Biomedical subjects

C S Robertson

Publications and source records attributed to C S Robertson.

At least 73 records · Page 4Linked to original sources

PubMed1996

Evaluation of a carbohydrate-free diet for patients with severe head injury.

Hyperglycemia, which may be caused or exacerbated by conventional diets, may worsen the neurological outcome from severe head injury, especially if secondary ischemic insults occur. The purpose of this study was to evaluate an experimental diet intended to replace systemic caloric and protein requirements without producing hyperglycemia. In initial studies in the laboratory, 5 experimental diets were employed in a middle cerebral artery temporary occlusion model. The effects of the diets on blood biochemistry and on infarction volume were compared in fasted animals and in animals fed a control diet. Animals fed the experimental diets had a significantly lower preischemia blood glucose concentration, a higher blood concentration of ketone bodies, and a smaller infarct volume than the animals fed a control diet. One diet chosen from the laboratory study was then evaluated in a clinical study as a randomized, open-label trial. Twenty severely head-injured patients were randomly assigned to be fed the experimental diet, EN-9305, or the control diet, Osmolyte HN, for the first 2 weeks after injury. Both treatment groups had similar blood glucose concentrations, averaging 6.33 +/- 0.21 mumol/mL (114 +/- 4 mg/dL), on day 1 prior to starting the assigned diet. Blood glucose concentration increased in the control diet group to a peak of 8.37 +/- 0.94 mumol/mL (151 +/- 17 mg/dL) on day 7 as the infusion rate of the diet was increased to the final rate. In the experimental diet group, the blood glucose concentration remained unchanged from fasting levels as the diet was advanced. Blood lactate concentration was lower, and blood ketone body concentrations were higher in the patients fed the experimental diet. Urinary nitrogen balance was better in the experimental diet group, but measures of visceral protein sparing, including serum albumin, plasma retinol binding protein, and total lymphocyte count, were not significantly different in the 2 treatment groups. Measures of cerebral anaerobic metabolism, including CSF lactate concentration and cerebral lactate production, were not significantly different in the 2 treatment groups. These studies suggest that a carbohydrate-free diet such as EN-9305 might have advantages for patients with severe head injury by replacing systemic caloric and protein requirements without producing hyperglycemia.

Adult↗

PubMed1996

Activation of ornithine decarboxylase and accumulation of putrescine after traumatic brain injury.

Activation of ornithine decarboxylase (ODC), the initial enzyme in polyamine synthesis, and accumulation of putrescine are thought to mediate pathological processes in the ischemic and traumatized brain. Past studies have separately investigated either ODC or polyamines after head injury. The purpose of the present study was to quantify both ODC activity and polyamines in the rat parietal cortex before and after controlled cortical impact injury. Adult, male rats underwent a right craniectomy and were subjected to a 5 m/sec, 2-mm deformation impact injury. Rats were sacrificed 1, 4, 8, and 24 h postimpact and tissues from the injured (right) and contralateral (left) hemisphere were analyzed for ODC and polyamines. ODC activity was determined by measuring the decarboxylation of [14C]ornithine to putrescine. Putrescine, spermidine, and spermine were determined by high performance liquid chromatography. Cortical impact induced a 10- to 20-fold increase in ODC activity and a 4- to 5-fold increase in putrescine in the ipsilateral cortex. Spermidine and spermine did not significantly increase in the ipsilateral (right) cortex compared to controls (right cortex). In contrast, there was a slight increase in spermidine content in the contralateral (left) cortex after injury. The delayed increase in ODC activity and accumulation of putrescine may mediate pathophysiological changes observed after head injury.

Animals↗

PubMed1996

Lactate and excitatory amino acids measured by microdialysis are decreased by pentobarbital coma in head-injured patients.

Primary traumatic brain injury and secondary ischemic/hypoxic injury are being increasingly characterized at the neurochemical level. Neurochemical monitoring using microdialysis has shown that these forms of tissue damage share many common features. In particular, anaerobic glycolysis with increased lactate production and release of excitatory amino acids into the extracellular space are seen in both conditions. Clinical microdialysis studies have heretofore focused on methodological issues, establishment of basal analyte values, and clinico-neurochemical correlation. Here we report the neurochemical consequences of therapeutic intervention in head injury. Specifically, induction of thiopental coma to manage severe increased intracranial pressure in seven patients was associated with a 37% reduction of lactate, 59% reduction of glutamate, and 66% reduction in aspartate in the extracellular space of the brain.

Adolescent↗

PubMed1996

Intraoperative jugular desaturation during surgery for traumatic intracranial hematomas.

Traumatic intracranial hematomas which are present on hospital admission or which develop during the hospital course are associated with a worse neurological outcome than diffuse injuries. The purpose of this study was to monitor jugular venous oxygen saturation (Sjvo2) during surgery for evacuation of traumatic intracranial mass lesions, to determine the incidence and the causes of jugular venous desaturation, and to assess the usefulness of Sjvo2 monitoring in this setting. Twenty-five severely head injured patients were monitored during 27 surgical procedures. At the start of the surgical procedure, the median Sjvo2 was 47% (range 25%-89%). Seventeen (63%) of the patients had a Sjvo2 less than 50%. Five patients had extremely low Sjvo2 values (< or = 30%). Upon evacuation of the intracranial hematoma, there was a significant (P < 0.001) increase in the median Sjvo2 to 65% (range 50%-88%). Intracranial hypertension was the primary cause of the low Sjvo2, as confirmed by the response to surgical evacuation. Hypotension (mean arterial pressure < 80 mm Hg) was a contributing factor in seven of the cases of jugular desaturation. The definitive treatment of a traumatic intracranial hematoma is surgical evacuation. However, during the period prior to evacuation of the hematoma, jugular venous desaturation was common, suggesting that monitoring Sjvo2 might provide useful information about the adequacy of cerebral perfusion.

Adult↗

PubMed1995

Effect of carbon dioxide pneumoperitoneum on bacteraemia and endotoxaemia in an animal model of peritonitis.

Laparoscopy is increasingly used in conditions complicated by peritonitis. A theoretical concern is that carbon dioxide pneumoperitoneum may increase bacteraemia. This study examines the effect of carbon dioxide pneumoperitoneum on bacteraemia, endotoxaemia and physiological correlates of sepsis in an animal model of peritonitis. New Zealand white rabbits were assigned to three groups of six animals. Group 1 received an intraperitoneal inoculation of 10(9) colony-forming units of Escherichia coli followed by a 10-cm midline laparotomy. Group 2 received an identical bacterial inoculum followed by a 12-mmHg carbon dioxide pneumoperitoneum for 1 h. Group 3 received no bacteria but had a 12-mmHg carbon dioxide pneumoperitoneum for 1 h. Groups 1 and 2 had significantly higher levels of bacteraemia (P < 0.01) and endotoxaemia (P < 0.01) accompanied by significantly lower mean arterial pressures (P < 0.05) and higher heart rates (P < 0.05) compared with group 3. After 6 h groups 1 and 2 were significantly hypocarbic (P < 0.01), leucopenic (P < 0.01) and thrombocytopenic (P < 0.01). There was no difference between group 1 and group 2. A carbon dioxide pneumoperitoneum of 12 mmHg does not increase bacteraemia or endotoxaemia, nor does it adversely affect physiological or laboratory correlates of sepsis compared with laparotomy in this animal model of peritonitis.

Animals↗

PubMed1995

The influence of glycine and related compounds on spinal cord injury-induced spasticity.

Spasticity is a frequent and complex sequel to spinal cord injury. The neurochemical basis for the origin of spasticity is largely unknown. Glycine is among the most abundant neurotransmitters in the spinal cord. However, the role of glycine and related compounds in spasticity have received little attention. An ischemic spinal cord injury was created in rabbits, by an intraaortic balloon occlusion technique, which produced lower limb spasticity. A catheter was inserted into the cisterna magna and the spinal cord was bathed with 100 microM solutions of glycine, strychnine, D-serine, beta-alanine, MK-801, or artificial CSF for 4 hours at a rate of 10 microliters/min. H-reflexes were monitored before and during infusion by stimulating the posterior tibial nerve and recording from the plantar surface of the foot. Glycine, D-serine, and MK-801 depressed the H wave, strychnine produced a heightened H wave, and beta-alanine caused no significant changes. These results indicate that glycine and related compounds may influence spasticity.

Animals↗

PubMed1995

Intracranial pressure waveform indices in transient and refractory intracranial hypertension.

Analysis of data obtained by continuous computerized monitoring of intracranial pressure (ICP) in 109 adult patients with severe head trauma was performed to examine the pattern of change in indices of the ICP waveform. Indices derived from direct measurement of the ICP wave and obtained from a Fast Fourier Transform (FFT) were examined. Concurrent physiologic measurements were made. Two types of intracranial hypertension (ICH) were defined for comparison. 'Transient intracranial hypertension' occurred when an abrupt rise in ICP was followed by a return to below 25 mm Hg (n = 63). Increases in ICP that were progressive and led to neurologic deterioration and death were termed 'refractory intracranial hypertension' (n = 18). During transient ICH heart rate, arterial pressure, end-tidal carbon dioxide and jugular venous oxygen saturation all increased, while these measures either were unchanged or decreased during refractory ICH. The pulse amplitude of the ICP wave increased in both types of ICHtn. Other changes in the waveform indices were consistent with this change in pulse amplitude. HFC responded differently to the two types of changes, with an increase during the transient changes and a decrease during the refractory changes. The differences in changes in physiologic measurements as ICH occurred in the 2 groups suggest that in refractory ICH cerebral blood flow is maintained against the mounting ICP, while in transient ICH the hypertension is caused by an increase in cerebral blood flow. The waveform indices do not discriminate between the two types of changes.

Adult↗

PubMed1995

A new application for near-infrared spectroscopy: detection of delayed intracranial hematomas after head injury.

Clinical studies have documented the importance of secondary brain insults in determining neurologic outcome after head injury. Delayed intracranial hematomas are one of the most easily remediable causes of secondary injury if identified early, but can cause significant disability or death if not promptly recognized and treated. Early identification and treatment of these lesions that appear or enlarge after the initial CT scan may improve neurological outcome. Serial examinations using near-infrared spectroscopy (NIRS) to detect the development of delayed hematomas were obtained in 167 patients. The difference in absorbance of light (deltaOD) at 760 nm between the normal and the hematoma side was measured serially during the first 3 days after injury. Twenty-seven (16%) of the patients developed some type of late hematoma: an intracerebral hematoma in 8 patients, an extracerebral hematoma in 6 patients, and a postoperative hematoma in 13 patients. Eighteen of the delayed hematomas caused significant mass effect and required surgical evacuation. The hematomas appeared between 2 and 72 h after admission. In 24 of the 27 patients, a significant increase (>0.3) in the deltaOD occurred prior to an increase in intracranial pressure or a change in the neurological examination, or a change on CT scan. Early diagnosis using MRS may allow early treatment and reduce secondary injury caused by delayed hematomas.

Cerebral Hemorrhage↗

PubMed1995

SjvO2 monitoring in head-injured patients.

Jugular venous oxygen saturation (SjvO2) measures the balance between cerebral oxygen delivery and cerebral oxygen consumption. Abnormalities that increase oxygen consumption (e.g., fever or seizures) or that decrease oxygen delivery (e.g., increased ICP, hypotension, hypoxia, hypocapnia, or anemia) can decrease SjvO2. Measuring SjvO2 continuously in the ICU in 177 patients with severe head injury, jugular venous desaturation (SjvO2 < 50%) was identified at least once in 39% of the patients. Approximately half of the episodes of desaturation were due to intracranial hypertension and half were due to systemic causes. The occurrence of one or more episodes of desaturation was strongly associated with a poor outcome, suggesting that the reduction in oxygen delivery identified with the SjvO2 monitoring contributed to the neurological injury. In the operating room, jugular venous desaturation was identified in 6 of 8 patients who were monitored during emergency evacuation of a traumatic intracranial hematoma. The lowest SjvO2 observed was 28%. In all 8 cases, the SjvO2 increased, from 47 +/- 10% to 63 +/- 5% after evacuation of the hematoma. Additional data supporting the hypothesis that these secondary insults identified with the SjvO2 monitoring contribute to the patient's neurological injury come from measurement of the extracellular concentrations of lactate and excitatory amino acids in the brain using microdialysis. Lactate concentration increased from 0.9 +/- 0.3 to 2.4 +/- 0.5 mumol/L and glutamate increased from 11.5 +/- 8.5 to 55.0 +/- 10.4 mumol/L during 8 episodes of jugular venous desaturation in 7 of 22 patients monitored with microdialysis. SjvO2 identifies global reductions in cerebral oxygenation due to a variety of causes, and is useful as a monitor for secondary insults in patients with severe head injury.

Adult↗

PubMed1995

Laparoscopic left adrenalectomy: a new approach.

Left adrenalectomy has been performed previously via anterior, posterior, loin or thoracoabdominal approaches. In the classical transabdominal approach the left adrenal gland is resected following either mobilization of the spleen with the tail of the pancreas or after entering the lesser sac, mobilizing the inferior border of the pancreas off the adrenal gland. This report describes laparoscopic left adrenalectomy, in a patient with Conn's syndrome, performed by a new approach via the root of the left transverse mesocolon.

Adrenalectomy↗

PubMed1995

Clinical evaluation of a miniature strain-gauge transducer for monitoring intracranial pressure.

In 25 patients, we evaluated the accuracy of a new miniature strain-gauge transducer developed for the measurement of intracranial pressure (ICP). The ICP in each patient was measured with the intraventricular, miniature strain-gauge transducer, and that value was compared with the ICP measured with a ventriculostomy catheter coupled to an external strain-gauge transducer. From the two monitors, 2218 simultaneous measurements of ICP were obtained. The average ICP measured with the miniature strain-gauge transducer was 15.9 +/- 10.0 mm Hg (range, -3 to 104 mm Hg). The ICP measured with the ventriculostomy-catheter transducer averaged 15.4 +/- 10.1 mm Hg (range, -9 to 104 mm Hg). A highly significant correlation was found over the wide range of pressures observed (n = 2218, r = 0.97, P < 0.001). The average difference between the two measurements of the ICP was 0.5 +/- 2.6 mm Hg, and the differences were equally positive and negative, demonstrating no consistent bias. The two values for the ICP were within 2 mm Hg of each other on 63% of the measurements and within 4 mm Hg of each other on 89% of the measurements. The average zero drift of the miniature strain-gauge transducer, measured at ambient pressure after removal of the catheter, was 0.2 +/- 0.5 mm Hg. The results indicate that this miniature strain-gauge transducer is highly accurate and stable and that it is a reliable alternative to a ventriculostomy for monitoring the ICP.

Adult↗

PubMed1995

Early detection of delayed traumatic intracranial hematomas using near-infrared spectroscopy.

Delayed intracranial hematomas are an important treatable cause of secondary brain injury in patients with head trauma. Early identification and treatment of these lesions, which appear or enlarge after the initial computerized tomography (CT) scan, may improve neurological outcome. Serial examinations using near-infrared spectroscopy (NIRS) to detect the development of delayed hematomas were performed in 167 patients. The difference in absorbance of light (delta OD) at 760 nm between the normal and the hematoma side was measured serially during the first 3 days after injury. Twenty-seven (16%) of the patients developed a type of late hematoma: intracerebral hematoma in eight, extracerebral hematoma in six, and postoperative hematoma in 13 patients. Eighteen of the delayed hematomas caused significant mass effect and required surgical evacuation. The hematomas appeared between 2 and 72 hours after admission. In 24 of the 27 patients, a significant increase (> 0.3) in the delta OD occurred prior to an increase in intracranial pressure, a change in the neurological examination, or a change on CT scan. A favorable outcome occurred in 67% of the patients with delayed hematomas, which suggests that early diagnosis using NIRS may allow early treatment and reduce secondary injury caused by delayed hematomas.

Adolescent↗

PubMed1995

Cerebral metabolic management.

Knowledge of cerebral metabolic variables increases the information available for managing the head-injured patient. This article reviews normal cerebral metabolism and describes the derangement of metabolism observed in patients with head trauma. Cerebral metabolism is globally decreased by one third to one half in the severely head-injured patient, usually because of the lower metabolic expenditure associated with coma, but sometimes because of superimposed hypoxia/ischemia, primarily due to secondary insults. Measurement of jugular venous oxygen saturation has become the most useful method for monitoring cerebral metabolism in the ICU. Although jugular venous oxygen saturation does not provide quantitative information about either cerebral blood flow or cerebral metabolism, it reflects the ratio between these two variables. To maintain a sufficient level of available oxygen and energy production at the cellular level, there are two therapeutic strategies: a) hemodynamic and b) metabolic. Treatments can be directed at both increasing oxygen delivery and integrating hemodynamic handling, and at various pharmacologic or physical methods intended to reduce the cerebral metabolic demand. The latter strategy is designed to depress either the basal or activation components of cerebral metabolism. This strategy includes manipulations of brain temperature and the use of central nervous system-depressant, barbiturate, and similar drugs.

Blood Gas Analysis↗

PubMed1994

Two-team synchronous oesophagectomy.

Between 1984 and 1992, 131 patients underwent two-team synchronous oesophagectomy for carcinoma. Some 95 per cent of tumours were successfully resected by this technique. In 5 per cent of patients the tumour was found to be irresectable at operation and gastric bypass was performed. The overall operative mortality rate was 8 per cent and the pulmonary complication rate 10 per cent. The actuarial survival rate was 55 per cent at 1 year, 22 per cent at 3 years and 16 per cent at 5 years. When compared with the traditional two-stage Lewis approach, two-team synchronous oesophagectomy was significantly faster (mean 222 versus 282 min), but was not significantly different with respect to blood loss, transfusion requirement, pulmonary complications or operative mortality rate. Patients undergoing two-team oesophagectomy had a significantly shorter hospital stay than those receiving the two-stage procedure (mean 16 versus 24 days).

Actuarial Analysis↗

PubMed1994

Lateral cortical impact injury in rats: cerebrovascular effects of varying depth of cortical deformation and impact velocity.

Intracranial pressure (ICP), blood pressure (BP), cerebral perfusion pressure (CPP), and cortical perfusion (LDF) of the contralateral parietal cortex were measured after cortical impact injury in 36 rats. Changes in these physiologic parameters were compared using analysis of variance to a group of 11 rats who received a sham impact. In one series of experiments, the velocity and duration of the impact injury were kept constant, and the severity of the injury was determined by varying the depth of cortical deformation from 2 to 3 mm. The peak pressure inside the skull was directly related to the depth of cortical deformation, and was 93 +/- 16, 182 +/- 18, and 268 +/- 57 mm Hg with the 2, 2.5, and 3 mm deformation, respectively, when the impact velocity was 5 m/sec. With the 2 mm depth injury, there was a transient decrease in BP (p < 0.05) and a 12% decrease in LDF after the impact. With the 2.5 mm depth injury, a small transient increase in ICP and decrease in BP and a 30% decrease in LDF occurred (p < 0.05). ICP then gradually increased throughout the 8 h experiment, becoming significantly greater than the sham-injured animals by 5 h after the impact. LDF gradually returned toward normal throughout the experiment. With the 3 mm depth injury, a marked transient increase in ICP (p < 0.05) and BP (p < 0.05) occurred immediately after the impact. The increase in BP lasted < 5 min, and subsequently the BP decreased to approximately 50 mm Hg for the rest of the experiment. The initial marked increase in ICP lasted 15 min and then remained 5-10 mm Hg higher (p < 0.05) than in the sham-injured animals for the rest of the experiment. LDF decreased by an average of 50% (p < 0.05) immediately after the impact and remained lower than that of the sham-injured animals for the rest of the experiment. In another series of experiments, the depth of cortical deformation was kept constant at 2.5 mm, and the severity of the injury was determined by varying the velocity from 1 to 5 m/sec. The peak ICP was significantly related to the impact velocity, averaging 45 +/- 12, 66 +/- 9, and 182 +/- 18 mm Hg with the 1, 3, and 5 m/sec impact injuries, respectively. The 1 m/sec impact had no effect on ICP and only a transient decrease in BP.(ABSTRACT TRUNCATED AT 400 WORDS)

Analysis of Variance↗

PubMed1994

Lateral cortical impact injury in rats: pathologic effects of varying cortical compression and impact velocity.

Direct lateral cortical impact through the intact leptomeninges using a pneumatically driven piston produces increasingly severe pathophysiologic derangements with increasing cortical deformation. We studied the histopathologic correlates of cortical impact injury produced by 2 mm, 2.5 mm, and 3 mm deformation in the rat at 5 m/sec. Additionally, the effect of impact velocity at a 2.5 mm deformation was assessed at 1 m/sec, 3 m/sec, and 5 m/sec. The brains were examined 14 days after injury. Cortical contusion maximum cross-sectional area, volume, and the percentage CA1 and CA3 hippocampal neuronal loss correlate with cortical deformation and impactor velocity. Contusion volume increased with increasing cortical deformation. Deformations of 2, 2.5, and 3 mm at 5 m/sec produced contusion volumes of 4.59, 8.9, and 21.68 mm3, respectively. At a fixed cortical deformation of 2.5 mm, contusion volume increased with increasing impact velocity. Impact velocities of 1, 3, and 5 m/sec produced contusion volumes of 5.79, 7.42, and 8.9 mm3, respectively. Hippocampal CA3 neuronal loss increased with increasing cortical deformation. Deformations of 2, 2.5, and 3 mm at 5 m/sec produced neuronal loss of 29%, 48.3%, and 79.5%, respectively. At a fixed cortical deformation of 2.5 mm, hippocampal CA3 neuronal loss increased with increasing impact velocity. Impact velocities of 1, 3, and 5 m/sec produced neuronal loss of 18.25%, 33.75%, and 48.3%, respectively. Hippocampal CA1 neuronal loss was also seen and paralleled cortical deformation and impact velocity. Cortical deformation and impact velocity are critical parameters in producing cortical contusion and must be considered when comparing results using this model.

Animals↗

PubMed1994

A prospective randomized trial comparing R1 subtotal gastrectomy with R3 total gastrectomy for antral cancer.

OBJECTIVE: The authors determined if more radical surgery with extended lymphadenectomy improves the results of gastrectomy in patients with adenocarcinoma of the gastric antrum. SUMMARY BACKGROUND DATA: The overall survival in patients with gastric cancer is disappointing. Improved survival has been reported by Japanese authors. Whether this is because of a higher number of early gastric cancers in the Japanese series, different biologic behavior in Asians, or the adoption of radical surgery with lymphadenectomy remains unclear. METHODS: R1 subtotal gastrectomy with omentectomy and R3 total gastrectomy (omentectomy, splenectomy, distal pancreatectomy, lymphatic clearance of the celiac axis, and skeletonization of vessels in the porta hepatis) were evaluated in a prospective, randomized comparison. RESULTS: Fifty-five patients were randomized--25 to the R1 group and 30 to the R3 group. The two groups were comparable for age, sex, tumor size, TNM stage, and length of follow-up. The R3 group had a longer operating time (140 vs. 260 min; p < 0.05), a greater transfusion requirement (0 vs. 2 units, p < 0.05) and a longer hospital stay (8 vs. 16 days; p < 0.05) (medians; Mann-Whitney U test). The only postoperative death was in the R3 group and was caused by intra-abdominal sepsis. Fourteen patients in the R3 group developed left subphrenic abscesses. There were no major complications in the R1 group. Overall survival was significantly better in the R1 group (median survival estimated by Kaplan-Meier method, 1511 vs. 922 days, p < 0.05, log-rank test). CONCLUSIONS: R3 total gastrectomy can be performed with a low mortality, but it has a high morbidity because of intra-abdominal sepsis. The data do not support the routine use of R3 total gastrectomy for treatment of patients with antral cancer.

Adenocarcinoma↗

PubMed1994

Jugular venous desaturation and outcome after head injury.

Early experience with continuous monitoring of jugular venous oxygen saturation (SjvO2) suggested that this technology might allow early identification of global cerebral ischaemia in patients with severe head injury. The purpose of the present study was to examine the relationship between episodes of jugular venous desaturation and neurological outcome. One hundred and sixteen severely head-injured patients had continuous monitoring of SjvO2 during days 1-5 after injury. Episodes of jugular venous desaturation (SjvO2 < 50% for more than 10 minutes) were prospectively identified, and the incidence of desaturation was correlated with neurological outcome: 77 episodes of desaturation occurred in 46 of the 116 patients; 27 had one episode and 19 had multiple episodes of desaturation. The causes of these episodes were systemic (n = 36), cerebral (n = 35), or both (n = 6). Most of the episodes were less than 1 hour in duration, and it is probable that many of them would not have been detected without continuous measurement of SjvO2. Episodes of desaturation were most common on day 1 after injury, and were twice as common in patients with a reduced cerebral blood flow as in patients with a normal or elevated cerebral blood flow. The occurrence of jugular venous desaturation was strongly associated with a poor neurological outcome. The percentage of patients with a poor neurological outcome was 90% with multiple episodes of desaturation and 74% in patients with one desaturation, compared to 55% in patients with no episodes of desaturation. When adjusted for all co-variates that were found to be significant, including age, Glasgow coma score, papillary reactivity, type of injury, lowest recorded cerebral perfusion pressure, and highest recorded temperature, the incidence of desaturation remained significantly associated with a poor outcome. Although a cause and effect relationship with outcome cannot be established in this study, the data suggest that monitoring SvO2 might allow early identification and therefore treatment of many types of secondary injury to the brain.

Adolescent↗