Four limb leads + V5 (left anterior axillary line, 5th ICS), allows monitoring of 7 leads simultaneously.
– V5 is 75% sensitive for detecting ischemic events; II + V5 is 80% sensitive; II + V4 + V5 together is 98% sensitive.
BP Cuff too small
falsely HIGH BP
A-line Transducer Setup
Zeroing = exposes the transducer to air-fluid interface at any stopcock, thus establishing Patm as the “zero” reference pressure.
Leveling = assigns the zero reference point to a specific point on the patient; by convention, the transducer is “leveled” at the right atrium.
point at end of expiratory plateau
gradual expiratory upstroke, shortened plateau
INCREASING BASELINE on Capnogram
faulty expiratory valve
inadequate inspiratory flow
insufficient expiratory time
CO2 absorber malfunction
max pressure per breath
volume controlled modes
AC: Assist Control. You set the volume and the rate. The patient always gets this. If the patient tries to inhale the machine also will deliver a breath “assist”.
SIMV: Synchronized Intermittent Mandatory Ventilation. You set the rate and the volume and also pressure support. Typically set the rate low to encourage patient to breathe. Extra breaths are supported by the pressure you preselect and the ventilator synchronizes breaths with the patient.
Pressure Control Mode.
Set rate & maximum peak airway pressure allowed. Tidal volumes vary in accordance with the pressures
Set pressure support
patient does all the work
Ventilator gives this set pressure to augment what the paitent is doing.
Useful for weaning.
Set a backup breath every 30 seconds or patient will get nothing if they don’t breathe.
Continuous Positive Airway Pressure
Constant set pressure in cm H2O to the patient.
The patient exhales against this.
Positive End Expiratory Pressure.
Leaves a little positive pressure behind at the end of expiration.
Useful for preventing atelectasis and increasing oxygen levels as alveoli remain open.
big breath every few minutes.
Helps prevent atelectasis and mimics natural breathing.
shorten it to 1:1 if you are having problems with CO2 retention esp. in laparascopic surgery.
Beware air trapping.
COPDers like 1:3
monitoring nondepolarizing NMBA
number of twitches and the ratio between the 4th
and 1st twitch are measured with the TOF.
TOF Surgical relaxation can be achieved when the patient has
2-3 twitches depending on location
Nerve stim setup
red proximal to heart
Four patterns of electrical stimulation:
Single Twitch – a single pulse 0.2 msec induration given every 1 -10 secs
Train of Four (TOF) – a series of fourtwitches given within 2 secs, each 0.2 msecin duration
Tetany – a sustained 5 sec stimulus of 50to 100 Hz
Double Burst – three stimulations followedby two stimulations, each set separated by750 msec
Sensitivity to NMBs
Laryngeal muscles (VC)------most resistant
monitor arm or orbicularis
Reversal of NMB is accomplished by using an
standard test of normal clinical function (NMB reversal)
A sustained head lift for 5 secs remains the
TOF ratio > 0.7
N.B. Neostigmine will potentiate
phase I block from sux
but will reverse a phase II block
If placing electrodes on the face, do not deliver more than
20 – 30 mA or you will stimulate facial muscles directly
Perform your induction with higher doses of narcotic and lower doses of propofol. This serves two purposes.
DL will cause an exaggerated sympathetic response with tachycardia and hypertension that may be severe. Blunt the patient very, very well with narcotic and lidocaine and limit DL time (15 seconds or less).
Beware of blood pressure dropping during lull times in the case. Fluid load the patient, don’t be afraid to switch to colloid and keep phenylephrine/vasopressin and ephedrine close at hand.
Blunt the patient very well before incision.
Watch your EKG closely for ST changes.
During the case, keep the patient’s MAP where it was at baseline. Remember your patient has “upregulated” to this MAP.
Do not lower the MAP to where you think it should be. You may think you are doing the patient a favor. You are not. You risk loss of perfusion to organs, MI and stroke, or POCD if you do.
Beware of hypertension which may be severe during emergence as the patient begins to awaken, feel pain, and buck.
Narcotize the patient as well as you can to avoid pain.
Deep extubate if you can to prevent bucking, or blunt with an LTA.
Coronary artery disease mgt
12 lead EKG if your patient is over 40 or has drug habits.
keep HR, BP within 20% of normal
sedate before emergence
Blunt the patient very well with midazolam and narcotic. Use as little propofol as possible. Avoid ketamine.
Don’t hesitate to start a phenylephrine drip.
Use a non depolarizer, no sux please.
Blunt the patient well before DL, and limit to 15 seconds or less.
Yes you can give them nitrous. Do if possible. More nitrous=less inhalational.
Regional is always an option if the case is appropriate. Spinals are best avoided.
Use non depolarizers as needed.
Please use the ST segment analyzer function on the monitor and keep an eye on it.
Keep your patient warm. Shivering increases myocardial oxygen demand
Reversal of paralysis needs to be done carefully to prevent tachycardia.
Deep extubate your patient if possible or blunt with an LTA to avoid bucking.
Narcotize the patient well.
Nitroglycerin boluses are your friend for the treatment of hypertension on emergence. It will drop BP nicely and quickly, wear off right away and will not affect the heart rate. Plus they dilate coronary vessels.
Please order a 12 lead EKG in the PAR. Keep oxygen on longer.
Mitral Stenosis mgt
Plan for an arterial line.
Goals are “fast, forward, full”.
Do not let the heart rate decrease.
Maintain normovolemia as much as possible. In both cases, try not to overload but under-rescuscitation is very bad.
Keep phenylephrine handy: try not to allow any decrease in SVR. This is very bad for aortic stenosis as the coronary arteries will not perfuse if this happens.
Use more narcotic and less propofol.
The mitral valve is incompetent, does not close fully and blood flows backwards into the left atrium.
You will see signs of left atrial enlargement on the 12 lead EKG.
You will see an enlarged heart on the CXR.
General anesthesia is preferable.
Regional in the form of peripheral nerve blocks is probably ok if MR is mild to moderate. Spinals and epidurals are not recommended d/t sympathectomy.
Maintain the heart rate as much as possible. Some decreases in PVR benefit the patient, but there are limits.
Deep GA can maintain the decreased PVR you want. Blunt the patient well with narcotics to avoid swings from surgical stimulation.
Aortic Regurgitation mgt
The incompetent aortic valve allows blood to fall back into the left ventricle at end diastole.
Will cause LV hypertrophy and increased oxygen demand by the heart.
These patients often have angina—coronary arteries don’t perfuse well.
You will need a medical or cardiac consult to determine level of optimization.
Plan for an arterial line.
Maintain the heart rate as best you can.
Again, regional is best avoided if AR is severe. You can decrease PVR, this will help the patient, but don’t overdo it.
Mitral Valve Prolapse
Left ventricle contracts and incompetent valve leaflet falls backwards into the left atrium.
Present in 5% of the population.
When listening you will hear a click type murmur.
You need to maintain normovolemia. If you don’t you risk permanent prolapse of a leaflet during LV contraction.
Keep the patient’s SVR at baseline in this case.
Please no regional of MVP is severe: its effects on PVR.
Place an arterial line, awake if necessary
Keep the patient’s heart rate at baseline, avoid tachycardia.
Blunt the patient very well with narcotic, lidocaine, etc. to avoid overtly sympathetic responses to DL or surgical stimulation.
Keep phenylephrine or vasopressin handy.'
It is best not to take these patients to surgery if possible.
CHF must be under tight control and patient must be optimized. Medicine/cardiology must be involved.
Anesthetic goal is to preserve cardiac output to the highest degree possible
Place an awake arterial line with sedation and local.
Induction generally speaking has to be done with midazolam/fentanyl only, and maintenance may have to be done with opioid drip and low dose gas.
You will have to put them on the ventilator, they won’t be able to breathe for themselves. Warn them they might wake up still on the ventilator.
Keep fluids to the bare minimum and keep lasix handy.
Patient history is the best indicator. Chest X rays are rarely helpful.
Ask patient for severity. Ask how often uses inhaler, how many ER visits, hospitalizations, or admissions.
If asthma is severe ie has had admissions, intubations or placed on ventilator, a medicine consult is probably warranted for optimization
Listen to the lungs day of surgery. If surgery is elective and patient is wheezing, cancel case.
Remember that in most cases, the mere act of instrumenting the airway (intubation) can and often does trigger bronchospasm.
Regional anesthesia is a good option whenever possible!
Use regional anesthesia.
Don’t intubate (LMA).
Pre emptively treat asthmatic patients with albuterol.
Sedate them well before bringing back.
Turn on sevoflurane quickly while inducing.
Blunt airway with LTA.
Once tube is in, turn on sevoflurane quickly. Listen for wheezing right after taping tube. If you hear wheezing or if peak pressures are high, give more albuterol. Remember most of it is going to stick to the tube so plan accordingly.
Keep patient as deep as you can on sevoflurane during case.
Deep extubate the patient if you possibly can. You really should.
Give albuterol again before you shut off the agent.
Blunt the carina again with an LTA.
Post Induction Bronchospasm
Try to prevent it by following the steps above. Some things are better to prevent than to treat.
Severe post induction bronchospasm can be hard to diagnose!!! If they are that tight you will not see much end tidal and you might not hear any breath sounds!!
If you are 100% sure you saw the tube go through the cords don’t take it out
Give more albuterol. Remember most of it is going to stick to the plastic so plan accordingly.
Turn up the agent: hand bag the patient.
If all else fails, give a little epi.
Loss of elastic recoil of the lungs. The patient can’t exhale.
PFTs may or may not help you. A history is just as good.
Assess exercise tolerance. If poor, then PFTs.
Regional anesthesia, if possible, is a very good choice for these patients
If general anesthesia cannot be avoided, remember these patients are chronic CO2 retainers. Your good intentions can be their worst nightmare.
You cannot let them breathe spontaneously under general anesthesia.
Warn the patient they might awaken still on the ventilator!
Set the I:E ratio on the ventilator from 1:2 to 1:3 or more. Remember they take much longer to exhale than we do.
You have to allow permissive hypercapnea. Remember they have upregulated and a 60/60 ABG is not unheard of in these patients. Don’t try to fix this.
Don’t use nitrous.
Use the least amount of narcotic. Ask surgeon to inject local.
Type 1 diabetes
Assess level of conttol.
Remember hypoglycemia under general anesthesia is extremely difficult to diagnose and the consequence is permanent brain damage.
Tight control is key, 120-180.
Assess for end organ damage
Rule is one year of untreated diabetes ages the vasculature 10 years.
Nephropathy is common, check kidney function tests and plan accordingly.
If neuropathies are present, avoid regional.
Beware of loss of joint mobility from glycolyisation of joints. This includes the neck and the mandible. Have patient show you prayer sign to assess.
Beware of loss of autonomic control in these patients. Resting heart rate tachycardia or a heart rate that fails to respond to exercise is an ominous sign of the beginning of a denervated heart
Delayed gastric emptying is a hallmark sign of diabetes. It is wise to pretreat them with reglan and/or treat them as a full stomach.
Decreased sensation is ubiquitous in diabetes. Silent MIs are not unheard of. Always order a 12 lead EKG.
Hold all PO oral hypoglycemics day of surgery, many say the night before too d/t risk of hypoglycemia in the perioperative period.
Hold morning insulin.
Schedule these patients first. Check their blood sugar morning of surgery.
Don’t hang LR please. NS or Plasmalyte.
Check serum glucose levels priodically.
Obese persons are at great risk for hypertension (increased cardiac output) and cardiomegaly.
Great risk of hyperlipedemia and coronary artery disease.
Abnormal liver function: fatty liver.
Rampant type II diabetes.
Decreased lung volumes and capacities
Chronic hypoxemia and obesity hypoventilation syndrome.
Remember obesity imposes a restrictive ventilation defect in and of itself. Truncal obesity is the worst.
Many obese patients are chronically hypoxic and hypercapnic.
They have no inspiratory reserve.
OSA is rampant.
Make sure your blood pressure fits the patient. Too small and and it will read falsely high.
You can place a regular sized cuff on the forearm.
Obese people often have serious airway issues. Neck ROM and head extension are often limited. Thick heavy neck means redundant tissue which can be very difficult!
Mouth opening may be limited: check.
It is wise to treat them as a full stomach.
Have a low threshold for awake fiberoptic intubation in these patients. Stand your ground if you have to. These patients have no oxygen reserve other than what you give them. If you don’t get the tube in on the first try, things can go very badly.
Have the difficult airway cart ready if you are worried. Call for a glidescope as well.
Avoid sedation. Plan to go very light on the opiates.
Know which of your drugs should be based on ideal body weight and which actual. Plan accordingly.
Regional is always an option but is likely to be difficult.
Do not ever lie down an obese person.
Preoxygenate the patient first. Put the oxygen on right after the pulse ox. Do not begin induction until the FeO2 is 95% or greater. This buys you time!
Ramp the bed with sheets or shoulder rolls. Ear tragus equal to sternum.
Ramp obese patients until
tragus is aligned with sternum
It is safest to induce with sux. Paralysis is going to cause serious lung compression so be prepared. Use less narcotic.
Use desflurane if you possibly can.
Obese patients cannot be allowed to breathe on their own. Keep them on the ventilator.
If it is a laparascopic case, you have many challenges ahead
Turn the agent off early. Be aware that it might take a long time to come off.
Use narcotics very sparingly. Ketorolac is an option!
Place your patient in reverse trendelenburg.
Make sure all NMB is fully reversed.
Beware of stage II breath holding. Use CPAP with your hands if needed.
Extubate fully awake.
Often goes hand in hand with obesity
Very serious problem for all anesthesia providers and patient deaths have occurred.
Patient breathing stops for >10 seconds during sleep due to pharyngeal muscle tone being lost.
Also mandibular defects play a part
Underdiagnosed and undertreated.
Symptoms: frequent awakenings/microawakenings (most not noticed by the patient), heavy snoring and breathing stoppages (noted by spouse), daytime somnolence.
Complications: memory problems, motor vehicle accidents, hypoxemia and hypecarbia, polycythemia, hypertension, pulmonary hypertension and right heart failure.
ASK patients about these symptoms, especially if they are obese, have thick necks, malampatti 3-4 airways and redundant pharyngeal tissue and/or micrognathia!
OSA Anesthetic implications
Warn the PAR. This is where most problems occur.
If the patient is on CPAP, ask them to bring it with them. If they didn’t, ask the PAR to order one for you.
Minimize narcotics. Ketorolac and local anesthesia is your friend.
Think twice about sending the patient home after surgery. Someone should stay with them.
If patient is willing, refer to a sleep specialist.
Delineate: renally impaired versus renally dead.
If on dialysis, should be followed by that service. Schedule elective surgery for the day after dialysis, due to fluid and electrolyte shifts that happen the day of dialysis.
IV access may be difficult. If you absolutely cannot start an IV ask me to show you how to access a dialysis cath.
If they have a shunt leave that arm/leg alone.
#1 cause: hypertension
#2 cause: diabetes
Kidneys are very powerful and will continue to function during these disease progressions unnoticed by the patient.
Anemia also accompanies this, and is worsened by dialysis.
Hyperkalemia is rampant. Renal patients however generally tolerate a serum K of 5.5 with no symptoms.
Check potassium levels morning of surgery. If higher than 5.5 cancel case if it is elective.
Avoid using sux on renal patients if they are on dialysis and K is high.
Regional anesthesia is always the best choice for this patients whenever possible. These patients are very well aware that they cannot metabolize or excrete our drugs.
Limit IV fluids as much as you can.
Best drugs for renally impaired:
Sux or cisatracurium.
Remifentanyl or fentanyl.
Volatiles are mostly OK.
Renally impared Avoid:
Vec/Roc (ok if necessary but they will be paralyzed much longer)
Meperidine/morphine/codeine (toxic metabolites)
Best choice is to postpone any and all elective surgery until the baby is born.
Unfortunately sometimes this is not possible.
In cases of trauma, the pregnancy almost always is lost.
surgery during the second or third trimester, if necessary, poses low risk to the fetus.
Reason: organogenesis is generally done by then.
Beware of inducing preterm labor! Explain this risk to the patient!
OB/GYN will be involved
Cardiac output increases by 50% during pregnancy.
Oxygen reserve decreases dramatically due to a. hypermetabolic state and b. size.
Airway difficulty increases!
Warn the patient about risk of preterm labor.
Have OB/GYN attach a fetal heart monitor. This will go to the OR with you along with a technician/RN who can monitor it.
Nitrous and midazolam are teratogens. Don’t use them.
Pregnant women are “full stomachs”. Treat them accordingly. Give them bicitra.
Use regional if you possibly can.
RSI is best.
If later pregnancy, position her right side up to prevent IVC compression.
Preoxygenate very, very well.
Inhalationals, propofol are OK.
Minimize narcotics. Ketorolac is now considered OK, but ask.