Rate of Decline in Oxygen Saturation at Various Pulse Oximetry Values with Prehospital Rapid Sequence Intubation

Daniel P. Davis;  James Q. Hwang; James V. Dunford

This study set out to examine the rate of SpO2 decline at various pulse oximetry values during pre-hospital rapid sequence intubation, and identify a threshold below which active BVM should be performed during prehospital RSI.

Traumatic brain injury patients undergoing prehospital RSI were included. The timeperiod from the highest to the lowest pre-intubation SpO2 was selected. The mean rate of SpO2 decline was calculated and then used to define a hypothetical desaturation curve. The rate of desaturation to hypoxaemia (SpO2 <90%) was then defined for RSI initiated at each SpO2 value.

Results show that lower SpO2 values were associated with a faster rate of SpO2 decline with an inflection point occurring at 93%. The incidence of desaturation to hypoxaemia was much higher when RSI was initiated with SpO2 <93% (100%) compared with SpO2 >93% (6%).

In conclusion, the rate of SpO2 decline increases as the SpO2 decreases. RSI attempted at SpO2 below 93% is almost always associated with hypoxaemia, suggesting that BVM should be used in these patients prior to intubation.

Prehosp Emerg Care. 2008 Jan-Mar;12(1):46-51

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Pleural decompression and drainage during trauma reception and resuscitation

M. Fitzgerald, C.F. Mackenzie, S. Marasco, R. Hoyle and T. Kossmann

This review looks at the different methods of pleural decompression and drainage during the initial hospital treatment of adult trauma patients when it is indicated for haemodynamically unstable patients with clinical signs of pneumothorax or haemothorax.

Key findings of this review are that:

1. Needle thoracocentesis is an unreliable means of decompressing the chest of an unstable patient and should only be used as a technique of last resort.
2. Blunt dissection and digital decompression through the pleura is the essential first step for pleural decompression, as decompression of the pleural space is a primary goal during reception of the haemodynamically unstable patient with a haemothorax or pneumothorax. Drainage and insertion of a chest tube is a secondary priority.
3. Techniques to prevent tube thoracostomy (TT) complications include aseptic technique, avoidance of trocars, digital exploration of the insertion site and guidance of the tube posteriorly and superiorly during insertion.
4. Whenever possible, blunt thoracic trauma patients should undergo definitive CT imaging after TT to check for appropriate tube position.

Injury. 2008 Jan;39(1):9-20

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Needle Thoracostomy in the Treatment of a Tension Pneumothorax in Trauma Patients: What Size Needle?

Zengerink, Imme MD; Brink, Peter R. MD, PhD; Laupland, Kevin B. MD, MSc, FRCPC; Raber, Earl L. MD, FRCPC; Zygun, Dave MD, MSc, FRCPC; Kortbeek, John B. MD, FRCSC, FACS

Tension pneumothorax requires immediate decompression with needle thoracostomy. According to ATLS teaching, this is performed in the 2nd intercostal space, mid-clavicular line using a 5cm needle.

Previous studies have demonstrated high failure rates with this method (up to 40%) and recent case reports have suggested that this could be due to insufficient needle length.

This study set out to analyse the average chest wall thickness at the 2nd intercostal space in the mid-clavicular line in a trauma patient and to evaluate the required needle length to perform successful needle thoracostomy for tension pneumothorax.

604 males and 170 females who underwent a CT scan which included the thorax for trauma were examined. Chest wall thickness averaged 3.50cm at the left 2nd ICS and 3.51cm on the right. The mean chest wall thickness was significantly greater for women than men. Over 10% of men and over 25% of women had a chest wall thickness greater than 4.5cm.

In conclusion, a 5cm needle may not penetrate the chest wall in a substantial number of cases depending upon age and gender.

J Trauma. 2008 Jan;64(1):111-4

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Emergency Department Thoracotomy: Still Useful After Abdominal Exsanguination?

Seamon, Mark J. MD; Pathak, Abhijit S. MD; Bradley, Kevin M. MD; Fisher, Carol A. BA; Gaughan, John A. PhD; Kulp, Heather RN, MPH; Pieri, Paola G. MD; Santora, Thomas A. MD; Goldberg, Amy J. MD

The current published evidence regarding emergency department thoracotomy (EDT) for anything other than cardiac wounds describes poor patient outcomes. This study examines the use of EDT for patients with exsanguinating abdominal haemorrhage.

A retrospective study identified 50 patients who underwent EDT for abdominal exsanguination over a 6 year period. The primary endpoint was neurologically-intact hospital survival.

These patients were largely young males suffering from gunshot wounds (98%). 78% presented with signs of life, and GCS was depressed (mean 4.2). Eight patients survived to discharge neurologically intact. All of these had major abdominal vascular (75%) or severe liver (25%) injuries and all required massive blood transfusion (mean 28.6 +/- 17.3 units) and extended intensive care stay (mean 36.3 days).

This study concludes that despite critical injuries, 16% of patients survived to discharge neurologically intact after EDT for exsanguinating abdominal injury.

World J Surg. 2008 Jan 26 [Epub ahead of print]

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Delayed Time to Defibrillation after In-Hospital Cardiac Arrest

Paul S. Chan, M.D., Harlan M. Krumholz, M.D., Graham Nichol, M.D., M.P.H., Brahmajee K. Nallamothu, M.D., M.P.H., and the American Heart Association National Registry of Cardiopulmonary Resuscitation Investigators

The latest resuscitation guidelines advocate defibrillation after an in-hospital cardiac arrest within 2 minutes. This study set out to examine whether delayed access to defibrillation has an impact upon patient morbidity and mortality.

Using data from 6789 patients (from 369 hospitals using the National Registry of Cardiopulmonary Resusciation in the USA) who had a cardiac arrest in-hospital due to ventricular fibrillation or pulseless ventricular tachycardia, the association between delayed defibrillation (>2 minutes) and survival to discharge was examined.

Delayed defibrillation occurred in 30.1% of cases. Associated factors included non-cardiac admitting diagnosis, occurrence in an unmonitored bed and out-of hours. This delay led to significantly lower probability of surviving to discharge (22.2% compared with 39.3% when defibrillation was not delayed). With increasing time to defibrillation is a trend towards lower rates of survival.

N Engl J Med. 2008 Jan 3;358(1):9-17

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Supplementation of pre-oxygenation in morbidly obese patients using nasopharyngeal oxygen insufflation

S. Baraka, SK. Taha, SM. Siddik-Sayyid, GE. Kanazi, MF. El-Khatib, CM. Dagher, J-MA. Chehade, FW. Abdallah and RE. Hajj

Studies have shown that apnoea following induction of anaesthesia in morbidly obese patients may result in a rapid decrease in oxygen saturation.

This study compares pre-oxygenation alone with pre-oxygenation followed by nasopharyngeal oxygen insufflation during apnoea following induction. Thirty four patients undergoing gastric bypass or gastric band surgery were randomised into the two groups. Time from onset of apnoea until SpO2 fell to 95% was compared.

In the group receiving pre-oxygenation alone, SpO2 fell to 95% in 145 seconds with a significant negative correlation between time to desaturation and BMI.
In the study group, SpO2­ was maintained in 16/17 patients at 100% for 4 minutes, when apnoea was terminated.

In conclusion, nasopharygeal oxygen insufflation following pre-oxygenation in morbidly obese patients delays the onset of desaturation during induction of anaesthesia.

Anaesthesia. 2007 Aug;62(8):769-73

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Sedation in the emergency department

Smally, Alan J; Nowicki, Thomas Anthony

The use of sedation outside the anaesthetic room is increasing. Moderate-to-deep sedation is used with greater frequency in the emergency department for a number of reasons with the most common indication being orthopaedic.

This review examines the literature presented in the previous year in this area of practice. It found that procedural sedation and analgesia is performed using propfol, etomidate, midazolam, fentanyl, ketamine and nitrous oxide. Cardiac monitoring, pulse oximetry and capnography are used but often without evidence for need. Complications are higher in prospective than retrospective studies, although clinically important complications are uncommon.

Curr Opin Anaesthesiol. 2007 Aug;20(4):379-83

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Prehospital Procedures Before Emergency Department Thoracotomy: "Scoop and Run" Saves Lives

Seamon, Mark J. MD; Fisher, Carol A. BA; Gaughan, John PhD; Lloyd, Michael MS, RN; Bradley, Kevin M. MD; Santora, Thomas A. MD; Pathak, Abhijit S. MD; Goldberg, Amy J. MD

Do prehospital procedures have a negative impact on critically injured penetrating trauma patients?

The role of prehospital care in the management of acutely injured patients is rapidly evolving. This study, however, set out to test the hypothesis that survival of critically injured penetrating trauma patients requiring thorocotomy would be improved if procedures were restricted until arrival in the emergency department.

A retrospective review of 180 penetrating trauma patients who underwent emergency department thorocotomy was performed. These were divided into two groups based on method of arrival at the emergency department – by emergency medical services (88 patients) or by police / private vehicle (92).

The groups were similar in demographics. Of the EMS-transported group, 8% survived to discharge compared with 17.4% of those arriving by police / private vehicle. The main difference between these groups was that the police / private vehicle group underwent no prehospital procedures, whereas the EMS group had a total of 137 procedures performed.

Multivariate logistic regression analyses identify these prehospital procedures as the sole independent predictor of mortality, with each procedure increasing the patient mortality by 2.63 times.

This study concludes that in this distinct population of crticially injured penetrating trauma patients, the performance of prehospital procedures has a negative effect on survival after emergency department thorocotomy.

J Trauma. 2007 Jul;63(1):113-20

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The Predictive Value and Appropriate Ranges of Prehospital Physiological Parameters for High-Risk Injured Children

Newgard, Craig D. MD, MPH; Cudnik, Michael MD; Warden, Craig R. MD, MPH; Hedges, Jerris R. MD, MS

Which prehospital observations are best at identifying high risk children?

A retrospective cohort analysis of injured children under the age of 14 years was carried out in the USA, including children transported to hospital to emergency medical services between 1998 and 2003. Prehospital observations were analysed, including GCS, systolic blood pressure, respiratory rate, heart rate and airway intervention.

“High risk” children were defined as those dying whilst in hospital, requiring major non-orthopaedic surgery, requiring intensive care unit stay >2 days or ISS >16.

After analysing 3877 children, of which 1111 (29%) were high risk, prehospital GCS was the variable of greatest importance in identifying high risk children. Second to this was airway intervention, and then respiratory rate.

Therefore, prehospital GCS and respiratory compromise were the most important observations in identifying high risk injured children.

Pediatr Emerg Care. 2007 Jul;23(7):450-6

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The epidemiology of fractures in children

Louise Rennie, Charles M. Court-Brown, Jacqueline Y.Q. Mok and Thomas F. Beattie
This is a retrospective study of all paediatric fractures presenting to a Scottish hospital in 2000.

The incidence of fractures in the paediatric population was 20.2/1,000/year with 61% occurring in males. The incidence of fractures increases with age. The commonest cause of a fracture is a fall from <1 metre.

In terms of different injuries, the majority involve the upper limb. Lower limb fractures are mostly associated with twisting injuries and road traffic accidents.

Injury. 2007 Aug;38(8):913-22. Epub 2007 Jul 12

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Emergency medicine in modern Europe

Thomas Fleischmann and Gordian Fulde

Emergency medicine has evolved into two distinct approaches. The Anglo-American system with skilled emergency departments and prehospital paramedic-led emergency medical service; and the Franco-German system of high-developed prehospital emergency physician service but only basic hospital-based emergency medicine. The gap between these is now rapidly closing.

Factors influencing the closing of this gap include the recognition of emergency medicine as a specialty, a specialist training programme, the presence of academic centres of excellence, and the professional organisation of emergency physicians.

The European Society for Emergency Medicine has been working to create a curriculum for emergency medicine for pan-European adoption, which is expected in late 2007, comprising a 5 year training programme.

This paper describes the present situation with emergency medicine in Europe and suggests what the future may hold.

Emerg Med Australas. 2007 Aug;19(4):300-2

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Prehospital anaesthesia in the UK: position statement

David Lockey and Keith Porter

Anaesthesia is carried out in the prehospital environment by a small number of individuals in the United Kingdom. This position statement assesses what is required of these individuals and stresses the important requirement for patient safety systems.

EMJ 2007;24:437-438

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The effect of cricoid pressure on intubation facilitated by the gum elastic bougie

U. McNelis, A. Syndercombe, I. Harper and J. Duggan

Does cricoid pressure on intubation influence its success?

Tracheal tube impingement is common when using a gum elastic bougie and a 90° anti-clockwise rotation of the tube usually relieves it. This study investigates the effect of cricoid pressure on gum elastic bougie-facilitated intubation in 120 patients.
Impingement occurred in 38% of cases with sham cricoid pressure and 60% of case with 30N cricoid pressure. Ninety degree anti-clockwise rotation of the tube was successful in all cases with sham cricoid pressure and 89% of those with 30N cricoid pressure.
This study concludes that although impingement is common, 90° anti-clockwise rotation is highly effective in solving this problem.

Anaesthesia, 2007 May;62(5):456-9

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A history of mechanical devices for providing external chest compressions

Russell Harrison-Paul

This article provides an in-depth overview of some of the mechanical devices which have been developed over the past 45 years in order to deliver external chest compressions. Despite their existence over this period of time, they have failed to become a regular part of resuscitation practice and the article suggests reasons for this.

Resuscitation 2007 Jun;73(3):330-6

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The Accuracy of Thoracic Ultrasound for Detection of Pneumothorax is not Sustained Over Time: a Preliminary Study

Dente, Christopher J; Ustin, Jeffrey; Feliciano, David V; Rozycki, Grace S; Wyrzykowski, Amy D; Nicholas, Jeffrey M; Salomone, Jeffrey P; Ingram, Walter L

Does ultrasound remain accurate in the diagnosis of pneumothorax in patients with a thorocostomy?

This study set out to examine all hospitalised patients with a thorocostomy placed to treat a traumatic pneumothorax. Each patient underwent serial daily surgeon-performed ultrasound scans. The results of these were compared with concomitant chest x-ray findings.

Results show that in the first 24 hours, ultrasound is 100% accurate in diagnosing pneumothoraces. After 24 hours, however, sensitivity fell to 55%, specificity to 70%, giving an overall accuracy of 65%.

Therefore, although initially highly accurate, this accuracy is not sustained over time, perhaps due to the formation of intrapleural adhesions.

J Trauma 2007 Jun;62(6):1384-9

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Emergency Department Staff Preparedness for Mass Casualty Events Involving Children

Michal Rassin PhD, Miri Avraham MA, Anat Nasi-Bashari MA, Sigalit Idelman BA, Yaniv Peretz BA, Shani Morag MA, Dina Silner MA, and Gali Weiss MA

Mass casualty incidents are increasingly common, often as a result of terrorism. How prepared are individuals and hospitals for incidents involving children?

This article from Israel examines preparedness for mass casualty incidents involving children – something that is already a reality in parts of Israel and could at any time occur elsewhere as a result of terrorism, natural disaster or public transportation accident.

An initial literature review highlighted both a lack of existing training programs and also lack of certainty on the part of the healthcare providers who may have to deal with these events.

Using a questionnaire, 104 physicians working at an emergency hospital in Israel were surveyed. The study found that preparedness levels for incidents involving children were low and that individuals were concerned about their ability to cope mentally and have the knowledge and skills required if the circumstances arose.

Disaster Manag Response 2007 Apr-Jun;5(2):36-44

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Pathophysiology of traumatic brain injury

C Werner and K Engelhard

A thorough understanding of the pathophysiology of traumatic brain injury is essential for adequate treatment. The target of treatment if the secondary damage which is influenced by changes in cerebral perfusion, cerebrovascular autoregulation, metabolic function and cerebral hypoxia.

This article discusses the pathophysiology of traumatic brain injury and the various mechanisms associated with secondary brain injury, including the therapeutic options on offer.

Br J Anaesth 2007 Jul;99(1):4-9

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Effects of Mannitol Bolus Administration on Intracranial Pressure, Cerebral Extracellular Metabolites, and Tissue Oxygenation in Severely Head-Injured Patients

Sakowitz, Oliver W; Stover, John F; Sarrafzadeh, Asita S; Unterberg, Andreas W; Kiening, Karl L.
 
Although osmotic agents are widely-used to lower elevated intracranial pressure (ICP), little is known about their cerebral effects in patients with traumatic brain injury (TBI)

The authors set out to examine whether mannitol, prescribed after TBI to lower moderately-raised ICP, improves cerebral metabolism and oxygenation.
 
Conclusions: at ICP of ≤30mmHg [4kPa], mannitol does not affect cerebral oxygenation, but may cause transient osmotic dehydration.
 
J Trauma, 2007;62(2):292-298

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