Infusion pump

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A type of infusion pump, manufactured by Fresenius. Infusionspumpe.JPG
A type of infusion pump, manufactured by Fresenius.

An infusion pump infuses fluids, medication or nutrients into a patient's circulatory system. It is generally used intravenously, although subcutaneous, arterial and epidural infusions are occasionally used.

Contents

Infusion pumps can administer fluids in ways that would be impractically expensive or unreliable if performed manually by nursing staff. For example, they can administer as little as 0.1 mL per hour injections (too small for a drip), injections every minute, injections with repeated boluses requested by the patient, up to maximum number per hour (e.g. in patient-controlled analgesia), or fluids whose volumes vary by the time of day.

Because they can also produce quite high but controlled pressures, they can inject controlled amounts of fluids subcutaneously (beneath the skin), or epidurally (just within the surface of the central nervous system – a very popular local spinal anesthesia for childbirth).

Types of infusion

The user interface of pumps usually requests details on the type of infusion from the technician or nurse that sets them up:

To get the entire dose of antibiotics into the patient, the "volume to be infused" or VTBI must be programmed for at least 30 CCs more than is in the medication bag; failure to do so can potentially result in up to half of the antibiotic being left in the IV tubing.

Some pumps offer modes in which the amounts can be scaled or controlled based on the time of day. This allows for circadian cycles which may be required for certain types of medication.

Types of pump

A Baxter International Colleague CX infusion pump Baxter Colleague CX infusion pump.JPG
A Baxter International Colleague CX infusion pump
Patient in an intensive care unit in a German hospital in 2015, with two staples of four to five stationary infusion pumps each, on top right behind him (resp. behind the visitor). Patient lying in hospital bed in intensive care unit in Germany in 2015.jpg
Patient in an intensive care unit in a German hospital in 2015, with two staples of four to five stationary infusion pumps each, on top right behind him (resp. behind the visitor).

There are two basic classes of pumps. Large volume pumps can pump fluid replacement such as saline solution, medications such as antibiotics or nutrient solutions large enough to feed a patient. Small-volume pumps infuse hormones, such as insulin, or other medicines, such as opiates.

Within these classes, some pumps are designed to be portable, others are designed to be used in a hospital, and there are special systems for charity and battlefield use.

Large-volume pumps usually use some form of peristaltic pump. Classically, they use computer-controlled rollers compressing a silicone-rubber tube through which the medicine flows. Another common form is a set of fingers that press on the tube in sequence.

Small-volume pumps usually use a computer-controlled motor turning a screw that pushes the plunger on a syringe.

The classic medical improvisation for an infusion pump is to place a blood pressure cuff around a bag of fluid. The battlefield equivalent is to place the bag under the patient. The pressure on the bag sets the infusion pressure. The pressure can actually be read-out at the cuff's indicator. The problem is that the flow varies dramatically with the cuff's pressure (or patient's weight), and the needed pressure varies with the administration route, potentially causing risk when attempted by an individual not trained in this method.

Places that must provide the least-expensive care often use pressurized infusion systems. One common system has a purpose-designed plastic "pressure bottle" pressurized with a large disposable plastic syringe. A combined flow restrictor, air filter and drip chamber helps a nurse set the flow. The parts are reusable, mass-produced sterile plastic, and can be produced by the same machines that make plastic soft-drink bottles and caps. A pressure bottle, restrictor and chamber requires more nursing attention than electronically controlled pumps. In the areas where these are used, nurses are often volunteers, or very inexpensive.

The restrictor and high pressure helps control the flow better than the improvised schemes because the high pressure through the small restrictor orifice reduces the variation of flow caused by patients' blood pressures.

An air filter is an essential safety device in a pressure infusor, to keep air out of the patients' veins. Small bubbles could cause harm in arteries, but in the veins they pass through the heart and leave in the patients' lungs. The air filter is just a membrane that passes gas but not fluid or pathogens. When a large air bubble reaches it, it bleeds off.

Some of the smallest infusion pumps use osmotic power. Basically, a bag of salt solution absorbs water through a membrane, swelling its volume. The bag presses medicine out. The rate is precisely controlled by the salt concentrations and pump volume. Osmotic pumps are usually recharged with a syringe.

Spring-powered clockwork infusion pumps have been developed, and are sometimes still used in veterinary work and for ambulatory small-volume pumps. They generally have one spring to power the infusion, and another for the alarm bell when the infusion completes.

Battlefields often have a need to perfuse large amounts of fluid quickly, with dramatically changing blood pressures and patient condition. Specialized infusion pumps have been designed for this purpose, although they have not been deployed.

Many infusion pumps are controlled by a small embedded system. They are carefully designed so that no single cause of failure can harm the patient. For example, most have batteries in case the wall-socket power fails. Additional hazards are uncontrolled flow causing an overdose, uncontrolled lack of flow, causing an underdose, reverse flow, which can siphon blood from a patient, and air in the line, which can cause an air embolism.

Elastomeric pumps, also known as balloon pumps or ball pumps, rely on the gradual contraction of an internal elastomeric reservoir to deliver medication at a pre-determined flow rate over several hours or days. These pumps do not require electricity and offer simplicity and portability, making them suitable for administering various medications, including antibiotics, in situations where continuous, low-rate infusion is required. These features make them useful for infusions in outpatient settings, such as outpatient parenteral antibiotic therapy (OPAT). However, due to their limited features and programmability, they are not suitable for all medications or flow rates. [1] [2]

Safety features available on some pumps

The range of safety features varies widely with the age and make of the pump. A state of the art pump in 2003 might have had the following safety features:

By 2019 intravenous smart pumps were being introduced. They could include wireless connectivity, drug libraries, profiles of care areas, and soft and hard limits. [3]

Safety issues

Infusion pumps have been a source of multiple patient safety concerns, and problems with such pumps have been linked to more than 56,000 adverse event reports from 2005 to 2009, including at least 500 deaths. [4] As a result, the U.S. Food and Drug Administration (FDA) has launched a comprehensive initiative to improve their safety, called the Infusion Pump Improvement Initiative. [5] The initiative proposed stricter regulation of infusion pumps. It cited software defects, user interface issues, and mechanical or electrical failures as the main causes of adverse events.

See also

Related Research Articles

<span class="mw-page-title-main">Central venous catheter</span> A tubular device placed in a large vein used to administer medicines

A central venous catheter (CVC), also known as a central line (c-line), central venous line, or central venous access catheter, is a catheter placed into a large vein. It is a form of venous access. Placement of larger catheters in more centrally located veins is often needed in critically ill patients, or in those requiring prolonged intravenous therapies, for more reliable vascular access. These catheters are commonly placed in veins in the neck, chest, groin, or through veins in the arms.

<span class="mw-page-title-main">Local anesthetic</span> Medications to reversibly block pain

A local anesthetic (LA) is a medication that causes absence of all sensation in a specific body part without loss of consciousness, providing local anesthesia, as opposed to a general anesthetic, which eliminates all sensation in the entire body and causes unconsciousness. Local anesthetics are most commonly used to eliminate pain during or after surgery. When it is used on specific nerve pathways, paralysis also can be induced.

<span class="mw-page-title-main">Intravenous therapy</span> Medication administered into a vein

Intravenous therapy is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutrients for those who cannot, or will not—due to reduced mental states or otherwise—consume food or water by mouth. It may also be used to administer medications or other medical therapy such as blood products or electrolytes to correct electrolyte imbalances. Attempts at providing intravenous therapy have been recorded as early as the 1400s, but the practice did not become widespread until the 1900s after the development of techniques for safe, effective use.

<span class="mw-page-title-main">Route of administration</span> Path by which a drug, fluid, poison, or other substance is taken into the body

In pharmacology and toxicology, a route of administration is the way by which a drug, fluid, poison, or other substance is taken into the body.

<span class="mw-page-title-main">Subcutaneous administration</span> Insertion of medication under the skin

Subcutaneous administration is the insertion of medications beneath the skin either by injection or infusion.

<span class="mw-page-title-main">General anaesthesia</span> Medically induced loss of consciousness

General anaesthesia (UK) or general anesthesia (US) is a method of medically inducing loss of consciousness that renders a patient unarousable even with painful stimuli. This effect is achieved by administering either intravenous or inhalational general anaesthetic medications, which often act in combination with an analgesic and neuromuscular blocking agent. Spontaneous ventilation is often inadequate during the procedure and intervention is often necessary to protect the airway. General anaesthesia is generally performed in an operating theater to allow surgical procedures that would otherwise be intolerably painful for a patient, or in an intensive care unit or emergency department to facilitate endotracheal intubation and mechanical ventilation in critically ill patients. Depending on the procedure, general anaesthesia may be optional or required. Regardless of whether a patient may prefer to be unconscious or not, certain pain stimuli could result in involuntary responses from the patient that may make an operation extremely difficult. Thus, for many procedures, general anaesthesia is required from a practical perspective.

<span class="mw-page-title-main">Epidural administration</span> Medication injected into the epidural space of the spine

Epidural administration is a method of medication administration in which a medicine is injected into the epidural space around the spinal cord. The epidural route is used by physicians and nurse anesthetists to administer local anesthetic agents, analgesics, diagnostic medicines such as radiocontrast agents, and other medicines such as glucocorticoids. Epidural administration involves the placement of a catheter into the epidural space, which may remain in place for the duration of the treatment. The technique of intentional epidural administration of medication was first described in 1921 by Spanish military surgeon Fidel Pagés.

<span class="mw-page-title-main">Remifentanil</span> Synthetic opioid analgesic

Remifentanil, marketed under the brand name Ultiva is a potent, short-acting synthetic opioid analgesic drug. It is given to patients during surgery to relieve pain and as an adjunct to an anaesthetic. Remifentanil is used for sedation as well as combined with other medications for use in general anesthesia. The use of remifentanil has made possible the use of high-dose opioid and low-dose hypnotic anesthesia, due to synergism between remifentanil and various hypnotic drugs and volatile anesthetics.

<span class="mw-page-title-main">Eye drop</span> Liquid applied directly to the eye

Eye drops or eyedrops are liquid drops applied directly to the surface of the eye usually in small amounts such as a single drop or a few drops. Eye drops usually contain saline to match the salinity of the eye. Drops containing only saline and sometimes a lubricant are often used as artificial tears to treat dry eyes or simple eye irritation such as itching or redness. Eye drops may also contain one or more medications to treat a wide variety of eye diseases. Depending on the condition being treated, they may contain steroids, antihistamines, sympathomimetics, beta receptor blockers, parasympathomimetics, parasympatholytics, prostaglandins, nonsteroidal anti-inflammatory drugs (NSAIDs), antibiotics, antifungals, or topical anesthetics.

<span class="mw-page-title-main">Intraosseous infusion</span> Medication injections into bone marrow

Intraosseous infusion (IO) is the process of injecting medication, fluids, or blood products directly into the bone marrow; this provides a non-collapsible entry point into the systemic venous system. The intraosseous infusion technique is used to provide fluids and medication when intravenous access is not available or not feasible. Intraosseous infusions allow for the administered medications and fluids to go directly into the vascular system. The IO route of fluid and medication administration is an alternative to the preferred intravascular route when the latter cannot be established promptly in emergent situations. Intraosseous infusions are used when people have compromised intravenous access and need immediate delivery of life-saving fluids and medications.

<span class="mw-page-title-main">Syringe driver</span>

A syringe driver, also known as a syringe pump, is a small infusion pump, used to gradually administer small amounts of fluid to a patient or for use in chemical and biomedical research. Some syringe drivers can both infuse and withdraw solutions.

<span class="mw-page-title-main">Paracentesis</span> Form of body fluid sampling procedure

Paracentesis is a form of body fluid sampling procedure, generally referring to peritoneocentesis in which the peritoneal cavity is punctured by a needle to sample peritoneal fluid.

Extravasation is the leakage of intravenously (IV) infused, and potentially damaging, medications into the extravascular tissue around the site of infusion. The leakage can occur through brittle veins in the elderly, through previous venipuncture access, or through direct leakage from wrongly positioned venous access devices. When the leakage is not of harmful consequence it is known as infiltration. Extravasation of medication during intravenous therapy is an adverse event related to therapy that, depending on the medication, amount of exposure, and location, can potentially cause serious injury and permanent harm, such as tissue necrosis. Milder consequences of extravasation include irritation, characterized by symptoms of pain and inflammation, with the clinical signs of warmth, erythema, or tenderness.

A post-anesthesia care unit (PACU) and sometimes referred to as post-anesthesia recovery or PAR, or simply recovery, is a part of hospitals, ambulatory care centers, and other medical facilities. Patients who received general anesthesia, regional anesthesia, or local anesthesia are transferred from the operating room suites to the recovery area. The patients are monitored typically by anesthesiologists, nurse anesthetists, and other medical staff. Providers follow a standardized handoff to the medical PACU staff that includes, which medications were given in the operating room suites, how hemodynamics were during the procedures, and what is expected for their recovery. After initial assessment and stabilization, patients are monitored for any potential complications, until the patient is transferred back to their hospital rooms.

A volume expander is a type of intravenous therapy that has the function of providing volume for the circulatory system. It may be used for fluid replacement or during surgery to prevent nausea and vomiting after surgery.

<span class="mw-page-title-main">Infusion therapy</span> Medical aspects of fluid and medication infusion by therapeutic application

In medicine, infusion therapy deals with all aspects of fluid and medication infusion, via intravenous or subcutaneous application. A special infusion pump can be used for this purpose.

<span class="mw-page-title-main">Patient-controlled analgesia</span> Administration of pain relief medication by a patient

Patient-controlled analgesia (PCA) is any method of allowing a person in pain to administer their own pain relief. The infusion is programmable by the prescriber. If it is programmed and functioning as intended, the machine is unlikely to deliver an overdose of medication. Providers must always observe the first administration of any PCA medication which has not already been administered by the provider to respond to allergic reactions.

<span class="mw-page-title-main">Elastomeric pump</span>

Elastomeric pumps, also called balloon pumps or ball pumps, are usually used in the medical field to administer liquid drugs such as local anesthetics, analgesics, cytostatics or antibiotics.

<span class="mw-page-title-main">Y-Set (intravenous therapy)</span>

In intravenous therapy a Y-Set, T-Set and V-Sets are Y-, T- and V-shaped three-way connector sets made of connecting plastic tubes used for delivering intravenous drugs into the body from multiple fluid sources. As Y-Sets are the most common shaped sets, Y-Set is a name that is sometimes used to represent the family of connector sets. The majority of these infusion sets have a left and right hand line that deliver fluid and drugs to a short common limb attached to the female fitting on the intravenous cannulae.

Total intravenous anesthesia (TIVA) refers to the intravenous administration of anesthetic agents to induce a temporary loss of sensation or awareness. The first study of TIVA was done in 1872 using chloral hydrate, and the common anesthetic agent propofol was licensed in 1986. TIVA is currently employed in various procedures as an alternative technique of general anesthesia in order to improve post-operative recovery.

References

  1. Diamantis S, Dawudi Y, Cassard B, Longuet P, Lesprit P, Gauzit R (February 2021). "Home intravenous antibiotherapy and the proper use of elastomeric pumps: Systematic review of the literature and proposals for improved use". Infectious Diseases Now. 51 (1): 39–49. doi:10.1016/j.medmal.2020.10.019. PMID   33576336. S2CID   230762015.
  2. Spencer-Jones J, Luxton T, Bond SE, Sandoe J (August 2023). "Feasibility, Effectiveness and Safety of Elastomeric Pumps for Delivery of Antibiotics to Adult Hospital Inpatients-A Systematic Review". Antibiotics. 12 (9): 1351. doi: 10.3390/antibiotics12091351 . PMC   10525832 . PMID   37760648.
  3. Davis, S.; Blanchard, C.; Lewis, J. (26 October 2018). "Implementing Smart Pumps to Enhance Patient Safety". Hospital Pharmacy. 54 (4): 217–219. doi:10.1177/0018578718809252. PMC   6628554 . PMID   31320768.
  4. Pharmacy Practice News, May 2010
  5. "White Paper: Infusion Pump Improvement Initiative". FDA. 14 January 2020.