Surgical Nursing Notes

Surgical Nursing

Core Objectives of Patient Monitoring

  • Central Nervous System (CNS) Evaluation: The primary goal is to evaluate the depth of anesthesia and the function of the central nervous system.

  • Respiratory System Evaluation: Evaluate the function and efficiency of the respiratory system.

  • Cardiovascular System Evaluation: Evaluate the function and efficiency of the cardiovascular system.

  • Pain Level Evaluation: Determine and monitor the level of pain the patient is experiencing.

Information Sources for Evaluating Patient Status

  • Pre-existing Knowledge: Understanding the specific condition of the patient, the nature of the surgical procedure being performed, and the specific anesthetic protocol being utilized.

  • Hands-on Observation: Direct physical assessment and observation of the patient's physical state.

  • Anesthetic Machine Observation: Monitoring the operation and settings of the anesthetic delivery system.

  • Monitoring Equipment:      Electronic and mechanical monitoring equipment are considered tools.      Crucial Caveat: Monitoring equipment does NOT "monitor" the patient for you; it is an aid to the human monitor.

Interconnectivity of Physiological Systems

  • Respiratory System: Functions to oxygenate the blood.

  • Heart/Cardiovascular System: Pumps blood throughout the body and regulates circulation.

  • Central Nervous System (CNS): Regulates the heart and delivers oxygenated information/regulation to all body systems.

  • Kidneys and Other Systems: All body systems are interconnected and must be monitored, including:      Integumentary (INTEG)      Musculoskeletal (MS)      Ear, Eye, Nose, Throat (EENT)      Neurological (NEURO)      Cardiovascular (CV)      Respiratory (RESP)      Gastrointestinal (GI)      Urinary (URIN)      Reproductive (REPRO)      Lymphatic (LYMPH)

Clinical Evaluation of Anesthetic Depth

  • Primary Objective: To evaluate the level of CNS depression.

  • Evaluation Criteria:     

    •  Reflexes: The presence, absence, or strength of specific involuntary responses.     

    •  Ocular Indicators: Eye position and pupil size.     

    •  Muscle Tone: The degree of relaxation in skeletal muscles.     

    •  Surgical Response: The patient's reaction to surgical stimulus.     

    •  Vital Sign Trends: Monitoring changes over time in Respiratory Rate (RR), Heart Rate (HR), and Blood Pressure (BP).

Defining Appropriate Anesthetic Depth

  • Patient State: The patient must be immobile and unconscious.

  • Pain Management: The patient should experience no significant or prolonged pain.

  • Maintenance of Homeostasis:     

    •  Temperature regulation.     

    •  Adequate oxygenation.     

    •  Acid-base balance.     

    •  Stable blood pressure (BP).

Comprehensive Review of Anesthetic Reflexes

  • Pedal Reflex:     

    •  Definition: The patient withdraws the paw when the toes are pinched or squeezed.     

    •  Procedure: The technician must pinch hard.     

    •  Timing: This reflex is usually lost during the induction phase.

  • Pharyngeal Reflex:     

    •  Definition: The patient swallows when the pharynx is stimulated.     

    •  Observation: Watch the ventral neck.     

    •  Elicitation: Gently pull the tongue.     

    •  Recovery: The patient MUST regain this reflex before extubation can occur.

  • Laryngeal Reflex:     

    •  Definition: The epiglottis and arytenoid cartilages close the glottis when the larynx is stimulated.     

    •  Clinical Significance: Endotracheal intubation cannot be performed if this reflex is present.

  • Palpebral Reflex:     

    •  Definition: The patient blinks when the eyelid is tapped.     

    •  Persistence: The medial reflex persists longer than the lateral reflex.

  • Corneal Reflex:     

    •  Definition: The patient blinks and withdraws the eye into the socket when the cornea is stimulated.     

    •  Clinical Use: Only check if the palpebral response is absent; use a drop of saline to stimulate. This is more useful in large animal monitoring.

  • Nystagmus:     

    •  Definition: Involuntary eye movement.     

    •  Species Specificity: Seen only in horses.     

    •  Trend: The movement slows as anesthetic depth increases.

  • Pupillary Light Response (PLR):     

    •  Definition: The pupil constricts when a penlight is shone into the eye.     

    •  Terminologies:         

    •  Miotic: Constricted pupil.         

    •  Mydriatic: Dilated pupil.

  • Anal Reflex:     

    •  Definition: The anal sphincter contracts when the anus is stimulated.     

    •  Clinical Utility: Present except in deep anesthesia; not commonly used for primary monitoring.

Ocular and Muscular Parameters by Anesthetic Depth

Parameter

Light Anesthesia

Surgical (Medium) Anesthesia

Deep Anesthesia

Eye Position

Central

Ventromedial Rotation

Central

Pupil Size

Dilated (excited), then constricts

Constricted

Dilated

  • Jaw Tone:     

    •  Must be relaxed to allow for intubation.     

    •  Should retain some level of tone throughout the duration of anesthesia.     

    •  Note: Difficult to assess in large animals.

  • Skeletal Muscle Tone:     

    •  Gradual loss occurs as anesthetic depth increases.    

    •   Levels: Marked rightarrow Moderate rightarrow Flaccid.

  • Breathing Patterns:     

    •  When intercostal and diaphragmatic muscles become flaccid, the patient develops an abdominal breathing pattern.

  • Lacrimation (Tear Production):     

    •  Tear production ceases under deep anesthesia.     

    •  Not a useful monitoring parameter because eyes should always be lubricated manually by the technician.

The Four Stages and Planes of Anesthesia

Stage I: Voluntary Excitement

  • Patient Status: Conscious; may move or vocalize.

  • Reflexes: All reflexes are present.

  • Muscle Tone: Strong.

  • Vitals: Heart Rate (HR) and Respiratory Rate (RR) may be elevated due to excitement.

Stage II: Involuntary Excitement

  • Patient Status: Unconscious; no voluntary movement.

  • Behaviors: May paddle, swing head, snap, or vocalize.

  • Reflexes: Present.

  • Ocular: Pupils dilated.

  • Muscle Tone: Strong.

  • Breathing: Apneustic breathing pattern may be observed.

  • Warning: Exercise caution when restraining a patient in Stage II.

Stage III: Surgical Anesthesia

  • Plane 1 (Light):    

    •   No vocalization or movement.     

    •  Pedal reflex is depressed.     

    •  Other reflexes present or slightly depressed.     

    •  Pupils constricted; regular respirations.     

    •  HR begins to slow.     

    •  Risk: Patient may rapidly awaken if stimulated.     

    •  Suitability: Only adequate for superficial procedures.

  • Plane 2 (Medium/Surgical):     

    •  Pedal, pharyngeal, and laryngeal reflexes are absent.     

    •  Palpebral reflex is depressed; corneal reflex is present.     

    •  Pupils constricted; eye position is ventromedial.     

    •  Muscle tone is moderate.     

    •  Steady, shallow respirations.     

    •  Surgical Stimulus: HR, RR, and BP may increase in response to stimulus.     

    •  Suitability: Appropriate for most surgical procedures.

  • Plane 3 (Deep):     

    •  HR, RR, and BP are declining.     

    •  Eye position returns to central; pupils begin to dilate.     

    •  Corneal reflex is still present.     

    •  Muscle tone is flaccid; lacrimation is absent.     

    •  Suitability: Necessary only for very painful procedures (e.g., orthopedics, thoracotomy).

Stage IV: Anesthetic Overdose

  • Patient Status: Severe depression of CNS, respiratory, and cardiovascular systems.

  • Reflexes: All reflexes are absent.

  • Ocular: Eyes central; pupils dilated.

  • Breathing: Abdominal breathing pattern followed shortly by respiratory arrest.

  • Vitals: Low BP; may have a compensatory increase in HR initially, followed quickly by cardiac arrest.

  • Action: Immediate steps must be taken to reverse the overdose and support organ function to prevent death.

Monitoring Protocols

  • Frequency: Record vital signs every 5 , {minutes}.

  • Assessment: Evaluate anesthetic depth simultaneously with vital sign recording.

  • Action: Determine if the patient is too deep or too light; advise the surgeon and take appropriate corrective action immediately.

Respiratory Monitoring

Patient Monitoring Goals

  • Evaluation of Depth and CNS: Assessing the depth of anesthesia and the overall function of the Central Nervous System (CNS).

  • Respiratory System Evaluation: Monitoring the function of the respiratory system.

  • Cardiovascular System Evaluation: Monitoring the function of the cardiovascular system.

  • Pain Management: Evaluating the patient's level of pain.

System Interactions and Homeostasis

  • The Regulatory Loop:     

    •  The Respiratory System oxygenates blood and regulates the Central Nervous System.    

    •   The Heart pumps blood; the Cardiovascular System regulates the Kidneys and all body systems.

Respiratory Physiology under Anesthesia

  • Autonomic Control: Respiration is under autonomic control and is essential for maintaining homeostasis.

  • Primary Functions:     

    •  Maintaining adequate levels of O_2.    

    •   Removing excess CO_2.     

    •  Regulating the acid-base balance.

  • Drivers for Respiration (Inspiration):     

    •  uparrow CO_2      downarrow pH      downarrow O_2      Detection locations include the Common Carotid arteries and the Aortic Arch.

  • Anesthesia Complications:     

    •  Atelectasis: Collapse or closure of a lung resulting in reduced or absent gas exchange.     

    •  Hypoxia: A deficiency in the amount of oxygen reaching the tissues.     

    •  Hypercapnea: Excessive carbon dioxide in the bloodstream, typically caused by inadequate respiration.     

    •  Acidosis: An excessively acid condition of the body fluids or tissues.

Factors Compromising Respiratory Function

  • Tidal Volume (V_T): The total amount of air entering or leaving the respiratory tract in a single respiration (measured in {ml/breath}).

  • Alveolar Space:     

    •  Definition: The space within the respiratory tract where gas exchange occurs.    

    •  Awake Patient Volume: 6.5 - 9.75,{ml/kg}.     

    •  Anesthetized Patient Volume: Reduced to 3.5 - 5.25,{ml/kg}.

  • Anatomic and Physiologic Dead Space: Locations in the respiratory tract where gas exchange does not take place (e.g., nasal cavity, trachea, bronchi, bronchiole, and non-perfused alveoli).

  • Mechanical Dead Space:    

    •   Definition: Space within anesthetic equipment including the endotracheal tube extending beyond the incisors, connections to the breathing circuit, capnometer adaptors, and the face mask.     

    •  The gas within the mechanical dead space is the first gas entering the respiratory tract when the patient inhales.     

    •  Clinical Warning: If the mechanical dead space equals or exceeds the alveolar space, the patient cannot eliminate CO_2, leading to hypercapnea and acidosis.

Monitoring Respiratory Parameters

  • Ventilation: Defined as the movement of air in and out of the alveoli.

  • Respiration: Defined as the provision of O_2 and removal of CO_2 from tissue.

  • Respiratory Rate (RR): Measured in breaths per minute.     

    •  Observation methods: Watching the movement of the chest wall or the reservoir bag.     

    •  Bradypnea: Abnormally slow breathing.     

    •  Tachypnea: Abnormally rapid breathing.     

    •  Apnea: Temporary cessation of breathing.

  • Clinical Trends:     

    •  If RR is decreasing, the patient may be entering a plane of anesthesia that is "too deep."     

    •  If RR is increasing, the patient may be waking up.

Normal Vital Sign Reference Table

Species

Temperature (^{circ}{F})

Heart Rate (bpm)

Respiratory Rate (bpm)

SpO_2

ETCO_2 (mm,Hg)

Blood Pressure (BP)

Dog

97 - 100^{circ}{F}

Sm: 70 - 160; Lg: 60 - 140

8 - 20

>95%

40 - 55,mm,Hg

>60,mm,Hg

Cat

97 - 100^{circ}{F}

120 - 180

8 - 20

>95%

40 - 55,mm,Hg

>60,mm,Hg

Horse

97 - 100^{circ}{F}

28 - 40

6 - 12

>95%

40 - 55,mm,Hg

>70,mm,Hg

Cow

97 - 100^{circ}{F}

50 - 80

6 - 12

>95%

40 - 55,mm,Hg

>60,mm,Hg

Understanding Pressure Units

  • Definition: Force exerted per unit area.

  • Conual Units:     

    •  psi (Pounds per Square Inch): Used for Tank pressure and Line pressure.     

    •  cm,H_2O: Used for Ventilation pressure.     

    •  mm,Hg: Used for partial pressures of O_2 and CO_2.

  • Differentiations: 15,psi, 15,mm,Hg, and 15,cm,H_2O are dramatically different pressures and cannot be interchanged.

Pulse Oximetry (SpO_2)

  • Mechanism: Oxygenated blood has different light absorption than deoxygenated blood. The oximeter emits infrared light, and the sensor analyzes the frequency of light passing through/from tissues while detecting pulsations in arterioles.

  • Probe Types:     

    •  Transmission Probe: Placed on hairless, non-pigmented areas (tongue, pinna, lip, toe/toe web, vulva, or prepuce). Clean with alcohol or chlorhexidene after use.     

    •  Reflective Probe: Placed in the esophagus or rectum with a plastic sleeve; must be flush against the tissue wall to function.

  • Protocol for SpO_2 < 95%:     

    •  Check the patient immediately.     

    •  Check vital signs and assess anesthetic depth.     

    •  Confirm oxygen delivery (check flow rate, hose connections, check for ET tube obstruction, ensure the pop-off valve is open).     

    •  Check the probe: moister the tongue or move the probe.

  • Clinical Troubleshooting:     

    •  Poor Perfusion: Caused by Hypothermia, hypotension, or bradycardia (often drug-induced).     

    •  Impaired Oxygenation: Check ET tube position; patient may require ventilatory support if they have poor ventilation or pre-existing lung disease.

Capnography (ETCO_2)

  • Mechanism: Sensor measures infrared light absorption of expired gases. End Tidal CO_2 (ETCO_2) is typically 2 - 5,mm,Hg less than Arterial CO_2 (PaCO_2).

  • Standard Normal: 40 - 55,mm,Hg.

  • Sensor Types:     

    •  Sidestream Sensor: Adds less dead space than a mainstream sensor.

  • Waveform Interpretation and Response:     

    •  Gradually Rising ETCO_2: Most common; usually caused by hypoventilation. Response: Ventilate the patient more often.     

    •  Gradually Decreasing ETCO_2: Rarely a problem unless the patient is on a ventilator. Causes: Excessive ventilator rate/V_T, hypothermia, or decreased metabolism.     

    •  ETCO_2 = 0 (No Waveform): Check ET tube placement; indicates no CO_2 is reaching the probe.     

    •  Elevated Baseline: Indicates the patient is rebreathing CO_2; check the anesthetic machine.     

    •  Sudden Drop to 20 - 30,mm,Hg: This may indicate impending cardiac arrest. Notify the DVM immediately.

Supporting Respiratory Function

  • Balanced Anesthesia: Utilize multiple agents to minimize general respiratory depression.

  • Equipment Management: Select and maintain equipment to minimize mechanical dead spaces.

  • Positive Pressure Ventilation (PPV): Can be intermittent or continuous. The rate of PPV should be adjusted based on recorded ETCO_2 levels.

Cardiovascular Monitoring

Cardiovascular System Integration and Fundamental Functions

  • Systemic Regulation and Interactions:  

    •  - The cardiovascular system does not operate in isolation; it regulates and is regulated by multiple body systems.   

    • - Respiratory System: Works in tandem with the cardiovascular system to oxygenate blood.   

    • - Central Nervous System (CNS): Exerts regulatory control over the heart and vascular tone.   

    • - Kidneys: The cardiovascular system is vital for kidney function, ensuring adequate perfusion for filtration.   

    • - Universal Support: The system supports all body systems including Integumentary, Musculoskeletal, EENT (Eyes, Ears, Nose, Throat), Neurological, Cardiovascular, Respiratory, Gastrointestinal, Urinary, Reproductive, and Lymphatic (mnemonic: INTEG-MS-EENT-NEURO-CV-RESP-GI-URIN-REPRO-LYMPH).

  • Primary Objectives of the Cardiovascular System:   - To pump blood through the body.   - To deliver oxygen to tissues and organs.

Cardiovascular Physiology and Blood Composition

  • Blood Components:   

    • - White Blood Cells: Involved in immune response.   

    • - Red Blood Cells: Responsible for oxygen transport.   

    • - Platelets: Essential for clotting and hemostasis.   

    • - Plasma: The liquid matrix containing water, proteins, and electrolytes.

  • Neural Control Centers:   

    • - Cardiovascular function is influenced by the Cerebral Cortex, Corpus Callosum, Diencephalon, Mesencephalon, Pons, and Cerebellum.   

    • - Medulla Oblongata: The primary control center for heart rate and blood pressure regulation.

  • Hemodynamic Dynamics:   

    • - Vasoconstriction: Narrowing of blood vessels to increase blood pressure (BP).  

    • - Vasodilation: Widening of blood vessels to decrease blood pressure (BP).   

    • - Cardiac Output Factors: Regulated by Heart Rate (HR) and Contractility.     

    • - Increase in HR and contractility leads to increased Cardiac Output.     

    • - Decrease in HR and contractility leads to decreased Cardiac Output.

  • Key Arterial Anatomy: Includes the Right and Left Common Carotid, Brachiocephalic, Subclavian, and the Aortic Arch.

Impact of Anesthetic Agents on Cardiovascular Physiology

  • Isoflurane:  

    •  - Targets the Medulla Oblongata.   

    • - Results in decreased Heart Rate (HR).   

    • - Results in decreased Contractility.   

    • - Leads to an overall decrease in Cardiac Output.

  • Propofol:   - Acts on neural pathways to cause a decrease in Blood Pressure (BP).

  • Ketamine:  

    •  - Influences the Medulla Oblongata to increase Heart Rate (HR).   

    • - Increases myocardial contractility.   

    • - Leads to an overall increase in Cardiac Output.

Factors Compromising Cardiovascular Function Under Anesthesia

  • Hypovolemia: A state of low blood volume caused by:   

    • - Pre-surgical fasting (patient is fasted before the procedure).   

    • - Intraoperative blood loss.   

    • - Evaporative loss through the respiratory tract.   

    • - Evaporative loss through the incision site.

  • Decreased Venous Return: Reduced volume of blood reaching the heart.

  • Vasodilation: Often induced by anesthetic agents, reducing systemic vascular resistance.

  • Positive Pressure Ventilation: Can impede venous return to the heart, impacting cardiac output.

Cardiovascular Monitoring Parameters and Vital Sign Ranges

  • Monitoring Methods:   

    • - Heart Rate: Measured via auscultation.   

    • - Heart Rhythm: Monitored via Electrocardiogram (ECG).   

    • - Pulse Rate: Assessed by palpating a peripheral pulse.   

    • - Pulse Strength: Assessed by palpating a peripheral pulse.   

    • - Blood Pressure: Measured through direct or indirect monitoring methods.   

    • - Mucous Membrane (mm) Color: Visual assessment of perfusion.   

    • - Capillary Refill Time (CRT): Assessment of peripheral tissue perfusion.

  • Vital Sign Reference Table:   

    • - Dog:     

      • - Temperature: 97-100^circ F     - Heart Rate (Small): 70-160,BPM     - Heart Rate (Large): 60-140,BPM     - Respiratory Rate: 8-20,breaths/min     - SpO2: >95%     - ETCO2: 40-55,mm,Hg     - Blood Pressure (MAP): >60,mm,Hg   

    • - Cat:    

      •  - Temperature: 97-100^circ F     - Heart Rate: 120-180,BPM     - Respiratory Rate: 8-20,breaths/min     - SpO2: >95%     - ETCO2: 40-55,mm,Hg     - Blood Pressure (MAP): >60,mm,Hg   

    • - Horse:     

      • - Temperature: 97-100^circ F     - Heart Rate: 28-40,BPM     - Respiratory Rate: 6-12,breaths/min     - SpO2: >95%     - ETCO2: 40-55,mm,Hg     - Blood Pressure (MAP): >70,mm,Hg   

    • - Cow:     

      • - Temperature: 97-100^circ F     - Heart Rate: 50-80,BPM     - Respiratory Rate: 6-12,breaths/min     - SpO2: >95%     - ETCO2: 40-55,mm,Hg     - Blood Pressure (MAP): >60,mm,Hg

Monitoring Devices in Anesthesia

  • Esophageal Stethoscope: Inserted into the esophagus to allow continuous auscultation of heart and lung sounds close to the heart.

  • Pulse Oximeter: Provides both oxygen saturation (SpO_2) and pulse rate.

  • Doppler Monitor: Uses ultrasonic waves to detect blood flow; used for indirect blood pressure and pulse monitoring.

  • Blood Pressure Monitor: Measures systemic arterial pressures.

  • ECG (Electrocardiogram): Records the electrical activity of the heart.

Electrocardiography (ECG) Principles and Interpretation

  • Basic Principles:   

    • - ECG records the voltage gradients produced by the depolarization and repolarization of the atria and ventricles.   

    • - It records changing voltage over time.   

    • - Crucial Distinction: The ECG does NOT monitor the actual mechanical heartbeat or contraction; it only monitors the electrical rhythm.

  • Conduction Pathway:   

    • 1. SA Node (Sinoatrial Node)   

    • 2. Atria   

    • 3. AV Node (Atrioventricular Node)   

    • 4. Bundle of His   

    • 5. Ventricles (Purkinje fibers, following the interventricular septum)

  • The PQRST Complex Components:  

    •  - P wave: Atrial depolarization.   

    • - PR interval: The time from the start of atrial depolarization to the start of ventricular depolarization.   

    • - QRS complex: Ventricular depolarization.   

    • - ST segment: The interval between ventricular depolarization and repolarization.   

    • - T wave: Ventricular repolarization.   

    • - QT interval: Represents the total time for ventricular depolarization and repolarization.

  • Clinical Rhythm Interpretation:   

    • - Normal Sinus Rhythm: A steady rhythm with PQRST complexes of consistent size and form.   

    • - Respiratory Sinus Arrhythmia: Heart rate increases during inhalation (complexes move closer) and decreases during exhalation (complexes move further apart). This is normal in dogs but abnormal in cats.   

    • - Sinus Bradycardia: Normal PQRST configuration, but the rate is slower than the species-specific normal range.   

    • - Sinus Tachycardia: Normal PQRST configuration, but the rate is faster than the species-specific normal range.   

    • - Atrioventricular (AV) Block: The electrical impulse is delayed or blocked at the AV node; characterized by a prolonged PR interval.   

    • - Ventricular Premature Complexes (VPC): Abnormal-looking QRS complexes that occur early and interrupt the regular rhythm.   

    • - Ventricular Tachycardia: A series of 3 or more VPCs in a row. This is dangerous because it significantly reduces cardiac output, as ventricles do not have time to fill with blood between fast beats.

Tissue Perfusion and Clinical Assessment

  • Objective: To ensure adequate oxygen delivery to vital tissues.

  • Critical Sensitivities:   

    • - Kidneys: Highly sensitive to hypoxia (low oxygen levels).   

    • - Horses: Low oxygen in muscle tissue can lead to a serious condition called post-operative myopathy.

  • Assessment Metrics:  

    •  - Mucous Membrane (mm) Color: Should be pink. Pale membranes can indicate anemia, vasoconstriction, hypotension, or hypothermia.   

    • - Capillary Refill Time (CRT): Should be < 2,seconds. Prolonged CRT indicates poor perfusion, which may be due to vasoconstriction, hypotension, or hypothermia.   

    • - Pulse Strength: There should be one pulse felt for every audible heart beat. While pulses should feel strong and steady, a strong pulse does not guarantee that the Mean Arterial Pressure (MAP) is normal or that tissues are adequately perfused.

Blood Pressure (BP) Monitoring and Dynamics

  • Blood Pressure Definitions:   

    • - Systolic BP: Pressure in the arteries when the ventricles contract.   

    • - Diastolic BP: Pressure in the arteries between contractions while the ventricles are filling.   

    • - Mean Arterial Pressure (MAP): The average pressure over the entire cardiac cycle; considered the best indicator of tissue perfusion in the anesthetized patient.

  • MAP Formula:   - MAP = {Diastolic Pressure} + frac{1}{3}({Systolic} - {Diastolic})

  • Hemodynamic Relationships: Blood Pressure increases when any of the following increase:   - Blood Volume   - Heart Rate   - Stroke Volume   - Blood Viscosity   - Peripheral Resistance

  • Monitoring Techniques:   

    • - Direct Monitoring: Requires an arterial catheter. It provides continuous, real-time data and is the most accurate method. It is common in equine anesthesia but technically challenging for small animals.  

    •  - Indirect Monitoring: Non-invasive and provides intermittent readings. Two primary types:     

    • - Doppler: Uses ultrasound to detect flow.     

    • - Oscillometric: Automated device that detects pressure oscillations in the cuff.

Blood Pressure Cuff Selection

  • Requirements: Correct cuff size is essential for accuracy in both Doppler and Oscillometric methods.

  • Sizing Rule: The cuff width should be 30-40% of the diameter of the limb where it is being placed.

  • Measurement Errors:   

    • - Narrow Cuff: Results in a reading that is falsely too high.   

    • - Wide Cuff: Results in a reading that is falsely too low.