Basic Considerations - Response to Injury, Fluids, and Nutrition

What percentage of total body weight is typically composed of water?

~50-60%

Total body water (TBW) is primarily a reflection of what bodily component?

Body fat

Which tissue types have a higher water content than fat and bone?

Lean tissues (e.g., muscle and solid organs)

What is the total body water (TBW) percentage in an adult male?

60%

What is the total body water (TBW) percentage in an adult female, and why is it lower?

50%, due to higher adipose tissue and lower muscle mass

What is the total body water (TBW) percentage in newborns?

80%

Into how many functional fluid compartments is total body water (TBW) divided?

3 functional fluid compartments (Plasma, Interstitial fluid, Intracellular fluid)

In a normal 70 kg man, what percentage and volume of total body water is extracellular fluid (ECF)?

20% (14L)

In a normal 70 kg man, what percentage and volume of total body water is intracellular fluid (ICF)?

40% (28L)

In a normal 70 kg man, what percentage and volume does plasma make up within the extracellular fluid?

5% (3.5L)

In a normal 70 kg man, what percentage and volume does interstitial fluid (ISF) make up within the extracellular fluid?

15% (10.5L)

What are the major cations and anions of the Extracellular Fluid (ECF)?

Cations: Na+; Anions: Cl-, HCO3-

What are the major cations and anions of the Intracellular Fluid (ICF)?

Cations: K+, Mg2+; Anions: PO4-, proteins

What effect describes how a slightly higher protein content (anions) in plasma results in a higher plasma cation composition relative to ISF?

Gibbs-Donnan Effect

What is the total average daily fluid input in a normal individual?

2500 mL

What are the normal daily fluid input components and their standard volumes?

Oral fluids (1500 mL), Solid foods (750 mL), Insensible gain from water of oxidation (250 mL)

What is the total average daily fluid output in a normal individual?

2500 mL

What are the normal daily fluid output components and their standard volumes?

Urine (1500 mL), Insensible losses from skin and lungs (700 mL), Sweat (200 mL), Stool (100 mL)

Insensible fluid losses are divided between skin and lungs in what proportions?

Skin: 75%, Lungs: 25%

What additional surgical fluid losses must be accounted for during intake and output (I/O) calculations in surgery?

Bleeding and outputs from surgical drains (e.g., IP Drains, Penrose, NGT)

What is the sodium (Na+) concentration in Saliva?

10

What is the potassium (K+) concentration in Saliva?

26

What is the chloride (Cl-) concentration in Saliva?

10

What is the bicarbonate (HCO3-) concentration in Saliva?

30

What is the normal daily volume of Saliva?

1,000 mL

What is the osmolality of Saliva?

Variable

What is the sodium (Na+) concentration in stomach fluid?

60

What is the potassium (K+) concentration in stomach fluid?

10

What is the chloride (Cl-) concentration in stomach fluid?

130

What is the normal daily volume of gastric (stomach) secretions?

1,500 mL

What is the osmolality of stomach fluid?

280

What is the sodium (Na+) concentration in duodenal fluid?

140

What is the potassium (K+) concentration in duodenal fluid?

5

What is the chloride (Cl-) concentration in duodenal fluid?

80

What is the normal daily volume of duodenal secretions?

1,500 mL

What is the osmolality of duodenal fluid?

280

What is the sodium (Na+) concentration in ileal fluid?

140

What is the potassium (K+) concentration in ileal fluid?

5

What is the chloride (Cl-) concentration in ileal fluid?

104

What is the bicarbonate (HCO3-) concentration in ileal fluid?

30

What is the normal daily volume of ileal secretions?

3,000 mL

What is the osmolality of ileal fluid?

280

What is the sodium (Na+) concentration in colonic fluid?

60

What is the potassium (K+) concentration in colonic fluid?

35

What is the chloride (Cl-) concentration in colonic fluid?

40

What is the normal daily volume of colonic secretions/losses?

750 mL

What is the osmolality of colonic fluid?

280

What is the sodium (Na+) concentration in pancreatic fluid?

145

What is the potassium (K+) concentration in pancreatic fluid?

5

What is the chloride (Cl-) concentration in pancreatic fluid?

75

What is the bicarbonate (HCO3-) concentration in pancreatic fluid?

115

What is the normal daily volume of pancreatic secretions?

1,000 mL

What is the osmolality of pancreatic fluid?

280

What is the sodium (Na+) concentration in bile?

145

What is the potassium (K+) concentration in bile?

5

What is the chloride (Cl-) concentration in bile?

100

What is the bicarbonate (HCO3-) concentration in bile?

35

What is the normal daily volume of bile?

1,000 mL

What is the osmolality of bile?

280

What is the sodium (Na+) concentration in sweat?

50

What is the potassium (K+) concentration in sweat?

5

What is the chloride (Cl-) concentration in sweat?

55

What is the baseline daily volume of sweat and how does it change with fever?

500 mL (+350 mL/°C fever)

What is the osmolality of sweat?

Variable

What is the sodium (Na+) concentration in blood?

140

What is the potassium (K+) concentration in blood?

5

What is the chloride (Cl-) concentration in blood?

100

What is the bicarbonate (HCO3-) concentration in blood?

24

What is the normal total blood volume in an average adult?

5,000 mL

What is the osmolality of blood?

280

What is the daily water requirement for a 70kg male?

1,500 to 2,500 mL, or about 25-30 mL/kg body weight

What is the daily requirement for Sodium?

1.0-2.0 mEq/kg

What is the daily requirement for Potassium?

0.5-1.0 mEq/kg

What is the daily requirement for Calcium in average adults, pregnant females, and females over 50 years?

Average adults: 1000 mg/day; Pregnant females: 1300 mg; Females >50 years: 1500 mg

What is the daily requirement for Magnesium in females, pregnant females, and males?

Females: 310-320 mg; Pregnant females: 350-400 mg; Males: 400-420 mg

What is the daily requirement for Phosphate in standard conditions and during severe catabolism/prolonged absence of intake?

Standard: 700 mg; Severe catabolism/prolonged absence of intake: 15 - 25mM per 1000 kcal of glucose

What is the daily requirement for Calorie intake?

1.0-2.0 mEq/kg

What is the most common fluid disorder in surgical patients?

Extracellular Volume Deficit

What clinical signs are associated with an Acute Volume Deficit?

Cardiovascular and central nervous system signs

What clinical signs are displayed in Chronic Volume Deficit in addition to acute signs?

Tissue signs such as decrease in skin turgor and sunken eyes

What is the most common cause of volume deficit in surgical patients?

Loss of GI fluids from nasogastric suction, vomiting, diarrhea, or enterocutaneous fistula

Which conditions cause third-space or nonfunctional ECF losses that lead to massive volume deficits?

Sequestration secondary to soft tissue injuries/infections, burns, intraabdominal processes (peritonitis, obstruction), or prolonged surgery

What are common causes of Extracellular Volume Excess?

Iatrogenic or secondary to renal dysfunction, congestive heart failure, or cirrhosis

Which fluid compartments expand in extracellular volume excess?

Both plasma and interstitial volumes

Which body systems manifest primary symptoms in extracellular volume excess?

Pulmonary and cardiovascular systems

How do elderly patients and patients with cardiac disease tolerate extracellular volume excess compared to healthy patients?

Healthy patients tolerate edema and hyperdynamic circulation well; elderly/cardiac patients may quickly develop congestive heart failure and pulmonary edema

What is the electrolyte composition of Extracellular Fluid (ECF)?

Na+: 142, Cl-: 103, K+: 4, Ca2+: 5, mOsm: 280

What is the electrolyte and caloric composition of Lactated Ringer's (LR)?

Na+: 130, Cl-: 109, K+: 4, Ca2+: 3, Other: Lactate 28 mEq/L, mOsm: 280

What is the electrolyte composition of 0.9% PNSS?

Na+: 154, Cl-: 154, K+: 0, Ca2+: 0, mOsm: 308

What is the electrolyte and caloric composition of D5LR?

Na+: 130, Cl-: 109, K+: 4, Ca2+: 3, Other: Dextrose 50 g/l, Lactate 28 mEq/L, mOsm: 560

What is the electrolyte and caloric composition of D5NS?

Na+: 154, Cl-: 154, K+: 0, Ca2+: 0, Other: Dextrose 50 g/l, mOsm: 588

What is the electrolyte and caloric composition of D5 0.45% NaCl?

Na+: 77, Cl-: 77, K+: 0, Ca2+: 0, Other: Dextrose 50 g/l, mOsm: 434

What is the electrolyte and caloric composition of D5 0.25% NaCl?

Na+: 34, Cl-: 34, K+: 0, Ca2+: 0, Other: Dextrose 50 g/l, mOsm: 357

A 30-year-old man with Crohn's disease of the small bowel with an entero-cutaneous fistula producing 2 L daily output will have fluid lost with what approximate electrolyte composition?

Na: 140, K: 5, Cl: 104, HCO3: 30

According to the Holliday-Segar Method, what is the fluid volume per hour for the first 10 kg of body weight?

4 mL/kg/hr

According to the Holliday-Segar Method, what is the fluid volume per day for the first 10 kg of body weight?

100 mL/kg/day

According to the Holliday-Segar Method, what is the fluid volume per hour for the next 10-20 kg of body weight?

2 mL/kg/hr

According to the Holliday-Segar Method, what is the fluid volume per day for the next 10-20 kg of body weight?

50 mL/kg/day

According to the Holliday-Segar Method, what is the fluid volume per hour for each kg >20 kg?

1 mL/kg/hr

According to the Holliday-Segar Method, what is the fluid volume per day for each kg >20 kg?

20 mL/kg/day