Maternal Anatomical and Physiological Changes During Pregnancy

Maternal anatomical & physiological changes 1rst lecture Anaesthisiology/ 4thstage By dr. Amassi Yakdhan 2022 - 2021

Which body systems affected during pregnancy Respiratory system RS Cardiovascular system CVS Central nervous system CNS Renal system Endocrine & immun system Coagulopathy & haematology Gastrointestinal system GIT Muscloskeletal

Key points These changes happen because of increase O2 demand& to hold the baby Surgeries could be obstetrical & non obstetrical during pregnancy Keep in mind the current medical disease Some medical diseases start symptoms at pregnancy Some hidden medical diseases aggrevate during pregnancy

Respiratory system Capillary engorgement of mucosa lined the RS by effect of estrogen Nose , pharynx , larynx all affected by this engorgement Easy to bleed by touch There will be O2 demand & metabolic rate So O2 consumption & Co2 production Fluid retention ; so tounge swelling Lung compleince shifting of gravid uterus to the diaphragm

Respiratory system Ventilatory mechanics : Functional residual capacity Minute ventilation . Respiratory rate R.R Tidal volume Tv Mv = RR Tv FRC Mv

Respiratory system Why pregnat can get easy atelactasis ? Because FRC woleb ro raen gnieb CC Closing capacity ,so closed during Tv Rv residual volume reduced O2 demand % 75 _ 40%

Cardiovascular system Aortocaval compression : C.O.P cardiac out put HR heart rate SVR systemic vascular resistance Pressure of gravid uterus on aorta & inferior vena cava IVC enipus no yam neht , P.O.C decuder neht traeh ot nruter suonev ecuder ot dael noitisop htaed ot hcaer dluoc taht noisnetopyh reves ot dael

Cardiovascular system How you avoid aortocaval compression ? Avoid supine position ,by keep the patient on lateral side or keeping a pillow under right side flank What are the other C.V.S changes ? 1. Shifting the heart appex toward the up right that change in ECG readings 2. Tachycardia because of O2 demand

Coagulopathy & haematology Physiological anemia : lead to dilutional aneamia , false anemia RBC up to ot pu emulov amsalp eht & % 50 % Hypercoagulobility : so risk of thrombosis , embolisim ,DVT niev peed) ot pu ( sisobmorht 7 days after labour. emulov amsalp to double & RBC the same , 20

Gastrointestinal system Patient is consider as full stomach ,RSI rapid sequance induction Affect the tone of sphinectors , so gastric refux is common Delay gastric emptying intra abdominal pressure , so risk of pulmonary aspiration

Why pulmonary aspiration is common on pregnancy ? Reduce lower esophageal sphincter tone intra abdominal pressure Delay gastric emptying acidity of gastric juice

Central nervous system Engoregment of pelvic venous pleuxes cerebral blood flow permeability of blood brain barrier Pain threshold MAC to 30%

Some tricks Why in neuraxial anesthesia need low dose ? Because engoregment of pelvic pluxeses due to pressure of gravid uterus on inferior vena cava ,so anesthesia stay more longer in site

Renal system GFR glomerular filtration rate glucoseuria & protienuria , so low seurm protien ,so increase binding to anesthetic drugs become more ) propofol , pentothal , benzodiazepine ( Hydronephrosis , hydroureter due to gravid uterus pressure effect. Incontinence , frequancy, nocturia & infection

Endocrine Hypo or hyper thyroidism Gestational diabetis DM Hypoglycemia

Muscloskeletal Progesteron effect lead to relaxant of joints = dislocation in neck joints during flexion & extension positioning during GA Skin edema = fluid retention & obesity Gestational skin allergy & secondary bacterial infection

Why neurexial anesthetic technique is more difficult in pregnancy Obesity & Skin edema Over lordosis skin edema & thickness cause difficult canulation skin thickness

Causes of difficult airway management Large edematous tounge Short obesie neck Difficult manipulation of head & neck joints Large breast

Why pregnant easy get hypoxia Currant disease lung compliance by shifting effect of gravid uterus Difficult airway management ) intubation & or ventilation ( Obesity & large breast FRC , Rv , O2 demand & metabolic rate

What you should keep in mind in pregnant anesthesia Full stomach RSI should keep in mind Difficult airway management Difficult neuraxial anesthesia Difficult cannulation Easty get hypoxia Easy get hypotension Easy get hypovolaemiac Currant or coexisiting disease Pregnancy induced hypertension Pre eclampsia & eclamptic fit DKA sisodicaotek citebaid PPH & APH & egharromeah mutrap tsop egharromeah mutrapetna Dealing with 2 spirit Top emergency could considered by mother or baby Gastric aspiration

What are tricks for pregnant anesthesia Its emergency surgery RSI Prepare for difficult airway management Neuraxial better that GA Large bore cannula because bleeding is common at any time Awearness is common Death for baby or mother at any moment N2O is agood choice

Why awearness is common in pregnant anesthesia Stress of mother O2 consumption & BMR Limitting the rule of sedative pre medication Rapid up take & elemination of volitale (N2O + O2 ) 50% + volitale 50% is a good choice for GA Sedative opioid or benzodiazepine after delivery of baby Regional is the best way for anesthesia

The end Closing capacity Cc = the volume of gas at wich alveoli start to collapse Rv + Cv = Cc Residual volume + closing volume = closing capacity