Clinical Use Guide
60 Pages
Preview
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Fetal Pulse Oximetry System Clinical Use Guide
Use this manual with software version 4.6
Nellcor Puritan Bennett Inc. is an affiliate of Tyco Healthcare. Nellcor and OxiFirst are trademarks of Nellcor Puritan Bennett. To obtain information about a warranty, if any, contact Nellcor’s Technical Services Department or your local representative. Purchase of this instrument confers no express or implied license under any Nellcor patent to use the instrument with any sensor that is not manufactured or licensed by Nellcor. Covered by one or more of the following U.S. Patents and foreign equivalents: 4,621,643; 4,700,708; 5,228,440; 5,247,932; 5,377,675; 5,421,329; 5,660,567; 5,782,237; 5,743,260; and Des. 384,643.
Contents
Warnings, Precautions, and System Information... 1 Intended Use/Indications ...1 Contraindications ...1 Warnings ...2 Precautions ...3 Clinical Use Precautions ...4 Technical Precautions ...5 Alarms ...6 Inaccurate Measurements ...7 Loss of Pulse Signal ...7
Placement Criteria and Patient Management... 9 Introduction ...9 Sensor Placement Criteria ...9 Patient Management ...11 Fetal Heart Rate Classification ...11 Clinical Management Protocol ...13 Fetal Evaluation Protocol ...14
Control Buttons, Status Indicators, and System Components . . 17 Front Panel ...17 Description of Front Panel ...18 Rear Panel ...19 Description of Rear Panel ...20 Fetal Patient Module ...21 Nellcor Fetal Oximetry Sensor ...21
Guide to Operation... 23 FHR and Optical Pulse Rate Determination ...23 Fetal Heart Rate Measurement ...23 Optical Pulse Rate Determination ...23 i
Contents
Typical Setup ... 24 Turning on the N-400 ... 24 Power-Up and Self-Test ... 25 System Operation Overview ... 26
Preparation for Sensor Placement... 27 Preparing for Placement ... 27
Sensor Placement and Adjustment... 29 Overview ... 29 Pulse Tone Feature ... 30 Using Pulse Tone ... 30 Placing the Sensor ... 31 Adjusting and Optimizing Sensor Placement ... 36 Maintaining Optimal Sensor Position ... 38
Troubleshooting Guide... 39 Overview ... 39 Potential Problems and Resolutions ... 39
Appendices... 47 Overview ... 47 Appendix A ... 48 Appendix B ... 49
Index 51
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OxiFirst System Clinical Use Guide
Contents
Figures Figure 1: Figure 2: Figure 3: Figure 4: Figure 5: Figure 6: Figure 7: Figure 8: Figure 9: Figure 10: Figure 11: Figure 12:
Fetal Evaluation Protocol ...15 Front Panel ...17 Rear Panel ...19 Fetal Patient Module ...21 Nellcor Fetal Oximetry Sensor ...21 Typical OxiFirst System Setup ...24 Pelvic Station Using Top of Presenting Part ...28 Ideal Sensor Placement Site ...28 Left Occipitoanterior Position ...32 Right Occipitotransverse Position ...32 Introducing the Sensor ...32 Insertion to the Tactile Ridge ...33
Table 1: Table 2:
Fetal Heart Rate Classification... 12 Clinical Management Protocol Matrix... 13
Ta b l e s
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Wa r n i n g s , P r e c a u t i o n s , a n d S y s t e m Information
Carefully read this manual, the Information for Prescribers, the N-400 Operator’s Manual, accessory directions for use, all warnings, precautions, and specifications before application and use of the OxiFirst System.
Intended Use/ Indications
The OxiFirst Fetal Pulse Oximetry System continuously monitors intrapartum fetal oxygen saturation (FSpO2). Use of the OxiFirst System is indicated as an adjunct to fetal heart rate monitoring in the presence of a nonreassuring fetal heart rate pattern. It should only be used after amniotic membranes have ruptured, and on a singleton fetus in vertex presentation with a gestational age greater than or equal to 36 weeks. Fetus should be at or below -2 station.
Contraindications
Use of the OxiFirst Fetal Pulse Oximetry System is contraindicated in patients with one or more of the following conditions: • documented or suspected placenta previa • ominous fetal heart rate (FHR) pattern requiring immediate intervention • need for immediate delivery (unrelated to FHR pattern), such as active uterine bleeding
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Warnings, Precautions, and System Information
Warnings
Warnings in this manual are identified by the WARNING symbol shown above. A warning alerts you to potentially serious outcomes (death, injury, or adverse events) to the user or the patient. WARNING: The OxiFirst System is intended as an adjunct to fetal heart rate monitoring in fetuses with a nonreassuring heart rate pattern. It must be used in conjunction with clinical signs and symptoms. WARNING: Locate the monitor near the patient in a position that ensures it cannot accidentally fall on the patient. Failure to do so could result in patient injury. WARNING: The OxiFirst System should not be used while using an Electrosurgical Unit (ESU). Remove the fetal oximetry sensor from the mother and fetus before using an ESU. An improperly grounded ESU can cause surface skin burns on the fetus if both the OxiFirst System and an ESU are used together. WARNING: The OxiFirst System should not be used in the presence of flammable anesthetics. Such use may constitute a fire or explosion hazard. WARNING: The OxiFirst System should not be used to monitor patients during water births, in whirlpool or submersion water baths, during showers, or in any other situation where the mother is immersed in water. Doing so may result in electrical shock hazard.
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OxiFirst System Clinical Use Guide
Warnings, Precautions, and System Information
WARNING: Do not use the N-400 monitor or fetal oximetry sensor during magnetic resonance imaging (MRI) scanning. Induced current may potentially cause burns or erroneous FSpO2 measurements. WARNING: The OxiFirst System should not be used in women with active genital herpes or other infection precluding internal monitoring. Insertion of the fetal oximetry sensor in these women may result in transmission of pathogens to the fetus. WARNING: The OxiFirst System should not be used in women who are seropositive for human immunodeficiency virus (HIV). Insertion of the fetal oximetry sensor in these patients may result in fetal exposure to the virus. WARNING: Intrauterine insertion of the fetal oximetry sensor in women who are seropositive for Hepatitis B and/or Hepatitis E antigens may result in fetal exposure to these antigens.
Precautions
Precautions are identified by the CAUTION symbol shown above. A caution alerts you to exercise care necessary for the safe and effective use of the OxiFirst system.
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Warnings, Precautions, and System Information
Clinical Use Precautions Caution: Physicians and other licensed practitioners who use the OxiFirst System should have demonstrated expertise in determining fetal presentation and head position, and should be proficient in the placement of fetal scalp electrodes and intrauterine pressure catheters. Caution: Do not attempt to insert the sensor if patient is dilated less than 2 cm or if amniotic membranes have not completely ruptured. Doing so may result in erroneous FSpO2 measurements and/or patient injury. Caution: Do not attempt to rupture amniotic membranes with the sensor. Doing so may result in patient injury and/or sensor malfunction. Caution: In situations where an FSpO2 value is not present, and efforts to readjust the sensor fail to restore the displayed value, clinical management should be based on available data; e.g., FHR. No inferences regarding fetal status should be made on the basis of earlier FSpO2 values. Caution: Do not leave the fetal oximetry sensor in place during vacuum extraction, forceps delivery or cesarean delivery. Doing so may result in patient injury. Remove the fetal oximetry sensor before commencing any form of operative delivery. Caution: Application of the Nellcor® Fetal Oximetry Sensor may cause temporary skin indentations, markings, or bruising on the fetus at the sensor site. Caution: If the fetal heart rate slows during vaginal exam or sensor insertion, stop the procedure. Do not proceed with sensor placement as this can cause a reflex bradycardia stimulus. Wait for the fetal heart rate to return to the previous range before proceeding.
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OxiFirst System Clinical Use Guide
Warnings, Precautions, and System Information
Technical Precautions Caution: Suboptimal sensor placement, excessive vernix, fetal hair or motion artifact due to uterine contractions or maternal position changes may result in no FSpO2 values being displayed, or erroneous FSpO2 measurements. Caution: The fetal oximetry sensor may be left in place during defibrillation but FSpO2 readings may be inaccurate for a short time. Caution: Do not attempt to use any sensor other than a sterile, single-use Nellcor Fetal Oximetry Sensor with the OxiFirst System. Use of any other Nellcor oximetry sensor or any sensor from another manufacturer may result in system malfunction, erroneous FSpO2 readings, and/or patient injury. Caution: When placing the Nellcor Fetal Oximetry Sensor, exercise caution to avoid interference with other internal probes, such as an intrauterine pressure catheter or a fetal scalp electrode. Caution: Do not use a damaged sensor. Doing so may result in patient injury, sensor malfunction, and/or erroneous FSpO2 measurements. Caution: Do not use the N-400 monitor if the outside monitor cover or front or rear panels appear to be damaged. Doing so may result in patient injury, instrument malfunction, and/or erroneous FSpO2 measurements. Caution: Never attempt to clean, reprocess, resterilize, or reuse fetal oximetry sensors. Doing so may result in sensor malfunction, erroneous FSpO2 measurements, and/or infection or potential tissue injury to mother and/or fetus. Each fetal oximetry sensor is supplied as a sterile, singleuse, disposable device. Caution: Do not remove the outside monitor cover. Doing so may result in electrical shock hazard. There are no userserviceable parts inside.
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Warnings, Precautions, and System Information
Caution: Replace instrument fuses only with those of the same type and rating to protect against fire hazard. Caution: Do not immerse the sensor completely in liquid-the connector is not waterproof. Immersion of the sensor plug in liquid may result in sensor malfunction and/or erroneous FSpO2 measurements. Caution: Do not immerse the Fetal Patient Module completely in liquid– the unit is not waterproof. Fluid damage to the module may result in malfunction and/or erroneous FSpO2 measurements. Caution: Do not reinsert a stylet into the sensor stylet chamber after it has been completely removed. Doing so may result in maternal injury. Most sensor adjustments can be accomplished without the stylet being reinserted into the sensor. Caution: Do not connect Nellcor sensor extension cables, such as the EC-4 or EC-8, to the OxiFirst System. Unreliable readings may result due to excessive electrical interference. Caution: For optimal clarity of audible indications and alarms, ensure that the speaker is clear of any obstruction.
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OxiFirst System Clinical Use Guide
Warnings, Precautions, and System Information
Alarms
The default state of the audio alarms is OFF. If audio alarms are to be used, they must first be enabled. If audio alarms are enabled, do not set the alarm volume too low to be heard. When the AUDIO ALARM OFF indicator is illuminated, no audio alarm sounds.
Inaccurate Measurements
Inaccurate measurements may be caused by: • incorrect application or use of a sensor • significant levels of dysfunctional hemoglobin, such as carboxyhemoglobin or methemoglobin • excessive fetal or maternal patient movement • venous pulsation Note: The user must independently verify that the N-400 pulse rate displayed is the actual fetal heart rate. This can be done by auscultation or by comparing to an independent FHR monitoring device.
Loss of Pulse Signal
Loss of pulse signal can occur: • during uterine contractions • if the fetus experiences shock, hypotension, severe vasoconstriction, severe anemia, arterial occlusion proximal to the sensor, or cardiac arrest
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Placement Criteria and Patient Management
Introduction
The Clinical Use Guide is intended as a guide for the use of the OxiFirst System in the Labor and Delivery department. This guide introduces the user to the criteria for sensor placement, the management of patients who have the fetal oximetry sensor in place, the proper method of preparing the system, placement of the sensor, and interpreting the front panel symbols on the N-400 monitor. In addition, this guide provides suggestions for troubleshooting various problems that may be encountered during use of this device. This guide is accompanied by the Information for Prescribers, which describes the randomized clinical trial performed to support the use of this device during labor. The guidelines listed below (Sensor Placement Criteria and Patient Management) are the guidelines that were used in the randomized clinical trial, with the addition of two FHR patterns to the ominous category (markedly decreased or absent variability with either persistent late decelerations or severe variable decelerations). The decision to utilize the OxiFirst System in the management of a labor requires judgement on the part of the clinician, and should be made in conjunction with all available clinical signs and symptoms. In no case should clinical management be guided by the oxygen saturation alone.
Sensor Placement Criteria
The patient should be in active labor (dilation ≥ 2 cm, vertex -2 station or lower) with completely ruptured membranes. The placement of the Nellcor Fetal Oximetry Sensor is indicated if the fetal heart rate (FHR) tracing shows evidence of one or more of the following nonreassuring FHR patterns. • baseline FHR between 100-110 with no accelerations > 15 bpm for more than 15 seconds • baseline FHR < 100 bpm with accelerations
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Placement Criteria and Patient Management
• increased variability > 25 bpm for more than 30 minutes • mild or moderate variable decelerations for more than 30 minutes • late decelerations (at least one per 30 minutes) • decreased variability < 5 bpm for more than 30 minutes • persistent late decelerations (> 50% of contractions) for more than 15 minutes • sinusoidal pattern for more than 15 minutes • variable decelerations with any of the following for more than 15 minutes: – a relative drop of ≥ 70 bpm or an absolute drop to ≤ 70 bpm for more than 60 seconds – persistent slow return to baseline – long term variability < 5 bpm – tachycardia > 160 bpm • recurrent prolonged decelerations (2 or more < 70 bpm for more than 90 seconds in 15 minutes) • tachycardia > 160 bpm with long term variability < 5 bpm for more than 60 minutes It is important to understand that the fetus may have suffered a period of hypoxia or ischemia prior to the establishment of fetal oxygen monitoring and may have developed a fixed metabolic acidosis as a result of prior events. If the condition leading to the prior hypoxia has resolved, subsequent fetal oximetry measurements may be normal, despite the fact that the fetus is still acidotic. Severe acidosis is likely to profoundly effect the FHR pattern and result in an ominous FHR tracing. Therefore, if the fetal heart rate pattern is ominous, as described below, the clinician should not delay prompt evaluation and/or intervention. Ominous FHR patterns include, but are not limited to: • prolonged deceleration to < 70 bpm for more than 7 minutes • markedly decreased or absent variability with persistent late decelerations, or
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OxiFirst System Clinical Use Guide
Placement Criteria and Patient Management
• markedly decreased or absent variability with severe variable decelerations. An ominous pattern which cannot be reversed by non-operative interventions (oxygen, fluid, repositioning, etc.) generally requires immediate operative delivery without further delay. Fetal oxygen saturation is neither a direct measure of fetal acidosis nor a direct indicator or predictor of fetal pH. Fetal oximetry measures real-time fetal oxygen levels only, limited to interpretation at the time of the reading.
Patient Management
Using the guidelines modified from the US Randomized Clinical Trial, patients may be managed according to a protocol guided by the combination of FHR classification and fetal oxygen saturation data. The FHR classification criteria used in the protocol are described in Table 1, and the clinical management protocol is described in Table 2.
Fetal Heart Rate Classification
FHR tracings are characterized according to the values of the baseline heart rate, the presence or absence of variability and accelerations, and the presence or absence of decelerations.
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Placement Criteria and Patient Management
Table 1: Fetal Heart Rate Classification FHR Class
FHR Pattern
I
REASSURING Any FHR pattern that does not meet criteria for Class II or III. Typically, a Class I trace is characterized by a baseline between 110 and 160 bpm, with long-term variability between 5 and 25 bpm, and either no decelerations or only early decelerations. NONREASSURING Any one of the following for more than 15 minutes:
• Persistent late decelerations ( > 50% of contractions) • Sinusoidal pattern a • Variable decelerations with one or more of the following: – A relative drop of ≥ 70 bpm or an absolute drop
II
to ≤ 70 bpm for more than 60 seconds b – Persistent slow return to baseline – Long term variability < 5 bpm c – Tachycardia > 160 bpm • Recurrent prolonged decelerations (2 or more < 70 bpm for more than 90 seconds) Any one of the following for more than 60 minutes:
• Tachycardia >160 bpm with long-term variability < 5 bpm c • Persistent decreased variability ( ≤ 5 bpm for more than 60 minutes) c OMINOUS
III
• Prolonged deceleration to < 70 bpm for more than 7 minutesd • Markedly decreased or absent variability with persistent late decelerations • Markedly decreased or absent variability with severe variable decelerations
a. Sinusoidal pattern is defined as regular oscillations about the baseline, 5-15 bpm in magnitude, with 2 to 5 cycles per minute on an otherwise normal baseline with absent short-term variability. b. Variable decelerations are to be timed from the beginning of the deceleration to the end of the deceleration (i.e., more than 60 seconds in duration).
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OxiFirst System Clinical Use Guide
Placement Criteria and Patient Management c. Decreased variability not otherwise explained by the clinical situation (e.g., narcotic administration). d. It is not necessary to wait for more than 7 minutes of prolonged deceleration before initiating intervention (e.g, evaluation of the cause, non-surgical intervention, and preparation for delivery), even with reasssuring FSpO2.
Clinical Management Protocol
The clinical management protocol is guided by the combination of FHR and FSpO2, and is given in the right three columns of Table 2 according to the intersection of the FHR tracing (row) and the FSpO2 condition (column).
Table 2: Clinical Management Protocol Matrix FHR Classification Group
FHR and Oximeter FSpO2 Not Reassuring a
FSpO2 Not Available Despite Sensor Adjustment
FSpO2 Reassuring b
Class I – Reassuring FHR Pattern
Continue labor unless
Continue labor unless
otherwise indicated c
otherwise indicated
c
Continue labor unless otherwise indicated
Class II – Nonreassuring FHR Pattern
Evaluate and manage nonreassuring
Evaluate and manage nonreassuring
FHR c
FHR c
Class III – Ominous FHR Pattern
Deliver
Deliver
a. b. c.
Continue labor unless otherwise indicated c
Deliver
FSpO2 Not Reassuring = FSpO2 remains below 30% between contractions, or no value displayed, despite sensor adjustment. FSpO2 Reassuring = FSpO2 returns to a value ≥ 30% between contractions. All corrective, non-operative interventions should be applied as described in Fetal Evaluation Protocol (pages 14-15).
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Placement Criteria and Patient Management
Fetal Evaluation Protocol
When the action called for in Table 2 is “Evaluate and manage nonreassuring FHR,” or in any situation in which the clinician is concerned about a non-reassuring FHR tracing, even in the presence of a reassuring FSpO2, the clinician should execute a series of escalating maneuvers intended to improve fetal oxygenation in an attempt to correct the condition(s) which triggered the abnormal state. These maneuvers may include: • maternal repositioning to achieve uterine displacement • hydration • correct hypotension • tocolytic for hypertonic contractions • maternal oxygen • amnio-infusion • assessment and correction of oxytocin drug dose If no FSpO2 value is being displayed, the clinician should reevaluate fetal position and adjust the sensor in an attempt to optimize placement. If adjusting the sensor fails to reestablish FSpO2 readings, the patient should be managed according to the fetal heart rate pattern alone. If operative intervention would have been chosen by the clinician had pulse oximetry not been utilized, then that operative intervention is the appropriate course of action. If these maneuvers correct the indication for an intervention, the action listed corresponding to the corrected conditions determines the intervention level. Thus, if the protocol matrix (Table 2) indicates “Deliver for fetal distress,” but the maneuvers taken by the bedside clinician correct the FHR and/or FSpO2 such that the indicated action changes to “Continue labor unless otherwise indicated,” the appropriate action becomes “Continue labor unless otherwise indicated.” If, following corrective maneuvers, the protocol matrix still indicates “Deliver for fetal distress,” the fetus should be delivered as soon as practical by whatever means judged appropriate.
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OxiFirst System Clinical Use Guide
Placement Criteria and Patient Management
If, following corrective maneuvers, the protocol matrix still indicates “Evaluate and manage nonreassuring FHR,” the clinician should use the evaluation protocol described in Figure 1 below to obtain additional information regarding fetal well-being. In addition, any of the above non-operative maneuvers are allowed when the status is “Continue labor unless otherwise indicated.”
Apply Corrective Interventions as Appropriate • Change position • Hydration • Tocolytics
• Correct hypotension • Assess/correct oxytocins • Supplemental Oxygen • Amnio-infusion
Figure 1: Fetal Evaluation Protocol
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Control Buttons, Status Indicators, and System Components
Front Panel 1
2
3 4
5
6
8
7
9
N-400
FSpO2%
?
min
2 SpO2
t
21
20 19 18 17
16 15 14
13 12
11 10
20
Figure 2: Front Panel 1
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Sensor Unplugged indicator
2 3
Fetal Patient Module connector ON/STANDBY switch Searching indicator
13 14
4 5 6 7 8
FSpO2 display Pulse Amplitude indicator Pulse Rate (bpm) display No function Signal quality indicator
15 16 17 18 19
9 10 11
Control knob Audio Alarm Off indicator Sensor lifted indicator
20 21
Audio alarm off button Low Saturation Alarm limit button Pull-out card slot No function No function Response Time button Mode 2 Response Time indicator Adjustable feet Attention symbol
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