Monday, February 20, 2012

TOW the trials

Magpie:
multicentre RCT 10000 women
mag sulph vs placebo
primary outcomes: eclampsia and death of baby
result: 58% lower risk of eclampsia, lower maternal mortality, no diff in baby mortality

TRACman
tracheostomy : early vs late
multicentre prospective RCT
early 1-4, late not before day 10
primary outcome : 30day mortality

CESAR trial:
conventional ventilatory support vs ECMO in severe adult respi failure
mortality and disability lower in ECMO group , likely to be cost effective

VASST trial
vasopressin and septic shock:
low dose 0.01-0.03u/min or norad

NO in ARDS:
no sig diff in groups in mortality, duration, ventilator free days
no group: higher pao2/fio2 on day 1, but increased risk of renal dysfunciton

Saturday, February 11, 2012

CTG definitions

ean level of the FHR when this is stable, excluding accelerations and decelerations. It is determined over a time period of 5 or 10 minutes and expressed in bpm. Preterm fetuses tend to have values towards the upper end of this range. A trend to a progressive rise in the baseline is important as well as the absolute values

Normal Baseline FHR
110-160 bpm

Abnormal bradycardia
<100 bpm

Abnormal tachycardia
>180 bpm

Baseline variability
The minor fluctuations in baseline FHR occurring at three to five cycles per minute. It is measured by estimating the difference in beats per minute between the highest peak and lowest trough of fluctuation in a one-minute segment of the trace

Normal baseline variability
Greater or equal to 5 bpm between contractions

Non-reassuring baseline variability
Less than 5 bpm for 40 minutes or more but less than 90 minutes

Abnormal baseline variability
Less than 5 bpm for 90 minutes or more

Accelerations
Transient increases in FHR of 15 bpm or more and lasting 15 seconds or more. The significance of no accelerations on an otherwise normal CTG is unclear

Decelerations
Transient episodes of slowing of FHR below the baseline level of more than 15 bpm and lasting 15 seconds or more

Early decelerations
Uniform, repetitive, periodic slowing of FHR with onset early in the contraction and return to baseline at the end of the contraction

Late decelerations
Uniform, repetitive, periodic slowing of FHR with onset mid to end of the contraction and nadir more than 20 seconds after the peak of the contraction and ending after the contraction. In the presence of a non-accelerative trace with baseline variability < 5 bpm, the definition would include decelerations < 15 bpm

Variable decelerations
Variable, intermittent periodic slowing of FHR with rapid onset and recovery. Time relationships with contraction cycle are variable and they may occur in isolation. Sometimes they resemble other types of deceleration patterns in timing and shape

Atypical variable decelerations
Variable decelerations with any of the following additional components: i. loss of primary or secondary rise in baseline rate, ii. slow return to baseline FHR after the end of the contraction. iii. prolonged secondary rise in baseline rate, iv. biphasic deceleration, v. loss of variability during deceleration, vi. continuation of baseline rate at lower level.

Prolonged deceleration
An abrupt decrease in FHR to levels below the baseline that lasts at least 60-90 seconds. These decelerations become pathological if they cross two contractions, i.e. greater than 3 minutes

Sinusoidal pattern
a regular oscillation of the baseline long-term variability resembling a sine wave. This smooth, undulating pattern, lasting at least 10 minutes, has a relatively fixed

post op visual loss

0.01-1%
commonest causes
- ischaemic optic neuropathy (posterior more common; opthalmic artery branches, risk: hemorrhagic hypotension, not necc with extrinsic compression)
-central retinal arterial occlusion (retinal artery thrombosis: retinal pallor, cherry red spot)
(extrinsic compression)

commonest risk factors:
patient - closed angle glaucoma; male patient, diabetic, hypertension, atherosclerosis, smoking
surgery: prolonged, massive blood loss, anemia
anaesthesia: hypotension, extrinsic pressure on eye, increased CVP (resulting in increased IOP), prone position itself increase IOP (head dependent- worse; head up, better)

ameliorating: position 10' head up, careful no pressure on eye, higher transfusion trigger