Category Archives: PHARM

Prehospital and Retrieval Medicine

Tube tip top tip

I’m not sure what this offers over purpose-built supraglottic airways, but effective ventilation may be achieved after failure of mask ventilation by siting a tracheal tube with its tip in the pharynx and the cuff inflated with 20 mls. The tube ‘is gently inserted 10—14cm, dependent on patient size, or until any resistance is felt, in caudal direction by letting the tip of the tube follow the palate and the posterior pharyngeal wall (in order to place the tip of the tube posterior to the epiglottis)’. As long as the tube tip or Murphy eye is not in the oesophagus, ventilation should be possible. The hand position maintains a jaw thrust while closing the mouth and occluding the nostrils.


BACKGROUND: Mask ventilation occasionally fails. Alternative readily available and simple methods to establish ventilation in these cases are needed.

METHODS: Retrospective description of cases in which a new technique, tube tip in pharynx (TTIP) ventilation, was employed for restoring ventilation in case of failed facemask ventilation during induction of anaesthesia. The technique involves a standard endotracheal tube and can be performed single-handed: A standard endotracheal tube was placed via the mouth with the tip in the pharynx and the cuff was inflated. By placing the fourth and fifth fingers below the ramus of the mandible, the third finger below the lower lip, the second finger above the upper lip and on one side of the nose and the first finger on the other side of the nose, an open airway is restored. Chin lift is inherent in the grip, thus contributing to opening of the airway.

RESULTS: In all four cases of failed mask ventilation the anaesthetist could establish an open airway and subsequent ventilation without the need for an assistant. There were no indications of gastric insufflation.

CONCLUSION: The TTIP technique established ventilation in all four patients after abandoned facemask ventilation. The technique only involves one person and an endotracheal tube and warrants to be included in the armamentarium of anaesthetists. Further prospective studies are needed to refine the technique and delimit its indications.

Tube tip in pharynx (TTIP) ventilation: simple establishment of ventilation in case of failed mask ventilation
Acta Anaesthesiol Scand. 2005 Feb;49(2):252-6

Two hands on the jaw for mask ventilation

Elective surgery patients were anaesthetised with propofol with or without fentanyl and had an oropharyngeal airway placed. They were ventilated with pressure control ventilation via facemask held with a single handed traditional ‘EC clamp’ grip and with a two-handed jaw thrust, and compared. The order in which these two techniques were trialled was randomised. All breaths were delivered with a peak pressure of 15 cm H2O, an inspiratory-to-expiratory ratio of 1:1, at a frequency of 15 breaths per minute. Ventilation was more effective with the two handed technique.
Using a self-inflating bag for resuscitation, this would translate to a two-person technique. Of note in methodology however was use of a ‘standard pillow’ and some emphasis on head extension. Perhaps ventilation would have been more effective with either technique if they had applied the golden rule of ear-to-sternal-notch positioning: a must for effective mask ventilation and successful laryngoscopy.

BACKGROUND: Mask ventilation is considered a “basic” skill for airway management. A one-handed “EC-clamp” technique is most often used after induction of anesthesia with a two-handed jaw-thrust technique reserved for difficult cases. Our aim was to directly compare both techniques with the primary outcome of air exchange in the lungs.
METHODS: Forty-two elective surgical patients were mask-ventilated after induction of anesthesia by using a one-handed “EC-clamp” technique and a two-handed jaw-thrust technique during pressure-control ventilation in randomized, crossover fashion. When unresponsive to a jaw thrust, expired tidal volumes were recorded from the expiratory limb of the anesthesia machine each for five consecutive breaths. Inadequate mask ventilation and dead-space ventilation were defined as an average tidal volume less than 4 ml/kg predicted body weight or less than 150 ml/breath, respectively. Differences in minute ventilation and tidal volume between techniques were assessed with the use of a mixed-effects model.
RESULTS: Patients were (mean ± SD) 56 ± 18 yr old with a body mass index of 30 ± 7.1 kg/m. Minute ventilation was 6.32 ± 3.24 l/min with one hand and 7.95 ± 2.70 l/min with two hands. The tidal volume was 6.80 ± 3.10 ml/kg predicted body weight with one hand and 8.60 ± 2.31 ml/kg predicted body weight with two hands. Improvement with two hands was independent of the order used. Inadequate or dead-space ventilation occurred more frequently during use of the one-handed compared with the two-handed technique (14 vs. 5%; P = 0.013).
CONCLUSION: A two-handed jaw-thrust mask technique improves upper airway patency as measured by greater tidal volumes during pressure-controlled ventilation than a one-handed “EC-clamp” technique in the unconscious apneic person.

A Two-handed Jaw-thrust Technique Is Superior to the One-handed “EC-clamp” Technique for Mask Ventilation in the Apneic Unconscious Person
Anesthesiology. 2010 Oct;113(4):873-9

Easy on the ELM

A first report of thyroid cartilage fracture resulting from laryngoscopy and intubation has been published. An elective surgery patient underwent paralysis with 60 mg rocuronium after which ‘laryngoscopy and intubation attempts with a Macintosh 3 blade, Miller 2 blade, stylet, and vigorous external laryngeal manipulation yielded only Cormack Lehane grade 3 views of the larynx‘. Intubation was eventually achieved with a Glidescope, but it was noted that ‘external laryngeal manipulation was applied as forcefully as the assistant could perform the maneuver‘.
The author suggests the fracture could either have resulted from the external laryngeal manipulation during laryngoscopy or from the rigid curved stylet used with the Glidescope. Whichever it was, their take home advice is sound:

Even during difficult laryngoscopies, gentle manipulations are best

I would add to this – do the ELM yourself – in other words, bimanual laryngoscopy.
Laryngoscopy Complicated by Thyroid Cartilage Fracture
Anesthesiology. 2010 Oct;113(4):993-4

Military trauma care meets standards

Recent recommendations were made regarding trauma care in the UK by the National Confidential Enquiry into Patient Outcome and Death (NCEPOD).
British military physicians at the UK military field hospital, Camp Bastion, Helmand Province, Afghanistan, evaluated their trauma cases against these standards. It is apparent that the trauma care provided to some people in Afghanistan outclasses that delivered within much of the UK.

Military medical teams

Background The National Confidential Enquiry into Patient Outcome and Death (NCEPOD) report on trauma management, published in 2007, defined standards for United Kingdom (UK) hospitals dealing with trauma. This study compared the NCEPOD standards with the performance of a UK military field hospital in Afghanistan. Setting UK military field hospital, Camp Bastion, Helmand Province, Afghanistan.
Materials and methods Data were collected prospectively for all patients fulfilling the trauma team activation criteria during the 3 months of Operation Herrick IXa (from mid October 2008 to mid January 2009) and combined with a retrospective review of prehospital documentation, trauma resuscitation notes, operations notes and transfer notes for these patients.
Results During the study period, there were 226 trauma team activations. Of those patients brought to the medical facility at Camp Bastion by UK assets, 93.7% were accompanied by a doctor with advanced airway skills, although only 6.2% of the patients required such an intervention. Consultants in emergency medicine and anaesthesia were present in 100% of cases and were directly involved (in either leading the team or performing airway management) in 63.5% and 77.6% of cases respectively. Of those patients requiring operative intervention, 98.1% had this performed by a consultant surgeon. Of those patients requiring CT, 93.6% of cases had this performed within 1 h of arrival.
Conclusions Trauma patients presenting to the medical facility at Camp Bastion during Operation Herrick IXa, irrespective of their nationality or background, received a high standard of medical care when compared with the NCEPOD standards

National Confidential Enquiry into Patient Outcome and Death recommendations
Pre-hospital care
All agencies involved in trauma management, including emergency medical services, should be integrated into the clinical governance programmes of a regional trauma service. Airway management in trauma patients is often challenging, and the pre-hospital response for these patients should include someone with the skill to secure the airway, (including the use of rapid sequence intubation), and maintain adequate ventilation.
Hospital reception
A trauma team should be available 24 h a day, 7 days a week. This is an essential part of an organised trauma response system. A consultant must be the team leader for the management of the severely injured patient.
Airway and breathing
The current structure of prehospital management is insufficient. There is a high incidence of failed intubation and a high incidence of patients arriving at hospital with a partially or completely obstructed airway. Change is urgently required to provide a system that reliably provides a clear airway with good oxygenation and control of ventilation. This may be through the provision of personnel with the ability to provide anaesthesia and intubation in the prehospital phase or through the use of alternative airway devices.
Circulation
Trauma laparotomy is extremely challenging and requires consultant presence within the operating theatre. If CT is to be performed, all necessary images should be obtained at the same time, and routine use of head-to-toe scanning is recommended in the adult trauma patient if no indication for immediate intervention exists.
Head injuries
Patients with severe head injury should have a CT of the head performed as soon as possible after admission and within 1 hour of arrival at the hospital. All patients with severe head injury should be transferred to a neurosurgical critical care centre irrespective of the requirement for surgical intervention.
Transfers
There should be standardised transfer documentation of patient details, injuries, results of investigations and management, with records kept at the dispatching and receiving hospitals.
A comparison of civilian (National Confidential Enquiry into Patient Outcome and Death) trauma standards with current practice in a deployed field hospital in Afghanistan.
Emerg Med J 2011;28:310-312

Intranasal ketamine analgesia

I published a case report in the EMJ highlighting the use of intranasal ketamine in a pre-hospital paediatric burns case.
The lad had nasty scalds but did not need iv fluids and had no other indications for an iv line. The vigorous first aid had rendered him cold and veinless and an intraosseous would have been overkill. Ketamine was perfect for the job and Ambulance Service New South Wales paramedics carry a mucosal atomisation device (MAD) for the administration of i.n. fentanyl. I used the MAD to adminster 0.5 mg/kg ketamine, but there is a dead space in the device (0.1 ml) that probably resulted in actual delivery of 0.25mg/kg. This gave great analgesia and compliance enabling us to painlessly apply polyethylene film to the burns.
I received the following email from TIm Wolfe, the inventor of the MAD nasal (reproduced with permission):

Cliff,
Nice contribution to the literature. There is a lot of interest in IN ketamine in these lower doses to treat pain but not cause sedation. You eluded to the military interest and the hospice interest. I think your insights for EMS are also cutting edge – hopefully this will lead others to design a larger trial.
Thanks
Tim Wolfe, MD

More information on the use of intranasal medication is available at www.intranasal.net. I have no conflicts of interest to declare.
Case report: prehospital use of intranasal ketamine for paediatric burn injury
Emerg Med J. 2011 Feb 3. [Epub ahead of print]

The lottery of pre-hospital physicians

In contrast to numerous other European nations, physicians with critical care skills do not consistently form part of the emergency pre-hospital system in the UK. My colleagues and I described the level of cover provided to patients in England, Wales and Northern Ireland, now available as an open access article online.
The BMJ’s press release is headed: ‘Critical care outside hospital ‘incomplete, unpredictable, and inconsistent’ across UK‘, a statement that has captured the interest of some media outlets, including the first place you would look for health news: bigsoccer.com.

Pre-hospital physician-based critical care provision. (A) Daylight hours. (B) Hours of darkness.

 

Background Every day throughout the UK, ambulance services seek medical assistance in providing critically ill or injured patients with pre-hospital care.
Objective To identify the current availability and utilisation of physician-based pre-hospital critical care capability across England, Wales and Northern Ireland.
Design A postal and telephone survey was undertaken between April and December 2009 of all 13 regional NHS ambulance services, 17 air ambulance charities, 34 organisations affiliated to the British Association for Immediate Care and 215 type 1 emergency departments in England, Wales and Northern Ireland. The survey focused on the availability and use of physician-based pre-hospital critical care support.
Results The response rate was 100%. Although nine NHS ambulance services recorded physician attendance at 6155 incidents, few could quantify doctor availability and utilisation. All but one of the British Association for Immediate Care organisations deployed ‘only when available’ and only 45% of active doctors could provide critical care support. Eleven air ambulance services (65%) operated with a doctor but only 5 (29%) operated 7 days a week. Fifty-nine EDs (27%) had a pre-hospital team but only 5 (2%) had 24 h deployable critical care capability and none were used regularly.
Conclusion There is wide geographical and diurnal variability in availability and utilisation of physician-based pre-hospital critical care support. Only London ambulance service has access to NHS-commissioned 24 h physician-based pre-hospital critical care support. Throughout the rest of the UK, extensive use is made of volunteer doctors and charity sector providers of varying availability and capability.

Availability and utilisation of physician-based pre-hospital critical care support to the NHS ambulance service in England, Wales and Northern Ireland
Emerg Med J. 2011 Mar 21. [Epub ahead of print] Open Access Full Text

Suspension syncope

Loss of consciousness can occur when a patient is suspended in a harness – ‘suspension syncope’, probably due to factors that include venous pooling in the lower limbs. An evidence based review of this entity was carried out:

The possibility of a fall into rope protection and subsequent suspension exists in some industrial situations. The action to take for the first aid management of rescued victims has not been clear, with some authors advising against standard first aid practices. To clarify the medical evidence relating to harness suspension the UK Health and Safety Executive commissioned an evidence-based review and guideline. Four key questions were posed relating to the incidence, circumstances, recognition and first aid management of the medical effects of harness suspension. A comprehensive literature search returned 60 potential papers with 29 papers being reviewed. The Scottish Intercollegiate Guideline Network (SIGN) methodology was used to critically review the selected papers and develop a guideline. A stakeholders’ workshop was held to review the evidence and draft recommendations. Nine papers formed the basis of the guideline recommendations. No data on the incidence of harness suspension syncope were found. Presyncopal symptoms or syncope are thought to occur with motionless suspension as a consequence of orthostasis leading to hypotension. There was no evidence of any other pathology, despite this being hypothesised by others. No evidence was found that showed the efficacy or safety of positioning a victim in a semirecumbent position. In any case of harness suspension, the standard UK first aid guidance for recovery of a semiconscious or unconscious person in a horizontal position should be followed. Other recommendations included areas for further research and proposals for standard data collection on falls into rope protection.

Harness suspension and first aid management: development of an evidence-based guideline
Emerg Med J 2011;28:265-268

Which cardiac arrest survivors have a positive angio?

A retrospective study of out-of-hospital cardiac arrest patients attended by a French pre-hospital system was performed to assess the predictive factors for positive coronary angiography.

OBJECTIVES: Coronary angiography is often performed in survivors of out-of-hospital cardiac arrest, but little is known about the factors predictive of a positive coronary angiography. Our aim was to determine these factors.
METHODS: In this 7-year retrospective study (January 2000-December 2006) conducted by a French out-of-hospital emergency medical unit, data were collected according to Utstein style guidelines on all out-of-hospital cardiac arrest patients with suspected coronary disease who recovered spontaneous cardiac activity and underwent early coronary angiography. Coronary angiography was considered positive if a lesion resulting in more than a 50% reduction in luminal diameter was observed or if there was a thrombus at an occlusion site.
RESULTS: Among the 4621 patients from whom data were collected, 445 were successfully resuscitated and admitted to hospital. Of these, 133 were taken directly to the coronary angiography unit, 95 (71%) had at least one significant lesion, 71 (53%) underwent a percutaneous coronary intervention, and 30 survived [23%, 95% confidence interval (CI): 16-30]. According to multivariate analysis, the factors predictive of a positive coronary angiography were a history of diabetes [odds ratio (OR): 7.1, 95% CI: 1.4-36], ST segment depression on the out-of-hospital ECG (OR: 5.4, 95% CI: 1.1-27.8), a history of coronary disease (OR: 5.3, 95% CI: 1.4-20.1), cardiac arrest in a public place (OR: 3.7, 95% CI: 1.3-10.7), and ventricular fibrillation or ventricular tachycardia as initial rhythm (OR: 3.1, 95% CI: 1.1-8.6).
CONCLUSION: Among the factors identified, diabetes and a history of coronary artery were strong predictors for a positive coronary angiography, whereas ST segment elevation was not as predictive as expected.

Predictive factors for positive coronary angiography in out-of-hospital cardiac arrest patients
Eur J Emerg Med. 2011 Apr;18(2):73-6

Pre-hospital physician triage

A Swiss study examined the on site triage decision making of pre-hospital emergency physicians. Dispatch of the physicians was coordinated by trained nurses or paramedics.

OBJECTIVE: Accurate identification of major trauma patients in the prehospital setting positively affects survival and resource utilization. Triage algorithms using predictive criteria of injury severity have been identified in paramedic-based prehospital systems. Our rescue system is based on prehospital paramedics and emergency physicians. The aim of this study was to evaluate the accuracy of the prehospital triage performed by physicians and to identify the predictive factors leading to errors of triage.
METHODS: Retrospective study of trauma patients triaged by physicians. Prehospital triage was analyzed using criteria defining major trauma victims (MTVs, Injury Severity Score >15, admission to ICU, need for immediate surgery and death within 48 h). Adequate triage was defined as MTVs oriented to the trauma centre or non-MTV (NMTV) oriented to regional hospitals.
RESULTS: One thousand six hundred and eighti-five patients (blunt trauma 96%) were included (558 MTV and 1127 NMTV). Triage was adequate in 1455 patients (86.4%). Overtriage occurred in 171 cases (10.1%) and undertriage in 59 cases (3.5%). Sensitivity and specificity was 90 and 85%, respectively, whereas positive predictive value and negative predictive value were 75 and 94%, respectively. Using logistic regression analysis, significant (P<0.05) predictors of undertriage were head or thorax injuries (odds ratio >2.5). Predictors of overtriage were paediatric age group, pedestrian or 2 wheel-vehicle road traffic accidents (odds ratio >2.0).
CONCLUSION: Physicians using clinical judgement provide effective prehospital triage of trauma patients. Only a few factors predicting errors in triage process were identified in this study.

Accuracy of prehospital triage of trauma patients by emergency physicians: a retrospective study in western Switzerland
Eur J Emerg Med. 2011 Apr;18(2):86-93

Supplemental oxygen decreases LV perfusion in volunteers

Oxygen therapy in normoxic acute coronary syndrome patients is controversial, and a previous systematic review cautioned against it in uncomplicated MI. A volunteer study using cardiac imaging demonstrates the effects of supplemental oxygen on coronary blood flow.
 

OBJECTIVES: Oxygen (O2) is a cornerstone in the treatment of critically ill patients, and the guidelines prescribe 10-15 l of O2/min even to those who are initially normoxic. Studies using indirect or invasive methods suggest, however, that supplemental O2 may have negative cardiovascular effects. The aim of this study was to test the hypothesis, using noninvasive cardiac magnetic resonance imaging, that inhaled supplemental O2 decreases cardiac output (CO) and coronary blood flow in healthy individuals.
METHODS: Sixteen healthy individuals inhaled O2 at 1, 8 and 15 l/min through a standard reservoir bag mask. A 1.5 T magnetic resonance imaging scanner was used to measure stroke volume, CO and coronary sinus blood flow. Left ventricular (LV) perfusion was calculated as coronary sinus blood flow/LV mass.
RESULTS: The O2 response was dose-dependent. At 15 l of O2/min, blood partial pressure of O2 increased from an average 11.7 to 51.0 kPa with no significant changes in blood partial pressure of CO2 or arterial blood pressure. At the same dose, LV perfusion decreased by 23% (P=0.005) and CO decreased by 10% (P=0.003) owing to a decrease in heart rate (by 9%, P<0.002), with no significant changes in stroke volume or LV dimensions. Owing to the decreased CO and LV perfusion, systemic and coronary O2 delivery fell by 4 and 11% at 8 l of O2/min, despite the increased blood oxygen content.
CONCLUSION: Our data indicate that O2 administration decreases CO, LV perfusion and systemic and coronary O2 delivery in healthy individuals. Further research should address the effects of O2 therapy in normoxic patients.

Effects of oxygen inhalation on cardiac output, coronary blood flow and oxygen delivery in healthy individuals, assessed with MRI
European Journal of Emergency Medicine 2011, 18:25–30