Blood Conservation Devices and
Hemostatic Surgical Instruments
- Electrocautery. A device in which an electric current is used to heat a
treatment instrument or probe. The
heated probe cauterizes capillary vessels and small arteries, thus
minimizing blood loss during surgery.
Also called thermal cautery, this device does not transfer any
electric current to the patient.
- Lasers. Instruments similar in principle to electrocautery devices,
but employing laser energy to cut, vaporize, and simultaneously coagulate
a targeted area without disrupting adjacent tissue. Cutting is achieved hemostatically,
making the systems suitable for endoscopic and open surgical
procedures. Lasers promote
clotting by localizing heat in bleeding vessels, resulting in coagulation.
- Microwave Scalpels. Microwaves are a form of
electromagnetic energy that can be used to generate heat. The microwave scalpel is an instrument
that concentrates a localized high-power microwave field around the
leading edge of a scalpel blade.
Because microwave energy is absorbed in tissue, this scalpel can
provide coagulation during surgery on vascular organs such as the spleen
- Argon Beam Coagulator. A surgical instrument that uses a beam
of ionized argon gas (argon “plasma”) to conduct a high-frequency electric
current to bleeding tissues with limited tissue contact. Argon beam coagulation may be used for
the hemostasis of surface, diffuse bleeding from parenchymatous tissues
(e.g., of the liver, spleen).
Minimally Invasive Surgery
An approach to
surgery whereby operations are performed with specialized instruments designed
to be inserted into the patient through small incisions or natural body
openings. This avoids the need for
large incisions, minimizing the bleeding and trauma of surgery to the
body. Miniaturized telescope-like
devices allow surgeons to watch their actions on a television monitor, instead
of looking directly at the part of the body being treated.
- Endoscopy. Endoscopes allow visual examination of the interior of the
stomach, intestines, and other body cavities. Bleeding or other problems can be located, diagnosed, and
treated without conventional open surgery.
- Laparoscopy. Using a small “keyhole” incision, a laparoscope may be used to
visualize the abdomen. Specialized
instruments and techniques adapted for minimally invasive surgery may be
inserted through other nearby small unobtrusive incisions to perform
Blood Recovery/Salvage Devices
Awareness of the
need for blood conservation in the surgical patient and concerns about the
risks of allogeneic blood transfusion have prompted clinicians to make wider
use of the autologous blood recovery techniques. Modern intraoperative and postoperative autotransfusion is
considered to be safe, well tolerated, and cost-effective for a variety of
patients with profuse bleeding.
- Intraoperative Blood Salvage/Recycling Devices
(Autotransfusion). Autologous blood cell salvage (autotransfusion) involves
recovery of some portion of the patient’s shed blood from a wound or body
cavity, washing or filtering, and reinfusion of the blood into the
patient. Reinfusion can be
performed continuously during surgery.
- Postoperative Blood Salvage/Recycling Devices. In some surgical
procedures postoperative blood loss exceeds intraoperative blood
losses. Blood that is shed
postoperatively can be collected from a drainage tube at the surgical
site, processed and returned to the patient.
Minimally and Noninvasive Blood
Diagnostic and Monitoring Systems
- Blood Microsampling. Microsample blood analysis devices use electrochemical,
photometric and other technology to provide immediate critical diagnostic
information at the point of care from only a few drops of blood (a
fraction of the usual quantity).
This reduces cumulative blood losses as well as the time required
to make decisions on patient management that are dependent on the results
of blood tests.
Clinical Oxygen Delivery Systems
- Hyperbaric Oxygen (HBO). Hyperbaric
oxygen therapy is used to manage severe anemia due to sudden blood loss in
order to extend the physiologic limits of the cardiovascular system. HBO therapy is the medical use of
intermittent doses of 100% oxygen at increased atmospheric pressure to a
patient in a sealed environment in order to substantially increase the
level of oxygen dissolved in the blood plasma. Limited availability.
Medical and Surgical Techniques
- Preoperative Planning.
Thorough patient evaluation is
essential to formulating a comprehensive risk factor-based case management
plan. This incorporates multiple
blood conservation measures in an optimized, integrated, and algorithmic
manner. A careful medical history,
physical exam, and judicious laboratory testing will identify anemic
conditions, clotting deficiencies or pre-existing complications (e.g.,
cardiopulmonary disease). This
includes careful management of the patient’s medications. Prophylactic treatment and
perioperative management is determined for each individual patient. Consultation with senior specialists
may be necessary.
- Prompt Surgery. The timely arrest of
bleeding by surgical repair or other means before blood levels fall to
extremely low levels is imperative.
Delayed action due to reliance on banked blood can result not only
on increased blood loss, but also higher morbidity and mortality. Performing complex operative procedures
in stages may minimize blood loss in some patients. In some trauma cases, emergency surgery
may be performed to control bleeding and contamination followed by
temporary packing of the wound and rapid closure to allow for adequate
resuscitation and other care.
Later, definitive surgery can be performed more safely. This ‘damage control’ approach can
avoid massive transfusions and the associated risks. It is vital to stop active bleeding
before restoring normal blood pressure.
Rapid restoration of normal blood pressure may inhibit clot
formation, disrupt existing clots, and accelerate hemorrhage.
- Meticulous Surgical Hemostasis. Meticulous surgical technique
conserves red cells and contributes to avoidance of allogeneic blood. This includes traumatic surgical
techniques, expeditious and precise dissection along avascular anatomical
planes, and meticulous occlusion and control of bleeding vessels
encountered in the operating field.
A dry surgical field provides better visibility, decreases tissue
handling, reduces exposure of medical personnel to blood, and reportedly
shorter operating times.
Pharmacologic and mechanical blood conservation procedures are
valuable adjuncts but cannot replace good surgical skills and appropriate
use of hemostatic surgical devices.
Preventive hemostasis is a fundamental aspect of blood conservation
- Mechanical Occlusion of Bleeding Vessels. A
technique of using hemostatic clips, clamps, or similar devices to
temporarily obstruct or close off blood vessels to minimize bleeding at
the surgical site. This technique
can be used to stop bleeding from small and large vessels. Vascular organs (e.g., liver, spleen)
can be temporarily isolated in this way to minimize blood loss.
- Arterial Embolization. Therapeutic
introduction of either mechanical or chemical agents into blood vessels to
occlude them. A catheter placed
into an artery is used to inject various embolic materials. In elective surgery, it may be used
preoperatively to limit blood loss from a surgical site (e.g., excision of
a tumor). In emergencies,
embolization can control active bleeding from a lacerated artery. This intervention avoids general
anesthesia and major surgery.
- Controlled Hypotension/Hypotensive Anesthesia. Intentional
and controlled lowering of blood pressure reduces bleeding by decreasing
pressure on injured blood vessels and causing less disruption of newly
formed clots. It may minimize
hemorrhage in orthopedic procedures, as well as during and after a wide
range of other types of surgery.
Hypertension must be avoided.
Mild hypotension is desirable as long as cardiac output and oxygen
delivery is adequate. Small volume
resuscitation (using volume expanders) has the beneficial effect of
decreasing ongoing blood loss by maintaining tissue perfusion without
normalizing blood pressure.
- Controlled Hyperthermia.
Intentional and controlled lowering of
an anemic patient’s body temperature in order to decrease metabolic
activity, heart rate, and oxygen consumption. Unless hypothermia is specifically indicated, maintenance of
normothermia is reported to minimize bleeding.
- Prompt Restoration of Normothermia. Prompt rewarming of patients after surgery minimizes bleeding
and reduces the risk of infection.
Coagulation proteins have been shown to be less effective at
categories of autologous techniques are (1) preoperative blood donation and
storage (see Preoperative Techniques), (2) intraoperative and postoperative
blood cell recovery (see Blood Recovery/Salvage Devices), and (3)
- Preoperative Autologous Blood Donation (PABD). Pre-donation and storage of a patient’s
own blood a few weeks before elective surgery for transfusion during or
after surgery, if it is required.
Many patients are reassured by the thought that they are using
their own blood, rather than receiving the blood of another person.
- Hemodilution. A technique whereby several units of blood are collected from a
patient immediately before surgery and replaced with a non-blood volume
expander. Despite this dilution,
the patient has enough red blood cells to carry oxygen throughout the body. Although bleeding during surgery
remains unchanged, any blood loss during the surgical procedure contains
fewer red cells because the patient’s blood has been diluted. (This shed blood can be recovered and
returned to the patient.) At the
conclusion of surgery, collected blood may be returned to the patient.
- Autologous Component
Sequestration. Similar to hemodilution, except that the blood collected from a
patient immediately before surgery (and replaced with a non-blood volume expander)
is separated into components (red cells, concentrated platelets, and
plasma). Red cells and plasma may
be returned to the patient or held until required. This technique decreases the total
plasma volume withheld from the patient compared to other platelet
sequestration techniques. The
sequestered platelets are fresh, autologous platelets, in a quantity
reported to have an effect equivalent to approximately 6 – 10 units of
allogeneic platelets. Furthermore,
the plasma content sequestered within the concentrated platelets contains
fresh autologous clotting factors in a quantity equivalent to 1 – 2 units
of FFP (fresh frozen plasma).