Ondansetron attenuates the decrease in blood pressure due to spinal anesthesia in the elderly: a double blind, placebo-controlled study

BACKGROUND

Ondansetron was effectively used to prevent spinal anesthesia-induced hypotension in the general population and women anesthetised for cesarean section. The aim of this study was to test the hypothesis that blocking type 3 serotonin receptors with intravenous ondansetron administration reduces hypotension and bradycardia induced by spinal anesthesia in elderly patients.

METHODS

Fifty-three patients participated in the study with 26 in the ondansetron group (received 8 mg intravenous ondansetron) and 27 in the placebo group (received 0.9% NaCl solution). The heart rate and arterial blood pressure were measured every 5 minutes after spinal anaesthesia, which was performed with 2.5 to 3 mL of 0.5% hyperbaric bupivacaine solution.

RESULTS

Decreases in both the heart rate and mean systolic, as well as diastolic, arterial pressure compared to the baseline values were noted in both groups. The minimum diastolic and mean blood pressure values obtained over a 20-minute observation period were significantly higher in the ondansetron group. There were no significant differences in the systolic blood pressure and heart rate values between the groups.

CONCLUSION

Administration of intravenous ondansetron prior to spinal anesthesia in geriatric patients attenuates the drop in the diastolic and mean arterial pressure without substantially affecting the systolic blood pressure.

The influence of anesthesia on cardiac repolarization

The drugs and techniques used in contemporary anaesthesia may provoke numerous side effects, including cardiac rhythm disturbances. The prolongation of the repolarization time, reflected by the QT interval in a surface electrocardiogram, is one of the mechanisms that lead to the occurrence of arrhythmias. In the paper, we present the primary mechanism that is responsible for QT interval prolongation and subsequent torsade de pointes ventricular tachycardia. The influence of anesthetics, regional anesthesia and perioperative supportive therapy on cardiac repolarization is described.

The effect of intravenous lidocaine on QT changes during tracheal intubation

Laryngoscopy and tracheal intubation may provoke changes of cardiac repolarisation. The aim of this study was to assess the effect of intravenous lidocaine on the ECG changes induced by laryngoscopy and tracheal intubation. Forty-three female patients were randomly allocated to receive lidocaine (1.5 mg.kg(-1)) or placebo immediately after induction of anaesthesia and changes in the ECG and arterial blood pressure were recorded. Correction of QT interval was calculated using Bazett's formula (QTcb), Fridericia's correction (QTcf), and Framingham formula (QTcF). Transmural dispersion of repolarisation (TDR) was determined as Tpeak-Tend time. There were no changes in the QTc value in the lidocaine group. In the placebo group, significant increases in QTcb, QTcf and QTcF values were observed after intubation compared to either control measurements or to comparative measurements in the lidocaine group. There were no significant differences in TDR either between or within the groups. Lidocaine diminishes prolongation of QTc, induced by tracheal intubation but there is no effect of intubation on TDR.

Total spinal anaesthesia as a complication of local anaesthetic test-dose administration through an epidural catheter

We describe a case of total spinal anaesthesia, which occurred after a 3-ml lignocaine (20 mg ml(-1)) test dose was administered through an epidural catheter in a 79-year-old patient scheduled for gastrectomy under combined general and epidural anaesthesia. The surgery was postponed, and the patient required admission to the intensive therapy unit. Spinal MRI from the total spinal cord did not reveal any pathology. During the next 24 h the patient recovered and after 11 days was successfully operated on under general anaesthesia. No late complications followed. We presume that during placement, the epidural catheter had migrated to the spinal canal as a result of technical difficulties. Although controversial, we consider that administering a standard test dose of local anaesthetic via an epidural catheter is recommended, especially in high-risk patients and when epidural space identification or catheter placement poses technical difficulties. A test dose of local anaesthetic does not fully prevent complications.

Is prolongation of the QTc interval during isoflurane anaesthesia more prominent in women pretreated with anthracyclines for breast cancer? †

BACKGROUND

Inhalation anaesthetics and anthracycline chemotherapeutic drugs may both prolong the QT interval of the electrocardiogram. We investigated whether isoflurane may induce or augment QTc prolongation in patients who had previously received cancer chemotherapy including anthracycline drugs.

METHODS

Forty women undergoing surgery for breast cancer were included in the study. They were divided into two groups: (A) women previously treated with anthracyclines (n=20); and (B) women not treated with antineoplastic drugs (n=20). All patients received a standardized balanced anaesthetic in which isoflurane 0.5 vol% was used. The QT and corrected QT intervals were measured before anaesthesia, after induction and tracheal intubation, after 1, 5, 15, 30, 60 and 90 min of anaesthesia, and during recovery.

RESULTS

In both groups we observed a tendency to QTc prolongation, but statistically significant differences among baseline values and values observed during isoflurane-containing anaesthesia were seen only in group A. During anaesthesia, significant differences in QTc values between the two groups were observed.

CONCLUSION

In female patients pretreated with anthracyclines for breast cancer, the tendency to QTc prolongation during isoflurane-containing general anaesthesia was more strongly expressed than in patients without previous chemotherapy.

Administration of clemastine--H1 histamine receptor blocker in the prevention of haemodynamic disorders after protamine sulfate administration in patients subjected to coronary artery bypass grafting in extracorporeal circulation

INTRODUCTION

Adverse effects of protamine administration after CPB: fall in arterial blood pressure and pulmonary hypertension are still a source of problems. CPB and protamine administration are both accompanied by increased histamine levels in blood. The aim of this study was to examine if clemastine can accelerate the normalisation of arterial blood pressure during the protamine administration after CPB during CABG operations.

MATERIAL AND METHODS

Fifty three patients subjected to CABG operations were studied. Control group (n = 27) did not receive clemastine, Clemastine group (n = 26) received 2 mg i.v. clemastine, before CPB. After CPB were completed, patients were given protamine (heparin to protamine ratio--1:1.5) within 7 minutes, through peripheral vein. Changes in arterial blood pressure from the beginning of protamine administration to 2.5, 5, 7.5, 10, 15, and 30 minutes thereafter, as well as heart rate, CVP, doses of inotropic drugs and vasodilators were compared between the groups.

RESULTS

No difference in heart rate, CVP, doses of inotropic drugs and vasodilators between the group was noted. An increase in arterial blood pressure 5, 7.5, 10, and 15 minutes after the beginning of the protamine administration were greater in clemastine group than in control group. Groups were comparable with regard to surgical procedures and doses of anaesthetic drugs. It is now known that protamine exerts a negative effect on cardiac contractility either through a decrease in coronary perfusion pressure (vasodilatation), or through a direct toxic effect on cardiac muscle. The administration of clemastine before CPB can reduce peripheral vasodilatation and capillary leak related to histamine release during CPB. In the clemastine group, faster increase in arterial blood pressure toward a physiologic range was observed. We conclude that administration of clemastine is connected with the normalization of ABP during and after protamine reversal of heparin coagulation during CABG operations.

Thermographic assessment of stellate ganglion block effectiveness during cardiosurgical procedures

The study present thermographic assessment of the effectiveness of temporary stellate blockade performed during cardiosurgical procedures. The assumption behind this method was the increase in the temperature of upper extremity on the side of blockade, due to the broadening of arterial bed.

MATERIAL AND METHOD

The study was conducted on a group of 30 patients (21 men and 9 women) operated due to coronary disease involving three vessels. Mean age of the patients was 53 years. After introduction of anaesthesia blockade were performed with 2 ml 2% lignocainum and 8 ml 0.5% bupivacaine solution using peratracheal approach. Blockade effectiveness was assessed on the basis of images obtained in thermovisual camera, comparing the temperatures of upper extremity before and within 15 minutes after performing the blockade. Free blood outflow from radial artery, its diameter and length were also evaluated. The results obtained were subject to statistical analysis.

RESULTS

Twenty-three patients (76.6%) displayed the increase in the temperature of upper extremity by 1-3 degrees C. Free blood outflow from radial artery was greater in this group than in the remaining patients.

CONCLUSIONS

Thermography is a useful method for the assessment of stellate blockade effectiveness. Effective blockade results in the increased blood flow in radial artery.

[A case of purulent peritonitis treated by the "in the open" method]

A 35-year-old man is described who had diffuse purulent peritonitis resulting from duodenal ulcer perforation. Due to the extent and progression of inflammatory changes the abdominal wall was not sutured and the peritoneal cavity was repeatedly controlled. The patient was operated on as an emergency case in the 49th hour after appearance of clinical symptoms. About 5 1 of pus was found in the peritoneum, with fibrin-caused adhesions between intestinal loops with their segmental occlusion. The hole in the duodenal wall was sutured with single sutures, the abdominal cavity was washed with about 10 1 of. 0.02% hibitane solution. Further controls of the abdominal cavity were done on days 3 and 5 after operation removing a small abscess between intestinal loops on the 3rd day and reducing recent ileus due to gumming up of loops on days 3 and 5. During the last control the Child-Philips procedure was done in anticipation of another ileus. After finding of complete absence of inflammatory peritoneal changes the abdominal wall was closed ith sutures. The patient was discharged on the 30th day with a healed surgical wound. Control examination after 7 months showed a very good general condition and linear scar at the site of duodenal perforation.