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T Gin

Publications and source records attributed to T Gin.

At least 19 recordsLinked to original sources
PubMed2005

Re-defining the ischemic threshold for jugular venous oxygen saturation--a microdialysis study in patients with severe head injury.

Neurological change is more likely to occur when jugular venous oxygen saturation (SjvO2) is less than 50%. However, the value indicating cellular damage has not been clearly defined. We determined the critical SjvO2 value below which intracerebral extracellular metabolic abnormalities occurred in 25 patients with severe head injury. All patients received standard treatment with normoventilation and maintenance of intracranial pressure < 20 mmHg. SjvO2 was measured from the dominant jugular bulb using a calibrated fibreoptic catheter. Intracerebral metabolic monitoring was performed by collecting perfusate from a microdialysis probe placed in the frontal lobe anterior to the intracranial catheter. Excitotoxin (glutamate) and other extracellular metabolites (lactate, glucose and glycerol) were measured frequently using enzymatic and colorimetric methods. We observed biphasic relationships between SjvO2 and all intracerebral metabolites. Analysis of variance showed that there were rapid increases in glutamate, glycerol and lactate when SjvO2 dropped below 40, 43 and 45% respectively. Extracellular glucose decreased when SjvO2 dropped below 42%. Our findings suggested that the ischemic threshold for SjvO2 in patients with severe head injury is 45%, below which secondary brain damage occurred.

Adolescent↗
PubMed2005

Effect of ischemic preconditioning on brain tissue gases and pH during temporary cerebral artery occlusion.

Previous studies have demonstrated that a brief period of ischemia protect against subsequent severe ischemic insults to the brain, i.e. preconditioning. We evaluated the effects of ischemic preconditioning, produced by 2 min proximal temporary artery occlusion, on brain tissue gases and acidity during clipping of cerebral aneurysm. Twelve patients with aneurysmal subarachnoid hemorrhage were recruited. All patients received standard anesthetics. After craniotomy, a calibrated multiparameter catheter was inserted to measure oxygen (PtO2) tension, carbon dioxide (PtCO2) tension and pH (pHt) in tissue at risk of ischemia during temporary artery occlusion. In patients assigned to the preconditioning group, proximal artery was occluded initially for 2 min and was allowed to reperfuse for 30 min. All patients underwent cerebral artery occlusion for clipping of aneurysm. The rate of change in PtO2, PtCO2 and pHt after artery occlusion were compared between groups using unpaired t test. Baseline brain tissue gases and pHt were similar between groups. Following artery occlusion, the decline in PtO2 and pHt were significantly slower in the preconditioning group compared with the routine care group. These results suggested that ischemic preconditioning attenuates tissue hypoxia during subsequent artery occlusion. Brief occlusion of the proximal artery may be a simple maneuver for brain protection during complex cerebrovascular surgery.

Adult↗
PubMed2005

Magnesium sulfate for brain protection during temporary cerebral artery occlusion.

We evaluated the effects of magnesium sulfate on brain tissue oxygen (PtO2) tension, carbon dioxide (PtCO2) tension and pH (pHt) in patients undergoing temporary artery occlusion for clipping of cerebral aneurysm. We studied 18 patients with aneurysmal subarachnoid hemorrhage. All patients received standard anesthetics using target controlled infusion of propofol (3 microg/ml) and remifentanil (10 ng/ml). After craniotomy, a calibrated multiparameter sensor (Neurotrend, Diametrics Medical, Minneapolis, MN) was inserted to measure PtO2, PtCO2 and pHt in tissue at risk of ischemia during temporary artery occlusion. Patients were then randomly allocated to receive either intravenous saline or magnesium 20 mmol over 10 min followed by an infusion 4 mmol/h. Plasma magnesium concentration, brain tissue gases and pHt were determined at baseline, 30 min after study drug infusion and 4 min after temporary clipping. Data were analyzed by factorial ANOVA with repeated measures. Intergroup difference was compared with unpaired t test. P value < 0.05 was considered significant. Patient characteristics, baseline brain tissue gases and pHt did not differ between groups. Magnesium infusion increased PtO2 by 34%. Following temporary artery occlusion, PtO2 and pHt decreased and PtCO2 increased in both groups. However, tissue hypoxia was less severe and the rate of PtO2 decline was slower in the magnesium group. Our data suggested that magnesium enhances tissue oxygenation and attenuates hypoxia during temporary artery occlusion.

Brain↗
PubMed2005

Monitoring of autoregulation using intracerebral microdialysis in patients with severe head injury.

We evaluated the performance of continuous intracerebral microdialysis to indicate the autoregulatory reserve in 36 severely head-injured patients. All patients received standard treatment with intracranial pressure (ICP) monitoring. A microdialysis probe was placed in the frontal cortex anterior to the ICP catheter. Perfusate was collected frequently and extracellular concentration of glutamate was measured online using enzymatic method. Autoregulatory index was calculated by comparing glutamate concentration with CPP using Pearson's correlation. A correlation coefficient (r) < 0.5 is considered as loss of autoregulation, whereas r values approach 0 indicate preserved autoregulation. The change of autoregulatory status over time was correlated with outcome at 6 months. Three patterns of autoregulatory profiles were identified. Patients with intact autoregulation had satisfactory outcome. Transient impairment of autoregulation may result in favorable outcome if patients responded to treatment. However, persistent loss of autoregulation was associated with poor outcome (P < 0.001). The correlation between extracellular glutamate concentration (by microdialysis) and CPP is a useful index of autoregulation in head-injured patients. It predicts clinical outcome and may be used to guide therapy.

Adolescent↗
PubMed2005

Intravenous magnesium sulfate to improve outcome after aneurysmal subarachnoid hemorrhage: interim report from a pilot study.

OBJECTIVES: Magnesium sulfate (MgSO4) may be useful in preventing neurological injury after subarachnoid haemorrhage (SAH). In this randomized, double-blind study we evaluated the safety and efficacy of MgSO4 infusion to improve clinical outcome after aneurysmal SAH. METHODS: With ethics committee approval and informed consents, 45 patients with SAH were randomly allocated to receive either MgSO4 80 mmol/day or saline infusion for 14 days. All patients also received intravenous nimodipine. Episodes of vasospasm were treated with hypertensive, hypervolemic therapy. Neurological status was assessed 3 months after haemorrhage using Barthel index and Glasgow outcome scale (GOS). Incidences of cardiac and pulmonary complications were also recorded. Data were compared between groups using Mann-Whitney or Fisher exact tests as appropriate. P < 0.05 was considered significant. RESULTS: Patient characteristics, severity of SAH and surgical treatment did not differ between groups. Although the number of episodes was not reduced, MgSO4 shortened the duration of vasospasm. Patients receiving MgSO4 tended to have fewer neurological deficits, better functional recovery and an improved score in GOS. However, none of these outcome variables reached statistical significance. The incidence of cardiac and pulmonary complications in the MgSO4 group (43%) was also similar to that in the saline group (59%), P = 0.14. CONCLUSIONS: MgSO4 infusion after aneurysmal SAH is well tolerated and may be useful in producing better outcome. A larger study is required to confirm the neuroprotective effect of MgSO4.

Comorbidity↗
PubMed2005

A prospective evaluation of health-related quality of life in Hong Kong Chinese patients with chronic non-cancer pain.

OBJECTIVE: To evaluate the health-related quality of life in Hong Kong Chinese patients with chronic non-cancer pain. DESIGN: Prospective cross-sectional survey. SETTING: Regional public hospitals, Hong Kong. PATIENTS: Patients attending out-patient pain management clinics between 1 July 2002 and 28 February 2003 were approached to complete a set of standardised questionnaires. MAIN OUTCOME MEASURES: Demographic profiles, treatment modality, litigation, compensation, social welfare status, Hospital Anxiety Depression Scale, and Medical Outcomes Survey short-form health survey (SF36). RESULTS: Data from 166 patients were analysed. The median numeric pain rating score was 6 (interquartile range, 2-10). Work-related injury occurred in 34.3% of patients, while another 34% were involved in pain-related litigation and 32% were receiving disability or unemployment benefit. Sixty-four percent of patients were managed by three or more disciplines, while 54.8% were also receiving complimentary alternative medical treatment, mainly traditional Chinese medicine (49.7%). The Hospital Anxiety Depression Score indicated clinical anxiety or depression in 71.1% of patients. All SF36 subscale scores were lower than the local population norm. Unemployed patients had higher depression scores (P = 0.005), while students or retirees had lower physical functioning scores (P = 0.004). Patients who were single had higher role emotion scores than those who were married or separated/widowed (P = 0.011). Logistic regression analysis showed that younger age (odds ratio = 0.95), being married (6.62), work-related injury (15.63) or higher general scores (1.03) were more likely to be associated with litigation. Social welfare benefit was associated with unemployment (3.39) and a lower level of physical functioning (0.98). CONCLUSION: There was a high prevalence of clinical anxiety, depression, and severe impairment in the health-related quality of life in Hong Kong Chinese patients with chronic non-cancer pain. Specific factors affected the health-related quality of life, likelihood of litigation, and social benefit.

Adult↗
PubMed2004

Out-patient chronic pain service in Hong Kong: prospective study.

OBJECTIVE: To examine the profile and referral pattern of patients attending an out-patient pain management service in Hong Kong. DESIGN: Prospective cross-sectional survey. SETTING: Regional public hospitals, Hong Kong. PATIENTS: All patients attending out-patient pain management clinics in the New Territories East public hospitals between 1 September and 31 December 2002. MAIN OUTCOME MEASURES: Demographic profiles, referring specialty, pain diagnosis, pain sites, duration and severity of pain, treatment modality, litigation, compensation, and social welfare status. Data were collected using a standardised questionnaire. RESULTS: Two hundred and forty-eight patients were interviewed. Most patients (70%) were middle-aged, with 21% over 60 years. Seventy-nine percent of patients were referred to the clinics either from orthopaedic surgeons (64.1%), general and other surgeons (14.9%), or general practitioners (3.6%). The median (range) duration of pain was 2.3 (0.08-26.7) years. The most common pain diagnoses were musculoskeletal back pain (46.4%) and neuropathic pain (27.8%). A total of 11.3% of the patients had two pain diagnoses, while 40.7% complained of pain in more than one location. Pain in the limbs was the most frequent complaint followed by the head, neck, and back. Approximately 38% of patients had tried four or more treatment modalities. Oral medication was the most common method (86.7%) of pain-relief treatment. More than half of the patients had also tried physiotherapy and traditional Chinese medicine. Approximately 37% of the patients were unemployed, while 31% were receiving social security subsidy. Eighty-six patients had pain associated with a work-related injury, and of these patients, 80% were involved in compensation claims. CONCLUSIONS: The profile of patients referred to the pain management clinics was complex. Patients were mainly referred from specialists. The economic implication in this group of patients is likely to be significant as many patients utilised multiple treatment modalities, were unemployed and on social welfare benefits, and were involved in compensation and litigation proceedings.

Chronic Disease↗
PubMed2003

Mainstream vs. sidestream capnometry for prediction of arterial carbon dioxide tension during supine craniotomy.

We compared the performance of mainstream capnometry as a measure of arterial carbon dioxide tension (Paco2) with sidestream recordings in adult neurosurgical patients undergoing supine craniotomy. Two hundred and forty patients were randomly assigned so that the end-tidal carbon dioxide tension (PEco2) was measured using either a mainstream or sidestream infrared capnometer. All patients received propofol anaesthesia and ventilation was adjusted according to clinical requirement. Arterial blood gas analyses were performed after induction, prior to dural incision, during surgery and before wound closure. Simultaneous haemodynamic and ventilatory parameters were also recorded. For 1007 paired measurements of PEco2 and Paco2 (mainstream, n = 503; sidestream, n = 504), the mean (SD) mainstream arterial to end-tidal carbon dioxide tension difference, 0.64 (0.16) kPa, was smaller than the corresponding sidestream values, 0.99 (0.40) kPa (p < 0.001). The limits of agreement for the mainstream analyser, 0.32-0.96 kPa, were also narrower than the sidestream recordings, 0.19-1.79 kPa (p < 0.001). In both capnometers, the arterial to end-tidal difference in carbon dioxide tension did not change with time. However, there was greater within-patient variation in the sidestream group. Our study showed that mainstream PEco2 provided a more accurate estimation of Paco2 than sidestream measurement.

Adolescent↗
PubMed2002

Patient-controlled epidural analgesia in a parturient with hypertrophic obstructive cardiomyopathy.

We describe the use of patient-controlled epidural analgesia (PCEA) using fentanyl in the management of a labouring parturient with hypertrophic obstructive cardiomyopathy (HOCM). With non-invasive monitoring, PCEA was started in the early first stage of labour with a bolus dose of fentanyl 20 microg, lockout 5 min and 4-h maximum dose of 500 microg. Analgesia was satisfactory during the early first stage but was poor subsequently, despite a total fentanyl consumption of 760 microg during the 6-h labour. The maternal cardiovascular condition was stable throughout labour and delivery and the baby was born in good condition without subsequent respiratory depression. Opioid-based PCEA is an alternative to systemic analgesia in labouring parturients with HOCM. However, although its use avoids the potential adverse effects of sympathetic block associated with conventional epidural analgesia, our regimen had limited analgesic efficacy in the latter stage of labour.

Journal Article↗
PubMed2001

Patient-controlled pethidine after major upper abdominal surgery: comparison of the epidural and intravenous routes.

We compared epidural (n = 17) and intravenous (n = 20) patient-controlled analgesia (PCA) using pethidine (bolus 10 mg, lockout interval 10 min, 4-h maximum dose 3 mg.kg(-1)) after total gastrectomy. We found that mean (SD) pethidine consumption in the first 24 h was 33% less in the epidural group [255 (85) mg] than in the intravenous group [379 (129) mg, p = 0.002], although most of this difference occurred in the first 8 h. Plasma concentrations of pethidine were lower at 8 h (p < 0.01) in the epidural group, but were similar at 24 h. Pain scores, side-effects, patient satisfaction and patient outcome were similar between groups. Epidural and intravenous pethidine PCA provided similar efficacy after major abdominal surgery, although the epidural route can reduce the amount of pethidine used initially.

Adolescent↗
PubMed2001

Ipsilateral thoraco-lumbar anaesthesia and paravertebral spread after low thoracic paravertebral injection.

We report ipsilateral thoraco-lumbar anaesthesia and paravertebral spread of contrast after injection through a thoracic paravertebral catheter that was placed at the right T8-9 spinal level for pain management in a patient with multiple fractured ribs. We review the literature and describe the subendothoracic fascial communication between the thoracic paravertebral space and the retroperitoneal lumbar paravertebral region, which we propose, is the anatomical basis for ipsilateral thoraco-lumbar anaesthesia and paravertebral spread of contrast in our patient.

Extravasation of Diagnostic and Therapeutic Materi↗
PubMed2001

The pharmacokinetics of once-daily dosing of ceftriaxone in critically ill patients.

The aim of this study was to determine the pharmacokinetic profile of the normal recommended dose of ceftriaxone in critically ill patients and to establish whether the current daily dosing recommendation maintains plasma concentrations adequate for antibacterial efficacy. Ceftriaxone at a recommended dose of 2 g iv was administered od to 12 critically ill patients with severe sepsis and normal serum creatinine concentrations. Blood samples were taken at pre-determined intervals over the first 24 h and on day 3 for measurement of ceftriaxone concentrations. There was wide variability in drug disposition, explained by the presence of variable renal function and identified by the measurement of creatinine clearance. In nine patients with normal renal function, there was a high level of creatinine clearance (mean +/- S.D., 41 +/- 12 mL/min) and volume of distribution (20 +/- 3.3 L), which resulted in an elimination half-life of 6.4 +/- 1.1 h. In comparison with normal subjects, ceftriaxone clearance was increased 100%, volume of distribution increased 90% and the elimination half-life was similar. Three patients had substantially suboptimal plasma ceftriaxone concentrations. We confirm previous findings that ceftriaxone clearance in critically ill patients correlates with renal clearance by glomerular filtration. The elimination half-life is prolonged (21.4 +/- 9.8 h) in critically ill patients with renal failure when compared with previously published data in non-critically ill patients with renal failure. We conclude that in critically ill patients with normal renal function, inadequate plasma concentrations may result following od bolus dosing of ceftriaxone. Drug accumulation may occur in critically ill patients with renal failure.

Adolescent↗
PubMed2001

A prospective survey of patients after cessation of patient-controlled analgesia.

UNLABELLED: Cessation of IV patient-controlled analgesia (PCA) in the postoperative period is often an arbitrary clinical decision. We conducted a prospective survey of patients 24 h after cessation of IV PCA morphine to determine whether they wished to be restarted on PCA, and to evaluate factors affecting this decision. One hundred and fifteen patients were surveyed over a 3-mo period. Thirty-eight patients (33%) wished to restart PCA. The most common reason was the expectation that IV PCA would be more effective. Age, sex, type of surgery, duration of PCA use, side effects, pain scores, and reasons for cessation of PCA did not affect the decision. The reasons given by those who did not wish to restart PCA were minimal pain (51.9%), inconvenient PCA machine (15.6%), ineffective analgesia by IV PCA (11.7%), side effects during PCA (11.7%), and wishing to tolerate pain (7.8%). PCA morphine consumption in the 24-h period before cessation of PCA (mean [SD]) was larger in patients wishing to restart PCA than in those who did not (21.1 [14.8] mg vs 15.1 [15.1] mg; P < 0.05). In conclusion, the clinical decisions to cease IV PCA do not predict patient acceptance of and satisfaction with the decision and with subsequent pain treatment. Morphine consumption may predict a patient's acceptance of ceasing PCA. IMPLICATIONS: We surveyed patients 24 h after cessation of IV patient-controlled analgesia (PCA). This survey revealed that the usual clinical reasons to stop IV PCA might not be the most appropriate. Patients have different reasons why they wish to restart or not restart IV PCA. The cessation of PCA should be individualized.

Adult↗
PubMed2001

Plasma homocysteine, methylene tetrahydrofolate reductase C677T and factor II G20210A polymorphisms, factor VIII, and VWF in central retinal vein occlusion.

AIMS: To determine whether plasma homocysteine, methylene tetrahydrofolate reductase (MTHFR) C677T and factor II G20210A polymorphisms, factor VIII, and vWF are risk factors for central retinal vein occlusion (CRVO). METHOD: Prospective comparison of 63 consecutive patients with central retinal vein occlusion and 63 age matched controls. Plasma homocysteine and vWF were estimated by ELISA, the MTFHR and factor II G20210A polymorphisms determined by polymerase chain reaction with restriction enzyme product digestion and factor VIII by one stage automated clotting assay. RESULTS: Plasma homocysteine (patients: median 12.4 micromol/l, controls: median 11.6 micromol OR = 1.05, p=0.20), factor VIII (patients: median = 115 U/dl, controls: median = 113 U/dl), and vWF (patients: median = 115 U/dl, controls: median = 108 U/dl) were not statistically higher in patients than in controls. Five CRVO patients and seven controls were homozygous for the MTHFR C677T mutation. One control was heterozygous for the factor II G20210A mutation. CONCLUSION: This study has not identified new risk factors for CRVO.

Blood Coagulation↗
PubMed2000

Alfentanil given immediately before the induction of anesthesia for elective cesarean delivery.

Opioids are routinely omitted at the induction of general anesthesia for cesarean delivery because of concerns about neonatal respiratory depression. The subsequent unmodified maternal stress response to tracheal intubation reduces placental perfusion. The short-acting opioid alfentanil may afford advantages at the induction, without subsequent neonatal depression. In this double-blinded study of elective cesarean deliveries, 40 patients were allocated randomly to receive either alfentanil 10 microg/kg (n = 18) or placebo (n = 22), 1 min before the induction of anesthesia with thiopental 4 mg/kg and succinylcholine 1.5 mg/kg. Anesthesia was maintained with 50% nitrous oxide, 0.5% isoflurane in oxygen, and atracurium. Neonates were assessed by using Apgar scores, Neurologic and Adaptive Capacity Scores, and umbilical cord blood gas and catecholamine analysis. After intubation, mothers receiving alfentanil had a smaller increase in mean arterial blood pressure, (11 +/- 15 vs 31 +/- 13 mm Hg, P < 0.001) and lower plasma norepinephrine concentrations, (336 +/- 152 vs 486 +/- 241 pg/mL, P < 0.05). Neonates in the alfentanil group had greater umbilical arterial oxygen tensions (27.8 +/- 7.0 vs 22.6 +/- 7.4 mm Hg), slightly reduced Apgar scores (both P < 0.05), but similar Neurologic and Adaptive Capacity Scores. One neonate in the alfentanil group required naloxone. The maternal stress response was attenuated in the alfentanil group but at the cost of early neonatal depression. However, all neonates should be monitored for possible immediate, but transient, respiratory depression.

Adult↗
PubMed2000

A dose-response study of prophylactic intravenous ephedrine for the prevention of hypotension during spinal anesthesia for cesarean delivery.

UNLABELLED: We performed a randomized, double-blinded dose-finding study of IV ephedrine for prophylaxis for hypotension in 80 women who received an IV crystalloid preload and spinal anesthesia for elective cesarean delivery. One minute after the intrathecal injection, patients were given saline control or ephedrine 10, 20, or 30 mg IV for 30 s. Systolic arterial pressure (SAP) in the first 12 min after the spinal injection was greater in the 30-mg group compared with other groups (P < 0.05). Hypotension occurred in 7 patients (35%) in the 30-mg group compared with 19 (95%), 17 (85%), and 16 (80%) patients in the control and 10- and 20-mg groups, respectively (P < 0.0001). Maximum decrease in SAP was smaller in the 30-mg group (mean lowest SAP 87% of baseline, range 58%-105%) compared with other groups (P < 0.01). Reactive hypertension occurred in 9 patients (45%) in the 30-mg group (mean highest SAP 120% of baseline, range 104%-143%) compared with 2 (10%), 1 (5%), and 5 (25%) patients in the other groups (P = 0.009). Heart rate changes, total ephedrine requirement, incidence of nausea and vomiting, and neonatal outcome were similar among groups. The proportion of patients with umbilical arterial pH < 7.2 was 10.5%, 25%, 42%, and 22% in the control, 10-, 20-, and 30-mg groups, respectively (P = 0. 12). We conclude that the smallest effective dose of ephedrine to reduce the incidence of hypotension was 30 mg. However, this dose did not completely eliminate hypotension, nausea and vomiting, and fetal acidosis, and it caused reactive hypertension in some patients. IMPLICATIONS: We investigated different doses of IV ephedrine as prophylaxis for hypotension during spinal anesthesia for cesarean delivery and found that the smallest effective dose was 30 mg. However, this dose did not completely eliminate hypotension, caused reactive hypertension in some patients, and did not improve neonatal outcome.

Acidosis↗
PubMed2000

TIMP-3, collagen, and elastin immunohistochemistry and histopathology of Sorsby's fundus dystrophy.

PURPOSE: Mutations in the tissue inhibitor of metalloproteinases-3 (TIMP-3) gene have previously been identified in patients with Sorsby's fundus dystrophy (SFD). We evaluated the ocular distribution of TIMP-3 and other extracellular constituents in SFD. METHODS: The eyes of an SFD donor with a confirmed TIMP-3 mutation were examined using histologic techniques demonstrating connective tissue, calcium, and lipid. Immunohistochemical analyses were performed using antibodies against TIMP-3, collagen type IV, V, and VI, laminin, fibronectin, elastin, and fibrillin. Electron microscopy also was used. RESULTS: A subretinal pigment epithelium (sub-RPE) deposit similar to that previously described was seen. A morphologically similar but different deposit was present internal to the nonpigmented ciliary epithelium (NPCE). Both deposits contained collagens, elastin, glycosaminoglycans, lipids, and calcium. Immunolabeling of TIMP-3 was found in the basement membrane of the NPCE, Bruch's membrane, and choroidal vessels in normal control subjects. In SFD, immunolabeling of TIMP-3 also was present in the sub-RPE deposit and in the inner portion of the ciliary body deposit. TIMP-3 immunoreactivity was more extensive in the SFD eye. The pattern of elastin immunoreactivity was remarkably similar to that of TIMP-3. Electron microscopy revealed a morphologically altered elastic layer of the Bruch's membrane. CONCLUSIONS: Sub-RPE TIMP-3 immunoreactivity appears more extensive in SFD than in control subjects. There is also a correspondence between TIMP-3 and elastin immunoreactivies, which invites speculation as to a link between the SFD TIMP-3 mutation and altered elastin processing. The accumulation of abnormal material in SFD is more widespread than previously reported. In view of this, SFD might be better termed Sorsby's ocular epitheliopathy.

Aged↗