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Critical Incidence. By : Azhar Faruqi Mohd Rasani Supervisor : Dr NORASLAWATI BINTI RAZAK. Madam N, G1 P0 at Date + 1 day No known medical illness antenatally just had one episode of albuminuria at 17W with UTI symptoms treat as UTI BP normotensive all over the pregnancy.
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Critical Incidence By : AzharFaruqiMohdRasani Supervisor : Dr NORASLAWATI BINTI RAZAK
Madam N, G1 P0 at Date + 1 day • No known medical illness • antenatally • just had one episode of albuminuria at 17W with UTI symptoms • treat as UTI • BP normotensive all over the pregnancy
presented to hospital dungun on 10/5/14 with • -severe headache for 3/7 • +occipital headache • +neck pain • +vomitting x6 • +fever for 3/7 a/w chills and rigor • +left side body weakness for 1/7 • +numbness • no fitting episode • no hx of trauma • then was referred to HSNZ for suspected encephalitis
on examination • GCS 14/15 (e4v5m5) • orientated to time place and person • look drowsy • +left facial assymetry • +neck stiffness • bilateral pupil reactive and equal 2mm • Gag reflex present • bp 143/73 • pr 80 • t 37.7
cns examination • right side • both upper and lower limbs normal • power 5/5 • normal tone • reflex brisk, babinski equivocal • left side • hypotonia • power 4/5 • reflex brisk, babinski equivocal • Impression at this time space occupying lession, tro intracranial bleeding • Then proceed with CT brain plain
ct brain -rtfrontotemporalintraparenchymal with intraventricular extension with significant mass effect • abg : respiratory alkalosis • (ph 7.5 pco2 23 pos2 123 hco3 20.7) • was electively intubated for respiratory alkalosis and going for OP • premedication - given iv fentanyl 50mcg, iv midazolam 5mg, iv scolene 50mg • intubated with ETT size 7mm anchored at 20cm • start on sedation iv midazolam 2mls/hr • then was sent to OT for EMLSCS + rt decompression craniectomy + EVD left side
in OT was induce with sevoflurane gases and oxygen • iv esmeron 50mg • then connect to ventilator VC • VT 400 , rate 12, peep 4, I:E 1:2 • maintained with sevofurane • intra operative given • iv fentanyl 100mcg • iv morphine 3mg + 3mg + 2 mg • EBL for emlscs - 500mls • baby was born flat, intubated and was sent to NICU • able to extubate after arrive at NICU • and was put under headbox oxygen
after EMLSCS proceed with neurosurgery operation • intraoperative findings • two yellowish soft tumour 3x3cm surrounded by blood clots • blood clot evacuate 40cc • pulsatile brain • pre op pupil rt 2mm lt 2mm • post op pupil rt 4mm lt 3mm • done rt craniotomy + evacuation of clots and tumour • EBL 700mls
intra op given • 2 pint WB • 6 pints NS • started on iv noradrenaline single strength 2-5mls/hr • ABG at 7pm • ph 7.31 pco2 35 po2 257 so2 99 be -7.4 hco3 18.5 • lactate 1.1 • ABG at 10pm • ph 7.22 pco2 40 po2 200 so2 99 be -10 hco3 16.2 • lactate 2 • post operation was sent to ICU for weaning • not for CP
over the night was sedated on mida morphine infusion • next morning GCS 11/15 • obey command • abg good on CPAP mode • then was extubate to VMO2 • and was sent to radiology department to repeat CT brain • repeated CT brain
Learning Issues • Decision regarding intubation • Physiological changes in pregnancy
Objective measures indicating the need for intubation • -RR > 35bpm • - VC < 15ml/kg • - PaO2 < 60 • - PaCO2 > 50 (except in chronic retainers)
Indications: • For supporting ventilation in patient with pathologic disease: • Upper airway obstruction, • Respiratory failure, • Loss of consciousness • For supporting ventilation during general anaesthesia: • Type of surgery: • Operative site near the airway, • Thoracic or abdominal surgery, • Prone or lateral surgery, • Long period of surgery • Patient has risk of pulmonary aspiration • Difficult mask ventilation
Decision to intubate Maintaining airway? Airway manuevers, Adjuncts no Now maintained? Intubate yes yes no Protecting airway? yes Ventilating / oxygenating adequately? yes Deterioration / airway compromise likely? Consider intubation vs. close observation Rapid transport yes no Supp. O2, Observe, Transport
The changes in maternal homeostasis a/w pregnancy – adaptive & useful to the mother in tolerating the stresses of pregnancy, labour & delivery • It involved (virtually every organ system) -hormonal changes –physiological preparation for pregnancy (after ovulation) progesterone -↑ of bld volume meet the metabolic demand following conception • Maternal physiological changes return to normal following parturition
Anatomy • vertical measurement of the chest as much as 4 cm • results from elevated position of the diaphragm • its contraction not markedly restricted • AP and transverse diameter (2-3 cm) • in the subcostal angle from 68.5 to 103.5˚ at term as a result of flaring out of lower ribs • in thoracic cage circumference by 5-7 cm (early pregnancy) • Changes produce by relaxin (secreted by corpus luteum) that relaxes the ligamentous attachments of the ribs
Anatomy (Upper Respiratory Tract) • Hyperemia & edema induced by estrogen • Nasal stuffiness & epistaxis • Capillary engorgement throughout the resp. tract (nasal, oropharyngeal mucosa & larynx), vocal cord may be swollen or edematous
Anatomy • Airway conductance - indicates dilation of larger airway below the larynx • Factors contributing to airway dilation : • Direct effects of progesterone, cortisone & relaxin • Possibly enhanced -adrenergic activity induced by progesterone
Mechanics of breathing 1. Dilatation of large airways 2. No change in max. expiratory flow rate (PEFR) 3. No change in forced expiratory volume in 1 sec (FEV1) 4. No change in ratio of FEV1 to FVC 5. Flow-volume loops are unaffected & airway resistance decreases
Lung volumes & capacities • Tidal volume: 40-45% • with approx. half of the change occurring during the 1st trimester • This early change is a/w a reduction in Inspiratory Reserve Volume (IRV) • The changes during the later half is accompanied by a decline in FRC & increased in IRV • Chest wall compliance & total lung compliance decrease 30% increase in minute volume (50%)
Lung volumes & capacities FRC : 20% begins by 5th month of pregnancy caused by elevation of the relaxed diaphragm occurs as the enlarging uterus enters the abdominal cavity ↓ by 20% at term contributed by 25% reduction in ERV & 15% reduction in RV Return to normal 48H post delivery Decrease in FRC d/t reduction in ERV as a result of larger than normal VT
Lung volumes & capacities • Inspiratory capacity 15% • during the 3rd trimester because of the in VT and IRV • Vital capacity & closing capacity is unchanged • because of corresponding in ERV • Total lung capacity ↓ slightly (0-5%)
Lung volumes & capacities • minute ventilation by 45-50% results from in VT • alveolar ventilation by 45% -hormonal changes Progesterone & Estrogen - CO2 production -PaCO2 is closely related to the bld level of progesterone • this hormone the sensitivity of the central resp center to CO2 & acts as a direct resp stimulant
Anatomical dead space unchanged (until late pregnancy upper airway edema-reduction) Physiological DS decreases but intrapulmonary shunting increases towards term VD/VT ratio unchanged ↓ dead space narrows the arterial end-tidal CO2 gradient CXR: prominent vascular markings d/t ↑ pulm bld volume & an elevated diaphragm
Elevation of the diaphragm decreases the volume of the lungs in the resting state, reducing TLC by 5% and FRC by 20% • FRC mainly decreased by RV • Vital capacity does not change • Spirometry is not changed in pregnancy • FEV1 is unchanged • Peak flow is unchanged
paCO2 by 15 % • Decrease to 28-32 mmHg • Due to resp.alkalosis -every 0.13kPa increase in pCO2,ventilation increase 6 l/min compare non-pregnant 2 l/min -compensates by ↓ plasma[HCO3] • Hyperventilation increase PaO2 slightly • During 2nd and 3rd trimester • Progesterone enhance the response of the resp. centre to CO2 • ODC curve shifted to Rt (rise in 2,3 DPG)
paO2by 10 % • results from in paCO2 and arteriovenous oxygen difference, which reduces the impact of venous admixture on the paO2 • O2 consumption(Vo2) increases 250-500ml/min
Arteriovenous oxygen difference - smaller in early pregnancy because in CO is greater than the in O2 consumption - as pregnancy progresses, O2 consumption continues to while CO to a lesser degree, resulting in decreased mixed venous O2 content and increased AV O2 difference
Anaesthetic Implication • Rapid alveolar & arterial hypoxia during periods of apnoea / airway obst. d/t combination of FRC & O2 consumption -adequate preoxygenation • Easily atelectasis & hypoxemia when in supine position closing volume > FRC -O2 supplement during supine • Accelerate the uptake of all inhalational agent combination of FRC & minute ventilation -MAC by 15-40%
Anaesthetic Implication • As a result of capillary engorgement of the mucosa: • ↑ risk upper airway trauma, bleeding & obstruction apply gentle laryngoscopy & use smaller ETT • ↑ risk URTI can further compromised the airway • Avoid nasotracheal intubation • Mallampati score
Examination of the heart • Grade 1 or 2 early to mid (ejection) systolic murmur is commonly heard at the left sternal border • D/t cardiac enlargement, which results in dilation of tricuspid annulus that causes regurgitation • ECG –Lt axis deviation, flattened/inverted T-waves, occasionally ST depression CXR • appearance of enlarged heart d/t elevation of the diaphragm, shifts the heart’s position
Cardiac Output • accompanied increase the bld volume (to meet the metabolic demand) • reaching 35-40% (1.5 L/min) by end of 1st trimester • continues to till 3rd trimester, until reaching 44-50% as a result of increase in HR (15-20%) and SV (30%) • Double during labour esp. 2nd stage • May further increase immediate post delivery (d/t autotransfusion) • Return to normal after 2 wks post delivery
Cardiac Output • decrease in CO in supine position after 28th week of pregnancy, 2° to impeded VR as the enlarging uterus compresses the IVC • At 38-40 weeks, there is a 25-30% fall in CO when turning from the side to the back
Stroke volume • approx. 20% between 5th and 8th week of gestation • by 25-30% by end of 2nd trimester till term • CVP, PA and PCWP • similar to nonpregnant levels (relaxant effect of progesterone on the smooth ms)
SystemicVascular Resistance SVR is reduced during pregnancy average SVR in pregnancy is about 980 (1150 dynes.s cm−5 in non-pregnant women) Decrease in SVR results from development of a low-resistance vascular bed (the intervillous space) & vasodilatory effects of oestrogens, prostacyclin & progesterone
Regional blood flow • Uterine blood flow • before conception from 50-190 ml/min, to 700-900 ml/min at term • 90% perfuse the intervillous space with the balance to myometrium • Skin perfusion • begin to at 15 wks of gestation, reaching to 3-4 times the non-pregnant level at term • Results in an skin temperature • Blood flow to brain & liver do not change
Distribution of CO • First trimester and non-pregnant state • Uterus receives 2-3% • By term • Uterus receives 17% • Breasts 2% • Reduction of the fraction of CO going to the splanchnic bed & skeletal ms • CO to the kidneys, skin, brain and coronary arteries does not change