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Jae Hong Lee

Publications and source records attributed to Jae Hong Lee.

5 recordsLinked to original sources
PubMed2005

Posttraumatic vasospasm: the epidemiology, severity, and time course of an underestimated phenomenon: a prospective study performed in 299 patients.

OBJECT: The purpose of this prospective study was to evaluate the cumulative incidence, duration, and time course of cerebral vasospasm after traumatic brain injury (TBI) in a cohort of 299 patients. METHODS: Transcranial Doppler (TCD) ultrasonography studies of blood flow velocity in the middle cerebral and basilar arteries (VMCA and VBA, respectively) were performed at regular intervals during the first 2 weeks posttrauma in association with 133Xe cerebral blood flow (CBF) measurements. According to current definitions of vasospasm, five different criteria were used to classify the patients: A (VMCA > 120 cm/second); B (VMCA > 120 cm/second and a Lindegaard ratio [LR] > 3); C (spasm index [SI] in the anterior circulation > 3.4); D (VBA > 90 cm/second); and E (SI in the posterior circulation > 2.5). Criteria C and E were considered to represent hemodynamically significant vasospasm. Mixed-effects spline models were used to analyze the data of multiple measurements with an inconsistent sampling rate. Overall 45.2% of the patients demonstrated at least one criterion for vasospasm. The patients in whom vasospasm developed were significantly younger and had lower Glasgow Coma Scale scores on admission. The normalized cumulative incidences were 36.9 and 36.2% for patients with Criteria A and B, respectively. Hemodynamically significant vasospasm in the anterior circulation (Criterion C) was found in 44.6% of the patients, whereas vasospasm in the BA-Criterion D or E-was found in only 19 and 22.5% of the patients, respectively. The most common day of onset for Criteria A, B, D, and E was postinjury Day 2. The highest risk of developing hemodynamically significant vasospasm in the anterior circulation was found on Day 3. The daily prevalence of vasospasm in patients in the intensive care unit was 30% from postinjury Day 2 to Day 13. Vasospasm resolved after a duration of 5 days in 50% of the patients with Criterion A or B and after a period of 3.5 days in 50% of those patients with Criterion D or E. Hemodynamically significant vasospasm in the anterior circulation resolved after 2.5 days in 50% of the patients. The time course of that vasospasm was primarily determined by a decrease in CBF. CONCLUSIONS: The incidence of vasospasm after TBI is similar to that following aneurysmal subarachnoid hemorrhage. Because vasospasm is a significant event in a high proportion of patients after severe head injury, close TCD and CBF monitoring is recommended for the treatment of such patients.

Adult↗
PubMed2002

Multimodal quantitation of the effects of endovascular therapy for vasospasm on cerebral blood flow, transcranial doppler ultrasonographic velocities, and cerebral artery diameters.

OBJECTIVE: The goal of this study was to quantify the effects of endovascular therapy on vasospastic cerebral vessels. METHODS: We reviewed the medical records for 387 patients with ruptured intracranial aneurysms who were treated at a single institution (University of California, Los Angeles) between May 1, 1993, and March 31, 2001. Patients who developed cerebral vasospasm and underwent cerebral arteriographic, transcranial Doppler ultrasonographic, and cerebral blood flow (CBF) studies before and after endovascular therapy for cerebral arterial spasm (vasospasm) were included in this study. RESULTS: Forty-five patients fulfilled the aforementioned criteria and were treated with either papaverine infusion, papaverine infusion with angioplasty, or angioplasty alone. After balloon angioplasty (12 patients), CBF increased from 27.8 +/- 2.8 ml/100 g/min to 28.4 +/- 3.0 ml/100 g/min (P = 0.87); the middle cerebral artery blood flow velocity was 1 57.6 +/- 9.4 cm/s and decreased to 76.3 +/- 9.3 cm/s (P < 0.05), with a mean increase in cerebral artery diameters of 24.4%. Papaverine infusion (20 patients) transiently increased the CBF from 27.5 +/- 2.1 ml/100 g/min to 38.7 +/- 2.8 ml/100 g/min (P < 0.05) and decreased the middle cerebral artery blood flow velocity from 109.9 +/- 9.1 cm/s to 82.8 +/- 8.6 cm/s (P < 0.05). There was a mean increase in vessel diameters of 30.1% after papaverine infusion. Combined treatment (13 patients) significantly increased the CBF from 33.3 +/- 3.2 ml/100 g/min to 41.7 +/- 2.8 ml/100 g/min (P< 0.05) and decreased the transcranial Doppler velocities from 148.9 +/- 12.7 cm/s to 111.4 +/- 10.6 cm/s (P < 0.05), with a mean increase in vessel diameters of 42.2%. CONCLUSION: Balloon angioplasty increased proximal vessel diameters, whereas papaverine treatment effectively dilated distal cerebral vessels. In our small series, we observed no correlation between early clinical improvement or clinical outcomes and any of our quantitative or physiological data (CBF, transcranial Doppler velocities, or vessel diameters).

Adult↗
PubMed2002

Progressive hemorrhage after head trauma: predictors and consequences of the evolving injury.

OBJECT: Progressive intracranial hemorrhage after head injury is often observed on serial computerized tomography (CT) scans but its significance is uncertain. In this study, patients in whom two CT scans were obtained within 24 hours of injury were analyzed to determine the incidence, risk factors, and clinical significance of progressive hemorrhagic injury (PHI). METHODS: The diagnosis of PHI was determined by comparing the first and second CT scans and was categorized as epidural hematoma (EDH), subdural hematoma (SDH), intraparenchymal contusion or hematoma (IPCH), or subarachnoid hemorrhage (SAH). Potential risk factors, the daily mean intracranial pressure (ICP), and cerebral perfusion pressure were analyzed. In a cohort of 142 patients (mean age 34 +/- 14 years; median Glasgow Coma Scale score of 8, range 3-15; male/female ratio 4.3: 1), the mean time from injury to first CT scan was 2 +/- 1.6 hours and between first and second CT scans was 6.9 +/- 3.6 hours. A PHI was found in 42.3% of patients overall and in 48.6% of patients who underwent scanning within 2 hours of injury. Of the 60 patients with PHI, 87% underwent their first CT scan within 2 hours of injury and in only one with PHI was the first CT scan obtained more than 6 hours postinjury. The likelihood of PHI for a given lesion was 51% for IPCH, 22% for EDH, 17% for SAH, and 11% for SDH. Of the 46 patients who underwent craniotomy for hematoma evacuation, 24% did so after the second CT scan because of findings of PHI. Logistic regression was used to identify male sex (p = 0.01), older age (p = 0.01), time from injury to first CT scan (p = 0.02), and initial partial thromboplastin time (PTT) (p = 0.02) as the best predictors of PHI. The percentage of patients with mean daily ICP greater than 20 mm Hg was higher in those with PHI compared with those without PHI. The 6-month postinjury outcome was similar in the two patient groups. CONCLUSIONS: Early progressive hemorrhage occurs in almost 50% of head-injured patients who undergo CT scanning within 2 hours of injury, it occurs most frequently in cerebral contusions, and it is associated with ICP elevations. Male sex, older age, time from injury to first CT scan, and PTT appear to be key determinants of PHI. Early repeated CT scanning is indicated in patients with nonsurgically treated hemorrhage revealed on the first CT scan.

Adolescent↗
PubMed2002

Efficacy of hyperventilation, blood pressure elevation, and metabolic suppression therapy in controlling intracranial pressure after head injury.

OBJECT: Hyperventilation therapy, blood pressure augmentation, and metabolic suppression therapy are often used to reduce intracranial pressure (ICP) and improve cerebral perfusion pressure (CPP) in intubated head-injured patients. In this study, as part of routine vasoreactivity testing, these three therapies were assessed in their effectiveness in reducing ICP. METHODS: Thirty-three patients with a mean age of 33 +/- 13 years and a median Glasgow Coma Scale (GCS) score of 7 underwent a total of 70 vasoreactivity testing sessions from postinjury Days 0 to 13. After an initial 133Xe cerebral blood flow (CBF) assessment, transcranial Doppler ultrasonography recordings of the middle cerebral arteries were obtained to assess blood flow velocity changes resulting from transient hyperventilation (57 studies in 27 patients), phenylephrine-induced hypertension (55 studies in 26 patients), and propofol-induced metabolic suppression (43 studies in 21 patients). Changes in ICP, mean arterial blood pressure (MABP), CPP, PaCO2, and jugular venous oxygen saturation (SjvO2) were recorded. With hyperventilation therapy, patients experienced a mean decrease in PaCO2 from 35 +/- 5 to 27 +/- 5 mm Hg and in ICP from 20 +/- 11 to 13 +/- 8 mm Hg (p < 0.001). In no patient who underwent hyperventilation therapy did SjvO2 fall below 55%. With induced hypertension, MABP in patients increased by 14 +/- 5 mm Hg and ICP increased from 16 +/- 9 to 19 +/- 9 mm Hg (p = 0.001). With the aid of metabolic suppression, MABP remained stable and ICP decreased from 20 +/- 10 to 16 +/- 11 mm Hg (p < 0.001). A decrease in ICP of more than 20% below the baseline value was observed in 77.2, 5.5, and 48.8% of hyperventilation, induced-hypertension, and metabolic suppression tests, respectively (p < 0.001 for all comparisons). Predictors of an effective reduction in ICP included a high PaCO2 for hyperventilation, a high study GCS score for induced hypertension, and a high PaCO2 and a high CBF for metabolic suppression. CONCLUSIONS: Of the three modalities tested to reduce ICP, hyperventilation therapy was the most consistently effective, metabolic suppression therapy was variably effective, and induced hypertension was generally ineffective and in some instances significantly raised ICP. The results of this study suggest that hyperventilation may be used more aggressively to control ICP in head-injured patients, provided it is performed in conjunction with monitoring of SjvO2.

Adult↗