❗️SEEING SIADH👁

✍Clinical euvolemia, hypotonic plasma, and less than maximally dilute urine are the clues 

✍establish normovolemia by physical examination. 

(Patients with SIADH are usually said to have normal volume status. However, they actually have excessive TBW. Unlike excessive saline, which is limited to ECF, excessive water distributes two thirds to the ICF and one third to the ECF. Thus the ECF excess is minor and not usually perceptible by clinical examination. Nonetheless, patients with SIADH have mildly increased ECV, which is sensed by the kidney. The kidney increases GFR, which causes a low uric acid, BUN, and creatinine. The increased ECV also increases ANP and, along with increased GFR, promotes natriuresis.)

✍measure P osm ,U osm ,P Na ,U Na , and U K . 

✍exclude pituitary, adrenal, and thyroid dysfunction 

✍Confirmatory criteria of SIADH include low P Na ( < 135 mEq/L), low P osm ( < 280mOsm/kg), U osm greater than 100mOsm/kg, U Na greater than 40mEq/L, and [U Na + U K ] greater than P Na . 

#SIADH , #anesthesia

D for DANTROLENE🔅

✔️Dantrolene inhibits calcium release via RyR1 antagonism and impairs calcium-dependent muscle contraction. 

✔️This rapidly halts the increases in metabolism and secondarily results in a return to normal levels of catecholamines and potassium. 

✔️Dose is 2 mg/kg; repeat every 5 minutes until vital signs normalise , to a total dosage of 10 mg/kg if needed. 

✔️dantrolene takes ~ 6 minutes to have any effect

✔️The solution is prepared by mixing 20 mg of dantrolene with 3 g of mannitol in 60 ml of sterile water. 

✔️Since dantrolene is relatively insoluble, preparation is tedious and time consuming, and its preparation should not be the responsibility of the primary anesthesiologist involved in the patient’s management. (May occupy several nurses)

✔️All patients who develop MH, require at least 24 hours of posttreatment management in a critical-care setting as there is chance of reappearance of symptoms ( known as recrudescence )

🔸In the ICU, continue @1mg/kg q6h for 24 hours 

🔸may be given enterally if GIT functioning  (price ~ 1000 x  less)

✔️the actions of dantrolene include:

🔸 release  of Ca ++  from the SR, without affecting re-uptake

🔸 ? antagonises the effects of Ca ++  at the actin/myosin - troponin/tropomyosin level 

🔸muscular weakness, which may potentiate NMJ blockade ~ 5-15 mg/kg produces significant muscular relaxation 

🔸there is no  effect on NMJ transmission 

🔸up to 15 mg/kg there is no  significant effect on the CVS 

🔸up to 30 mg/kg there is no  significant effect on respiration

#dantrolene , #MalignantHyperthermia, #mh ,#anaesthesia

THE RIGHT WAY OF ADMINISTERING BLOOD PRODUCTS 💧💧💧💧💧 [ from "THE CLINICAL USE OF BLOOD: HAND BOOK , World Health Organization & Blood Transfusion Safety , GENEVA ]

✔️Prefer a larger cannula: A doubling of the diameter of the cannula increases the flow rate of most fluids by a factor of 16. 

✔️In case of Whole blood, red cells, plasma and cryoprecipitate 


>Use a new, sterile blood administration set containing an integral 170–200 micron filter 

>Change the set at least 12-hourly during blood component infusion 


>In a very warm climate, change the set more frequently and usually after every four units of blood, if given within a 12-hour period 

✔In case of Platelet concentrates 

>Use a fresh blood administration set or platelet transfusion set, primed with saline. 

✔️WARMING BLOOD:

>There is no evidence that warming blood is beneficial to the patient when infusion is slow. 

>At infusion rates greater than 100 ml/minute, cold blood may be a contributing factor in cardiac arrest. However, keeping the patient warm is probably more important than warming the infused blood. 

>Warmed blood is most commonly required in: 


[1]Large volume rapid transfusions: 

    -Adults: greater than 50 ml/kg/hour 
     -Children: greater than 15 ml/kg/hour 

[2]Exchange transfusion in infants 
 

[3]Patients with clinically significant cold agglutinins. 

>Blood SHOULD ONLY BE WARMED in a blood warmer. Blood warmers should have a visible thermometer and an audible warning alarm and should be properly maintained. 

>Blood should never be warmed in a bowl of hot water as this could lead to haemolysis of the red cells which could be life-threatening. 

✔️Severe reactions most commonly present during the first 15 minutes of a transfusion. All patients and, in particular, unconscious patients should be monitored during this period and for the first 15 minutes of each subsequent unit. 

✔️The transfusion of each unit of the blood or blood component should be completed within four hours of the pack being punctured. If a unit is not completed within four hours, discontinue its use and dispose of the remainder through the clinical waste system. 



















DESMOPRESSIN

ADMINISTRATION  ROUTES: IV,  IM,  SC,  Intranasal DDAVP/Desmopressin

INDICATIONS: 

1. Treatment  of  central  diabetes  insipidus 2. Prevention  and  control  of  bleeding  (primarily  when  there  are  thought  to  be platelet  function  defects  especially  uraemia,  clopidogrel  or  cardiopulmonary bypass  -related)

 PRESENTATION AND ADMINISTRATION: 

IV: Minirin  4mcg/ml  injection Octostim  15mcg/ml  injection Doses  of  4mcg  or  less  should  be  administered  undiluted  by  direct  IV  injection.    For small  doses  (eg  0.4mcg),  4mcg  can  be  diluted  in  10  ml  of  normal  saline. For  doses  of  greater  than  4mcg  in  adults  or  children  weighing  more  than  10kg,  dilute with  50ml  of  normal  saline  and  infuse  the  first  5ml  slowly  over  5  minutes.    For  children weighing  less  than  10kg,  dilute  in  10ml  of  normal  saline  and  infuse  the  first  1-2ml  over  5 minutes.    If  no  marked  tachycardia  or  other  adverse  effects  are  observed,  give  the remainder  slowly  over  15  minutes PO: Minirin  0.1mg  tablets  (white)

 Nasal  Spray: Desmopressin  spray  (10mcg/dose),  Minirin  spray  (10mcg/dose),  Octostim  (150mcg/ dose) 

DOSAGE: 

IV: Central  diabetes  insipidus: 0.4mcg  repeated  as  required  (may  increase  the  dose  if  there  is  an  adequate  response)

 Prevention  and  control  of  bleeding: 0.3mcg/kg  (max  24mcg)  over  30  minutes  (once  only) Note:  although  IM  and  SC  routes  can  be  used,  IV  is  generally  the  preferred  route. PO: 0.1mg  -1.2mg  daily  depending  on  indication  (rarely  used  by  this  route  in  ICU)

 Nasal  Spray: Not  generally  administered  by  this  route  in  ICU

No adjustments needed in CRF

CLINICAL  PHARMACOLOGY: Desmopressin  is  a  synthetic  analogue  of  the  natural  pituitary  hormone  arginine vasopressin  (ADH),  an  antidiuretic  hormone  affecting  renal  water  conservation..

 CONTRAINDICATIONS: 

1. Hypersensitivity  to  desmopressin 2. Hyponatraemia

 WARNINGS 

When  desmopressin  acetate  injection  is  administered  to  patients  who  do  not  have  need of  antidiuretic  hormone  for  its  antidiuretic  effect,  in  particular  in  paediatric  and  geriatric patients,  fluid  intake  should  be  adjusted  downward  to  decrease  the  potential  occurrence of  water  intoxication  and  hyponatraemia.

 Particular  attention  should  be  paid  to  the  possibility  of  the  rare  occurrence  of  an  extreme decrease  in  plasma  osmolality  that  may  result  in  seizures  which  could  lead  to  coma. 

Laboratory  Tests:

 Laboratory  tests  for  monitoring  the  patient  include  urine  volume  and  osmolality.  In  some cases,  plasma  osmolality  may  be  required.

NB: may  cause  minor  increases  in  blood  pressure  requiring  changes  in  levels  of vasopressor  support. 

ADVERSE  REACTIONS 

 transient  headache,  ischaemic  stroke,  changes  in  blood  pressure  causing  either  a  slight  elevation  or  a  transient  fall  and  a compensatory  increase  in  heart  rate,  myocardial  infarction, nausea, abdominal cramps, water  intoxication  and  hyponatraemia,Local  irritation  at  site  of  injection,  thrombotic  events

LAPAROSCOPIC MYOMECTOMY; INSIGHTS FOR THE ANESTHESIOLOGIST

# Preoperative treatment with GnRH analogue to shrink the fibroid

# Surgeon may intraoperatively inject dilute Vasopressin ( 1 IU in 100 mL RL) to reduce bleeding. IV Vasopressin can cause raised BP, myocardial ischemia, arrhythmias etc

# Position: Dorsal lithotomy; steep Trendlenberg to move the bowel out of surgical field

# Surgical time :1-4 hours; EBL: 100-600 mL

# Complications: 

Puncture of major vessel/ severe bleeding 

Insufflation in the wrong place

Air Embolism

Need for conversion to laparotomy

Peroneal nerve damage from positioning

# Pain score : 4-6

#laparoscopy,#laparoscopyanaesthesia,#myomectomy, #anaesthesia, #anaesthetist

ANAESTHETIC MANAGEMENT OF SURGICAL PROCEDURES UNDER ECMO

The plastic components of the bypass circuit can sequester varying amounts of intravenous anesthetic agents resulting in unpredictable effects and side effects 

Volatile anaesthetics are not usually available on ECMO circuits due to the difficulties in scavenging 

Since anesthetic agents can alter preload and afterload, should be ready for volume replacement and administration of vasoactive agents

Should inform the perfusionist before changing the height of the surgical table, as this can alter the venous return to the ECMO circuit ( passive gravity assisted drainage)