Pre-operative lab value tutorial

An important part of the preoperative evaluation is knowing when it is appropriate to order certain labs and how to evaluate their values. This can be, at times, very tricky even for anesthesia providers that have been practicing for some time. As a brand new student, seeing and evaluating all of these numbers can be very overwhelming. This tutorial is meant to help make evaluating labs a less daunting task. If nothing else, you should leave this page with the ability to recognize when lab values are outside of their normal range. Being able to know what to do, if anything at all, is another story and will eventually come with time. This is a starting point. If you see lab values that are out of the norm, use it as an opportunity to question why this is the case. Start a discussion with your instructor any chance you get, and it will start to make sense sooner.

Obviously we can’t order every available lab value for every single patient. For some people and surgeries, it would just be a waste. As with many things in anesthesia, it is important to weigh out the risk and cost versus the benefits when deciding what labs to order. Often times, you will not be the person ordering the labs, but it is something important to start thinking about; especially when it comes to acknowledging when an important value has not yet been determined for a patient. Ultimately lab values can aid you in confirming or excluding the presence of a disease, reduce risk, limit patient morbidity and mortality during surgery, and reduce costs. In addition to this, they can also be costly and time consuming to evaluate. You will have to use your best judgment to determine when you think they are needed.

BMP – Basic metabolic panel (AKA Chem-7)

Can potentially clue you in to information about fluid and electrolyte balances, kidney function, blood-glucose levels, and responses to various medications.

When might it be a good idea to order?

• Underlying disease: HTN, Obesity, Heart failure, Kidney disease, liver disease, diabetes, CNS disease, endocrine disorders.
• Using certain meds: diuretics, ACE inhibitors & ARBs, NSAIDs, Steroids, Digoxin, Aminoglycosides.

Normal ranges of values:

• Na – 135-145 mEq/L
• K – 3.5-5.1 mEq/L
• Cl – 95-109 mEq
• HCO3 – 22-26mmol/L
• BUN -7-22mg/dL
• Cr – 0.5-1.4 mg/dL
• Glucose(fasting) – 70-100mg/dL

A few values to focus on:

• Cr: Creatinine – Creatinine is a breakdown product of creatine phosphate in muscle, and is usually produced at a fairly constant rate by the body. Men generally have more muscle, so their levels will be elevated. It is excreted unchanged by the kidneys, so provides a good evaluation of kidney function. It is inversely related to GFR. In geriatric patients, muscle mass decreases while kidney function is decreased, leaded to Cr levels remaining relatively unchanged in patients with relatively good kidney function.  

• BUN – Blood Urea Nitrogen – Produced in the liver. It is directly related to protein catabolism and inversely related to GFR. Not always a reliable indicator of GFR, because protein catabolism may be impaired.

• Bun:Cr ratio: Normally = 10:1.      >15:1 can be a sign of volume depletion in patients.  

• K – Potassium – Generally speaking, elevated potassium levels are more of a concern than low levels. Low levels will rarely cause any issued or give reason for delayed surgery, unless they reach critical levels close to 2.0. In this case, they can be a cause for rhabdomyolysis. May be low in patients taking diuretics. Elevated levels on the other hand are more a cause for concern. You will often see elevated levels in end stage renal disease patients, patients taking potassium sparking diuretics, and patients taking ACE inhibitors or ARBS. Large increase can cause progressive EKG changes and eventually lead to cardiac arrest if not properly treated. Drugs such as succinylcholine can lead to increased levels of K, so be careful when using.

• Glucose – Maintaining blood glucose close to the patient’s baseline can play an important role in preventing surgical site infection. Low glucose levels can make patients lethargic and lead to delayed emergence from anesthesia.

Coagulation Studies

Determine the clotting tendency of blood.

When might it be appropriate to order?

• Known coagulation disorders, age >75, kidney or liver disease, diabetic, major procedure with lots of anticipated blood loss, planned epidural/spinal placement, taking anticoagulant therapy, pregnancy, trauma, sepsis.

Normal range of values:

• PT – 10-12 secs
• PTT – 25-35 secs
• INR – 0.8-1.2 secs

What these values can tell you:

• PT – Prothrombin time – Prolonged when there are issues with the extrinsic clotting pathway. Often see elevated times in patients with vitamin K deficiency, liver disease, and on warfarin therapy.

• PTT – Activiated Partial Thromboplasin Time –Prolonged when a patient has issues with the intrinsic pathway. Often see elevated times in patients receiving Heparin, hemophiliacs, and Von Willebrand’s pateints.

• INR – International Normalized ratio – Basically the same as PT. It is a standardized PT, designed to account for differenced in thromboplastin. Target for patients on Warfarin is generally 2.0-3.0.

CBC – Complete Blood Count

Provides information about the cells inside the patient’s blood.

When might it be a good idea to order?

• Age >75, major procedure with lots of anticipated blood loss, chronic kidney or liver disease, anticoagulant use, bleeding disorders, clinical signs of anemia, trauma, infection, pregnancy.

Normal range of values:

• WBC – 4.0-10.5
• Hemoglobin – Men: 14-18g/dL; Women: 12-16g/dL
• Hematocrit – Men: 40.7 – 50.3%; Women: 36.1 – 44.3%
• Platelets- 150 – 440
• What these values can tell you:
• WBC – Elevated levels can be a sign of infection or sepsis.

What these values can tell you:

• Hemoglobin – Low values can tell you when a patient is anemic. In these situations, they may have recently been bleeding, are currently bleeding, or may have impaired kidney function. Elevated levels usually mean the patient is dry and may need fluid resuscitation with IV crystalloids.  

• Hematocrit = about 3xHbg. Basically clues you in to the same things as listed above.

• Platelets – The most important value in evaluating primary hemostasis. Below 150 is considered thrombocytopenia. Lower values are associated with increased intraoperative bleeding.

I hope this provides a good starting point and reference. Don’t be afraid to come back and review this material over time. It will continue to be useful throughout your time as a student and a practitioner. 

Commonly Used OR Antibiotics

Giving IV antibiotics prior to surgery is one of the more important actions we can take as anesthesia providers to prevent surgical site infection. Early on in your education it may seem like every patient gets 2 grams of Ancef, but this is certainly not always the case. This tutorial is designed to help you understand and know how much of what antibiotic to give in different scenarios. Pretty much everything listed here is based directly off of SCIP (Surgical Care Improvement Project) guidelines, which is considered the national standard. Some institutions and surgeons, however, have certain antibiotics, doses, or dosing schedules they prefer (usually still within guidelines), so always be sure to double check with the surgeon prior to administration. 

Below you will find tables showing which antibiotics are acceptable to use in different surgeries, their doses, and how often they should be re-dosed.

Anti-microbial agent	Adult Dose	Pediatric Dose	Redosing Time
Ampicillin	2g	50mg/kg	2 hours
Cefazolin (Ancef)	1g,2g, 3g (over 120kg)	30mg/kg	4 hours
Cefuroxime	1.5g	50mg/kg	4 hours
Cefotaxime	1g	50mg/kg	3 hours
Cefoxitin	2g	40mg/kg	2 hours
Ceftriaxone	2g	50-75mg/kg	NA
Ciprofloxacin	400mg	10mg/kg	NA
Clindamycin	600mg, 900mg	10mg/kg	6 hours
Fluconazole	400mg	6mg/kg	NA
Gentamycin	5mg/kg	2.5mg/kg	NA
Levofloxacin	500mg	10mg/kg	NA
Metronidazole (Flagyl)	500mg	15mg/kg	NA
Vancomycin	15mg/kg (usually in 0.5g incriments)	15mg/kg	12 hours

Type of Surgery	Prefered Antimicrobial	If Beta-Lactam Allergy
Cardiac & Vascular	Cefazolin	Clindamycin or Vancomycin
Colon	Cefoxitin	Flagyl or Cipro
Gen. Surgery	Cefazolin	Clindamycin or Vancomycin
Gynecological Procedures	Cefoxitin	Flagyl & Gent; or Flagly & Cipro
Neurosurgery	Cefazolin	Clindamycin or Vancomycin
Orthopedic	Cefazolin	Clindamycin or Vancomycin

All antibiotics listed, with the exception of Vancomycin (2 hour window), should be administered within a 1 hour window prior to surgical incision. Within half an hour is considered even better. If the dose is prior to the one hour window, discuss with your surgeon and attending about giving another dose.

Try and commit the more commonly used antibiotics to memory: Ancef, Vancomycin, Clindamycin

    

A few good useful pieces of information to know about antibiotics:

1. Antibiotics are one of the more common medications that patients have immune-mediated reactions to – rash, pruritis, bronchospasm, anaphylaxis.
2. Certain antibiotics, most notably Vancomycin, can cause non-immune mediated histamine releases, triggering symptoms that look very similar to an anaphylactic reaction. To avoid this with Vancomycin, put in a 100cc or 250cc bag of NS and run in over an hour. You will come across a number of antibiotics in our career, many that you are unfamiliar with. If you are unsure whether or not to run it in slowly, check the vial or contact the pharmacy.
3. You will often come across surgeons and anesthesiologist that like to avoid Cephalosporins (such as Ancef) in patients with Penicillin allergies because concerns of cross reactivity. The truth is, there is a very low incidence of patients having an anaphylactic reaction to cephalosporins with a penicillin allergy. However, it is still reasonable to avoid in these situations.   
4. Some antibiotics can cause ototoxicity (issues with your hearing) – particularly Vancomycin and Gentamycin.
5. Some antibiotics can be nephro-toxic – ie. Gentamycin. 

Commonly Used Drug Infusions

Before even arriving at CWRU-MSA Houston, everyone is assigned a drug card with doses and concentrations of drugs you commonly encounter in the OR. This card is very helpful for an extended period during your training, however, it is just a starting place. One thing that is not featured on the card that you commonly encounter in the OR are drug infusions. This is a basic tutorial that goes over some commonly used infusions, mostly pertaining to Memorial Hermann. It will also cover the concentrations and dilutions that are used for these infusions and how to do a basic setup with an Alaris pump. You may not encounter all of these early on in your training, but this can be a helpful tool to refer back to.

Pay close attention to the units. Most infusions will be run on a mcg/kg/min dose range with a few exceptions.  

Sedatives:

• Propofol: Sedative-hypnotic agent that works through positive modulation of the GABA neurotransmitter.
• TIVA: 100-200mcg/kg/min 
• In these cases, for one reason or another, you are not running any volatile anesthetic. Propofol will generally be the main hypnotic agent making up for the lack of volatile. Dosing range varies on a number of factors including age and what other IV sedative/analgesic agents you are running.
• Mild sedation: 25-75mcg/kg/min.
• This dose range is seen in certain cases such as colonoscopies and EGD’s. At Hermann and the DDC, however, pumps are not used and the drug is titrated by hand.
• Neuro cases: 25-75mcg/kg/min
• In many neuro cases, propofol is run in addition to half a MAC of gas and a narcotic infusion. Necessary for intracranial surgery with necessary management of ICP and spine cases in which the surgeon is using neuro monitoring (SSEP’s & MEP’s).
• Dilution: You can get 50ml or 100ml vials of propofol from the Pixis or pharmacy that come in 10mg/ml concentrations. No need to dilute. Just spike bottle and set to pump.

• Precedex: Alpha-2 agaonist. Used in numerous settings. You will most commonly see it in the OR used for awake fiberoptic intubations, smoothing out the patient emergence, and running as an infusion along with a narcotic and half a MAC of gas during neuro cases (often in cases treating epilepsy where propofol is contraindicated because it hinders surgeon analysis of epileptic foci in the brain).
• Initial Bolus: 1mcg/kg over 10 minutes.
• Infusion: 0.2-0.7 mcg/kg/hr
• Dilution: Precedex usually comes in one of two concentrations: The first is a 50ml bottle from the pharmacy @ 4mcg/ml. No need to dilute this bottle. Just spike bottle as is and hook to the pump. The second is in a 2ml vial @ a concentration of 100mcg/ml (a total of 200mcg per vial). Take these 2 mls and dilute into a 50ml bag of NS to get a final concentration of 4mcg/ml.  

 Pain Control:

• Ketamine: Works really well for pain control, particularly in patients that take chronic pain medications or abuse narcotics. At pain level doses, I have never run into any issues with hallucinogenic side effects. Also works well to bolus the agent at around these same doses.  
• Infusion: 0.2-0.5mg/kg/hr
• Concentration: Can find in the pharmacy in either 10mg/ml, 50mg/ml or 100mg/ml concentrations. For bolus dosing, I generally like a 10mg/ml concentration. For infusions, I recommend diluting down to 1mg/ml in a 50ml or 100ml bag of NS. 

• Remifentanil: Narcotic with a potency approximately 2X that of fentanyl. Virtually no context sensitive half-life. Will NOT provide analgesia following case, in fact, patients may experience hyperalgesia. Good for cases when surgeon needs to perform post-op neuro analysis of patient. Usually run in addition to propofol and half MAC of volatile.
• Infusion: 0.1-0.3 mcg/kg/min
• Dilution: Comes in a powder 1mg/vial. Mix either 1 or 2 mg in a 100ml bag to make a concentration of 10mcg/ml or 20 mcg/ml 

• Sufentanil: Narcotic with a potency 10X that of fentanyl. Has a longer context sensitive half-life than that of remifentanyl and shorter than that of fentanyl. Probably the most commonly used at Hermann because it provides some post-op analgesia. Usually run in addition to propofol and  half MAC of volatile.
• Infusion: 0.1-0.3 mcg/kg/hr
• Dilution:  Comes in a 2ml glass vial at a concentration of 50mcg/ml (a total of 100mcg per vial) Dilute into a 100ml bag of NS to a concentration of 1mcg/ml. Other institutions will have to dilute to a 5mcg/ml concentration so that a 1ml bolus will be the same as a 1ml bolus of fentanyl.

Vasopressors:

In most situations when using vasopressors and anti-hypertensives, you will generally start on the lower end of the dosing range and titrate up as needed.

• Phenylephrine: Primarily alpha agonist activity.
• Infusion: 0.15-0.75mcg/kg/min
• Many institutions are fine with you making a 250ml bag @ 40mcg/ml and hooking up to a 60 dropper IV tubing and titrating with the roller clamp by hand. Don’t try this at Hermann, however, you’ll likely get in trouble.
• Dilution: 10mg into 100ml or 250 ml bag to make either 100mcg/ml or 40mcg/ml concentrations.

• NorEpinephrine: Alpha and beta agonist activity, but more alpha than beta.
• Infusion: 0.05 – 0.5 mcg/kg/min or 2mcg/min – 10mcg/min (this dosing seen more at other institutions).
• Dilution: 1 mg into 100ml bag = 10mcg/ml or 4mg into 250ml bag = 16mcg/ml

• Epinephrine: Alpha and beta agonist activity
• Infusion: 0.05 – 0.5 mcg/kg/min or 2mcg/min – 10mcg/min (this dosing seen more at other institutions). 
• Dilution: 1 mg into 100ml bag = 10mcg/ml or 4mg into 250ml bag = 16mcg/ml

• Vasopressin: Vasopressin is one of the few drugs that regardless of which institution you are in will not be dosed on a per kg basis. Works well in the setting of sepsis, when patients have taken ARB’s or ACE inhibitors on the morning of surgery, and in patients with pulmonary HTN (causes limited pulmonary vasoconstriction in comparison to peripheral vasoconstriction).  
• Infusion -  1 Unit/hr – 4 Units/hr
• Dilution – In many hospitals, you can get a 50ml bag @ 1 Unit/ml concentration from the pharmacy. If not, it will come in a 1cc vial @ 20U/ml. Take 5 ml (a total of 100U) and put into a 100ml bag to make a 1U/ml concentration.

• Dopamine: The function of dopamine is very dose dependent. Below, different infusion rates are labeled with their associated functions.
• Infusion:
• Improved renal function(??): 0.5-2.5mcg/kg/min
• Beta activity: 2.5-10 mcg/kg/min
• Alpha & Beta: 10-20mcg/kg/min
• Dilution: 400mg/250ml, 800mg/250ml, 800mg/500ml – All pre-made bags from pharmacy.

Anti- hypertensives:  

• Nicardipine: Calcium channel blocker. Primarily a vasodilator. Does not depress HR, cardiac contractility or suppress electrical activity in the nodes of the heart. Longer acting than NTG.
• Infusion: 1-4mcg/kg/min
• Dilution: 25 mg into a 250ml bag = 100mcg/ml. Usually pre-made by the pharmacy.  

• Nitroglycerine: Primarily causes venous vasodilation.
• Infusion: 0.5 – 2mcg/kg/min
• Dilution: 50mg in a 250ml bag = 200mcg/ml. Generally in pre-made bottle or bag by pharmacy.

Setting up the Pump:

Reading the pump set up on its own really isn't all that helpful. Take some time to play around with the pump when you are actually in the OR. They are not difficult to use, however, it may take a little time and experience getting used to it. If you can pull this up on your phone, it can be a helpful guide in walking you through the step-by-step process. Not every  institution uses the Alaris but many do and it's a good place to start in learning on how to operate pumps in general.

A Alaris pump that is turned off is pictured below. To power it on, simply hold down the "System On" button that is located near the bottom right hand corner of the screen. You may need to hold it for a few seconds until the screen comes on. This would be a good time to make sure that the pump is plugged in as well. Sometimes it will alarm at you if it is not and the battery reaches a low level.

As the machine powers on, the first screen will ask you if it is a new patient. Press the arrow button located next to the "Yes" icon. After this, it will ask if this is critical care. Again, press the arrow key next to the "Yes" button again. The next screen will prompt you to enter a patient ID. This isn't an important step, so without entering anything press the arrow key at the bottom of the screen that points to the "confirm" button.

At this step, the pump is technically ready for you to start hooking up drugs and programming infusion rates, but first I want to show you a few things that will make life easier before we move on. To start, we are going to switch the pump into anesthesia mode. This mode allows us to access more drug profiles and will not alarm at you if a channel is paused for an extended period. To switch into anesthesia mode, press the "Options" button near the bottom left hand side of the screen. Next, press the arrow button that points to the "Anesthesia Mode" icon. From here, press the arrow key next to the "Enable" icon, followed by the arrow pointing to the "Confirm" icon. This will take you back to the home screen.

One more step until we get to the infusion programming. We are going to want to turn down the alarms volumes. The default setting is quite loud and can be annoying to both you and the surgical team. In turning down the volume, you can still hear it, but it won't be as much of a bother. From the home screen, press the arrow at the bottom of the screen next to the "Audio Adjust" icon. At the next screen, press the arrow button next to the "softer" icon until the volume appears to be at its lowest setting. Once you have done this, press the arrow near the "Main Screen" icon to return to the home screen.

Finally, we are ready to start programming our infusion. There are a number of drugs already programmed in the pump. We will use propofol as our example since it is one commonly used infusion. Programming for other drugs/infusions will essentially be the same with a few subtle differences, so you should be able to use this example in other scenarios.

Begin by pressing the one of the "channel select" buttons on one of the physical pump channels. Either A or B will work, depending on which one you want to start with. Press the arrow key next to "Guardrail Drugs". This will access the drug library already programmed in the pump. You can see a number of drugs in here. To find Propofol, press the arrow key next to the "P-T" icon. The drugs will be organized in alphabetical order. If you don't initially see your drug of choice, you may need to use the "Page up" or "Page down" icons at the bottom of the screen to scroll through your options. Next, press the arrow key next to "propofol." Since this is a commonly used drug at a certain concentration, it is already programmed in the pump and can be seen on the next screen. Some drugs may have multiple options or you may need to manually enter in the concentration. Confirm by pressing the arrow next to the "yes" key.

The pump will then prompt you for the patient weight. Enter is in kg using the number keypad and then press the "next" arrow. The next screen will ask for a VTBI = volume to be infused and the rate at which you want to run the infusion. Use the arrow keys next to each choice to highlight your selection and enter the associated values. For this example, I have entered 100ml VTBI, a common size of propofol vial, at a rate of 50 mcg/kg/min. When ready, hit the "Start" key followed by the "pause" button on the pump channel.

Now the pump will be ready for use as soon as we hook up the IV tubing. An example can be seen below of how to hook up the tubing properly to the pump. Once latched in place, if you press the "Restart" button on the pump channel, the infusion will begin to run at the settings you programmed earlier. Now you're ready to roll.

Note: you can program the pump before or after putting in the IV tubing, the order doesn't really matter. I just chose to program it before placing the tubing in this example.

Pediatric Quick Guide

This is a brief guide that is by no means a comprehensive review of pediatric anesthesiology. It should merely be used as a starting point if you are new to pediatric anesthesia or need a quick refresher if it has been some time since your last pediatric cases. Let’s get started.

Patient Weight

A good number of things in pediatrics are weight based. It is important to find out the patient’s weight as soon as possible, as it will greatly help you in setting up for the case. It can clue you in to what size airway device you will use, doses of drugs to draw up, how to set the ventilator, and how to properly manage the patient’s fluids. You may not always have access to the patient’s weight prior to setting up the room, but if you know his or her age, you can usually make a pretty close estimate using the following equation:

Weight (kg) = ((age in years)x2)+9

What if your patient is under 1 year of age? This is a valid question and the equation doesn’t really work in these situations. Below is a list of correlating ages in months and their associated weight. There really isn’t a good way to remember these, you just have to memorize them. As with the equation above, it may not always be entirely accurate, but it provides a good starting point for your room set up.

New Born = 3.5kg

3 months = 6kg

6 months = 8kg

9 months = 9.5kg

12 months = 10kg

Airway Devices

Now that we have a good idea about how much our patient weighs, we can choose a proper airway device. As with adults, this will vary depending on what type of case you are doing. There are a wide variety of ETT and choosing the correct size is very important. The following equations will help determine what we need to use. In addition to this, sometimes the package will be labeled with the appropriate age or weight.

Cuffed ETT size = ((Age/4) +4) – 0.5

Uncuffed ETT size = (Age/4) +4

Most of the time at Memorial Hermann, you will be using a cuffed tube. At Hermann, the staff will expect that you have ready a half size above and below the predicted size, just in case. Do not open the ETT until you get instructor approval, unless you feel confident in your size choice.

Again, you’ll notice that this equation doesn’t really work for ages under 2 years old. Below are the correlating ages and weights for children under 2.

Premie = 2.0

Term New Born = 2.5

1-6 months = 3.0

6-18 months = 3.5 -4.0

18-24 months = 4.0-4.5

Whichever ETT size you decide on, secure at a depth of 3 x (ETT internal diameter)

Choosing a properly sized blade can be just as important as choosing the correct size ETT. Different attendings sometimes will have different preferences, and there isn’t always a correct choice. This will give you a starting point until you decide which blades you are most comfortable with.

Up to 3 months = Miller 0

3-18 months = Miller 1

18 months – 3 years = Mac 1 or Wisc 1.5 or Miller 1.5

3-5 years = Mac 2 or Wisc 1.5 or Miller 1.5

>5 years = Miller 2 or Mac 2-3

Most of the time with LMA’s, the proper weight range is listed on the package. With different manufacturers, I’m sure this isn’t always the case. Below is a table showing how to properly choose an LMA size.

LMA Size	1	1.5	2	2.5	3	4	5
Weight (kg)	0-5	5--10	10--20	20-30	30-50	50-70	70-100

Common Medication Doses

In most instances, at least for outpatient surgery, pediatric patients will present to the OR without an IV. Unlike adult patients, it is not something that they can tolerate in the pre-op holding area. Before starting an IV, you have a few options for mask induction. Adding different smell flavors to the mask can be very helpful (cherry, grape, strawberry, etc.)

• 70% O2 and 30% N20 – Have the patient breathe this while you start the IV. They will not be completely asleep, but will be sedated/more relaxed. Usually works best for slightly older children that tolerate the mask well and can tolerate some pain from the IV.
• 70% O2 and 30% N20, slowly work up on Sevo up to 8% on dial – Will eventually put patient completely asleep before starting the IV. BMV support may be needed when asleep. Again works well in children that don’t fight the mask being placed on his or her face.
• 70% O2 and 30% N20, Sevo set at 8% on dial – Will quickly get patient completely off to sleep. Works well for patient that are combative when mask is placed on face.
• 100% O2 with Sevo turned to 8% on dial – also quickly works to put patient to sleep. Sevo doesn’t have sweet smell, like N20, so patient often fights mask away.

Premedication – These drugs can be very helpful in making for a smooth transition into the OR and performing a mask induction. Many are taken by mouth since no IV is often available.

• Midazolam – 0.5mg/kg PO, 0.1mg/kg IV
• Ketamine – 2-3mg/kg IM

Commonly used IV meds in the OR –

• Propofol – 2-3mg/kg
• Lidocaine – 1mg/kg (Many people do not give lidocaine upon induction)
• Fentanyl – 1-2mcg/kg
• Rocuronium – 0.5-1mg/kg

• Decadron – 0.1mg/kg = antiemetic; 0.5mg/kg – airway edema
• Zofran – 0.15mg/kg
• Toradol – 0.5mg/kg
• Ofirmev – 10-15mg/kg
• Morphine – 0.05-0.1mg/kg   

               

• Neostigmine – 0.03-0.07mg/kg
• Glycopyrolate – 0.01mg/kg   

   

• Ancef = 30mg/kg q6
• Vancomycin = 15mg/kg q12

Emergency Drugs – In some institutions, it is common practice to have these drugs drawn up in their proper amounts for each case. Others just prefer that they are available. Regardless, I suggest that when starting out that you have the doses calculated out and know exactly how much volume of each to give in an emergency situation. Being in an emergency situation in pediatrics can be stressful enough as it is without having to do math in your head on the fly.

• Succinylcholine – 1-2mg/kg IV, 4mg/kg
• Generally we try to avoid sux in pediatrics because it can cause associated bradycardia and can trigger hyperkalemic cardiac arrest in patients with undiagnosed muscular dystrophy.
• Atropine  - 0.01-0.02mg/kg IV, 0.02-0.03mg/kg IM
• Epinephrine - .01mg/kg = vasopressor, .03-.3mg/kg = Cardiac arrest  

Vent Settings

At Memorial Hermann when manually ventilating the patient, you will most commonly use Pressure Control Mode. You will adjust the pressure accordingly to deliver tidal volumes in the range of 6-10ml/kg for the patient. This is generally safer than using Volume Control Mode, in which it you may accidentally deliver a larger than intended tidal volume and pressure, causing damage to the lungs. Pressure Support mode can also be very helpful.

Fluid Management

Being that some pediatric patients have such small circulating blood volumes, close attention must be paid to managing fluids. Just as in adults, similar equations can be used to estimate circulating blood volumes and allowable blood loss.

Circulating Blood volume:

                Preemie: 100ml.kg

                Term New Born: 90ml/kg

                6 months: 80ml/kg

                1 year: 75ml/kg

                Teens = 65-70ml/kg

Allowable blood loss = CBVx(((Hct-pre)-(Hct-post))/(Hct-pre))

At Memorial Hermann, all fluids are managed using an Alaris pump. This is an extra safety precaution to ensure that you don’t accidentally give your patients too much fluid. Once the IV is started and connected, a 10ml/kg bolus is usually given to combat the hypotension associated with beginning a general anesthetic. Throughout the case, you may give more of these boluses to help treat hypotension.  

Following initial blood loss, fluid is maintained using the 4-2-1  hourly rule in addition to closely following blood loss and urine output.

4-2-1 hourly maintenance:

                4ml/kg for first 10kg

                2ml/kg for second 10kg

                1ml/kg thereafter

For PRBC’s, 10ml/kg will raise the hematocrit by about 3%.


Table Setup at Memorial Hermann

PEDIATRIC GETA SETUP

Drug cart setup for pedi GETA

Alright so now things get a little more tricky. Some of you will do pedi cases pretty early on and the setup is quite different. In most instances you will be asked to prepare syringes and get drugs out but to not draw anything up. The main difference in pedi is that you use a syringe that gives an appropriate single dose for the patient and you always make an epinephrine bag/syringes. Here are the contents of a GETA pedi drug setup.

1. Atropine - comes in this box from the cassette. Just have it out and on the table.
2. Epinephrine in a 100 cc NS bag. Epi comes 1 mg/ml and is diluted to 10 mcg/ml. Then you will draw it up in a 1 cc syringe and a 3 cc syringe (unless you have a small, small child in which case 1 cc syringe only, will do).
3. Epi - 1 cc syringe.
4. Propofol - 10 cc syringe. Again, it can be done in any syringe and the choice is based on the size of the patient and the dose of the drug. Don't worry, you will learn this.
5. Fentanyl - 3 cc syringe. Same "rule" as propofol
6. Rocuronium - 3 cc syringe. Repeat?

Your first days in pedi will be a little overwhelming and the setup and drugs are a big part of that. The idea is to draw up only the amount you would need for a single dose for the patient as to avoid overdosing them. For now this is slightly above and beyond for you all, don't stress.