Constant Jet Lag in Emergency Medicine

Emergency Medicine is high risk speciality that brings a lot of stress with it and maximum burn out rates among its providers. A major reason why people quit EM is due to the rotating shifts. And as we turn older, it gets difficult to cope up with this ever changing shift work schedule. Many of us suffer from this under appreciated problem of shift work disorder. Rather than accepting Shift Work Disorder (SWD) as something that always comes along with EM, we should find out ways and learn how to cope up with it. 

What is Shift Work Disorder?

SWD is clinically recognized condition that develops in some individuals who work at night, start work early in the morning (4am-7am), or work according to a rotating shift schedule. SWD consists of a constant or recurrent pattern of sleep interruption that results in difficulty sleeping when you should sleep or excessive sleepiness when you are supposed to stay awake and alert. 

Problems that might occur with Shift workers:

Medical errors 

Disturbed circadian rhythm

Risk of peptic ulcer disease

Cardiovascular disease
Hypertension

Chronic Fatigue, insomnia

High Divorce rate

Substance abuse and Depression

Immunosuppression

Fertility issues

Poor dietary choices

Thyroid issues

Most circadian rhythms have both an endogenous component (regulated by suprachiasmatic nucleus of the hypothalamus) and an exogenous component. The exogenous component is composed of various time clues called zeitgebers. One of the most powerful zeitgebers is the light/dark cycle (e.g. Sun). Other examples of zeitgebers can be food, television, exercise, caffeine, sports. We can synchronise with these zeitgebers and give the right cues to our body to promote wakefulness/sleep. 

For instance , prior to starting a night shift, exercising OR eating typical breakfast foods OR exposure to bright light gives subtle clues to your body that it is time to get up and start the day. Similarly, having a cup of coffee, bright light exposure and exercising after a night shift is a bad idea!!

Few Strategies for setting up night shifts:

1. If you can work it out, then the best way is to do a stretch of nights for 6-8 weeks once in a year. This way you would need to change your sleep cycle only twice a year (not every week!). No meetings/academic sessions after night shifts.

2. Casino Shifts: With casino shifts, one long night shift is cut into two short shifts, from 10pm-4am and from 4am to 10am. With these shifts the "early risers" turn up for the 4am shift and people who prefer to sleep late in the night leave by 4am. Both these groups can then continue their next day normally without affecting their social liv. Some people like and prefer to work like this.

3. Avoid doing >2-3 nights in a row.

Shift Length: Some physicians prefer shorter shifts (6-8hrs) and some like to stick to the 12hr shifts. With shorter shifts, it is found that physicians are more alert and respond better while with the two 12hr shifts, you get more days off per week. 

Here are some things that we can do to cope up with Shift work:

1. Education and Awareness (For shift workers as well as their families)

2. Individual Strategies

Prior to night shift, To promote wakefullness:

• Make sure you get some sleep during the day time (Never start a night shift in sleep deprivation)
• Exercise in the evening 
• Expose yourself to bright light 
• Having more staff overnight is beneficial
• Have dedicated breaks, with coffee and high protein foods

During night shift, To stay alert 

• Keep your naps short (<30 minutes)
• Stay exposed to bright light
• Have a high carbohydrate/protein snack to keep you awake
• Caffeine (only during the first half of shift)

After night shift, To promote sleep:

• Use sunglasses while travelling back home to avoid bright light exposure
• Use ear plugs/eye protectors, black curtains 
• Make sure that your room temperature is comfortable 
• Keep your kids and pets away to avoid disturbances while you are asleep (Noisy environments cause sleep fragmentation)
• Have a dedicated quiet area to sleep
• Avoid fatty/ spicy food before you sleep
• Avoid early morning caffeine 
• Switch off your phone and try using an answering machine

Shift schedule should be made by someone who understands SWD

ACEP endorses the following principles:

• Scheduling isolated night shifts or relatively long sequences of night shifts is recommended. 
• Overly long shifts or inordinately long stretches of shifts on consecutive days should be avoided whenever possible. In most settings, shifts should last twelve hours or less. Schedulers should take into consideration the total number of hours worked by each practitioner and the intervals of time off between shifts. 
• ACEP strongly recommends that practitioners have regularly scheduled periods of at least 24 hours off work. 
• Rotating shifts in a clockwise manner (day to evening to night) is preferred.
• Night shift workers' schedules must be designed carefully to provide for anchor sleep periods, and those workers' daytime responsibilities should be held to an absolute minimum. 
• Groups should consider various incentives to compensate those working predominantly night shifts. 
• Schedules for emergency physicians should take into account factors such as ED volume, patient acuity levels, non-clinical responsibilities, and individual physician's age. 
• A place to sleep before driving home after night shifts should be provided.

3. Pharmacolgy

To promote sleep:

BZDs (addiction, side effects)

Zolpidem is better than BZDs

Melatonin: take few hours prior to sleep, dose: 0.5-5mg

Stimulants to promote wakefullness:

Modafinil (Dopamine reuptake inhibitor, Also activates Glutamate and inhibits GABA)

Caffeine: Too much leads to agitation, tolerance overtime and withdrawal. Avoid taking caffeine during the second half of your shift.
Energy drinks: Caffeine + sugar 

Key Points

• Educate your family and colleagues about Shift Work Disorder
• Learn how to play with the zeitgebers
• Do not overly on medications
• Consider incentives for those who work the unpopular night shifts 

References:

1.Haney Mallemat - Shift Work Disorder: http://www.emedhome.com/cme_infocus.cfm

2.https://www.acep.org/Clinical---Practice-Management/Emergency-Physician-Shift-Work/

3.Boggild H, Knutsson A. Shift work, risk factors and cardiovascular disease. Scand J Work

Environ Health. 1999;25:85-99.

4.http://www.acep.org/Clinical---Practice-Management/Circadian-Rhythms-and-Shift-Work/

5.http://www.gru.edu/mcg/clerkships/em/documents/shiftwork.pdf

6.http://cjem-online.ca/v15/s1/the-impact-of-“casino-shifts”-on-emergency-physician-productivity

Where do we measure ST elevation?

This was just another ACS for me, but it is really amazing how "Dr. Mattu" took out some great teaching points from it. 

Check out this resource for more EM/ECG stuff..
https://ecgweekly.com

Capnography beyond ROSC

What is Capnography?

It is a non-invasive technique where CO2 is analysed continuously, in the gases entering and leaving the lungs. Look at it like a non-invasive way of estimating the PaCO2. Normal ETCO2 ranges between 35-45mmHg.

Different ways of estimating ETCO2:

1. Waveform capnography (Quantitative): When ETCO2 is graphically displayed and analysed quantitatively (real time quantitative waveform as depicted below). Capnograph is the device that measures and displays the waveform. It gives us a number i.e very close to the PaCO2 (typically underestimates PaCO2 by 5mmHg in healthy adults). Therefore, a high ETCO2 is almost always associated with hypercapnia. 

Normal Capnograph (Adults)

2. Capnometry (Quantitative): When only the numerical value is displayed without the waveform.

                         

3. Qualitative: Does not tell us one fixed number instead gives a range of ETCO2 using the calorimetric device. Ex. 21-30mmHg. Hence, utility is limited to ET tube placement verification.

Calorimeter device

How is it different from SpO2?

SpO2 measures O2 saturation in the blood whereas ETCO2 measures CO2 in the airway. ETCO2 reflects the elimination of CO2 by the lungs and thus paints an immediate picture of patient's condition on the monitor, in contrast to SpO2 that remains normal for several minutes (even when you hold your breath).

SpO2 and ETCO2                             

When interpreting ETCO2, look at both, the numeric value as well as the waveform. If you look only at the numeric value, this is like only looking at the heart rate without the ECG wave pattern!

Normal ETCO2 waveform:

Phase I aka Dead space ventilation/ Inspiratory baseline: Beginning of exhalation, no gas exchange here. There is almost no CO2 in airway during inspiration, so baseline is normally zero.

Phase II aka Ascending/Expiratory upstroke/ Early exhalation phase: CO2 from alveoli reaches the upper airway and causes a rapid rise in the amount of CO2 that is detected on the monitor.

Phase III aka Expiratory plateau phase: CO2 rich air is exhaled out

ETCO2 i.e. end of exhalation contains the highest concentration of CO2 (normal value is about 35-45 mmHg).

Phase IV aka Descending/ Expiratory downstroke: Inspiration begins and CO2 in the airways drops down to zero.

Normal capnograph wave

Note: The baseline represents the inspiratory phase (not expiratory)

Normal capnograph

Increase in ETCO2 (See the waveform below)

Hypoventilation

Increased muscular activity

Malignant hyperthermia

Increased Cardiac Output or Bicarbonate infusion

Relief from bronchospasm

Increasing ETCO2 (Ex. Hypoventilation during procedural sedation)

Decrease in ETCO2 (See the waveform below)

Hyperventilation

Muscle relaxants and hypothermia

Decrease cardiac output

Pulmonary embolism 

Bronchospasm

Decreasing ETCO2

Clinical Applications:

1. Airway management: To confirm the ET tube placement, also for continuous confirmation of the airway
2. Monitoring CPR efficacy: Target ETCO2 >20 during CPR
3. Estimates prognosis during CPR: An end-tidal CO2 value < 10 mm Hg after 20 min of resuscitation has been shown to be very accurate in predicting death
4. Confirming ROSC without stopping chest compressions: With ROSC ETCO2 shows as a sudden increase
5. Monitoring PaCo2 in a Traumatic Brain Injury/ Post Cardiac Arrest care
6. Guide to ventilation during procedural sedation: Shows hypoventilation i.e increasing ETCO2 at least 60 seconds prior to hypoxia 
7. Fluid responsiveness (5% or greater increase in ETCO2 following a passive leg raise is a non invasive way of predicting fluid responsiveness)
8. Diagnosing other pathologies (PE, DKA)

ETCO2 waveform in other pathologies:

Airway obstruction pattern (Bronchospasm)

Rebreathing

Esophageal intubation

On Muscle relaxants

Take Home

• ETCO2 is a surrogate marker for arterial CO2. If increased, it confirms hypercapnia.
• ETCO2 changes immediately with changes in the amount of CO2 in the airway (unlike SpO2 that shows a lag)
• When using waveform capnography, look at the ETCO2 numeric value as well as the waveform.
• Eliminate pulse checks during CPR, use ETCO2 instead.

References:

1. Heradstveit BE, Heltne JK. PQRST - A unique aide-memoire for capnography interpretation during cardiac arrest. Resuscitation 2014; 85:1619-20.
2. Monnet, X. et al. ETCO2 is better than arterial pressure for predicting volume responsiveness by PLRT. Intensive Care Med. 2013 Jan;39 (1): 93-100
3. http://www.medscape.com/viewarticle/812011
4. http://edtech2.boisestate.edu/meganjacobson/502/capno.html
5. http://www.carefusion.com/pdf/Center_for_Safety/Documents/RC1706-L3017-Capnography-Handbook.final.pdf

Running the code

This week, lets go through some key points on cardiac arrest. Some of these form the fundamentals of CPR in addition to other important points which are not talked about when we do the routine life support courses.

1. High quality CPR
Well, we all know this, Right?

• Rate:100-120/min
• Depth: 5cm approximately
• Allowing full chest recoil
• Not to hyperventilate
• Minimising interruptions

This is something that is really stressed on during the life support courses. Well, this is because survival is linked to the quality of CPR and there should not be any excuses here. This is very basic simple stuff that can make a difference. So how are doing it so far?

Current literature says we are slow/ shallow with chest compressions and do not allow adequate recoil. So next time when you run a code, make sure that you stick to these points and especially stay away from interruptions.

Reasons for interruptions: 

a) Airway: Securing the airway should be individualised for every patient. There is no magic number here. For a witnessed arrest with presumed cardiac cause, airway can be delayed for 8-10 minutes whereas early airway control should be done for a hypoxic arrest (drowning, pulmonary edema). In India, pre-hospital intubations are rare and by the time patients are brought to a hospital, airway should be secured ASAP on arrival with minimal interruptions to chest compressions. This is not the time for a novice to try intubation, it should be done by the most experienced provider around. 

b) Pulse Checks: Checking pulse during CPR is unreliable and should not be done, instead use ETCO2 to look for the ROSC. DO NOT STOP COMPRESSIONS TO CHECK FOR PULSE. 

c) Peri shock pauses: Shock can be delivered with transcutaneous pads or paddles and in India, the use of paddles is far more common than pads. 
With every 5 seconds of peri shock pause, there is an 18% decrease in survival. It is recommended to continue to deliver compressions while charging the defibrillator and once it is charged, only then hold the chest compressions for probably < 5 seconds, deliver the shock and resume compressions. It is painful to see those providers, who stop compressions as soon as they touch the paddles, then charge the defibrillator and then deliver the shock. This way it roughly takes about 20-30 seconds.

If there is expertise available, use intra arrest ECHO to pick up a tamponade or dilated RV, but again minimise compressions (Transesophageal ECHO is coming to the ED's soon..)


2. Hemodynamics Guided Resuscitation
Choose one of these three to judge your performance and hemodynamic status:

a) Coronary Perfusion Pressure (needs an arterial line and central line to monitor CPP)

• Our goal is to achieve an adequate Coronary Perfusion Pressure (CPP) i.e. CPP > 20mm Hg
• CPP = Aortic DBP - Right Atrial Pressure (RAP) 

OR

b) Diastolic Blood Pressure (needs just an arterial line)

• Insert a intra arrest femoral arterial line and target DBP > 40mm Hg 
• If < 40, improve CPR or give epinephrine
• If > 40, no need to give epinephrine, continue high quality CPR

OR

c) ETCO2 

• When you can't get an arterial line, use waveform capnography
• It is the continuous non invasive measurement end tidal CO2 using a sensor, the value is displayed on the monitor as a number.
• ETCO2 acts as a surrogate marker of cardiac output in addition to confirming the ET tube placement and ROSC.
• Target ETCO2 > 20mmHg 

3. Medications
Theoretical benefit: Improve CPP, CPP
Detrimental effects: Increase myocardial O2 demand, post ROSC myocardial dysfunction

Epinephrine (Adrenaline)

• No difference in outcomes, but we are finding it hard to stop using it!!
• Literature says more epi = no change or worse outcomes.
• With epi you are more likely to achieve ROSC, but worsen the neurological outcomes.
• Read more on epinephrine here by Dr. Anand Swaminathan (@EMSwami)

Give q5min epi now if you have been doing q3min so far and watch out for the next ACLS update OR use Hemodynamics Guided Resuscitation. 


3. Team Leadership

• This is by far the most important take home point from this post. Your leadership skills, ability to mobilise resources and getting things done can affect the outcome of a code. With experience we need to learn how to take control of the situation and communicate effectively under stress. Just knowing the algorithms is not enough.
• Good Leadership: Appropriate role assignment, better communication, reduces errors and establishes ROSC faster
• Errors are made due to indecisive and weak leadership which can cost a life.
• If there is time available, brief your team prior to the code and always debrief after you are done with the code regardless of the outcome. This will improve the team dynamics for future resuscitations. 
• 

So take the charge, assign tasks, be decisive, communicate early, clearly and effectively.

Take Home:

• Don't forget the basics, focus on high quality CPR
• Don't flood them with epinephrine instead use Hemodynamics guided resuscitation (CPP, DBP or ETCO2)
• Communicate early, clearly and effectively. Good leadership saves lives..

Thank You

References:

1. Michael Winters, MD: Running the Perfect Code in 2015 (AAEM Scientific Assembly) 
2. Castelao, Ezequiel Fernandez, et al. "Effects of team coordination during cardiopulmonary resuscitation: A systematic review of the literature." Journal of critical care 28.4 (2013): 504-521.CPR quality- Consensus 
3. Panesar, Sukhmeet S., Agnieszka M. Ignatowicz, and Liam J. Donaldson. "Errors in the management of cardiac arrests: An observational study of patient safety incidents in England." Resuscitation 85.12 (2014): 1759-1763.
4. Cheskes, Sheldon, et al. "Perishock Pause An Independent Predictor of Survival From Out-of-Hospital Shockable Cardiac Arrest." Circulation 124.1 (2011): 58-66.
5. Sunde, Kjetil, and Theresa M. Olasveengen. "Towards cardiopulmonary resuscitation without vasoactive drugs." Current opinion in critical care 20.3 (2014): 234-241.
6. Stiell, Ian G., et al. "Advanced cardiac life support in out-of-hospital cardiac arrest." New England Journal of Medicine 351.7 (2004): 647-656.Johnson NJ et al Resuscitation 2014
7. Sutton, Robert M., et al. "Hemodynamic-directed cardiopulmonary resuscitation during in-hospital cardiac arrest." Resuscitation 85.8 (2014): 983-986.