💂ATRIAL NATRIURETIC FACTOR💂

💧26 AA peptide hormone 

💧synthesised from a prohormone in atrial secretory granules released in response to atrial stretch /  wall tension 

💧plasma half life, t ½ β  ~ 3 mins 

💧maximal natriuresis is less than that seen with frusemide

💧however ANF is ~ 100 times as potent 

💧receptors are concentrated in cortical  glomeruli 

💧the postulated second messenger is cGMP ? 

💧there is no direct effect upon Na +  transport, or the Na + /K +-ATPase 

💧neither amiloride nor prostaglandin inhibitors have an effect upon its actions 

💧ANF effects include

🎯systemic vasodilatation ( mostly venodilation--> transient hypotension, decreases preload

🎯increases salt delivery to distal tubule

🎯decreases plasma renin 

🎯decreases plasma aldosterone 

🎯increases urinary excretion of Na, K, Ca, Mg, Phosphate, Chloride

🎯increases urine volume

EPILEPSY SURGERY- VARIANT APPROACHES🙇🙇🏻🙇🏼🙇🏾: CORPUS CALLOSOTOMY

✔️Suited for patients with atonic or partial seizures with secondary generalisation 

✔️Either the anterior 2/3rd or the entire corpus callosum is divided in the midline

✔️Uses a bifrontal paramedian scalp incision and elevation of the free bone flap, adjacent to the midline in the region of the coronal suture

✔️Injury to the sagittal sinus can result in massive VAE or haemorrhage 

✔️Preserve the numerous bridging veins across the interhemispheric fissure; otherwise, can result in venous congestion and possible infarction 

✔️Right cerebral hemisphere is gently retracted from the falx: this will expose the paired anterior cerebral arteries and corpus callosum

#epilepsy , #seizures ,#neurosurgery , #EpilepsySurgery , #NeuroAnaesthesia ,#NeuroAnesthesia , #speech ,#wadatest

EPILEPSY SURGERY: SPECIFIC PROCEDURES & HIGHLIGHTS : TEMPORAL LOBECTOMY

✔️ Head turned 90* and held with pins

✔️ Most commonly a "question mark" temporal incision

✔️ a flap based on temporalis muscle elevated

✔️ a subtemporal craniectomy allows visualisation of entire anterior temporal lobe

✔️ anterior 6-6.5 cms of temporal lobe exposed

✔️ surface or depth electrocorticography employed

✔️ map the lesion

✔️ amygdala, hippocampus/ anterior temporal lobe removed 

✔️ Temporal lobectomy involves resection of both lateral and medial (uncus, hippocampal formation etc) temporal structures, mostly under an operating microscope

✔️ Complications: Injury to brainstem, 3rd and 4th cranial nerves , Middle or Posterior Cerebral arteries

✔️ closure of dura, bone flap and scalp concludes the surgery

#epilepsy , #seizures ,#neurosurgery , #EpilepsySurgery , #NeuroAnaesthesia ,#NeuroAnesthesia , #speech ,#wadatest

☁️EPILEPSY SURGERY: BASIC FACTS

☄Most beneficial in partial seizures secondary to a structural lesion

☄For determining the cerebral dominance and hence the location of speech , a WADA test (intracarotid injection of anesthetic to localize language function ; hence invasive) or recently functional MRI mapping (non invasive) of speech centres are done preoperatively 

☄Simultaneous recordings of video EEG and MRI or PET scans can show the epileptogenic focus

☄Temporal lobe surgery may involve:

✔️removal of only the structural lesion & associated epileptogenic cortex

✔️cortical resection alone

✔️excision of amygdala and hippocampus 

✔️removal of the entire anterior temporal lobe (extent of posterior resection dependent on dominance)

✔️depending on the local protocol, intraoperative Electro Corticogram (ECoG) may be used; anesthesia has to be modified accordingly

✔️if speech centre has to be located intraoperatively, an awake craniotomy is required

✔️ So depending on the surgical plan, choice of anesthesia varies

ADVERSE EFFECTS OF UNDER TREATED SEVERE ACUTE PAIN

(Reference: Pamela E. Macintyre,Stephan A. Schug. ACUTE PAIN MANAGEMENT; A PRACTICAL GUIDE)

👹Tachycardia, hypertension

👹increased myocardial oxygen consumption, myocardial ischemia

👹 Decreased lung volumes, atelectasis, decreased cough, sputum retention, infection, hypoxemia

👹Decreased gastric and bowel motility 

👹Urinary retention 

👹Increased catabolic hormones: glucagon, growth hormone, vasopressin, aldosterone, renin, and angiotensin 

👹Reduced anabolic hormones: insulin, testosterone 

👹Catabolism leads to hyperglycemia, increased protein breakdown and negative nitrogen balance; ➡️impaired wound healing and muscle wasting 

👹 Muscle spasm, immobility (increasing risk of deep-vein thrombosis-->pulmonary embolism) and muscle wasting 

👹 Chronic (persistent) pain due to central sensitization 

👹 Anxiety, fear, helplessness, sleep deprivation—leading to increased pain and potential long-term psychological effects