Cardio-respiratory polygraphy studies are performed to assess whether a patient has sleep disordered breathing. Sleep disordered breathing may be obstructive or central in nature, or there may be a mixed picture. Cardio-respiratory polygraphy studies and also to monitor the effectiveness of interventions such as ventilation.

This protocol is for cardio-respiratory polygraphy using the following sensors:
• Pulse oximeter
• Transcutaneous CO2
• ECG
• Nasal flow pressure transducer
• Thoracic effort band
• Abdominal effort band
• Position sensor

Setting Up an In-patient On-Line Study
SOMNOBox
• Put a fully charged battery into the SOMNOBox for the study.
• When conducting an on-line study the SOMNObox needs to be connected to the laptop. There are 2 different systems for this, one is wired , the other is wireless.
• For the wired system, plug the USB lead into the laptop and connect it to the grey and white connector box. Then connect the grey and white connector box to the blue SOMNObox with the ‘telephone wire’ connection.
• For the wireless connection the blue transmitter box needs to be plugged into the blue SOMNObox and then the black receiver box with the aerial needs to be connected to the laptop via the grey serial port cable and the serial port USB converter. The black receiver box also needs to be connected to the mains.
• When setting up the study, if the laptop does not pick up a signal try changing the USB port and initializing again.

Laptop
• Switch on the SOMNObox by pushing in the second ‘O’ of the word SOMNO.
• Open the DOMINO panel on the laptop and select ‘On-line study’.
• Enter patient data
• click ‘next’.
• Ensure ‘Paed PSG TOSCA (17)’ is selected and ‘On-line mode’ is selected,
• click ‘next’
• Select ‘Auto start’, and then input start date and time. (if this is greyed out, make sure the SOMNO box is switched on or change the USB port if using the wireless system)
• Click OK
• The live screen should now come up but with no traces.

For overnight nursing staff on the ward
• Everything up this point will be set up by the sleep physiologist or respiratory nurse and brought to the ward.
• When you are ready to start up the study, place patient sensors on and after the selected start time has passed the sleep study waveforms should appear on the screen,
• You need to click ‘start recording’ to record the study.
• Check all sensors are recording.
• During the night regularly check the waveforms and document that they are functioning on the supplied paperwork. If any signal is lost  check/adjust cables and bands and connections.
• In the morning stop the recording by selecting ‘Stop Online Mode’ from the ‘File’ menu and then confirm all warning messages. Do not turn off the blue SOMNObox.

Sensor Application – the diagragm below should help in positioning sensors correctly

ECG
The ECG electrodes need to be stuck onto the chest as shown in the diagram. Then the lead needs to be plugged into the yellow slot marked EXG.
Chest Band
The chest band fastens firmly around the chest in line with the nipples using the velcro.
Connect the band to the SOMNObox by clipping the leads onto the 2 ‘snap’ connectors and plug into the orange slot labeled AKT.
Abdominal Band
Make sure you have the correct band size for the patient: (Grey – Extra small, Red – Small. blue – Medium, Black – Large,Yellow – Extra large)
The abdominal band fastens firmly around the stomach inline with the navel. Sizes are as above. Connect to SOMNO box in the same way as chest band and plug into the dark green slot labeled ABDO.
Position sensor
The position sensor is applied to the front of the chest band using velco. It is important to ensure it is the correct way up and in the centre of the chest. Plug into the blue SOMNO box slot marked PLM1.
Oxygen Saturation Probe
The oxygen saturation probe fastens securely to the finger or toe over the nail bed. Plug into the red SOMNO box marked SpO2.
Nasal Cannula
Connect the nasal cannula via luer lock to the pressure interface on the CPAP sensor. Then connect the black coloured plug to the socket on the SOMNOscreen box marked CPAP. Lastly fit the nasal cannula sensor to the patient’s face with the prongs sitting just under the nostrils and secure with the sliding attachment. Tape can also be used across the cheeks to keep in place.
TOSCA
• The TOSCA must be plugged in to the mains power at all times.
• The scart lead and separate power plug connects to the back of the TOSCA and then another lead connects this box to the SOMNObox into the light green slot labeled AUX.
• The TOSCA should display on the front screen that it is ‘READY TO USE’.
• The ear clip should be used for older children (usually over 7 years) and the white chest stickers for younger children (under 7 years).
• To use the ear clip, remove packaging and peel off the white paper revealing a sticky area. Attach the ear clip to the earlobe (take care to avoid any piercing holes if possible), gently squeeze and hold in place for about 20 seconds to secure position.
• Remove the black sensor from the ‘autocal’ slot. Place one drop of the contact gel onto the sensor and clip the sensor onto the ear clip.
• If using the chest ring sticker, place it on the chest under the collar bone and then connect the sensor with contact gel in the same way.
• It takes approximately 10 minutes for the TOSCA to warm the site up enough for the CO2 reading to accurate, after 10 minutes has passed, if the PCO2 value is less than 2.5Kpa it suggests that the sensor has not been applied properly. In this case unclip the sensor, wipe off the contact gel with a dry cloth and put it back into the ‘auto cal’ slot until it reads ‘READY TO USE’ again. When it is ready start the process again using a new ear clip or ring. This same method should be used if the sensor comes off in the night.

Overnight monitoring
• The sleep study nurse is responsible for applying the sensors and setting up the patient for the sleep study, regular checking of the signal quality and adjusting the sensors accordingly.
• As well as completing the observation chart it is important that the sleep study nurse makes note of any other events they feel are relevant such as snoring and desaturations (duration, and lowest level).
• Accurate documentation of information from the sleep study is paramount as this is important for the sleep physiologist analysing the study. It is important to document if the patient had any ventilation or oxygen overnight, which settings they were on and the time these were used.

Setting up a home study
• Initialise Flash Card
• Switch on lap top and plug in USB card reader.
• Insert smart card into reader.
• Open the “DOMINO panel” and click the ‘initialize’ button.
• Enter the patients data.
• Click ‘next’.
• Ensure ‘manual start’ is selected with a duration of 12hrs.
• Click ‘next’.
• Ensure ‘Paed PSG TOSCA (17)’ is high-lighted and DE-SELECT ‘online mode’.
• Click ‘Initialise Flash Card’
• When it has formatted, safely remove the flash card and place it back in the SOMNO box for the study.
• Put a fully charged battery into SOMNOBox for the study.

When sensors are in place:
• Turn the power on the SOMNOBox by pushing in the second ‘O’ of the word SOMNO on the sleep box and hold it in until the screen lights up with a ‘flashing marker’.
• Press the red arrow under the screen 4 times allowing the screen to change each time you press. This will scroll through pre test checks and then finally starts the recording.
• When the recording has started there should be real time recordings for % SpO2 and pulse rate on the screen. It will record for 12 hrs and then automatically turn off.
• If the child wakes up before the screen has turned off, just remove leads – DO NOT switch off the box before it has finished and DO NOT remove the smart card as this will DELETE the sleep study.
• If you do need to stop the sleep study early and it is not possible to just ‘let it run’ press all three buttons on the front together and hold down for a few seconds, then select ‘cancel’ (using arrows and confirm using the enter button) and then confirm ‘sure’ in the same way. The recording will now be stopped.

Downloading a study
• Remove the flashcard from the SOMNO box and insert it into the card reader. Open the DOMINO panel and select ‘Download’. Check the patient details are correct and then click ‘download’.
• When the study has downloaded, open the SOMNO panel and select ‘Analyse’, open the study which has just been downloaded and then in put details of the study e.g. ventilation settings used etc. in the Tools menu and then patient info.

Trouble shooting
TOSCA
• If the TOSCA probe comes off during the study, wipe the probe with a dry cloth and put it in the ‘autocal’ slot for calibration. Only place the probe on the patient when the screen displays ‘READY TO USE’.
• If the screen displays ‘Too Much Ambient Light’ the ear clip needs repositioning.
• If the screen reads ‘Movement Artifact’ this simply means the patient is moving and once they settle this message should go.
• If the screen is requesting ‘Renew Gas Bottle’ continue overnight monitoring and inform the Respiratory Nurse or Sleep Physiologist the following day.
• If the screen displays ‘Remembrane Sensor’, follow these steps:
• Press the DOWN ARROW once and the word MENU should be highlighted.
• Then press the + key
• Press the DOWN ARROW until PCO2 PARAMETERS is highlighted.
• Then press the + key
• Continue to press the DOWN ARROW 3 times until SPECIAL PCO2 PARAMETERS is highlighted
• Then press the + key
• Continue to press the DOWN ARROW a further 5 times until SENSOR REMEMBRANED? +YES+ Is highlighted.
• Then press the + key and the machine will record as normal
• If this procedure had to be followed please inform the Respiratory Nurse or Sleep Physiologist the following day.

Other Signals
• If any other signals fail, check connections and adjust sensors.
• If bands fail make sure they are tight enough but do not cause discomfort, if there is still no signal try another size or spare band and report it on the observation chart.