Post dural puncture headache in obstetric patients: experience from a West African teaching hospital.

BACKGROUND: This prospective, non-randomised study examined the frequency and severity of post dural puncture headache in 96 Ghanaian women who consented to spinal anaesthesia for caesarean section at the Korle Bu Teaching Hospital, Accra, Ghana. METHOD: Spinal anaesthesia was performed using 22-gauge (n = 22), 25-gauge (n = 46) or 26-gauge (n = 38) Quincke needles. Patients were followed up to determine the incidence and severity of post spinal headache. RESULT: The overall incidence of post dural puncture headache was 8.3%, but was significantly higher (33%) in patients in whom 22-gauge Quincke needles were used than in the other two groups (4% and 5% respectively: P = 0.003). Most patients rated their headache as mild to moderate on a 10-cm visual analogue scale. CONCLUSIONS: In view of the high incidence of headache and the need for treatment associated with the use of the 22-gauge Quincke needle, we recommend that this should not be used in the obstetric population. We are also aware that the incidence of post dural puncture headache could be further reduced by the use of small calibre pencil-point needles but these are currently very expensive and many obstetric units in developing countries may not be able to afford them.

Anaesthetic dilemma: spinal anaesthesia in an eclamptic patient with mild thrombocytopenia and an "impossible" airway.

We present our anaesthetic management of a 27-year-old woman with antepartum eclampsia, mild thrombocytopenia, difficult airway and clinical evidence of impending upper airway obstruction. She required urgent delivery by caesarean section, which was conducted uneventfully under spinal anaesthesia. We discuss the management conundrums presented by this case and why we chose spinal anaesthesia over other anaesthetic options.

Anaesthetic manpower development in West Africa.

Advances in surgery have been possible worldwide largely due to specialized manpower, innovations in modern anaesthetic techniques and drugs. Shortage of specialist manpower in anaesthesia has continued in West Africa despite various available local postgraduate training programmes. This paper examines the impact of the West African Postgraduate Medical College (WAPMC) training programme on anaesthetic manpower development in the West Africa subregion. Data collected from the records of the WAPMC revealed that from April 1992 to October 1996 a total number of 2,963 candidates attempted the primary examination of the various surgical faculties compared to 93 candidates for anaesthesia--a ratio of 32 prospective surgeons to one anaesthetist. The end point of the training produced 292 Fellows in the five-year period with only six in anaesthesia, i.e., 1 anaesthetist to 49 surgeons. Although the diploma programme of the same College produced 56 graduates in the study period, 53.6% of them were pursuing the Fellowship programme in tertiary institutions. Suggestions are proposed to redress the ever-widening gap between the number of specialist surgeons and anaesthetists in the West Africa subregion.

Comparison of propofol and methohexitone as an induction agent in anaesthesia for electroconvulsive therapy.

30 patients who received electroconvulsive therapy were anaesthetized with either Propofol or Methohexitone in a randomized cross-over study. Recovery times were shorter in those who received Propofol. The decrease in diastolic pressure after induction was greater with Propofol than with Methohexitone. There was a greater increase in the blood pressure after the electroconvulsive therapy in those who received Methohexitone. The duration of convulsion was similar for both agents.

Problems in extubation of endotracheal tube in anaesthesia in the West African sub-region.

Three Retrospective Case Studies of the problems often faced with extubation of endotracheal tube during routine endotracheal anaesthesia is reported to alert anaesthetists about endotracheal tubes with intact and inflatable cuffs which could pose potential dangers to safety of patients in Anaesthetic practice, especially in the West-African Sub-region because of our practice of re-using both re-usable and disposable endotracheal tubes.

Ranitidine and sodium citrate as prophylaxis against acid aspiration syndrome in obstetric patients undergoing caesarean section.

The efficacy of a single oral dose of 0.3M of sodium citrate alone as a prophylaxis against acid aspiration syndrome in obstetric patients undergoing LSCS (elective and emergency) was compared with that of intravenous ranitidine. One group of patients was given 30 ml of 0.3M sodium citrate orally just before the induction of anaesthesia while the other group was given 50mg of ranitidine intravenously together with the 30ml of 0.3M sodium citrate. This was done for both the elective and the emergency groups of patients. There was no significant difference in the mean pH of the gastric aspirate obtained from those given sodium citrate alone and those given sodium citrate and ranitidine in either the elective or the emergency group. However, in the emergency group, those who were given sodium citrate alone tend to have a larger volume of gastric aspiration when compared with those given ranitidine together with the sodium citrate. There were significantly more patients with gastric aspirates of more than 25ml in the emergency group to which sodium citrate alone was given. It would appear that supplementing an intravenous dose of ranitidine with the oral dose of sodium citrate is useful in emergency LSCS as a prophylaxis against acid aspiration syndrome.

Difficult intubation stylohyoid ligament calcification.

Intubation was difficult and traumatic in a 40-year-old patient presented for emergency oesophagoscopy because the diagnosis of stylohyoid ligament calcification was not suspected. High probability of stylohyoid ligament calcification should be suspected when there is difficulty in lifting the epiglottis and fibre-optic laryngoscopy is suggested as the best way to tackle this problem to prevent trauma and possible risk of regurgitation and aspiration especially in emergency situation.

The use of single dose of sodium citrate as a prophylaxis against acid aspiration syndrome in obstetric patients undergoing caesarean section.

The effectiveness of sodium citrate as a prophylaxis against acid aspiration syndrome was studied in 3 groups of obstetric patients. Group I was the control group which consisted of 20 patients in established labour who were not likely to require caesarean section. No antacid had been given to these patients. Group II consisted of 20 patients who underwent elective caesarean section, while Group III consisted of another 20 patients who underwent emergency caesarean section. Group II and III were given 30ml of 0.3M sodium citrate as soon as they arrived in the operation theatre. The gastric content was aspirated after the induction of anaesthesia and at the end of surgery just before extubation. The volume was measured and a sample sent for pH analysis. Sodium citrate was found to increase the gastric pH significantly in both Group II and III patients when compared with Group I patients who underwent emergency caesarean section. We conclude that 30ml of 0.3M sodium citrate is effective in increasing gastric pH though it tends to be associated with an increase in gastric volume.

Effects of epinephrine on firing characteristics of two functionally different types of carotid baroreceptors.

Sympathetic stimulation and catecholamine exposure have been shown to sensitize the arterial baroreceptors, but the extent or importance of this effect is not known. We performed this study to investigate the effects of sympathetic feedback on the carotid sinus baroreceptors, specifically examining the effect of the stimulation on the two different functional types of baroreceptors characterized in an earlier study. The existence of two baroreceptor function-response curves has suggested that the roles of the two functionally different baroreceptors may not be the same. If true, the effects of epinephrine exposure on baroreceptor firing characteristics may contribute to differential roles played by each baroreceptor type in the control of blood pressure. Single-fiber baroreceptor activity from a vascularly isolated carotid sinus was recorded during slow increases in carotid sinus pressure before and during exposure to epinephrine (10(-8) to 10(-6) M). Baroreceptor firing characteristics were determined from function curves plotting carotid sinus pressure versus nerve activity, with curve-fitting analysis of the hyperbolic type I and sigmoidal type II baroreceptor curves used to obtain threshold (Pth) and saturation (Psat) pressures, threshold (Fth) and saturation (Fsat) firing rates, and sensitivity (slope) for each baroreceptor before and during epinephrine exposure. The possible mechanisms of observed changes were examined using our previously published baroreceptor computer model. Epinephrine exposure was found to significantly increase sensitivity, Fth, and Fsat of both types of baroreceptors, with a relatively greater effect on type I sensitivity and on type II Fth and Fsat. Epinephrine also was found to increase the level of spontaneous discharge for type II baroreceptors.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of flunitrazepam (Rohypnol) on awareness during anaesthesia for caesarean section.

The incidence of awareness was compared in three groups of patients undergoing elective or emergency Caesarean section, using pethidine alone or pethidine plus flunitrazepam (Rohypnol), as adjuvants to nitrous oxide: oxygen, muscle relaxant technique of general anaesthesia. The use of 0.03 mg/kg body weight of flunitrazepam was associated with a low incidence (4%) of awareness, cardiovascular stability, postoperative sedation and anterograde amnesia. The reduced incidence of awareness is probably due to increased depth of anaesthesia and anterograde amnesic effect produced by the drug.

Effects of isoflurane on the baroreceptor reflex.

The baroreceptor reflex has been found to be attenuated during anesthesia, but the effects of the relatively new anesthetic, isoflurane, on baroreflex function have not been examined thoroughly. This study was performed to determine the effects of isoflurane on each component of the baroreceptor reflex arc, including the receptors, afferent and efferent nerve pathways, central integratory centers, peripheral ganglia, and the heart. Baroreflex effects on heart rate initiated by systemic pressure changes were examined in conscious and anesthetized dogs (1.3% and 2.6% isoflurane). The effects on individual components of the reflex arc were determined by examining carotid sinus baroreceptor afferent activity, sympathetic efferent nerve activity, and heart rate response to direct sympathetic and parasympathetic efferent nerve stimulation in anesthetized dogs. Preganglionic and postganglionic nerve activities were recorded simultaneously during baroreflex activation to determine ganglionic effects of isoflurane. Baroreflex-induced changes in heart rate were not depressed significantly until 2.6% isoflurane if blood pressure changes due to anesthetic administration were prevented. Significant decreases in baseline sympathetic efferent nerve activity were found at 1.3% and 2.6% isoflurane, with depression of postganglionic activity significantly greater than preganglionic activity at 2.6% isoflurane, indicating a ganglionic effect of isoflurane. Cardiac chronotropic responses to direct stimulation of sympathetic and vagal fibers were attenuated significantly by isoflurane, with sympathetic stimulation showing the greater sensitivity to the anesthetic. Carotid baroreceptor afferent activity was increased by isoflurane, and this sensitization of the baroreceptors appeared to contribute to the decreased levels of sympathetic tone. Therefore, although isoflurane was found to alter the baroreceptor reflex through its effects at multiple sites of the baroreflex arc, significant depression of the cardiac chronotropic component of the reflex was seen only at 2.6% isoflurane.

Extent and mechanism of halothane sensitization of the carotid sinus baroreceptors.

The present study was performed to determine the extent and mechanism of carotid sinus baroreceptor sensitization due to halothane in an isolated, denervated carotid sinus in anesthetized dogs (thiopental 25 mg/kg; 5 mg X kg-1 X h-1, maintenance dose). Efferent sympathetic nerves to the sinus were sectioned to eliminate the contribution of these fibers to any sensitization observed. Halothane (H) administration was localized to the carotid sinus by an isolated perfusion system. The perfusion system was used to make standardized sine wave changes in carotid sinus pressure. Carotid sinus afferent nerve activity from single or few-fiber nerve preparations was recorded during carotid sinus pressure changes and the slopes of nerve activity versus carotid sinus pressure were used to determine the gain, or sensitivity, of the baroreceptors. The addition of 0.75% H and 1.5% H to the sinus perfusion produced a dose-dependent sensitization of the baroreceptors. A greater increase in carotid sinus afferent nerve activity for a given increase in sinus pressure was used as an indication of an increase in receptor sensitivity, or sensitization. In the presence of sodium nitroprusside, given in doses to maximally dilate the sinus prior to H administration, only 1.5% H produced baroreceptor sensitization. This suggests the changes in sinus wall tension due to halothane may have contributed to the sensitization seen during H administration. The remaining sensitization at 1.5% H was eliminated in the presence of nitroprusside and 7.5 mM Ca++. This remaining sensitization therefore appears to be Ca++-related and may be due to direct effects of H on the baroreceptors.

Post-suxamethonium pains in Nigerian surgical patients.

Contrary to an earlier report by Coxon, scoline pain occurs in African negroes. Its incidence was determined in a prospective study involving a total of 100 Nigerian patients (50 out-patients and 50 in-patients). About 62% of the out-patients developed scoline pain as compared with about 26% among the in-patients. The abolition of muscle fasciculations (by 0.075mg/kg dose of Fazadinium) did not influence the occurrence of scoline pain. Neither the type of induction agent (Althesin or Thiopentone) nor the salt preparation of suxamethonium used (chloride or bromide), affected the incidence of scoline pain.

Difficult laryngoscopy and tracheal intubation due to calcified stylohyoid ligaments.

Two cases of difficult laryngoscopy and tracheal intubation caused by calcified stylohyoid ligaments are presented. Neither patient exhibited a skin crease over the hyoid bone. It is suggested that inability to lift up the epiglottis from the posterior pharyngeal wall be taken as a more useful sign of this condition than the presence of the skin crease.