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Invasively Ventilated Patient Care

Building on our previous foundation areas regarding oxygenation, concepts and non- invasive ventilation let’s look at caring for a patient having invasive mechanical ventilation.  Hopefully, when you start in your NU2ICU environment opportunity will allow you time to learn, observe and practice.  However, if it’s busy, there is no one else and management believe it’s safe, you might be thrown in the “deep end” straight on to a lightly sedated, very dependent, intubated patient.

Lets focus on the practical care of an Invasive Positive Pressure Ventilated  (IPPV) patient

So let’s prepare!

To quickly overview what we have learnt on NU2ICU …

  • we breath by the mechanism of negative pressure
  • the intercostal muscles and diaphragm contract, the thorax & lungs expand & intrapulmonary pressure falls below that of the atmosphere
  • air enters the lungs to equalise pressure

Image – https://www.britannica.com  accessed 19th April 2018

Positive pressure ventilation uses a mechanical drive to deliver increased air mix into patient’s lungs either invasively or non-invasively,  for this discussion its invasively.

“Ventilation is not a simulation of breathing, rather a substitute with unavoidable side effects”

and we will discuss those side-effects later on!

To invasively ventilate we need to “invade” with a secure airtight airway (cuffed).  The cuff:

  • prevents air escaping into the upper airway / atmosphere
  • helps prevent secretions entering lungs

Two ways to achieve this (other than laryngeal mask):

  • EndoTracheal Tube (ETT) usually via the mouth, infrequently via the nose
  • tracheostomy tube

PLEASE NOTE: the cuff on either type of tube DOES NOT hold it in place

Image – https://www.slideshare.net/HaseebManzoor/endotracheal-tube  accessed 20th April 2018

An EndoTracheal Tube / airway (ETT)

 

Some types of Tracheostomy Tube / airway (many more are available)

 

Indications  for intubation and invasive mechanical ventilation are those “who can’t breathe and those who wont breathe”

Respiratory failure

  • Type I:    PaO2    < 60mmHg on room air (pneumonia etc)
  • Type II:  PaCO2 > 60mmHg on room air (exacerbation COAD, severe asthma etc)

Airway protection due to

  • obstruction / inability to maintain airway
  • ↓GCS
  • CNS impairment 2° to intracranial pathology
  • oedema

Vital capacity <15ml/kg

  • NM disorders (e.g. GBS, MD etc) or restrictive acute burns

Removal of secretions

Haemodynamic instability

Trauma requiring immobilisation

General anaesthesia

Reducing intracranial pressure

 

Goals  of invasive mechanical ventilation

  • ↓ respiratory distress
  • ↓ Work Of Breathing
  • optimise gas exchange
  • facilitate lung healing
  • maintain haemodynamic stability
  • protect airway
  • operative / investigative procedures

 

Risks  of invasive mechanical ventilation (include but are not limited to)

  • Ventilator Associated Pneumonia (VAP) see below
  • airway / lung trauma (suctioning, barotrauma, Ventilator-associated lung injury (VALI), etc)
  • diaphramatic atrophy

 

VAP

Pneumonia commonly acquired by patients who had mechanical ventilation within 48 hours of the onset of infection (doesn’t include NIPPV)

Gram-negative organisms colonise the oropharynx in critically ill patients and this can translocate from lower part of the GIT by dysfunctional oesophageal and intestinal motion (micro-aspiration)

Clinical markers

  • elevated temperature
  • increased volume / thickness of tracheal secretions
  • ↑WBC count

 

Helping prevent VAP includes:

 

Intervention Rationale
Mouth care according to oral assessment decolonisation of oral flora
Head of Bed elevated at least 30 degrees prevents passive regurgitation of gastric contents into lungs
Regular suctioning to encourage coughing (3/24 assessment for need to suction and min 6/24 suction) facilitate clearance of secretions
Early enteral feeding sufficient caloric intake to facilitate healing
Continuous subglottic secretion management decrease microaspiration
6/24 measurement of gastric residual volume decreases likelihood of aspiration pneumonia from feed intolerance
Pressure area care (turning patient side, back,
side 3/24)
movement of lung secretions which facilitates drainage
Lighter sedation (see below) encourages inherent coughing
Meticulous hand hygiene decrease added infection risk
Routine ventilator circuit / HMEF changes per your unit guidelines
Invasive cuff pressure checks per your unit guidelines
Anything safely minimising length of ventilation maximise patient for extubation

Sedation

ICUs generally now have:

  • moved to opioid-based (fentanyl) / hypnotic (propofol) / selective alpha 2 agonist (dexmedetomidine) sedation and avoiding any benzodiazepine usage as able
  • introduced ‘sedation holds’ (often combined with spontaneous breathing trials); i.e. turning off all sedatives and analgesics in appropriate patients, and allowing them to ‘wake up’
    • if rapid and complete, the infusion may be restarted at the same rate
    • if slow, then the infusion can be restarted at a lower rate when the patient is awake enough

Sedation depth is more closely monitored at targeted levels (RASS or similar) hopefully enabling earliest possible safe extubation

 

Question – when looking after invasively ventilated patients do we need to re-establish our ICU Safety Net?

Question answer HINT…  Patient checks at start of shift for a ventilated patient include.. (on top of our usual ICU Safety Net!)

  • is the airway secure?  Look at condition of tapes / holder
  • check mode of ventilation and ventilator alarms with T/L
  • oxygen concentration / percentage as ordered / expected SaO2 and/or PaO2
  • size of device and length in cm at teeth/gums for ETT as documented
  • etCO2 monitoring in place and working
  • method of humidification / presence of water supply
  • assess availability of emergency equipment
  • check alarm limits on patient monitoring for expected HR / BP and/or MAP
  • expected level of RASS or similar
  • cuff check / cuff pressure and document
  • auscultate chest, respiratory assessment
  • secondary survey / mouth, eye, nasal care / suctioning / refastening if required

IF UNSURE ALWAYS ASK!

Airway Safety

ETT security

  • always have a senior nurse in-charge of the airway device during positioning of device or patient (IE someone who knows what to do if it falls out / moves considerably / blocks)

Routine fastening care is performed (for whichever system of invasive airway fastening / security your ICU uses)

  • minimum performed once a shift
  • tapes or fastener should be firmly attached and never too tight
  • ETT should be moved to opposite side of mouth once a day ensuring it is moved over the tongue with associated full oral assessment
  • one member of ETT security team should ALWAYS be a trained or CCRN
  • may require to be moved more than once a shift
  • recheck cuff pressure post fastening procedure
  • NEVER  secure an Orogastric drainage / feeding tube to the ETT

Image – www.anchorfast1.com  accessed 19th April 2018

ETT length checking

  • performed minimum once a shift usually
  • measured only at immovable landmarks – teeth, gums etc NEVER the lips

ETT / Tracheostomy cuff pressure management

  • performed minimum once a shift
  • aim pressure in GREEN zone (22–32cmH2O – in the middle is best!)
  • if a cuff leak is noted post check please recheck once more and if required alert your T/L should it be outside that target pressure or not forming a proper seal

Image –  http://www.yms.co.za/product/et-tube-cuff-manometer “edited” accessed 19th April 2018

Tracheostomy security

  • fixation with soft velcro neck bands or cloth tape and trache sponge / bib to decrease pooling of insertion site exudate / maceration
  • tighten to allow 2 fingers underneath only (snug but not overly tight)
  • check tightness 3/24 and with suctioning

 Suctioning

  • facilitates removal of endobronchial secretions / encourages coughing
  • maintain patent airway
  • promote gas exchange
  • helps prevent effects of retained secretion / infection
  • obtain tracheal aspirate specimen

Assess need for suction 3/24, to be performed at a min 6/24 hrly

  • look at previous suction documentation to assess frequency and amount yielded
  • may need “stress reliever” change if copious amounts

Your ICU may use open or closed suctioning techniques although most use closed for reasons of decreasing ventilator disconnections and the risks associated with that disconnection

Our selected catheter for suctioning must be as indicated for the size ETT / Trache

Formula  for suction catheter size (Fr)  =  [ETT/Trache size (mm) minus 1]  X  2

Examples

  • size 8 ETT/Trache:  {8 minus 1} then multiply by 2  = 14Fr
  • size 7 ETT/Trache:  {7 minus 1} then multiply by 2  = 12Fr

REMEMBER – better TOO small than TOO large  when suctioning

 

Image – https://www.vitalitymedical.com/suction-catheter.html  accessed 20th April 2018

The closed suctioning process includes;

  • hand hygiene with soap or alcohol based gel
  • prepare Water For Injection (WFI) fluid as flush in 10ml syringe (WFI kills bacteria and saline doesn’t)
  • PPE including face shield (disconnections may spray in your face)
  • ensure suction working and waste reservoir not full
  • inform patient of impending procedure (always tell them whats going on even if heavily sedated)
  • pre-oxygenation @ 100% O2 via ventilator for minimum 6 breaths (wait for saturation to start to increase above patients known “normal” on monitoring)
  • if above cuff access port is available aspirate now prior to suction of the lower airway
  • perform first pass  – unlock suction system and feed catheter until resistance (carina) / patient coughs, withdraw catheter 1-2cm and then apply suction, slowly (maximum 10 seconds total) draw catheter back until black mark on catheter tip is level with marker on suction system.  Observe for amount and colour of secretions, reassure patient as required (if difficulty seek help!)
  • if patient overly distressed by process give (as ordered) a low dose bolus of sedation, trying not to suppress the cough reflex if able
  • repeat as indicated, waiting for patient comfort and stable O2 saturations between suctioning, continue until secretions adequately removed
  • if patient saturation has recovered post suctioning manually disable 100% O2 and return back to pre-suction FiO2 to avoid excess oxygenation
  • flush suction system with WFI as indicated (minimum at end of procedure)
  • lock suctioning access system, disconnect suction hose, reassure patient as required
  • clear patient oral secretions with yankeur device or similar
  • ensure patient comfortable and safe and observe for ETT / tracheostomy security
  • remove PPE, hand hygiene, document process including observed outcomes

IMPORTANT:   find out if invasive suctioning is a 1 or 2 staff member process in your unit to comply with your units minimum standards

Open suction techniques are similar but require a greater observance of sterile / clean gloved hand process during introduction and catheter flushing – see your local procedures and guidelines

 

Document  your process

By assessing and recording

  • colour
  • consistency (although not specifically thick sputum can be an indicator of infection or insufficient humidification)
  • volume
  • strength of cough

Inform TL / MO if concerned about anything during suction process or new blood present in sputum

 

Risks  of suctioning

  • hypoxia
  • atelectasis (lung collapse) by loss of PEEP
  • loss of artificial airway (dislodged or pulled out)
  • trauma to carina (can result in blood stained tracheal aspirate from mucosal injury)
  • suctioning is very uncomfortable for the patent.  They may become agitated / distressed
  • ineffective – modify sedation as indicated to ordered level to facilitate

Mouth Care

Perform, with suctioning to cluster our care to decrease patient distress,  3/24 or as per your unit minimum standards

Assess

  • oral hygiene – general condition
  • state of tongue – coating, dryness, asymmetry

Tooth Brushing – is encouraged 2 times daily BUT does pose substantial risk to the airway from dislodgement of ETT, vomiting, aspiration and other issues

It is not just “a simple thing to do” and ensuring patient safety while poking about in the mouth lowers the risk of trauma, inducing vomiting etc.  Seek assistance from your T/L until you are both satisfied the process is well practiced and understood

The use of dilute chlorhexidine mouthwash 12/24 to assist in decontaminating oral secretions and therefore lowering risk of infection from micro-aspiration is also beneficial for the ICU patient but high frequency application / high fluid concentrations may stain teeth and lead to oral mucosal lesions in some patients, also always check patients allergy records prior to use

Dry mouths may be treated with frequent water soaked mouth probes or artificial saliva if available, treat dry lips with a paraffin based coating to seal the integument against further dehydration

Inform TL / MO if concerned or blood present in mouth / loose teeth etc


Eye care

While sedated although the eyes may appear closed small gaps in the eyelid closure may allow areas of the sclera and / or cornea to become dry and if this occurs untreated may cause permanent scarring and visual difficulties later on.   Routine care of the IPPV patient includes cleaning of the external eye lids with a careful wiping with soft gauze or a cotton ball soaked in saline, this should be followed with a single squeeze application of your hospitals preferred eye lubricant to both eyes ensuring the corneas have a film coating post application and both eyes should be observed to be closed after this procedure.

Please note that vision is very blurred for the patient with lubricant instilled so patients being extubated, or sedation lightened to assess ability for extubation, should have only the wiping process done during that time

This should be performed 3/24 or according to your local ICU policy


Nasal Care

At the same time as performing suctioning, mouth and eye care (3/24 or to your units policy) please also inspect inside the nares as the usually moist inner lining of the nasal passages may dry with lack of humidified air flow (as upper airway bypassed) if it’s looking very dry then gently apply a very thin layer of paraffin based coating to external and visible internal areas – do not “shove” anything too far inside due to risk of trauma / discomfort.  Dry nasal passages can be very painful for patients

Cluster your care in IPPV patients to help you ensure great time management, the best possible outcomes and decrease their complications of invasive mechanical ventilation


Other things  to consider during IPPV (the list goes on)

Sedation

  • invasive lines for drugs and monitoring
  • line bacteraemia/sepsis
  • increases length of stay = ↑ morbidity

Reduced mobility = venous stasis

  • ↑ risk of DVT
  • heparin sub/cut 5000u 12/24hrly or Enoxaparin or similar (if not contraindicated) and/or Sequential Compression Devices (SCD’s)

Nutrition

  • naso /oro gastric tube placement
  • feed intolerance = ↑ risk of aspiration and insufficient caloric intake
  • immune compromise = ↑risk of infection
  • “refeeding syndrome” in very nutritionally deprived

Elimination

  • diarrhoea / constipation from feeds / opioids / lack of valsalva (can’t bear down)

Integument

  • pressure areas including from ETT / N/OG tube and / or their mounts

Communication

Pain / discomfort / delerium

After ICU Post Traumatic Stress Disorder (PTSD) / disability


Terminology of IPPV

Mean Inspiratory Pressure: the average pressure required to force gas flow through the resistance of the airways

Positive End Expiratory Pressure (PEEP / Continuous Positive Airway Pressure – CPAP / End Positive Expiratory Pressure – EPAP  *ALL are same thing): PEEP is the application of a constant airway pressure so that at end-expiration the pressure in the airways does not return to atmospheric pressure

Pressure Support: augmentation of the patient’s spontaneous inspiration effort to a pre-set pressure

PSV: Pressure Support Ventilation

  • spontaneous mode which acts to support the patient’s breathing  throughout the respiratory cycle.
  • used to facilitate weaning from the ventilator

SIMV: Synchronised Intermittent Mandatory Ventilation

  • incorporates mandatory delivery of a pre-set rate and volume
  • the patient can also take spontaneous breaths

Tidal Volume:  volume of gas moved into or out of the lungs in a single breath (about 5 – 8ml/kg)

Respiratory Rate:  number of breaths delivered each minute

I:E ratio:  time allowed per breath divided into inspiration / expiration phase (default 1:2)

Minute Volume:  tidal volume x respiratory rate over 1 minute

FiO2fraction of inspired oxygen concentration (21%  =  0.21)

Intubation:  the process of inserting an artificial airway to facilitate mechanical ventilation

Extubation:  the removal of that airway when deemed unnecessary for the patient

 

 

So there it is, your foundation in the care of a invasively ventilated patient … again if only it was that easy!

NU2ICU

 

REFERENCES

AACN essentials of critical care 1st Edition 2007  by Marianne Chulay, Suzanne Burns

ACCCN’s critical care nursing 2nd Edition 2012 by Doug Elliott, Leanne Aitken and Wendy Chaboyer

Essentials of Critical  Care Nursing: a holistic approach 1st Edition 2013 by Patricia Gonce Morton, Dorrie K. Fontaine

lifeinthefastlane.com/ccc/ventilator-associated-pneumonia-vap/  accessed 18th april 2018

Oh’s Intensive Care Manual 7th Edition 2014 by Andrew Bersten, Neil Soni

www.cdc.gov/hai/vap/vap.html  accessed 13th April 2018

 

More reading

ARTERIAL BLOOD GASES

PULSE OXIMETRY & HUMIDIFICATION

VENTILATION ASSISTS

VENTILATION SEDATION & POSITIONING