So does it work or not?

Just got my First Responder/CPR/AED/O2 certification. OK, yea me.

Spoke with a very good friend who, as part of a full-time tac team, received quite a bit of advanced emergency trauma training. We talked about the stuff I'd learned in class and his opinion was that most of it was wishful thinking. He doesn't claim to be an expert by any means, but it raised a lot of questions that I thought the experts here might be able to explain.

Examples:

Tourniquets: Official DOT/ARC word-of-God is that you never put a tourniquet on unless you've decided, in effect, to amputate the limb. Official procedure is bandage, if bleeding continues more bandage, if bleeding continues pressure point, if bleeding continues then tourniquet if and only if medical help is > 30 minutes out.

I'm not a doctor, but I have a hard time believing someone with a sliced open femoral artery is going to last 30 minutes. When I raised this point in class, the instructor basically said, "this is what DOT/ARC teaches ... use your judgment."

My friend's take: if you know you have a serious arterial bleed, it's time for the tourniquet. By the time you've gone through all the other steps, the victim might not have enough blood left to be worth worrying about. Also, contrary to the DOT/ARC view -- "once you put a tourniquet on you've poisoned the limb and it's probably going to be lost" -- apparently there is quite a bit of evidence that limbs have survived hours after a tourniquet.

So which is it?

Open chest wound: We were taught occlusive dressing, taped down on three sides, and "burp" the air/blood from a pneumothorax or hemothorax.

Friend's take: you need to get something inserted into the chest to drain the pressure actively. This is obviously well beyond the scope of what we were taught in EFR.

CPR: Based on what my friend relayed and what I read here in the "when your patient dies" thread, it sounds like CPR has an almost 0% success rate. WTFO? Is that a matter of timing -- professional rescuers arrive too late for it to matter, but someone on the scene at the moment of arrest might be able to make a difference -- or is it really just a feel-good thing that people learn to say they've learned it?

[Gutshot John]

I know it's not going to be the answer you want to hear, but ultimately they are both correct. The question is WHICH is your standard of training.

You completed a curriculum that only gradually increases in aggressiveness towards hemorrhage control. It subscribes to an ANTIQUATED doctrine that still exists that tourniquets destroy a limb by cutting off all blood flow.

More recent studies discredit this information and has shown little long-term adverse affects either nerve or vascular due to tourniquet application even for hours. This however is new. The old "bad" information hasn't been fully processed out of the curriculum.

The issue for you as first responder is whether you can apply that information without some risk. If you deviate from the standards of our training, you open yourself up to significant liability. This may not be a problem if it's YOU that's got the hemorrhage, but if you have to treat someone who might end up suing you, they might make an argument that you deviated from your standards and therefore not covered by good samaritan protections. My suggestion is to be very quickly moving through the different levels (you can probably ignore the pressure point method) until you get to the tourniquet. You talked about 30 minutes of trying to stop bleeding, that's not realistic to my way of thinking...you should have moved through the steps within 2 minutes. You also have to consider that you're probably going to have to move/transport someone.

If you go through those steps, albeit quickly/perfunctorily, you limit your liability as its still consistent with your training standard. You're a lawyer and you know how it works.

CPR has almost 0% success, I've never seen it work but I almost always got there several minutes after the person went down. If applied rapidly (within seconds) it might have greater effect. Mostly paramedics do CPR to show the family that we're trying to save the person pumping blood until we can get to a hospital where the Doc can call it. If you're having to apply CPR to a guy for massive hemorrhage he's pretty much dead.

PS. I don't care what class you take, you're not going to be doing a chest tube. No First Responder is going to have the wherewithal to put in a tube. Your buddy has an exceptional amount of training, but I'd be skeptical that he gets to apply it that often.

Originally Posted by ToddG

Just got my First Responder/CPR/AED/O2 certification. OK, yea me.

Spoke with a very good friend who, as part of a full-time tac team, received quite a bit of advanced emergency trauma training. We talked about the stuff I'd learned in class and his opinion was that most of it was wishful thinking. He doesn't claim to be an expert by any means, but it raised a lot of questions that I thought the experts here might be able to explain.

Examples:

Tourniquets: Official DOT/ARC word-of-God is that you never put a tourniquet on unless you've decided, in effect, to amputate the limb. Official procedure is bandage, if bleeding continues more bandage, if bleeding continues pressure point, if bleeding continues then tourniquet if and only if medical help is > 30 minutes out.

I'm not a doctor, but I have a hard time believing someone with a sliced open femoral artery is going to last 30 minutes. When I raised this point in class, the instructor basically said, "this is what DOT/ARC teaches ... use your judgment."

My friend's take: if you know you have a serious arterial bleed, it's time for the tourniquet. By the time you've gone through all the other steps, the victim might not have enough blood left to be worth worrying about. Also, contrary to the DOT/ARC view -- "once you put a tourniquet on you've poisoned the limb and it's probably going to be lost" -- apparently there is quite a bit of evidence that limbs have survived hours after a tourniquet.

So which is it?

Open chest wound: We were taught occlusive dressing, taped down on three sides, and "burp" the air/blood from a pneumothorax or hemothorax.

Friend's take: you need to get something inserted into the chest to drain the pressure actively. This is obviously well beyond the scope of what we were taught in EFR.

CPR: Based on what my friend relayed and what I read here in the "when your patient dies" thread, it sounds like CPR has an almost 0% success rate. WTFO? Is that a matter of timing -- professional rescuers arrive too late for it to matter, but someone on the scene at the moment of arrest might be able to make a difference -- or is it really just a feel-good thing that people learn to say they've learned it?

[JamesL]

Tqs:
In short, properly used and designed, Tqs save limbs with very small risk of limb damage. Of course, direct pressure should be used before hand, but National Registry recently removed limb elevation and pressure points from their hemorrhage control skill sheet - so its now direct pressure then tqs if hemorrhage control fails. Check with your local protocols, so agencies (like mine) still feel like tqs are a no go.

Open Chest wound:
Your friend is right in that needle decompression then chest tubes will relive a tension pnemuo, but burping the wound might do the job as well. Do the best you can within your scope.

CPR:
Traumatic arrest has very low to no chance in getting a patient back. However, for most civilians, non traumatic cardiac arrests have the best possible chances with high quality CPR (minimize hands off time, let the chest fully recoil), rapid AED use and rapid transport. CPR alone has a very low (if at all) chance of getting someone back.

[Skintop911]

Originally Posted by ToddG

Tourniquets: Official DOT/ARC word-of-God is that you never put a tourniquet on unless you've decided, in effect, to amputate the limb. Official procedure is bandage, if bleeding continues more bandage, if bleeding continues pressure point, if bleeding continues then tourniquet if and only if medical help is > 30 minutes out. I'm not a doctor, but I have a hard time believing someone with a sliced open femoral artery is going to last 30 minutes. When I raised this point in class, the instructor basically said, "this is what DOT/ARC teaches ... use your judgment." My friend's take: if you know you have a serious arterial bleed, it's time for the tourniquet. By the time you've gone through all the other steps, the victim might not have enough blood left to be worth worrying about. Also, contrary to the DOT/ARC view -- "once you put a tourniquet on you've poisoned the limb and it's probably going to be lost" -- apparently there is quite a bit of evidence that limbs have survived hours after a tourniquet. So which is it?

That's the current curriculum for AHA, ARC, DOT, and several other first aid programs. Current PHTLS curriculum is teaching direct pressure (manual or mechanical), followed by a tourniquet is DP isn't effective. The new proposed (and approved, IIRC) DOT curriculums follow that. Research showed that pressure points and elevation didn't have much effect on patient outcomes, and tourniquets didn't have the negative effects once thought.

There have been folks that knew better and taught alternatives all along, but the data from Iraq/Afghanistan is now change in the mainstream. War is useful in that way.

Good stuff with burn treatment as well, but not for pre-hospital.

Open chest wound: We were taught occlusive dressing, taped down on three sides, and "burp" the air/blood from a pneumothorax or hemothorax.

Friend's take: you need to get something inserted into the chest to drain the pressure actively. This is obviously well beyond the scope of what we were taught in EFR.

Relieving a ptx is easy, and is now commonly taught to deploying soldiers and other groups. Curriculums for lay rescuers (ARC, AHA) still turn their noses up at it.

Chest tube is quirkier.

CPR: Based on what my friend relayed and what I read here in the "when your patient dies" thread, it sounds like CPR has an almost 0% success rate. WTFO? Is that a matter of timing -- professional rescuers arrive too late for it to matter, but someone on the scene at the moment of arrest might be able to make a difference -- or is it really just a feel-good thing that people learn to say they've learned it?

I've done CPR umpteen times, and only brought back folks to die at the hospital.

Best stats are with witnessed SCA in otherwise healthy folks. All others have consistently poor outcomes. In the case of cardiac arrest as a result of trauma, most systems won't resuscitate.

Add in things like ~10% survivability loss with each passing minute, response time realities in most systems, and the picture is pretty darn bleak.

Do what you can, save those you can, but some folks will die.

[txfireguy2003]

Listen to what these guys are saying. The fact is, less than 1% of cardiac arrests survive, but high quality CPR and electrical therapy have been the only two therapies shown to have even a slight improvement on patient survival. As far as trauma goes, the only thing that's going to save the guy is surgery, plain and simple, so your goal should be aimed at getting the patient to a surgical center alive. As was said, the NREMT has moved away from the old pressure, elevate, pressure point, then tourniquet method of bleeding control and moved to tourniguets as the second line treatment for bleeding control. This comes from the fact that tourniquets are used routinely in surgical situations with little to no damaging effects. Studies of trauma patients have shown a significantly higher survival rate with patients treated and transported by basic level responders over advanced level responders (ie Paramedics) because the basic guys just load the patient and run, while the Medics want to hang around and play with IV's and what not, when in reality, they should be doing that stuff enroute to the hospital. So do what you're trained to do, very quickly and get on the road. And don't think that your CPR will have no effect, in reality, it probably has more effect on the patient than all the drugs and IV's in the world. The only thing an advanced level responder can do that has a proven effect is intubation, and even that only has an effect on outcome if the patient's airway is compromised to the point where BVM and basic airway adjuncts are useless.

[meisterhau]

Originally Posted by Gutshot John

PS. I don't care what class you take, you're not going to be doing a chest tube. No First Responder is going to have the wherewithal to put in a tube. Your buddy has an exceptional amount of training, but I'd be skeptical that he gets to apply it that often.

I've done one. Extremely f'd up situation. I hope like hell I *NEVER* am in a situation like that ever, ever again. The suck-meter was pegged. This was a decade + ago, as a street paramedic.

I took a very bad patient (bad off, not bad person) into the trauma center. He'd been stabbed (by someone who wanted his shoes, for God's sake... his shoes...) in the flank. Tension hemothorax. Evac via air was unavailable, so we scooped him up and hauled ass. Two large-bores, a chest seal, and some of the craziest stuff I've ever seen on a monitor. Decent consult, and trauma was definitely ready for us when we rushed through the door... and I was at the head of the stretcher. The surgical trauma team is some kind of amazing... everything happens like RIGHT THE F NOW in a team like that. I knew the doc from clinicals and from multiple past patients - good rapport. He looked at me, basically said "you doing this or me?" and talked me through it.

Again... NEVER AGAIN do I want to be there. I was shaking for an hour afterward.



Protocols, jurisdiction, and level of care/training do play in to this very, very heavily. Had I attempted something like that in the street without being supervised, I'd have at least lost my certs, if not much worse. The furthest we were instructed at that time was to use a large-bore catheter to decompress the lung, and that would have required consult or paperwork for weeks to justify.

After this, I went on to do some remote location stuff that required additional training. Even there, where we were taught to do surgical crichothyrotomy, we still were not taught to do a surgical chest tube.

None of my training was military.

This was MY experience. Others may have significantly different ones. Things may also have progressed as time moved forward, too. I'm not on the street or in the business anymore... everything lapsed about 3 years ago. Someone else's watch now...

[Gutshot John]

Originally Posted by meisterhau

I've done one. Extremely f'd up situation. I hope like hell I *NEVER* am in a situation like that ever, ever again. The suck-meter was pegged. This was a decade + ago, as a street paramedic.

I took a very bad patient (bad off, not bad person) into the trauma center. He'd been stabbed (by someone who wanted his shoes, for God's sake... his shoes...) in the flank. Tension hemothorax. Evac via air was unavailable, so we scooped him up and hauled ass. Two large-bores, a chest seal, and some of the craziest stuff I've ever seen on a monitor. Decent consult, and trauma was definitely ready for us when we rushed through the door... and I was at the head of the stretcher. The surgical trauma team is some kind of amazing... everything happens like RIGHT THE F NOW in a team like that. I knew the doc from clinicals and from multiple past patients - good rapport. He looked at me, basically said "you doing this or me?" and talked me through it.

Again... NEVER AGAIN do I want to be there. I was shaking for an hour afterward.



Protocols, jurisdiction, and level of care/training do play in to this very, very heavily. Had I attempted something like that in the street without being supervised, I'd have at least lost my certs, if not much worse. The furthest we were instructed at that time was to use a large-bore catheter to decompress the lung, and that would have required consult or paperwork for weeks to justify.

After this, I went on to do some remote location stuff that required additional training. Even there, where we were taught to do surgical crichothyrotomy, we still were not taught to do a surgical chest tube.

None of my training was military.

This was MY experience. Others may have significantly different ones. Things may also have progressed as time moved forward, too. I'm not on the street or in the business anymore... everything lapsed about 3 years ago. Someone else's watch now...

Exactly, on average it's a once in a lifetime event for most medics, and should be even rarer for first responders. The only time I had significant chest tube protocols was when I worked in Wilderness EMS and transport times averaged 3+ hours. The only time I had to do one was in the military in the same sort of capacity. Doc talked me through it on the radio and pretty intense/imperfect conditions. Guy was in agony.

Todd, see if you can take a PHTLS or ITLS class or whether you need to be an EMT, this should have more modern training relative to tourniquet application. You can be sure however that the old information is being rapidly phased out.

Thanks for the feedback so far, gentleman. It's genuinely appreciated.

PHTLS = ?
ITLS = ?

Two things I need to clear up:

1. I don't think our instructor was ignorant of what you're saying, she was just very clearly being held to the ARC training protocol.

2. Didn't mean to imply that my buddy considered himself a combat medic. Far from it. When he mentioned needle decompression, e.g., it was in terms of "someone is going to have to do that" not "this is what I'd do!"

[NinjaMedic]

CPR does work, our survival to hospital discharge rate is in the low 20's last I checked. Not great but definitely not not 0%, and our ROSC (return of spontaneous circulation)(AKA getting pulses back) rate is almost 50% now i believe.

You will never convince me that the typical civilian not on an ambulance will ever generally need to decompress a tension pneumo, it is rare enough even on a high-volume urban/suburban/rural ambulance.

PHTLS = Pre Hospital Trauma Life Support
ITLS = International Trauma Life Support (formerly known as BTLS which is basic trauma life support.

ETA - I believe those figures are for pt's whose initial rhythm is something other than asystole.

[Barbara]

Todd, see if you can take a PHTLS or ITLS class or whether you need to be an EMT, this should have more modern training relative to tourniquet application.

Unfortunately, not. Tourinquet as last resort only was standard in the Basic class I just finished.

[meisterhau]

Originally Posted by ToddG

Thanks for the feedback so far, gentleman. It's genuinely appreciated.

Not sure if anyone actually said it, but... good on you, Todd, for seeking some fundamental first aid training. Even things like the AED in the food court at the mall now mean something. Hopefully, you'll never need this stuff, but in truth, you probably will. Wish more people were willing to man up. I think it's awesome that you're thinking this through, and putting real-world application to it.

Originally Posted by ToddG

1. I don't think our instructor was ignorant of what you're saying, she was just very clearly being held to the ARC training protocol.

... as she had to. She'd be negligent to teach you things that are outside of the scope/protocols. The First Responder level is precisely what it is - fundamental ABCs - not med-surgical stuff. That's no slight on the cert - every paramedic worth a damn knows that a good FR or EMT-B is a HUGE asset. It's not high-level, though, so only the basics are taught. Some of it, as we've been discussing, is lagging behind the change curve.

I don't know if PHTLS or ITLS require you to be an EMT-B (or higher), or if a first responder can take the class, but it is a good thought. (EMT-B is also a great course - if keeping that level of cert up here wasn't a giant ass-ache, I'd go back just 'cause...) There is a ton of "alphabet soup" here in the medical world as there is anywhere... Things like ACLS and PALS aren't going to be useful to you (both advanced life support stuff with all the cardiac meds and whatnot). I was going to strongly suggest BTLS (basic trauma life support), but then realized that it had evolved into ITLS. That class was a challenge - had some tough instructors - but it was very, very cool.

Originally Posted by ToddG

2. Didn't mean to imply that my buddy considered himself a combat medic. Far from it. When he mentioned needle decompression, e.g., it was in terms of "someone is going to have to do that" not "this is what I'd do!"

Regardless, it's not something YOU should do, unless you advance your training and are operating under those protocols, or have no recourse but an exception. It is, however, great to be familiar with what SOMEONE can do, and who that someone is and can be summoned if needed. You obviously know this already...

[Joe_Friday]

I will have to agree with TacMedic4450 and disagree with most on here on the CPR issue. I have a few Life Save ribbons and certificates to prove that CPR does work and that patients can walk out of the hospital and continue thier lives. My father-in-law is a prime example. He is retired out of the Army and has been so for around 15 years, he is very overwieght, and does not follow any type of fitness routine. While in FL for work he went into cardiac arrest in the parking lot of a restraunt and his coworkers performed CPR. Poorly I might add, as one of them even stated that he did a Precordial Thump because he saw it done on TV and they inserted a pocket knife in his mouth to open the airway. The Med Unit arrived 8 minutes later and attempted intubatiuon and IV therapy and were unsuccesful on both counts. They continued with much better CPR and O2 and transported. He walked out 9 days later. So, immediate CPR + no O2 + no Meds + total time from collapse to EC being over 20 minutes = Save. I know it's not typical but it does happen.

Another case. I ran back up to another unit where the patient went into CA in a gym. Two people began CPR immediately (Trauma Surgeon and Cardiologist, what luck huh!) and the first unit shocked on scene. We arrived and a second shock was delivered. When I went to establish an IV access point the patient tried to sit up on the stretcher and said "what the hell are you doin'!". Before leaving the scene he had told us all the info we needed and how to contact his wife. He is still alive today (happened about 5 years ago) and he is doing well. I talked with him two weeks later and he actually told me everything that had happened form the instant that he collapsed until he "woke up". Sounds crazy but I was the only person that he had talked to that had been there and when I asked the first in medics about what he said, they agreed with all of it. I now take a different approach to what I say in front of all patients, living or deceased.

Originally Posted by meisterhau

Not sure if anyone actually said it, but... good on you, Todd, for seeking some fundamental first aid training.

Thanks. The truth is, for years I've said that any responsible firearms instructor should have some fundamental training in dealing with GSWs and range-related injuries ... and then I immediately had to follow it up with "but I don't, and I suck." My major motivation was definitely the students in my classes.

Regardless, it's not something YOU should do, unless you advance your training and are operating under those protocols, or have no recourse but an exception.

Dude, the only way I'm sticking something sharp & pointy into someone's chest is if he's trying to kill me.

[HowardCohodas]

My class was made up of all LEOs and one civilian, me. Therefore, in addition to the basic requirements to pass the test, much of the instruction was centered around the types of things they would encounter and the equipment they carry in their duty vehicles. Our instructor was active so she related real life stories to illustrate the points. She was clear about what answers were required to pass the test, but pointed out alternatives that her team had used. Even my cousin, the physician says your questions are unresolved in the medical community.

My conclusion... Just like a SD incident, rely on your training, use your best judgment, save a life if you can, contact a lawyer to sort out the rest.

[FMF_Doc]

Todd- the traditional wisdom has always been that TK is the last resort, more recently the military has changed its mind on the immediate use of TKs and that the transport times reduce the likelihood of losing a limb due to using one. You can fix most everything but dead from bleeding out isn't one of them.

CPR- my personal and professional opinions of CPR are that it provides at least a 30% chance of survival if performed correctly and in a timely manner, keeping the blood moving and oxygenating the tissues until advanced life support arrives is better than having absolutely 0% chance at all. Yes most likely if you are doing CPR you are doing it to make the family, coworkers, bystanders and yourself feel better knowing that you did something.

I have had 6 saves (out of 100's of cases) in 20 years of providing advanced prehospital and clinical care, but I would not hesitate to do CPR even given the odds and experiences.

You do what you are trained to do and if everything works out it's a good day, if not you drive on and try to save the next one.

It gets frustrating and depressing but you still do your best.

[VTLO910]

Note on CPR:

Supposedly the newer CPR that focuses on compressions almost exclusively to deliver the needed oxygen to the body is getting higher survival rates...

I just stopped working EMS FT a lil over a year ago, so I have not done my pushies ans puffies since... But I can understand the concept.


This is also good since most folks are afraid of getting their mouth near another persons. I think this newer style may actually make bystanders more willing to get a bit dirty and help.

Just don't tell them that the majority will have broken ribs and /or have vomited from the compressions...lol

[Skintop911]

Originally Posted by Joe_Friday

I will have to agree with TacMedic4450 and disagree with most on here on the CPR issue. I have a few Life Save ribbons and certificates to prove that CPR does work and that patients can walk out of the hospital and continue thier lives.

The key word is "can." No one is saying otherwise. CPR can and does work, just not anywhere near as much as people think. We'd all agree that it's better than nothing, too.

Originally Posted by VTLO910

Note on CPR: Supposedly the newer CPR that focuses on compressions almost exclusively to deliver the needed oxygen to the body is getting higher survival rates...

That's what they're saying. We'll see. The science, models, and collateral stats are supportive, though.

"Pushies and Puffies." Haven't heard that one.

[Gutshot John]

There needs to be a distinction between MI survival rates, and the effectiveness of CPR.

I've never seen CPR (BASIC life support) resuscitate someone by itself though it definitely beats doing nothing.

Applying ALS techniques and definitive hospital care and survivability does indeed shoot up significantly though most people still die.

30% success rate for CPR is wildly optimistic.

[brit]

The success rate for CPR is 8%, it has been the same 8% for the last 20 years.

This information came from two paramedics that instructed both my CPR class and ECA classes

[Pathfinder Ops]

Get hold of the TCCC info and you will have the answers short and straight to your questions.

The tourniquet studies alone negate any of the historic..."apply a tourniquet, lose a limb" discussion. The studies behind TCCC clearly indicate that touniquets are APPROPRIATE immediate intervention even where there is NO ARTERIAL bleeding.

According to studies from the Vietnam conflict alone, there is an estimated 2500 Soldiers/ Marines who bled to death from wounds NOT involving an artery. Simple bleeding control and the ability to recognize and then address a pneumothorax or sucking chest wound would have resolved the life threat in those lives.

Studies since then and especially secondary to the Battle of Mogadishu and the first Gulf war through current "lessons learned" show that the immediate placement of a tourniquet in what is termed the "Care Under Fire" phase is not only prudent but it is definitive care.

My company teaches the Combat Lifesaver Course to guard units deploying to the current theaters and the TCCC curriculum is very clear about this topic.

Traumatic cardiac arrest has less than 1% response to CPR, making it a no go in the tactical setting and and not a real consideration in the conventional EMS system.

There is a difference between a "sucking chest wound" and a pneumothorax. Each has its own treatment. In a sucking chest wound there is a hole that should be addressed in the way you describe with a 3 sided occlusive dressing or a "Asherman" type chest seal.

With the closed chest injury where a pneumothorax is present you will need to vent the chest.

Here are some of the statistics straight from the Military TCCC curriculum:

About 90 percent of combat deaths occur on the battlefield before the casualties reach a medical treatment facility (MTF).
Most of these deaths cannot be prevented by you or a surgeon.
Examples: Massive head injury, massive trauma to the body.

These are stats from Mogadishu through today:

KIA: 31% Penetrating head trauma
KIA: 25% Surgically uncorrectable torso trauma
KIA: 10% Potentially surgically correctable trauma
KIA: 9% Hemorrhage from extremity wounds
KIA: 7% Mutilating blast trauma
KIA: 5% Tension pneumothorax
KIA: 1% Airway problems
DOW: 12% Mostly from infections and complications of shock

An interesting side note here is that the statistic of 12% that die from Infections and symptoms of shock is the same percentage that die for that reason since the Crimean War. Yeah no change in that number.

Also note that only 1% of deaths were "airway" problems making them almost an after thought. and in fact we teach it as a secondary consideration to bleeding control. This is something our Tactical Medic students struggle to wrap their heads around at first. For conventional EMS personnel its a new way of doing an assessment.

About 15 percent of the casualties that die before reaching a medical treatment facility can be saved if proper measures are taken.
Stop severe bleeding (hemorrhaging)
Relieve tension pneumothorax
Prevent worsening breathing status
Restore the airway
Instead of ABCs……think CABCs

The above notes are taken right from our TCCC lecture.