Moving the Patient in Bed

Conscious people assume positions that are the most comfortable. Bedridden patients with acute or chronic respiratory dysfunction often assume an upright position, with their arms flexed and their thorax leaning forward. This position helps decrease their work of breathing. In other cases, patients may have to assume certain positions for therapeutic reasons such as when postural drainage is applied.

Figure 3-3 shows the correct technique for lateral movement of a bed-bound patient. Figure 3-4 illustrates the ideal method for moving a conscious patient toward the head of a bed. Figure 3-5 shows the proper technique for assisting a patient to the bedside position for dangling his or her legs or transfer to a chair.

Ambulation

Ambulation (walking) helps maintain normal body function. Extended bed rest can cause numerous problems, including bed sores and atelectasis (low lung volumes). Ambulation should begin as soon as the patient is physiologically stable and free of severe pain. Ambulation has been shown to reduce the length of hospital stay after surgery and in patients recovering from community-acquired pneumonia.1,2 Safe patient movement includes the following steps:

Monitor the patient during ambulation. Note the patient’s level of consciousness, color, breathing, strength or weakness, and complaints such as pain or shortness of breath throughout the activity. Ask the patient about his or her comfort level frequently during the ambulation period. Ensure that chairs are present so that emergency seats are available if the patient becomes distressed. Ambulation is increased gradually until the patient is ready to be discharged. Each ambulation session is documented in the patient chart and includes the date and time of ambulation, length of ambulation, and degree of patient tolerance.

Fundamentals of Electricity

The ability of humans to create and harness electricity is one of the most important developments in modern times. Because controlled electricity is available on a 24-hour-a-day basis, we can depend on it to power the equipment and appliances that make modern life comfortable and productive. Despite the fact that electricity is one of the most popular sources of power, most people who use it have a poor understanding of it. This lack of knowledge is often a major factor in cases of electrocution.

Electricity moves from point A to point B owing to differences in voltage. Voltage is the power potential behind the electrical energy. Low-voltage batteries (e.g., 9 V) are sufficient to power a small flashlight but inadequate to power a major appliance such as a microwave oven. Most homes and hospitals are powered with 120-V power sources. Power sources that have high voltage have the potential to generate large amounts of electrical current. The current that moves through an object is directly related to the voltage difference between point A and point B and inversely related to the resistance offered by the makeup of the object. Objects with low resistance (e.g., copper wires) allow maximum current to flow through the object. Objects with high resistance (e.g., rubber tubing) allow minimal or no current to flow through the object despite higher levels of voltage.

The simple analogy of water flowing through a piping system is useful to understand electricity. The water pressure level at the source is equivalent to the voltage. Higher water pressure provides the potential for greater water flow or current. The friction (resistance) offered by the pipe across the length of the pipe influences the flow exiting the other end. Pipes with lots of friction reduce the water flow (current) greatly. If the friction (resistance) is minimal, the water flow (current) is maximal. Similarly, when voltage is high and resistance is low, electrical current flows easily through the object.

The difference in resistance between two people or two objects explains why the same voltage applied to both can seriously damage one and cause no effect to the other. Two people accidentally touching a “hot” wire with 120 V can experience two completely different sensations. A person with wet skin offers little resistance, and the 120 V passes through the person with high current and can cause serious injury or death. A person with dry skin, which offers high resistance, may not even feel a shock and experiences no injury. The degree of resistance offered by the skin varies from person to person based on the chemistry of the person’s skin, the cleanliness of the skin, and the amount of moisture on the surface. For this reason, it is never wise to touch a potentially hot wire even though your skin is dry.

As stated before, voltage is the energy potential from an electrical source, and it is measured with a voltmeter. Current is the flow of electricity from a point of higher voltage to one of lower voltage and is reported in amperes (amps). Current is measured with an ampmeter. The resistance to electrical current is reported in ohms. We can determine the resistance to current for any object by the following equation:

Resistance(ohms[Ω])=Voltage(V)/Current(amps[A])

Current represents the greatest danger to you or your patients when electrical shorts occur. Voltage and resistance are important only because they determine how much current potentially can pass through the body. High voltage provides greater potential for high currents, but if resistance is also very high, current would be minimal or nonexistent. Current represents the potential danger to the patient. The harmful effects of current depend on (1) the amount of current flowing through the body, (2) the path it takes, and (3) the duration the current is applied. Higher currents (>100 milliamps [mA]) that pass through the chest can cause ventricular fibrillation, diaphragm dysfunction (owing to severe, persistent contraction), and death.

Because current is most important, you should be familiar with the equation used to calculate it:

Current(A)=Voltage(V)/Resistance(Ω)

For example, as long as a person is insulated by normal clothing and shoes and is in a dry environment, a 120-V shock may hardly be felt because the resistance is high in this situation (10,000 Ω). Current can be calculated as:

Current(A)=120V/10,000Ω=0.012A or12mA

Currents of 12 mA would cause a tingling sensation but no physical damage.

However, if the same person is standing without shoes on a wet floor, a much higher current occurs because the resistance is much lower (1000 Ω). The current is now calculated as:

Current(A)=120V/1000Ω=0.12A or120mA

Because the heart is susceptible to any current level greater than 100 mA, 120 mA represents a potentially fatal shock; this is in sharp contrast to the first example, where the same voltage caused only a tingling sensation.

A shock hazard exists only if the electrical “circuit” through the body is complete, meaning that two electrical connections to the body are required for a shock to occur. In the previous example, the person standing in water with no shoes has “grounded” himself. The finger touching the hot wire provides the input source while the feet standing in water provide the exit to ground. If the same person is wearing rubber boots, the connection to ground does not exist, and the current cannot flow through the individual.

In electrical devices, these two connections typically consist of a “hot” wire and a “neutral” wire. The neutral wire completes the circuit by taking the electrical current to a ground. A ground is simply a low-resistance pathway to a point of zero voltage, such as the earth (hence the term “ground”).

Figure 3-6 shows how current can flow through the body. In this case, a piece of electrical equipment is connected to AC line power via a standard three-prong plug. However, unknown to the practitioner, the cord has a broken ground wire. Normally, current leakage from the equipment would flow back to the ground through the ground wire. However, this pathway is unavailable. Instead, the leakage current finds a path of low resistance through the practitioner to the damp floor (an ideal ground).

Current can readily flow into the body, causing damage to vital organs when the skin is bypassed via conductors such as pacemaker wires or saline-filled intravascular catheters (Figures 3-7 and 3-8). Even urinary catheters can provide a path for current flow. The heart is particularly sensitive to electrical shock. Ventricular fibrillation can occur when currents of 20 µA (20 microamperes, or 20 millionths of 1 ampere) are applied directly to the heart.

Electrical shocks are classified into two types: macroshock and microshock. A macroshock exists when a high current (usually >1 mA) is applied externally to the skin. A microshock exists when a small, usually imperceptible current (<1 mA) bypasses the skin and follows a direct, low-resistance path into the body. Patients susceptible to microshock hazards are termed electrically sensitive or electrically susceptible. Table 3-1 summarizes the different effects of these two types of electrical shock.

Preventing Shock Hazards

Most shock hazards are caused by inappropriate or inadequate grounding. Shock hazards can be eliminated or minimized if wiring in patient care areas is appropriate and if all equipment brought into the patient care area has been UL approved and checked on a regular basis by a qualified person.