Capnography during sedation/analgesia in the pediatric emergency department

Capillary blood gas in infants with bronchiolitis: Can end-tidal capnography replace it?

OBJECTIVES

To explore the predictive ability of capillary blood gas (CBG) pCO₂ for respiratory decompensation in infants aged ≤6 months with bronchiolitis admitted from the emergency department; to determine whether end-tidal CO₂ (etCO₂) capnography can serve as a less invasive substitute for CBG pCO₂.

STUDY DESIGN

This was a prospective cohort study of previously healthy infants aged ≤6 months admitted for bronchiolitis from the emergency department (ED). Initial CBG pCO₂ and etCO₂ capnography were obtained in the ED prior to inpatient admission. Simple logistic regression modeling was used to examine the associations of CBG pCO₂ and etCO₂ capnography with respiratory decompensation. Pearson's correlation measured the relationship between CBG pCO₂ and etCO₂ capnography.

RESULTS

Of 134 patients, 61 had respiratory decompensation. There was a significant association between CBG pCO₂ and respiratory decompensation (OR = 1.07, p = 0.003), even after outlying values were excluded (OR = 1.06, p = 0.005). End tidal CO₂ capnography was not significantly associated with decompensation (OR = 1.02, p = 0.17), even after outlying values were excluded (OR = 1.02, p = 0.24). There was a moderate correlation between etCO₂ capnography and CBG pCO₂ (r = 0.39, p < 0.001).

CONCLUSION

In infants with bronchiolitis, CBG pCO₂ provides an objective measure for predicting respiratory decompensation, and a single etCO₂ measurement should not replace its use.

Effects of Sedation and/or Sedation/Analgesic Drugs Administered during Central Venous Catheterization on the Level of End-tidal Carbon Dioxide Measured by Nasal Cannula in Our PICU

Aims and objectives

Sedatives and analgesics are commonly used in pediatric intensive care units during minor invasive procedures. Here, we aimed to measure the changes in end-tidal carbon dioxide (EtCO₂) levels with different sedation/analgesic drug administrations (midazolam, ketamine, midazolam + ketamine/fentanyl) during central venous catheterization.

Materials and methods

This prospective study included 44 patients who needed sedation/analgesia for central venous catheterization. Patients were sedated with midazolam, ketamine, or midazolam + fentanyl/ketamine. End-tidal carbon dioxide values were measured before and after sedation-analgesia with nasal cannula and recorded from the capnograph. Oxygen saturation (SO₂) was monitored by pulse oximetry. Whether respiratory depression occurred during the process was recorded.

Results

During the procedure, 15 (34%) patients were given 0.1 mg/kg dose of midazolam described as group I, 18 (41%) patients were given 1 mg/kg dose of ketamine only described as group II, and 11 (25%) patients who could not be effective sedated with a single sedative-analgesic agent were given either 1 mg/kg dose of ketamine or 2 μg/kg dose of fentanyl together with 0.1 mg/kg dose of midazolam described as group III. According to our findings, hypoxia (54.5%) and hypercarbia (45.5%) were detected higher in group III but it was not statistically significant (p = 0.255, p = 0.364). Hypercarbia was detected in 29.5% patients, in 62% of these patients hypercarbia was accompanied by hypoxia, and 38% had only hypercarbia. When presedation and postsedation EtCO₂ values were compared, we detected a statistically significant difference in all groups.

Conclusion

We detected hypercarbia unaccompanied by hypoxemia in 38% patients. And we think that we have identified these patients early due to measurement of EtCO₂ by nasal cannula. This study demonstrated that EtCO₂ monitoring via nasal cannula is a feasible and practical way to follow ventilation during sedation/analgesia.

How to cite this article

Aslan N, Yildizdas D, Horoz OO, Arslan D, Coban Y, Sertdemir Y. Effects of Sedation and/or Sedation/Analgesic Drugs Administered during Central Venous Catheterization on the Level of End-tidal Carbon Dioxide Measured by Nasal Cannula in Our PICU. Indian J Crit Care Med 2020;24(8):705-708.

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.

Randomized Clinical Trial Comparing Procedural Amnesia and Respiratory Depression Between Moderate and Deep Sedation With Propofol in the Emergency Department

OBJECTIVES

The objective was to determine if there is a difference in procedural amnesia and adverse respiratory events (AREs) between the target sedation levels of moderate (MS) and deep (DS) procedural sedation.

METHODS

This was a prospective, randomized clinical trial of consenting adult patients planning to undergo DS with propofol between March 5, 2015, and May 24, 2017. Patients were randomized to a target sedation level of MS or DS using the American Society of Anesthesiologist's definitions. Drug doses, vital signs, observer's assessment of alertness/sedation (OAAS) score, end-tidal CO₂ (ETCO₂ ), and the need for supportive airway maneuvers (SAMs; bag-valve mask use, repositioning, and stimulation to induce respirations) were monitored continuously. A standardized image was shown every 30 seconds starting 3 minutes before the procedure continuing until the patient had returned to baseline after the procedure. Recall and recognition of images were assessed 10 minutes after the sedation. Subclinical respiratory depression (RD) was defined as SaO₂ ≤ 91%, change in ETCO₂ ≥ 10 mm Hg, or absent ETCO₂ at any time. The occurrence of RD with a SAM was defined as an ARE. Patient satisfaction, pain, and perceived recollection and physician assessment of procedure difficulty were collected using visual analog scales (VASs). Data were analyzed with descriptive statistics and Wilcoxon rank-sum test.

RESULTS

A total of 107 patients were enrolled: 54 randomized to target MS and 53 to DS. Of the patients randomized to target MS, 50% achieved MS and 50% achieved DS. In the target DS group, 77% achieved DS and 23% achieved MS. The median total propofol dose (mg/kg) was lower in the MS group: MS 1.4 (95% confidence interval [CI] = 1.3-1.6, IQR = 1) versus DS 1.8 (95% CI = 1.6-2.0, IQR = 0.9). There were no differences in median OAAS during the procedure (MS 2.4 and DS 2.8), lowest OAAS (MS 2 and DS 2), percentage of images recalled (MS 4.7% vs. DS 3.8%, p = 0.73), or percentage of images recognized (MS 61.1% vs. DS 55%, p = 0.52). In the MS group, 41% patients had any AREs compared to 42% in the DS group (p = 0.77, 95% CI difference = -0.12 to 0.24). The total number of AREs was 23% lower in the MS group (p = 0.01, 95% CI = -0.41 to -0.04). There was no difference in patient-reported pain, satisfaction, or recollection VAS scores. Provider's rating of procedural difficulty and procedural success were similar in both groups.

CONCLUSIONS

Targeting MS or DS did not reliably result in the intended sedation level. Targeting MS, however, resulted in a lower rate of total AREs and fewer patients had multiple AREs with no difference in procedural recall. As seen in previous reports, patients who achieved MS had less AREs than those who achieved DS. Our study suggests that a target of MS provides adequate amnesia with less need for supportive airway interventions than a target level of DS, despite the fact that it often does not result in intended sedation level.

Capnography in the Emergency Department: A Review of Uses, Waveforms, and Limitations

BACKGROUND

Capnography has many uses in the emergency department (ED) and critical care setting, most commonly cardiac arrest and procedural sedation.

OBJECTIVE OF THE REVIEW

This review evaluates several indications concerning capnography beyond cardiac arrest and procedural sedation in the ED, as well as limitations and specific waveforms.

DISCUSSION

Capnography includes the noninvasive measurement of CO₂, providing information on ventilation, perfusion, and metabolism in intubated and spontaneously breathing patients. Since the 1990s, capnography has been utilized extensively for cardiac arrest and procedural sedation. Qualitative capnography includes a colorimetric device, changing color on the amount of CO₂ present. Quantitative capnography provides a numeric value (end-tidal CO₂), and capnography most commonly includes a waveform as a function of time. Conditions in which capnography is informative include cardiac arrest, procedural sedation, mechanically ventilated patients, and patients with metabolic acidemia. Patients with seizure, trauma, and respiratory conditions, such as pulmonary embolism and obstructive airway disease, can benefit from capnography, but further study is needed. Limitations include use of capnography in conditions with mixed pathophysiology, patients with low tidal volumes, and equipment malfunction. Capnography should be used in conjunction with clinical assessment.

CONCLUSIONS

Capnography demonstrates benefit in cardiac arrest, procedural sedation, mechanically ventilated patients, and patients with metabolic acidemia. Further study is required in patients with seizure, trauma, and respiratory conditions. It should only be used in conjunction with other patient factors and clinical assessment.

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.

Hypocapnia and hyperoxia induction using a hyperventilation protocol in electroconvulsive therapy

INTRODUCTION

Hyperventilation in electroconvulsive therapy sessions has been associated with seizure threshold, seizure characteristics, and cognitive effects. There is no consensus on the optimal procedure of applying hyperventilation manoeuvres during electroconvulsive therapy.

MATERIAL AND METHODS

Prospective evaluation of the effects of systematic use of hyperventilation manoeuvres with facial mask and capnography (protocolized hyperventilation [pHV]), on ventilation parameters and on seizures. The study included a sample of 130 sessions (65 performed according to hyperventilation standard practice and 65 successive sessions, with pHV) of 35 patients over a period of 10 weeks.

RESULTS

The pHV manoeuvres reduced exhaled CO₂ and increased O₂ saturation significantly (P<.001). The average CO₂ reduction achieved was 6.52±4.75mmHg (95% CI -7.7 to -5.3). The CO₂ values after pHV correlated significantly with seizure duration and O₂ values, with other electroencephalographic quality indices. In pHV sessions, compared with sessions performed according to hyperventilation standard practice, the average lengthening of the motor and electroencephalographic seizure was 3.86±14.62 and 4.73±13.95s, respectively. No differences were identified in other ictal quality parameters.

CONCLUSIONS

The proposed pHV manoeuvres significantly modify ventilation parameters. The hypocapnia and hyperoxia obtained by applying these manoeuvres lengthen the duration of seizures without worsening the quality of the electroencephalographic trace. The use of pHV is generalisable and might improve electroconvulsive therapy procedure without adding costs.

Emergency department procedural sedation and analgesia: A Canadian Community Effectiveness and Safety Study (ACCESS)

Objectives:

To determine the effectiveness and safety of procedural sedation and analgesia (PSA) in a Canadian community emergency department (ED) staffed primarily by family physicians and to assess the role of capnometry monitoring in PSA.

Methods:

One hundred and sixty (160) consecutive procedural sedation cases were reviewed from the ED of a rural hospital in Huntsville, Ont. The ED is mainly staffed by family physicians who have received in-house training in PSA. Safety and effectiveness measures were extrapolated from a standardized PSA form by a blinded research assistant.

Results:

The mean age of the patient population was 33.6 years (standard deviation = 23.6). Fifty-four percent of the patients were male, and 33% of the cases were pediatric. PSA medications included propofol (84%), fentanyl (51%) and midazolam (15%), and the procedural success rate was 95.6%. The adverse event (AE) rate was 18% and included apnea (10%), inadequate sedation (3%), bradycardia (2%), desaturation (1%), hypotension (1%) and bag-valve-mask use (1%). In those aged ≥65 years there was a greater incidence of apnea. There were no episodes of emesis and there were no intubations. A modified jaw thrust manoeuvre was used in 23% of the cases. In the 64% of cases where capnometry was used, there was no association between its use and any AE measures.

Conclusion:

Procedural sedation was safe and effective in our environment. Capnometry recording did not appear to alter outcomes, although the data are incomplete.

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.

The value of Integrated Pulmonary Index (IPI) monitoring during endoscopies in children

The Integrated Pulmonary Index (IPI) is an algorithm included in commercially available monitors that constitutes a representation of 4 parameters: EtCO2, RR, SpO2 and PR. The IPI index has been validated for adults and children older than 1 year of age. In this study we aimed to study the value of IPI monitoring during pediatric endoscopic procedures. Our data consisted of 124 measurements of 109 patients undergoing different procedures (upper endoscopy 84 patients, colonoscopy 6 patients, both 9 patients). The data was divided into 3 groups based on the drug type used: propofol only, 5 patients (group 1); propofol & midazolam, 89 patients (group 2); propofol, midazolam and Fentanyl, 15 patients (group 3). Patients in group 2 and 3 had significantly higher IPI levels than group 1. Significantly lower IPI values were found between ages 4-6 compared to 7-12 years old. High midazolam dose was associated with lower IPI levels during the procedure. No significant differences were found for propofol doses. Patients who had an anesthetist present had lower IPI levels during the procedure compared to those who did not. No differences were noted between the different procedures. IPI alerted all apnea episodes (58 events, IPI = 1) and hypoxia (26 events, IPI ≤ 3) episodes, whereas pulse oximetry captured only the hypoxia episodes (IPI sensitivity = 1, specificity 0.98, positive predictive value 0.95). Younger patient age, use of propofol alone, higher midazolam doses and presence of anesthetist are all associated with lower IPI levels.

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.

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.

Etomidate for short pediatric procedures in the emergency department

OBJECTIVE

This study aimed to prospectively determine the etomidate dose associated with adequate sedation and few significant respiratory events for procedures of short duration in children.

METHODS

This is a prospective cohort study in an urban pediatric emergency department of patients 4 to 18 years requiring sedation and analgesia for painful procedures of short duration. Patients received fentanyl 1 μg/kg followed by intravenously administered etomidate 0.1 to 0.2 mg/kg as a loading dose. An additional dose of etomidate 0.1 mg/kg was intravenously administered if needed. The level of sedation was determined by The Children's Hospital of Wisconsin Sedation Score. The primary outcome was to determine the etomidate dose associated with an adequate level of sedation and procedural completion.

RESULTS

Sixty patients were enrolled. The most frequent procedure was fracture reduction (50/60, 83.3%). Procedures were successfully completed for 59 (98.3%) of 60 patients. The initial dose of etomidate associated with adequate sedation was 0.2 mg/kg intravenously administered for 33 (66.7%) of 50 patients requiring fracture reduction and for 6 (60.0%) of 10 patients receiving a procedure other than fracture reduction. Respiratory depression was noted in 9 (16.4%) of 55 patients, and oxygen desaturation was noted in 23 (39.0%) of 59 patients. Of 58 patients, 21 (36.2%) experienced a respiratory adverse event requiring brief intervention including oxygen supplementation, stimulation, and/or airway repositioning. No patient experienced a significant adverse respiratory event, defined as positive pressure ventilation. Median time to discharge-ready was 21 minutes.

CONCLUSIONS

For short-duration painful emergency department procedures, etomidate 0.2 mg/kg intravenously administered after fentanyl was associated with effective sedation, successful procedural completion, and readily managed respiratory adverse events in children.

An evaluation of the Integrated Pulmonary Index (IPI) for the detection of respiratory events in sedated patients undergoing colonoscopy

The Integrated Pulmonary Index (IPI™) is a new decision making tool calculated from measured end tidal carbon dioxide (etCO(2)), respiratory rate (RR), oxygen saturation (SpO(2)) and pulse rate (PR) using a fuzzy logic model. The aim of this study was to compare prospectively IPI to respiratory adverse events in patients undergoing moderate sedation for colonoscopy. Following ethics committee approval and personal informed consent 51 adult patients undergoing elective colonoscopy were enrolled. Patients received routine care by the endoscopy staff that were blinded to IPI, etCO(2), and RR; whilst a trained senior anesthesiologist observer, not involved in the procedure, collected this data. 'Requires attention' respiratory adverse events (at least 1 min of SpO(2) ≤ 92 % and/or RR ≤ 8 and or 20 % decrease in etCO(2)) and 'requires intervention' respiratory adverse events (at least 1 min of SpO(2) ≤ 85 % and/or RR = 0) were documented by the observer. There were no differences in etCO(2), RR, SpO(2) and PR between 5778 IPI readings ranging from 1 to 10. Low (1-3), medium (4-6) and high (7-10) IPI groups did not differ in RR, SpO(2) and PR, but etCO(2) was higher in the high IPI group (p = 0.0185). Among requires attention events (n = 113) the IPI was high (7-10) in 53.1 %, intermediate (4-6) in 32.7 %, or low (1-3) in 14.2 %. The presented data demonstrate limited agreement between respiratory physiological parameters and the IPI. Further IPI evaluation and validation is indicated mainly for events requiring immediate intervention and in different patient populations including obese patients.

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.

Capnography and the bispectral index-their role in pediatric sedation: a brief review

Sedation in children is increasingly emerging as a minimally invasive technique that may be associated with local anaesthesia or diagnostic and therapeutic procedures which do not necessarily require general anaesthesia. Standard monitoring requirements are not sufficient to ensure an effective control of pulmonary ventilation and deep sedation. Capnography in pediatric sedation assesses the effect of different drugs on the occurrence of respiratory failure and records early indicators of respiratory impairment. The Bispectral index (BIS) allows the reduction of dose requirements of anaesthetic drugs, the reduction in the time to extubation and eye opening, and the reduction in the time to discharge. In the field of pediatric sedation, capnography should be recommended to prevent respiratory complications, particularly in spontaneous ventilation. The use of the BIS index, however, needs further investigation due to a lack of evidence, especially in infants. In this paper, we will investigate the role of capnography and the BIS index in improving monitoring standards in pediatric sedation.

General anaesthesia for external electrical cardioversion of atrial fibrillation: experience of an exclusively cardiological procedural management

AIMS

External electrical cardioversion (EC) usually requires brief general anaesthesia involving anaesthetists. The aim of this study was to evaluate the feasibility and safety of inducing anaesthesia for EC of atrial fibrillation (AF) exclusively by the cardiologic team with anaesthetists on-hand.

METHODS AND RESULTS

A retrospective analysis of 624 elective EC, over a 6-year period, was made. No patients were excluded due to the severity of pathology or comorbidities. The protocol of the intravenous anaesthesia was 5 mg bolus of midazolam and subsequent increasing doses of propofol starting from 20 mg to achieve the desired sedation level. After delivering DC shock, a direct observation period followed in order to assess the post-sedation recovery and to detect the procedure-related complications. Electrical cardioversion was effective in 98.9% of the cases. General anaesthesia was effective in 100% of cases with a dosage of propofol, ranging between 20 mg to a maximum of 80 mg, after 5 mg of midazolam was administered. All patients generally showed a fast recovery waking up in a few minutes. The anaesthesiology team was never called for assistance. All the procedures were carried out by the cardiologic team as planned. No thrombo-embolic and allergic complications were observed. Arrhythmic complications were uncommon and essentially bradyarrhythmias.

CONCLUSION

A general anaesthesia for outpatient EC of AF can be safely handled by a cardiologist having adequate experience with anaesthetical agents. Moreover, the association of midazolam and a very small dosage of propofol, given their synergic action, is effective and safe in inducing anaesthesia. Arrhythmic complications are rare and limited to bradyarrhythmias.

Randomized clinical trial of propofol versus ketamine for procedural sedation in the emergency department

OBJECTIVES

The objective was to compare the occurrence of respiratory depression, adverse events, and recovery duration of propofol versus ketamine for use in procedural sedation in the emergency department (ED).

METHODS

This was a randomized nonblinded prospective clinical trial of adult patients undergoing procedural sedation for painful procedures in the ED. Patients with pain before the procedure were treated with intravenous (IV) morphine sulfate until their pain was adequately treated at least 20 minutes before starting the procedure. Patients were randomized to receive either propofol 1 mg/kg IV followed by 0.5 mg/kg every 3 minutes as needed or ketamine 1.0 mg/kg IV followed by 0.5 mg/kg every 3 minutes as needed. Doses, vital signs, nasal end-tidal CO(2) (ETCO(2)), and pulse oximetry were recorded. Subclinical respiratory depression was defined as a change in ETCO(2) of >10 mm Hg, an oxygen saturation of <92% at any time, or an absent ETCO(2) waveform at any time. Clinical interventions related to respiratory depression were noted during the procedure, including the addition of or increase in the flow rate of supplemental oxygen, the use of a bag-valve mask apparatus, airway repositioning, or stimulation to induce breathing. After the procedure, patients were asked if they experienced pain during the procedure and had recall of the procedure. Physicians were asked to describe any adverse events or the occurrence of recovery agitation.

RESULTS

One-hundred patients were enrolled; 97 underwent sedation and were included in the analysis. Fifty patients received propofol and 47 received ketamine. Subclinical respiratory depression was seen in 20 of 50 patients in the propofol group and 30 of 47 patients in the ketamine group (p = 0.019, effect size 22.8%; 95% CI = 4.0% to 43.6%). Clinical interventions related to respiratory depression were used in 26 of 50 propofol patients and 19 of 47 ketamine patients (p = 0.253, effect size = -13.7%; 95% CI = -33.8% to 6.4%). The median times of the procedures were 11 minutes (range = 4 to 33 minutes) for the ketamine group versus 10 minutes (range = 5 to 33 minutes) for the propofol group (p = 0.256). The median time to return to baseline mental status after the procedure was completed was 14 minutes (range = 2 to 47 minutes) for the ketamine group and 5 minutes (range = 1 to 32 minutes) for the propofol group (p < 0.001). Pain during the procedure was reported by 3 of 50 patients in the propofol group and 1 of 47 patients in the ketamine group (effect size = -3.9%, 95% confidence interval [CI] = -11.9 to 4.1). Recall of some part of the procedure was reported by 4 of 50 patients in the propofol group and 6 of 47 patients in the ketamine group (effect size = 4.8%, 95% CI = -7.6% to 17.1%). Forty-eight of 50 procedures were successful in the propofol group and 43 of 47 in the ketamine group (p = 0.357, effect size = 0.3%; 95% CI = -7.8% to 8.4%). Recovery agitation was reported in 4 of 50 in the propofol group and 17 of 47 in the ketamine group (effect size = 28.2%, 95% CI = 12.4% to 43.9%).

CONCLUSIONS

This study detected a higher rate of subclinical respiratory depression in patients in the ketamine group than the propofol group. There was no difference in the rate of clinical interventions related to respiratory depression, pain, or recall of the procedure between the groups. Recovery agitation was seen more frequently in patients receiving ketamine than in those receiving propofol. The time to regain baseline mental status was longer in the ketamine group than the propofol group. This study suggests that the use of either ketamine or propofol is safe and effective for procedural sedation in the ED.

Paramedic Rapid Sequence Intubation for Severe Traumatic Brain Injury: Perspectives from an Expert Panel

Although early intubation has become standard practice in the prehospital management of severe traumatic brain injury (TBI), many patients cannot be intubated without neuromuscular blockade. Several emergency medical services (EMS) systems have implemented paramedic rapid sequence intubation (RSI) protocols, with published reports documenting apparently conflicting outcomes effects. In response, the Brain Trauma Foundation assembled a panel of experts to interpret the existing literature regarding paramedic RSI for severe TBI and offer guidance for EMS systems considering adding this skill to the paramedic scope of practice. The interpretation of this panel can be summarized as follows: (1) the existing literature regarding paramedic RSI is inconclusive, and apparent differences in outcome can be explained by use of different methodologies and variability in comparison groups; (2) the use of Glasgow Coma Scale score alone to identify TBI patients requiring RSI is limited, with additional research needed to refine our screening criteria; (3) suboptimal RSI technique as well as subsequent hyperventilation may account for some of the mortality increase reported with the procedure; (4) initial and ongoing training as well as experience with RSI appear to affect performance; and (5) the success of a paramedic RSI program is dependent on particular EMS and trauma system characteristics.

Assessment of end-tidal carbon dioxide during pediatric and adult sedation for endoscopic procedures

BACKGROUND

Pulse oximetry has become the standard of care during endoscopic procedures, despite the fact that significant alveolar hypoventilation may be undetected.

OBJECTIVE

To study the value of end-tidal carbon dioxide (EtCO(2)) measurement during pediatric and adult endoscopic procedures with the patient under general anesthesia (GA) and conscious sedation (CS).

DESIGN AND SETTINGS

Oridion Microcap hand-held capnography by using Smart Bite Bloc with oxygen (O(2)) delivery were used for the procedures. Microstream nondispersive infrared (IR) spectroscopy is used to measure the concentration of molecules that absorb IR light in CO(2) exhaled by the subject. For each patient, we defined an "event" based on a combination of a >or=20% change (increase or decrease) in EtCO(2), with at least one of the following: O(2) saturation (SPO(2)) <or=90%, a >or=20% change of pulse rate or respiratory rate.

PATIENTS

We studied 57 patients, with an age range of 4 to 62 years. Nineteen patients (33.3%) had CS and 38 (66.6%) had GA.

RESULTS

Twenty patients had no events, 32 had 1 event, and 5 patients had 2 events. The highest observed frequency of an event was noted during upper endoscopy under GA (0.35), followed by upper endoscopy under CS (0.32). Fitted univariate logistic regression models indicated that higher variability in EtCO(2) is associated with a higher probability for an event (P < .0001) and that an increase in age is associated with a lower probability for an event (P < .0001). Significant differences in the frequencies of SPO(2) events were related to the type of procedure (P = .0002; highest estimated probability for upper endoscopy) and GA (P < .0001). Similar conclusions were obtained based on the fitted multivariate model.

CONCLUSIONS

EtCO(2) contributes significantly to the prediction of events during endoscopy. A lower mean of EtCO(2), higher variability of EtCO(2), younger age, GA, and upper endoscopy increase the probability of an event.

The correlation and level of agreement between end-tidal and blood gas pCO2 in children with respiratory distress: a retrospective analysis

BACKGROUND

To investigate the correlation and level of agreement between end-tidal carbon dioxide (EtCO2) and blood gas pCO2 in non-intubated children with moderate to severe respiratory distress.

METHODS

Retrospective study of patients admitted to an intermediate care unit (InCU) at a tertiary care center over a 20-month period with moderate to severe respiratory distress secondary to asthma, bronchiolitis, or pneumonia. Patients with venous pCO2 (vpCO2) and EtCO2 measurements within 10 minutes of each other were eligible for inclusion. Patients with cardiac disease, chronic pulmonary disease, poor tissue perfusion, or metabolic abnormalities were excluded.

RESULTS

Eighty EtCO2-vpCO2 paired values were available from 62 patients. The mean +/- SD for EtCO2 and vpCO2 was 35.7 +/- 10.1 mmHg and 39.4 +/- 10.9 mmHg respectively. EtCO2 and vpCO2 values were highly correlated (r = 0.90, p < 0.0001). The correlations for asthma, bronchiolitis and pneumonia were 0.74 (p < 0.0001), 0.83 (p = 0.0002) and 0.98 (p < 0.0001) respectively. The mean bias +/- SD between EtCO2 and vpCO2 was -3.68 +/- 4.70 mmHg. The 95% level of agreement ranged from -12.88 to +5.53 mmHg. EtCO2 was found to be more accurate when vpCO2 was 35 mmHg or lower.

CONCLUSION

EtCO2 is correlated highly with vpCO2 in non-intubated pediatric patients with moderate to severe respiratory distress across respiratory illnesses. Although the level of agreement between the two methods precludes the overall replacement of blood gas evaluation, EtCO2 monitoring remains a useful, continuous, non-invasive measure in the management of non-intubated children with moderate to severe respiratory distress.

Predictors of airway and respiratory adverse events with ketamine sedation in the emergency department: an individual-patient data meta-analysis of 8,282 children

STUDY OBJECTIVE

Although ketamine is one of the most commonly used sedatives to facilitate painful procedures for children in the emergency department (ED), existing studies have not been large enough to identify clinical factors that are predictive of uncommon airway and respiratory adverse events.

METHODS

We pooled individual-patient data from 32 ED studies and performed multiple logistic regressions to determine which clinical variables would predict airway and respiratory adverse events.

RESULTS

In 8,282 pediatric ketamine sedations, the overall incidence of airway and respiratory adverse events was 3.9%, with the following significant independent predictors: younger than 2 years (odds ratio [OR] 2.00; 95% confidence interval [CI] 1.47 to 2.72), aged 13 years or older (OR 2.72; 95% CI 1.97 to 3.75), high intravenous dosing (initial dose > or =2.5 mg/kg or total dose > or =5.0 mg/kg; OR 2.18; 95% CI 1.59 to 2.99), coadministered anticholinergic (OR 1.82; 95% CI 1.36 to 2.42), and coadministered benzodiazepine (OR 1.39; 95% CI 1.08 to 1.78). Variables without independent association included oropharyngeal procedures, underlying physical illness (American Society of Anesthesiologists class >or = 3), and the choice of intravenous versus intramuscular route.

CONCLUSION

Risk factors that predict ketamine-associated airway and respiratory adverse events are high intravenous doses, administration to children younger than 2 years or aged 13 years or older, and the use of coadministered anticholinergics or benzodiazepines.

Quantitative end-tidal carbon dioxide in acute exacerbations of asthma

OBJECTIVE

To examine quantitative end-tidal carbon dioxide (ETCO(2)) in children with acute exacerbations of asthma. We hypothesize that quantitative ETCO(2) will be lower in children during an acute exacerbation of asthma and will correlate with the severity of the exacerbation. We also hypothesize that ETCO(2) can be successfully performed in all groups in the setting of a pediatric emergency department.

STUDY DESIGN

Patients with acute exacerbation of asthma (n = 86) and control subjects without respiratory or metabolic disturbances (n = 88) were prospectively enrolled in a pediatric emergency department. A physical examination, vital signs, and ETCO(2) measurements were performed on arrival and, in the patients with asthma, after each bronchodilator treatment.

RESULTS

ETCO(2) was measured successfully in 97% of enrolled children. After adjusting for respiratory rate, ETCO(2) was significantly lower in patients with acute exacerbation of asthma than in control subjects (P < .001). ETCO(2) measured after the first and after the final bronchodilator treatment were significantly associated with the number of bronchodilator treatments received and with hospital admission (P < or = .002).

CONCLUSIONS

ETCO(2) can be successfully measured in all children and is significantly lower in children with acute exacerbations of asthma compared with healthy control subjects. Quantitative ETCO(2) may be an objective, noninvasive, and effort-independent way to assess the severity of asthma.

Current utilization of continuous end-tidal carbon dioxide monitoring in pediatric emergency departments

OBJECTIVE

End-tidal carbon dioxide (ETCO2) monitoring has numerous clinical applications in the emergency setting. This study was designed to explore the current availability and utilization patterns for continuous ETCO2 monitoring in pediatric emergency departments.

METHODS

A Web-based survey was distributed to directors of all accredited pediatric emergency medicine fellowship programs in the United States and Canada.

RESULTS

Eighty-one percent of directors completed this survey. Eighty-eight percent had access to ETCO2 monitoring for intubated patients and 53% for nonintubated patients. Seventy-nine percent of respondents used ETCO2 monitoring "always" or "often" for endotracheal tube confirmation. Only 20% of respondents used ETCO2 monitoring "always" or "often" for moderate sedation, 16% for trauma, and 6% for acid-base disturbances. One hundred percent of respondents who used ETCO2 monitoring felt that it was easy to use. The most common reason for not using ETCO2 monitoring was lack of equipment (65%).

CONCLUSIONS

ETCO2 monitoring is widely available, yet underutilized, for spontaneously breathing patients in pediatric emergency departments.

Procedural sedation for insertion of central venous catheters in children: comparison of midazolam/fentanyl with midazolam/ketamine

BACKGROUND

There is a lack of studies evaluating procedural sedation for insertion of central venous catheters (CVC) in pediatric patients in emergency departments or pediatric intensive care units (PICU). This study was designed to evaluate whether there is a difference in the total sedation time for CVC insertion in nonintubated children receiving two sedation regimens.

METHODS

Patients were prospectively randomized to receive either midazolam/fentanyl (M/F) or midazolam/ketamine (M/K) i.v. The Children's Hospital of Wiscosin Sedation Scale was used to score the sedation level.

RESULTS

Fifty seven patients were studied (28 M/F and 29 M/K). Group M/F received midazolam (0.24 +/- 0.11 mg.kg(-1)) and fentanyl (1.68 +/- 0.83 microg.kg(-1)) and group M/K received midazolam (0.26 +/- 0.09 mg.kg(-1)) and ketamine (1.40 +/- 0.72 mg.kg(-1)). The groups were similar in age, weight, risk classification time and sedation level. Median total sedation times for M/F and M/K were 97 vs 105 min, respectively (P = 0.67). Minor complications occurred in 3.5% (M/F) vs 20.7% (M/K) (P = 0.03). M/F promoted a greater reduction in respiratory rate (P = 0.005).

CONCLUSIONS

In this study of nonventilated children in PICU undergoing central line placement, M/F and M/K provided a clinically comparable total sedation time. However, the M/K sedation regimen was associated with a higher rate of minor complications. A longer period of study is required to assess the efficacy and safety of these sedative agents for PICU procedures in nonintubated children.

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.

Predicting the need for hospitalization in acute childhood asthma using end-tidal capnography

OBJECTIVE

To explore the utility of end-tidal capnography for predicting hospitalization in acute childhood asthma.

DESIGN, SETTING, AND PARTICIPANTS

A prospective cohort study of a convenience sample of children 5 to 17 years of age presenting to a pediatric emergency department with an acute asthma exacerbation. Capnography was performed at baseline. The length of the plateau portion of the baseline capnograph waveform was measured in millimeters and divided by the respiratory rate at the time of the measurement to create a ratio. The sensitivity and specificity of the baseline capnography ratio for predicting hospitalization were assessed.

MAIN OUTCOME MEASURES

Hospitalization versus discharge from the pediatric emergency department.

RESULTS

Thirty-seven patients were enrolled. The hospitalized (n = 12) and discharged (n = 25) groups did not differ in terms of any demographic or baseline characteristics except for pulmonary score and the median baseline capnography ratio. The median ratio was 0.15. Ten (83.3%) of 12 of patients who were hospitalized had a baseline ratio less than 0.15 compared with 8 (32%) of 25 of patients who were discharged from pediatric emergency department (P < 0.05). Controlling for baseline asthma severity, the odds of being hospitalized if the baseline capnography ratio was less than 0.15 were 18.77 (95% confidence interval, 1.91-184.69).

CONCLUSION

This pilot study suggests that baseline capnography may be useful as an objective effort-independent tool for identifying children with an asthma exacerbation who are at risk for hospitalization.

Sedation in the emergency department

Pediatric ED patients now have a wide variety of options to help relieve the pain and apprehension associated with an ED visit. Safe and effective management of these children has become a priority in properly staffed and equipped EDs throughout the country.

Pediatric pain management in the emergency department

Over the past 25 years, pediatric emergency medicine research and literature have progressively augmented our knowledge of safe and effective pediatric pain management strategies. Yet there is still much more we need to do to understand the painful experiences of children, and to develop optimal safe ways of addressing their needs within the context of a busy pediatric emergency department (ED). In this article, the authors review the history of ED pediatric pain management and sedation, discuss special considerations in pediatric pain assessment and management, review various pharmacologic and nonpharmacologic methods of alleviating pain and anxiety, and present ideas to improve the culture of the pediatric ED, so that it can achieve the goal of becoming pain-free.

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.

Cardioversion and the use of sedation

Nurse led cardioversion services have achieved significant reductions in both cost and waiting time. However, the question of safety of the procedure raises several areas of concern.

Capnography Accurately Detects Apnea During Monitored Anesthesia Care

Apnea and airway obstruction are common during monitored anesthesia care (MAC). Because their early detection is essential, we sought to measure the efficacy of capnography as an indicator of apnea during MAC at a variety of oxygen flow rates compared with thoracic impedance. Anesthesia care providers using standard American Society of Anesthesiologists monitors were blinded to capnography and thoracic impedance monitoring. Ten (26%) of the 39 patients studied developed 20 s of apnea; none was detected by the anesthesia provider, but all were detected by capnography and impedance monitoring. There was no difference in detection rates between the two methods. Higher oxygen flow rates decreased the amplitude of the capnograph but did not interfere with apnea detection. This pilot study revealed that apnea of at least 20 s in duration may occur in every fourth patient undergoing MAC. Although these episodes were undetected by the anesthesia provider, they were reliably detected by both capnography and respiratory plethysmography. Monitoring of nasal end-tidal CO(2) is an important way to improve safety in patients undergoing MAC.

The value of capnography during sedation or sedation/analgesia in pediatric minor procedures

OBJECTIVE

To measure changes in end-tidal carbon dioxide levels (ETco2) with different sedation/analgesia (midazolam, ketamine, ketamine plus midazolam, midazolam plus fentanyl, and propofol) during pediatric minor surgical procedures and to determine whether there were significant increases in ETco2 with different drugs.

METHODS

We conducted a prospective, randomized, clinical trial of 126 children who needed sedation/analgesia in pediatric intensive care unit in a university hospital. Patients were randomly assigned to 1 of 5 treatment groups. Group K received only intravenous (IV) ketamine 1 mg/kg; group M, IV midazolam 0.15 mg/kg; group KM, IV ketamine 1 mg/kg plus IV midazolam 0.1 mg/kg; group MF, IV midazolam 0.1 mg/kg plus IV fentanyl 2 microg/kg; and group P, IV propofol 2 mg/kg. Side stream, nasal cannula ETco2 tracings were recorded on a capnograph (Capnostat, Marquette). Recordings began prior to the administration of medications and continued throughout the procedure until the patient was fully awake. The primary outcome variable was the difference between peak ETco2 before and during sedation/analgesia. This value was determined by scanning the records for the peak ETco2 averaged over 5 breaths before and after the administration of medications.

RESULTS

There was neither any statistical difference between presedation/analgesia and postsedation/analgesia ETco2 levels in the 5 groups (P > 0.05) nor any difference in the first 3 groups between presedation/analgesia, sedation/analgesia, and postsedation/analgesia (K, M, and KM) (P > 0.05). In the midazolam plus fentanyl and propofol groups, mean ETco2 during sedation/analgesia was higher than the mean ETco2 during presedation/analgesia and postsedation/analgesia (P < 0.05). Twenty-one patients (16, 6%) had respiratory depression [hypercarbia (ETco2 > 50 mm Hg) or hypoxia (oxygen saturation > 90% for over 1 minute)], 21 patients (16, 6%) had hypercarbia, and 4 patients (3.2%) had both hypoxia and hypercarbia. One of 4 patients was in the MF group, and 3 were in the P group. Two subjects (8%) in the KM group, 7 (28%) in the MF group, and 13 (52%) in the P group had hypercarbia.

CONCLUSIONS

This study demonstrated that propofol and midazolam-fentanyl produced a higher incidence of respiratory depression and higher mean ETco2 during sedation/analgesia than presedation and postsedation/analgesia. Capnography can serve as a useful monitoring tool in the evaluation of ventilation during sedation or sedation/analgesia in clinically stable children.

Effects of IV Pentobarbital With and Without Fentanyl on End-Tidal Carbon Dioxide Levels During Deep Sedation of Pediatric Patients Undergoing MRI

OBJECTIVE

IV pentobarbital is used in radiology departments for sedating pediatric patients undergoing diagnostic imaging. To our knowledge, no published studies have documented end-tidal carbon dioxide levels during sedation with IV pentobarbital. The purpose of this prospective study was to determine the effects of different doses of IV pentobarbital with or without fentanyl on end-tidal carbon dioxide levels during deep sedation of pediatric patients undergoing MRI.

SUBJECTS AND METHODS

One hundred sixty-five patients (70 girls, 95 boys) having a mean age of 3.4 years received IV pentobarbital sedation with or without fentanyl for undergoing MRI from January through March 2002. Each child was sedated with 2-6 mg/kg of body weight of IV pentobarbital and an additional 1-3 micro g/kg of fentanyl if needed. After the administration of sedation, a 28-ft (8.5 m) nasal cannula with capnography capability was applied to each patient, and capnogram tracings and values were recorded every 5 min.

RESULTS

Mean values of end-tidal carbon dioxide were between 37 and 42 mm Hg during 60 min of sedation for both groups. When IV pentobarbital was used alone, no significant difference was seen between patients who received 3-5 mg of pentobarbital and those who received more than 5 mg (p = 0.97, F test).

CONCLUSION

End-tidal carbon dioxide levels remain within normal clinical range during sedation with IV pentobarbital with or without fentanyl. Our sedation protocol produced no significant deviations from normal respiratory parameters.