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Biomedical subjects

M Wattwil

Publications and source records attributed to M Wattwil.

At least 37 records · Page 2Linked to original sources
PubMed1994

Effects of epidural morphine and epidural bupivacaine on gastroduodenal motility during the fasted state and after food intake.

The effects of a thoracic epidural analgesia with morphine or bupivacaine on gastroduodenal motility during the fasted state and after food intake were evaluated in healthy volunteers. Nine volunteers were studied on two occasions, separated by at least 2 weeks, and were randomly allocated to receive either epidural morphine or epidural bupivacaine at the T6-T7 level on each occasion. Gastroduodenal motility was measured by manometry. Acetaminophen absorption was used as an indirect measure of the rate of gastric emptying and orocecal transit time was determined by use of the hydrogen breath test after ingestion of raffinose. During the control measurements, before the epidural analgesia, there were no differences in gastroduodenal pressure activity between the morphine and bupivacaine groups. Compared to epidural bupivacaine, epidural morphine significantly changed the pressure activity with a higher number of contractions in the duodenum, both during the fasted state and after food intake. Retrograde pressure activity was seen in the duodenum after epidural morphine but not after epidural bupivacaine. There were no significant differences in the pressure activity in the stomach after epidural morphine compared to epidural bupivacaine. Gastric emptying was delayed and orocecal transit time prolonged after epidural morphine. This study in volunteers showed that epidural morphine, compared to epidural bupivacaine, significantly changed the gastroduodenal motility, both during the fasted state and after food intake.

Adult↗
PubMed1989

Effects of epidural bupivacaine and epidural morphine on bowel function and pain after hysterectomy.

A comparison was made of the effects of continuous epidural analgesia with bupivacaine and intermittent epidural morphine on bowel function after abdominal hysterectomy. The duration of postoperative ileus was assessed as the time from the end of operation to the first postoperative passage of flatus and feces. Twenty-two patients were randomly allocated to two equal groups. An "epidural morphine" group received general anesthesia and epidural morphine for postoperative pain relief, and an "epidural bupivacaine" group was given combined general anesthesia and epidural anesthesia with 0.5% bupivacaine intraoperatively and epidural analgesia with 0.25% bupivacaine postoperatively. Epidural morphine or bupivacaine was given for 42 h postoperatively. Pain intensity (visual analog scale) was low in both groups, but lower (P less than 0.05) in the epidural bupivacaine group. The time to first passage of flatus was 22 +/- 16 h in the epidural bupivacaine group and 56 +/- 22 h in the epidural morphine group (P less than 0.001). The time to first postoperative passage of feces was shorter (P less than 0.05) in the former than in the latter 57 +/- 44 h vs 92 +/- 22 h). The patients of the epidural bupivacaine group started intake of oral fluids earlier (P less than 0.01) and to a greater extent (P less than 0.05) than those in the epidural morphine group. It is concluded that the duration of postoperative ileus after hysterectomy is shorter when epidural bupivacaine is given for postoperative pain relief than when this is achieved by epidural morphine.

Adult↗
PubMed1989

Postoperative pain relief and gastrointestinal motility.

Gastrointestinal motility is normally inhibited for 2-3 days after abdominal surgery. The methods used for postoperative pain relief may themselves also influence gastrointestinal function. Although parenteral and epidural administration of opioids delays gastric emptying and prolongs intestinal transit time, epidural anesthesia with local anesthetics does not influence gastrointestinal motility in volunteers. Clinical studies show that epidural anesthesia does not delay gastric emptying or prolong intestinal transit time as much as parenteral and epidural opioids. Therefore, for postoperative pain relief after abdominal surgery, epidural anesthesia with local anesthetics seems the best alternative to avoid or minimize adverse effects on gastric emptying and intestinal motility.

Anesthesia, Epidural↗
PubMed1989

Epidural analgesia with bupivacaine reduces postoperative paralytic ileus after hysterectomy.

This study was undertaken to compare the effects of postoperative bupivacaine epidural analgesia with those of intermittent injections of ketobemidone (a synthetic opioid) on postoperative bowel motility in patients who had had hysterectomies. The epidural group (N = 20) received continuous epidural anesthesia with bupivacaine postoperatively for 26-30 hours and the control group (N = 20) received intermittent injections of ketobemidone for postoperative pain relief. Postoperative bowel movements and propulsive colonic motility were estimated from the first passage of flatus and feces and by following radiopaque markers by serial abdominal radiographs. In the epidural group, the times for first passing of flatus (31 +/- 22 hours; mean +/- SD) and feces (70 +/- 44 hours) were significantly shorter than in the control group (flatus 58 +/- 14 hours and feces 103 +/- 26 hours). The average position of the markers was significantly more distally in the epidural group immediately after operation and the markers continued to move forward during the first postoperative day. In the control group, the markers did not move during this period. The results demonstrate that postoperative bowel peristalsis returned earlier in the patients given epidural analgesia with bupivacaine for pain relief than in patients given a narcotic.

Adult↗
PubMed1988

Effects of thoracic epidural analgesia with morphine or bupivacaine on lower oesophageal motility--an experimental study in man.

Lower oesophageal peristalsis and lower oesophageal sphincter (LOS) pressure during thoracic epidural analgesia (TEA) were studied in 20 healthy volunteers. After oesophageal manometric baseline recordings, 10 volunteers received 4 mg epidural morphine. The other ten received 0.5% bupivacaine epidurally in sufficient amounts to block the sympathetic innervation of the oesophagus. Thereafter oesophageal manometry was repeated. During epidural morphine oesophageal peristalsis, resting LOS pressure and the contraction of LOS after swallowing did not change, but the relaxation of the LOS in response to swallowing decreased significantly (P less than 0.01). Following TEA with bupivacaine, neither distal oesophageal peristalsis nor LOS pressure changed.

Adult↗
PubMed1988

Effects on gastric emptying of thoracic epidural analgesia with morphine or bupivacaine.

The effects of thoracic epidural analgesia on gastric emptying were evaluated in healthy fasting volunteers. In ten volunteers, 4 mg of epidural morphine were injected at the T4 level, and ten volunteers received thoracic epidural analgesia with 0.5% bupivacaine, the latter causing block of the sympathetic innervation to the stomach. Acetaminophen absorption was used as an indirect measure of the rate of gastric emptying. After establishment of the analgesia with bupivacaine, or 160 (110-185) minutes after the administration of epidural morphine, 1.5 g acetaminophen dissolved in water was ingested. Serum samples were taken at 15-minute intervals for 2 hours and serum acetaminophen concentrations were determined by an immunologic method. Control acetaminophen absorption studies without thoracic epidural analgesia were performed in all 20 subjects on another occasion. During epidural analgesia with morphine mean serum acetaminophen concentrations were lower (P less than 0.05), the maximum serum acetaminophen concentration was lower (P less than 0.01), the time taken to reach the maximum concentration was longer (P less than 0.02), and the area under the concentration time curve from 0 to 60 minutes was smaller (P less than 0.01) than in the control study. The corresponding values during epidural analgesia with bupivacaine did not differ from the control values. Four subjects with extremely delayed gastric emptying during epidural analgesia with morphine showed no delay in gastric emptying after receiving 4 mg morphine intramuscularly. Serum morphine concentrations were lower after epidural than after intramuscular morphine. In summary, 4 mg epidural morphine delayed gastric emptying. This was not a systemic effect of morphine. Thoracic epidural analgesia with bupivacaine had no influence on gastric emptying.

Absorption↗
PubMed1987

Circulatory effects of short-term hypercapnia during high thoracic epidural anaesthesia in elderly patients.

Circulatory changes and the degree of sympathetic block were evaluated in 15 elderly patients with high thoracic epidural anaesthesia (T1-T5). Bupivacaine 5-6 ml 0.5% was injected via an epidural catheter at the T3-level. The quality of the sympathetic block was determined with the Valsalva manoeuvre. Induced hypercapnia was used to quantify the degree of sympathetic block. Following thoracic epidural anaesthesia (TEA), cardiac output, stroke volume and arterial blood pressure decreased. During hypercapnia, heart rate and arterial blood pressure increased both before and after established TEA. Thus the block of the sympathetic innervation to the heart with a high TEA using 0.5% bupivacaine was not sufficient to prevent mobilization of circulatory reserves during sympathetic stimulation. The most likely explanation is considered to be the lack of neural block of the efferent nerves leading to the adrenal medulla and the peripheral vascular bed.

Aged↗
PubMed1987

Circulatory effects of short-term hypercapnia during thoracolumbar epidural anaesthesia.

In ten elderly patients subjected to extensive thoracolumbar epidural anaesthesia, circulatory changes were studied before and during sympathetic stimulation. Induced hypercapnia was used as a sympathetic stimulus. After establishment of the epidural anaesthesia, which extended from T1 to L2, there were decreases in heart rate, mean arterial blood pressure, cardiac output and systemic vascular resistance. Hypercapnia before the epidural block increased heart rate, arterial blood pressure and cardiac output, while hypercapnia after established epidural block induced only a slight increase in arterial blood pressure. The results indicate that in spite of an extensive epidural block, there are some "escaped" sympathetic nerve fibres that can be mobilized during sympathetic stimulation.

Aged↗
PubMed1987

Haemodynamic effects of intravenous bupivacaine during high thoracic epidural anaesthesia.

Administration of small doses of bupivacaine epidurally at the upper thoracic level will partially block the cardiac sympathetic nerves but not the sympathetic outflow via the adrenals. Local anaesthetics have direct systemic effects on the myocardium and the systemic circulation. The present study aimed to examine the effect of high thoracic epidural anaesthesia (TEA) in elderly patients, and to examine the effect of raising plasma bupivacaine concentrations in these patients, who had earlier had the sympathetic innervation of the heart blocked by thoracic epidural anaesthesia. Fifteen elderly patients scheduled for thoracotomy took part in the study. All received high thoracic epidural anaesthesia including the upper five thoracic dermatomes. When epidural block was established, ten patients received bupivacaine 3 mg/min intravenously for 20 min, while five patients received a corresponding volume of normal saline solution. After TEA was established, heart rate, mean arterial blood pressure and cardiac output decreased. When bupivacaine was given to these patients intravenously during the block, mean arterial blood pressure increased, while cardiac output decreased still more. The mechanisms behind these effects seem to be a direct constriction of the systemic blood vessels and a depressive effect on the myocardium, which was blocked from the influence of the cardiac sympathetic nerves by the high thoracic epidural block.

Aged↗
PubMed1987

Thoracolumbar epidural anaesthesia blocks the circulatory response to laryngoscopy and intubation.

Laryngoscopy and endotracheal intubation cause a stress reaction resulting in an increase in heart rate and systemic blood pressure. This haemodynamic response is considered to be due to a sympathetic discharge caused by stimulation of the upper respiratory tract. This stress reaction during laryngoscopy and endotracheal intubation was studied in patients with total thoracolumbar epidural anaesthesia (EDA). Nine patients with thoracolumbar EDA including at least the segments T1 to L2 were compared to seven patients without EDA during induction of general anaesthesia. The epidural anaesthesia was achieved with 2% mepivacaine with adrenaline. General anaesthesia was induced with thiopentone 4-5 mg/kg followed by 100 mg suxamethonium. The highest blood pressure value during the first 2 min after intubation was compared to the value immediately before intubation. The epidural anaesthesia caused a reduction of the mean arterial blood pressure (MAP) by 25%, and a reduction of the heart rate (HR) by 7%, but neither the induction with thiopentone nor the laryngoscopy and intubation caused any changes in mean arterial blood pressure or heart rate. However, in the control group MAP increased 29% and HR 16% following intubation. Thus, the T1-L2 epidural anaesthesia with 2% mepivacaine with adrenaline blocked the blood pressure reaction to laryngoscopy and intubation, and consequently the efferent sympathetic nervous system was completely blocked.

Adult↗
PubMed1986

Respiratory effects of high thoracic epidural anaesthesia.

The respiratory effects of high thoracic epidural anaesthesia (TEA) were studied in nine healthy volunteers by means of spirometry, nitrogen single-breath test and flow-volume loop. After the baseline measurements an epidural catheter was inserted at T4 level, and 5 ml of 0.5% bupivacaine were injected. This volume led to sensory block within dermatomes T1-T5. Total lung capacity, vital capacity and inspiratory capacity decreased slightly but significantly during TEA. Expiratory reserve volume was not affected. Maximal inspiratory flow at 50% VC decreased 24%. Maximal expiratory flow at 75% VC and peak expiratory flow were not changed. N2 difference during a constant flow rate of 0.5 l/s and forced expiratory volume in 1 s were not changed, which indicates that there were no changes of bronchial tone. The respiratory effects of high TEA in this study were caused by the motor block of the intercostal muscles.

Adult↗
PubMed1985

Circulatory changes during high thoracic epidural anaesthesia--influence of sympathetic block and of systemic effect of the local anaesthetic.

Circulatory changes during high thoracic epidural anaesthesia (TEA) were studied in nine healthy volunteers by means of echocardiography and systolic time intervals. The subjects also underwent a physical work test with bicycle ergometry. To evaluate the systemic effect of the local anaesthetic (bupivacaine), the same subjects were investigated 3 weeks later when a corresponding dose of the local anaesthetic was injected intramuscularly instead of epidurally. On the first occasion, after baseline measurements an epidural catheter was inserted at T4 level and 5 ml of 0.5% bupivacaine were injected. This volume led to sensory block within dermatomes T1-T5. On the second occasion all subjects received 8 ml of 0.5% bupivacaine intramuscularly. Heart rate (HR) and systolic blood pressure decreased during TEA, both at rest and during exercise. Following i.m. injection, HR decreased at rest but remained unchanged during exercise. The systolic blood pressure was not affected but the diastolic blood pressure increased during the exercise test. After administration of TEA, stroke volume (SV) decreased 22% and cardiac output (CO) 33%. Following i.m. injection of bupivacaine, SV decreased 8% and CO 20%. The pre-ejection period/left ventricular ejection time ratio increased 23% during TEA and 16% after i.m. injection. The results indicate that the circulatory changes did not seem to be caused entirely by the cardiac sympathetic block, but were due partly to the systemic effect of bupivacaine.

Adult↗
PubMed1984

Respiratory depression after epidural morphine--an experimental and clinical study.

This study was comprised of an experimental part (20 volunteers) and a clinical part (10 surgical patients). In the experimental part, the effects of either 2-, 4-, or 10-mg doses of epidural morphine on ventilatory responses to a standardized CO2 challenge were studied in healthy volunteers. In the clinical part, ventilatory responses to CO2 were evaluated in patients receiving 4 mg of epidural morphine for pain relief after gall bladder surgery. Naloxone infusion was given to five volunteers to determine whether ventilatory changes due to epidural morphine could be prevented. Using a nonrebreathing method, end-tidal PCO2 (PETCO2) and minute ventilation (tidal volume X frequency) were measured before and 1, 5, 8, 13, and 22 hr after epidural morphine injection. Ventilation was stimulated by 4% CO2 in 21% O2 and 75% N2. In the experimental study, a dose-related depression of ventilatory drive was seen after epidural morphine. After 2- and 4-mg doses, increases in PETCO2 were present up to 5 hr after injection with a corresponding reduction in minute ventilation. Ten mg of epidural morphine was followed by a significant reduction in minute ventilation and an increase in PETCO2 that started 1 hr after injection, peaked at 5 hr, and then remained almost unchanged for the next 17 hr. PETCO2 was higher and remained elevated longer in surgical patients than in volunteers given the same amount of epidural morphine (4 mg).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Postoperative epidural morphine, but not epidural bupivacaine, delays gastric emptying on the first day after cholecystectomy.

BACKGROUND AND OBJECTIVES: Gastric emptying is delayed during the first days after abdominal surgery. Studies with volunteers have shown that epidural morphine delays gastric emptying but epidural analgesia with bupivacaine does not. The aim of this study was to evaluate whether these differences in healthy volunteers are also found after cholecystectomy when epidural morphine or epidural bupivacaine is used for postoperative pain relief. METHODS: Eighteen healthy patients were randomly allocated into two groups. Nine patients received postoperative analgesia with epidural morphine and nine with thoracic epidural bupivacaine. Acetaminophen absorption was used as an indirect measure of the rate of gastric emptying, measured 22 hours after surgery and again 4 weeks later, so that each patient served as their own control. During epidural morphine, serum acetaminophen concentrations were lower, and the area under the concentration time curve from 0 to 60 minutes (AUC60) was smaller (p less than 0.02), the maximum serum acetaminophen concentration (Cmax) was lower (p less than 0.05), and the time taken to reach the maximum concentration (Tmax) was longer (p less than 0.01) compared to epidural bupivacaine. There were no statistically significant differences in AUC60, Cmax, and Tmax between the two groups during the control study. CONCLUSIONS: Postoperative gastric emptying was significantly delayed after epidural analgesia with morphine compared to thoracic epidural bupivacaine. Compared to the control situation, epidural bupivacaine did not influence gastric emptying.

Analgesia, Epidural↗