Under careful aseptic precautions, the IJV on the side to be cannulated is typically punctured under ultrasound guidance at the level of the apex of the triangle formed in the neck by the two heads of the sternocleidomastoid muscle and the clavicle. The Trendelenburg position, often used for central venous cannulation for improved ultrasonographic visualization of the IJV, may not be an option in patients with poor intracranial compliance. The Seldinger technique can be used to thread the jugular bulb catheter over a guide wire. An introducer sheath (5–6 French size) is first inserted through which an oximetric catheter (4.5–5 French) is advanced in a cephalad direction until a resistance is felt (15–20 cm in most adults), which generally coincides with approaching the superior jugular bulb where there is a slight bend in the vessel lumen just below the jugular foramen below the base of the skull. The catheter is then pulled back half a centimeter. The cannulation technique is similar to that for central venous catheterization except that the needle, guide wire, and catheter are advanced in a cephalad direction (Fig. 14.3). We routinely use a 16 G, 5.25-in. long venous cannula for intraoperative jugular venous oximetry [4, 6]. We usually insert the catheter to a distance equal to that measured from the point of insertion to the level of the mastoid process until resistance is met. This technique is helpful in adult as well as pediatric patients [4].

The final position of the cathete r in the jugular bulb should be confirmed by a lateral X-ray of the skull documenting the catheter tip at the level of, and just medial to, the mastoid process. It has been suggested that radiographic assessment of jugular venous catheters is best performed using an overpenetrated Stenvers view (with rotation of the head 15°–20° away from the side of the SjvO₂ catheter) and a companion over-penetrated lateral radiograph of the neck. Alternatively, on an anteroposterior (AP) view of the skull, a correctly positioned catheter should lie cranial to the line extending from the atlantoaxial joint and below the inferior orbital margin [16]. Accurate positioning of the catheter tip is essential for dependable SjvO₂ data. Even when the catheter is placed in a perfect position, it is not unusual for the catheter tip to migrate leading to falsely high SjvO₂ values [10]. Hence, the catheter may need readjustment periodically. The presence of an introducer sheath facilitates such adjustments.

It is recommended that the jugular bulb on the side of dominant venous drainage be cannulated. Different suggested approaches to identify the dominant IJV are:

Jugular oximetry can be performed either by intermittent sampling of blood or by fiberoptic technology using spectrophotometric catheters that allow continuous displays of SjvO₂ values. The underlying principle is based on the differential absorption of light at different wavelengths by oxyhemoglobin and reduced hemoglobin. The Baxter-Edwards system (Edslab Sat II, Baxter Edwards Critical Care Division, Irvine, CA) uses two wavelengths of light for reflectance spectrophotometry and is calibrated against a sample of the patient’s blood. The Abbott system (Opticath Oximetrix, Abbott Critical Care System, Abbott Park, IL) uses three wavelengths of light and may be calibrated in vivo (against the patient’s blood) or in vitro (built-in calibration).

A prospective protocol comparing 195 blood gas measurements with simultaneously recorded continuous bedside oximetric monitor values for 31 ICU patients with TBI undergoing jugular venous oxygenation monitoring for an average of 3.4 days reported acceptable correlation between the in vivo monitor (Baxter-Edwards, Santa Ana, CA) and in vitro co-oximetry [19]. Although the sensitivity of the continuous oximetry was somewhat low (45–50 %), the specificity was 98–100 %, indicating that it is less of a concern that patients may be misdiagnosed as having desaturations resulting in unnecessary interventions [19]. Nonetheless, the investigators recommended that suspected jugular bulb desaturation should be verified before taking therapeutic actions [19]. The fiberoptic catheter has also been noted to provide accurate measures of SjvO₂ during neurosurgical procedures in a series of 12 patients with 111 readings ranging from 42 to 95 % [20]. However, in another ICU study of patients with TBI, there was a poor correlation for the first in vivo calibration although subsequently, a close correlation between jugular bulb catheter and oximetry values was demonstrated during episodes of jugular bulb oxygen desaturation resulting from a variety of causes including hypocapnia, hypoperfusion, and intracranial hypertension [21]. These investigators also recommended validation with a laboratory oximeter prior to continuous jugular bulb oximetry [21]. Subsequent to calibration with a laboratory co-oximeter, the Edslab catheter (Baxter Healthcare Corporation, Irvine, CA, USA) was also found to provide SjvO₂ values that correlated well with co-oximetry with no appreciable drift and negligible bias [22]. Interestingly, the measurement of SjvO₂ by the fiberoptic method compared poorly with bench oximetry during cardiopulmonary bypass (CPB) although there was good agreement between the two methods in the 18 h postoperatively [23]. There were wide limits of agreements (mean difference ± 2 SD) between the two methods during operation (−20.29 to 18.05 %), whereas after operation the limits of agreement were far narrower (−6.39 and 7.45 %) [23]. When indwelling catheters are used for continuous SjvO₂ monitoring for several days and/or hemoglobin level is expected to change, it is customary to draw blood samples from the jugular bulb to calibrate the oximeteric catheter at least once daily.

Below the jugular bulb, the IJV receives facial and retromandibular venous blood, causing extracranial admixture. Consequently, faster rates of sampling increase the admixture from the extracranial veins, giving falsely elevated SjvO₂ values. In mechanically ventilated patients undergoing neurosurgical procedures, Matta and Lam [24] found that sampling at rates faster than 2 mL/min resulted in significantly higher SjvO₂ values. Hence, to avoid overestimation of SjvO₂, blood samples should be drawn slowly, at approximately 2 mL/min, particularly when the patient is hyperventilated or CBF is otherwise reduced pharmacologically (e.g., during barbiturate therapy) [24]. Importantly, there are no data to prove that the rate of 2 mL/min is free of extracranial blood contamination. Although sampling rates slower than 2 mL/min may further improve accuracy, they may not be practical and may not allow rapid assessment of changes.

Potential complications are associated with either (1) insertion of the catheters (carotid artery puncture, injury to nerves, injury to lymphatic duct on the left side, pneumothorax) or (2) the presence of an indwelling catheter (infection, thrombosis). In a series of 80 patients, Jakobsen and Enevoldsen [25] had an accidental carotid artery puncture with the Seldinger technique in one patient. Subsequently, Matta et al. [6], in a series of placements of retrograde jugular venous bulb catheters in 100 consecutive anesthetized patients undergoing neurosurgical procedures, reported carotid artery punctures in two patients that were controlled by firm pressure. We have reported our experience of placing jugular bulb catheters in anesthetized pediatric patients and noted no arterial punctures [8]. The use of ultrasound is likely to further reduce the risk of arterial puncture, especially with experienced providers. Serious consequences involving the development of a hematoma that may follow the insertion of a 5–6 French introducer can be avoided, if the smaller catheter (#18g) is always connected to a pressure transducer to ascertain (from the waveform) the presence of the catheter in the vein prior to insertion of the introducer. In a rare case, inadvertent penetration of the posterior wall of the jugular vein during cannulation has been reported, leading to the placement of the catheter tip in the subarachnoid space [26]. Another rare case of unintentional cannulation of the anterior venous plexus of the cervical epidural space during retrograde catheterization of the jugular vein has also been reported [27]. Other complications such as Horner’s syndrome and injuries to the phrenic or recurrent laryngeal nerve may also occur.

The ICP can be increased by obstruction of cerebral venous drainage. Although concerns are sometimes raised about the possible obstruction of cerebral venous outflow by jugular bulb catheters, the size of the catheter used for SjvO₂ is very small compared with the size of the vein being cannulated. In fact, Goetting and Preston [28] found no evidence that jugular venous catheterization with indwelling catheters has any significant effect on ICP [28]. Venous thrombosis associated with SjvO₂ monitoring has not been reported but could have serious consequences. The risk can be minimized by using the smallest catheter and maintaining patency of the catheter. Infection and sepsis is a known complication with all types of indwelling catheters. Stocchetti et al. [15] reported catheter-induced sepsis in 1.8 % of 45 patients. Strict aseptic technique during insertion and maintenance of catheters is critical.

Absolute contraindications include venous thrombosis. Relative contraindications include hypercoagulable states, coagulopathy, the presence of tracheostomy (due to risk of infection), and unstable cervical spine conditions providing suboptimal patient positioning for placement of the catheter.