For years, clinicians have called the Bunnell Hotline to share how they have discovered the advantages of using the LifePulse in tandem with a conventional ventilator. Using a conventional ventilator gives clinicians the ability to strategically deliver Mean Airway Pressure and use recruitment maneuvers to treat atelectasis.
When a patient is experiencing hypoxia or needs a higher FiO2 as a result of atelectasis, a “recruitment rate” may be indicated. Some clinicians call this strategy a sigh rate or sigh breath, backup rate, or conventional rate. Using the term “recruitment rate” can help the medical team remember the objective of these “breaths.”
Clinicians should assess the risks and benefits of providing the recruitment rate and when to apply it. If a patient is hyperinflated, has PIE, or airleaks, the recruitment rate is not indicated. If the patient has asymptomatic atelectasis, the risks may outweigh the benefits. (See Right Upper Lobe Atelectasis).
There are 3 settings to consider on the recruitment rate when the decision is made to implement the strategy.
Rate: A rate of <5 is recommended to reduce the risk of gas trapping as a result of the recruitment rate.
PIP: It is important to be gentle with pressure when implementing a recruitment rate to reduce the risk of volutrauma. Starting at 5-6cm H2O above PEEP and assessing for a gentle chest rise is the best way to find the critical opening pressure of atelectatic alveoli.
I-Time: Inspiratory Time can be your biggest ally when it comes to achieving the objective of a recruitment breath. Starting your patient on a longer I-time can help the gentle PIP reach high resistance areas which need to be recruited. Start at 0.5-0.6 seconds; but remember to be sure you are using lower PIP’s to reduce the risk of volutrauma.
After several hours, FiO2needs should start to improve. It may take some time for v/q matching to catch up with recruited alveoli. If FiO2 needs are not changing, the recruitment rate may need to be adjusted with a longer i-time - incrementally, up to as high as 2-3 seconds. It is important to remember that when using long i-times, you must use smaller delta pressures to avoid volutrauma.
For additional information on long i-time, low delta pressure recruitment maneuvers, call the Bunnell Hotline at 800-800-4358 (HFJV).
Right Upper lobe ATELECTASIS
Right Upper Lobe Atelectasis
Atelectasis is always a concern when treating babies with a mechanical ventilator, and we have learned with the Life Pulse that a few CMV breaths with a PIP sufficient to produce a slight chest rise (temporary recruitment maneuver) along with attention to optimizing PEEP (stabilizing maneuver) can resolve most atelectasis. Still, when we begin to spot a trend in performance, technical issues, or outcomes, we first ask ourselves as many relevant questions as we can in order to understand the perceived issue. In this case, we wondered if RUL is atelectasis a problem specific to the Life Pulse. Is there something we are doing during patient management to promote the problem? Is there something we ARE NOT doing to resolve the problem? Is RUL atelectasis an issue specific to HFJV? Is there something we can do differently to remedy the problem or to avoid it in the first place? We decided to submit these questions to our ad hoc advisory committee, a group of 15 MDs from around North America who have a great deal of experience with HFJV. Their answers were consistent:
RUL atelectasis is the most likely place for collapse to occur, no matter what ventilator is being used on a patient.
The takeoff angle of the RUL bronchus is the steepest and most difficult to ventilate.
RUL atelectasis is fairly common and should only be treated if it is symptomatic.
If the RUL atelectasis IS symptomatic, the advisory physicians recommended the following steps:
Make sure the endotracheal tube position is appropriate.
If the baby is supine, turning his head so that his chin is to the left may help.
Provide 3-5 CMV breaths sufficient to produce a slight chest rise.
Make sure PEEP is high enough to sustain alveolar inflation.
Eliminate the CMV breaths once inflation is stabilized
One of the advisory physicians ended his feedback with a very important cautionary note. He said to be careful about aggressively going after RUL atelectasis if it is asymptomatic. While trying to achieve just a slight improvement in V/Q matching in the RUL, you may jeopardize all of the good V/Q matching you have established in the rest of the lungs.
humidifier temperature settings
Humidifier Temperature Settings
One of our Regional Clinical Specialists visited a NICU recently and observed a great deal of water pooling in the Jet circuit. He pressed the SET button in the humidifier panel and noticed that both the Circuit and Cartridge temperatures were set at 40 degrees °C. He took the opportunity to teach the NICU clinicians about proper Life Pulse humidifier temperature settings.
Humidification on the Life Pulse may need to be adjusted for different environmental conditions.
Where is the patient’s bed relative to air conditioning or heating vents, doorways, traffic patterns?
Is the patient in an open intensive care bed or a closed bed?
The humidifier is programmed so that the Circuit (Gas) temperature is set at 40 degrees °C and the Cartridge (Water) temperature is set at 38 degrees °C. In many situations these setting work fine, but that doesn't mean they are always appropriate.
The Circuit temperature should always remain at 40 degrees because the gas temperature cools as it accelerates through the patient box and the LifePort adapter; we know from our testing that the delivered temperature at the ET tube is 37 degree °C or less.
The Cartridge temperature may need to be adjusted to control humidityand minimize rain-out. If you encounter excessive rainout, the first step is to lower the temperature one degree, clear the excess water from the Life Pulse circuit and wait 20-30 minutes to see if the situation improves. If it does not, drop the cartridge temperature 0.5 degrees and repeat the process.
Your goal is to have the clear portion of the circuit between the humidifier and the patient box dry (small packs of mist or fog are okay, but not droplets) and the green portion between the patient box and the patient covered in mist, so that if you tapped the circuit, droplets would immediately form. We can help you with this process over the hotline, 800-800-4358.
Water droplets that get pushed through the LifePort adapter from the Life Pulse circuit or secretions that come up and out of the patient’s ET tube cause fluctuations in the monitored pressures. The PIP drops and the PEEP rises simultaneously, causing the delta pressure to be very small. Once the moisture moves through the LifePort, the displayed pressures move back--the PIP rises and the PEEP drops. This action is characteristic of moisture interference. If the patient is causing the pressure to fluctuate, it is usually isolated to the PIP dropping with the PEEP staying relatively constant.
If the patient on the Life Pulse is in a closed-style ICU bed (Giraffe style), the easiest way to control over-humidification is to put as much of the Life Pulse circuit inside the closed hood as possible. The shorter the portion of the circuit is outside the bed, the less rainout will occur.
Finally, replace the breathing circuit if one of the following occurs:
- A Circuit Low Temp activates unexpectedly and the low temperature condition is not resolved within 5 minutes after following appropriate troubleshooting
- The measured circuit temperature is noted to be below the set temperature for more than 5 minutes
should i change the circuit?
Should I Change the Circuit?
We received a call on the Hotline from a clinician who was having pressure fluctuations on the Life Pulse. He reported several Loss of PIP alarms and had tried troubleshooting the problem by changing various components. He had changed the LifePort adapter, which is where many pressure problems originate. He had changed the patient box, which contains the pressure transducer and is also a source of pressure monitoring problems. Neither component change remedied the problem.
Then he changed the Life Pulse circuit. Why? For all practical purposes the circuit is a simple tube that directs gas to the patient. The only way the circuit can affect the pressure readings is if it has a hole in it. Otherwise, what goes in one end has to come out the other with no bearing on pressure monitoring.
Frequently when we get calls on the Hotline about pressure problem the clinician has already tried solving the problem by changing the circuit.
Unless there is an obvious hole in the circuit, changing it will not resolve pressure related problems.The only time changing the circuit will solve a problem is when there is a humidifier alarm like Temp High or Circuit Fault. Sometimes, even these alarms are related to humidifier hardware and not the circuit itself.
If you are contemplating changing the Life Pulse circuit for any reason, call the Bunnell Hotline first (800-800-4358) and let us help you troubleshoot the problem. It may turn out that changing the circuit is appropriate, and that’s o.k., but don’t change the circuit unless there is an obvious reason why that’s going to solve your problem, especially if the symptom is pressure related.
troubleshooting: a systematic approach
Troubleshooting: A Systematic Approach
Recently we received a Hotline call regarding fluctuating pressures in the Life Pulse® display. The caller had changed every piece of equipment related to HFJV--except for the LifePort adapter--but the problem persisted.
One simple maneuver solved the problem: repositioning the LifePort™ adapter so that the pressure monitoring line was upward. If it had been done first, a lot of time would have been saved and trouble avoided. In some cases, changing the LifePort™ adapter will solve the problem.
Successful troubleshooting combines a thorough knowledge of the ventilator with a systematic approach to problem solving.
In general, troubleshooting should start with the patient and work back to the ventilator.
Once you have determined that the patient is not contributing to the alarm condition, examine--in order--the LifePort™ adapter, the breathing circuit, the patient box, and the Life Pulse®.
The LifePort™ adapter is the least expensive component of HFJV, and it is the most likely cause of pressure monitoring related issues. Too often, we learn that the Life Pulse®, Patient Box, and a circuit or two have been replaced by the time the Hotline call was made. We instruct the caller to reposition or change the LifePort™ adapter and the problem is solved.
When troubleshooting, it can be a good idea to ask questions:
Is the patient’s interaction with the vent or the patient’s condition causing the alarm?
Is the ET tube in good position and clear of secretions? Is there moisture (over-humidity) interfering with the pressure signal?
Is the LifePort™ adapter properly connected?
Is the pressure monitoring tube positioned upward between 10 and 2 o’clock (advised)?
Did changing the LifePort™ adapter correct the problem?
Is the circuit installed properly?
Are there any kinks or poor connections?
Is the Patient Box running properly? Has the sound or rhythm changed?
Is the Life Pulse® running or has it been affected by electrical fluctuations?
Is it plugged into a UPS?
Is the humidifier running?
Are the contact pins behind the humidifier cartridge okay? Are any of them stuck inward? Do they spring back out when pressed in with a pencil eraser?
Are the temperature controls set properly, 40 degrees C for the Circuit and 38 degrees or less for the Cartridge?
Is there water available for the humidifier?
To be effective at troubleshooting you have to understand how the Life Pulse® works, what the alarms are telling you, and what can be done to correct the situation. Feel free to explore our Advanced Troubleshooting videos to learn more about alarms.
As always, if you can’t resolve the alarm quickly, call the hotline, 800.800.4358, and have one of our clinical specialists help you.
Occasionaly, we receive a Hotline call during which we learn that the Reset or Enter button was pressed inappropriatley. It's essential that you know why and when to press these buttons.
The Ready light in the Alarms section of the Life Pulse is an indicator that tells you when the alarms have been calculated and are “ready” to protect the patient.
Understanding the Ready light is critical to safely operating the Life Pulse. You should never leave the patient’s bedside until the Ready light turns on, indicating the alarms are active. The upper and lower limits for the Servo Pressure and Mean Airway Pressure (MAP) are important indicators that changes have occurred in your patient or ventilator.
The Ready light goes off anytime you press the Enter button or the Reset button. The ventilator waits until the PIP is stable (±1.5 cm H20) for 20 seconds before it recalculates the alarm parameters and turns on the Ready light. The ventilator doesn’t just clear the audible and visual alarms; it also recalculates the alarms around whatever conditions are present at that time.
Therefore, you should rarely press the Enter button or the Reset button during an active alarm condition. Doing so may cause the Servo pressure to reestablish the PIP based on an inaccurate pressure reading. Here is an example to illustrate the importance of the Ready light:
The Life Pulse alarms Loss of PIP due to secretions or moisture interfering with the pressure signal in the LifePort adapter. This problem could be corrected by pressing the Silence button then suctioning the ET tube or changing the LifePort adapter. Instead, the clinician presses the Enter button. Pressing the Enter button does temporarily clear the alarm, but it also causes the all the alarm parameters to be recalculated.
Because the pressure reading is inaccurately low due to the secretions in the LifePort adapter, once the Enter button is pressed the Servo pressure will increase to re-establish the set PIP. The Servo pressure will increase as much as necessary because there are no alarm limits to stop it. The Servo pressure is equivalent to flow. As the flow increases, the delivered tidal volume increases. By the time the set PIP is reached, the patient may be “bouncing off the bed” because the Servo pressure is several psi higher than the previous baseline.
A good rule-of-thumb is if the Servo pressure increases by more than one (1) psi from its previous baseline something has changed dramatically. The Life Pulse should be placed in the Standby mode while the clinician troubleshoots the system to determine the cause. Once the clinician believes they have remedied the cause of the alarm, the Life Pulse can be restarted.
During the restart, the clinician should carefully observe the Servo pressure and PIP to insure that the problem has been corrected and the patient is being ventilated at an appropriate Servo pressure. The clinician should remain with the patient until the Ready light comes on to verify that the alarms are active.
Every effort should be made to keep the Ready light on as much as possible. That means the Enter button and Reset button should only be pressed as necessary to enter new control settings or to intentionally recalculate the alarm parameters, respectively.
If you have questions about the Ready light, alarms, or servo pressure, please give us a call on the Hotline, 800.800.4358.
Troubleshooting Humidifier Alarms is simple and straightforward. The only parts of the humidifier you can evaluate are the contacts between the humidifier and the humidifier cartridge. There are 9 spring loaded contact pins that sit behind the humidifier cartridge and can be accessed when the cartridge door is open.
If these contact pins are stuck or bent, they can cause false alarms. To check these pins, place the humidifier into the WAIT mode. Open the cartridge door and without removing the cartridge let the cartridge door tilt forward. The pins should all be out at about the same level (give or take a millimeter). If any of the pins look more recessed than the others, use the flat end of a pencil eraser to push on the pin or pins. Do not use your finger as electrostatic discharge (static electricity) can damage components in the humidifier.
Push the pins in and out a few times to see if they will return to their normal position. If so, close and latch the cartridge door and take the humidifier out of the WAIT mode. The humidifier should return to normal functioning without any alarms. If the pin(s) do not return to their normal level, the ventilator will need to be replaced to solve the problem.
Even if the pins return to their normal position, this fix is temporary. The pins will need to be replaced sooner rather than later.
If the pin(s) are fine, close and latch the cartridge door and take the humidifier out of the Wait mode. If the alarm returns, the circuit itself is faulty and will need to be replaced. If the circuit is less than 8 days old, hold on to it so you can return it to Bunnell for an evaluation and possible credit.
To return a circuit to Bunnell call Customer Service at 800.800.4358 ext. 6 for a Return Authorization number (RA#). To generate an RA# we will need the Lot# from the front of the cartridge and what alarm was generated when the circuit failed. Attach the RA# to your paperwork and/or the package that the circuit is returned in, so our receiving department can log it in when it arrives.
Once the Failure Investigation is completed you will receive a Resolve Letter telling you the results of the evaluation and whether a credit will be issued.
Frequently, we get hotline calls requesting information on the best way to deliver bronchodilators or other inhaled medications during HFJV. We asked the following questions to a group of Physicians and Respiratory Therapists from around the world who have a great deal of experience with HFJV or expertise in mechanical ventilation of babies. Their answers were consistent and insightful.
When would you consider an aerosolized medication for a patient on HFJV?
Generally, the answers to this question were… “Never." Possibly for Chronic Lung Disease (BPD), but mostly, aerosol treatments are not indicated nor likely effective during HFJV. Even with BPD babies, aerosols are iffy, as one responder indicated: "While babies with BPD typically have increased airway resistance, it is NOT bronchospasm, so bronchodilators don’t have any effect."
The answers suggested that it is possible for bronchodilators to be effective, but more likely not, primarily due to two issues: the double-helical, bidirectional flow that occurs during HFJV, and the fact that babies on HFJV likely have diseases or disorders that won’t respond to bronchodilators.
One responder said that during HFJV, they may try to stimulate beta-2 adrenergic receptors with albuterol to drive potassium back into cells in cases of extreme hyperkalemia.
Is it wise to place the Jet in Standby for the duration of the aerosol treatment?
Responders thought this was a bad idea. Losing HFJV for the duration of the aerosol treatment would be more detrimental than the medication would be beneficial. The patient likely will not tolerate well the loss of HFJV, and support from the CMV would have to be added while giving the aerosol treatment, which could aggravate the patient’s injury or create new injury.
Are Meter Dose Inhalers a better option? Probably not. Some responders thought they might be a better option, but we don’t know. Another issue is that some of the medications you might consider may not come in MDI form.