Remember most of changes are directed to prepare the mother to meet increased demands and progesterone is the harm alone responsible for many changes
1. GI- reduced lower GI tone , increased chances of reflux due to gravid uterus pressing on stomach- more pronounced after 12 weeks- so after 12 weeks it is better to do rapid sequence induction. Institutes routinely prescribe antacid prophylaxis to women presenting for surgery after 12 weeks if elective-po ranitidine, ranitidine takes around 60-90 minute for full action
Emergency - sodium citrate
The idea is that if the women aspirates during induction acidic contents will do more harm than neutral. Older notion was that upto 40 % parturients have more than 40 cc of gastric content with ph<2.5- this notion is being challenged but I would use antacid prophylaxis as the drugs are relatively benign.
Remember mortality is around 40 percent if one lobe is involved and upto percent if more than one lobe is involved- it has improved in the age of I phones
2. Hematological- RBC volume increases by 30 percent while plasma volume increases by around 45 percent so there is hemodilution so Hb concentration decreases. Clotting factors 11 and 13 decrease, 2and 5 remain same all others increases.
Total Plasma protein concentration decreases , albumin decreases and globulin and fibrinogen increases so edema is normal finding in pregnancy.
Pseudocholinesterase levels reduce by 20-25% though effect of scolding is not clinically increased.
Remember maternal hemorrhage is the most common cause of maternal mortality worldwide nature acts by hemodiluting blood and increasing coagulatability. On the other hand increased coagulability have increase chances of PE in pregnancy
WCC increases and increases to 15000 during labor.
3. Cardiac- cardiac output increases to 50 % mainly due to increase in stroke volume (30 %) and increase in HR(20-25%)
In pregnant patients worrying bradycardia is HR less than 60 opposed to 40 in non pregnant
C.O = HR times Stroke Volume
Reduced SVR due to progesterone , reduced systolic and diastolic bp
Remember cardiac output increases in left lateral position to about 14%
EKG- left axis deviation, st depression, T wave inversion in lead III,LVH is common
Grade 1-2 mid systolic murmur is common due to tricuspid regurgitation
Aortocaval compression- compression of aorta and inferior vena cava in supine position can cause hypotension after 18 weeks so wedge is applied during cesarean section to tilt the uterus to left.
4. Respiratory - increased tidal volume, MV increases by 50 % so hyperventilation produces
Respiratory alkalosis with mild hypocapnia with increased PO2
Reduced FRC 30 %combined with increased oxygen demands warrant meticulous per oxygenation
prior to GA.
Capillary engorgement of airway with airway edema due to increased plasma volume and reduced plasma protein increase the incidence of difficult airway in pregnancy and they bleed more on repeated attempts do laryngoscopy.
5. Renal- increased GFR reduced the amount of urea and creatinine in pregnant patients.
6. Nervous system
MAC reduces by 35-40 percent but ensure sufficient anesthesia
Engorgement of epidural veins reduce the dose of epidural or spinal drugs.
Increased sympathetic nervous system activity which is maximal at term so epidural or spinal anesthesia By producing sympathetic block produce more pronounced hypotension.
7. Endocrine: increased TBG require increased dose of levo thyroxine in hypothyroid patients,
Insulin resistance due to increased levels of HPL , prolactin .
1. GI- reduced lower GI tone , increased chances of reflux due to gravid uterus pressing on stomach- more pronounced after 12 weeks- so after 12 weeks it is better to do rapid sequence induction. Institutes routinely prescribe antacid prophylaxis to women presenting for surgery after 12 weeks if elective-po ranitidine, ranitidine takes around 60-90 minute for full action
Emergency - sodium citrate
The idea is that if the women aspirates during induction acidic contents will do more harm than neutral. Older notion was that upto 40 % parturients have more than 40 cc of gastric content with ph<2.5- this notion is being challenged but I would use antacid prophylaxis as the drugs are relatively benign.
Remember mortality is around 40 percent if one lobe is involved and upto percent if more than one lobe is involved- it has improved in the age of I phones
2. Hematological- RBC volume increases by 30 percent while plasma volume increases by around 45 percent so there is hemodilution so Hb concentration decreases. Clotting factors 11 and 13 decrease, 2and 5 remain same all others increases.
Total Plasma protein concentration decreases , albumin decreases and globulin and fibrinogen increases so edema is normal finding in pregnancy.
Pseudocholinesterase levels reduce by 20-25% though effect of scolding is not clinically increased.
Remember maternal hemorrhage is the most common cause of maternal mortality worldwide nature acts by hemodiluting blood and increasing coagulatability. On the other hand increased coagulability have increase chances of PE in pregnancy
WCC increases and increases to 15000 during labor.
3. Cardiac- cardiac output increases to 50 % mainly due to increase in stroke volume (30 %) and increase in HR(20-25%)
In pregnant patients worrying bradycardia is HR less than 60 opposed to 40 in non pregnant
C.O = HR times Stroke Volume
Reduced SVR due to progesterone , reduced systolic and diastolic bp
Remember cardiac output increases in left lateral position to about 14%
EKG- left axis deviation, st depression, T wave inversion in lead III,LVH is common
Grade 1-2 mid systolic murmur is common due to tricuspid regurgitation
Aortocaval compression- compression of aorta and inferior vena cava in supine position can cause hypotension after 18 weeks so wedge is applied during cesarean section to tilt the uterus to left.
4. Respiratory - increased tidal volume, MV increases by 50 % so hyperventilation produces
Respiratory alkalosis with mild hypocapnia with increased PO2
Reduced FRC 30 %combined with increased oxygen demands warrant meticulous per oxygenation
prior to GA.
Capillary engorgement of airway with airway edema due to increased plasma volume and reduced plasma protein increase the incidence of difficult airway in pregnancy and they bleed more on repeated attempts do laryngoscopy.
5. Renal- increased GFR reduced the amount of urea and creatinine in pregnant patients.
6. Nervous system
MAC reduces by 35-40 percent but ensure sufficient anesthesia
Engorgement of epidural veins reduce the dose of epidural or spinal drugs.
Increased sympathetic nervous system activity which is maximal at term so epidural or spinal anesthesia By producing sympathetic block produce more pronounced hypotension.
7. Endocrine: increased TBG require increased dose of levo thyroxine in hypothyroid patients,
Insulin resistance due to increased levels of HPL , prolactin .
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