NeuroSurgery InfoNet

Setup

Introduction

Resuscitation

Tracheostomy

Arterial line

CVP line

Peripheral IV

Introduction

Room

Head trauma surgery room setup is relatively simple: The only essentials are the operating table, a high-pressure oxygen tank, suction portals, and lights. The OR table should be oriented such that anesthesia has access to the face, airway, and upper extremities and any lines elsewhere on the patient's body. Access to suction and proximity to illumination sources further determines the ultimate situation of the operating table. Depending on the craniotomy the scrub technician may want to situate himself at the head or the side of the patient which will also affect the positioning of the OR table.

Anesthesia

Fluids should be administered sufficient to maintain a normovolemic central venous pressure (CVP) and cardiac output (CO). Beyond this fluids should be administered sparingly so as not to contribute to evolving cerebral edema. A maintenance IV rate calculated according to the formula of 5cc/kg/hr for the first ten kilograms body weight, then 2cc/kg/hr for the next ten kilograms, then 1cc/kg/hr for every kilogram of body weight.

The optimal IV solution has not been found or does not exist. It remains unknown. Normo- or hyper-osmolar solutions may contribute less to cerebral edema than do hypo-osmolar so the former are probably preferable to the latter in resuscitation of head injured patients suspected of harboring expanding intracranial hematomas.

Blood should be available for transfusion in every patient undergoing a head trauma craniotomy.

TABLE: Anesthetic agents used in head trauma operations

Anesthetic agents can be divided into the following categories: 1. Analgesics - medications that reduce nociceptive transmission, reception, and processing, 2. Opiates - derivatives of opium including morphine, codeine, demerol, and ketamine. Do not reduce perception of pain but patient's affective emotional reaction to it, 3. Benzodiazepines - medications such as diazepam (Valium), midazolam (Versed) that are hypnotic and amnesic, 4. Inhalational agents - some raise (Halothane), others reduce (Enflurane) or have no effect on (Isoflurance ) intracranial pressure.

FIGURE: Operating room

Whenever possible the table should be oriented with the feet of the patient facing anesthesia to allow the surgeons optimal access to the sides and top of the head.

Variables in the setup of the table include its orientation in space with respect to the doors and other major equipment in the room as well as the flexion at each of its head, torso, and foot segments. The uppermost, head segment of the OR table top should be elevated to maintain the patient's head elevated to 30 degrees with respect to the floor.

FIGURE: Flexion of table A

FIGURE: Flexion of table B

The lights should be directed onto the surgical field at the anticipated site of maximal activity. They should not be so close to the field that they are liable to be contaminated by heads or extremities.

B. Personnel

Personnel in the head trauma OR in addition to the surgeon include a circulator who remains non-sterile and is available to hand instruments onto and take them off of the operative field, a scrub technician who lays out the instruments on a sterile tray and passes them to the surgeon during the procedure, and an individual administering anesthesia

C. Anesthesia

While the surgeon will not induce, manage, or terminate anesthesia, the effects that anesthesia can have on the intra- and post-operative surgical course are sufficiently great that the surgeon must make sure that anesthesia for a head trauma surgery is set up to maintain cerebral perfusion and oxygenation without compromising measures for control of intracranial pressure. The surgeon may need to teach the person administering anesthesia how to read the ICP monitor as well as how to open and close the stopcock in the ventricular drainage system.

D. Patient

The sequence of procedures necessary for setting the patient up for a head trauma operation begins with the transfer of the patient from the emergency room gurney or intensive care unit bed to the operative table. Next the patient must be positioned. Finally he is "prepped and draped".

1. Transfer

The awake and cooperative patient should be assisted in moving onto or off of the operating table. The patient with altered mental status or in coma requires total assistance through a coordinated team effort with the head trauma surgeon in charge.

Because changes in position are so difficult once surgery is underway, the patient should be transferred such that he ends up optimally situated on the table with respect to its rostro-caudal and lateral extents. Make sure the brakes on the gurney and OR table are locked. Two people push or roll the patient and two receive. If only four people are available: one on each side and one each at the head and legs.

The patient paralyzed under general anesthesia has no protective mechanisms to stabilize the neck and therefore is vulnerable to injury at this location. During the positioning activities of the setup, someone is designated to manage the position of the head in space with respect to the rest of the body to prevent cervical injury. Maintenance of a physiologic and biomechanically stable configuration of the cervical skeleton minimizes the chance of dislocations, and other mishaps when moving or transferring the comatose head injured patient.

All lines potentially tethering the patient during the transfer must be identified and freed to give adequate slack before moving the patient. The transfer should be deliberate yet smooth enough such that none of the vital anesthesia infusion or monitoring lines are dislodged.

2. Positioning

The optimal patient position depends on the craniotomy required by the pathology, but patient physiologic factors, both premorbid and injury-related, must also be taken into consideration. In order to select among the various possible patient positions the surgeon needs familiarity with the exposures possible with each position.

Physiologic considerations that must be addressed in setting up the patient position include: venous pooling in lower extremities (decreased cerebral perfusion) and increased intrathoracic pressure (decreased cerebral venous outflow). Head elevated above heart level predisposes to air embolism.

Increased ICP: keep the head of bed 30 degrees. In the supine position the legs are lower than the trunk. The heart should never be above the level of the head as this creates a pressure gradient favoring blood flow into, and not drainage from, the intracranial space with potential further elevation of the pressure therein.

Hypovolemic shock: extremities above heart, head below heart (may be necessary in spite of ICP control considerations).

Soft tissue pressure injuries (can result at heels and buttock during prolonged procedure): Padding of extremities.

The setup of the cardinal positions of head trauma surgery: supine, lateral, and prone (and their modifications) is the coordinated arrangement on the OR table of the patient's head, body, and extremities.

FIGURE: OR table segments (ortablesegments.gif)

3. Supine

3.1) Table

a) The table should be flexed for the supine position. The upper segment should be set to 30 degrees with respect to the floor. The middle segment should be elevated to 30 degrees with respect to the floor, the foot segment is at 30 degrees (parallel to the head segement..

3.2) Head

When set up in the supine position the neck, and chest is unencumbered and unattached which increases the possibilities for head positioning.

The head can be placed comfortably on a donut headrest or the more complicated, cumbersome, and potentially hazardous horseshoe headrest with the face forward, or rotated. If the horseshoe is used the patient's shoulders should be advanced all the way to the top of the table and the neck slightly extended. Pins offer increased stability but no better exposure than either horseshoe or donut.

FIGURE: Supine rotated anterior torso (supinerotatedanteriortorso.gif)

3.3) Body

In setting the patient up supine, pads are placed under the feet to prevent pressure sores, and bilateral leg squeezers around the legs to prevent formation of deep vein thromboses.

FIGURE Setup OR table supine (supinetableflexbody.gif)

TABLE: Setup of positions

sdf	From above	From below
Donut	FIGURE: Head on donut rotated supine view from above (donutsupinerotatedabove.gif)	FIGURE: Head on donut rotated supine view from below (donutsupinerotatedbelow.gif)
Horseshoe	FIGURE: Horesehoe supine face up vertex view (horseshoesupinerotateabove.gif)	FIGURE: Horseshoe supine face up from below (horseshoesupinerotatedbelow.gif)
Pins	FIGURE: Head in pins supine face up from above (pinsfaceupabove.gif)	FIGURE: Head in pins supine face up from below (pinsfaceupbelow.gif)

3.4) Extremities

The setup of the extremities is straightforward with the patient supine: arms alongside body, tucked.

4. Lateral

Setting up the lateral position is more complicated than the supine. It requires positioning the body and head interdependently.

The lateral position setup is simplest if divided into three stages: 1. Placement of pins, 2. Body positioning, 3. Head positioning and fixation.

4.1) Table

The table should be set up for the lateral position.

4.2) Head

With the assistant holding the head with two hands (one across the brow the other suboccipital) the surgeon removes the head support attachement of the OR table sets it aside. The three point contact fixation pins are oriented with the two on the rotating side arm equidistant from the inion. The single pin is placed laterally on the forehead.

The pins should be tightened into the skull ___ .

The surgeon then takes hold of the head holder frame while the assistant swings the head holding arm of the table attachment up to meet the frame. The frame is then screw fixed to the head holding table attachment.

4.3) Body

The body is positioned next. The patient is rotated and moved across the table such that the side contralateral to the planned craniotomy is dependent.

A kidney rest attachment supports the back and is placed in the lumbar region behind the iliac crests. In conjunction with the pins and the shoulder bolster, this keeps the patient turned laterally. There is a bolster under the dependent shoulder.

(lateraltorsoback.gif)

FIGURE:FIGURE: Kidney rest attachment supporting back lateral position

4.4) Extremities

When placing the patient in the lateral position the metal frame of the "airplane" attachment supports the nondependent arm in extension from the body allowing the surgeon to position the patient's arm forward and out of the field

FIGURE: Nondependent arm supported by "airplane" (lateraltorsofront.gif)

A pillow is placed both under the dependent leg and between that and the non-dependent leg. The position of the legs is then adjusted: The lower is maximally flexed at the hip and bent at the knee. The free (upper) leg is then laid on a pillow placed between the legs. Foam heel protectors are used to prevent pressure necrosis during several hours of surgery.

FIGURE:FIGURE: Legs in lateral position

FIGURE: Lateral body (lateralbodybelow.gif)

4.5) Head Fixation

Once the patient's body is positioned the head with the attached pin fixation head holder is positioned and fixed to the table. Because the head is so much narrower than the shoulders, it must be suspended in space with the patient's body lateral and a dependent side. A wide range of rotation is possible by changing the position of the C-clamp head holder.

FIGURE: Head in pins supine forward (pinssupineforward.gif)

FIGURE: Head in pins supine rotated (pinssupinerotated.gif)


The external jugular can frequently be seen and is an indicator t

5. Three-quarter lateral

5.1) Table

The table should be setup with its head segment at ___. The foot segment can be dropped ___.

5.2) Head

The three-quarter lateral position is a modification of the lateral. Like the lateral it requires placing the head in the 3 contact point pin head holder.

As in the setup of the lateral position setup of the three quarter lateral requires maintenance of a physiologically and biomechanically acceptable alignment of the cervical vertebral column. The head is rotated (flexed) forward, in the coronal plane. The head is rotated towards the dependent pins. In the axial plane the head is rotated in the direction of the dependent pins, that is, towards the floor.

The patient's head can be rotated even further away from the surgeon to give better posterior fossa access.

FIGURE:Three quarter lateral body in pins with sling above oblique

FIGURE:Three quarter lateral body in pins with sling above

FIGURE:Three quarter lateral torso front

5.3) Body

It may be necessary to use a kidney rest and or inflatable bean bag to bolster the patient, to secure them in the position. The arm in which anesthesia has its major venous access line and arterial monitoring device should be stretched out on an arm board. An airplane attachment may be necessary to support the forward extended arm in a patient in the lateral position.

5.4) Extremities

Legs in the three-quarter lateral position should be dependent, that is, lower than the level of the heart. The patient is bent at both the knee and the hip and a pillow is placed between the dependent and nondependent leg.

Placing strong tape on the nondependent shoulder and stretched forward and attached to the operating table to pull the patient's torso forward toward the airplane attachment (discussed below) which supports this arm extended in front of the patient. The shoulder of the non-dependent arm is taped and pulled downward (to move it out of the surgeon's way). The dependent (lower) arm is bolstered with an axillary roll that protects from brachial plexus injury. The airplane attachment supports the nondependent arm when the patient is in the lateral position. Potential access to posterior fossa as well as occipital.

To rotate the patient further toward prone, a sling can be used to suspend the dependent arm. The dependent arm, rather than lying extended in front of the patient where it may get in the surgeon's way, can also be hung over the top of the table in a sling. This sling arrangement is possible only because with the head in pins. The upper part of the patients body can ride such that the shoulders hang over the head of the table.

Prone

Prone is the easiest to set up of posterior head access body orientations. But the range of possible variations in head position (and thus possible exposures) with the body prone position are few.

The patient's face can be straight ahead, looking towards the floor if it is placed on a horseshoe headrest in which case the endotracheal tube must pass through the horseshoe attachment to reach either the mouth or nose. Significant pressure can result on the malar eminences resulting in pressure sores.

One way to avoid facial pressure sores with the patient face down prone is to put the head in pins (as is commonly done for posterior cervical operations).

Head If face down on the donut or horseshoe is for any reason impossible, almost as good posterior exposure of the head results with the extreme three quarter lateral variant of the lateral orientation as described above.

The face can be placed on a donut, but must then be turned to the side for endotracheal tube access. Not much can be done in the way of rotation of either the body or the head in the prone position. The only variation is whether the patient's face looks down through a horseshoe headrest or off to the side on a donut. Surgical access will be slightly different depending on the positioning of the face.

GALLERY: POSITIONS

Both the donut and the horseshoe allow for the head to be lifted and rotated during the case.

The body will not slide down when prone and therefore flexion of the table is not necessary. Bolsters are placed vertically on both sides to permit respiratory excursions to support laterally while allowing downward movement of the thorax during the respiratory cycle (i.e.: they elevate the patient's chest and abdomen several inches off of the table to permit respiratory excursions).

When positioning the body and trunk prone ventilatory excursions must remain adequate with no excessive increases in the resistance to mechanical ventilation. Intrathoracic venous pressure should be kept down to minimize the effect on cranial venous drainage. A chest bolster maintains a distance between the thoracic cage and the top of the OR table.

In positioning the patient prone pillows are placed under the legs (tibial aspect) to prevent sliding down but more important, pressure sores in this location. Anti-thrombogenic leg squeezers are used in all craniotomies, whether prone, supine, or lateral. The arms are tucked with sheets.


TABLE Setup of positions for head trauma craniotomy

Security

Patient safety is no less a consideration in setting up a head trauma craniotomy than in setting up any surgical procedure. The surgeon should be familiar with the purposeful and accurate placement of bolsters, arm rests, and pillows to maximize patient physiology while minimizing the risk of soft tissue (skin, muscle, nerve) pressure injury.


Head shave

If possible to avoid dispersing dander and dirt from hair into the air in the operating room the head should be shaved in the ICU or surgical holding area prior to transfer into the OR.

Head shaving is done in two stages. First the hair is cut to a uniform few-millimeter length with an electric clipper. The technique is straightforward: if the patient is comatose or otherwise uncooperative the head is held from behind off the bed. The comb-blade is then advanced from forward back in multiple swathes until all of the long hair has been cut uniformly short.

FIGURE: Shaving hair (shavinghair.gif)

The hair should be shaved as short as possible but if the razor is too vigorously applied to the surface of the skin cuts result which are unsightly potential portals of scalp infection. Even small amounts of wet blood on the skin surface interfere with proper application of sterile sticky drapes.

9. Prep and drape

The prep assistant washes the skin first with an iodine-based detergent solution. The detergent component is hydrophobic and removes particles held to the oils in the skin and hair. The iodine oxidizes and destroys bacterial cell membranes killing saprophytic and much rarer pathogenic bacteria resident on the patient's skin. The betadine detergent is then rinsed off with sterile plain water. Finally the skin is "painted" with iodine solution at the operative site and for several centimeters beyond.

The action of both scrubbing (with soap detergent) and painting (with iodine solution) is a circular one working from the inside out, the origin of the cleaning at the center of the surgical field such that dirt and pathogens are always being swept from central to peripheral with respect to the focus of the operative procedure. Iodine works through oxidation and the solution must dry (3-5 minutes) prior to the next step in prepping and draping for maximal bacteriocidal effect.

Adhesive can be sprayed around the perimeter of the desired field to help with secure apposition the stick sterile drape to the skin. One kind of an adhesive spray is a hydroxy-vinyl chloride acetate copolymer with a glycolate plasticizer in a gaseous propellant. This spray should be sprayed holding the sprayer approximately 18" from the surface of the skin. The spray, which is pink colored, should be sprayed just until a pinkish hue is observed. While helping stick the adhesive drape to the skin, the necessity for sticky spray is dubious. Dust, bacteria, or other particulate contaminants stick to the skin of the operative filed.

Drapes set off and protect the prepped, sterile surgical field. Those made from cloth are reusable, re-sterilizable, and relatively sturdy. Drapes with an attached impermeable fluid-collecting apron are useful in trauma cases where there can be significant blood loss and irrigation. Holders of instruments come with some devices out of the manufacturers package. Makeshift pouches and pockets can be created with sterile towels attached to the drapes with towel clamps.

Sterile towels are laid to demarcate the perimeter of the craniotomy. These towels will stick to the skin where the adhesive spray has been sprayed. If there is any concern about movement of the towels, they can be secured in place with an occasional staple between the edge of the towel and the skin. The corners where towels intersect can be approximated and held in place with towel clips, which are then placed under the towels.

Cloth surgical drapes are reusable, re-sterilizable and are relatively sturdy. Drapes with an attached fluid collecting apron are helpful for head trauma cases where there can be significant blood loss and irrigation. The first drape is laid from the patient's neck down covering the body. A second drape is used around the head.

The third drape allows, by way of a hole or split in it, for circumferentiation of a field. A fourth drape places a physical barrier between the activities of anesthetist and surgeon.

Pouches on the operative field are placed in locations where they are out of the immediate working area but readily accessible. The placement of the electrical cords is important because they can become obstructions and are the source of tangling among different instruments during the case. Both monopolar and bipolar should be on the surgeon's right. Suction should be placed to the surgeon's left or non-dominant side.

Instruments attached to cords are fixed at least twice: to the power source and to the operative field. The surgeon must allow an adequate amount of slack of cord to maneuver at the location in the operative field farthest from the site of fixation to the drape.

10. Marking

For any straight incision longer than 10 cm or one that is curved and requires placement of scalp clips the final length will result from a series of connected shorter incisions. The length of these shorter incisions depends on factors: length of skin edge along which surgeon and assistant finger pressure can control bleeding, shape of the incision, ability to manipulate the extent of the edge of scalp that will be exposed once the skin incision has been extended down through the SCALP layers to the periosteum. For a curved, "S"-shaped, or "question mark" type scalp flap, the segments of skin incision should be approximately 8 to 10 cm.

Marking of the skin is a preliminary commitment to a course of incision and scalp division.

The frontalis branch of the facial nerve emerges from the stylomastoid foramen and runs forward into the face. One of its branches swings up in front of the ear where it is susceptible to transection by an incision that is placed too far anterior with respect to the tragus of the ear. To avoid the cosmetically unacceptable inability to wrinkle the ipsilateral face, the skin incision should be drawn and cut no more than one finger breadth anterior to the tragus. It is preferable for a small segment of incision to be visible as a scar behind the hairline anterior to the ear than for the patient to have a disfiguring iatrogenic neurologic deficit.

The superficial temporal artery lies anterior to the ear but is frequently not palpable in this location and its location is somewhat variable, such that often in making a scalp flap, which extends to the zygoma root, transection of the artery cannot be avoided. The superficial artery lies in the space between the subcutaneous tissue and the galea aponeurotica.

Once the skin has been scrubbed, painted and blotted dry, the surgeon marks the skin incision with a sterile soft-tipped, water-based ink pen.

Stretching and folding of the scalp during the procedure will inevitably cause swelling and distortion such that, when closing the skin, corresponding points along the edges will not be correctly approximated accurately unless cross hatches are made along the incision line. The cross line should be 1-2 cm long, perpendicular to and centered on the projected incision line. Skin edge reapproximation guide lines should be no closer than one every 8-10 cm and of varied length to avoid confusion as to which corresponds to which at the time of closure.

Alternatively, and because water-based ink can be washed or rubbed off in the course of the operation, a sharp-pointed object, such as the back of a 15-blade, or even the tip of a 15-guage needle, can be used to incise dermis to the depth which results in slight bleeding to delineate the course of the skin incision and the extent of the scalp flap edge.

Skin and bone landmarks (visible or palpable) can help in drawing out the incision. Short straight lines of varying length placed at regular intervals of 10 to 15 cm, perpendicular to, and bisected by, the line for the skin incision, are convenient visual aids to accurate and correspondent reapproximation of skin edges.

Coagulation or ligation of the superficial temporal artery probably contributes to temporalis muscle atrophy commonly observed following temporal craniotomies. The alternative to sacrifice of the superficial temporal artery in the setting of head trauma would be to fashion an osteoplastic flap to preserve the integrity of the superficial artery and temporalis muscle, but if the scalp flap is to be reflected as a unit with all layers, the strategy should be to anticipate transecting the artery and to deal with the resultant hemorrhage expectantly.

Pouches should be placed on the operative field in locations where they are out of the immediate working area but readily accessible. The placement of the electrical cords is important because they can become tethers and obstructions and interferences and cause tangling among different instruments during the case. It is advisable to take a few minutes while setting up to determine the optimum arrangement for all wires, cords and tubes.

Instruments attached to cords are fixed at least twice: 1. to the power source and 2. to the drapes somewhere in the operative field. The surgeon must allow an adequate amount of slack of cord to maneuver at the location in the operative field farthest from the site of fixation to the drapes.

A portable stand can be brought in on either side of the surgeons but is most commonly located to their right.

The right-handed surgeon should position himself standing to the left of his assistant.

Many surgeons prefer to operate standing. Standing is the position of greatest mobility. Fewer movements are necessary to translate the body from one to another location from the standing than from the sitting position. Sitting however is more comfortable. There is less fatigue on the back, legs, neck, and upper arms. When large distances in the operating field must be covered quickly standing is best. This would include during all steps of opening. And during closure.

Indications for sitting: 1. attention is to be focused on circumscribed portion of the field for 10 minutes or more 2. field is too low with the respect to the surgeon in spite of raising and planing the table. (Bending over by the surgeon should be kept to a minimum to avoid accelerated fatiguing and injury.)