Is plastic in the trachea during cardiac arrest harmful?

I have being reflecting lately on intubation of critically ill patients.  There are few other topics in prehospital care which raise strong opinions, often from polar perspectives.  There are numerous papers on the safety and effectiveness of advanced airway management in multiple populations (http://wp.me/P2N7pf-2K) often with conflicting results.

Unfortunately, training in airway skills is very heterogeneous – with the majority of paramedics learning all airway skills in simulated settings and utilising these skills infrequently on real patients.  All paramedics are expected to be proficient at bag mask ventilation, insertion of oropharyngeal airways (OPA), nasopharyngeal airways and supraglottic airways (SGA) however most have learnt these skills on manikins; will have infrequently used these skills in practice and typically use/attempt these skills without a more senior mentor being present.  It is therefore difficult for paramedics to acquire / maintain “basic” airway skills of which the use of an OPA and ability to mask ventilate are the most important.  Additionally, there is evidence that paramedics success rates for insertions of laryngeal mask airways is well below what is expected (i.e. > 90%).  The majority of intensive care paramedics (ICPs) in Australia have undertaken some perioperative airway training however this is of variable duration (typically between 1-4 weeks) with some jurisdictions requiring a minimum of 20 intubations.  ICPs are aware after this period of training that the perioperative area is very different to the prehospital environment when it comes to endotracheal intubation.  Furthermore, the opportunity for the majority of paramedics to perform endotrachael intubation are infrequent.

I want to take the opportunity to explore why placing a plastic tube in the trachea during cardiac arrest might adversely affect outcomes and propose ways that these factors might be overcome

Possible mechanism Solution
Intubation can impair the delivery of effective and minimally interrupted chest compressions
  • Attempts at intubation must not interfere with chest compressions (the person doing compressions should not stop)
  • Attempt all intubations with a bougie – it is easier to intubate the glottis with a bougie than an ETT especially during CPR
  • Skill train paramedics to intubate with a bougie without interrupting chest compressions
  • Only attempt intubation if glottis view is IIb or better – chances of first pass success with grade III and IV views without interrupting chest compressions are unlikely
  • Monitor CPR performance
  • Attempts at intubation might be delayed until ROSC or gasping respiration ceases – great article by Gordon Ewy –http://www.sjtrem.com/content/pdf/1757-7241-20-65.pdf
Intubation can lead to hyperventilation of patients
  • Have paramedics train and practice delivering one breath every 6 seconds
  • Use a portable ventilator
  • Use objective measures of ventilation rate (i.e. waveform capnography)
  • Monitor CPR performance
Paramedics only intubate infrequently
  • It is true that the majority of paramedics intubate infrequently reflecting the incidence of cardiac arrest
  • Paramedics (and their employers) should ensure regular refresher training and ongoing opportunities to maintain airway skills (also important for ED and ICU docs)
  • Use an airway registry to document prehospital intubation attempts prospectively
Oesophageal intubation will not be recognised
Paramedics will become fixated on needing to definitively secure the airway
  • Change the culture that being able to ventilate the patient is the only absolute requirement in cardiac arrest
  • Change the culture that being able to intubate is the most important measure of a paramedics greatness
  • Ensure that an “unsuccessful” intubation drill is in place, practiced and is utilised
  • Introduce intubating LMAs and/or second generation LMAs

 

All “intubators” (whether medical or paramedical) have a responsibility to not harm their patients.  Whilst proceduralists like performing procedures, there is a patient at the end of every procedure.  It is highly unlikely that the endotracheal tube reacts with the mucosa of the trachea in such a way that outcomes are worse – there must be other reasons.  In my mind, all of which readily come to mind can be overcome quite readily.

Bottom line

  • Intubation must not impair effective and continuous (or minimally interrupted) chest compressions
  • Attempts at intubation must be brief, consider delaying until after ROSC
  • Do not hyperventilate – use a ventilator if available (if unavailable lobby the bureaucracy)
  • Optimise first pass success – optimise positioning, use external laryngeal manipulation, use suction and use a bougie
  • Waveform capnography should be used routinely (if unavailable lobby the bureaucracy)
  • If any difficulty – move on (don’t let your ego get the better of you – display clinical leadership by implementing plan B which facilitates oxygenation / ventilation

Paramedic controlled analgesia – does this meet the needs of patients?

Over the past several years many papers have been published about various aspects of prehospital analgesia (http://wp.me/P2N7pf-k) and of inadequate analgesia for acute pain (oligoanalgesia). A recent study by Walsh et al. (Prehosp Emerg Care. 2013 Jan;17(1):78-87) again addresses paramedic attitudes regarding prehospital analgesia in a qualitative study using a grounded theory methodology.  The identified the following major themes in their study: 1) a reluctance to administer opioids to patients without significant objective signs (e.g., deformity, hypertension); 2) a preoccupation with potential malingering; 3) ambivalence about the degree of pain control to target or to expect (e.g., aiming to “take the edge off”); 4) a fear of masking diagnostic symptoms; and 5) an aversion to aggressive dosing of opioids (e.g., initial doses of morphine did not exceed 5 mg).  The study authors conclude “A number of potentially modifiable attitudinal barriers to appropriate pain management were revealed”.

Delivering better pain management should be a major focus for all paramedics and emergency paramedic services in 2013 and beyond.  From my perspective the key barriers to providing effective prehospital analgesia include:

1.      Paramedics do not adequately assess initial pain
2.      Paramedics do not believe the patient’s reported experience of pain
3.      Physicians limit analgesic options for paramedics
4.      Policy or legal issues preclude prehospital use of analgesia
5.      Patient factors

What should the goal of prehospital analgesia be?

  1. All patients who report pain get analgesia
  2. Patients are pain free on arrival at ED (or patient does not want further analgesia)
  3. Patients are not harmed by prehospital analgesic regimes

How can we prevent prehospital oligoanalgesia?

Paramedics can routinely assess pain in all patients

  • Assessment of pain is poorly done by paramedics – some research reports < 50% of patients
  • It would be hard to find an easier thing to incorporate into your routine clinical practice.  Common pain assessment tools include:

Verbal numerical rating scale (VNRS) (0=no pain, 10=worst possible pain)
Visual analogue scale (VAS) (0 mm = no pain, 100mm = worst possible pain)
Verbal descriptor scale (e.g. Nil, mild, moderate, severe)
Wong-Baker FACES Pain Rating Scale
“Do you have pain? Would you like pain medicine? [see below]”

Paramedics can believe patient reports of pain

  • Pain is a common reason for seeking emergency paramedic services
  • Patients expect the relief of pain
  • Significant harm from believing the patient is unlikely
  • The majority of patient who report pain have pain
  • If the patient reports pain then give analgesia and reassess the patient’s reported experience of pain
  • Patients can have severe pain without significant alterations in vital signs
  • Paramedics can improve the documentation of pain
    • Initial and final pain scores should be mandatory (and truthful)
    • Pain scores must be patient reported (not paramedic reported)
    • Independent assessment of pain at triage would help inform ED management as ED management of pain is also suboptimal
    • Paramedics must participate in research activities and quality improvement initiatives

Medical directors must ensure paramedics have the necessary tools to provide effective analgesia

  •  Agents currently in use in Australia include:

i.     Inhaled:            Methoxyflurane, Entonox

ii.     Parenteral:        Morphine, Fentanyl, Ketamine

iii.     Oral:                 Paracetamol, Ibuprofen, Codeine, Oxycodone

iv.     Intranasal:        Fentanyl, Ketamine

v.     Regional:          Digital blocks, fascia iliaca compartment blocks

Legislative and regulatory barriers to the provision of effective prehospital analgesia must be removed

Research opportunities

  • Effectiveness of routine use of “simple” analgesics for acute pain (e.g. paracetamol) in addition to opiates
  • Effectiveness of oral opiates (e.g. oxycodone) for ambulatory patients in the prehospital setting
  • Strategies to improve paramedic attitudes toward prehospital pain management
  • Role of regional anaesthesia in the prehospital setting

Dr Ed Gentile’s simple, safe, cheap (and fun) approach to management of moderate / severe acute pain for patients < 55 years

Podcast of Dr Gentile’s lecture available at EMCrit at http://emcrit.org/podcasts/gentile-pain/

  1. Administer morphine 0.1 mg/kg i.v.+ diphenhydramine 0.5 mg/kg i.v. (not available in Australia)
  2. 7 minutes later (without any request of the patient) the patient is asked, “Would you like more pain medicine?”
  3. If the answer is yes, the second dose of morphine 0.05 mg/kg i.v. is given
  4. 7 minutes after that (without asking) the patient is offered a third dose and so on….
  5. The protocol repeats until the patient states they have no pain or they don’t want any more pain medicine or the patient is asleep

If 55+ years then Dr Gentile uses 0.05 mg/kg for the initial dose

Advantages of protocol:

  • End point is the patient being completely satisfied
  • Protocol does not discriminate – nor should we
  • Morphine is used as it has the longest half-life of the commonly available opiates
  • Morphine is cheap
  • Seeks to find optimum dose – not the minimum dose

The bottom line

  • Pain is about the patient – after all it is their pain
  • If the patient has pain – give them analgesia
  • The best approach is PATIENT CONTROLLED ANALGESIA…….alternate forms of PCA (paramedic controlled analgesia and physician controlled analgesia) are inferior in the acute setting
  • Little harm will come from sensible analgesic regimes

Do undergraduate paramedic students require prehospital placements?

I gave a presentation on this topic at the Paramedics Australasia conference in Hobart 3 November 2012 to discuss problems with undergraduate students securing prehospital placements.  There are many opportunities for paramedic students to gain the necessary knowledge, skills and experience to prepare them for work as a paramedic – much of which could be gained without prehospital placements at all (and in my view) could better prepare graduates for the reality of life as a paramedic.

Most employers of graduate ‘paramedics’ require a period of “internship” or postgraduate experience prior to recognising graduate paramedics as ‘qualified’ and able to work independently.  Industry is therefore committed to providing graduates with the necessary ‘orientation’ to the out-of-hospital setting where undergraduate learning can be consolidated once they are employed.  I feel that paramedics could benefit greatly by gaining much of their clinical experience in emergency departments embedded within a clinical school delivering medical programs.  This would enable undergraduate paramedic students to be more like undergraduate medical students in their latter years of training.  The emergency department setting mirrors the prehospital setting with respect to acuity and case mix but offers a more concentrated opportunity for learning as each emergency department has a catchment area of typically several ambulance branches.  The emergency department also offers more time for learning and reflection and the opportunity to determine the outcome of the patients prehospital course (what was the diagnosis, what did the paramedics do, would I have done the same – the basis for case based learning).

In this presentation I briefly introduced the defined roles of an emergency physician (according to the Australasian College of Emergency Medicine) and made comparisons between these roles and those of paramedics.  The clinical experiences graduate paramedics need during their training traverse across traditional professional boundaries including medicine, nursing and allied health – this is both a benefit and a challenge of the paramedicine ‘profession’.

Paramedics of the future will need to know more than paramedics now – accelerating the growth of the profession will require new ideas and new perspectives rather than more of the same.  Many challenges lay ahead (including resource implications on emergency departments if such a model was to be adopted).  Embedding paramedic education within clinical schools and considering the out-of-hospital setting (in an acute sense) an extension of the emergency department could make for an interesting model of paramedic education and for paramedic curriculum planning.  Food for thought…download presentation : Undergraduate placements Hobart PA 2012

Prophylactic antiemetics in trauma – the evidence is there!

The evidence base supporting the prehospital use of prophylactic anti-emetics is limited.  Some jurisdictions administer at least one anti-emetic to trauma patients in an effort to prevent nausea and vomiting in this setting.  Whilst there is no good evidence to support the routine administration of metoclopramide when morphine is administered in the acute care setting ( Simpson et al. Emerg Med Australas 2011 23(4): 452-7) there are logical reasons why prophylactic antiemetics are given for patients with trauma. Patients with traumatic injuries typically experience pain and are commonly administered opiate / opioid analgesics both of which are associated with increased rates of nausea and vomiting.  Additionally many trauma patients have their spine immobilised for the transport to hospital which typically includes the fitting of a semi-rigid cervical collar and being secured to a spine board or stretcher. Additionally these patients may have impaired airway reflexes, delayed gastric emptying and motion sickness all contributing to an increased risk of aspiration.

A recent epidemiological study by Easton et al. (Journal of Trauma and Acute Care Surgery 2012, 72(5): 1249-1254) has described the prevalence and risk factors for prehospital nausea and vomiting after trauma….read more

Patient monitoring in the prehospital setting – are ambulances the poor cousin of the health system?


It has always amazed me that the availability of adequate monitoring whilst working as a paramedic is substantially inferior to the monitoring available in other critical care settings.  Why should we accept lower monitoring standards for critically ill patients in the prehospital setting?  All patients should have access to (as appropriate) monitoring of respiratory rate, oxygenation, ECG, intermittent non-invasive blood pressure and carbon dioxide monitoring. Standards for patient monitoring in the prehopsital setting are urgently needed as is the necessary capital funding to make this possible read more

Restoring the focus

Many of you will recall using protocols, procedures and pharmacology (the three Ps). The three Ps should be a reminder of the optimal focus for providers of paramedic care and the leaders of the paramedicine sector – namely patients, paramedics and advancing the profession.  Organisations providing paramedical services need to keep their focus on the optimal care of patients, on the welfare and well-being of their paramedics and on advancing the profession.  All too often however, the focus is on power, politics and process.  This unfortunately comes at the cost of the things that really matter.