You Are Here: Deltex Medical > Training & Support
Training & Support

The Deltex Medical Clinical Team possesses a wealth of experience in haemodynamic optimisation and Enhanced Recovery protocols. We are here to help you to get the most out of our powerful system and achieve the outcomes that Oesophageal Doppler Monitoring using the Deltex ODM and ODM+ systems has been proven to deliver.

A range of training options is available for the use of ODM+, from initial use of the product to advanced haemodynamic applications, including:

The Deltex Medical team of Clinical and Product Specialists delivers customised clinical support and educational programmes in both the ICU and surgical settings.

Classroom sessions are available for clinicians who will be users of the ODM or ODM+. The duration and content can be set according to specific needs and may include: cardiac anatomy and physiology, overview of the technology, clinical evidence, the need for fluid management and more.

Hands-on support in the clinical setting can also be arranged to follow on from classroom sessions or can also be arranged independently.

Please contact Deltex Medical or your local Training Team to discuss requirements.

The Deltex Medical Oesophageal Doppler Simulator (ODS) enables clinicians to practice probe insertion, focusing and waveform interpretation outside of a patient setting. It is designed for use with the CardioQ-ODM+.

  • Nasal and oral insertion practice
  • Recognition and location of descending aortic waveform
  • Simulates Pulmonary Artery, Coeliac Axis and Intracardiac waveforms
  • Capability to modify the waveform to simulate hypovolaemia
  • Key pad enables modification of descending aortic waveform

Accessories included with initial purchase:

  • simulator test probes
  • ultrasonic gel
  • syringe (for gel insertion)
  • bespoke roller case
  • instructions for use

For further information, please contact our Customer Services Department: +44 (0)1243 774 837 or email:  customer.services@deltexmedical.com quoting part code 9066-7001

 ODS LOGO

ODM+ monitoring uses Doppler ultrasound technology to determine directly a patient’s central vascular blood flow and fluid status during the intraoperative period. A probe is placed into the oesophagus, either orally or nasally and is similar to placing a nasogastric tube.

Easy to use and quick to focus, the device generates a low frequency ultrasound signal which is highly sensitive to changes in flow and measures them immediately.

Once in position the clinician is able to measure real time blood velocities within the descending aorta.

For more information, visit Deltex e-Learning or access the Training Workbook for a deeper understanding of how to use this technology.

Inserting the Probe Orally

Inserting the Probe Nasally

Instructions for use:

The probe can be used nasally in sedated, anaesthetised, awake and waking adult patients.

It should not be used nasally in paediatric patients.

  • Lubricate tip of probe with plenty of water-based gel. Do not use oil-based products.
  • Insert nasally into the oesophagus via nose and then the oropharynx. The technique is similar to that of placing a nasogastric tube into the oesophagus.
  • Do not use force.
  • Having the tip of the probe in the direction of the top of the head may aid insertion into and around the oropharynx.
  • In awake patients, the nasal mucosa may be anaesthetised if required and the posterior oropharynx can be sprayed with aerosol-based local anesthetic. Refer to local polices for further reference.
  • Having the patient swallow water may aid the movement of the probe down the oesophagus.
  • If necessary, small amounts of sedation may useful for increasing patient tolerance.

There are 3 depth markers on the adult probe. They are set at 35, 40 and 45cm from the tip. Using these depth markers and assessing the signal, will ensure the tip of the probe is at approximately T5/T6 area of the descending aorta. This is the region where the oesophagus and descending aorta will be closest.

For nasal use, the external nares in an adult should be between maker 2 and 3. It may be acceptable for them to be just outside of these markers by approximately 1 or 2 cm if the patient is particularly short or tall. Also consider the length of the torso if a signal cannot be found. Start at the deepest maker to find the optimal focus.

It can be used together with a nasogastric tube, a temperature probe or even a transoesophageal echocardiogram (TOE) probe.

ODM probes have been used successfully with an LMA. It may be helpful to place the probe before the LMA is placed. Ensure the seal of the LMA is lubricated well and when inflated, it should easily accommodate the probe.

Considerations:
  • Abnormalities or surgery of the mouth, pharynx, aorta and oesophagus.
  • Base of skull fractures.
  • Coagulopathies.
  • Remove probe if patient having an MRI.
  • Remove probe or disconnect if cardioversion required.
The following may make locating an optimal signal difficult:
  • Coartation of the aorta.
  • Use of intra aortic balloon pump.
  • Anatomical abnormalities.
  • Securing the probe
Securing the probe:
  • Many users do not secure the probe since peristalsis in the oesophagus may cause the probe to move internally.
  • If the user wishes to secure the probe with tape or a nasal clip, then ensure the probe can be manipulated to check focus.

 Focusing the Probe

How to get the optimal focus
  • It is useful to place the probe as early as possible for instance immediately after intubation so that a settling in period can be achieved where the probe sits comfortably against the oesophageal wall and the patient’s secretions will aid signal acquisition.
  • Insert the probe to deepest marker of where it was placed, i.e. 3rd marker if placed nasally, 2nd marker if placed orally to start with in an adult.
  • Turn up the sound on the monitor.
  • Choose this depth and rotate slowly all way round without letting go.
  • If no signal is seen at this depth, pull out slightly (by approximately 1 cm at a time) and rotate again slowly without letting go.
  • Repeat these changes of depth followed by rotations until a signal is found.
  • Do not pull and rotate at the same time as this will cause a spiral effect and the appropriate area may be missed.
  • Ensure the edge of the nose or the incisors is as near to the appropriate depth markers. If the patient is very tall or very short, it might be acceptable for the depth markers to be outside of nose or incisors by a small amount.
The qualities of a good signal:
  • The loudest, sharpest ‘whipcrack’ sound
  • The tallest waveform
  • The brightest waveform
  • A well-defined triangle with a black centre surrounded by red with white in the trailing edge. This indicates an equal distribution of red blood cell velocities at a given point in time and the probe is facing the centre of the aorta. If the waveform has no black centre, this is called spectral dispersion and may indicate that the probe is not facing the centre of the aorta.
  • The incisors or edge of nostrils will be as close to the appropriate depth marker as possible.

Find a signal that meets the above requirements and it may be useful to recheck at different depths once more to ensure the optimal signal has not been missed.

Check the gain manually or use autogain. This will help to adjust the signal quality.

When in run mode, check the cycle time. 5 is the default but can be increased for arrhythmias or decreased if there is noise interference.

Ensure the green follower line is set tightly against the waveform and the white arrows are placed on the triangle.

To refocus:
  • Ensure the probe is at the same depth when the optimal signal was found
  • Turn up the volume
  • Rotate slowly without letting go to find the appropriate signal again before evaluating the parameters.

 

Here are some of the questions we are often asked by practitioners who are new to haemodynamic monitoring using Deltex’s Oesophageal Doppler system.

How easy is it to use the ODM and ODM+ systems?

Most new ODM and ODM+ users find the system easy to use, although operators will derive benefits from familiarity and experience. Evidence suggests it takes no more than 12 cases to become fully competent with probe insertion, placement and manipulation. The manufacturer’s own surveillance reports show that in more than 90% of cases, it takes less than two minutes to get a first good signal. In a typical major operation of 3-4 hours duration, the total time spent interfacing with the monitor and probe is between three and four minutes.

Can ODM really deliver accurate fluid administration guidance?

Yes. The goal is to ensure the patient receives the correct volume of intravascular fluids at the correct time. Individualised Doppler-guided fluid management accurately tailors the amount of fluid to the individual patient in real time under various anaesthetic or sedation strategies.

How safe is ODM?

ODM has been used in over 400,000 patients worldwide. There have been no serious adverse events associated with the system. At the time of writing, eight potential adverse incidents have been reported, none of which were attributed to ODM use after investigation. As with all devices, the manufacturer’s instructions for use lists the contraindications. Note that particular care should be taken in patients known to have existing oesophageal disease or injury or where multiple devices are placed in the oesophagus at the same time.

Can ODM be used in Paediatrics?

Yes. There are dedicated paediatric probes available (KDP), suitable for children of 3kg and above. A paediatric-specific nomogram is integrated into the ODM and ODM+ monitors. The Adult nomogram should not be used for children.

Are the probes reusable?

No. The DPn and I2n range of probes are all Single Patient Use and are labelled accordingly.

Can ODM be used in awake patients?

The I2n range of probes are designed to be placed in unconscious patients (both anaesthetized and sedated) and then left in position after they wake up, providing the option to conduct post-operative fluid optimization. Experienced users also find these probes are well tolerated by fully conscious or lightly sedated patients. However, patients who are likely to attempt to dislodge other invasive devices, may also try to remove the ODM probe.

Can ODM be used at the same time as… ?

  • Insufflation of the abdomen? Yes: ODM is unaffected by insufflation. However, changes in abdominal pressure and consequently venous return cause changes in blood flow in the descending aorta and therefore caution should be taken in interpreting these changes. Similar caution should be applied in the event of major positional change while awaiting the outcome of a fluid challenge (eg Trendelenburg).
  • NG tubes? Yes: Occasionally when using ODM with a nasogastric (NG) tube, you may notice a somewhat diminished intensity of signal. If it is in the path of the Doppler transmission, air in the NG tube can diminish the intensity of the Doppler signal (muted colours on screen). To avoid this, insert the probe before the NG tube, position the probe to the left of the already inserted NG tube, and/or flush the NG tube with saline.
  • Epidurals? Yes: However epidurals and spinal blocks cause different levels of vasodilation around the body and this may cause the derived values of stroke volume and cardiac output to change disproportionately. ODM’s ability to report changes and trends accurately and in the right direction is unaffected. If in doubt, manage the patient’s haemodynamics using Stroke Distance.
  • Diathermy/electro-cautery? Yes, although note that certain models of diathermy equipment emit noise that can intermittently interfere with ODM probe, and may cause loss of signal on the monitor. If the noise is prolonged, then the average cycles-per-calculation can be reduced to maximize the data capture opportunity between the periods of diathermy.
  • Ultrasonic scalpels? Yes: No interference reported to date.
  • Vasopressors or vasodilators? Yes: ODM responds instantly to the effects of vasoactive agents.
  • MRI scanner? No: The probes contain a metal spring.
  • Defibrillators? Yes: ODM is insulated to protect both patient and machine. Best practice is to remove or disconnect the probe during defibrillation.