Anesthesia and comorbidities Flashcards
what are the effects of DM on CVS
- Myocardial infarction
- Hypertention
- iscahemic heart disease
- Cardiomyopathy
- Cerebrovascular acccident
What are the effects of DM on the Nervous System
Increased risk of stroke
autonomic and peripheral neuropathy
What are the effects of DM on Respiratory system
increased risk of perioperative chest infections
Effectsof DM on GIT
Gastroparesis-reflux
effects of DM on renal
increased risk of renal failure
effects of DM on musculoskeletal
Stiffening of ligaments around the joints leading to limited mobility and cause proteolysis which affects wound healing
In a patient with DM what’s important in preop assessment
FBC
HBA1C
U&Es
Cr
ECG
Urine protein
intra op what’s the blood glucose level are we targeting
6 and 8
which group is treated as minor surgery
if the patient is expects to eat within 4 hrs of the operation
management of well controlled dm/minor surgery/normal fbs
Non insulin dependent diabetics:
First on the list
Omit oral hypoglycemics
Blood sugar monitoring:
- 1 hr pre-op
- at least once intra-op or every hour if procedure extends more than an hour
Post op 2 hourly until eating, then 8 hrly
Insulin dependent diabetics: type 2/type 1
First on the list
Omit normal sc insulin if glucose<7mmol/l
Give half normal insulin if glucose > 7mmol/l
Blood sugar monitoring:
- 1 hr preop
- atleast once intraop
-Post op 2 hourly until eating, then 4 hrly
Restart normal sc insulin with first meal
management for major surgery
Plan includes patients for minor surgery whose admission blood glucose is > 7mmol/dl
Check blood sugar and potassium pre-op
Omit oral hypoglycemics or normal sc insulin
Start on IVF
Start IV insulin sliding scale (in the ward)
Blood glucose measurement:
-2 hourly from start of sliding scale
- hourly intraop
-Hourly post op until 4 hrs then 2 hrly.
PERIOPERATIVE RISKS ASSOCIATED WITH SEVERE UNTREATED HTN
Associated with serious post op complications e.g MI, Cerebral hemorrhage/infarction, renal failure
PRE-OP CONSIDERATIONS TO MAKE in a patient with HTN
Is the HTN primary or secondary?
Is the surgery urgent or not?
Is regional anaesthesia possible for the proposed surgery or not?
Does the patient have any evidence/signs of end organ damage?
Stage 1 and 2 HTN should not be delayed surgery
Pre-op antihypertensive management need not to be interrupted except for the following medications:
ARBs
ACE inhibitors
ISSUES TO CONSIDER WHEN ADMINISTERING ANEASTHESIA TO EPILEPTIC PATIENTS
Many antiepileptic drugs induce liver enzymes that can lead to reduced activity/ duration of action of anaesthetic drugs
Avoid hyperventilation as it leads to hypocarbia causing reduced blood flow
Avoid prolonged starvation to minimize metabolic disturbance
DRUGS TO AVOID IN EPILEPTICS
Ketamine due to dissociative anesthesia
Propofol thought to cause postoperative seizure-like activity ( controvesial)
Methohexitone- related to Thiopentone but precipitates seizures in epileptics
ANEASTHETIC DRUGS OF CHOICE IN EPILEPITICS
Thiopentone- can be used for status epilepiticus as well
Majority of inhalation agents except Enflurane
in an asthma patient during preop assessment its important to ask ..?
Ask about triggers including drugs eg. Aspirin, latex products
Exercise tolerance
Signs of URTI- may need to postpone elective surgery if present.
Last acute attack/admission
INVESTIGATIONS ini asthma patient preoperatively
Peak flow: Serial measurements are more informative than a single reading
Response to bronchodilators
Spirometry
Blood gases in severe asthma particularly prior to major surgery
what drugs should be avoided in asthma patients
Avoid drugs associated with histamine release ( morphine, atracurium, mivacurium
PERIOPERATIVE RISKS IN POORLY CONTROLLED ASTHMATIC PATIENTS
Have increased risk of:
-bronchospasms
-sputum retention
-atelectasis
-infection
-respiratory failure
Need to ‘hold’ elective surgeries until the patient is stable
SAFE ANAESTHETIC DRUGS IN ASTHMATICS
Induction agents- Propofol, Ketamine, Midazolam, Etomidate
Opioids-Pethidine, fentanyl, alfentanyl
Muscle Relaxants- Vecuronium, suxamethonium, rocuronium, pancuronium
Volatiles- Halothane, isoflurane, enflurane, ether ( Nitrous oxide
