Fluid and electrolyte balance insurgical patients

Body fluids and electrolytes are distributed within different compartments.
Body fluid compartments
- In the human body fluid is distributed within the Extra Cellular (ECF) and Intra Cellular (ICF)
compartments.
- 60% of Total Body Weight = Total Body Water (TBW)
- 2/3 of TBW in ICF
- Remaining 1/3 in ECF
- ECF is distributed within the interstitial fluid and plasma compartments.
- Therefore, in a 70Kg man
TBW = 42 L (60% of 70Kg)
ICF = 28L (2/3 of 42L)
ECF = 14L (1/3 of 42L)
Interstitial Fluid (Extravascular volume) = 9-11L
Plasma (Intravascular volume)= 2-3L
- At any given time majority of the total body water is present in the ICF.
- Effective circulating volume
(Intravascular volume) = Total volume of blood (blood cells + plasma) in the circulation at any given time which is approximately 5L
Distribution of electrolytes within body fluid compartments
- Sodium is the predominant electrolyte in ECF
- Potassium is the predominant electrolyte in ICF
Distribution of volumes of various different types of intravenous fluids within the different compartments 1 hour after infusion
- Crystalloid (Hartmann's, Ringer Lactate, Normal Saline solution): Almost all (100%) will remian in the intravascular space upto 1 hr after infusion
Suitable for resucitation: sepsis, trauma
- Colloid (Albumin, Gelofusin,Starches, Haemaccel):
Intravascular: 25% - 30% (approximately a quarter to a third) remains in the intravascular space 1
hr after infusion.
Extravascular: 75% - 80% (approximately three quarters to two thirds) will be in the extravascular
space 1 hr after infusion.
Suitable for resucitation: trauma, sepsis
- 5% Dextrose solution:
Intravascular: < 10% will be in intravascular space 1 hr after infusion
Extravascular: 25% will be in the extrvascular space 1 hr after infusion
Intracellular: majority of the fluid will be absorbed in to the cells. Therefor NOT suitable for resucitation
Normal urine output:
0.5ml/kg/hr (adult)
1ml/Kg/hr (child)
Useful tool for approximation of hourly maintainance fluid requirement based on weight

THE 421 RULE - Estimates maintainance fluid requirement for an adult per hour
- 1st 10Kg, 4ml/hr
- 2nd 10Kg, 2ml/hr
- For each remaining Kg of weight, 1ml hr
Example: Therefore for a 70Kg patient:
- 1st 10Kg, 4ml/hr: 10 x 4 = 40ml/hr
- 2nd 10Kg, 2ml/hr: 10 x 2 = 20ml/hr
- Remainder 1ml/hr: (70-20) x 1 = 50ml/hr
Hourly maintainance fluid requirement: 40+20+50 = 110ml/hr (will need adlusting based on
increased losses etc)

THE 100,50,20 - Estimates maintainance fluid requirement for an adult over 24 hours
- 1st 10Kg, 100ml/Kg
- 2nd 10Kg, 50ml/Kg
- For each remaining Kg of weight, 20ml/Kg
Example: Therefore for a 70Kg patient (over 24hrs):
- 1st 10Kg, 100ml/Kg: 100 x 10 = 1000ml
- 2nd 10Kg, 50ml/Kg: 10 x 50 = 500ml
- Remainder 20ml/Kg: (70-20) x 1 = 1000ml
24 hour maintainance fluid requirement: 1000+500+1000 = 2500ml
(will need adlusting based on increased losses etc)
Therefore hourly fluid requirement = 2500/24 = 104ml/hr
Daily electrolyte requirement
- Na: 140mmol/day
- K: 60-80mmol/day
(Requirements may be considerably higher in ill, post op patients, e.g. severe vomiting, fluxing stoma etc)
Composition of common fluids
- Normal saline (0.9%) solution (1L):
Na - 154mmol
Cl - 154mmol
K - 0 mmol
- 5% Dextrose solution solution (1L): 50g of Dextrose
- Hartmann's (Ringer Lactate) (1L):
Na - 131mmol
Cl - 112mmol
K - 5mmol
Lactate - 29mmol (metabolised to
form HCO3 in the liver)
Trace Mg (1mmol) and Calcium
(1mmol)

Pancreatic Pseudocyst

PANCREATIC PSEUDOCYST

No epithelial lining hence pseudocyst
Most common site- Lesser sac
Most common part of pancreas involved- Body
Most common complication- Hemorrhage>Infection
Most common cause in children- Trauma
Most common cause in adults- Pancreatitis
Most common symptom in prodormal phase- Pain
IOC – CT scan
Acute pseudocysts are irregular,Chronic pseudocysts are circular
CEA levels- Low in pseudocysts,High in tumors

Cerebellar Nucleus

Four masses of gray matter are embedded in the white matter of the cerebellum on each side of the midline.

From lateral to medial, these nuclei are the
 dentate,
emboliform,
 globose, and
 fastigial dentate nucleus.
Mnemonic : " D on't Eat T oo G reasy Food " (lateral to medial). ‘ Too’ denotes the presence of two globose nuclei on each side.

Psuedo

Psuedohemoptysis: Serratia marcesans

Pseudoparalysis: Vit. C def

Pseudofracture: Osteomalacia

Pseudodementia: depression

Pseudolymphoma:  Sjogren syndrome

Pseudocommunity: Paranoid states

Pseudotabes: Diabetic foot

Pseudocoxalgia: Perthes disease

Hypertension

JNC 8 GUIDELINES - RECOMMENDATIONS FOR MANAGEMENT OF HYPERTENSION
Recommendation 1
In the general population aged ≥60 years, initiate pharmacologic treatment to lower blood pressure (BP) at systolic blood pressure (SBP) ≥150 mm Hg or diastolic blood pressure (DBP) ≥90 mm Hg and treat to a goal SBP <150 mm Hg and goal DBP <90 mm Hg.
(Strong Recommendation – Grade A)
Corollary Recommendation
In the general population aged ≥60 years, if pharmacologic treatment for high BP results in lower achieved SBP (eg, <140 mm Hg) and treatment is well tolerated and without adverse effects on health or quality of life, treatment does not need to be adjusted. (Expert Opinion – Grade E)

Recommendation 2
In the general population <60 years, initiate pharmacologic treatment to lower BP at DBP ≥90 mm Hg and treat to a goal DBP <90 mm Hg. (For ages 30-59 years, Strong Recommendation – Grade A; For ages 18-29 years, Expert Opinion – Grade E) 

Recommendation 3
In the general population <60 years, initiate pharmacologic treatment to lower BP at SBP ≥140 mm Hg and treat to a goal SBP <140 mm Hg. (Expert Opinion – Grade E) 

Recommendation 4
In the population aged ≥18 years with chronic kidney disease (CKD), initiate pharmacologic treatment to lower BP at SBP ≥140 mm Hg or DBP ≥90 mm Hg and treat to goal SBP <140 mm Hg and goal DBP <90 mm Hg. (Expert Opinion – Grade E) 

Recommendation 5
In the population aged ≥18 years with diabetes, initiate pharmacologic treatment to lower BP at SBP ≥140 mm Hg or DBP ≥90 mm Hg and treat to a goal SBP <140 mm Hg and goal DBP <90 mm Hg. (Expert Opinion – Grade E) 

Recommendation 6
In the general nonblack population, including those with diabetes, initial antihypertensive
treatment should include a thiazide-type diuretic, calcium channel blocker (CCB), angiotensin-converting enzyme inhibitor (ACEI), or angiotensin receptor blocker (ARB).
(Moderate Recommendation – Grade B) 

Recommendation 7
In the general black population, including those with diabetes, initial antihypertensive treatment should include a thiazide-type diuretic or CCB. (For general black population:
Moderate Recommendation – Grade B; for black patients with diabetes: Weak Recommendation – Grade C) 

Recommendation 8
In the population aged ≥18 years with CKD, initial (or add-on) antihypertensive treatment should include an ACEI or ARB to improve kidney outcomes. This applies to all CKD patients with hypertension regardless of race or diabetes status. (Moderate Recommendation – Grade B) 

Recommendation 9
The main objective of hypertension treatment is to attain and maintain goal BP. If goal BP is not reached within a month of treatment, increase the dose of the initial drug or add a second drug from one of the classes in recommendation 6 (thiazide-type diuretic, CCB, ACEI, or ARB). The clinician should continue to assess BP and adjust the treatment regimen until goal BP is reached. If goal BP cannot be reached with 2 drugs, add and titrate a third drug from the list provided.
Do not use an ACEI and an ARB together in the same patient. If goal BP cannot be reached using only the drugs in recommendation 6 because of a contraindication or the need to use more than 3 drugs to reach goal BP, antihypertensive drugs from other classes can be used. Referral to a hypertension specialist may be indicated for patients in whom goal BP cannot be attained using the above strategy or for the management of complicated patients for whom additional clinical consultation is needed. (Expert Opinion – Grade E)

HIV

HIV/AIDS :
MC organ system involvement as complication : Pulmonary
MC Opportunistic infection is Pneumonia.
MC cause of Pneumonia Is Pneumocystis Jiroveci.
Mc bacterial cause of Pneumonia : Pneumococcus> H.infuenzae
MC CVS manifestation is Coronary artery disease
MC CNS manifestation is HIV encephalopathy
MC Cause of blindness is CMV Retinitis
MC Malignancy is Kaposi Sarcoma
MC malignancy : SINGLE malignancy(asked once in exam) is Kaposi sarcoma
MC malignancy as a group(or in general, if not otherwise specified ) is Lymphoma
MC Sinusitis is that of Maxillary sinus.
MC Skin Infection is Seborrheic dermatitis> Folliculitis
MC Viral infection assc.with HIV is HSV-1
MC in iv drug abusers with HIV is HCV
MC cause of diarrhea is Cryptosporidium
MC fungal infection is Candida
MC cause of meningitis is Cryptococcus
MC spread by percutaneous route/ needle pricks : HBV>HCV
MC spread by blood transfusion : HCV
MC cause of Pulmonary involement in INDIA(if asked specifically) is TB.
Overall MC opportunistic infection is TB.... it affects virtually all major organ systems.
    It is also MC cause of pulm inv in INDIA;
    however, overall MC pulm inv is PCP. REf : Harrison 18th as well as NACO status paper

MC fungal infection in febrile neutropenia is Candida> aspergillus
Mc fungal infection overall, world & India : Candida albicans;
     same in Immunocompetent and immcompromised
MC cause of Systemic fungal infection in HIV is Cryptococcus.

HIGH YIELD POINTS ON MENINGITIS :
*Neonates :
India : E.coli and other gram neg> Group b Strep> Listeria
In world, it is Group B strep*2months to 2 yr is H.infuenzae
> 2 yr
it is Pneumococcus> Neisseria mening.
*Overall MC cause of menin in all age groups is Pneumococcus
*MC associated with sequelae is H.infuenzae
*Mc assc wid Sensorinueral hearing loss and Subdural effusion in meningitis : H.influenza
*Empirical treatment of choice in neonatal meningitis : Cefotaxime + Amikacin*Antibiotics
Contraindicated in meningitis : Ciprofloxacin (does not cross infamed meninges), Imipenem( Causes seizures)
*DOC for penicillin allergy in meningitis is Chloramphenicol Ref Nelson
*Duration of therapy in meningitis is 21 days
*In US, due to routine H.influenza vaccination since last 20 yrs, it is no longer a common cause.
however, in INdia as well as in whole world, it is still MC cause in 2 mth to 2 yr age group
*steroids in meningitis-
Nelson 18th ed says regarding use of steroids in meningitis:"Data support the use of intravenous dexamethasone,
0.15 mg/kg/dose given every 6 hr for 2 days,in the treatment of children older than 6 wk with
acute bacterial meningitis caused by H. influenzae type b.
However, data are inconclusive regarding the benefit, if any, of corticosteroids in the treatment
of meningitis caused by other bacteria. Therefore, their use is controversial.
Among children with meningitis due H. influenzae type b, corticosteroid recipients had less fever,
lower CSF protein and lactate levels, and a reduction in permanent auditory nerve damage,
as manifested by sensorineural hearing loss, than did placebo recipients, enrolled in randomized,
controlled trials. Corticosteroids appear to have maximum benefit if given 1-2 hr before antibiotics were
initiated. Corticosteroids are not harmless; complications of their use may include gastrointestinal bleeding,
hypertension, hyperglycemia, leukocytosis, and rebound fever, after the last dose.
"*Clinically, steroids are used in meningitis in only TB meningitis & H.influenzae
*Steroids are used in TB meningitis in both established hydrocephalus,
as well as to decrease chances ofdeveloping hydrocephalus(although this point is a controversial one )!

**For NEONATAL SEPSIS the sequence is Klebsiella>E.coli>Group B strep>Staph aureus REF : AIIMS WHO 2010 Protocols
*same organisms for early and late onset
*In young adults, yes Neisseria but questions specifically ask either about children or adults.
In adults it is Pneumococcus..
if they ask young adults/adolescents, it is Neisseria..

Numericals

vol. of eye ball--6.5ml
wt of eye ball--6.8 gms
vol of orbit--30ml
A.P  diameter --24mm
doctor-1/3500
health worker--1/5000
trained dai--1/1000
ASHA-1/1000
village health guide--1/1000
pharmacist n lab technician---1/10000
classroom--1/40student
furniture --minus desk
doors& windows---25%floor area
urinal--1/60studen
latrine--1/100studen
beds in PHC --4-6/30000
CHC--30/LAKH