Anesthetic Problems & Emergencies: Lecture Notes PDF

Anesthesia 2 -Lecture 2 **Active Technician Roles in Common Anesthetic Problems** - We play a very active role in problem prevention & identification - Must know your skill set, supplies, equipment, drugs & patient status Ask for help or get a second opinion if your unsure - Must...

Anesthesia 2 -Lecture 2 **Active Technician Roles in Common Anesthetic Problems** - We play a very active role in problem prevention & identification - Must know your skill set, supplies, equipment, drugs & patient status Ask for help or get a second opinion if your unsure - Must practice scenarios with staff -- role play emergency situation - VT are very active in resuscitation & all things surrounding it - Maintain adequate supplies for when things break or for high consumable times **Possible Anesthetic Problems** - Cardiac or Resp Arrest - Tachycardia or Tachypnea - Movement - Overdose - MM Cyanosis - Adverse drug affects - Excitatory phase 4 H's & 1P - Hypothermia - Hypoventilation - Hypotension - Hemorrhage - Pain Equipment Complications - BP Cuff errors - Doppler cuff incompatibilities - ECG red dots not sticking - Patient positioning -- cords tangled - Sp02 Y Clip loose - Cuff or ETT deflating **What Can Help Prevent Medical Errors** - Prep & organization - Math is triple checked - Proper MOV cuff inflation - ADS Leak -- Prevent some WAG - Vaporizer test **Responding to an Emergency** - Think before acting, triage what you need to do, know your room & supplies before being faced with an emergency - Crash Cart supplied & ready, daily & after each use - Drug list and supplies up to date - Closed loop communication - Do no harm -- don't panic, deep breaths and maintain clarity - Get others involves -- more brains the better - Post emergency follow up discussion **Causes of Anesthetic Problems** - Human error - Equipment failure - Adverse effects - Increased patient risk [Human Error] - Inadequate training and lack of familiarity with equipment or agents - Failure to obtain adequate history - Failure to perform adequate physical examination - Drug calculation & administration errors - Errors caused by fatigue, haste or inattention - Inadequate care & maintenance of supplies & equipment - Inappropriate operation of equipment - Equipment-related errors **Adverse Effects** Reduce adverse effects at all costs - Choose a protocol suitable for the condition or needs of the patient - Be familiar with disadvantages/adverse effects & contraindications - Balanced anesthesia: multidrug protocols are safer than single drug protocols, & are MAC sparing - Give minimal required amount - Titrate to effect - Adjust inhalant frequently % adjustments and depth assessments **Equipment: ADS Issues** - Equipment failure or inaccuracy - Carbon dioxide absorbent exhaustion - Failure of oxygen supply - ETT blockage - Connections disconnected or kinked - Blocked parts, flutter valves stuck, scavenge not patent [APL / Pop-Off Valve Problems ] - Leaving the pop off valve in a closed position - No tread feature during IPPV - Being distracted and leaving it closed - Breaks in a closed position - Pop off semi-closed - Components within APL are faulty During leak test when you open the APL it should not decompress, if not then there is likely an issue and it should not be used - Sticky spring feature Notice excessive pressure? Rip bag off machine! -- fast solution to saving a life [Vaporizer Problems ] Usually results in delivering too much = overdose - Using the wrong anesthetic agent -- avoidable with key fillers - Tipping the vaporizer, or moving a lot and the agent splashes around - Vaporizer dial becomes stuck or jammed - Vaporizer is overfilled - Two vaporizers used at same time - Oxygen flow rate is less than 0.5L/min for most vaporizers - Not serviced or within delivery specifications (0.2% +/-) **Common Emergencies During Anesthesia** 1. [Animal will Not Stay Anesthetized ] - An inadequate vaporizer setting - Leak around the ETT cuff -- inadequately cuffed or defective -- remember once patient is at plane II check for leaks again as they are more relaxed - Apnea or inadequate tidal vol - Rapid, shallow breathing -- tachypnea Commonly seen in toy dogs and obese animals Or those who are in a light plane or have a lung pathology - A blocked, misplaced or disconnected ETT Blocked tube will increase breathing system pressure but a semi blocked may just feel like there is resistance when giving an IPPV or show a negative breathing system pressure - Confirm that the endotracheal tube is not blocked (try to give IPPV), is in the trachea (ETC02 yes or no), and that the breathing circuit is attached (visually inspect, or low compliance in IPPV) - ETT too small Responding to Inadequate Anesthetic Depth - Be prepared to give injectable anesthetic drugs to keep patient asleep (propofol or MAC sparing agent) - Loose or misassembled, leaks in ADS - Inadequate oxygen flow? - Provide IPPV: Normal? Okay lung compliance? Leaks? - Check vaporizer setting is appropriate and adjust it accordingly - A vaporizer inadequately filled with liquid anesthetic - Re-check the patients monitoring parameters - Consult team for troubleshooting - If non of the previously listed causes are identified, switch the patient to another machine 2. [Too Deeply Anesthetized ] - \< rpm, or very shallow or exaggerated breaths - Hypoventilation - Pale or cyanotic MM - CRT greater than 2 seconds - Bradycardia - Hypotension Weak pulse, systolic blood pressure less than 80mmHg - Cardiac arrythmias - Cold extremities, body temp is often less than 35c - Absent reflexes, including palpebral and corneal reflexes - Flaccid muscles & jaw tones - Dilated pupils, absent PLR, centrally positioned eyes - Immediate decrease the vaporizer setting - Inform the vet - ER? Turn off vaporizer if any signs of anesthetic overdose or CV/Resp arrest & begin to ventilate the animal with IPPV using pure oxygen - Flush system clear of inhalant: first disconnect patient from breathing system quickly, cover breathing hose end, flush system of anesthetic gases out of scavenge (squeeze bag empty too), and reconnect to provide only 100% oxygen - Use of IV fluids, external heat & reversal drugs may be advised - If the veterinarian is not immediately available to assess patients condition, the safest thing to do is assume the patients anesthetic depth is too deep Decrease vaporizer settings while observing the animal carefully for signs of arousal and monitor vitals 3. [Pale Mucous Membranes ] - Preexisting conditions - Blood loss during surgery - Anesthetic agents that cause vasodilation and hypotension, or vasoconstriction - Hypothermia - Pain - Stress Treating - Check depth - Check other vital signs including hr, reps, pulse strength & CRT - Provide IPPV to rule out problems with 02 delivery & confirm 100% 02 supply ok - Does IPPV feel ok/normal? Good or poor compliance - Resp system depression Hypoventilation If hypoventialting on room air = hypoxia Common at recovery if not careful Prevent -- extubate only when ready Provide flow by for 5 mins as they convert back on room air Monitor Sp02 throughout recovery - Rule out possible causes including hypothermia, hypotension, drug reactions and blood loss and pain - Vet should be consulted 4. [Prolonged CRT ] - Blood pressure cannot adequately be perfusing superficial tissues - May result fro conditions present prior to induction - May be secondary to blood loss during surgery - May be seen in animals in deep anesthesia - Immediately check animals pulse and BP - Observe the animal for other signs of shock, including hypothermia & tachycardia (or bradycardia in later stages of shock) - Discuss with DVM 5. [Hypotension ] - Less than 80 systolic - Less than 50 diastolic - Less than 60 mean - ANY of these should be immediately addressed - PREVENTION IS KEY, recognize trends - Pre anesthesia prevention -- minimal use of vasodilation drugs - Recall inhalants cause DOSE dependent vasodilation = hypotension & hypothermia - Optimize pain control with injectable analgesics to reduce inhalants - Several drug options available to stabilize BP - Keep patient warm - If BP cannot be maintained, colloids may be given to concert with crystalloids or blood product if required Treatment - Reduce inhalant -- if patient is not to light, continue until patient shows signs of being light - Fluids -- determine if patient requires CV volume consult with DVM, administer a 10mL/kg bolus STAT - Drugs -- determine if patient requires CV drugs with DVM & administer accordingly RECOVER - D/C Inhalant & detach ADS from ETT and flush system clear on inhalant, only administer 02 - Reverse all agents - Capnography = or \> 15ETC02 goal - May need to add more air to cuff as increased pressure from compressions can cause leak