Monday [12/6/23] Flashcards
how does fludrocortisone work?
acts by increasing plasma volume as a result of its sodium-retaining effects, thus increasing cardiac output. It also acts by potentially increasing sensitivity to sympathetic nerve stimulation, leading to an increase in peripheral vascular resistance
orthostatic hypotension PP
On standing, gravity causes blood to pool in the lower extremities. The autonomic nervous system usually counteracts this by increasing heart rate, cardiac contractility and vascular tone (Freeman et al. 2011). The skeletal muscle in the lower body also contracts to prevent excessive pooling
define orthostatic hypoension
The definition of postural hypotension endorsed by the European Federation of Autonomic Societies is a sustained reduction of systolic blood pressure of at least 20 mmHg or diastolic blood pressure of 10 mmHg within 3 minutes of standing, or of tilting the body (with the head up) to at least a 60° angle on a tilt table (Freeman et al. 2011)
what ,ay cause orthostatic hypotension?
Postural hypotension may be idiopathic or may arise as a result of disorders affecting the autonomic nervous system (for example, Parkinson’s disease, multiple system atrophy or diabetic autonomic neuropathy), from a loss of blood volume or dehydration, or because of certain medications such as antihypertensives
prevalence of orthostatic hypoension
Postural hypotension is more common in older people, and estimates of prevalence range from 5% to 30% of people aged over 65 years (in the general population), up to 60% of people with Parkinson’s disease, and up to 70% of people living in nursing homes (Freeman et al. 2011; Lahrmann et al. 2011). It is estimated that about 0.2% of people over 75 years are admitted to hospital with problems relating to postural hypotension
are any drugs licensed for orthostatic hypotension? [2]
There are no drugs with marketing authorisation for use in postural hypotension in the UK. Many drugs have been considered or studied for potential use in postural hypotension, including drugs that target the autonomic nervous system (such as midodrine, phenylephrine, ephedrine, pseudoephedrine, droxidopa and phenylpropanolamine), pyridostigmine, domperidone, non-steroidal anti-inflammatory drugs and erythropoietin
SE related to midodrine therapy
The most common adverse effects related to midodrine therapy (occurring in more than 1 in 10 people) are piloerection, pruritus of the scalp and dysuria, which lead to discontinuation of treatment in some people. Patients should be monitored for supine hypertension, which occurs in between 1 in 10 and 1 in 100 people. Reducing the dose of midodrine may resolve supine hypertension but, if it does not, treatment must be stopped. See the summary of product characteristics for more information
causes of an oxygen requirement post-op
- chest infection
- virus
3.PE - positional
- CCF
- ECOPD
- asthma
Mx of positional desaturation
sit patient up!
difference between dialysis and haemofiltration
indications for emergency dialysis
- severe hyperkalaemia [potiassium over 7]
- pulmonary oedema refractory to medical therapy
- worsening severe metabolic acidosis [pH below 7.2, or base excess below 10]
Mx of rhabdomyolsis
- aggressive fluid resuscitation aiming for U/O over 300ml per hour
- alkinisation with sodium bicarbonate if 1 does not work
urine output expected per person per day
- around 25-30ml/h/kg
Dx of rhabdomyolosis
CK over 1,0000 or 10 times persons normal limit
what is a nerve block and when is it used for NOF
Fascia iliaca block or femoral nerve block is used frequently in hip fracture patients because of their opioid-sparing effects and reduction in opioid-related adverse effects
