Intravenous Therapy & Fluid Management — Advanced Nursing Guide

💧 IV Fluid Physiology

Body Fluid Compartments — Total Body Water (TBW)

TBW = approximately 60% of body weight (e.g., 70 kg patient = ~42 L total body water). Lower in females (~55%) and obese individuals (fat has low water content).

Intracellular Fluid (ICF)

40%

of body weight (~28 L in 70 kg). Inside cells — regulated by Na⁺/K⁺-ATPase pump.

Extracellular Fluid (ECF)

20%

of body weight (~14 L in 70 kg). Divided into plasma and interstitial.

Plasma (Intravascular)

of body weight (~3.5 L). Within blood vessels — directly accessible for IV therapy.

Interstitial Fluid

15%

of body weight (~10.5 L). Between cells — oedema forms when excess accumulates here.

Key Electrolyte Distribution

ICF dominant: K⁺ (140 mmol/L), Mg²⁺, phosphate, protein

ECF dominant: Na⁺ (140 mmol/L), Cl⁻, HCO₃⁻, Ca²⁺

Starling Forces — Fluid Shift Across Capillaries

Fluid movement across the capillary wall is determined by the balance of four pressures (Starling forces):

Forces Promoting Filtration (OUT of capillary)

• Capillary hydrostatic pressure (~32 mmHg arterial end) — pushes fluid out

• Interstitial oncotic pressure (small proteins in interstitium) — pulls fluid out

Forces Promoting Reabsorption (INTO capillary)

• Plasma oncotic pressure (~25 mmHg, albumin) — pulls fluid in

• Interstitial hydrostatic pressure — pushes fluid in

Clinical: Low Albumin

Reduced oncotic pressure → less reabsorption → oedema. Common in liver disease, malnutrition, sepsis.

Clinical: Heart Failure

Raised capillary hydrostatic pressure → excess filtration → pulmonary/peripheral oedema.

Crystalloids vs Colloids — Fluid Distribution

Crystalloids

• Small molecules, cross capillary membrane freely

• Distribute throughout entire ECF (plasma + interstitial)

• Only ~25% stays intravascular after 1 hour

• Risk of oedema with large volumes

Examples: 0.9% NaCl, Hartmann's, 5% glucose

Colloids

• Large molecules (proteins/starches) — cannot cross intact capillary

• Stay intravascular (initially 2–4 hours)

• More efficient plasma expansion per volume given

• More expensive; limited survival evidence vs crystalloids

Examples: Gelatin (Gelofusine), Albumin 4.5%/20%

Osmolarity, Tonicity & Dehydration Types

Osmolarity vs Tonicity

Osmolarity: total solute concentration (including ineffective osmoles like urea). Normal serum: 275–295 mOsm/L.

Tonicity (effective osmolarity): only osmoles that cannot cross cell membranes (mainly Na⁺, glucose). Determines cell volume/water shift.

Daily Fluid Requirements

• Maintenance: 30–35 ml/kg/day

• Urine output target: ≥0.5 ml/kg/hr

• Insensible losses: 500–700 ml/day (skin/breathing) — increases with fever (+10–15% per °C above 37°C)

• Additional: surgical drains, NGT output, stoma

Dehydration Type	Serum Na⁺	Cause	Cell Volume	IV Replacement Strategy
Isotonic	Normal (135–145)	Vomiting, diarrhoea, haemorrhage	Unchanged	0.9% NaCl or Hartmann's
Hypotonic	Low (<135)	Excess free water, SIADH, excessive 5% glucose	Swollen (water moves in)	Fluid restriction ± hypertonic saline (severe)
Hypertonic	High (>145)	Inadequate water intake, diabetes insipidus, heat stroke	Shrunken (water moves out)	Free water replacement (5% glucose or 0.45% NaCl) — slowly

🧪 IV Fluid Types & Selection

0.9% Sodium Chloride — Normal Saline

308 mOsm/L (Isotonic)

Composition

Na⁺: 154 mmol/L
Cl⁻: 154 mmol/L
No K⁺, no glucose

Indications

Fluid resuscitation, hypovolaemia, dilution of IV drugs, hyponatraemia (cautiously)

Hazards

Hyperchloraemic metabolic acidosis with large volumes (>2L). Hypernatraemia risk. Avoid in head injury (hyperosmolar).

GCC Note

Historically overused in GCC hospitals. Now evidence supports balanced crystalloids as first choice.

Hartmann's Solution / Ringer's Lactate

278 mOsm/L (Balanced)

Composition

Na⁺: 131 mmol/L
Cl⁻: 111 mmol/L
K⁺: 5 mmol/L
Ca²⁺: 2 mmol/L
Lactate: 29 mmol/L

Advantages

Closer to plasma composition. Lactate metabolised to bicarbonate in liver. Reduces hyperchloraemic acidosis vs 0.9% NaCl.

Preferred for

Most IV resuscitation scenarios. Peri-operative fluid therapy. Burns resuscitation (Parkland formula).

Cautions

Contains K⁺ — use cautiously in hyperkalaemia. Avoid with blood transfusion (contains Ca²⁺ — may clot). Liver failure (cannot metabolise lactate).

5% Glucose (Dextrose)

278 mOsm/L → Free Water

Nature

Glucose metabolised rapidly → effectively free water distributed to all body compartments (ICF and ECF).

Use

Maintenance fluid. Free water replacement in hypernatraemia. Hypoglycaemia management (10%, 20%, 50% concentrations).

Dangers

DO NOT use for resuscitation. Hyponatraemia if excessive. Worsens cerebral oedema. Hyperglycaemia in sepsis/DM.

Colloid Fluids

Gelatin Solutions (Gelofusine, Haemaccel)

• Modified bovine gelatin

• Stays intravascular 2–3 hours

• Expensive — limited evidence over crystalloids

• Risk: anaphylaxis, coagulopathy

Not recommended in sepsis (NICE/SSC guidelines now favour crystalloids)

Albumin 4.5% (Human)

• Natural colloid — plasma protein

• Stays intravascular ~16 hours

• SAFE trial: safe alternative to saline in ICU

• Very expensive — reserved for specific indications

Used in: SBP prophylaxis in cirrhosis, paracentesis replacement

20% Albumin (Concentrated)

• Hyperoncotic — pulls fluid into intravascular space

• Used in: hypoalbuminaemia (<20 g/L), cirrhosis with ascites, hepatorenal syndrome

• Small volumes (100 ml) given slowly

Risk: fluid overload, pulmonary oedema if given too fast

Hypertonic Saline (3%)

• 513 mOsm/L — pulls water from ICF to ECF

• Indications: raised ICP (TBI), severe symptomatic hyponatraemia

• Central line only — causes severe phlebitis peripherally

Max correction: 1–2 mmol/L/hr, no more than 8–10 mmol/L/day

Quick Reference: Fluid Composition Comparison

Fluid	Na⁺	Cl⁻	K⁺	Other	Osmolarity	pH
Plasma	140	100	4	HCO₃ 24, Albumin	290	7.4
0.9% NaCl	154	154	0	—	308	5.0
Hartmann's	131	111	5	Ca²⁺ 2, Lactate 29	278	6.5
5% Glucose	0	0	0	Glucose 50g/L	278	4.0
3% NaCl	513	513	0	—	1026	5.0

🚑 Fluid Resuscitation Protocols

NICE IV Fluid Guidance — The 4 Ds

Drug

Select the right fluid type based on clinical indication. Treat IV fluids as medications.

Dose

Prescribe appropriate volume — not too much, not too little. Reassess after each fluid challenge.

Duration

Specify rate and duration — avoid giving resuscitation fluid as maintenance or vice versa.

Documentation

Record fluid balance charts, daily weights, U&E monitoring. Nursing responsibility to document accurately.

Three Phases of IV Fluid Therapy

1. Resuscitation

• Rapidly restore circulating volume

• 500 ml crystalloid bolus over 15 minutes

• Use: Hartmann's or 0.9% NaCl

• Reassess after each bolus — is patient responding?

• Consider source control (sepsis: antibiotics, haemorrhage: surgical control)

STOP when: HR <100, BP improving, UO improving, CRT <2s

2. Replacement

• Replace ongoing abnormal losses

• Surgical drains, NGT output, stoma losses

• Match fluid type to what is lost:

– Gastric (HCl): 0.9% NaCl + KCl

– Intestinal: Hartmann's

– Blood: crossmatch + blood products

Monitor electrolytes with replacement

3. Maintenance (NICE)

• 25–30 ml/kg/day water

• 1 mmol/kg/day sodium, potassium, chloride

• 50–100 g/day glucose (protein-sparing)

• Typical regimen: 0.9% NaCl + 20 mmol KCl (1L over 8h) alternating with 5% glucose

Review daily — wean to oral/NG as soon as possible

Clinical & Monitoring Assessment After Fluid Administration

Bedside Clinical Assessment

Heart rate

Target <100 bpm

Blood pressure

MAP >65 mmHg

Capillary refill

CRT <2 seconds

Skin turgor

Normal tenting = dehydrated

JVP

Elevated = fluid overload

Urine output

≥0.5 ml/kg/hr

Mental status

Confusion = under/overloaded

Lung auscultation

Crackles = overload

Monitoring & Investigations

• Daily U&E — Na⁺, K⁺, creatinine, urea

• FBC — haematocrit (haemoconcentration = dehydration)

• Daily weight — 1 kg ≈ 1 L fluid change

• Fluid balance charts — strict ins and outs

• Serum lactate — marker of tissue perfusion in sepsis

• ABG — acid-base disturbance (hyperchloraemic acidosis)

Nurse role: accurate input/output documentation is critical to clinical decision-making

Dynamic Fluid Responsiveness (ICU)

• Pulse Pressure Variation (PPV) — variation in pulse pressure during mechanical ventilation; PPV >13% = likely fluid responsive

• Stroke Volume Variation (SVV) — measured by cardiac output monitor

• Passive Leg Raise (PLR) — 45° leg elevation auto-transfuses ~300 ml. If CO increases >10% → fluid responsive. Bedside, reversible.

These tools reduce unnecessary fluid administration in ICU — over-resuscitation causes ARDS, renal impairment, abdominal compartment syndrome.

Surviving Sepsis Campaign — Fluid Management

Updated Guidance (2021)

The old "30 ml/kg in first 3 hours" is now outdated. Replaced by guided resuscitation based on clinical response.

• Initial bolus: 1 L crystalloid (0.9% NaCl or Hartmann's) over first hour

• Reassess after each 500 ml bolus using clinical markers

• Balanced crystalloids preferred (Hartmann's) over saline in sepsis

• Avoid starch solutions (HES) — increased renal failure risk

• Target: MAP ≥65 mmHg, lactate clearance, UO ≥0.5 ml/kg/hr

⚡ Electrolyte Replacement

Hypokalaemia — Low Serum K⁺ (<3.5 mmol/L)

Causes & Symptoms

Causes: diuretics (most common), vomiting/diarrhoea, poor intake, hyperaldosteronism, alkalosis, insulin excess

Symptoms: muscle weakness, fatigue, cramps, constipation, arrhythmias, ECG changes (U waves, T wave flattening, prolonged QU)

Treatment Protocol

Mild (3.0–3.5 mmol/L):

Oral KCl: Sando-K (12 mmol/tablet), Slow-K. Dietary: bananas, oranges, potatoes.

Severe (<3.0 mmol/L) or symptoms:

IV KCl infusion — see safety panel below

IV Potassium Safety — HIGH ALERT MEDICATION

• Peripheral maximum rate: 10 mmol/hr

• Central maximum rate: 20 mmol/hr

• NEVER give IV potassium as a bolus — cardiac arrest risk

• Continuous cardiac monitoring (ECG) required during IV KCl

• Never use undiluted concentrated KCl ampoules without dilution

• Always replace Mg²⁺ concurrently

Hypomagnesaemia causes refractory hypokalaemia — K⁺ cannot be corrected until Mg²⁺ is normalised (Mg²⁺ required for Na⁺/K⁺-ATPase function)

• Independent double-check required (GCC hospitals — NPSA/WHO requirement)

• Recheck K⁺ 2–4 hours after IV replacement

Hyperkalaemia — High Serum K⁺ (>5.5 mmol/L)

Emergency Algorithm — ABCDE + ECG Monitoring

STABILISE

Calcium gluconate 10 ml of 10% IV over 2–5 min

Membrane protection — not lowering K⁺

SHIFT

Insulin 10 units + 50 ml 50% glucose IV

Moves K⁺ into cells. Works in 15–30 min.

SHIFT

Salbutamol 10–20 mg nebuliser

β2 agonist drives K⁺ into cells

SHIFT

NaHCO₃ 50 ml 8.4% IV (if acidotic)

Alkalosis drives K⁺ intracellular

REMOVE

Resonium / Patiromer / Dialysis

Definitive removal from body

ECG changes in hyperkalaemia (in order of severity): tall peaked T waves → widened QRS → flattened P waves → sine wave pattern → VF/asystole. Monitor continuously during treatment.

Hyponatraemia — Serum Na⁺ <135 mmol/L

Hypovolaemic

Cause: fluid loss with water replacement (diarrhoea + hypotonic fluid, diuretics, burns)

Tx: 0.9% NaCl cautiously

Euvolaemic (SIADH)

Cause: SIADH (pneumonia, CNS disease, drugs: SSRIs, carbamazepine)

Tx: fluid restriction 500–800 ml/day. Tolvaptan (V2 receptor antagonist) for severe.

Hypervolaemic

Cause: heart failure, cirrhosis, nephrotic syndrome — dilutional hyponatraemia

Tx: treat underlying cause, fluid restriction, diuretics

Critical Safety: Correction Rate

Maximum correction: 8–10 mmol/L per 24 hours (some guidelines: max 10–12 mmol/L/day in severe cases)

Rapid correction of chronic hyponatraemia causes Osmotic Demyelination Syndrome (ODS) — previously called central pontine myelinolysis. Irreversible brainstem damage, locked-in syndrome, death. Correct slowly!

Symptomatic acute hyponatraemia (seizures, coma): may give 150 ml 3% NaCl over 20 min — aim for 5 mmol/L increase only, then stop and reassess.

Hypomagnesaemia — Serum Mg²⁺ <0.7 mmol/L

Causes

Diuretics (especially loop diuretics), alcohol excess, malnutrition, prolonged IV therapy without Mg²⁺, PPIs (proton pump inhibitors), diarrhoea

Clinical Significance

Causes refractory hypokalaemia and hypocalcaemia. Associated with arrhythmias (Torsades de Pointes), tremor, seizures, muscle weakness.

IV Replacement

MgSO₄ 10–20 mmol diluted in 100–250 ml NaCl over 1–2 hours

Monitor: BP, heart rate, deep tendon reflexes (loss = toxicity)
Antidote: IV calcium gluconate

🛡️ IV Drug Administration Safety

10 Rights of Medication Administration

Right Patient

2 identifiers: name + DOB/MRN

Right Drug

Check generic & brand name

Right Dose

Calculate & verify independently

Right Route

IV vs IM vs SC vs oral

Right Time

Prescribed schedule, infusion rate

Right Documentation

Sign after — never before

Right Reason

Know why the drug is given

Right Response

Monitor for expected effect

Right Education

Inform patient of drug & effects

Right to Refuse

Patient autonomy — document refusal

High-Alert IV Medications — Independent Double-Check Required

Medication	Risk	Safety Requirement
Concentrated KCl	Cardiac arrest if given undiluted IV bolus	Independent double-check; max rate 10 mmol/hr peripheral, 20 mmol/hr central; ECG monitor
Insulin IV infusions	Hypoglycaemia — coma, brain damage, death	Hourly BGL monitoring; dedicated insulin protocol; independent double-check of concentration and rate
Heparin IV infusions	Major haemorrhage; overdose → death	aPTT monitoring; independent double-check; antidote: protamine sulphate
Concentrated NaCl (3%+)	Rapid Na⁺ rise → osmotic demyelination	Central line only; strict rate control; serum Na⁺ monitoring q2h
Neuromuscular Blockers	Respiratory arrest if given without ventilation support	ICU/anaesthesia only; never on general wards; independent double-check; prominently labelled
Chemotherapy agents	Extravasation → severe tissue necrosis	Specialist nurse administration; patent IV site confirmed; extravasation protocol ready

Infusion Rate Calculations

Formula: ml/hr

ml/hr = Volume (ml) ÷ Time (hours)

Example: 1000 ml over 8 hours = 125 ml/hr

Formula: Drops/min (gravity drip)

Drops/min = (Volume × Drop factor) ÷ Time (min)

Macrodrip: 20 drops/ml | Microdrip: 60 drops/ml

Example: 500 ml over 4h with macrodrip = (500×20)÷240 = 41.7 ≈ 42 drops/min

Pump vs Gravity Drip

Infusion pumps: anti-siphon valve, free-flow protection, air-in-line alarm, occlusion alarm. Always preferred for high-alert medications. Gravity drips: verify drop rate every 15–30 min — patient movement changes flow.

VIP Score — Visual Infusion Phlebitis Score

Score	Signs	Action
0	No signs of phlebitis	Observe cannula
1	Slight pain or redness	Observe cannula
2	Pain + redness or swelling	Re-site cannula
3	Pain, redness, hardness, streak	Re-site + review
4	As above + palpable cord	Re-site + treat
5	As above + pyrexia/purulence	Re-site + culture + antibiotics

Extravasation Management

Vesicants (anthracyclines, vincristine, doxorubicin): Stop infusion immediately, aspirate, remove cannula, cold compress, specific antidote (dexrazoxane for anthracyclines). Do NOT apply heat.
Non-vesicants: Stop, elevate limb, warm compress, monitor.

🌍 GCC Context & Exam Preparation

GCC-Specific Clinical Considerations

Prescribing Roles & Nursing Responsibility

IV fluid prescribing is the responsibility of doctors in GCC hospitals. The nursing role is in: safe administration, rate verification, site monitoring, fluid balance documentation, recognising and escalating adverse effects. Nurses do not independently prescribe IV fluids but must know correct administration parameters.

Heat-Related Dehydration — GCC Climate

Extreme heat common in GCC (summer temperatures 45–50°C). High-risk groups: outdoor/construction workers, Hajj pilgrims, elderly. Presentations include isotonic and hypertonic dehydration, heat exhaustion, heat stroke. IV resuscitation with 0.9% NaCl or Hartmann's, cooling measures, electrolyte monitoring.

Hajj Medicine — Mass Casualty Fluid Management

Hajj in Mecca (2–3 million pilgrims annually) presents unique mass casualty dehydration scenarios. Heat stroke, heat exhaustion, and dehydration common — often in elderly pilgrims with comorbidities. GCC nurses must know: rapid triage, IV access priorities, fluid resuscitation protocols for mass events, monitoring limitations, and when to escalate.

Normal Saline Overuse — GCC Practice Issue

Large volume normal saline has historically been overused in GCC hospitals. This is clinically significant because it causes hyperchloraemic metabolic acidosis (NAGMA — non-anion gap). Risk is highest in surgical and ICU patients receiving >2L. Balanced crystalloids (Hartmann's) are now internationally preferred. Nurses should recognise unexplained metabolic acidosis in patients receiving large volumes of 0.9% NaCl.

Regulatory Standards — DHA / DOH / CBAHI / SCFHS

DHA (Dubai Health Authority)

Regulates healthcare in Dubai. DHA nursing exams test IV fluid therapy, infusion calculations, electrolyte management, and high-alert medication protocols. Licensure requires demonstrating competency in IV drug administration safety.

DOH (Department of Health — Abu Dhabi)

Abu Dhabi healthcare regulation. DOH standards include mandatory double-check for high-alert IV medications, fluid balance documentation requirements, and IV site monitoring protocols aligned with NPSA/WHO recommendations.

CBAHI (Saudi Arabia Accreditation)

Centre for Healthcare Quality Accreditation in Saudi Arabia. CBAHI accreditation standards require: high-alert medication policy, potassium safety incidents reporting, independent double-check systems, IV site monitoring protocols, and annual competency assessment.

SCFHS (Saudi Commission)

Saudi Commission for Health Specialties — nursing exam includes IV therapy competency assessment. Key topics: fluid types and osmolarity, electrolyte replacement rates, infusion rate calculations, high-alert medications, VIP scoring, extravasation management.

Exam Quick-Reference — High-Yield Facts

Fluid Physiology Numbers to Know

TBW60% body weight

ICF40% body weight

ECF (plasma+interstitial)20% body weight

Plasma volume5% body weight (~3.5L)

Normal serum Na⁺135–145 mmol/L

Normal serum K⁺3.5–5.0 mmol/L

Maintenance fluid30–35 ml/kg/day

Min urine output0.5 ml/kg/hr

Insensible losses500–700 ml/day

Critical Safety Numbers

Max peripheral K⁺ rate10 mmol/hr

Max central K⁺ rate20 mmol/hr

Max Na⁺ correction/24h8–10 mmol/L

Resuscitation bolus500 ml over 15 min

VIP score → re-site≥2

Macrodrip factor20 drops/ml

Microdrip factor60 drops/ml

Normal saline osmolarity308 mOsm/L

Hartmann's osmolarity278 mOsm/L

🧮

IV Fluid Rate Calculator

Fluid Type

Volume (ml)

Time (hours)

Patient Weight (kg)

Indication