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ED procedural sedation of elderly patients: is it safe?
American Journal of Emergency Medicine (2011) 29, 541–544
www.elsevier.com/locate/ajem
Original Contribution
ED procedural sedation of elderly patients: is it safe?☆ Christopher S. Weaver MD a,⁎, Kevin M. Terrell DO, MS a,b,c , Robert Bassett DO a , William Swiler DO a , Beth Sandford RN a , Sara Avery RN a , Anthony J. Perkins MS b a
Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN, USA Indiana University Center for Aging Research, Indiana University School of Medicine, Indianapolis, IN, USA c Regenstrief Institute, Indiana University School of Medicine, Indianapolis, IN, USA b
Received 9 September 2009; revised 4 November 2009; accepted 15 December 2009
Abstract Objective: Emergency physicians routinely perform emergency department procedural sedation (EDPS), and its safety is well established. We are unaware of any published reports directly evaluating the safety of EDPS in older patients (≥65 years old). Many EDPS experts consider seniors to be at higher risk. The objective was to evaluate the complication rate of EDPS in elderly adults. Methods: This was a prospective, observational study of EDPS patients at least 65 years old, as compared with patients aged 18 to 49 and 50 to 64 years. Physicians were blind to the objectives of this research. The study protocol required an ED nurse trained in data collection to be present to record vital signs and assess for any prospectively defined complications. We used American Society of Anesthesiologists (ASA) physical status classification for systemic disease to evaluate and account for the comorbidities of patients. We used the Fisher exact test for the difference in proportions across age groups and analysis of variance for the differences in dosing across age and ASA categories. Results: During the 4-year study, we enrolled 50 patients at least 65 years old, 149 patients aged 50 to 64 years, and 665 patients aged 18 to 49 years. Adverse event rates were 8%, 5.4%, and 5.2%, respectively (P = .563). The at least 65 years age group represented a greater percentage of those with higher ASA scores (P b .001). The average total sedative dose in the at least 65 years group was significantly lower than the comparisons (P b .001). Conclusions: This study demonstrated no statistically significant difference in complication rate for patients 65 years or older. There was a significant decrease in mean sedation dosing with increased age and ASA score. © 2011 Elsevier Inc. All rights reserved.
1. Introduction In emergency departments (EDs), sedatives and/or analgesics are frequently administered during brief, painful ☆
Presented: Poster presentation at 2009 SAEM Annual Meeting, May 2009, New Orleans, LA. ⁎ Corresponding author. Wishard Memorial Hospital, Indianapolis, IN 46202, USA. Tel.: +1 317 630 7276; fax: +1 317 6564216. E-mail address: [email protected] (C.S. Weaver). 0735-6757/$ – see front matter © 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.ajem.2009.12.017
procedures (eg, fracture or dislocation reduction, abscess incision and drainage, wound care). This process is termed emergency department procedural sedation (EDPS), and various individual sedatives or a combination of sedatives may be used [1-7]. When performed correctly, EDPS is a safe method to minimize pain and awareness of uncomfortable procedures [1-7]. The reported rates of adverse events in adults have ranged from 5% to 20%. Although EDPS has been shown to be safe for adults in general, we are unaware of any published
542 reports that were specifically designed to evaluate the safety of EDPS in older patients. Emergency departments are major providers for older adults. Patients 65 years and older made more than 16.7 million visits to EDs (or 14.5% of all visits) in 2005 [8]. Many EDPS experts consider elderly patients to be at higher risk for adverse events during EDPS [9]. The objective of this research was to evaluate the complication rate of EDPS in older adults as compared with younger adults. In addition to determining adverse event rates, we sought to investigate any differences between older and younger adult patients with respect to success of procedure, medication selection, and medication dosing.
2. Materials and methods 2.1. Study design This was a prospective, observational study of EDPS in older adults. The Indiana University School of Medicine Institutional Review Board approved the study before data collection.
2.2. Study population and setting The study population included all older ED patients (defined as those 65 years or older) who received procedural sedation between January 1, 2004, and January 21, 2008. Procedural sedation was defined as parenteral administration of a medication with sedating properties (with or without an analgesic) to facilitate a procedure in the ED. We compared the study population to all patients aged 18 to 49 and 50 to 64 years who underwent EDPS during the study period. This study was conducted in the ED of an urban, academic, level I trauma center with a volume of approximately 100 000 annual visits.
2.3. Procedures and measurements Standard monitoring and procedures, as required by the hospital's EDPS protocol, were followed. In addition to an emergency physician, the EDPS protocol requires an emergency nurse assistant to be in the room to monitor the vital signs, pulse oximetry, and possible complications and to administer the ordered medications. Data for this research were collected by the emergency nurses. Before data collection, we defined each data point and trained the nurses collecting the data. The trained emergency nurses assessed and recorded vital signs, ventilation, airway evaluation (eg, snoring, partial obstruction, obstruction, signs of aspiration), pulse oximetry, and complications every 5 minutes and nadir. The nurses also documented all administered medications and doses.
C.S. Weaver et al. All emergency physicians, other than the investigators, were blind to the objectives of this research. The emergency medicine attending physician or the emergency medicine resident (under the direct supervision of the attending physician) conducted the procedural sedation in their usual fashion. The emergency physician was responsible for the preprocedure assessment, sedation plan, dosing of medication, completion of the procedure, and standard monitoring of the patient. The frequency and incremental dosing of medication were left to the discretion of the individual treating physician. An analgesic was considered sedation analgesic if it was given less than 5 minutes before the first dose of sedative medication. Complications were prospectively defined as apnea, postprocedure nausea/vomiting, laryngospasm, hypotension, heart rate less than 50 beats per minute or rhythm disturbance, rescue maneuver (ie, head repositioning, jaw thrust, use of oral airway, increase in oxygen administration, increase in stimulation, unplanned use of reversal agents), hypoxemia, aspiration, bag valve mask ventilation, intubation, any blood pressure or heart rate interventions, hospital admission, and death. Apnea was defined as no ventilation effort with no obvious airway obstruction. Systolic blood pressure less than 90 mm Hg was considered hypotension. Bradycardia was defined as a heart rate less than 50 unless the patient had preexisting bradycardia. Any patient with an oxygen saturation less than 90% for more than 10 seconds was considered to be hypoxemic. Aspiration was defined as emesis or reflux from mouth or nose during sedation, coughing or gagging during sedation and subsequent prolonged decrease in oxygen saturation by 5% from baseline, chest x-ray evidence of aspiration, or evidence of aspiration including respiratory complaints, prolonged unexplained cough, or dyspnea. We used the American Society of Anesthesiologists (ASA) physical status classification for systemic disease [10] to evaluate and account for the comorbidities of patients when comparing complications. We enrolled patients in classes I (normal healthy patient), II (mild systemic disease), III (severe systemic disease), and IV (severe systemic disease that is a constant threat to life), but none in class V (moribund patient not expected to live another 24 hours) or VI (braindead patient whose organs are being removed for donor purposes). To compare narcotic dosing, we used a previously published conversion table that equates intravenous morphine 5 mg, intravenous hydromorphone 1 mg, and intravenous fentanyl 100 μg [11].
2.4. Data analysis We used Fisher exact test to compare the proportion of adverse events and unsuccessful procedures across age and ASA categories. χ2 tests were used to compare medication and procedure categories across the 3 age groups. We used 1-way analysis of variance to test for differences in sedation dosage across age groups. All analyses were performed using SAS V9.0 (SAS, Cary, NC).
Elderly procedural sedation
543
3. Results During the 4-year study period, 868 adult patients were enrolled. Age was not recorded for 4 subjects who were excluded from the analysis. Five hundred twenty-nine (61.43%) were male. Fifty (5.8% of all EDPS patients) elderly study subjects were included and compared with 149 (17.2%) in the 50 to 64 age group and 665 (77.0%) in the 18 to 49 group. Four hundred eleven (49%) subjects were white, 337 (39.5%) were black, 85 (10.0%) were Hispanic, and 21 (2.3%) were of other racial/ethnic heritage. Table 1 demonstrates the adverse event rate and procedure success rate across age groups. There was no statistically significant difference (P = .563) in adverse events across age groups, although the oldest age group had the highest adverse event rate. There was a marginally significant difference (P = .086) across age groups when looking at hypotension only. The difference is such that elderly patients had the highest hypotension rate. There were no statistically significant differences across age group for Table 1 Association of age with demographic and clinical characteristics (N = 864) 18-49 y 50-64 y 65+ y P (n = 665) (n = 149) (n = 50) value Adverse event and procedure success % Adverse event % Hypotension % Oxygen saturation % Unsuccessful procedure % Adverse event or unsuccessful procedure ASA score %1 %2 %3 %4 Procedure % Chest tube placement % Dislocation reduction % Hernia reduction % Incision and drainage % Lumbar puncture % Miscellaneous Medications given % Propofol alone % Propofol + narcotic % Versed + narcotic % Other combinations
5.2 2.1 2.6 3.6
5.4 0.7 4.7 3.4
8.0 6.0 2.0 4.0
.563 .086 .346 .943
8.6
8.8
12.0
.676
b.001 43.3 42.2 12.7 1.8
20.1 32.9 40.3 6.7
6.0 32.0 36.0 26.0
4.5
2.0
4.0
64.2
62.4
68.0
2.1 17.8
4.0 14.1
6.0 8.0
2.4 8.9
6.0 11.4
4.0 10.0
49.7 38.8 8.4 3.2
46.6 36.5 8.8 8.1
57.1 38.8 0.0 4.1
.119
.056
oxygen saturation or for an unsuccessful procedure. The combination of an adverse event or unsuccessful procedure did not differ significantly across age. Subjects' ASA scores significantly rose in each increasing age group. There was no difference in the procedures performed across age group, with dislocation reduction accounting for more than 60% of all procedures in each age group. Propofol was the most frequently used sedation agent in each age group. There was a significant difference in the dose of medication given between the age groups, with the older age groups getting lower doses. Among patients in which propofol was the sole agent, the mean dose was 158 mg in the 18 to 49 age group, 124 mg in the 50 to 64 age group, and 106 mg in the at least 65 age group (P b .001). Among subjects who received both narcotic pain medication and propofol, the mean doses of propofol for each group were 172, 133, and 100 mg for age groups 18 to 49, 50 to 64, and at least 65 years, respectively (P = .002). The mean dose of narcotic in this group was not significantly different. With dosing in morphine equivalents, the age groups received 12, 10, and 9 mg, respectively (P = .707). There was no significant difference in adverse events across ASA scores (P = .827). However, the rate of unsuccessful procedures (3.2% for ASA I, 2.3% for ASA II, 5.0% for ASA III, and 11.4% for ASA IV) differed significantly across ASA score (P = .042). There was no significant difference in adverse event rates across procedure type, but there was a significant difference in procedure success across the different procedures performed (P = .001). Hernia reduction resulted in 21% unsuccessful procedures, lumbar puncture was unsuccessful in 11%, whereas all other procedures' unsuccessful rate was less than 5%.
4. Discussion Our prospective, observational study of 868 EDPS patients included 50 patients aged at least 65 years. As we compared these elderly patients with those younger, we found no significant difference in adverse events or procedure success rates. The choice of medication was also similar between the age groups. However, the dose of the sedative agent did decrease as age increased. These findings raise several questions: Are the physicians making a conscious decision to decrease the dose they are giving because the patients are older and therefore protecting against complications in this population thought to be at a higher risk? Or are the patients reaching the adequate level of sedation with a lower dose? Are the patients achieving the same sedation level as those younger? In Miner and Burton's [9] “Clinical practice advisory” on propofol sedation, they reported that lower doses of propofol are required to achieve a defined end point in patients older than 55 years. In addition, they state that the hypotensive effects of propofol are more pronounced with advanced age
544 and that evidence supports an advanced age predisposition to airway and respiratory adverse events [9]. The authors recommend future studies to assess potential differences based on age. Our study evaluated different age groups for adverse events such as hypotension and airway complications. As described above, we did not find a significant difference between the groups in these parameters but did find that lower doses of propofol were used. In a study evaluating the use of propofol for procedural sedation, the average age of patients experiencing oxygen desaturation was higher than those without this complication [1]. Burton et al [1] completed a prospective, descriptive series but were assessing the frequency of respiratory and cardiovascular events in all patients receiving propofol sedation at 3 study sites. They found that the mean age of those who dropped to a SpO2 less than 90% was 51 years as compared with 40 years in those who did not. Increased age was also associated with the need for bag valve mask ventilation (52 years in those with and 41 years in those without). Although Burton and colleagues reported the mean age and range of ages from each institution, they did not report the number of patients older than 65 years and the number of sedation events in that population. In our comparison of patients at least 65 years old to those younger, we did not find a significant difference in respiratory adverse events such as decreased oxygen saturation; and there were no incidents of bag valve mask ventilation in our study. In another study evaluating propofol sedation, Kazama et al [12] found the hypotensive effect of propofol to be more pronounced in those with advanced age. The authors evaluated the effects of propofol demonstrated by electroencephalogram or blood pressure changes compared between elderly and young or middle-aged patients. They performed a controlled infusion to attain specific plasma propofol concentrations. All of their patients were ASA I or II. The systolic blood pressure decreased as propofol plasma concentration increased, with this occurring significantly more readily in those 70 to 85 years of age as compared with those younger. In our study, 6% of those at least 65 years old developed a drop in systolic blood pressure to less than 90 mm Hg as compared with 2.1% and 0.7% in the younger groups.
5. Limitations The interpretation of this study is subject to several limitations. Although this is the largest reported study to evaluate procedural sedation on older adults, it is possible that the size of the study precluded us from detecting a statistically significant difference among age groups. Multiple nurses participated in monitoring patients, and it is possible that a recording error or omission occurred despite thorough training and standardization of the data collection
C.S. Weaver et al. instrument. Patients were observed in the study only until they appeared to be recovered from sedation. No follow-up data were obtained.
6. Conclusions This study demonstrated no statistically significant difference in EDPS complication rates for patients at least 65 years of age as compared with younger adults. The vast majority of patients included received propofol as the sedative agent. Similar medications were used in all ages, but dosing of medications decreased as age increased. Although there was a trend toward increased event rates in seniors, the physicians in the study may have avoided the statistically significant difference in adverse events by preemptively reducing the dose of sedative delivered in the older age group.
References [1] Burton JH, Miner JR, Shipley ER, Strout TD, Becker C, Thode Jr HC Jr. Propofol for emergency department procedural sedation and analgesia: a tale of three centers. Acad Emerg Med 2006;13(1):24-30. [2] Miner JR, Biros M, Krieg S, Johnson C, Heegaard W, Plummer D. Randomized clinical trial of propofol versus methohexital for procedural sedation during fracture and dislocation reduction in the emergency department. Acad Emerg Med 2003;10(9):931-7. [3] Taylor DM, O'Brien D, Ritchie P, Pasco J, Cameron PA. Propofol versus midazolam/fentanyl for reduction of anterior shoulder dislocation. Acad Emerg Med 2005;12(1):13-9. [4] Chudnofsky CR, Weber JE, Stoyanoff PJ, et al. A combination of midazolam and ketamine for procedural sedation and analgesia in adult emergency department patients. Acad Emerg Med 2000;7(3):228-35 [see comment]. [5] Austin T, Vilke GM, Nyheim E, Kelly D, Chan TC. Safety and effectiveness of methohexital for procedural sedation in the emergency department. J Emerg Med 2003;24(3):315-8. [6] Ruth WJ, Burton JH, Bock AJ. Intravenous etomidate for procedural sedation in emergency department patients. Acad Emerg Med 2001;8 (1):13-8. [7] Vinson DR, Bradbury DR. Etomidate for procedural sedation in emergency medicine. Ann Emerg Med 2002;39(6):592-8. [8] Nawar EW, Niska RW, Xu J. National hospital ambulatory medical care survey: 2005 emergency department summary. Advance Data. (386):1-32, 2007 Jun 29. Hyattsville, MD 20782, USA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Health Statistics. [9] Miner JR, Burton JH. Clinical practice advisory: emergency department procedural sedation with propofol. Ann Emerg Med 2007;50(2): 182-7, 187.e1 [review] [67 refs]. [10] Anethesiologists ASo. Physical status classification system. Available at: http://www.asahq.org/clinical/physicalstatus.htm. [11] Pereira J, Bruera E. (2001). Alberta hospice palliative care resource manual. Division of Palliative Care. A. C. Board. [12] Kazama T, Ikeda K, Morita K, Kikura M, Doe M, Ikeda T, et al. Comparison of the effect-site k(eO)s of propofol for blood pressure and EEG bispectral index in elderly and younger patients. Anesthesiology 1999;90(6):1517-27.
www.elsevier.com/locate/ajem
Original Contribution
ED procedural sedation of elderly patients: is it safe?☆ Christopher S. Weaver MD a,⁎, Kevin M. Terrell DO, MS a,b,c , Robert Bassett DO a , William Swiler DO a , Beth Sandford RN a , Sara Avery RN a , Anthony J. Perkins MS b a
Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, IN, USA Indiana University Center for Aging Research, Indiana University School of Medicine, Indianapolis, IN, USA c Regenstrief Institute, Indiana University School of Medicine, Indianapolis, IN, USA b
Received 9 September 2009; revised 4 November 2009; accepted 15 December 2009
Abstract Objective: Emergency physicians routinely perform emergency department procedural sedation (EDPS), and its safety is well established. We are unaware of any published reports directly evaluating the safety of EDPS in older patients (≥65 years old). Many EDPS experts consider seniors to be at higher risk. The objective was to evaluate the complication rate of EDPS in elderly adults. Methods: This was a prospective, observational study of EDPS patients at least 65 years old, as compared with patients aged 18 to 49 and 50 to 64 years. Physicians were blind to the objectives of this research. The study protocol required an ED nurse trained in data collection to be present to record vital signs and assess for any prospectively defined complications. We used American Society of Anesthesiologists (ASA) physical status classification for systemic disease to evaluate and account for the comorbidities of patients. We used the Fisher exact test for the difference in proportions across age groups and analysis of variance for the differences in dosing across age and ASA categories. Results: During the 4-year study, we enrolled 50 patients at least 65 years old, 149 patients aged 50 to 64 years, and 665 patients aged 18 to 49 years. Adverse event rates were 8%, 5.4%, and 5.2%, respectively (P = .563). The at least 65 years age group represented a greater percentage of those with higher ASA scores (P b .001). The average total sedative dose in the at least 65 years group was significantly lower than the comparisons (P b .001). Conclusions: This study demonstrated no statistically significant difference in complication rate for patients 65 years or older. There was a significant decrease in mean sedation dosing with increased age and ASA score. © 2011 Elsevier Inc. All rights reserved.
1. Introduction In emergency departments (EDs), sedatives and/or analgesics are frequently administered during brief, painful ☆
Presented: Poster presentation at 2009 SAEM Annual Meeting, May 2009, New Orleans, LA. ⁎ Corresponding author. Wishard Memorial Hospital, Indianapolis, IN 46202, USA. Tel.: +1 317 630 7276; fax: +1 317 6564216. E-mail address: [email protected] (C.S. Weaver). 0735-6757/$ – see front matter © 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.ajem.2009.12.017
procedures (eg, fracture or dislocation reduction, abscess incision and drainage, wound care). This process is termed emergency department procedural sedation (EDPS), and various individual sedatives or a combination of sedatives may be used [1-7]. When performed correctly, EDPS is a safe method to minimize pain and awareness of uncomfortable procedures [1-7]. The reported rates of adverse events in adults have ranged from 5% to 20%. Although EDPS has been shown to be safe for adults in general, we are unaware of any published
542 reports that were specifically designed to evaluate the safety of EDPS in older patients. Emergency departments are major providers for older adults. Patients 65 years and older made more than 16.7 million visits to EDs (or 14.5% of all visits) in 2005 [8]. Many EDPS experts consider elderly patients to be at higher risk for adverse events during EDPS [9]. The objective of this research was to evaluate the complication rate of EDPS in older adults as compared with younger adults. In addition to determining adverse event rates, we sought to investigate any differences between older and younger adult patients with respect to success of procedure, medication selection, and medication dosing.
2. Materials and methods 2.1. Study design This was a prospective, observational study of EDPS in older adults. The Indiana University School of Medicine Institutional Review Board approved the study before data collection.
2.2. Study population and setting The study population included all older ED patients (defined as those 65 years or older) who received procedural sedation between January 1, 2004, and January 21, 2008. Procedural sedation was defined as parenteral administration of a medication with sedating properties (with or without an analgesic) to facilitate a procedure in the ED. We compared the study population to all patients aged 18 to 49 and 50 to 64 years who underwent EDPS during the study period. This study was conducted in the ED of an urban, academic, level I trauma center with a volume of approximately 100 000 annual visits.
2.3. Procedures and measurements Standard monitoring and procedures, as required by the hospital's EDPS protocol, were followed. In addition to an emergency physician, the EDPS protocol requires an emergency nurse assistant to be in the room to monitor the vital signs, pulse oximetry, and possible complications and to administer the ordered medications. Data for this research were collected by the emergency nurses. Before data collection, we defined each data point and trained the nurses collecting the data. The trained emergency nurses assessed and recorded vital signs, ventilation, airway evaluation (eg, snoring, partial obstruction, obstruction, signs of aspiration), pulse oximetry, and complications every 5 minutes and nadir. The nurses also documented all administered medications and doses.
C.S. Weaver et al. All emergency physicians, other than the investigators, were blind to the objectives of this research. The emergency medicine attending physician or the emergency medicine resident (under the direct supervision of the attending physician) conducted the procedural sedation in their usual fashion. The emergency physician was responsible for the preprocedure assessment, sedation plan, dosing of medication, completion of the procedure, and standard monitoring of the patient. The frequency and incremental dosing of medication were left to the discretion of the individual treating physician. An analgesic was considered sedation analgesic if it was given less than 5 minutes before the first dose of sedative medication. Complications were prospectively defined as apnea, postprocedure nausea/vomiting, laryngospasm, hypotension, heart rate less than 50 beats per minute or rhythm disturbance, rescue maneuver (ie, head repositioning, jaw thrust, use of oral airway, increase in oxygen administration, increase in stimulation, unplanned use of reversal agents), hypoxemia, aspiration, bag valve mask ventilation, intubation, any blood pressure or heart rate interventions, hospital admission, and death. Apnea was defined as no ventilation effort with no obvious airway obstruction. Systolic blood pressure less than 90 mm Hg was considered hypotension. Bradycardia was defined as a heart rate less than 50 unless the patient had preexisting bradycardia. Any patient with an oxygen saturation less than 90% for more than 10 seconds was considered to be hypoxemic. Aspiration was defined as emesis or reflux from mouth or nose during sedation, coughing or gagging during sedation and subsequent prolonged decrease in oxygen saturation by 5% from baseline, chest x-ray evidence of aspiration, or evidence of aspiration including respiratory complaints, prolonged unexplained cough, or dyspnea. We used the American Society of Anesthesiologists (ASA) physical status classification for systemic disease [10] to evaluate and account for the comorbidities of patients when comparing complications. We enrolled patients in classes I (normal healthy patient), II (mild systemic disease), III (severe systemic disease), and IV (severe systemic disease that is a constant threat to life), but none in class V (moribund patient not expected to live another 24 hours) or VI (braindead patient whose organs are being removed for donor purposes). To compare narcotic dosing, we used a previously published conversion table that equates intravenous morphine 5 mg, intravenous hydromorphone 1 mg, and intravenous fentanyl 100 μg [11].
2.4. Data analysis We used Fisher exact test to compare the proportion of adverse events and unsuccessful procedures across age and ASA categories. χ2 tests were used to compare medication and procedure categories across the 3 age groups. We used 1-way analysis of variance to test for differences in sedation dosage across age groups. All analyses were performed using SAS V9.0 (SAS, Cary, NC).
Elderly procedural sedation
543
3. Results During the 4-year study period, 868 adult patients were enrolled. Age was not recorded for 4 subjects who were excluded from the analysis. Five hundred twenty-nine (61.43%) were male. Fifty (5.8% of all EDPS patients) elderly study subjects were included and compared with 149 (17.2%) in the 50 to 64 age group and 665 (77.0%) in the 18 to 49 group. Four hundred eleven (49%) subjects were white, 337 (39.5%) were black, 85 (10.0%) were Hispanic, and 21 (2.3%) were of other racial/ethnic heritage. Table 1 demonstrates the adverse event rate and procedure success rate across age groups. There was no statistically significant difference (P = .563) in adverse events across age groups, although the oldest age group had the highest adverse event rate. There was a marginally significant difference (P = .086) across age groups when looking at hypotension only. The difference is such that elderly patients had the highest hypotension rate. There were no statistically significant differences across age group for Table 1 Association of age with demographic and clinical characteristics (N = 864) 18-49 y 50-64 y 65+ y P (n = 665) (n = 149) (n = 50) value Adverse event and procedure success % Adverse event % Hypotension % Oxygen saturation % Unsuccessful procedure % Adverse event or unsuccessful procedure ASA score %1 %2 %3 %4 Procedure % Chest tube placement % Dislocation reduction % Hernia reduction % Incision and drainage % Lumbar puncture % Miscellaneous Medications given % Propofol alone % Propofol + narcotic % Versed + narcotic % Other combinations
5.2 2.1 2.6 3.6
5.4 0.7 4.7 3.4
8.0 6.0 2.0 4.0
.563 .086 .346 .943
8.6
8.8
12.0
.676
b.001 43.3 42.2 12.7 1.8
20.1 32.9 40.3 6.7
6.0 32.0 36.0 26.0
4.5
2.0
4.0
64.2
62.4
68.0
2.1 17.8
4.0 14.1
6.0 8.0
2.4 8.9
6.0 11.4
4.0 10.0
49.7 38.8 8.4 3.2
46.6 36.5 8.8 8.1
57.1 38.8 0.0 4.1
.119
.056
oxygen saturation or for an unsuccessful procedure. The combination of an adverse event or unsuccessful procedure did not differ significantly across age. Subjects' ASA scores significantly rose in each increasing age group. There was no difference in the procedures performed across age group, with dislocation reduction accounting for more than 60% of all procedures in each age group. Propofol was the most frequently used sedation agent in each age group. There was a significant difference in the dose of medication given between the age groups, with the older age groups getting lower doses. Among patients in which propofol was the sole agent, the mean dose was 158 mg in the 18 to 49 age group, 124 mg in the 50 to 64 age group, and 106 mg in the at least 65 age group (P b .001). Among subjects who received both narcotic pain medication and propofol, the mean doses of propofol for each group were 172, 133, and 100 mg for age groups 18 to 49, 50 to 64, and at least 65 years, respectively (P = .002). The mean dose of narcotic in this group was not significantly different. With dosing in morphine equivalents, the age groups received 12, 10, and 9 mg, respectively (P = .707). There was no significant difference in adverse events across ASA scores (P = .827). However, the rate of unsuccessful procedures (3.2% for ASA I, 2.3% for ASA II, 5.0% for ASA III, and 11.4% for ASA IV) differed significantly across ASA score (P = .042). There was no significant difference in adverse event rates across procedure type, but there was a significant difference in procedure success across the different procedures performed (P = .001). Hernia reduction resulted in 21% unsuccessful procedures, lumbar puncture was unsuccessful in 11%, whereas all other procedures' unsuccessful rate was less than 5%.
4. Discussion Our prospective, observational study of 868 EDPS patients included 50 patients aged at least 65 years. As we compared these elderly patients with those younger, we found no significant difference in adverse events or procedure success rates. The choice of medication was also similar between the age groups. However, the dose of the sedative agent did decrease as age increased. These findings raise several questions: Are the physicians making a conscious decision to decrease the dose they are giving because the patients are older and therefore protecting against complications in this population thought to be at a higher risk? Or are the patients reaching the adequate level of sedation with a lower dose? Are the patients achieving the same sedation level as those younger? In Miner and Burton's [9] “Clinical practice advisory” on propofol sedation, they reported that lower doses of propofol are required to achieve a defined end point in patients older than 55 years. In addition, they state that the hypotensive effects of propofol are more pronounced with advanced age
544 and that evidence supports an advanced age predisposition to airway and respiratory adverse events [9]. The authors recommend future studies to assess potential differences based on age. Our study evaluated different age groups for adverse events such as hypotension and airway complications. As described above, we did not find a significant difference between the groups in these parameters but did find that lower doses of propofol were used. In a study evaluating the use of propofol for procedural sedation, the average age of patients experiencing oxygen desaturation was higher than those without this complication [1]. Burton et al [1] completed a prospective, descriptive series but were assessing the frequency of respiratory and cardiovascular events in all patients receiving propofol sedation at 3 study sites. They found that the mean age of those who dropped to a SpO2 less than 90% was 51 years as compared with 40 years in those who did not. Increased age was also associated with the need for bag valve mask ventilation (52 years in those with and 41 years in those without). Although Burton and colleagues reported the mean age and range of ages from each institution, they did not report the number of patients older than 65 years and the number of sedation events in that population. In our comparison of patients at least 65 years old to those younger, we did not find a significant difference in respiratory adverse events such as decreased oxygen saturation; and there were no incidents of bag valve mask ventilation in our study. In another study evaluating propofol sedation, Kazama et al [12] found the hypotensive effect of propofol to be more pronounced in those with advanced age. The authors evaluated the effects of propofol demonstrated by electroencephalogram or blood pressure changes compared between elderly and young or middle-aged patients. They performed a controlled infusion to attain specific plasma propofol concentrations. All of their patients were ASA I or II. The systolic blood pressure decreased as propofol plasma concentration increased, with this occurring significantly more readily in those 70 to 85 years of age as compared with those younger. In our study, 6% of those at least 65 years old developed a drop in systolic blood pressure to less than 90 mm Hg as compared with 2.1% and 0.7% in the younger groups.
5. Limitations The interpretation of this study is subject to several limitations. Although this is the largest reported study to evaluate procedural sedation on older adults, it is possible that the size of the study precluded us from detecting a statistically significant difference among age groups. Multiple nurses participated in monitoring patients, and it is possible that a recording error or omission occurred despite thorough training and standardization of the data collection
C.S. Weaver et al. instrument. Patients were observed in the study only until they appeared to be recovered from sedation. No follow-up data were obtained.
6. Conclusions This study demonstrated no statistically significant difference in EDPS complication rates for patients at least 65 years of age as compared with younger adults. The vast majority of patients included received propofol as the sedative agent. Similar medications were used in all ages, but dosing of medications decreased as age increased. Although there was a trend toward increased event rates in seniors, the physicians in the study may have avoided the statistically significant difference in adverse events by preemptively reducing the dose of sedative delivered in the older age group.
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