A 35 year old male African American Relevant to mortality rates patient Name omitted for anonymity as required by the Nursing and Midwifery Council Nursing And Midwifery Council, 2008 was admitted to the Surgical High Dependency Unit (HDU) following a traumatic fracture of his right femur and right wrist after an un-witnessed assault in the early hours of the morning. Preoperatively the patient presented as being haemodynamically stable with all observations being within normal limits. Induction, intubation and surgery all progressed without any concerns until the patient was recovering within the post-anaesthetic care unit and suffered from a dramatic episode of desaturation to an SpO2 of â‰ˆ60% (Â±3%). During this emergent crisis the patient required 15l of oxygen via a non-rebreathe mask to maintain an SpO2 â‰¥ 90%. After a review by the anaesthetic staff he was transferred to the HDU and placed on high flow nasal cannula (FiO2 0.7 @ 60 Litres). He maintained his saturations and intact neurological observations for a further four days on this intervention, but worsened on the fifth day with a dramatic increase in Fi02 requirements (1.0 @ 80 Litres) and a decrease in his neurological assessment; Glasgow Coma Scale (GCS): Eyes 3, Voice 3, Movement 4 and a referral was made to the Intensive Care Unit (ICU). Following review the patient further deteriorated and his combined GCS fell to 5 with aspiration of stomach contents and he required rapid intubation and transfer to the ICU for further treatment, ventilation and investigation. He arrived in the ICU in the early afternoon and a chest x-ray (CXR) showed diffuse air-space disease and following the Acute Respiratory Disease Syndrome (ARDS) equation (PaO2[mmHg]/FiO2 = < 200) (Britos et al., 2011) the diagnosis of ARDS was made.
The following will discuss the pathophysiological process of ARDS and will highlight the role nursing staff can play in helping to treat this condition through evidence based care and will highlight areas of good clinical practice and areas further development can be made as per relevant research.
ARDS can be caused by a many different causative factors (This list is not exhaustive):
Massive Blood Transfusion
Pneumonia (Griffiths, 2007)
It can be caused by direct or in-direct lung injury and further falls into two categories; a local inflammatory syndrome in the lungs (Primary ARDS) or as a wider systemic inflammatory response (Secondary ARDS). The patient in question suffered from a direct lung injury through aspiration of gastric contents and fell into the category of primary ARDS as the inflammation was localised to his lungs.
ARDS has 3 main recognised phases:
(Bench and Brown, 2011)
ARDS develops, in this case, when cytokines and exogenous agents injure the epithelium and endothelium of the lung in response to an insult to the lung tissue. This affects the lungs in a non-homogenous style, leading to a non-uniform involvement of the lungs which is one of the main factors leading to difficulty in ventilation.
Due to this release of cytokines via macrophages and the inflammatory response that these precursor the alveoli fill with a high protein oedema (Ferguson et al., 2012). This leads to arterial hypoxemia, decreased lung compliance and surfactant dysfunction. This could be seen in the patient who, whilst on pressure assisted ventilation, could only get tidal volumes of ~300mls with a peak airway pressure of 32 cmHÂ²O. This is proven in research by lung biopsies taken during the acute phase of ARDS; these show the diffuse alveoli damage with protein positive oedema, neutrophils, macrophages and erythrocytes present (Ware, 2006).
This oedema is caused by increased permeability within the pulmonary capillary beds which leads to an increase in transvascular fluid transfer into the alveoli due to them being a point of low concentration for fluid to cross into (Diffusion) (Johnson and Matthay, 2010).
The level of "flooding" within the alveoli is dependent on several factors; interstitial oedema levels, the efficiency of the alveolar epithelium to remove fluids and the presence of other injury to the alveoli.
With this presence of oedema within the alveoli epithelial injury takes place due to the on-going inflammatory response of the bodies own immune system. This leads to flat type I cells (90% of alveoli surface) being damaged and adding to the barriers for efficient gas exchange and type II cells, responsible for surfactant production, being either retarded in effectiveness or destroyed.
This damage was evidenced by the fact that the patient required an FIO2 of 1.0 with a positive end expiratory pressure (PEEP) of 20 to maintain an SpO2 < 90% and on closed suctioning diffuse secretions presenting the same as pulmonary oedema were present.
Ventilation, whilst medically led, is adjusted by the bed side nurse based on arterial blood gas results, tidal volumes, SpO2, work of breathing and spontaneous effort. It is incredibly beneficial to the patient to allow them to make respiratory effort as this allows the diaphragmatic muscles to maintain strength and to enable a certain amount of negative pressure ventilation to occur.
In relation to the patient he initially was placed onto Biphasic Positive Airway Pressure ventilation; this is a fully mechanical mode of ventilation which relies purely on positive ventilation to drive respirations. This means that the patient did not make any respiratory effort himself, leading to the added risks of barotrauma and volutrauma. It is well identified that positive mode ventilation must be used for the most minimally available length of time as the risks in the long term far outweigh the benefits of controlled ventilation.
Once the patients' sedation was reduced enough to allow him to make respiratory effort he was placed onto pressure assisted spontaneous breathing. This allows the patient to make respiratory effort and the ventilator supports this negative pressure by adding a set amount of positive pressure to increase tidal volumes. Whilst the majority of evidence points out that this is highly beneficial to the patient it also has some intrinsic risks; if the patient suddenly becomes more compliant then there is a further risk of volutrauma, anxiety and pain can increase the respiratory rate to the point that the patient is blowing off too much CO2 which can lead to worsening blood gases due to an increase in pH (Although in this case the patient was already acidotic so this could have a beneficial ramification on blood results).
It is also important to point out that the patient was receiving low tidal volumes on ventilation as this is seen as being beneficial to survival (Wang et al., 2011) through the lack of risk of volutrauma and barotrauma. Critically this can also be argued against as it can impair gas exchange due to dead space ventilation and decreased CO2 clearance (Johnson and Matthay, 2010).
By allowing the patient to make spontaneous effort with added PEEP and pressure assist the aim is to maintain recruitment of the alveoli. Unfortunately the patients' condition worsened and at day nine the clinical decision was made to change his mode of ventilation Airway Positive Release Ventilation (APRV).
APRV is now recognised as a key tool in the treatment of ARDS (Checkley et al., 2008) as it maintains recruitment and keeps the alveoli open much more effectively. Critically though APRV can be highly uncomfortable for patients (Lucangelo et al., 2007); research does show that APRV is more effective if the patient makes some spontaneous effort (Checkley et al., 2008), but this must be balanced against the patients' tolerance of it. With this patient APRV was not tolerated at all at levels of sedation which supported spontaneous effort. Therefore the patient required muscle relaxant to enable the ventilation to work as efficiently as possible. This again leads to the risk of respiratory muscle wastage and the complications that come from positive pressure ventilation.
On top of this it may have been of benefit to start the patient on APRV within the first few days of his arrival to the unit; evidence from Checkley et Al (2008) shows that APRV could improve outcomes if used from day one of mechanical ventilation in ARDS. It is recognised though that the clinical decision to go to APRV lies with the medical staff and not the nursing staff (Kaplow and Hardin, 2007).
Sedation and Analgesia
The majority of ARDS patients require some form of sedation whether that be in the form of a true anaesthetic (Propofol) or a barbiturate/opioid mixture (Russell and Walley, 1999).
By using sedation, especially an opioid, the patients respiratory can be decreased, but not fully stopped, aiding in mechanical ventilation to support their own efforts whilst preventing the patient from "fighting" the ventilator (Arroliga et al., 2008).
The use of sedation though must be titrated to the patients required level. There is no perfect formulation for patients' requirements and as such the nurse must be continually assessing the patients' sedation levels (Calfee and Matthay, 2007).
Our patient was given intravenous propofol and alfentanil at levels that kept score as a -4 (Elliott, Aitken and Chaboyer, 2011) on the Richmond Agitation And Sedation Scale (See figure 1.1). This enabled us to ensure the patient was still neurologically intact to the extent of waking and to maintain the patients comfort.
Great thought must be given though to the use of strong opioids due to the other effects they have on the body; constipation, itching and altered neurological status, but comfort MUST be maintained at all times in the ITU (Arroliga et al., 2008).
Positioning of patients is paramount to maintaining lung efficiency and to enable areas of healthy lung to work at peak efficiency. This also aids to minimise the amount of dead space being ventilated within the lungs and allows for proper circulation of gases within.
With the oedema for ARDS it is important for us to aid the patients' own body in the removal and clearance of this and any other secretions that may occur following aspiration (Matthay, 2003).
Changing a patients position regularly can aid in improved gas exchange, decrease the incidence of ventilator acquired pneumonia and help to prevent atelectasis (Deutschman and Neligan, 2010).
Our units' policy is to turn patients every 2-3 hours utilising a tilt to the left and right and on their back. Proning of patients is quite rare, but was used with this patient, at day 14, as evidence suggests that this is highly beneficial in ARDS (Ware, 2006), but we should probably considered it far earlier as research suggests early proning can lead to a decrease in ITU days (Erickson, Martin and David, 2009), but not in mortality (Russell and Walley, 1999). Critically the justification for proning a patient must also take into account the risks inherent in such a manoeuvre; dislodging of invasive devices, including the airway, and difficulties in maintaining oral hygiene and pressure area care (Scanlan, Heuer and Sinopoli, 2010).
Whilst the patient was proned during the daytime hours, at night he was repositioned into the left, right, back routine. This enabled him to be upright tilted at a 40 degree angle which, as evidence suggests can be beneficial again in lowering the pressure on the diaphragm (Bull, Clark and McFann, 2010). This also aids in pressure area care as any critically ill patient will have a level of retardation to their healing capabilities and even more so in ARDS (Arroliga et al., 2008) and therefore be at higher risk of developing skin breakdown.
Tracheal Suctioning and Oral Care
Within our unit it is normal for closed circuit suctioning to be placed on any ventilated patient, whether it be for a couple of hours or for weeks and our patient was no different.
This enables us to continue to suction the patient without breaking the ventilation circuit and maintains patients' oxygenation when they require a high FiO2 (McLuckie, 2009). Critically though closed suction means the same catheter is used for up to 3 days which can lead to, through misuse of the nurses not cleaning the catheter properly with NaCl 0.9%, further risk of infection from the catheter harbouring any bacteria from the patients' chest (Esteban, Anzueto and Cook, 2004). Therefore proper use must be enforced.
Oral hygiene and the use of subglottic aspiration ports are also very important in the prevention of ventilator acquired pneumonia (VAP) and further increase in already present infection. On our unit we do not routinely use continuous suction of subglottic ports and perhaps this patient could have benefited from it as he had diffuse secretions and research suggest that this can lower the incidence of VAP and be highly cost effective (Gujadhur et al., 2004).
Communication and Family
One of the key roles a nurse can play is that of communicating openly and honestly with family members (Adam and Osborne, 2009). Sadly the patients' next of kin (Wife) lived over 100 miles away and due to financial and social situations was unable to attend the hospital for any length of time and so the majority of communication had to be made over the telephone. This led to major issues in terms of confidentiality and care decision formulation.
The units policy is to ensure that the person phoning is the identified next of kin (Or authorised third-party) to be able to pass on any information. This is enforced by making sure the caller knows certain personal facts about the patient. This allows us to maintain a high level of confidentiality, but is still open to abuse through other parties' false identification.
It is well identified that critical care nurses are in one of the most rewarding positions to be helping families with the situation at hand (Kaldem and Daqian, 2011), but are also in a position where care must be taken to ensure information is passed on in a manner that the families can understand and to facilitate informed decisions based upon this information (Adam and Osborne, 2005).
Due to the constraints of the next of kin being so far away, whenever she did visit there was a risk of "overloading" her with information as they had a very rudimentary understanding of medicine.
To counter this, and at their request, the chaplaincy was involved to help her emotionally and spiritually in this situation.
Visiting hours were also not enforced for the relatives for the few times they managed to attend the hospital as this meant we could allow them to spend time with their relative in the hopes that this would both reassure the patient and the relatives. In the ITU though this can have the reverse effect, and did in this case, of scaring the relatives due to the complexity of the care and devices we were using (Kaldem and Daqian, 2011). To try and lessen this fear education was undertaken into what each item at the bedside was and this did seem to reassure the relatives somewhat, but further time had to be dedicated to the family to ensure their emotional status remained ok.
In conclusion it is clear to see that improvements can be made within our unit to maximise the care we give patients with ARDS in the regions of positioning and ventilation.
Our unit appears to match much of what the research suggests about ARDS; Titration of sedation, pain relief, VAP bundles and good hand hygiene rules to name a few.
Positioning can be nurse led in terms of head tilt and supine/lateral positing, but perhaps if the nurses suggested proning earlier, and showed comfort in making this change in position, the medical staff would consider it earlier as an option as well. While this may not have an effect on mortality, days spent in ITU is reduced and therefore it is an economic saving as well as an earlier discharge from the ITU for the patient if they survive.
Sadly, as with any condition seen within the ITU, even following these principles of best practice can still have a poor outcome for the patient and, in the case of the patient referred to in this essay the worst possible outcome occurred; death.
Death is not the end of the nurses' role though; after care for the family, including support and information via verbal and leaflets must be given to maintain the standards that the NMC demands.
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