3. General Anaesthetic Goals
• Analgesia, Amnesia, Paralysis
Unconsciousness
• Maintenance of Hemodynamic stability
• Management with Anesthetic agents
4. Use of non anesthetic interventions/Drugs
• Risks and complications during or after
anaesthesia/surgery.
• Related factors
* The health and condition of the patient
(co-morbidities)
* The complexity (and stress) of the procedure
itself
* The anesthetic technique
5. • Hemodynamic management aims at an
optimization of perfusion pressure and oxygen
delivery in order to maintain or restore
adequate cellular metabolism.
•
• DO2 = CaO2 x CO
CaO2 = (1.39 x Hb x O2Sat/100) + (0.003 x PO2)
• Relating Ohm’s law (I=V/R) to flow
MAP = CO x SVR
7. Preload is the ventricular volume at the end of diastole. An increased preload
leads to an increased stroke volume. Preload is mainly dependent on the venous
return. The relationship between ventricular end-diastolic volume and stroke
volume is known as ‘Starling’s law’, which states that the energy of contraction of
the muscle is related/proportional to the initial length of the muscle fibre.
8. Afterload is the resistance to ventricular ejection. Caused by the
resistance to flow in the systemic circulation and is the systemic
vascular resistance (SVR). The resistance is determined by the diameter
of the arterioles and precapillary sphincters; the narrower or more
constricted, the higher the resistance
9. • Contractility describes the ability of the
myocardium to contract in the absence of any
changes in preload or afterload.
• It is the ‘power’ of the cardiac muscle.
• The most important influence on contractility
is the sympathetic nervous system.
10. Inotrope and vasopressor effects
• Based on the
*Mechanism of action
*Receptor sensitivity
*Dosage of the drug
• A inotrope may have varying degrees of
vasopressor effects
• A vasopressor may have varying degrees of
inotropic/chronotrpic effects
• A inotrope may have vasodilatory effects.
21. Ephedrine
• Sympathomimetic, α and β agonist.
• Direct and indirect acting
• ↑BP, ↑heart rate, ↑ contractility,↑CO
• Bronchodilator
• CNS stimulant
• Vasopressor during anaesthesia
• Dose: 3,5,6 mg in increments.
• Tachyphylaxis
22. Vasopressin
• Effects mediated through V1 (V1a in vascular smooth
muscle, V1b in the pituitary gland) and V2 receptors
(renal collecting duct system. V1a stimulation mediates
constriction of vascular smooth muscle. V2 receptors
mediate water reabsorption.
• Vasopressin causes less direct coronary and cerebral
vasoconstriction than catecholamines.
• Dose-dependent increase in SVR.
• Modulates increase in vascular sensitivity to
norepinephrine further augmenting its pressor effects.
• Produce pulmonary vasodilation through release of NO.
• The pressor effects of vasopressin are relatively
preserved during hypoxic and acidotic conditions.
• Dose: 0.01-0.04 U/min.
24. Levosimendan
• Increases calcium sensitivity of troponin C
enhancing ventricular contractility without
increasing intracellular Ca2 concentration.
• Opens ATP dependent K channels in smooth
muscle and myocardial cells- Vasodilatation
and myocardial protective effect.
• Doesnot increase myocardial O2 consumption.
• Inotropic, lusitropic and vasodilatory efects
• ↑ CO, SV ↓ MAP, SVR, LV filling pressures.
• Loading dose: 12mcg/kg over 15 mins
• Infusion: 0.1-0.2 mcg/kg/min.
25. Case 1
• A 46-year-old female operated for perforative
peritonitis in the postoperative ward.She has a
heart rate of 140bpm, a BP of 75/30mmHg,
she is oliguric and has a temperature of
38.7°C. She feels warm to touch with a
bounding pulse. ABG acidotic, Lactates ↑↑↑
26. Case 2
• A 62-year-old man undergoing procedure
under monitered anaesthesia care. Soon after
the administartion of antibiotics patient C/O
difficulty in breathing. O/E widespread rash,
hypotensing, tachycardic, and auscultation
shows extensive wheeze.
27. Case 3
• A 35 year old male posted hernia repair 3rd in
the list. Fasting more than 12 hours. Patient
hypotensing after spinal with 3ml of 0.5%
sensorcaine. Mx?
28. • Calculate the rate in mls/hr of the infusion to
deliver 0.05 mcg/kg/min of 3mg adrenaline
diluted to 50 ml for a 72 Kg patient?
• Multiply the specified dose (in mcg/kg/min)
by patient’s weight (in kg)
• Multiply this number by 60
• Divide this number by the drug dose in the
syringe (must be in mcg)
• Multiply this by total volume in syringe
29. • The key to proper use of inotropes is to first
understand what each drug does, then to
choose those that fit the clinical problem your
patient has, and to set up monitoring for the
patient so they get the right amount of the
right agent.
