Page 740 - ACCCN's Critical Care Nursing

Pregnancy and Postpartum Considerations 717

TABLE 26.4 Clinical relevance of physiological adaptations in pregnancy

Effects of the normal physiology of pregnancy Clinical implications
Cardiovascular system
l Increased likelihood of: l Consider use of thrombophylaxis
l venous stasis
l varicose veins
l deep vein thrombosis
l Increased likelihood of:
l haemorrhoids
l swollen ankles
l Potential for aortal-caval compression from about 20 weeks’ gestation l Avoid nursing the woman flat on her back, e.g. tilt bed if unable to
nurse woman on her side or use pillows/wedges to obtain a lateral
tilt of at least 15° to maintain placental flow, full left lying is best
l CPR and haemodynamic measurements should be done with a
left lateral tilt
l Haemodynamic stability despite large blood loss l Be alert to subtle signs of haemodynamic compromise
l Sudden deterioration
Respiratory system
l Nasal passages more likely to bleed on instrumentation (e.g. nasal l Nasal-tracheal intubation is not usually an option
intubation, nasogastric insertion) l Have a doctor experienced with intubation on hand when a
l More likely to bleed from the gums pregnant woman is being intubated
l More prone to hypoxaemia during apnoea e.g. when being intubated l Ensure that the artificial airway is protected and guard against
l All pregnant women are considered to have a high-risk airway: accidental extubation
l especially if the woman has preeclampsia l Review the ‘failed intubation’ protocol in the ICU
l particularly if the woman is obese l Pre-oxygenate with 100% O 2 prior to intubation or suctioning
l More likely to develop pulmonary oedema unless contraindicated
l Diaphragm raised by about 5 cm l Titrate fluid resuscitation carefully – especially in women with
severe preeclampsia
l Check diaphragm location prior to ICC insertion for haemothorax/
pleural effusion
Gastrointestinal system
l Pregnant woman is more likely to: l Maintain cricoid pressure throughout CPR and intubation until the
l aspirate person obtaining an artificial airway instructs its release
l develop constipation l Chart bowel actions and ensure a bowel management strategy is
l present with advanced signs and symptoms of acute abdomen, implemented
e.g. appendicitis, bowel obstruction l Early consideration of non-obstetric causes of an acute abdomen
l Pregnant women have additional and specific nutritional needs l Consult with a dietician early to ensure that the woman receives
adequate nutrition during ICU admission
Renal system
l Progesterone and relaxin causes relaxation and dilation of smooth l Minimise use of indwelling urinary catheter
muscles l Renal impairment may be signified by lower serum urea and
l Renal calyces and renal pelvis become distended creatinine levels than in non-pregnancy
l Ureters and urethra are elongated, dilated and have reduced l Some glycosuria and proteinuria is normal in pregnancy
peristalsis l The bladder is at risk of traumatic injury in the second and third
l Stasis of urine and increased risk of ascending infection trimesters
l Acute pyelonephritis is associated with preterm labour
l Bladder is displaced into the abdominal cavity after the first trimester

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maladaptation could be the main cause for this superfi- clinical signs, such as hypertension. Other common
71
cial placentation. Placental flow defects are detected as clinical manifestations in preeclampsia include enhanced
early as 12 weeks in some women who go on to develop endothelial-cell permeability and platelet aggregation,
72
preeclampsia. Placental ischaemia and reperfusion with explaining the increased likelihood for oedema and
subsequent oxidative stress have been regarded as major thrombosis. 71
pathogenetic drivers. It is likely that there is an excessive
or atypical maternal immune response to trophoblasts In summary, preeclampsia presents post 20 weeks’
and the disease represents a failed interaction between gestation, but the foundation for the disease relates to
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the mother’s and fetus’ genetic make-up. The excessive abnormal placentation early in the first trimester. Whilst
systemic inflammatory response and associated endothe- a number of ‘biomarkers’ attempting to predict the onset
lial dysfunction and enhanced vascular reactivity, results of preeclampsia have been identified, there is no reliable
in widespread vasospasm which precedes the onset of predictive test in clinical use. 68