Post-Op Care Fluids (CMPP)

Treatment for Malignant Hyperthermia

IV Dantrolene

Indications for IV Access

Deliver fluids

Deliver medications

Draw blood

Monitor body systems

Why are post-op patients often hypovolemic?

NPO prior to surgery

NPO post-surgery inhibition of GI tract

Blood loss due to surgery or trauma

Third spacing in surgery

who manages fluids in the OR

anesthesiologist or CRNA

Who manages post-op fluids

surgical team

4/2/1 Rule

A method of calculating the volume for maintance fluids for post-op

• 4 cc / kg / hr for first 10 kg

• 2 cc / kg/ hr for next 10 kg

• 1 cc / kg / hr for evert kg above 20kg

If a patient needs more post-op fluids than maintence fluods

Fluid boluses

Who may not need post-op fluids

CHF

hemodialysis

What patients may need replacement of losses with post-op

nasogastric tube

ostomy outputs

If patients can eat and drink, how do adjust maintained fluids

continue fluids at half-rate until the patient has demonstrated that he or she can keep adequately hydrated

How often are vitals done in the PACU

every 15 to 30 minutes until the patient has recovered from anesthesia and can be transferred to their room

How often are vitals done in the post-op patient

vitals every 4 hours at minimum (

best indicator of adequate volume replacement

urine output

How much fluid is loss due to insensible fluid loss

10 cc / kg / day

What are the sources of insensible fluid loss

Sweat #1

Respiratory

What can increase insensible fluid loss

Fever,

burns,

large open wounds,

ventilated patients

Average adult input/output

30-35mL/kg/day (2.4L/day)

Minimal Obligatory Daily Water input

Ingested water: 500mL

Water content in food: 800mL

Water from oxidation: 300mL

TOTAL: 1600mL

Minimal Obligatory Daily water output:

Urine: 500mL

Skin: 500mL

Respiratory tract: 400mL

Stool: 200mL

TOTAL: 1600mL

How are IVFs done after major GI surgery

the first 24 hours, use LR

After 24 hours, switch to D5 ½ NS with 20 mEq K+

Why is D5 a part of maintence

stimulate insulin release

prevent protein breakdown (prevents protein catabolism)

At 125 cc/hr, how much glucose is given from D5

150g glucose / 525 kcal

What is the fluid loss for open abdominal

0.5 to 1.0 L/h unless there are measurable blood losses

When does blood need to be replaced during open abdomen surgery

greater than 500 cc

What IVFs are isotonic

0.9% Sodium (Normal Saline [NSS])

Ringer’s solution

Lactated Ringer’s solution

5% Dextrose in 0.225% saline (D5 ¼ NSS)

What IVFs are hypertonic

10% Dextrose in Water (D10W)

3% Saline

5% Dextrose in 0.45% saline (D5 ½ NSS)

5% Dextrose in 0.9% saline (D5 NSS)

What IVFs are hypotonic

0.45% Saline (1/2 NSS)

5% Dextrose in Water (D5W)

Daily Na requirements

100-250 mEq

How is Na excreted

mainly urine

Daily K requirements

50-100meq

How is K excreted

mainly urine

5% feces

Daily Cl requirements

60-150meq

why NS should not be used for maintenance fluid in patients with normal renal function

risk of hyperchloremic metabolic acidosis

Daily HCO3 requirements

1 meq/kg/day

What are the body Fluid Compartments

Intracellular compartment 60-65%

Extracellular and Intravascular 35-40%

What compartment in the body is the “first space”

Intravascular compartment

What compartment in the body is the “second space”

Intracellular

What compartment in the body is the “third space”

here fluid does not usually go, but may accumulate

What are the two main barriers between intravascular and intracellular

Blood-brain barrier

Blood-bone barrier

How can fluids shift in major trauma and surgery

), inflammation and reaction can cause extensive third spacing, where fluids and electrolytes (and any drugs in system) are not bioavailable

Purpose of maintenance therapy

Replace ongoing losses of water and electrolytes under normal physiological conditions

In an afebrile, non-active, not eating patient, how much free water is used daily

< 1 L

What are the approaches to maintenance fluids

Average requirement (i.e. 35 cc/kg/day)

4/2/1 rule

Weight in kg + 40 = cc / hr

What is the norma; maintained fluid

D51/2NS + 20 mEq KCl

When should we avoid D5 in maintenance fluids

Uncontrolled DM

Hypokalemia

If a patient on maintenance fluids develops hyponatremia, what can be done

Change from ½ NS to NS

Purpose of Fluid Resuscitation

: Correct existing abnormalities in volume status or serum electrolytes

What are the parameters used to assess volume deficit

Blood pressure

Jugular venous pressure

Urine sodium concentration

Urine output

Pre and post-deficit body weight

What fluids are given for severe volume depletion / hypovolemic shock

Rapid infusion of 1-2L isotonic saline (NS), then reassess parameters

Use Lactated Ringers if concern for re-expansion acidosis

What fluids are give for mild-moderate hypovolemia

Estimate fluid losses:

Choose rate 50-100mL/h greater than estimated losses

Select fluid based on type of fluid that has been lost and any co-existing electrolyte disorders

How do we estimate fluid loss for fluid resusciation

Average output (30-35mL/kg/day) + estimated additional losses

How do we estimate loss of fluid for high fevers

Add 100mL / day of loss for each degree above 37 C

Treatment for Volume Overload

Fluid restriction

Diuretics

How can volume overload occur with IVFs

too vigorous resuscitation

mobilization of third-space fluids

What is the routine post-op replacement for general abdominal surgery

Total loss → 3500 mL

• Third spacing = 1000 ml

• Urine = 1000 ml

• NG tube = 1000 ml

• Insensible = 500 ml

Loss per hour = 146 mL/hr

Add maintenance (104)

Run at 250 mL/hr

Losses in NG tubes tend to be

High in Cl

“Hep lock”

an IV catheter left in without running fluid to maintain access in an emergency or for intermittent access

“KVO”

run minimal amount of fluid, only enough to keep IV from clotting off