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Biomedical subjects

D H Tay

Publications and source records attributed to D H Tay.

9 recordsLinked to original sources
PubMed1998

Intrathecal sufentanil as the sole agent in combined spinal-epidural analgesia for the ambulatory parturient.

PURPOSE: To compare the effect of a combination of intrathecal (i.t.) sufentanil plus bupivacaine with i.t. sufentanil alone, on the incidence of hypotension and the success of ambulation in parturients. METHODS: This was a controlled, double-blind prospective trial involving 50 parturients in early labour who had received combined spinal-epidural analgesia (CSE). They were divided equally into two groups; group A received 10 micrograms i.t. sufentanil while group B received i.t. 10 micrograms sufentanil plus 2.5 mg plain bupivacaine. The blood pressure, pain scores, the highest sensory block and the degree of motor blockade were documented over the first 30 min by an unbiased anaesthetist. The ability and the desire to ambulate was studied 30 min after CSE. The side effects were documented throughout labour. RESULTS: Group B had a higher incidence of hypotension; (12 vs 3: P < 0.01). Fewer parturients in group B could ambulate (19 vs 25: P < 0.05). Group B also had a higher sensory blockade than group A (median T4 VS T7-8: P < 0.01). Of all the 44 parturients who could ambulate, 13 desired not to do so, usually due to sedation. CONCLUSION: The quality of analgesia in all subjects in the study was excellent. Side effects were more common in the i.t. sufentanil-bupivacaine combination group.

Analgesia, Epidural↗
PubMed1995

The effects of gynaecological surgery on coagulation activation, fibrinolysis and fibrinolytic inhibitor in patients with and without ketorolac infusion.

The effects of gynaecological surgery on the fibrinolytic and inhibitor mechanisms were followed up for 24 h post-operatively in patients receiving a single dose of ketorolac infusion (n = 18) as compared with those not receiving ketorolac infusion (n = 11). A pre-operative state of lower mean t-PA activity and higher PAI-1 levels with increased platelet activation than that reported in normal subjects were observed in both groups of patients. Increased t-PA activity upon anaesthetic induction together with a decreased level at 24 h post-operation was seen in both groups. However, fibrinolytic 'shut-down' was not evident as significant increase in D-dimer levels was observed post-operatively, suggesting an enhanced lytic state concurrent with an enhanced activation of coagulation and diminished platelet activation although beta-TG remained above the normal level; plasmin from this enhanced lytic state affects platelet adhesion and cleaves platelet glycoprotein Ib thus inhibit release reaction. Ketorolac infusion elicited a significant response in PAI-1 activity within 24 h post-operation and this was not seen in the non-ketorolac group in spite of the rising trend by 24 h post-operation which did not achieve statistical significance. There were no statistical significant differences in blood loss and duration of surgery between the two groups of patients. Overall, both groups of patients showed similar haemostatic changes post-operatively for 24 h, a longer duration of post-operative study would have revealed any subtle changes in the molecular markers of thrombosis which was not the objective of this study.

Adult↗
PubMed1994

A comparison of three types of tracheal tube for use in laryngeal mask assisted blind orotracheal intubation.

Laryngeal mask assisted blind orotracheal intubation is a technique that is best mastered under controlled circumstances. The influence of the type of tracheal tube, and positioning of the head, on the success rate of this procedure was evaluated in 90 gynaecological patients presenting for elective procedures under general anaesthesia. After induction, a laryngeal mask was introduced and its position was confirmed. Up to three attempts at blind orotracheal intubation using one of three tracheal tubes (Argyle, Portex or Kendall Curity) passed through the laryngeal mask were permitted in each patient. The success rates after a single attempt at blind oral intubation were 3.3%, 70.0% and 30.0% respectively (p < 0.001 and p < 0.05 when Portex was compared to Argyle and Kendall Curity types). After a maximum of three attempts, success rates were 30.0% (Argyle), 93.3% (Portex) and 76.7% (Kendall Curity). The first attempt at tracheal intubation was performed in the 'sniffing the morning air position' and this was successful in 52% of successful intubations; the second attempt using extension at the atlanto-occipital joint was successful in a further 35% of successful intubations; the third attempt used varying degrees of neck flexion and extension at the atlanto-occipital joint and this permitted successful placement of the tracheal tube in the remaining 13% of patients in whom tracheal intubation was possible.

Female↗
PubMed1994

Lignocaine 0.5% for spinal anaesthesia in gynaecological day surgery.

Spinal anaesthesia with 5 ml of lignocaine 0.5% was administered to 30 women presenting for day case minor gynaecological surgery. They were allocated at random to receive the anaesthetic via either a 26-gauge Atraucan (pencil point) or a 29-gauge Spinocan (cutting bevel) spinal needle. Onset, duration, spread and regression of sensory and motor blockade, haemodynamic parameters and postoperative complications were studied. An upper sensory level of T10 (93.3%) was obtained in all except two patients. No patient complained of discomfort during surgery. The mean onset time was less than 8 min and the mean duration of sensory block was 32.5 min. All patients had complete return of motor power within 1 h and were discharged the same day. Only one patient had a transient episode of hypotension which was easily treated with intravenous fluids. There were no serious side effects seen postoperatively. We conclude that spinal anaesthesia with 5 ml of lignocaine 0.5% provides a useful alternative to general anaesthesia for day case minor gynaecological surgery.

Adult↗
PubMed1994

Continuous spinal analgesia--initial experiences with differential sensory block and labour pain relief.

This report describes the use of microcatheters to provide continuous spinal analgesia for the relief of labour pain. Bupivacaine 0.025% was administered through a 28G spinal microcatheter resulting in a differential block which provided effective labour pain relief. Conduction by the smaller pain fibres from the uterus were blocked, while relatively sparing the larger A fibres. Motor power, sense of touch, and discrimination between blunt and sharp objects were therefore left relatively intact. Patients were thus spared the discomfort of motor paralysis and an intense sensory block. No patient had hypotension (blood pressure fall greater than 20%). However one patient suffered a severe post-dural puncture headache which required an epidural blood patch. Continuous intra-thecal spinal analgesia is a potential alternative to continuous epidural analgesia in the relief of labour pain.

Adult↗
PubMed1993

Venous air embolism during cesarean section: more common than previously thought.

To confirm the incidence of venous air embolism (VAE), we simultaneously monitored expired nitrogen concentration (FEN2) and precordial Doppler in 30 patients undergoing cesarean delivery during general anesthesia. Patients were randomized into two groups and the effect of a 10 degrees reverse Trendelenburg tilt versus the horizontal position was evaluated. Forty-two episodes of VAE, defined by an increase in FEN2 of 0.1%, were detected in 97% (29/30) of patients. Doppler ultrasound failed to detect 9 of the episodes and 23 (41%) changes in Doppler tones were not associated with an increase in FEN2. These spurious Doppler signals were synchronous with compression of retroperitoneal structures, suggesting turbulent venous return to be the cause. The reverse Trendelenburg position did not reduce the incidence of VAE. Compared with the preinduction baseline, mean arterial blood pressure decreased by 31.5 +/- 10.1 mm Hg in this position and 22.6 +/- 13.4 mm Hg in the supine position after hysterotomy. We conclude that VAE in cesarean delivery during general anesthesia occurs very frequently, and that changes in Doppler tones may not be reliable indicators of this complication. Measures to reduce the size and effect of air emboli therefore should be applied routinely in all patients.

Adult↗
PubMed1992

High-volume spinal anaesthesia. A dose-response study of bupivacaine 0.125%.

The clinical effects of high-volume spinal anaesthesia with bupivacaine 0.125% were studied in 30 patients presenting for postpartum sterilisation. Group A, B and C patients received 6, 8 and 10 ml of bupivacaine 0.125% respectively. Onset, duration and regression of sensory block and motor blockade, haemodynamic parameters and postoperative complications were studied. A sensory level of T10 was reliably obtained in Group B and C but not in Group A. Similarly motor blockade was unreliable in Group A compared with Group B (P < 0.05) and Group C (P < 0.05). Two segment regression times were similar in all three groups. L1 regression times were 47.9, 94.3 and 99.0 minutes in Groups A, B and C respectively. The corresponding times for complete recovery of motor power were 120, 212.3 and 182.7 minutes respectively (P < 0.01 when Group A compared to B and C). A significant incidence of high spinal anaesthesia occurred when 10 ml bupivacaine 0.125% was administered (P < 0.05 when compared with Group A). No patient experienced respiratory discomfort in spite of sensory levels of up to T1. Hypotension responded readily to intravenous fluids and small doses of ephedrine (three patients). Only one patient (Group A) developed a postdural puncture headache. In this study, high-volume spinal anaesthesia with bupivacaine 0.125% was found to be satisfactory for postpartum tubal ligation. The optimal volume of bupivacaine 0.125% was 8 ml.

Adult↗
PubMed1991

Is sedation without desaturation possible?

The correlation between the depth of sedation and the degree of oxygen desaturation was studied in 52 patients presenting for surgery under regional anaesthesia. After establishing successful regional anaesthesia, patients were sedated with incremental doses of intravenous midazolam. The various levels of sedation were scored from 0 to IV. Continuous pulse oximetry allowed for correlation of sedation and saturation. Each patient's presedation oxygen saturation served as the control value. This was compared with the saturation at sedation levels II, III and IV and was found to be significantly higher (p less than 0.001). There was also a significant drop in saturation as patients progressed from sedation level II to III (p less than 0.02) and from level III to IV (p less than 0.001). The incidence of saturation falling to less than 90% was 4.35%, 14.71% and 40% at sedation scores of II, III and IV respectively.

Adult↗