedation and analgesia

Children often present with painful conditions that require painful interventions. Procedural sedation and analgesia refers to the pharmacologic technique of managing a child's pain and anxiety. Procedural sedation is a safe, effective, and humane way to facilitate appropriate medical care. It is important to distinguish the goals for the procedural sedation, pain relief or anxiolysis or both. Different medications and combinations of medications can be used to achieve the desired effect. It is also important to keep in mind the possible adverse reactions and side effects associated with each medication when choosing the sedation cocktail.

Novel monitoring techniques for use with procedural sedation

PURPOSE OF REVIEW

A variety of pharmacologic agents used for procedural sedation in children to reduce pain and anxiety may produce respiratory depression and hypotension. Although standard monitoring guidelines include oxygen saturation, this measurement is limited as a guide to respiratory function. This review discusses two new monitoring techniques recently introduced to the pediatric emergency department that facilitate procedural sedation and reduce potential adverse effects of the medications administered.

RECENT FINDINGS

Capnography via an end-tidal carbon dioxide monitor measures carbon dioxide concentrations during ventilation. This measurement is independent of oxygen saturation and thereby aids the clinician in identifying hypoventilation and apnea in the sedated patient at an earlier stage than conventional monitoring. The bispectral index monitor objectively measures the depth of sedation by analyzing electroencephalogram signals from a cutaneous probe. This tool enables the physician to titrate sedative medications to a desired effect and thereby reduce the risks associated with oversedation.

SUMMARY

Studies have illustrated the use of both devices as adjuncts to current standard monitoring of children in the outpatient setting. These modalities will facilitate the efficacy of procedural sedation in children and improve safety by enabling early recognition of hypoventilation and by reducing the risk of oversedation in children undergoing procedural sedation.

Procedural Sedation and Analgesia in the Emergency Department: What Are the Risks?

The practitioner of emergency medicine is routinely faced with patients in need of emergent procedures and pain control and sedation. Our challenge is to make our patients' experiences as painless and as safe as possible, while maximizing our ability to perform the procedure at hand; this is not always an easy task given the propensity of each human body to react differently to interventions and stimuli. We can best meet this challenge by understanding how our patients and pharmaceutical agents intermingle in the risk-benefit equation we formulate before starting our "experiment." Coupling this information with fundamentally sound patient care and monitoring will minimize bad experiences with PSA for both the patient and practitioner.

Contemporary trends in pediatric sedation and analgesia

The ability to provide safe, effective procedural sedation and analgesia is a necessary skill for physicians caring for the acutely ill or injured pediatric patient. They physician should be familiar with the agent(s) chosen, including dosage, duration, adverse effects, and contraindications. The choice of agent and regimen should be individualized for the patient and situation. Successful outcomes depend on performing careful pre- and post-sedation evaluations, following appropriate monitoring and equipment guidelines, and having the knowledge and skills to manage any adverse cardiorespiratory event.

Capnography during sedation/analgesia in the pediatric emergency department

OBJECTIVE

To measure changes in end-tidal carbon dioxide levels (ETCO2) during sedation/analgesia in pediatric patients and to describe ETCO2 changes associated with different sedation strategies.

METHODS

This was a prospective, observational patient series in an urban pediatric emergency department (PED). Participants included 106 children with a mean age of 6.8 years. (range 1.2-16.6 years). Sedation/analgesia was given for fracture reduction (55%), laceration repair (37%), abscess incision and drainage (4%), and lumbar puncture (LP) (4%). Medications included fentanyl, morphine, ketamine, and midazolam. Continuous ETCO2 waveforms were recorded via a Capnogard ETCO2 Monitor. Oxygen saturation was recorded using a Nelcor N-200 pulse oximeter. Recording began prior to sedation and continued until the patient was awake or when it was necessary to remove the patient from the monitor for further medical care. Each record was analyzed for peak ETCO2 and averaged over five consecutive breaths, before and after the administration of medications. The main outcome measure was the change in ETCO2 levels.

RESULTS

The mean increase in ETCO2 was 6.7 mmHg (P is included in, 0.00001; range: +0.16 to +22.3). ETCO2 increased by 3.2 mmHg (95% CI = 2.2-4.2) for midazolam alone, 5.4 mmHg (95% CI = 4.5-6.4) for midazolam and ketamine, and 8.8 mmHg (95% CI = 7.4-10.2) for midazolam and opiate. Two patients had transient SpO2 desaturations below 93%, which corrected with stimulation.

CONCLUSIONS

Commonly used agents for pediatric sedation result in significant increases in ETCO2. ETCO2 is a useful adjunct in assessing ventilation and may serve as an objective research tool for assessing different sedation strategies.

Pharmacology of emergency department pain management and conscious sedation

The endpoints of sedation and analgesia have been more difficult than traditional physiologic parameters to measure adequately. Several clinical scoring systems have been developed in an attempt to provide more consistent and objective assessments of sedation, but the few that have been validated are cumbersome to use in the clinical setting and cannot accurately determine subtle changes in the level of sedation. Recent developments in EEG monitoring, particularly one using bispectral (BIS) analysis of the EEG signal obtained through a noninvasive forehead "lead," are promising. BIS monitoring has been used as a reliable measure of depth of midazolam-induced sedation during general anesthesia. Anesthesiologists have used this technology to prevent awareness during paralysis. One recently completed but as yet unpublished study in the ED demonstrated a high correlation with traditional sedation scales and found the device easy to use (UNC Hospitals Department of Emergency Medicine, personal communication, 1999). It is anticipated that with BIS monitoring, in combination with titratable, short-acting agents, appropriate levels of sedation can be more easily achieved while minimizing associated complications and duration of ED stay.

Carbon dioxide kinetics and capnography during critical care

Greater understanding of the pathophysiology of carbon dioxide kinetics during steady and nonsteady state should improve, we believe, clinical care during intensive care treatment. Capnography and the measurement of end-tidal partial pressure of carbon dioxide (PETCO2) will gradually be augmented by relatively new measurement methodology, including the volume of carbon dioxide exhaled per breath (VCO2,br) and average alveolar expired PCO2. Future directions include the study of oxygen kinetics.

A comparison of carbon dioxide monitoring and oxygenation between facemask and divided nasal cannula

The divided nasal cannula is a device recently released in Australia that couples oxygen delivery and end-tidal carbon dioxide (PETCO2) monitoring. This study compares the accuracy of PETCO2 measurements by the divided nasal cannula and those measured by a modified facemask (as currently used in this institution), with arterial partial pressure of carbon dioxide (PaCO2). In this crossover study, 30 patients who had arterial lines as part of their routine monitoring were given oxygen via nasal cannula and facemask preoperatively. The PETCO2 was measured with each device and a simultaneous PaCO2 and PaO2 measured after equilibration. The results demonstrate a significant difference between the PETCO2 as measured by each technique. The divided nasal cannula more accurately reflects PaCO2 (mean arterial to end expired gradient of 5 mmHg) and provides a more representative trace when compared to a traditional facemask system. Both methods provided adequate oxygenation.

Life-threatening brain failure and agitation in the intensive care unit

The modern intensive care unit (ICU) has evolved into an area where mortality and morbidity can be reduced by identification of unexpected hemodynamic and ventilatory decompensations before long-term problems result. Because intensive care physicians are caring for an increasingly heterogeneous population of patients, the indications for aggressive monitoring and close titration of care have expanded. Agitated patients are proving difficult to deal with in nonmonitored environments because of the unpredictable consequences of the agitated state on organ systems. The severe agitation state that is associated with ethanol withdrawal and delirium tremens (DT) is examined as a model for evaluating the efficacy of the ICU environment to ensure consistent stabilization of potentially life-threatening agitation and delirium.

Procedural sedation and analgesia in the emergency department. Canadian Consensus Guidelines

Procedural sedation and analgesia are core skills in emergency medicine. Various specialty societies have developed guidelines for procedural sedation, each reflecting the perspective of the specialty group. Emergency practitioners are most likely to embrace guidelines developed by people who understand emergency department (ED) skills, procedures, conditions, and case mix. Recognizing this, the Canadian Association of Emergency Physicians (CAEP) determined the need to establish guidelines for procedural sedation in the ED. In March, 1996, a national emergency medicine (EM) working committee, representing adult and pediatric emergency physicians, was established. This committee teleconferenced with representatives of the Canadian Anesthetic Society (CAS) to identify problems, perspectives, and controversial issues, and to define a process for guideline development. The EM committee subsequently reviewed existing literature, determined levels of evidence, and developed the document, which evolved based on feedback from the CAS and CAEP Standards Committees. The final version was approved by the CAEP Standards Committee and the CAEP Board of Directors, then submitted for peer review. These guidelines discuss the goals, definitions, and principles of ED sedation, and make recommendations for pre-sedation preparation, patient fasting, physician skills, equipment and monitoring requirements, and post-sedation care. The guidelines are aimed at non-anesthesiologists practicing part-time or full-time emergency medicine. They are applicable to ED patients receiving parenteral analgesia or sedation for painful or anxiety-provoking procedures. They are intended to increase the safety of procedural sedation in the ED.

End-tidal carbon dioxide monitoring in emergency medicine, Part 2: Clinical applications

End-tidal carbon dioxide (PetCO2) monitoring is becoming more common in both the ED and the out-of-hospital setting. Its main use has been as an aid when confirming endotracheal intubation. Other uses in the ED include monitoring CPR efforts and monitoring the ventilatory and hemodynamic status of intubated and nonintubated patients. In addition, future uses may include using PetCO2 as an adjunct when monitoring the status of asthma treatment, when making the diagnosis of pulmonary embolism, and when measuring cardiac output noninvasively. This article reviews these specific uses of PetCO2 monitoring in emergency medicine.