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Paper text:
such changes are referred as part of autonomic dysreflexia ( ad ) or hyper reflexia .
it can even occur during surgery ; however , we present an interesting case where ad happened with non - flow of infusion saline in arterial circulation despite high infusion pressure .
a 45-year - old male presented with sudden onset headache and altered sensorium . on arrival , his glasgow coma score was e4m5v4 .
plain computed tomography of the head revealed blood in left sylvain cisterns suggestive of subarachnoid hemorrhage .
patient was taken up for endovascular coiling on first available operation theatre , i.e. , 3 days after admission under general anesthesia .
pressure cuff was applied on the infusion vac and a pressure of 250 mmhg was maintained on the pressure bag to allow easy flow of heparinised saline . a microcatheter ( prowler 14 )
while negotiating microcatheter , the bp shot up to 200/110 mmhg and pulse was 100/minute .
patient was , however , in deep anesthesia . at this stage of the procedure ,
the flow of saline solution stopped despite a pressure of 250 mmhg in infusion chamber .
there was reflux of blood via the 6-f catheter back into the irrigating arterial tubing despite a constant pressure of 250 mmhg on the fluid bags .
there was no evidence of intraoperative rupture of aneurysm during procedure . for about 20 minutes
the attempts to control the bp with diltizam ( 5 mg ) and propofol failed and bp remained on higher side ( 200/110 mmhg ) .
the reflux of blood back from femoral artery into the intra - arterial lines resulted in halting of the procedure . at this stage surgeon noticed grossly distended abdomen and suspected a full bladder .
the tubing was repositioned , which resulted in bladder empting and settling of bp and pulse .
most of the endovascular coiling are done under general anesthesia so that the patient does not move the head .
any shake in the body can impair the road map picture which forms the basic guide for the proper procedure .
the coiling also requires a meticulous control of pulse and bp in right plane of anesthesia .
the autonomic responses , e.g. , increase in bp and changes in pulse rate can be due to lighter plane of anesthesia , intraoperative rupture of aneurysm , some drug reaction , or thromboembolic episodes during surgery .
hypertension responses are elicited with somatic stimulation above the lesion , and the response may require aggressive pharmacologic management . beside full bladder , the other causes of ad are bladder infection , severe constipation , loaded colon , or pressure sores .
experimental results using the rat urinary bladder distension model demonstrated the role of the analgesics ( morphine , u50,488 , and mexiletine ) in the inhibition of visceral nociceptive transmission .
higher incidence of symptomatic ad is reported in subjects using reflex voiding and in those using manual removal of stool .
by contrast , the lowest incidence of symptomatic ad was in those on continent spontaneous voiding and continent spontaneous defecation .
the symptoms that occur with ad are directly related to the types of responses that happen in the sympathetic and parasympathetic nervous systems .
serotonergic and noradrenergic facilitation are also believed as mechanism of ad . during an episode of ad , a significant increase in visceral sympathetic activity with coronary artery constriction can result in myocardial ischemia , even in the absence of coronary artery disease .
the other suggests that glutamate transferase ( glt-1 ) overexpression attenuates the visceromotor response to bladder distension and both local irritant - induced and cross organ - sensitized visceromotor response to bladder distension due to overexpression of the astrocytic glutamate transporter ( glt-1 ) .
other observations support the concept that ganglionic acertyl choline resistant ( achr ) antibodies are diagnostically and pathophysiologically important .
patients with orthostatic hypotension and prominent cholinergic dysautonomia are most likely to be seropositive for ganglionic achr antibody .
the salient feature of autonomic changes in our case was its association with reflux of blood into the arterial lines .
association of reflux of blood back into arterial line under infusion pressure of 250 mmhg and autonomic changes were rather peculiar .
it is well known that the filled bladder can result in reflex increased in intra - aortic pressure . however , in our case the intra - arterial pressure was 200/110 mmhg which was about 50 mm less than the pressure in the infusion vac .
the pressure gradient across the infusion saline and bp was enough to allow the flow of the saline into the arterial line .
the hemodynamic changes , e.g. , increase in bp and tachycardia was due to ad .
the mechanism that led to reflux could be due to the direct pressure of distended bladder on the aorta or at femoro - aortic junction resulting in direct compression and king in angiocatheters [ figures 1 and 2 ] against bony vertebral body .
note the relationship of aorta and catheter within it and empty bladder schematic representation of filled , distended bladder causing mechanical compression on aorta and catheter against bony vertebral columns resulting in kink , v , vertebral body ; a , aorta ; c , angiocatheter ; b , urinary bladder
the autonomic changes due to filled bladder can result in increase in bp and tachycardia . to settle these changes ,
however , a careful clinical inspection of the status of urine bag can avoid the use of unnecessary medication , compressions on arterial system , and angiocatheter resulting in backflow of arterial blood into arterial lines .
autonomic dysreflexia due to distended bladder is well known . 
 reflux of blood during endovascular procedure is also a common observation . 
 it happens due to difference in pressure gradient between arterial pressure and that of infusing solution . 
 generally it happens when the infusion bottle is empty or the pressure in infusion bottles fall . 
 we present an uncommon situation where distended bladder mechanically resulted in reflux of blood into endovascular catheters as well as alteration in hemodynamic parameters . 
 both settled once the bladder was empty .