ORIGINAL ARTICLE
Pulse Oxygen Saturation Values in a Healthy School-Aged Population Joshua W. Elder, MD, MPH,* Suzanne Booth Baraff, BA, MS,† Wesley N. Gaschler, MD,‡ and Larry J. Baraff, MD‡ Objectives: The purpose of this study was to determine the normal values of oxygen saturation in a healthy school-aged pediatric population. Methods: This study enrolled students in grades K-8 at an elementary and middle school in Los Angeles. Although all students were invited to participate, only pulse oximetry results among healthy students were included. Healthy students were defined as not having asthma, bronchitis, a recent cold or pneumonia within the past week, any chronic lung disease, or any heart condition. Results: Two hundred forty-eight students participated in the study, and 246 students met the inclusion criteria. Pulse oxygen saturation values ranged from 97% to 100% with a mean of 98.7% (95% confidence interval [CI], 98.6%–99.8%) and median of 99%. The distribution of measured pulse oximetry values were 97%: 16 (95% CI, 6.5%), 98%: 45 (95% CI, 18.3%), 99%: 184 (95% CI, 74.8%), and 100%: 1 (95% CI, 0.4%). Conclusions: Although the conventional wisdom is that pulse oximetry values 95% or greater are normal, these data suggest that the normal oxygen saturation range should be between 97% and 100%. Values of 95% and 96% should increase clinical suspicion of underlying disease. Key Words: pulse oximetry, pulse oxygen saturation, healthy school-aged population (Pediatr Emer Care 2014;31: 645–647)
S
ince the development of the first pulse oximeter in 1974, pulse oximetry has become a convenient, simple, and noninvasive clinical measurement of arterial oxygen saturation.1 Despite its initial widespread adoption into the medical community and a number of studies documenting its clinical utility in various patient subgroups, the impact of its application on a widespread basis was limited.2–6 This changed in 1995 when Mower et al7,8 described the effect of routine emergency department triage pulse oximetry on the diagnosis and treatment of emergency department patients. These results led 2 years later in 1997 to a report suggesting the use of pulse oximetry as a fifth pediatric vital sign.9 However, normal pulse oximetry values in healthy schoolaged children living at sea level have not been previously determined.10–15 Our study was devised to assess the reference range of oxygen saturations measured with a pulse oximeter in healthy school-aged children at sea level. In clinical practice, the “normal” pulse oximetry value has been estimated to be between 95% and 100%. However, from clinical experience, we suspected that values of 95% and 96% were abnormal. Given the widespread use of this technology in emergency medicine and throughout
From the *Stanford University School of Medicine, Palo Alto; †Calvary Christian School, Pacific Palisades; and ‡David Geffen School of Medicine at UCLA, Los Angeles, CA. Disclosure: The authors declare no conflict of interest. Reprints: Larry J. Baraff, MD, UCLA Emergency Medicine Center, David Geffen School of Medicine at UCLA, 924 Westwood Blvd, Suite 300, Los Angeles, CA 90024 (e‐mail: [email protected]). Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 0749-5161
medical practice, a validation of the normal healthy pediatric range would be useful.
METHODS This was a prospective observational study. It was carried out at the Calvary Christian School located in Pacific Palisades, Calif (altitude 183 ft, 55.6 m). This school has a student body of approximately 300 students who range in age from 5 to 15 years. The school enrolls students in kindergarten through eighth grade. All students were invited to participate in the study. This study was approved by the UCLA institutional review board. Written informed consent was obtained from each student’s parent/guardian before study participation. In addition, verbal consent was obtained on site from students prior to pulse oximetry measurement. Inclusion criterion for the study was enrollment at the school. Exclusion criteria were any of the following medical conditions: asthma, bronchitis, a recent cold or pneumonia within the past week, any chronic lung disease, or heart condition. The study team visited the school on April 18, 2012, and performed all the measurements for the study. The study team went to each classroom, explained the study to the students, and then measured the pulse oximetry reading for all students whose parents consented that their child could participate in the study. Each student had an individual study number to keep the results coded and confidential. Pulse oximetry readings were obtained on the right index finger (Pulse Oximeter Octive Tech 300 CEN; Clinical Guard, Atlanta, Ga). Nail polish removal was provided for students who had nail polish present at the time of the test. If the initial measurement was less than 97%, a repeat measurement was obtained. The protocol called for a second measurement 5 minutes later if the initial measurement was less than 97%. If this second measurement was also less than 97%, a capillary refill measurement would be obtained, and the school nurse would be notified of the child’s test result. The parents of any students identified in this manner were to be called by the school nurse and advised to contact either Dr Baraff or their child’s primary physician to explain the possible meaning of this result.
Sample Size Determination Prior to the initiation of this research, we determined that with 250 participants, there would be only a 1.4% chance of a child having a pulse outside the measured reference range using a 1-sided 97.5% confidence interval (CI) with the Fisher exact test. This would be less than the expected 2.5%. Data were collected and entered into an Excel spreadsheet (Microsoft, 2011; One Microsoft Way, Redmond, WA). STATA 10.1 statistical software (StataCorp LP, 2010; College Station, Texas) was used for data management and statistical tests.
RESULTS We enrolled 248 participants, of whom 2 were excluded from data analysis for having 1 of the exclusion criteria. We did not ask for a specification of the particular underlying disease to protect
Pediatric Emergency Care • Volume 31, Number 9, September 2015
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
www.pec-online.com
645
Pediatric Emergency Care • Volume 31, Number 9, September 2015
Elder et al
TABLE 1. Characteristics of Participants Characteristics
Frequency (%)
Female Race White Asian Black Hispanic Age 5y 6y 7y 8y 9y 10 y 11 y 12 y 13 y 14 y 15 y
126 (51.2) 219 (88.3) 21 (8.5) 5 (2.0) 3 (1.2) 7 (2.9) 25 (10.1) 24 (9.8) 26 (10.6) 32 (13.0) 26 (10.6) 33 (13.4) 29 (11.8) 25 (10.2) 18 (7.3) 1 (0.4)
the confidentiality of the students. The demographic characteristics of the study population are presented in Table 1. Of the 246 students who participated, 51% were female. Students’ ages ranged from 5 to 15 years, with a mean age of 9.8 years. Pulse oxygen saturation measurements ranged from 97% to 100%, with a mean of 98.7 (95% CI, 98.6%–99.8%) and a median value of 99%. The distribution of measured pulse oximetry values is presented in Table 2. There were no pulse oximetry measurements less than 97%. Although the study protocol required repeating pulse oximetry measurement if the initial pulse oximetry measurement was less than 97, none of the 246 participants required repeat measurements. Of note, the 2 students who met the exclusion criteria and were not included in the data analysis had measurements between 97% and 100% (Fig. 1).
This represents the first known determination of the normal pediatric pulse oxygen saturation values among healthy young school-aged children. We found the normal pediatric oxygen saturation to be between 97% and 100%. Mau et al11 measured oxygen saturation values in infants and children admitted to a children's hospital for elective surgery and defined “normal” as “without respiratory symptoms and not scheduled for surgery involving the airway, pulmonary, or cardiovascular systems.” While the study attempted to establish the reference range of oxygen saturation TABLE 2. Pulse Oximetry Results
646
www.pec-online.com
values, the patients selected for the study limited the generalizability of the results. However, the authors concluded that 95% and 96% “should be considered potentially abnormal.” Worldwide, other studies have established varying pulse oximetry readings with altitude and age. In terms of age, Balasubramanian et al12 established the reference mean of oxygen saturation among children from 1 month to 5 years as 98.5%. The authors reported an increase of mean SaO2 among age groups (1–3 months, 3 months to 1 year, 1–3 years, and 3–5 years were 98.5%, 98.8%, 98.9%, and 99.1%, respectively). Laman et al13 also showed an increase among children younger than 5 years with a range of 93% to 100%. There have been multiple documented reports demonstrating a decrease in mean oxygen saturation with increasing altitude.14,15 Our results represent an important recalibration in our assessment of children between the ages of 5 to 15 years. With pulse oximetry now routinely used as a fifth vital sign in emergency medicine, it is important that the normal values be known. Our data combined with the studies referenced above suggest that 97% to 100% should be considered the reference range for pediatric patients at sea level.
Limitations
DISCUSSION
SaO2, Mean (95% CI) SaO2, Median SaO2 ≤96% 97% 98% 99% 100%
FIGURE 1. Pulse oximetry distribution.
98.7% (98.6%–99.8%) 99% Frequency, n (%) 0 (0.0) 16 (6.5) 45 (18.3) 184 (74.8) 1 (0.4)
Limitations of the pulse oximetry include but are not limited to the following: motion artifacts, poor perfusion, skin pigmentation, nail polish or artificial nails, irregular heart rhythms, ambient light interference, and electromagnetic interference.10 We attempted to minimize these interruptions in the study design by having the students sit and remain still during the measurement, removing nail polish when necessary, excluding students with known underlying disease, and utilizing a modern device that attempts to minimize interruptions such as ambient light interference. Our study population was composed of primarily white children. Theoretically, pulse oximetry should not be impacted by skin pigmentation because the device is designed to adjust its calculation for alternative levels of light absorption.10 Previous research has only demonstrated spurious results when oxygen saturation values fall beneath 80%.16,17 Of the approximately 300 students enrolled in the school, 248 participated. We did not obtain any information on those students whose parents did not complete the informed consent, making it impossible to know whether they met one of the exclusion criteria, were opposed to the study, or did not meet the timeline necessary to return the consent documentation. Although we protected the identity of our participants by not requiring students to identify which particular exclusion criteria applied, this limited © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Pediatric Emergency Care • Volume 31, Number 9, September 2015
our understanding of the students excluded from the study. Our study did not attempt to measure the pulse oxygenation of students known to meet one of the exclusion criteria. Even though the purpose of the study was to measure the reference range of healthy students, it would have provided a useful comparison to note the range among the exclusion group.
CONCLUSIONS This is the first known study to assess the reference range of oxygen saturation among a healthy school-aged children at sea level. Although the conventional wisdom has been that values of 95% and higher should be included in the normal oxygen saturation range, these data suggest that the normal oxygen saturation range should be between 97% and 100% in this patient population. Children with these pulse oximetry values of 95% and possibly 96%, which are verified when repeated, may have unrecognized pulmonary or cardiac disease. ACKNOWLEDGMENT The authors thank the staff and students of Calvary Christian School whose help and support made this research study a possibility. REFERENCES
Pulse Oxygen Saturation Values
6. Kellerman AL, Cofer CA, Joseph S, et al. Impact of portable pulse oximetry on arterial blood gas test ordering in an urban emergency department. Ann Emerg Med. 1991;20:130–134. 7. Mower WR, Sachs C, Nicklin E, et al. Effect of routine emergency department triage pulse oximetry screening on medical management. Chest. 1995;108:1297–1302. 8. Mower WR, Sachs C, Nicklin E, et al. A comparison of pulse oximetry and respiratory rate in patient screening. Respir Med. 1996;90: 593–599. 9. Mower WR, Sachs C, Nicklin EL, et al. Pulse oximetry as a fifth vital sign in emergency geriatric assessment. Acad Emerg Med. 1998;5: 858–865. 10. Fouzas S, Priftis KN, Anthracopoulos MB. Pulse oximetry in pediatric practice. Pediatrics. 2011;128:740–752. 11. Mau MK, Yamasato KS, Yamamoto LG. Normal oxygen saturation values in pediatric patients. Hawaii Med J. 2005;64:42 44–45. 12. Balasubramanian S, Suresh N, Ravichandran C, et al. Reference values for oxygen saturation by pulse oximetry in healthy children at sea level in Chennai. Ann Trop Paediatr. 2006;26:95–99. 13. Laman M, Ripa P, Vince JD, et al. Reference values for pulse oximetry in healthy children in coastal Papua New Guinea. P N G Med J. 2009;52:8–12.
1. Severinghaus JW. Takuo Aoyagi: discovery of pulse oximetry. Anesth Analg. 2007;105(suppl 6):S1–S4, table of contents.
14. Huicho L, Pawson IG, León-Velarde F, et al. Oxygen saturation and heart rate in healthy school children and adolescents living at high altitude. Am J Hum Biol. 2001;13:761–770.
2. Jones J, Heiselman D, Cannon L, et al. Continuous emergency department monitoring of arterial saturation in adult patients with respiratory distress. Ann Emerg Med. 1988;17:463–468.
15. Weitz CA, Garrutto RM. A comparative analysis of arterial oxygen saturation among Tibetans and Han born and raised at high altitude. High Alt Med Biol. 2007;8:13–26.
3. Holburn CJ, Allen MJ. Pulse oximetry in the accident and emergency department. Arch Emerg Med. 1989;6:137–142. 4. Lambert MA, Crinnion J. The role of pulse oximetry in the accident and emergency department. Arch Emerg Med. 1989;6:211–215.
16. Feiner JR, Severinghaus JW, Bickler PE. Dark skin decreases the accuracy of pulse oximeters at low oxygen saturation: the effects of oximeter probe type and gender. Anesth Analg. 2007;105(suppl 6): S18–S23.
5. Rosen LM, Yamamoto LG, Wiebe RA. Pulse oximetry to identify a high-risk group of children with wheezing. Am J Emerg Med. 1989;7: 567–570.
17. Bickler PE, Feiner JR, Severinghaus JW. Effects of skin pigmentation on pulse oximeter accuracy at low saturation. Anesthesiology. 2005;102: 715–719.
© 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
www.pec-online.com
647
Pulse Oxygen Saturation Values in a Healthy School-Aged Population Joshua W. Elder, MD, MPH,* Suzanne Booth Baraff, BA, MS,† Wesley N. Gaschler, MD,‡ and Larry J. Baraff, MD‡ Objectives: The purpose of this study was to determine the normal values of oxygen saturation in a healthy school-aged pediatric population. Methods: This study enrolled students in grades K-8 at an elementary and middle school in Los Angeles. Although all students were invited to participate, only pulse oximetry results among healthy students were included. Healthy students were defined as not having asthma, bronchitis, a recent cold or pneumonia within the past week, any chronic lung disease, or any heart condition. Results: Two hundred forty-eight students participated in the study, and 246 students met the inclusion criteria. Pulse oxygen saturation values ranged from 97% to 100% with a mean of 98.7% (95% confidence interval [CI], 98.6%–99.8%) and median of 99%. The distribution of measured pulse oximetry values were 97%: 16 (95% CI, 6.5%), 98%: 45 (95% CI, 18.3%), 99%: 184 (95% CI, 74.8%), and 100%: 1 (95% CI, 0.4%). Conclusions: Although the conventional wisdom is that pulse oximetry values 95% or greater are normal, these data suggest that the normal oxygen saturation range should be between 97% and 100%. Values of 95% and 96% should increase clinical suspicion of underlying disease. Key Words: pulse oximetry, pulse oxygen saturation, healthy school-aged population (Pediatr Emer Care 2014;31: 645–647)
S
ince the development of the first pulse oximeter in 1974, pulse oximetry has become a convenient, simple, and noninvasive clinical measurement of arterial oxygen saturation.1 Despite its initial widespread adoption into the medical community and a number of studies documenting its clinical utility in various patient subgroups, the impact of its application on a widespread basis was limited.2–6 This changed in 1995 when Mower et al7,8 described the effect of routine emergency department triage pulse oximetry on the diagnosis and treatment of emergency department patients. These results led 2 years later in 1997 to a report suggesting the use of pulse oximetry as a fifth pediatric vital sign.9 However, normal pulse oximetry values in healthy schoolaged children living at sea level have not been previously determined.10–15 Our study was devised to assess the reference range of oxygen saturations measured with a pulse oximeter in healthy school-aged children at sea level. In clinical practice, the “normal” pulse oximetry value has been estimated to be between 95% and 100%. However, from clinical experience, we suspected that values of 95% and 96% were abnormal. Given the widespread use of this technology in emergency medicine and throughout
From the *Stanford University School of Medicine, Palo Alto; †Calvary Christian School, Pacific Palisades; and ‡David Geffen School of Medicine at UCLA, Los Angeles, CA. Disclosure: The authors declare no conflict of interest. Reprints: Larry J. Baraff, MD, UCLA Emergency Medicine Center, David Geffen School of Medicine at UCLA, 924 Westwood Blvd, Suite 300, Los Angeles, CA 90024 (e‐mail: [email protected]). Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. ISSN: 0749-5161
medical practice, a validation of the normal healthy pediatric range would be useful.
METHODS This was a prospective observational study. It was carried out at the Calvary Christian School located in Pacific Palisades, Calif (altitude 183 ft, 55.6 m). This school has a student body of approximately 300 students who range in age from 5 to 15 years. The school enrolls students in kindergarten through eighth grade. All students were invited to participate in the study. This study was approved by the UCLA institutional review board. Written informed consent was obtained from each student’s parent/guardian before study participation. In addition, verbal consent was obtained on site from students prior to pulse oximetry measurement. Inclusion criterion for the study was enrollment at the school. Exclusion criteria were any of the following medical conditions: asthma, bronchitis, a recent cold or pneumonia within the past week, any chronic lung disease, or heart condition. The study team visited the school on April 18, 2012, and performed all the measurements for the study. The study team went to each classroom, explained the study to the students, and then measured the pulse oximetry reading for all students whose parents consented that their child could participate in the study. Each student had an individual study number to keep the results coded and confidential. Pulse oximetry readings were obtained on the right index finger (Pulse Oximeter Octive Tech 300 CEN; Clinical Guard, Atlanta, Ga). Nail polish removal was provided for students who had nail polish present at the time of the test. If the initial measurement was less than 97%, a repeat measurement was obtained. The protocol called for a second measurement 5 minutes later if the initial measurement was less than 97%. If this second measurement was also less than 97%, a capillary refill measurement would be obtained, and the school nurse would be notified of the child’s test result. The parents of any students identified in this manner were to be called by the school nurse and advised to contact either Dr Baraff or their child’s primary physician to explain the possible meaning of this result.
Sample Size Determination Prior to the initiation of this research, we determined that with 250 participants, there would be only a 1.4% chance of a child having a pulse outside the measured reference range using a 1-sided 97.5% confidence interval (CI) with the Fisher exact test. This would be less than the expected 2.5%. Data were collected and entered into an Excel spreadsheet (Microsoft, 2011; One Microsoft Way, Redmond, WA). STATA 10.1 statistical software (StataCorp LP, 2010; College Station, Texas) was used for data management and statistical tests.
RESULTS We enrolled 248 participants, of whom 2 were excluded from data analysis for having 1 of the exclusion criteria. We did not ask for a specification of the particular underlying disease to protect
Pediatric Emergency Care • Volume 31, Number 9, September 2015
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
www.pec-online.com
645
Pediatric Emergency Care • Volume 31, Number 9, September 2015
Elder et al
TABLE 1. Characteristics of Participants Characteristics
Frequency (%)
Female Race White Asian Black Hispanic Age 5y 6y 7y 8y 9y 10 y 11 y 12 y 13 y 14 y 15 y
126 (51.2) 219 (88.3) 21 (8.5) 5 (2.0) 3 (1.2) 7 (2.9) 25 (10.1) 24 (9.8) 26 (10.6) 32 (13.0) 26 (10.6) 33 (13.4) 29 (11.8) 25 (10.2) 18 (7.3) 1 (0.4)
the confidentiality of the students. The demographic characteristics of the study population are presented in Table 1. Of the 246 students who participated, 51% were female. Students’ ages ranged from 5 to 15 years, with a mean age of 9.8 years. Pulse oxygen saturation measurements ranged from 97% to 100%, with a mean of 98.7 (95% CI, 98.6%–99.8%) and a median value of 99%. The distribution of measured pulse oximetry values is presented in Table 2. There were no pulse oximetry measurements less than 97%. Although the study protocol required repeating pulse oximetry measurement if the initial pulse oximetry measurement was less than 97, none of the 246 participants required repeat measurements. Of note, the 2 students who met the exclusion criteria and were not included in the data analysis had measurements between 97% and 100% (Fig. 1).
This represents the first known determination of the normal pediatric pulse oxygen saturation values among healthy young school-aged children. We found the normal pediatric oxygen saturation to be between 97% and 100%. Mau et al11 measured oxygen saturation values in infants and children admitted to a children's hospital for elective surgery and defined “normal” as “without respiratory symptoms and not scheduled for surgery involving the airway, pulmonary, or cardiovascular systems.” While the study attempted to establish the reference range of oxygen saturation TABLE 2. Pulse Oximetry Results
646
www.pec-online.com
values, the patients selected for the study limited the generalizability of the results. However, the authors concluded that 95% and 96% “should be considered potentially abnormal.” Worldwide, other studies have established varying pulse oximetry readings with altitude and age. In terms of age, Balasubramanian et al12 established the reference mean of oxygen saturation among children from 1 month to 5 years as 98.5%. The authors reported an increase of mean SaO2 among age groups (1–3 months, 3 months to 1 year, 1–3 years, and 3–5 years were 98.5%, 98.8%, 98.9%, and 99.1%, respectively). Laman et al13 also showed an increase among children younger than 5 years with a range of 93% to 100%. There have been multiple documented reports demonstrating a decrease in mean oxygen saturation with increasing altitude.14,15 Our results represent an important recalibration in our assessment of children between the ages of 5 to 15 years. With pulse oximetry now routinely used as a fifth vital sign in emergency medicine, it is important that the normal values be known. Our data combined with the studies referenced above suggest that 97% to 100% should be considered the reference range for pediatric patients at sea level.
Limitations
DISCUSSION
SaO2, Mean (95% CI) SaO2, Median SaO2 ≤96% 97% 98% 99% 100%
FIGURE 1. Pulse oximetry distribution.
98.7% (98.6%–99.8%) 99% Frequency, n (%) 0 (0.0) 16 (6.5) 45 (18.3) 184 (74.8) 1 (0.4)
Limitations of the pulse oximetry include but are not limited to the following: motion artifacts, poor perfusion, skin pigmentation, nail polish or artificial nails, irregular heart rhythms, ambient light interference, and electromagnetic interference.10 We attempted to minimize these interruptions in the study design by having the students sit and remain still during the measurement, removing nail polish when necessary, excluding students with known underlying disease, and utilizing a modern device that attempts to minimize interruptions such as ambient light interference. Our study population was composed of primarily white children. Theoretically, pulse oximetry should not be impacted by skin pigmentation because the device is designed to adjust its calculation for alternative levels of light absorption.10 Previous research has only demonstrated spurious results when oxygen saturation values fall beneath 80%.16,17 Of the approximately 300 students enrolled in the school, 248 participated. We did not obtain any information on those students whose parents did not complete the informed consent, making it impossible to know whether they met one of the exclusion criteria, were opposed to the study, or did not meet the timeline necessary to return the consent documentation. Although we protected the identity of our participants by not requiring students to identify which particular exclusion criteria applied, this limited © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Pediatric Emergency Care • Volume 31, Number 9, September 2015
our understanding of the students excluded from the study. Our study did not attempt to measure the pulse oxygenation of students known to meet one of the exclusion criteria. Even though the purpose of the study was to measure the reference range of healthy students, it would have provided a useful comparison to note the range among the exclusion group.
CONCLUSIONS This is the first known study to assess the reference range of oxygen saturation among a healthy school-aged children at sea level. Although the conventional wisdom has been that values of 95% and higher should be included in the normal oxygen saturation range, these data suggest that the normal oxygen saturation range should be between 97% and 100% in this patient population. Children with these pulse oximetry values of 95% and possibly 96%, which are verified when repeated, may have unrecognized pulmonary or cardiac disease. ACKNOWLEDGMENT The authors thank the staff and students of Calvary Christian School whose help and support made this research study a possibility. REFERENCES
Pulse Oxygen Saturation Values
6. Kellerman AL, Cofer CA, Joseph S, et al. Impact of portable pulse oximetry on arterial blood gas test ordering in an urban emergency department. Ann Emerg Med. 1991;20:130–134. 7. Mower WR, Sachs C, Nicklin E, et al. Effect of routine emergency department triage pulse oximetry screening on medical management. Chest. 1995;108:1297–1302. 8. Mower WR, Sachs C, Nicklin E, et al. A comparison of pulse oximetry and respiratory rate in patient screening. Respir Med. 1996;90: 593–599. 9. Mower WR, Sachs C, Nicklin EL, et al. Pulse oximetry as a fifth vital sign in emergency geriatric assessment. Acad Emerg Med. 1998;5: 858–865. 10. Fouzas S, Priftis KN, Anthracopoulos MB. Pulse oximetry in pediatric practice. Pediatrics. 2011;128:740–752. 11. Mau MK, Yamasato KS, Yamamoto LG. Normal oxygen saturation values in pediatric patients. Hawaii Med J. 2005;64:42 44–45. 12. Balasubramanian S, Suresh N, Ravichandran C, et al. Reference values for oxygen saturation by pulse oximetry in healthy children at sea level in Chennai. Ann Trop Paediatr. 2006;26:95–99. 13. Laman M, Ripa P, Vince JD, et al. Reference values for pulse oximetry in healthy children in coastal Papua New Guinea. P N G Med J. 2009;52:8–12.
1. Severinghaus JW. Takuo Aoyagi: discovery of pulse oximetry. Anesth Analg. 2007;105(suppl 6):S1–S4, table of contents.
14. Huicho L, Pawson IG, León-Velarde F, et al. Oxygen saturation and heart rate in healthy school children and adolescents living at high altitude. Am J Hum Biol. 2001;13:761–770.
2. Jones J, Heiselman D, Cannon L, et al. Continuous emergency department monitoring of arterial saturation in adult patients with respiratory distress. Ann Emerg Med. 1988;17:463–468.
15. Weitz CA, Garrutto RM. A comparative analysis of arterial oxygen saturation among Tibetans and Han born and raised at high altitude. High Alt Med Biol. 2007;8:13–26.
3. Holburn CJ, Allen MJ. Pulse oximetry in the accident and emergency department. Arch Emerg Med. 1989;6:137–142. 4. Lambert MA, Crinnion J. The role of pulse oximetry in the accident and emergency department. Arch Emerg Med. 1989;6:211–215.
16. Feiner JR, Severinghaus JW, Bickler PE. Dark skin decreases the accuracy of pulse oximeters at low oxygen saturation: the effects of oximeter probe type and gender. Anesth Analg. 2007;105(suppl 6): S18–S23.
5. Rosen LM, Yamamoto LG, Wiebe RA. Pulse oximetry to identify a high-risk group of children with wheezing. Am J Emerg Med. 1989;7: 567–570.
17. Bickler PE, Feiner JR, Severinghaus JW. Effects of skin pigmentation on pulse oximeter accuracy at low saturation. Anesthesiology. 2005;102: 715–719.
© 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
www.pec-online.com
647
