Premedication and Early Sedation

Premedication Goals

• Modern premedication aims to relieve anxiety using Benzodiazepines (-zolams).
• Further goals include sedation and analgesia.
• Premedication helps prevent nausea, vomiting, and allergic reactions.
• It reduces gastric fluid volume and acidity and improves coagulation.
• Premedication attenuates autonomic reflexes.
• Be cautious that patients may need to complete preoperative history and physicals or answer questions and sign documents.
• Some patients may wish to ask questions preoperatively.

Early Sedation

• Midazolam (BZD --> GABAa) is given orally or rectally and has little effect on respiration when given with Tylenol, but cause sleepiness for a long period afterward.
• Ketamine (CCB/NMDA antagonist), given orally or IM, provides sedation and analgesia; post-anesthesia delirium is less common in children, but there may be prolonged emergence.
• Dexmedetomidine (Alpha 2 agonist) given IV or intrabuccally (in pediatrics) decreases post-operative pain.

Ketamine Pre-op

• Oral or IM ketamine provides sedation and analgesia that is dose-dependent.
• Ketamine is associated with post-anesthesia delirium, which is less common in children, and may prolong emergence.
• IV or IM ketamine results in rapid onset, dissociative anesthesia, sedation, and analgesia.
• Ketamine acts as an antidepressant and is useful in pediatric and trauma/hypovolemic cases.
• It also provides post-op pain control via infusion and maintains airway reflexes.
• Ketamine indirectly releases catecholamines, resulting in less drop in blood pressure compared to propofol.
• Ketamine directly depresses the heart and is synergistic with GABA agonists.

Contraindications of Depressant Meds

• Relative contraindications include newborns (

ASA Physical Status Classification

• The ASA (American Society of Anesthesiologists) status classifies physical status, not risk.
• It provides a simple description of a patient's condition used for comparing groups in studies.
• It only deals with physical status and does NOT include the current procedure being undertaken.
• ASA 2 includes patients who have asthma but it is under control.
• ASA 3 means their asthma is not under control.
• ASA 4 indicates a constant threat to life.
• ASA 5 means the patient is dying.
• If a patient has heart failure, move them from ASA 3 to ASA 4.

Steroid Use and Surgery

• Patients who have had steroids recently may have impaired adrenal function.
• Usually receive 100mg IV hydrocortisone pre-anesthesia and 100mg every 8 hours
• There is a risk of acute Addisonian crisis with refractory hypotension.
• If the steroid use was longer than 2 weeks in the past few years, give a hydrocortisone supplement because the body can't produce enough cortisol on its own.

Management of Pre-Op Meds

• Important to note the following medications
• For diabetics: give one half usual dose of insulin in AM.
• Hold oral hypoglycemic agents (metformin) due to increased stress hyperglycemia.
• Hold GLP-1 drugs, including semaglutide, tirzepatide, dulaglutide, and liraglutide.
• Stop SLGT-2 drugs 3 to 4 days before the procedure, including empagliflozin and dapagliflozin.
• ACEIs (-pril) and ARBs (-sartan) should be held, but other antihypertensives are typically okay for pre-op.
• If opioid analgesics are anticipated post-op, stop naltrexone 3 days prior to surgery.
• Make arrangements for patients on methadone maintenance.
• Psychiatric medications are okay except for MAOIs; SSRIs and ketamine can usually be continued.
• Anticoagulants and antiplatelet medications a big issue, and you must note NOACs, Coumadin, Aspirin, and NSAIDs.

Supplemental Oxygen

• Supplemental oxygen given to reduce ventilation in sedation and anesthesia.
• This is done because it can cause a diminished response to hypoxia and hypercarbia.
• Reduced muscle tone can lead to reduced tidal volume and possible obstruction.
• Everyone who gets sedation/anesthesia gets supplemental O2, pre and post the procedure.
• Examples of supplemental oxygen are nasal cannulas, HFNC (High-Flow Nasal Cannula), and masks.
• All of these devices can be used in a conscious/responsive patient, with no special expertise required.
• None of these devices significantly increase tidal volume, actively remove CO2, or treat obstruction.

Upper Airway Obstruction

• Interventions to relieve obstruction
• The Chin lift pulls the tongue forward away from the throat.
• The Head tilt lines up the oral, pharyngeal, and laryngeal axes, creating a straight path for airflow.
• Use Jaw thrust if suspect cervical injury, pull tongue and soft tissue forward avoiding cervical spine extending.
• Oral Airway for unconscious patients without a gag reflex.
• Nasopharyngeal Airway for conscious patients that have an intact gag reflex.

Endotracheal Intubation

• After successful endotracheal intubation, check bilateral breath sounds and look for absent sounds in the stomach (maybes).
• Look for chest wall movement and vapor in the ETT (maybes) and expired CO2, which is gold standard.

Signs of Upper Airway Obstruction

• Sings of obstructions include Rocking boat movement.
• Accessory muscles start to work harder and the clavicle becomes prominent with inspiration.
• Note any Rocking chest motion (chest falls + abd rises → opposite of normal) where Diaphragm descends maximally pushing abd contents up and Negative pressure without air coming into the chest cavity.
• Nasal flaring can also indicate obstruction.
• Faint/absent breath sounds can also indicate obstruction.
• Cyanosis is a late and unreliable and indicates O2 saturation is < 85%.

Ambu Bag

• To ventilate properly, note these Bag-mask ventilation caveats
• Proper mask seal is imperative
• Don't press too hard on the patient's face
• Don’t fight the patient’s ventilation
• Once the airway is established from previous interventions, use the ambu bag to attach the mask to the face, valve helps create pressure, The Self-inflating bag supplies the O2 reservoir , and tubing helps you connect to the O2 source

Difficult Airway Signs:

• The inability to see the airway can be caused by
• Having a Short mento-hyoid or mento-thyroid distance.
• Prominent maxilla
• Immobility of TMJs
• Inability to fully open mouth
• Long overriding incisors
• Limitations of neck extension/flexion
• Or having a thick neck
• If you can’t intubate and can’t ventilate use
• FONA – Front of Neck Airway
• Cricothyrotomy and a Tracheostomy / Tracheotomy
• Note the Mallampati score should be noted to see describes/predicts intubation difficulty during pre-op, III or IV indicates difficult intubation.
• The Cormak Lehane grades describe the view you have when performing direct laryngoscopy to insert a breathing tube and if it is a III or IV then this will be a difficult intubation.
• Grade 1: see everything
• Grade 2: see vocal cord
• Grade 3: see the hood of epiglottis
• Grade 4: cannot see epiglottis

Rapid Sequence Induction (RSI)

• Performed if intubation has been unsuccessful.
• Prepare by providing Preoxygenation and then proceed with Hypnosis/sedation then administer a Muscle relaxant and perform the Laryngoscopy for Intubation.
• Keep in mind that RSI has a higher rate than conducting normal induction.
• Consider RSI in any patients at risk for aspiration and include:
• Those that are Pregnant
• Obese Patients
• If the Patient has recently fatty meal
• Trauma patients
• Patients with any reasons for Delayed gastric emptying like:
• Bowel obstruction
• Acute abd
• Narcotic usage
• Patients that has also recent Pt has also swallowed a gastrograffin (constant), or bleeding in mouth, oropharynx, or upper GI.
• Increases risk if Aspiration injury (prevention)
• The main risk is with induction securing the airway with RSI and can lead to Aspiration pneumonia.
• Most serious cause is Aspiration of particulates causing mortality or Fecal aspiration causing the highest mortality (particulate + bacteria) and if not prevented can lead to Alveolar capillary breakdown that will lead to Interstitial edema, Intra-alveolar hemorrhage, Atelectasis leading to and Increased airway resistance and leading to eventual Hypoxia.

Steps to Prevent Aspiration

• Administer and use a H2 blocker to decrease the production of gastric acid in addition to a Gastropropulsive agent (metoclopramide) (avoid using of course if GI obstruction is present).
• Use an antacid ( Non-particulate) comprised of : BicitraⓇ or Sodium Citrate buffer during emergency situations.
• Use a Rapid sequence induction with cricoid pressure

Cardiovascular Complications and Prevention

• These are a direct result of general anesthesia and commonly lead to Atelectasis. In order to prevent hypoventilation a few things you can do is be aware of:
• Worsend V/Q mismatches and is more common for shunt post-op, prevent /treat from this is to implement and mobilize patient and teach them how to use an incentive spirometer
• Other signs include cardiac issues like Hypo/Hypertension and Arrhythmias or Perioperative myocardial infarction and or lastly Thrombo-embolic phenomena or significant fluid shifts.

At-Risk Aspiration and Bronchospasm Patients

• Pregnant women from the second semester.
• Obese Individuals
• Pts who have recently eaten (esp. Meals high in fat)
• Pts that have swallowed Gastrograffin
• Pts w/ delayed gastric emptying (bowel obstruction, acute abdomen, ileus, narcotic use, etc.)
• Pts that are Trauma patients or have Bleeding into the mouth, oropharynx, or upper Gl tract.

At-Risk Bronchospasm Patients

• Pts that are known to have Asthma or COPD, or have a History of smoking and/or if they have a resent/concurrent Resp Infections.
• You will see an inflamed, hyperreactive airway/environment caused by these cases.

Anesthesia-Induced Hypotension

• Primarily is caused by dec'd Cardiac output (CO)+Systemic vasular resistance (SVR), but can also come from Hypovolemia .
• Chronic hypotension can cause labile BP. The same can be said if an anaphalaxis and fluid shift happens as well as Cardiac.
• MI-> low BP Rapid fluid shift -> low BP

Post op hypoventilation

• Hypoventilation is defined as:
• Related to meds: opiates, NMB (decrease ventilation)
• Relate to pain: pt doesn’t wanna breath/ “splinting” (decrease breathing hypoventilation) Very common - see in the recovery room (give nasal cannula)

Closing Capacity Note

• Closing capacity increase in children (60) compared to FRC functional residual capacity which mean every time they inhale -> airway closes causing Increased atelectasis and increased V/Q mismatch that worsens post-op atelectasis, leading to problems during ventilation.
• This leads to patients having to put in more effort into inhalation known as their Resp Muscles. This in turn then Dec their Resp strength (inc wall compliance plus less recoil, no pump handle movement all due to abdominal contents that are hindering any chest movements which lead to dec’d Min ventilation, in return inc RR compensation that then does Dec closing volume- this leads to air trapping that worsens V/Q mismatch of gases that is ultimately caused by atalectasis)

Cardiac and Cardiac Functions

• Cardiac muscle in children is known to be weaker that is resistant to venous return cause of heart muscle
• Limited stroke volume is cause of 2 things
• Cant increase SV response to demands cause heart depend on Heart Rate Bradycardia -> low CO due to < 60 beats Hypoxia is big demand for babies . 3.Hemocrat levels a.Separation of blood components i. Packed Red Blood Cells (PRBCs)

1. 250-350 ml Hgb increases approx. 1 gm.dl

• Hct increases approx. 3 pt who is not bleeding out Plasma (FFP)
• 200-300 ml Plasma protein
• Many clotting factors Cryoprecipitate i. 10-20 ml Fibrinogen, factors VIII and XIII
• Platelets Usually comes as a pool from 5 or 6 units Heart increase is significant for new borne

Pre Op for Pediatric patients on certain medication

• Fasting, give clear fluids that ensure clear juice and Gatorade to ensure clear
• Give the pre Op
• 4 Breast Milk and Infant
• Normal Fasting Schedule for all of those
• Breast Milk and Infant should be light given and have less fats

Notes on Trauma

• Make note is Mass Transfusions that might cause bleeding- here’s what to do
• Give one unit FFP for every 4 units of PRBC
• Give red cells plasma.

Tips for Infants from Transfusion

• Try to maintain constant body temperature
• Avoid letting body drop as heat loss increases
• Hypoxia due to heat lost cause cardio demand
• Decrease in the the amount of subcutaneous fat
• Impaired body to ability to shiver due muscle growth cause infants use brown fats

Trauma

• One unit for every four units of PRBC and platelets a ratio of 1:1:1:Initial testing with viscoelastic tech and a more modern approach

Notes for Transfusions

• Check for Transfusion Reaction which affects lung injury
• TRAIL transfusion acute lung
• Leadin cause death when that usually occurs because of RCB increase with neutrophils

Risk Factors for Chronic Pain

• Preoperative anxiety can cause patient to feel pain
• Depression
• severe acute postoperative pain lasting up to 5 days
• Long inference with activities
• Smoking or substance use
• Lack of proper support