Introduction. Capillary refill time (CRT) is a measure of the time it takes for a distal capillary bed, such as those found in the fingers, to regain colour after pressure has been applied to cause blanching. A prolonged CRT may indicate the presence of circulatory shock.

A capillary refill time of three seconds or more should be considered abnormal. The results show that an abnormal CRT of 3 seconds or more increases the likelihood of a serious outcome including death and dehydration – however a normal CRT does not make a serious outcome less likely.

A prolonged capillary refill time may be a sign of shock and can also indicate dehydration and may be a sign of dengue hemorrhagic fever and decreased peripheral perfusion. Prolonged capillary refill time may also suggest peripheral artery disease.

A delay in the capillary refill time (>2 seconds) indicates hypoperfusion of the skin. Shunting of blood from the capillary beds in the skin is an indication of increased systematic vascular resistance (SVR). An increase in SVR is generally thought to occur early in the course of pediatric hypovolemia.

Definition: The capillary nail refill test is a quick test done on the nail beds. It is used to monitor dehydration and the amount of blood flow to tissue. Pressure is applied to the nail bed until it turns white. This indicates that the blood has been forced from the tissue under the nail.

Problem/Condition. Inadequate perfusion to the extremities refers to decreased arterial blood flow to the extremities. This can be due to a sudden embolic event obstructing arterial flow, or a chronic obstructive process leading to decreased arterial flow to the extremities.

Your fingers, hands, arms, legs, feet, and toes are considered your extremities. Your extremities can display tingling or numbness, swelling, and heaviness. Poor circulation can even lead to gangrene of the extremities, which is the death of body tissue, which can potentially lead to amputation in severe cases.

There is no specific “normal” value for perfusion index, each person should establish their own baseline value and note how it changes over time. A higher perfusion index means greater blood flow to the finger and a lower perfusion index means lower blood flow to the finger.

Discussion: Clinical signs of poor peripheral perfusion consist of a cold, pale, clammy, and mottled skin, associated with an increase in capillary refill time.

According to the World Health Organization (WHO), oxygen saturation (SpO2) should be between 95% and 100%. Less than 90% of oxygen saturation is a clinical emergency. The normal perfusion index (PI) ranges from 0.02% to 20% showing weak to strong pulse strength.

There ‏are different methods to clinically assess the ‏peripheral perfusion.

1. Mottle Score.
2. Capillary Refill Time.
3. Near-Infrared Spectroscopy (NIRS)
4. Direct Visualisation of the Sublingual Microcirculation.
5. Continuous PtcO2 transcutaneous measurement.

The transplanted islets are relying on diffusion of oxygen and nutrients, driven by concentration gradients, contained in the interstitial fluid that is shared with the surrounding (“peripheral”) perfused tissue. Diffusion is not viable for supporting cell metabolism more than a few cell cells away from a blood vessel.

75 to 100 cc/kilo/min. perfusion rate is recommended. Minimal mean arterial pressures (60-70 mmHg) are essential to maintain good function of all organ systems for many hours of perfusion and to avoid disseminated intravascular coagulation by keeping capillary beds open.

In situations where the patient’s peripheral circulation is sluggish, such as in peripheral shutdown due to shock, or local hypothermia, the pulse oximeter may not be able to detect pulsatile movement. This may result in no readings or erroneous readings being produced.

Pulse oximeters are least accurate when oxygen saturations are less than 80%. Use pulse oximeter readings as an estimate of blood oxygen saturation. For example, a pulse oximeter saturation of 90% may represent an arterial blood saturation of 86-94%.

Place the pulse oximeter on your index or middle finger. Keep the pulse oximeter on your finger for at least a minute, till the reading stabilises. Record the highest reading that flashes on the oximeter after it has established after 5 seconds.

Put the probe on your own finger and check it is working! Oximeters need a flow of blood through the finger to function. Some oximeters give an indication of the blood flow detected. In this oximeter there is a scale which is an indication of the blood flow.

During a pulse oximetry reading, a small clamp-like device is placed on a finger, earlobe, or toe. Small beams of light pass through the blood in the finger, measuring the amount of oxygen. It does this by measuring changes of light absorption in oxygenated or deoxygenated blood. This is a painless process.

Tips to Increase Your Blood Oxygen Level Some ways include: Open windows or get outside to breathe fresh air. Something as simple as opening your windows or going for a short walk increases the amount of oxygen that your body brings in, which increases overall blood oxygen level.

Factors that can produce falsely low estimates of arterial hemoglobin saturation by pulse oximetry (SaO 2) include the presence of methemoglobin (1) anemia combined with hypotension (2,3) motion (4), dark skin pigmentation including certain skin dyes (5), blue or green fingernail polish (6), and severe tricuspid …

Normal limits of vital signs: systolic blood pressure 120–90 mmHg, pulse rate 60–100/min, respiration rate 12–16/min, body temperature 36.0°C –37.1°C, and oxygen saturation >94%. Low perfusion index includes scores 0–5; high perfusion index includes scores >5.

Low perfusion is the product of reduced peripheral blood flow and subsequent reduction in the detectable signal at the sensor site.

Baseline PI ranged from 0.7 to 8.6, with a mean value of 4.0 (2.3).

Adequate perfusion is essential: Perfusion is the means by which blood provides nutrients and removes cellular waste. Adequate tissue perfusion-when supply meets demand-is necessary to maintain healthy vital tissue.

In patients with inadequate tissue perfusion and adequate intravascular volume, initiation of inotropic and/or vasopressor drug therapy may be necessary. Dopamine increases myocardial contractility and supports the blood pressure; however, it may increase myocardial oxygen demand.

Symptoms of poor blood flow to the brain

• slurred speech.
• sudden weakness in the limbs.
• difficulty swallowing.
• loss of balance or feeling unbalanced.
• partial or complete loss of vision or double vision.
• dizziness or a spinning sensation.
• numbness or a tingling feeling.
• confusion.