пятница, 14 сентября 2012 г.

Pediatric health care providers' knowledge of pulse oximetry.(Continuing Education Series) - Pediatric Nursing

Pulse oximetry provides a noninvasive, painless, and reliable method to measure arterial oxygen saturation. This technology adds valuable data to the assessment of the pediatric practitioner. Ten years ago these devices were mainly found in operating rooms and some intensive care units. Since that time, they have entered into routine use for both continuous and episodic measurement of oxygen saturation of patients in clinics, physician offices, emergency departments, and ambulances. This measurement is now considered by many to be a component of routine vital signs.

Like the other vital sign parameters, these data need to be interpreted so the significance of the reading in relation to patient condition may be assessed. This requires the practitioner to be familiar with the monitoring equipment to determine if accurate data were obtained as well as knowledge regarding what is being measured and the potential physiologic impact of the results obtained. These data points are integrated with other physical assessment to determine clinical patient stability. Health care providers' knowledge may not always be sufficient. The lack of knowledge may affect the providers' patient care decisions, potentially adversely affecting patient outcomes. This research study was conducted to assess pediatric health care providers' knowledge of pulse oximetry and their clinical interpretation of selected patient scenarios.

Literature Review

Rodriguez, Kotin, Lowenthal, and Kattan (1994) attempted to quantify pediatric house staffs' knowledge of pulse oximetry and their ability to interpret the resulting data. These researchers administered a 16-item questionnaire, consisting of 6 demographic elements and 10 knowledge questions, to 100 residents. According to their results, 57% of the respondents felt they had adequate training in pulse oximetry, while 43% did not know what a pulse oximeter measured. Of the 10 knowledge questions, 3 concerned the oxygen dissociation curve. More than half (59%) of the participants answered at least 2 of these questions incorrectly. The researchers concluded that a marked variability exists in the levels of understanding of pulse oximetry among pediatric residents and that the clinicians' knowledge is often inadequate for making appropriate treatment decisions. They recommended increased emphasis on the teaching of the principles and application of pulse oximetry.

Stoneham, Saville, and Wilson (1994) conducted a survey of 30 staff nurses and 30 house officers working on 10 general medical surgical wards in England. Questions addressed the theory behind pulse oximetry, factors influencing readings, values in hypothetical clinical situations, and training the subjects had received. A startling 97% of participants did not understand how an oximeter worked and were confused about factors influencing readings; 30% of physicians and 98% of nurses thought that pulse oximetry also measured the partial pressure of oxygen. Participants also made serious errors in interpreting saturation readings in hypothetical clinical situations. Only 7% of nurses and 17% of physicians understood that in cardiac arrest the oximeter would not calculate a reading due to the lack of pulsatile flow. These researchers concluded that the errors made by the practitioners surveyed indicated a lack of understanding of the physiologic principles of pulse oximetry and that specific training in the theory and techniques of pulse oximetry for physicians and nurses is essential.

Kruger and Longden (1997) conducted a similar survey-based study of physicians, nurses, and anesthesia technicians in an Australian hospital. These researchers avoided multiple-choice questions as they felt the prompts of the options provided would lead to inaccurate assessment of the subjects' knowledge; thus seven of the study's knowledge elements were formatted as open-ended, short-answer questions. Researchers coded answers as correct, partially correct, or incorrect. In this study, 39% of the participants felt they had adequate training in pulse oximetry and 69% correctly reported that pulse oximeters measured oxygen saturation. However, 88% were not aware of the basic relationship between oxygen saturation and the partial pressure of oxygen in arterial blood (oxygen dissociation curve). Kruger and Longden (1997) concluded that there was a general lack of knowledge of pulse oximetry in the study sample. They also recommended that appropriate education regarding pulse oximetry needed to be initiated so that hospital staff would be able to reliably interpret pulse oximetry data.

Pulse Oximetry Technology

Pulse oximetry measurement reflects the percentage of hemoglobin that is capable of transporting oxygen in the blood. Oxygen is carried in the blood in two ways, bound to hemoglobin or dissolved in plasma. Each molecule of hemoglobin is capable of combining with up to four molecules of oxygen; however, not all hemoglobin molecules may be fully saturated with oxygen. The oximeter sensor is typically attached to a peripheral measurement site, such as a digit, palm of the hand or foot in small children, and possibly the earlobe or bridge of the nose for older children. Intense wavelengths of red and infrared light are emitted by one surface of the oximeter sensor probe. The other surface of the probe has a light sensor detector and measures the amount and absorption of the light as it passes through a pulsating vascular bed. Oxygenated blood absorbs more light in the infrared spectrum, and deoxygenated blood absorbs more light in the red spectrum. Using the measurements of light transmission, the pulse oximeter provides a value by calculating the proportion of infrared light to total of infrared and red light detected (Miller, 1992). The values are transformed to correspond to hemoglobin saturation. The estimate of hemoglobin saturation that is derived from these measurements is called 'Sp[O.sub.2].' The Sp[O.sub.2] is oxygenated hemoglobin expressed as a percentage of the hemoglobin that is capable of transporting oxygen.

When the P[O.sub.2] is low, as in peripheral tissues, oxygen is released from the hemoglobin; when the P[O.sub.2] is high, as in the pulmonary arterial beds, the oxygen binds with hemoglobin. This is the basis of normal oxygen transport. The pressure of oxygen in arterial blood of a patient with normal levels of arterial oxygen is approximately 95 mm Hg (see Figure 1). This corresponds to an oxygen saturation of hemoglobin of approximately 97%. A saturation of 99% or 100% could reflect a partial pressure of 100 mm Hg to 140 mm Hg. But, a saturation of 90% corresponds to a partial pressure of approximately 60 mm Hg, and a saturation of 60% corresponds to a partial pressure of 30 mm Hg (see Figure 1). The relationship between the partial pressure of oxygen in arterial blood (Pa[O.sub.2]) and oxygen saturation Sa[O.sub.2] is not linear. Rather, the relationship results in an S-shaped curve. This becomes a crucial concept for practitioners interpreting oximeters, as a fall in oximetry saturation readings corresponds to a more dramatic fall in the partial pressure of oxygen in arterial blood. If the relationship between Pa[O.sub.2] and Sa[O.sub.2] was viewed as linear, health care providers would erroneously interpret a Sa[O.sub.2] of 80% to correspond with a Pa[O.sub.2] of 80 mm Hg. The practitioner would not likely be concerned until the Pa[O.sub.2] was dangerously low. If however, the practitioner understood the non-linear nature of the curve, the Sa[O.sub.2] of 80% would be interpreted to correspond to a Pa[O.sub.2] of 50 mm Hg, indicating significant hypoxemia.


Factors Influencing Accuracy of Data

Oximetry readings can be altered by a number of factors. The site of measurement must be clean and dry and have minimal movement to permit adequate signal transmission. Nail polish and other environmental factors such as bright overhead lighting or sunlight can also interfere with transmission. Cold ambient temperature, leading to peripheral vasoconstriction, decreases skin blood flow and may result in difficulty for the oximeter to determine pulsatile flow needed for a reading. Patient conditions that likewise are associated with poor peripheral perfusion, such as decreased cardiac output, some dysrhythmias, shock, and certainly cardiac arrest, make it unlikely the oximeter will identify pulsatile flow and a valid reading (Murray & Loughlin, 1995).


As vital as pulse oximetry data are becoming in patient care, the technology involved is relatively new. Practitioners have not uniformly had formal training in this area. Three previous studies attempted to measure clinicians' knowledge about oximetry technology. Oximetry use has become more commonplace in clinical settings since the previous studies were conducted. The purpose of this study was to measure the knowledge of pediatric residents, nurses, and respiratory therapists and technicians regarding oximetry and the ability to apply it in a clinical scenario.


This study took place in a large teaching hospital in the Southeastern U.S. Based on clinical expertise, the researchers developed a 19-point survey that included both multiple choice and short-answer questions centering around three themes: (a) the parts and function of the oximeter, (b) interpretation of oximetry readings, and (c) application of pulse oximetry readings. The survey also included demographic elements (see Table 1).

Following the initial development of the survey, eight nurses in a pediatric intensive care unit completed the survey as part of a pilot study designed to elicit feedback on clarity, readability, responder fatigue, and length of time to complete the survey. The nurses in the pilot study did not recommend any changes to the survey wording or format.

After receiving Institutional Review Board (IRB) approval, the surveys were distributed to pediatric residents, respiratory therapists and technicians, and nurses working on a general pediatric unit. All participants were asked to return the surveys whether or not they chose to participate. Respondents were assured of confidentiality and anonymity. The nurses were given the survey during a shift and asked to return it as soon as possible during that shift. The physicians were surveyed during one of their general meetings; surveys were completed and returned at the time of distribution. The respiratory practitioners completed and returned their surveys at change of shift. These short time frames were chosen to minimize the possibility of respondents discussing answers or consulting sources that could help them complete the survey. The researchers did not review the surveys until all data collection periods were completed.

The surveys (see Table 2) were coded independently by each of the three members of the research team. Questions 1 through 4, 6, and 7 were coded as correct, incorrect, or incomplete. Question 5 asked respondents to provide the normal ranges of oxygen saturation for infants, children, and adults. This item was coded as the high and low values the respondents had provided. Questions 8 and 9, which required the respondents to describe the effects of certain factors on pulse oximetry readings, were coded as increased, decreased, no change, or no reading. The four clinical scenarios wee initially coded as correct, incorrect, or incomplete. Subsequent coding was done to distinguish minimally correct responses from more in-depth correct responses. The researchers compared their individual codings and reached a consensus on all the surveys.


The survey distribution methodology may have influenced the results. No one method of distribution was feasible for all practitioner groups. The methodologies used meant that all three groups were faced with time constraints for completion of the survey. Nurses were trying to complete the surveys during the course of a busy shift and were frequently interrupted during survey completion to attend to patient care priorities. The respiratory practitioners were asked to complete the surveys at their change of shift, giving them quite a limited time frame for survey completion. The physicians completed the survey during an educational meeting; consequently their attention may have been divided.

Several subjects expressed anxiety about their lack of knowledge on the subject matter and fear that their answers would not be anonymous. The amount of time used by study participants to complete the survey was much greater than the amount of time that nurses in the pilot study had needed. Thus, the time needed to complete the surveys was underestimated and may have contributed to incomplete responses and increased anxiety on the part of the participants.


Demographics. Researchers distributed a total of 88 surveys, of which 68 were returned, for a return rate of 77%. Two of the returned surveys were so incomplete they could not be used; thus, 66 surveys were used in data analysis. The 66 respondents included 15 physicians, 42 registered nurses (RNs), and 9 respiratory practitioners. Of the nurses, 45% had AD degrees, 2% were diploma school graduates, 48% had BSN degrees, and 5% had MSN degrees. Nurses had the most patient-related experience; of the 24% of all respondents that had greater than 10 years' clinical experience, 87.5% were nurses. More than half (55%) of the RNs had 5 or more years of clinical experience, while all of the MDs in the study had less than 4 years of patient-related experience. The 5 respiratory therapists and 4 respiratory technicians who completed the survey were grouped together for analysis as respiratory practitioners. The number of years of patient-related experience for respiratory practitioners was evenly distributed from less than 6 months to greater than 10 years.

Nurses had the most experience with the use of pulse oximetry equipment; of the 30% of all respondents who had more than 5 years' experience using pulse oximetry, 80% were nurses. All but one of the physicians had less than 4 years' experience. Respiratory practitioners' pulse oximetry experience corresponded with their patient-related experience and was evenly distributed from less than 6 months to greater than 10 years.

Although the majority of respondents received only informal bedside training in the use of pulse oximeters (80% of physicians, 88% of nurses, and 78% of respiratory practitioners), overall, 83% believed they had adequate training.

Knowledge questions. Knowledge related to pulse oximetry function and measurement was quite variable among respondents. Nurses (90%), physicians (66%), and respiratory technicians (77%) believed that they had received adequate training using pulse oximetry equipment. However, when asked to describe how pulse oximetry worked, only 26% of the nurses responded correctly, a significantly smaller number than for physicians or respiratory practitioners (60% and 78%, respectively; p < .001). For an answer to be correct, the respondent must have mentioned a light sensor, red/infrared light absorption, and/or pulsatile blood flow in their response.

The fact that pulse oximetry measures the oxygen saturation of hemoglobin as well as the pulse rate was understood by 100% of physicians, 89% of respiratory practitioners, and 76% of nurses. There was no difference between the practitioner groups (p = .01 ). Knowledge of the oxyhemoglobin dissociation curve as it relates to pulse oximetry was one of the least understood concepts by all respondents; only 5% of nurses, 11% of respiratory practitioners, and 47% of physicians provided the correct answer to the question related to the curve, with physicians significantly more knowledgeable than nurses or respiratory practitioners (p < .00001). While 38% of nurses and 73% of physicians correctly identified the unit of measure for pulse oximetry values as percentage, fewer (12% of nurses, 47% of physicians) identified the unit of measure for the partial pressure of oxygen in blood as millimeters of mercury. The difference between nurses' and physicians' knowledge regarding unit of measure for each of these parameters was significant (p = .001 for Sp[O.sub.2] and p < .00001 for Pa[O.sub.2]). Respiratory practitioners were not included in this portion of data analysis due to the small number responding to these two questions.

Factors influencing accuracy of pulse oximetry readings. The pulse oximeter requires a pulsatile signal and will alarm when it cannot detect the peripheral pulse. One question tested whether respondents knew that immediately after a cardiac arrest or in the event of shock, the signal would be lost and there would be no reading. When this question regarding cardiac arrest was posed in the 1994 Stoneham study, two nurses (7%) and five physicians (17%) answered it correctly. The current study revealed similar results with 17% of nurses, 27% of physicians, and 22% of respiratory practitioners answering correctly. Differences among practitioner groups were not statistically significant. Yet, in the event of a respiratory arrest, 87% of physicians, 77% of nurses, and 44% of respiratory practitioners correctly identified that the saturation would decrease, perhaps with the understanding that saturations during respiratory arrest fall until hypoxia results in cardiac arrest.

Respondents were asked to identify how common factors might affect the accuracy of pulse oximetry readings. The factors were divided into life threatening, physiologic, and environmental situations. The numbers of correct responses by discipline are shown in Table 3. Overall, there was a surprising lack of knowledge related to the impact of these factors by physicians, nurses, and respiratory practitioners; however, no significant differences were demonstrated between these groups. Cardiac arrest, by definition, would result in no pulsatile flow needed for this technology to function; however, only 27% of physicians, 17% of nurses, and 22% of respiratory practitioners recognized this fact. Of the three groups of factors, all respondents were more likely to recognize that physiologic factors such as dark skin and jaundice did not alter the readings. Of the physiologic factors, anemia was the least correctly recognized factor by all groups (20% physicians, 14% nurses, and 33% respiratory practitioners). Environmental factors as a whole yielded fewer correct responses. Only 20% of physicians, 17% of nurses, and 11% of respiratory practitioners recognized that bright light or sunshine on the sensor probe would potentially falsely increase the saturation reading. Additionally, there was a lack of appreciation that nail polish or cold environment could result in the probe failing to detect an adequate signal.

Practitioners were asked to identify the normal range of oxygen saturation in arterial blood for adults, children, and infants. Pediatric nurses identified a lower mean 'low normal' for adults than they did for children or infants (adult = 91.6%, child = 93.3%, infant = 93.6%; NS). Physicians identified similar means as nurses (adult = 94%, child = 94%, and infant = 93.5%; NS). Respiratory practitioners consistently identified the lowest mean 'low normal' of all the practitioners (adult = 91.2%, child = 91.6%, infant = 91.8%; NS).

Clinical Scenarios

Four clinical scenarios were presented in the survey, and respondents were asked to identify appropriate responses or courses of action. The scenarios were designed to assess the clinical judgment and decision-making ability of pediatric practitioners. None of the respiratory practitioners chose to complete this portion of the survey.

Scenario number 1. This scenario involved a child with RSV. Respondents were asked what the implications of the oximetry reading were.

Components of a correct response. The heart rate readings on the two monitors correlate indicating a true desaturation. The Pa[O.sub.2] has decreased from approximately 90 mm Hg to 60 mm Hg. The practitioner should first check the airway, breathing, and circulation; increase the oxygen flow rate; and notify the physician if appropriate.

Results. Significantly fewer of the physicians (27%) than of the nurses (43%) responded correctly that the desaturation was clinically important and identified an appropriate course of action (p = .0015).

Scenario number 2. This scenario involved a child with sickle cell anemia with a Hgb of 5 gm/dL. Respondents were asked what the implications of the oximetry reading were and what would be their immediate response.

Components of a correct response. The Pa[O.sub.2] has decreased from approximately 94 mm Hg to 90 mm Hg. The pulse oximeter does not reflect decreased oxygen carrying capacity secondary to a low Hgb. Anemic patients may not have adequate oxygen to meet metabolic demands even though their Hgb is saturated with oxygen and they have an acceptable Sa[O.sup.2]. This patient is becoming hypoxic. Appropriate courses of action include checking the airway, breathing, and circulation; increasing the oxygen flow rate; and notifying the physician.

Results. Only 7% of physicians and 14% of nurses identified the implication of the decreasing saturation with no statistically significant difference between the groups (p = .0191). Significantly more physicians were able to identify an appropriate course of action (27%), than nurses (14%; p < .0001).

Scenario number 3. This scenario involved a child with unrepaired Tetrology of Fallot who has an oxygen saturation of 85% when asleep and 80% when eating. Respondents were asked to provide their assessments, immediate actions, and any changes they would make to the plan of care.

Components of a correct response. The correct assessment is to note an increased oxygen demand during eating. Although the child's baseline saturation is expected to be low secondary to intracardiac right to left shunting, the child needs intervention during eating to prevent further hypoxia.

Results. Significantly more physicians (47%) than nurses (17%) assessed the situation correctly (p < .0001). A greater number of nurses (19%) than physicians (7%) would stop oral feedings, increase the oxygen flow rate, and either feed via a nasogastric tube or initiate small frequent feedings if the child was not tachypneic (p < .0001). Only one physician would change the plan of care by stopping oral feedings and ordering nasogastric feedings, and one physician identified these readings as normal for this diagnosis and would not take any immediate action but long-term plans would include surgery.

Scenario number 4. The final scenario involved a 4-month-old, with a history of an acute life-threatening event, who is admitted for evaluation of gastroesophageal reflux. Respondents were asked for their assessments, immediate responses, and any changes in the plan of care that they would initiate.

Components of a correct response. Practitioners should assess the child. Although the monitors do not correlate, this may be a real hypoxic event that has corrected itself as opposed to an artifact that caused the appearance of desaturation. Changes in plan of care are based on the assessment.

Results. Of the nurses, 52% correctly stated that they would check the child first and adjust the pulse oximeter since the two heart rates reported by the two monitors do not correlate; 13% of the physicians would do the same (p < .0001). The appropriate change in the plan of care would be to change the sensor site, which 24% of the nurses replied that they would do. Significantly fewer physicians reported that they would change the plan of care (p < .001). Two physicians assessed the situation as possible transient hypoxia and bradycardia secondary to reflux and would change the plan of care by ordering CXR, reflux precautions, and obtaining an UGI or pH probe to rule out reflux.

Discussion and Recommendations

Pediatric practitioners included in this survey expressed relatively high confidence in their knowledge related to pulse oximetry. However, the level of understanding by these practitioners was unacceptably low as reflected in their responses to survey questions.

Previous studies demonstrated marked lack of understanding of the oxyhemoglobin dissociation curve (OHDC), lack of knowledge of other technology, and inadequate interpretation of data leading to delayed interventions and changes in plans of care. The current study results support the previous studies' findings in understanding of the technology, its limitations, and application in the clinical setting. This is somewhat surprising considering the increased use of oximetry equipment in all health care settings since the time those earlier studies were conducted.

The results of this study indicate that overall pediatric staff surveyed were not consistently able to recognize the significance of low oximetry readings and did not consistently indicate an appropriate action. Physicians responded correctly more frequently than nurses or respiratory practitioners to 'theoretical questions,' such as the units of measure for Sa[O.sup.2] and Pa[O.sup.2], and the relationship between these (OHDC). Respiratory practitioners were more comfortable with the technology of the equipment. Nurses, however, were more likely to take action in the clinical scenarios and problem-solve to correct or prevent recurrence than physicians. This may be due to the direct care-giving role of bedside nurses.

Neither nurses nor physicians appreciated that small changes in saturations could result in significant sequelae. The clinical scenario of the child with sickle cell anemia would require integration of theoretical knowledge. Although anemia does not interfere with oximeter readings per se, it yields readings that are prone to misinterpretation by practitioners. Marked anemia would shift the OHDC to the left, resulting in smaller decreases in saturation corresponding to increasingly significant drops in Pa[O.sup.2].

Cote et al. (1991) point out that appreciable clinical signs and symptoms do not become evident until there is a significant hypoxic event. Clinical evidence of hypoxia is seen at mean SpO2 of 70 +/- 8%. Further, Cote and colleagues define a major hypoxic event to have occurred when the Sp[O.sup.2] is < 85% for more than 30 seconds. Identification of major hypoxic episodes would require oximetry equipment and strong clinical judgment of practitioners to correctly interpret the data.

This study showed that although there is wide exposure to the equipment, practitioners of all disciplines did not consistently have the knowledge needed to interpret data and make appropriate alterations in plans of care. The danger in this situation lies in the consequence of significant hypoxic episodes being under-recognized and under-treated despite sophisticated monitoring. As these findings and those of previous studies indicate, there is a definite need for increased and improved education about the proper use of pulse oximetry technology and interpretation of oximetry readings.


The full value of the addition of oximetry to monitor pediatric patients will not be realized until the knowledge level of all pediatric health care providers is improved. Formal and informal education programs need to be developed for all disciplines to specifically address oxygen saturation as a physiologic parameter in routine patient assessment. Educators in health care settings should validate practitioner knowledge during orientation. Mentors should confirm that practitioners are correctly interpreting oximetry data from actual patient situations. Additionally, annual review of critical decision-making could include oximetry as a high-risk, problem-prone skill using a clinical scenariobased approach.

The nationwide nursing shortage will result in less experienced nurses in the workforce, thus requiring greater vigilance in developing their knowledge. Nursing school curriculums need to integrate oximetry interpretation from course to course to solidify the theory and provide a basis for sound clinical judgment. This becomes crucial with the nursing shortage as increased use of unlicensed assistive personnel are relied upon for data collection. The analysis of these data and determination of appropriate interventions are still the responsibility of the licensed professional.

 Table 1. Demographic Data Survey  This study is designed to survey the knowledge base related to pulse oximetry technology and clinical interpretation of these data by resident physicians, nurses, and respiratory therapists and technicians.  Completion of this survey will be taken as consent to participate in this research.  Please complete the following information:  1. Position    a. RN--   b. LPN--   c. Respiratory Therapist--   d. Respiratory Therapy Technician--   e. First Year Pediatric House Staff--   f. Second Year Pediatric House Staff--   g. Third Year Pediatric House Staff--  2. Number of years of patient-related experience in your profession    a. Less than 6 months--   b. Less than 1 year--   c. 2-5 years--   d. 6-10 years--   e. Over 10 years--  3. How many years of experience have you had using pulse oximeters?    a. No experience--   b. Less than 6 months--   c. Less than 1 year--   d. 2-5 years--   e. 6-10 years--   f. Over 10 years--  4. Do you feel you have received adequate training in the use of pulse oximeters?    a. Yes--   b. No--  5. What kind of training have you had in the use of pulse oximeters? Check all that apply.    a. Lecture--   b. Self study (handout, module, video, etc.)--   c. Informal training during clinical practice--   d. Formal equipment inservice--   e. Other--  6. What is the highest degree or training level in your specialty?    a. LPN licensure--   b. Diploma in nursing--   c. Associate degree in nursing--   d. Baccalaureate degree in nursing--   e. Master's degree in nursing--   f. MD--   g. Associate degree in another field--   h. Baccalaureate degree in another field--   i. Other--  Table 2. Pulse Oximetry Knowledge Survey  1. Identify the designated parts of the pulse oximeter. See attached.  2. What does a pulse oximeter measure?  3. How does a pulse oximeter work?  4. How often do you document the reading from the pulse oximeter?  5. What is the normal range of oxygen saturation for an Adult? -- Child?    -- Infant? --  6. What is the unit of measure for:     a. Oxygen saturation (Sp[O.sub.2])?    b. Oxygen partial pressure (Pa[O.sub.2])?  7. What, if any, is the relationship between oxygen saturation and    partial pressure of oxygen?  8. What happens to the pulse oximeter reading of a patient     a. In cardiac arrest?    b. In respiratory arrest?    c. In shock?  9. Identify what effect, if any, the following factors have on the pulse oximetry reading:                                                      Falsely Factor                                 No Effect    Decrease  Nail polish Dark skinned race Jaundice Anemia Bright overhead lights or sunshine Carbon monoxide poisoning Cardiac dysrhythmias Peripheral vasoconstriction Cold environment                                                      May not be                                        Falsely      able to pick Factor                                 Increase     up signal  Nail polish Dark skinned race Jaundice Anemia Bright overhead lights or sunshine Carbon monoxide poisoning Cardiac dysrhythmias Peripheral vasoconstriction Cold environment  Clinical Scenarios:  1. A child is admitted with RSV. The oxygen saturation is 96% and HR    140. The oxygen saturation drops to 91%, with HR 155 on the    saturation monitor and 152 on the A/B monitor.     a. What are the implications of this oximetry reading?  2. A child with sickle cell disease is admitted wth a Hgb of 5. The    oxygen saturation drops from 98% to 95%. The heart rate is 140 on    the saturation monitor and 142 on the ECG monitor.     a. What are the implications of the oximetry reading?    b. What is your immediate response?  3. A child with unrepaired Tetrology of Fallot has an oxygen saturation    of 85% when asleep and 80% when eating.     a. What is your assessment of the situation?     b. What immediate action would you take?     c. What changes in the plan of care would you initiate?  4. A 4-month-old with a history of ALTE is admitted for evaluation of    GER. The central monitor at the nurses' station is alarming and reads    oxygen saturation of 58% and HR of 80. When you enter the room the    A/B monitor reads HR of 122 and RR of 30.     a. What is your assessment of the situation?     b. What immediate action would you take?     c. What changes in the plan of care would you initiate?  Please do not discuss your answers with anyone who has not yet completed the survey.  Table 3. Factors Affecting Accuracy of Pulse Oximetry Reading                         Correct         MD           RN      Factor            Answer       (N = 15)     (N = 42)  Life Threatening Cardiac              Inadequate        27%          17% arrest               signal Respiratory          Decrease          87%          77% arrest Shock                Inadequate        20%          12%                      signal  Physiologic Jaundice             I No change       53%          57% Anemia               No change         20%          14% CO Poisoning         Increase          40%          36% Dysrhythmia          Inadequate        20%          29%                      signal Dark skin            No change         87%          83% Peripheral           Inadequate        40%          55% vasoconstriction     signal  Environmental Nail polish          Inadequate        33%          31%                      signal Bright light         Increase          20%          17% or sunshine Cold                 Inadequate        40%          55% environment          signal                           RT      Factor            (N = 9)          P  Life Threatening Cardiac                  22%           NS arrest Respiratory              44%           NS arrest Shock                    22%           NS  Physiologic Jaundice                 44%           NS Anemia                   33%           NS CO Poisoning             44%           NS Dysrhythmia              11%           NS  Dark skin                56%           NS Peripheral               33%           NS vasoconstriction  Environmental Nail polish              22%           NS  Bright light             11%           NS or sunshine Cold                     52%           NS environment 


Cote, C.J., Rolf, N., Liu, L.M.P., Goudsouzian, N.G., Ryan, J.E, Zaslavsky, A., Gore, R., Todres, I.D., Fassallo, S., Polaner, D., & Alifimoff, J.K. (1991). A single-blind study of combined pulse oximetry and capnography in children. Anesthesiology, 74, 980-987.

Kruger, P.S., & Longden, RJ. (1997). A study of a hospital staff's knowledge of pulse oximetry. Anesthesia and Intensive Care, 25, 38-41.

Miller, P. (1992). Using pulse oximetry to make clinical nursing decisions. Orthopedic Nursing, 11(4), 39-42.

Murray, C.B., & Loughlin, G.M. (1995). Making the most of pulse oximetry. Contemporary Pediatrics, 12(7), 45-62.

Rodriguez, L.R., Kotin, N., Lowenthal, D., & Kattan, M. (1994). A study of pediatric house staff's knowledge of pulse oximetry. Pediatrics, 93, 810-813.

Stoneham, M.D., Saville, G.M., & Wilson, I.H. (1994). Knowledge about pulse oximetry among medical and nursing staff. Lancet, 344, 1339-1342.


Getting It Right: Appropriate Interpretations in Clinical Practice.

The purpose of this continuing education series is to increase the pediatric nurse's understanding of two interpretations common in pediatric settings: feeding tube placement and pulse oximetry readings.

In an information age, pediatric nurses may find it difficult to keep abreast of the latest research and technology, even about issues addressed everyday in many pediatric settings. In some instances, adherence to time-honored nursing practices presents a barrier to 'getting it right.' In other cases, it is a matter of having insufficient understanding of equipment or procedures before incorporating its use into everyday routines.

Nurses need to keep current regarding research and equipment affecting the populations they serve. Such knowledge will better enable nurses to make accurate interpretations and to respond appropriately.

This continuing education series features two articles related to interpretation. The first article discusses the literature regarding methods for determining correct feeding tube placement. The second article presents research findings of doctors, nurses, and other health care professionals' knowledge base related to pulse oximetry technology and clinical interpretation of data given.


Huffman, S., Pieper, R, Jarczyk, K., Beyne, A., & O'Brien, E. (2004). Methods to confirm feeding tube placement: Application of research in practice. Pediatric Nursing, 30(1), 10-13.

Popovich, D., Richiuso, N., & Danek, G. (2004). Pediatric health care providers' knowledge of pulse oximetry. Pediatric Nursing, 30(1), 14-20.


1. Which of the following is NOT a risk factor in children for improper placement or displacement of NG or NJ tubes?

a. Presence of artificial airway.

b. Decreased level of consciousness.

c. Inactivity.

d. Dysphagia.

e. 'Argyle' brand tube.

2. Which of the following methods is MOST accurate to verify proper NG tube position?

a. Checking appearance of aspirate.

b. Checking pH of aspirate.

c. Auscultation of insufflated air.

d. Radiograph.

e. Presence of bubbles when end of tube is held under water.

3. A pediatric RN is verifying placement of an NG tube on a 3-year-old boy who is comatose. She aspirates the tube and the material is clear with a pH of 7. The child is not on any acid blocking medications and has not been fed for 6 hours. The amount of external tube seems longer, and the tape is loose. Which of the following is the BEST next step?

a. Auscultate over the stomach and, if gurgling is heard, begin feeding.

b. Remove and replace the feeding tube and reassess for position.

c. Push the tube down a little and start feeding.

d. Retape the tube and start the feeding.

4. An NG tube aspirate pH of 6 could be the result of

a. recent or continuous feedings.

b. improper tube placement.

c. recent administration of an acid-blocking medication.

c. proper tube position.

e. all of the above.

5. An infant is being fed via NJ tube continuously and has been doing fine. Suddenly, he begins to vomit formula colored material. What is the MOST likely reason?

a. Formula intolerance.

b. Intestinal obstruction.

c. NJ tube has migrated back into the stomach.

d. 'Dumping syndrome.

e. None of the above.

6. What do pulse oximeters measure?

a. Pa[O.sup.2] partial pressure of oxygen.

b. Percent of oxygenated body surface area.

c. Percent of oxygenated hemoglobin.

d. TC[O.sup.2], transcutaneous partial pressure of oxygen.

e. PC[O.sup.2], partial pressure of carbon dioxide.

7. Under normal metabolic conditions an oxygen saturation of 90% corresponds to what Pa[O.sup.2]?

a. 90 mm Hg.

b. 60 mm Hg.

c. 85 mm Hg.

d. 75 mm Hg.

e. 50 mm Hg.

8. Which of the following affects the ability of a pulse oximeter to obtain a reading?

a. Dark skinned race.

b. Anemia.

c. Bright light.

d. Cardiac arrest.

e. Hypertension.

9. A child with epiglottitis is admitted with a Sp[O.sup.2] of 80% and a HR of 180. Oxygen via mask at 3L is administered. The Sp[O.sup.2] increases to 90%, HR remains at 180. What is your first response?

a. Airway management.

b. Saturation is acceptable; do nothing.

c. Increase oxygen to 4L via nasal cannula.

d. Obtain an arterial blood gas.

e. Check the leads on the pulse oximeter monitor.

10. An infant with bronchiolitis is receiving 500 cc of oxygen and the pulse oximeter reads Sp[O.sup.2] of 98% and a HR of 110. The Sp[O.sup.2] drops to 87%. The apnea/bradycardia monitor reads HR of 140 and RR of 60. What is your first response?

a. Obtain an arterial blood gas.

b. Increase the oxygen to 600 cc.

c. Check the leads on both monitors.

d. Stimulate the infant to increase the HR.

e. Leave the oxygen at 500 cc and notify the physician.


1. Discuss two interpretations commonly made in pediatric settings.

2. Describe a research-based method to confirm proper feeding tube placement.

3. List three basic principles of pulse oximetry.

4. Identify opportunities for pediatric nurses to keep current on knowledge that affects their area of practice.

This offering for 3.7 contact hours is provided by Anthony J. Jannetti, Inc., which is accredited as a provider of continuing education in nursing by the American Nurses Credentialing Center's Commission on Accreditation (ANCC-COA). Anthony J. Jannetti, Inc. is an approved provider of continuing education by the California Board of Registered Nursing, CEP No. 5387.

Articles accepted for publication in the continuing education series are refereed manuscripts that are reviewed in the standard Pediatric Nursing review process with other articles appearing in the journal.

This test was reviewed and edited by Judy A. Rollins, PhD, RN, Pediatric Nursing associate editor, Veronica D. Feeg, PhD, RN, FAAN, Pediatric Nursing editor, and Marion E. Broome, PhD, RN, FAAN, a Pediatric Nursing editorial board member.


1. Select the best answer and check the corresponding box on the answer form. Retain the test questions as your record.

2. Complete the information requested in the space provided.

3. Detach the answer form or a copy of the answer form and mail to: Pediatric Nursing, CE Series, Jannetti Publications Inc.; East Holly Avenue Box 56; Pitman, NJ 08071-0056 with a check or money order payable to Jannetti Publications Inc. for $10.00 (subscriber) or $15.00 (non-subscriber).

4. Test returns must be postmarked by February 20, 2006. If you pass the test (70% or better), a certificate for 3.7 contact hours will be awarded by Anthony J. Jannetti, Inc.

Please allow 4-6 weeks for processing. For recertification purposes, the date that contact hours are awarded will reflect the date of processing.

Debbie M. Popovich, MSN, CPNP, is Clinical Assistant Professor, at the University of Florida College of Nursing, Gainesville, FL.

Nancy Richiuso, MSN, RN, is Clinical Assistant Professor, at the University of Florida College of Nursing, Gainesville, FL.

Gale Danek, PhD, RN, is Quality and Regulatory Coordinator, at Shands Children's Hospital at the University of Florida, Gainesville, FL.