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Biomedical subjects

B C Ong

Publications and source records attributed to B C Ong.

At least 19 recordsLinked to original sources
PubMed2006

A comparison of 5% dextrose in 0.9% normal saline versus non-dextrose-containing crystalloids as the initial intravenous replacement fluid in elective surgery.

Intravenous fluid replacement in adult elective surgery is often initiated with dextrose-containing fluids. We sought to determine if this practice resulted in significant hyperglycaemia and if there was a risk of hypoglycaemia if non-dextrose-containing crystalloids were used instead. We conducted a randomized controlled trial in 50 non-diabetic adult patients undergoing elective surgery which did not involve entry into major body cavities, large fluid shifts, or require administration of >500 ml of intravenous fluid in the first two hours of peri-operative care. Patients received 500 ml of either 5% dextrose in 0.9% normal saline, lactated Ringer's solution, or 0.9% normal saline over 45 to 60 minutes. Plasma glucose, electrolytes and osmolarity were measured prior to infusion, and at 15 minutes and one hour after completion of infusion. None of the patients had preoperative hypoglycaemia despite average fasting times of almost 13 hours. Patients receiving lactated Ringer's and normal saline remained normoglycaemic throughout the study period. Patients receiving dextrose saline had significantly elevated plasma glucose 15 minutes after completion of infusion (11.1 (9.9-12.2, 95% CI) mmol/l). Plasma glucose exceeded 10 mmol/l in 72% of patients receiving dextrose saline. There was no significant difference in plasma glucose between the groups at one hour after infusion, but 33% of patients receiving DS had plasma glucose > or = 8 mmol/l. We conclude that initiation of intravenous fluid replacement with dextrose-containing solutions is not required to prevent hypoglycaemia in elective surgery. On the contrary, a relatively small volume of 500 ml causes significant, albeit transient, hyperglycaemia, even in non-diabetic patients.

Adult↗
PubMed2003

Postoperative nausea and vomiting: a review of current literature.

INTRODUCTION: Postoperative nausea and vomiting (PONV) is one of the commonest complaints following anaesthesia, and can result in morbidity like wound dehiscence, bleeding, pulmonary aspiration of gastric contents, fluid and electrolyte disturbances, delayed hospital discharge, unexpected hospital admission, and decreased patient satisfaction. METHOD: A literature search was done on the Medline and relevant articles chosen. RESULTS: Despite the vast amount of research done in this field and the variety of antiemetic drugs available, PONV still has a high incidence. Many factors are associated with PONV. Quantifying the relative impact of risk factors on PONV has resulted in the development of risk models, which can stratify risk categories and hence allow the anaesthetist to identify those patients at higher risk for PONV. The management of PONV requires a multi-modal approach which can include the use of less emetogenic anaesthetic techniques, balanced analgesia, appropriate intravenous hydration, the use of pharmacotherapy and possibly non-pharmacologic methods. CONCLUSIONS: The use of risk models facilitates the judicious use of pharmacotherapy to ameliorate PONV especially in the high-risk patient and may lead to a more cost effective and efficient means of managing PONV.

Antiemetics↗
PubMed2001

Thermal capsular shrinkage: Basic science and clinical applications.

Recently, the use of thermal energy to shrink the redundant glenohumeral joint capsule in patients with instability has generated a great deal of interest. Proponents assert that the procedure avoids the need for an open stabilization and it may be used as an adjunct to an open or arthroscopic capsulolabral repair. The use of nonablative thermal energy to shrink soft-tissue collagen appears to induce ultra-structural and mechanical changes at or above 60 degrees C. The microscopic changes reflect the unwinding of the collagen triple helix and loss of the fiber orientation. The fibrils contract into a shortened state and reactive fibroblasts have been shown to grow into this treated area and synthesize the collagen matrix. The biomechanical properties of the tissue do not appear to be detrimentally altered if shrinkage is limited to less than 15% and if ablation or excess focal treatment is avoided. The endpoint of optimal shrinkage is not known and clinical estimations of tissue changes and volumetric reduction are used as guides to treatment. The first clinical follow-up study was only recently published in the peer-reviewed literature and prior preliminary reports were optimistic regarding the use of thermal energy for the treatment of glenohumeral instability. Thermal capsular shrinkage has been used as an adjunct to a capsulolabral repair, as well as an isolated treatment for the disorders of internal impingement and multidirectional instability. Additional evaluation is necessary to determine the optimal quantity of energy needed for tissue shrinkage without inadvertent tissue destruction. The long-term clinical effect, mechanical properties, and durability of the newly produced collagen need to be analyzed further. The basic science and clinical applications of this newly applied technology are reviewed in this article.

Animals↗
PubMed2001

Achilles tendon surgery: S-shaped surgical approach and postoperative positioning to minimize wound tension and external pressure.

For Achilles tendon surgery, an S-shaped incision may be made crossing the midline proximal to the transverse skin creases above the top of the heel counter. This incision provides wide exposure of the tendon and enables wound closure with minimal skin tension. After surgery, direct external pressure on the wound and dependent swelling of the Achilles tendon region, which may increase risks for wound dehiscence and infection, are minimized by laying the patient in the lateral decubitus or prone position to elevate the heel.

Achilles Tendon↗
PubMed2000

Acute patellar tendon rupture: A new surgical technique.

The most common method used in the treatment of acute patellar tendon ruptures is primary end-to-end repair. The use of the Acufex ACL guide (Acufex Microsurgical, Mansfield, MA) provides efficient and accurate placement of transosseous drill holes in the patella and minimizes the risk, tourniquet time, and surgical time of acute patellar tendon repairs.

Arthroplasty↗
PubMed2000

Fall incidence in a state psychiatric hospital in Singapore.

The results of a retrospective study of fall incidence during a 1-year period in a psychiatric hospital in Singapore are reported, involving 309 patients who fell one or more times during their stay. The profile of inpatients involved in falls was identified. Data were derived from standard incident forms completed whenever patients had a fall. A total of 348 falls were identified for the 1-year period. Results revealed higher fall rates in younger male epileptic patients; elderly female patients, age 70 and older with depression or dementia; individuals with concomitant medical conditions; and patients taking three types of medication. The majority of falls occurred when the activity level was high in the ward. Young epileptic patients and elderly depressed patients were prone to repeated falls. These results have the potential to assist in identifying patients at high risk and in designing and implementing strategies to prevent such incidents.

Accidental Falls↗
PubMed2000

Long-term follow-up of the one-bone forearm procedure.

The one-bone forearm procedure can be a successful salvage option for forearm stability in selected patients and is indicated if instability and bone loss are irreparable by other means. We report a case of a dysfunctional arm secondary to radical débridement of the ulna after osteomyelitis treated successfully with a one-bone forearm procedure and followed up for 8 years.

Adult↗
PubMed1999

Cesarean section in a mother with uncorrected congenital coronary to pulmonary artery fistula.

PURPOSE: We report a case of a 33 yr old woman with pulmonary hypertension secondary to uncorrected right coronary artery to pulmonary artery fistula who underwent two successful operative deliveries under general anesthesia. CLINICAL FEATURES: This woman underwent an emergency Caesarean section at 32 wk gestation because she presented in NYHA Class IV, heart failure and premature labour. She did not have antenatal follow-up. For her second pregnancy, she was managed from the first trimester of pregnancy by the cardiologist, obstetrician and anesthesiologist. She received oral furosemide and digoxin from eight weeks gestation. Pregnancy was managed to term before she progressed to NYHA Class IV and cardiac failure at 37 wk gestation. She had a Caesarean section under general anesthesia. She received rapid sequence induction of anesthesia and tracheal intubation with 0.1 mg x kg(-1) etomidate, 2 mg x kg(-1) succinylcholine and maintenance with nitrous oxide 50% in oxygen, isoflurane 1% and 0.1 mg x kg(-1) vecuronium. Fentanyl, 2 microg x kg(-1) helped to obtund the hypertensive response to intubation. Analgesia was provided with 1 mg x kg(-1) morphine. Glyceryl trinitrate infusion, 10-30 microg x min(-1) was used in addition to the anti-heart failure therapy. End-tidal capnography, electrocardiogram, pulse oximetry, continuous arterial blood pressure and pulmonary arterial catheter provided hemodynamic monitoring. The lungs were mechanically ventilated for 24 hr postoperatively. She received anti-heart failure therapy which she continued after discharge. She was NYHA class II upon discharge. She defaulted from further follow-up. CONCLUSION: Although the literature advocates, in this situation, controlled vaginal delivery utilising epidural analgesia, we describe the successful outcome for operative delivery under general anesthesia in a patient with secondary pulmonary hypertension and heart failure.

Adult↗
PubMed1999

Changing the institutional practice of prolonged mechanical ventilation after coronary artery bypass graft surgery to early extubation.

Since 1997 some of our cardiac anaesthetists have, whenever possible, extubated the patients early after cardiac surgery to improve their level of comfort, to allow an early return of the cardiopulmonary physiological function, and to help reduce health care costs. After a few months of implementing this practice, an audit was carried out to evaluate the success of early extubation after coronary artery bypass graft (CABG) surgery. Over a 6-month period starting from May 1997, the perioperative data of 110 consecutive patients with good or moderate left ventricular function scheduled for elective CABG were prospectively collected and analysed. The anaesthetic regime was according to the preference of the anaesthetists. Initially consent was obtained from the surgeons when the extubation criteria were fulfilled, but subsequently as the practice became more accepted by the surgeons, extubation was initiated by the anaesthetists. Within 4 hours of admission into the intensive care unit (ICU), 50 (45.5%) of the 110 patients satisfied the early extubation criteria and were extubated. The extubation criteria are described in the article. For the remaining patients, the median duration of mechanical ventilation was 14.3 hours. The profiles of the two groups of patients and the possible reasons for not extubating early are discussed. Forty-five per cent of the patients with moderate to good ventricular function were extubated safely within 4 hours of admission into the ICU after CABG surgery. With gradual acceptance of the practice and a change in mindset amongst all the care givers, more patients can benefit from this practice. This article highlights the challenges associated with changing institutional practices with respect to the postoperative care of cardiac patients.

Analysis of Variance↗
PubMed1998

Prevalence of factor V Leiden in a population of patients with congenital heart disease.

PURPOSE: The incidence of thrombotic events following cardiopulmonary bypass (CPB) in patients receiving surgical repair or palliation of congenital heart defects (CHD) is as high as 16%. Protein C, an intrinsic anticoagulation protease which, when activated, breaks down factor Va of the coagulation system, aids in maintaining a normal procoagulant/anticoagulant balance. Resistance of factor Va to degradation by activated protein C occurs and predisposes to thrombotic events. The resistance of factor Va to such degradation is, in the majority of cases, due to a genetic mutation referred to as factor V Leiden (FVLeiden). The presence of FVLeiden can be diagnosed using a DNA based assay. The prevalence of FVLeiden in the with CHD has not been determined. The objective of this study was to determine the prevalence of FVLeiden in patients with CHD. METHODS: Two hundred consecutive patients with CHD undergoing surgical repair or palliation requiring cardiopulmonary bypass were studied. Blood was taken before administration of homologous blood transfusion and assayed using a DNA based method with polymerase chain reaction amplification for the FVLeiden mutation. RESULTS: The prevalence of FVLeiden in our study population was 9/200 (4.5%). None of these patients demonstrated thrombotic complications. However, three patients (1.5%) without the FVLeiden mutation developed postoperative thrombotic complications. CONCLUSIONS: The prevalence of FVLeiden in patients is 4.5% that is not different from that of the population at large. There was no identifiable association with the occurrence of postoperative thrombotic events.

Anticoagulants↗
PubMed1998

Predicting the size of a double-lumen endobronchial tube based on tracheal diameter.

UNLABELLED: We assessed whether using the tracheal diameter to predict the correct size of the left double-lumen endobronchial tube (DLT) could be used for our generally smaller sized Asian patients. Sixty-six consecutive adult patients under anesthesia for elective surgery requiring the use of a DLT were studied. The size of the left-sided DLT used was based on the width of patients' trachea measured from the preoperative posterior-anterior chest radiograph. The placement of the DLT was standardized and confirmed with fiberoptic bronchoscopy. The correct size of the DLT was the largest size tube inserted into the left bronchus with a small air leak detectable when the endobronchial cuff was deflated but not exceeding the recommended resting volume when inflated for lung isolation. Using this method of choosing our DLT, we found that an oversized DLT was often chosen especially among our female Asian patients. The overall positive predictive values for the male and female patients were 77.3% and 45.5%, respectively. We postulate that this could be due to our criteria for correct DLT size or that our local Asian patients, especially the females, were smaller and shorter. IMPLICATIONS: This study assessed whether the correct double-lumen endobronchial tube size could be predicted from tracheal diameter measurements taken from the chest radiograph. We found that this method of choosing the double-lumen endobronchial tubes was not always reliable.

Adolescent↗
PubMed1998

A case report of heparin resistance due to acquired antithrombin III deficiency.

A case of heparin resistance and its management during cardiopulmonary bypass is reported. A patient with a history of post-infarct angina and arrhythmias was treated with intravenous heparin infusion for five days prior to myocardial revascularisation surgery. He required 13,500 IU/kg of heparin to increase his activated clotting time to a therapeutic level for safe institution of cardiopulmonary bypass. This phenomenon of heparin resistance was postulated to be due to consumption of circulating antithrombin III as a result of prior heparinisation. Treatment with fresh frozen plasma restored heparin effectiveness.

Aged↗