Medical-Surgical Nursing: cram pack

Med-surg: cardiovascular & respiratory

Method

1. Name the problem: pump failure, blocked artery, rhythm, clot, airway narrowing, infection or a device problem.
2. Check the danger signs first: hypoxia, hypotension, chest pain, new confusion, a cold pulseless limb.
3. Match the oxygen to the patient: 94–98% for most, 88–92% for those at risk of CO₂ retention.
4. Link each drug to its test and its risk: warfarin and INR, heparin and aPTT and platelets, diuretics and potassium.
5. Choose the safe first action, then escalate and reassess.

Med-surg: neuro, endocrine & renal

Method

1. Check the glucose in every patient with new confusion, weakness or a seizure.
2. Use the level of consciousness as the earliest warning of brain trouble; pupils and Cushing’s triad come late.
3. For diabetes emergencies, separate DKA (ketones, acidosis) from HHS (very high osmolality, dehydration); give fluids first.
4. For sodium and water, decide whether ADH is in excess (SIADH) or missing (DI), and correct chronic changes slowly.
5. For kidney problems, sort the cause into pre-renal, intrinsic or post-renal, and watch potassium and fluid.

Med-surg: GI, perioperative & oncology

Method

1. Ask what could be hidden: internal bleeding, infection without fever, hypoventilation behind a normal SpO₂.
2. Use the timing after surgery to narrow the complications: bleeding in hours, chest problems in days, wound and leak problems later.
3. For pain, assess, treat with multimodal analgesia, reassess, and monitor sedation with every opioid.
4. For cancer patients, treat any illness during the nadir as neutropenic sepsis and know the oncological emergencies.
5. For burns, count only partial- and full-thickness areas, start the Parkland clock at the time of the burn and titrate to urine output.

Lab values & electrolytes

Method

1. Compare the value with the laboratory’s own reference range, then with the patient’s baseline and trend.
2. Check the sample: hemolysis, a delay, or blood drawn near an IV can give false results.
3. Link the value to its typical signs and to the drugs and conditions that cause it.
4. Look for interactions: low potassium or magnesium increases digoxin toxicity; dehydration raises lithium.
5. Act on the patient: assess, hold a drug if the level is unsafe, read back critical values and inform the prescriber.

Arterial blood gas interpretation

Normal ranges

pH 7.35–7.45, PaCO₂ 35–45 mmHg (4.7–6.0 kPa), HCO₃⁻ 22–26 mmol/L

ROME

Respiratory: PaCO₂ opposite to pH; Metabolic: HCO₃⁻ equal to pH

Winter’s formula

PaCO₂ = 1.5·HCO₃⁻ + 8 ± 2

Metabolic alkalosis

PaCO₂ ≈ 0.7·HCO₃⁻ + 21

Anion gap

AG = Na⁺ − (Cl⁻ + HCO₃⁻) ≈ 8–12

Albumin-corrected gap

AG + 2.5·(4.0 − alb g/dL) = AG + 0.25·(40 − alb g/L)

Delta ratio

(AG − 12)/(24 − HCO₃⁻)

P/F ratio

PaO₂/FiO₂

Alveolar gas equation

PAO₂ = FiO₂·(760 − 47) − PaCO₂/0.8

Serum osmolality

2·Na⁺ + glucose + urea (2·Na⁺ + glucose/18 + BUN/2.8)

Method

1. Read the pH: below 7.35 is acidosis, above 7.45 alkalosis.
2. Find the value that explains it: PaCO₂ moving opposite to the pH is respiratory, HCO₃⁻ moving with the pH is metabolic.
3. Look at the other value: normal means uncompensated, abnormal in the compensating direction means partial compensation, and a normal pH with both abnormal means full compensation.
4. In a metabolic acidosis, compare PaCO₂ with Winter’s formula, 1.5·HCO₃⁻ + 8 ± 2, and calculate the anion gap Na⁺ − (Cl⁻ + HCO₃⁻).
5. Check a high anion gap with the delta ratio and, when albumin is low, with the corrected gap.

ECG rhythm strip interpretation

Paper (25 mm/s, 10 mm/mV)

1 small box = 0.04 s, 1 large box = 0.20 s, 10 mm = 1 mV

Heart rate, regular rhythm

300 ÷ large boxes = 1500 ÷ small boxes = 60 ÷ RR (s)

Heart rate, irregular rhythm

QRS complexes in 6 s × 10

Normal PR interval

0.12–0.20 s

Normal QRS duration

< 0.12 s

QTc (Bazett)

QT/√RR

QTc (Fridericia)

QT/∛RR

QTc (Framingham)

QT + 154·(1 − RR)

Sinus rates

bradycardia < 60, normal 60–100, tachycardia > 100 /min

Escape rates

junctional 40–60, ventricular 20–40 /min

Fast rhythms

SVT 150–250 /min (narrow), VT > 100 /min (wide)

Method

1. Rate: for a regular rhythm divide 300 by the large boxes or 1500 by the small boxes between two R waves; for an irregular rhythm count the QRS complexes in 6 seconds and multiply by 10.
2. Rhythm: compare the R–R intervals. Equal is regular; a repeating pattern is regularly irregular; no pattern at all is irregularly irregular.
3. P waves: is there an upright P wave in lead II before every QRS, all alike? Look for fibrillatory or sawtooth waves, inverted P waves and P waves without a QRS.
4. PR interval: from the start of P to the start of the QRS, normally 0.12–0.20 s and constant. Watch whether it lengthens, stays fixed before a dropped beat, or varies at random.
5. QRS duration: below 0.12 s is narrow; 0.12 s or more is wide. Then name the rhythm, and for the QT use QTc = QT/√RR (Bazett) with times in seconds.

Prioritization & delegation

Method

1. Ask what will harm the patient soonest if nothing is done.
2. Apply ABC (C-A-B in cardiac arrest), then Maslow: physiological needs before safety, safety before psychological needs.
3. Compare the options: acute before chronic, unstable before stable, unexpected before expected, systemic before local, and check each finding against the patient’s baseline.
4. Assess before you act unless it is an emergency; then choose the step the others depend on.
5. For delegation, check the five rights: task, circumstance, person, directions and supervision. Assessment, teaching and evaluation stay with the RN.