Jugular Bulb Venous Oxygen Saturation Research Articles

Cerebral Oxygen Saturation Measured by Near-infrared Spectroscopy and Jugular Venous Bulb Oxygen Saturation during Arthroscopic Shoulder Surgery in Beach Chair Position under Sevoflurane-Nitrous Oxide or Propofol-Remifentanil Anesthesia

We examined the effects of different anesthetics on cerebral oxygenation and systemic hemodynamics in patients undergoing surgery in beach chair position (BCP). Jugular venous bulb oxygen saturation (SjvO2) and regional cerebral tissue oxygen saturation (SctO2) were determined while patients were placed from the supine to BCP. Whether SctO2 and SjvO2 are interchangeable in assessing the cerebral oxygenation was also examined. Forty patients undergoing shoulder surgery in BCP were randomly assigned to receive sevoflurane-nitrous oxide (S/N) or propofol-remifentanil (P/R) anesthesia. Four patients taking angiotensin II receptor antagonists were excluded post hoc. Mean arterial pressure and heart rate, as well as SjvO2 and SctO2, were measured before (postinduction baseline in supine position) and after BCP. Mean arterial pressure decreased by BCP in both groups. It was, however, significantly higher in S/N (n = 19) than in P/R group (n = 17) at 7 to 8 min after the positioning. SjvO2 also significantly decreased after BCP in both groups, the magnitude of which was lower in S/N than in P/R group (11 ± 10% vs. 23 ± 9%, P = 0.0006). The incidences of SjvO2 <50% and mean arterial pressure less than 50 mmHg were lower in S/N group, but SctO2and the incidence of cerebral desaturation (more than 20% decrease from baseline) did not significantly differ between the groups. SctO2 and SjvO2 were only weakly correlated (β = 0.218, r2 = 0.133). Bland-Altman analysis showed a mean difference of -7.2% with 95% limit of agreement between -38.2% and 23.8%. The margin of safety against impaired cerebral oxygenation is greater and SjvO2 is more preserved with S/N than with P/R anesthesia. SctO2 may not be reliable in detecting a low SjvO2 during the surgery in BCP.

The effect of hypercapnia and hypertension on cerebral oxygen balance during one-lung ventilation for lung surgery during propofol anesthesia

Study objective To investigate whether jugular bulb venous oxygen saturation (SjO 2) values increased with induced hypercapnia or induced hypertension during propofol-based anesthesia for one-lung ventilation (OLV). Design Prospective clinical study. Setting Operating room at University hospital. Participants 15 adult patients scheduled for elective thoracic procedures in the lateral position. Interventions General anesthesia was maintained with propofol combined with epidural anesthesia. During OLV, hypercapnia (PaCO 2 = 50 mmHg) and hypertension (20% increase in mean arterial pressure) were applied. Measurements SjO2 values were measured. Main results With hypercapnia, SjO 2 values increased 30 ± 18% (from 54.3 ± 8.8% to 69.3 ± 6.3%). With hypertension, SjO 2 values were increased by 9 ± 18% (from 54.4 ± 9.0% to 58.5 ± 8.8%). These changes were significantly different. No significant differences regarding SaO 2 were observed during OLV in the experimental period. Conclusion Hypercapnia, not hypertension, significantly improved cerebral oxygen balance without observed side effects during propofol anesthesia.

Volatile induction/maintenance of anaesthesia with sevoflurane increases jugular venous oxygen saturation and lumbar cerebrospinal fluid pressure in patients undergoing craniotomy

Sevoflurane is a widely used volatile agent in neuroanaesthesia, and its nonirritant properties on the respiratory tract make sevoflurane suitable for volatile induction/maintenance of anaesthesia (VIMA). In the current trial, we investigate the effects of sevoflurane VIMA on lumbar cerebral fluid pressure (LCSFP) and jugular venous oxygen partial pressure in patients undergoing craniotomy for supratentorial intracranial surgery under bispectral index monitoring, determine jugular bulb venous oxygen saturation (SjvO2) and calculate cerebral perfusion pressure (CPP), arteriojugular venous oxygen content difference and cerebral oxygen extraction rate (COER) at different time points during the operation. Moreover, we compare these with total intravenous anaesthesia (TIVA) in patients receiving remifentanil and propofol continuous infusion. Twenty-six adult patients undergoing elective craniotomy were randomly allocated to either remifentanil-propofol (group TIVA) or sevoflurane (group VIMA). Mean arterial blood pressure, heart rate, LCSFP, CPP, SjvO2, arteriojugular venous oxygen content difference and COER were compared in the two groups at different time points under bispectral monitoring. Heart rate, mean arterial blood pressure, saturation of peripheral oxygen, BIS value and LCSFP were recorded at the time points including intubation (Tintub), 5 min (T5'int) and 15 min (T15'int) after intubation, the beginning of surgery (Tsurg), 5 min (T5m), 0.5 h (T0.5h), 1 h (T1h), 1.5 h (T1.5h), 2 h (T2h) and 2.5 h (T2.5h) after incision, the end of surgery (Tend), extubation (Textub) and 30 min (T30'end) after surgery. Arterial blood gas and jugular venous bulb blood gas analysis were performed at the time points of T0, T5'int, T5m, T1h, T2h, Tend, 15 min after operation (T15'end) and T30'end. LCSFP was increased above baseline levels in group VIMA and decreased in group TIVA from Tintub to T5m, and decreased to similar levels from T0.5h to T30'end in both groups. Mean arterial blood pressure was decreased to similar levels from T0.5h to Tend and returned to baseline levels at T30'end in both groups, and was significantly higher in group VIMA than in group TIVA at T5'int, T15'int, Tsurg and T5m. CPP was decreased to similar levels between the groups from T0.5h to Tend and returned to baseline levels at T30'end in both groups, and was significantly higher at Tintub, T5'int and T15'int in group VIMA than in group TIVA. Jugular venous oxygen partial pressure and SjvO2 were increased above baseline level from T5'int to T30'end in group VIMA, and decreased from T5'int to Tend, and returned to baseline level at T30'end in group TIVA. Arteriojugular venous oxygen content difference and COER were decreased from T5'int to T30'end in group VIMA, and increased above the baseline level from T5'int to Tend, and returned to the baseline level at T30'end in group TIVA. Sevoflurane VIMA increases SjvO2, lumbar CSF pressure and CPP, and decreases COER, which suggested that VIMA could be a better choice for patients with the risk of cerebral hypoperfusion or insufficient oxygen delivery. Propofol-based TIVA is associated with decreased SjvO2, LCSFP and CPP, and increased COER, and it might be suitable for patients with increased intracranial pressure.

Comparison between Regional Cerebral Oxygen Saturation and Jugular Bulb Venous Oxygen Saturation in Patients Undergoing OPCAB Surgery

Background: Hypoperfusion during manipulation of the heart in off-pump coronary artery bypass (OPCAB) surgery may lead to postoperative neurological complications. Therefore, it will be necessary to monitor cerebral function during OPCAB surgery. In this study, we compared regional cerebral oxygenation (rSO2) by near-infrared spectroscopy (NIRS) with jugular bulb venous oxygen saturation (SjvO2) and assessed whether rSO2 measured by NIRS could be an alternative method of SjvO2 during OPCAB surgery. Methods: A total of 20 patients who underwent OPCAB surgery were studied. A fiberoptic catheter was placed in the right jugular bulb to measure SjvO2 while a cerebral oximeter based on NIRS, INVOS 5100B was used to monitor rSO2. Radial arterial and jugular bulb blood samples were drawn simultaneously from baseline every hour during operation. The values of rSO2 were compared with SjvO2 values. Results: For all data points (n = 78) for all patients combined, rSO2 values were significantly correlated with SjvO2 values (r = 0.513, P ＜ 0.0001). There were significant correlations between arterial carbon dioxide and values of SjvO2 (r = 0.393, P = 0.0002) and rSO2 (r = 0.432, P ＜ 0.0001). Conclusions: We concluded that NIRS correlates with SjvO2 in this patient population. These findings suggest that near-infrared spectroscopy may be useful in assessing cerebral oxygenation during OPCAB surgery. (Korean J Anesthesiol 2008; 54: 47～52)

Splanchnic ischemia and gut permeability after acute brain injury secondary to intracranial hemorrhage

Splanchnic ischemia (SI) and increased gut permeability (GP) have been described in acute brain injury (ABI), although their incidence and relation to the type and severity of injury are uncertain. The aim of this study was to evaluate the incidence of both abnormalities in a series of patients with severe ABI secondary to intracranial hemorrhage (ICH) managed with a resuscitation protocol pursuing adequate cerebral and systemic hemodynamics. Eight patients with severe ABI secondary to ICH were admitted to the ICU and were mechanically ventilated and monitored with intracranial pressure measurement, jugular bulb venous oxygen saturation, arterial lactate concentration and gastric tonometry. All patients were managed actively to maintain adequate blood and cerebral perfusion pressures with a protocol based on aggressive fluid resuscitation prior to vasoactive drugs administration. GP was assessed using the lactulose/mannitol test (LMT). Values were recorded during the first 7 days of hospital stay. Arterial lactate concentration was within the normal range (1.9 +/- 0.5 mmol/l) in all patients. Upon admission, the mean pCO(2) gap was 8.2 +/- 4.3 mmHg (1.09 +/- 0.57 kPa) with an intramucosal pH of 7.4 +/- 0.1. All patients had an abnormal LMT (0.066 +/- 0.055) compared with 19 healthy volunteers (0.025 +/- 0.004) (p < 0.05, Mann Whitney test). Splanchnic ischemia is uncommon among patients with acute brain injury secondary to intracranial hemorrhage, provided they are adequately resuscitated with a protocol based mainly on fluids to achieve an adequate CPP. Gut hyperpermeability is commonly present, despite the absence of splanchnic ischemia.

Jugular Bulb Venous Oxygen Saturation During One-Lung Ventilation Under Sevoflurane- or Propofol-Based Anesthesia for Lung Surgery

During one-lung ventilation (OLV), systemic oxygenation can be compromised. In such a scenario, if anesthetic techniques were used that adversely affected cerebral oxygen balance, the risk for impaired cerebral oxygen balance may be increased. In this study, jugular bulb venous oxygen saturation (SjO(2)) during OLV under sevoflurane- or propofol-based anesthesia for lung surgery was investigated. Prospective clinical study. University hospital. Fifty-two adult patients scheduled for elective thoracic procedures in the lateral position. Patients were randomly allocated to either the sevoflurane or propofol group (n = 26). General anesthesia was maintained with sevoflurane or propofol combined with epidural anesthesia. Arterial and jugular bulb blood samples were measured before OLV, 15 minutes after OLV, 30 minutes after OLV, and 15 minutes after the termination of OLV. SjO(2) values in both sevoflurane and propofol groups significantly declined during OLV (p < 0.05). SjO(2) values in the sevoflurane group were higher than in the propofol group, although SaO(2) values were similar (p < 0.05). Regarding the incidence of SjO(2) <50% (cerebral oxygen desaturation), there were significant differences between the sevoflurane group and the propofol group during both normally ventilated conditions (0% v 7.7%, p < 0.05, relative risk [RR]: not applicable) and OLV (1.9% v 26.9%, p < 0.05, RR = 14; 95% confidence interval [CI] 1.91-103). Significant increase in the incidence of SjO(2) <50% during OLV was also observed only in the propofol group (from 7.7% to 26.9%, p < 0.05, RR = 3.5; 95% CI 1.29-12.4). Cerebral oxygen desaturation was more frequently detected during OLV under propofol- versus sevoflurane-based anesthesia. Cerebral oxygen balance during OLV for lung surgery was less impaired under sevoflurane-based anesthesia compared with propofol; however, the clinical outcome or implications for cognitive function need to be determined.

Jugular Bulb Oxygen-Desaturation Episodes During Functional Cerebral Hemispherotomies

To the Editor: Hemispherotomy, a modified functional hemispherectomy, is indicated in catastrophic unilateral epileptic syndromes where the substrate lies upon a diffuse hemispheric disease, with preservation of the contralateral hemisphere. Few published data describe anesthetic monitoring during this procedure (1–3). Monitoring jugular bulb venous oxygen saturation (Sjo2) in the healthy hemisphere gives useful information for maintaining adequate cerebral perfusion pressure and for setting the best ventilator characteristics to avoid hyperventilation and cerebral vasoconstriction (4,5). We report our experience with five patients with diffuse hemispheric disease, who underwent cerebral hemispherotomy. Because we continuously monitored Sjo2, we were able to detect and correct several episodes of severe desaturation. In each patient we inserted a fiberoptic oximetry catheter (Oximetrix, Abbott Critical Care Systems, North Chicago, IL) through the jugular vein ipsilateral to the healthy hemisphere, allowing us to continuously record Sjo2. In all patients, we detected several episodes of Sjo2 < 50% during neurosurgical procedures lasting from 7 h to 9 h 30 min. Representative episodes are shown in Table 1. These episodes were caused by modest hyperventilation, slight decreases in arterial blood pressure, or postural changes (e.g., reverse Trendelenburg position). Sjo2 normalized after we had several simultaneous adjustments: diminishing ventilation, increasing Fio2, and increasing arterial blood pressure. If we had not monitored Sjo2, we would have missed the impaired cerebral oxygenation, potentially resulting in intraoperative cerebral ischemia, increased postoperative morbidity, and impaired neurological outcome. All patients had good neurological outcomes.Table 1: Measured Hemodynamic and Respiratory VariablesNeus Fàbregas, MD, PhD Ivan Bel, MD Lydia Salvador, MD Ricard Valero, MD, PhD Enrique Carrero, MD Anesthesiology Department Hospital Clínic i Provincial de Barcelona University of Barcelona Barcelona, Spain [email protected] Jordi Rumià, MD Neurosurgical Department Hospital Clínic i Provincial de Barcelona University of Barcelona Barcelona, Spain

Effects of Increasing Concentrations of Propofol on Jugular Venous Bulb Oxygen Saturation in Neurosurgical Patients under Normothermic and Mildly Hypothermic Conditions

Recent evidence suggested that propofol can deteriorate the cerebral oxygen balance compared with inhalational anesthetics. However, dose-related influences of propofol on cerebral oxygen balances were not clearly investigated. In the current study, the authors investigated the effects of increasing concentrations of propofol on jugular venous bulb oxygen saturation (Sj(O2)) in neurosurgical patients under normothermic and mildly hypothermic conditions. After institutional approval and informed consent were obtained, 30 adult patients undergoing elective craniotomy were studied. Patients were randomly allocated to either normothermic or hypothermic group (n = 15 in each group). In the normothermic and hypothermic groups, tympanic membrane temperature was maintained at 36.5 degrees and 34.5 degrees C, respectively. Sj(O2) was measured at predicted propofol concentrations of 3, 5, and 7 microg/ml using a target-controlled infusion system in both groups. At a predicted propofol concentration of 3 microg/ml, there were no significant differences in Sj(O2) values between the normothermic and hypothermic groups, although the incidence of desaturation (Sj(O2) < 50%) was significantly higher in the normothermic group than in the hypothermic group (30% vs. 13%; P < 0.05). Sj(O2) values and the incidence of desaturation remained unchanged during the changes in predicted propofol concentration from 3 to 7 microg/ml both in the normothermic and hypothermic groups. The results indicated that the increasing concentrations of propofol did not affect Sj(O2) values in neurosurgical patients under normothermic and mildly hypothermic conditions.

Light-reflective cerebral oximetry and jugular bulb venous oxygen saturation during carotid endarterectomy.

A novel instrument using reflected near-infra-red light spectroscopy to measure cerebral oxygen saturation non-invasively was evaluated during carotid endarterectomy; cerebral perfusion was compared with jugular bulb venous oxygen saturation and transcranial Doppler ultrasonographic measurements. Initially, oximetry sensors with light source-detector separation distances of 10 and 27 mm were positioned over the frontal area, while a cannula positioned in the jugular bulb permitted sampling for jugular bulb venous oxygen saturation. To increase cerebral oxygen saturation sensitivity, modified sensors with light source-detector separation distances of 30 and 40 mm were relocated over the middle cerebral artery territory. The changes in cerebral and jugular bulb venous oxygen saturation, and in peak blood flow velocity before and 30 s after carotid clamping and declamping were recorded. The modified cerebral perfusion system achieved improved correlations between cerebral and jugular bulb venous oxygen saturation changes during carotid clamping and declamping (r = 0.92, P < 0.001). The correlation between change in cerebral oxygen saturation and the percentage change in peak flow velocity on both cross-clamping and declamping was equally strong (r = 0.90, P < 0.001). Near-infra-red cerebral spectroscopy reliably detects changes in cerebral oxygen saturation during carotid endarterectomy and may have wide applications in monitoring brain perfusion during neurosurgery and cardiopulmonary bypass surgery, and in closed head injury.

A Comparison of Tissue Oxygen Index With Jugular Venous Bulb Oxygen Saturation During Hypercapnic Challenge

s: 33rd Annual Meeting of the Society of Neurosurgical Anesthesia and Critical Care: MONITORING, GENERAL

Antecubital approach for monitoring jugular bulb venous oxygen saturation during carotid endarterectomy

Antecubital approach for monitoring jugular bulb venous oxygen saturation during carotid endarterectomy

Comparison of changes in jugular venous bulb oxygen saturation and cerebral oxygen saturation during variations of haemoglobin concentration under propofol and sevoflurane anaesthesia

A severe reduction in haemoglobin concentration can lead to a decrease in jugular venous bulb oxygen saturation (Sj(O(2))). However, recent evidences suggests that cerebral oxygen saturation (Sc(O(2))) measured by near infrared spectroscopy decreased during even mild haemodilution. We therefore tested the hypothesis that the changes in Sc(O(2)) may not be parallel to those in Sj(O(2)) during haemodilution. In addition, as cerebral oxygen balance during the operation can vary depending on the anaesthetics used, the changes in Sj(O(2)) and Sc(O(2)) during haemodilution were compared between patients under propofol and isoflurane/nitrous oxide anaesthesia. Forty-two patients with pre-donated autologous blood were randomly assigned to receive propofol (Group P) or sevoflurane/nitrous oxide (Group S) anaesthesia. A fibreoptic catheter was placed in the jugular bulb to measure Sj(O(2)). A cerebral oximeter, INVOS 4100S was used to monitor Sc(O(2)). Arterial and jugular bulb blood samples were drawn simultaneously at: (i) 10 min after the start of operation, (ii) after 400 ml of blood loss, (iii) after 800 ml of blood loss, (iv) just before the transfusion of pre-donated autologous blood, and (v) after 400 ml transfusion. Mean (sd) control values of Sj(O(2)) in Group P were significantly lower than those in Group S (55 (8)% vs 71 (10)%, respectively; P<0.05), whereas there was no significant difference in control values of Sc(O(2)) between the two groups. During the operation, haemoglobin (Hb) concentrations significantly deceased in the both groups compared with control values (from 9.8 to 7.6 g dl(-1) in Group P and from 9.9 to 8.0 g dl(-1) in Group S). During a reduction in Hb concentration, Sj(O(2)) values remained unchanged in both groups, whereas Sc(O(2)) values significantly decreased in both groups (from 57 to 51% in Group P and from 59 to 52% in Group S). The results indicated that, although the changes in Sj(O(2)) and Sc(O(2)) during a reduction in haemoglobin concentration were similar under propofol and sevoflurane/nitrous oxide anaesthesia, the changes in Sc(O(2)) were not parallel to those in Sj(O(2)). The discrepancy of the results in Sj(O(2)) and Sc(O(2)) may make the interpretation of their values difficult during haemodilution.

Hypothermia does not alter somatosensory evoked potential amplitude and global cerebral oxygen extraction during marked sodium nitroprusside-induced arterial hypotension.

To prevent neurologic damage, monitoring cerebral function by somatosensory evoked potentials is used in selected settings. Excision of intraocular melanoma provides a unique opportunity to assess independently during anesthesia the effects on median nerve somatosensory evoked potentials (MN-SSEPs) and cerebral oxygen extraction of sodium nitroprusside-evoked arterial hypotension with and without hypothermia. Median nerve somatosensory evoked potentials, arterial pressure, jugular venous bulb oxygen saturation (Sjo(2)) and lactate concentration, and arterial-jugular bulb oxygen content difference were assessed during propofol-remifentanil anesthesia under sodium nitroprusside-evoked arterial hypotension (mean arterial pressure, 40 mmHg) with and without surface hypothermia (32 degrees C) in 11 otherwise healthy patients undergoing resection of choroidal melanoma. Hypothermia alone did not affect peak-to-peak amplitude of N20/P25 but prolonged cortical latency of N20 (22.6 +/- 2.2 vs. 25.9 +/- 2.5 ms, P < 0.05), cervical latency of N13 (14.3 +/- 1.2 vs. 15.7 +/- 1.6 ms, P < 0.05), and central conduction time (8.3 +/- 1.4 vs. 10.2 +/- 1.6 ms, P < 0.05). Evoked arterial hypotension did not depress MN-SSEP N20/P25 amplitude either with or without hypothermia (-0.31 vs. -0.28 microV, P > 0.05) or alter latency (0.08 vs. 0.1 ms, P > 0.05). Furthermore, hypotension with or without hypothermia did not change Sjo(2), arterial-jugular bulb oxygen content difference, or lactate concentration. Thus, hypothermia to 32 degrees C does not alter MN-SSEP amplitude and global cerebral oxygen extraction during marked sodium nitroprusside-induced arterial hypotension with a mean arterial pressure of 40 mmHg but prolongs MN-SSEP latencies during propofol-remifentanil anesthesia in individuals without cerebrovascular disease.

The Association of High Jugular Bulb Venous Oxygen Saturation with Cognitive Decline After Hypothermic Cardiopulmonary Bypass

The Association of High Jugular Bulb Venous Oxygen Saturation with Cognitive Decline After Hypothermic Cardiopulmonary Bypass

パッチグラフトを用いたＣＥＡ 手術手技と中期成績

We examined the value of synthetic patch grafts in patients undergoing carotid endarterectomy (CEA). Patch grafting using a Hemashield was adopted in 22 CEA procedures. Mild hypothermia at 34°C was induced in the patients to reduce the risk of cerebral ischemia during carotid clamping. Monitoring by two kinds of cerebral oximetry was undertaken continuously to evaluate the cerebral blood flow. Cardiac output (CO) was calculated two times during normothermia and at 34°C. Systemic heparinization was induced intraoperatively, and was then continued 5 days postoperatively. The average clamping time of the carotid artery was 72 min.By inducing hypothermia, the jugular bulb venous oxygen saturation was raised by 2% on average (n=10). On the other hand, the CO did not change (n=7). The diameter of the internal carotid bulb was increased by 31% compared with that in primary closure. We did not encounter any cerebral ischemic events during the perioperative period. Postoperative follow-up has been continued for 20 months on average, and no restenosis of the internal carotid artery has been experienced in the patients. CEA with a patch graft under mild hypothermia was effective for reducing the occurrence of restenosis and the risk of cerebral ischemia.

Is there a correlation between neurone-specific enolase and jugular venous bulb oxygen saturation during CABG

s: European Association of Cardiothoracic Anaesthesiologists; 17th Annual Meeting; Dublin, Ireland; June 12-15, 2002: Cardiopulmonary Bypass and Surgery

Risk factors for disordered cerebral autoregulation during hypothermic cardiopulmonary bypass

Disordered cerebral autoregulation during cardiopulmonary bypass (CPB) is regarded as one of the causes of neurological dysfunction after cardiac surgery. However, little documentation of risk factors associated with cerebral autoregulation during CPB has been reported. Sixty consecutive patients undergoing coronary artery bypass were classified into subgroups according to whether they had preoperative cerebrovascular disease (CVD), hypertension (HT), or diabetes (DM). Cerebral oxygenation was monitored by jugular venous bulb oxygen saturation (SjvO2) and near-infrared spectroscopy parameter (%Oxy-Hb) during the operation, and the relationships between these values and intraoperative parameters were evaluated. The results showed that SjvO2 and %Oxy-Hb in the CVD+group were lower than in the CVD-group. Multiple stepwise regression analysis on SjvO2 and %Oxy-Hb in the CVD+ group revealed that only MAP was a predictive factor and that there was a positive correlation between MAP and both SjvO2 and %Oxy-Hb (r=.651,r=.693, respectively,P 0.0001), and the correlation was stronger in patients without any risk factors (r=.671,P=0.0001). The results suggested that patients with CVD, HT, and DM may experience failure of cerebral pressureflow autoregulation and cerebrovascular reactivity during CPB.

Jugular Bulb Venous Oxygen Saturation Monitoring in Brain Surgery

Jugular Bulb Venous Oxygen Saturation Monitoring in Brain Surgery

ＣＥＡ術中の脳酸素飽和度持続モニタリングによる脳循環動態の検出

We examined values of jugular bulb venous oxygen saturation (SjO2) and regional oxygen saturation (rSO2) in addition to electroencephalogram (EEG) monitoring to detect cerebral ischemia during carotid clamping in patients undergoing carotid endarterectomy (CEA). We summarize our finding based on a consecutive series of 10 patients. Six patients had unilateral lesion, and the remaining 4 patients had bilateral lesion or tandem lesion. We encountered cerebral ischemia, which was defined by EEG slowing, during carotid clamping in 2 patients. These patients demonstrated a concomitant decrease in rSO2 to 64% and 52%, respectively: a 10% decrease compared to the pre-clamping baseline in both patients. Contrarily, the SjO2 was maintained at almost the same level with that of pre-clamping. These results suggest that SjO2 is not sufficiently sensitive to detect cerebral ischemia during CEA. Continuous monitoring of rSO2 is adequately sensitive to detect cerebral ischemia, and 10% decrease in rSO2 may indicate cerebral ischemia.

Management of raised intracranial pressure in children.

Children suffer a significant number of head injuries as a result of their high activity levels, immature developmental skills and increased head-to-body mass ratio. Primary brain injury is irreversible, but secondary insults can be limited. Central to this is the management of raised intracranial pressure (ICP). The pathophysiology of head injury can explain some of the causes of raised ICP. Monitoring of ICP is important and this is closely linked to the maintenance of an adequate cerebral perfusion pressure and the importance of normovolaemia. Other interventions that have been shown to limit rises in ICP are appropriate use of positioning, mechanical ventilation and drug therapy. Less common therapies include jugular venous bulb oxygen saturation monitoring and the use of trometamol (THAM). Most nursing interventions do not actively reduce ICP, but they are central to its management. Reducing stimuli, avoiding cluster care, manual hyperinflation and limiting routine endotracheal suction may prevent an accumulative rise in ICP. Based on this literature review, it is possible to divide these interventions into first and second tier treatments, as shown in the protocol. Much of the suggested management will occur simultaneously, but it is important to assess the child's own response to each intervention and thus tailor treatment to minimize secondary brain injury.