Effect of delayed supine positioning after induction of spinal anaesthesia for caesarean section

BACKGROUND: The study tested the hypothesis that the incidence of hypotension during spinal anaesthesia for caesarean section is less in parturients who remain in the sitting position for 3 min compared with parturients who are placed in the modified supine position immediately after induction of spinal anesthesia. METHODS: Spinal anaesthesia was induced with the woman in the sitting position using 2.8 ml hyperbaric bupivacaine 0.5% at the L(3-4) or L(2-3) interspace. Ninety-eight patients scheduled for elective caesarean section under spinal anaesthesia were randomised to assume the supine position on an operating table tilted 10 degrees to the left (modified supine position) immediately after spinal injection (group 0, n=52) or to remain in the sitting position for 3 min before they also assumed the modified supine position (group 3, n=46). Isotonic saline 2-300 ml was given intravenously over 15 min before spinal injection followed by 15 ml/kg over 15-20 min after induction of spinal anaesthesia. If the systolic blood pressure decreased to less than 70% of baseline or to less than 100 mmHg or if there was any complaint of nausea, ephedrine was given in 5 mg boluses intravenously every 2 min. RESULTS: The blood pressure decreased significantly in both groups following spinal injection (P<0.001). Blood pressure variations over time differed significantly between the two groups (P<0.05). However, the incidence of maternal hypotension before delivery was similar in the two groups. The difference was caused by the time to the blood pressure nadir being significantly shorter in group 0 compared with group 3 (9.1+/-4.5 min vs. 11.7+/-3.7 min, P<0.01). Similar numbers of patients received rescue with ephedrine before delivery: 35 (67%) in group 0 vs. 26 (57%) in group 3 (NS). The mean total dose of ephedrine before delivery was 10.9 mg in group 0 vs. 9.2 mg in group 3 (NS). There were no differences in neonatal outcome between the two groups. CONCLUSION: At elective caesarean section, a 3-min delay before supine positioning does not influence the incidence of maternal hypotension after induction of spinal anaesthesia in the sitting position with 2.8 ml of bupivacaine 0.5% with 8% dextrose.     

Thromboembolic deterrent stockings fail to prevent hypotension associated with spinal anaesthesia for elective caesarean section

This study was carried out to determine whether the use of thrombo-embolic deterrent (TED) stockings, in combination with an intravenous crystalloid preload, would prevent hypotension following spinal anaesthesia for caesarean section. Fifty parturients undergoing elective caesarean section under spinal anaesthesia were randomly allocated into two groups. TED stockings were applied to the study group 1 h before spinal anaesthesia but none were applied to the control group. Both groups received a crystalloid preload of 15 ml kg(-1) over 15 min before spinal injection. Significant hypotension, defined as an absolute value of systolic arterial pressure (SAP) of less than 90 mmHg and a decrease of more than 20% from baseline SAP was treated with 3 mg bolus of ephedrine as required. The difference in SAO between the two groups was not statistically significant. In the control group, 80% of parturients required ephedrine as opposed to 56% in the TED group; a difference that was also not statistically significant.     

Spinal versus epidural anesthesia for cesarean delivery in severe preeclampsia: a prospective randomized, multicenter study

In this randomized, multicenter study we compared the hemodynamic effects of spinal and epidural anesthesia for cesarean delivery in severely preeclamptic patients. The epidural group (n = 47) received 2% lidocaine with epinephrine 1:400,000, 18-23 mL, followed by 3 mg of morphine after delivery. The spinal group (n = 53) received 2.2 mL of 0.5% hyperbaric bupivacaine plus 0.2 mg morphine. We hypothesized that the lowest MAP (mean arterial blood pressure, the primary outcome) during the delivery period would have to be at least 10 mm Hg less in the spinal group to be of clinical importance. We found that there was a statistically significant difference in MAP, with more patients in the spinal group exhibiting hypotension (P < 0.001). Although the incidence of hypotension (systolic arterial blood pressure, SAP < or =100 mm Hg) was more frequent in the spinal group than in the epidural group (51% versus 23%), the duration of significant hypotension (SAP < or =100 mm Hg) was short (< or =1 min) in both groups. There was more use of ephedrine in the spinal group than in the epidural group (median, 6 versus 0 mg) but hypotension was easily treated in all patients. Neonatal outcomes assessed by Apgar scores and the umbilical arterial blood gas analysis were similar in both groups. Adverse neonatal outcomes (5-min Apgar score < 7 and umbilical arterial blood pH < 7.20) were found in only 2 premature newborns (weight < 1500 g) who were born without maternal hypotension after regional anesthesia. We conclude that the results of this large prospective study support the use of spinal anesthesia for cesarean delivery in severely preeclamptic patients.     

Effects of hypertonic 75 mg/ml (7.5%) saline on extracellular water volume when used for preloading before spinal anaesthesia

Background: Prevention of hypotension during spinal anaesthesia is commonly achieved using fluid preloading. This may result in a substantial amount of excess free water retained in the body after spinal anaesthesia. We aimed to evaluate the effects of 7.5% hypertonic saline on extracellular water volume and haemodynamics when used for fluid preloading before spinal anaesthesia.
Methods: This randomised double-blind study evaluated the effects of 75 mg/ml (7.5%) hypertonic saline (HS) on extracellular water volume and haematocrit in patients undergoing arthroscopy or other lower limb surgery under spinal anaesthesia. Amounts of 1.6 ml/kg of HS (20 patients) or 13 ml/kg of 9 mg/ml normal saline (20 patients) were administered for preloading before spinal anaesthesia with a 10 mg dose of 0.5% hyperbaric bupivacaine. Etilefrine was administered in order to maintain mean arterial pressure (MAP) at 80% of its baseline value. Whole-body impedance cardiography-derived cardiac index (CI) and extracellular water (ECW) were measured.
Results: There were no significant differences in demographic data or in the number of blocked segments. ECW remained similar in both groups despite the much smaller amount of infused free water in the HS group. There were no significant differences between the groups in CI values during the study. The amount of etilefrine administered was similar in the treatment groups. Dilution of haematocrit was also similar in both groups.
Conclusion: Hypertonic 75 mg/ml (7.5%) saline is an alternative for preloading before spinal anaesthesia in situations where excess free water administration is not desired. It is effective in small doses of 1.6 ml/kg, which increase the extracellular water, plasma volume and cardiac output, and thus maintain haemodynamic stability during spinal anaesthesia.     

A comparison of spinal and epidural anaesthesia for hip arthroplasty

Spinal and epidural anaesthesia were compared in 65 patients undergoing hip arthroplasty, with regard to the degree of sensory and motor blockade, cardiovascular effects, operating conditions, the dose of propofol required to produce satisfactory hypnosis, and complications. Epidural anaesthesia was successful in 30 patients using an initial dose of 15 ml of 0.5% bupivacaine, and spinal anaesthesia in 32 patients, using 4 ml 0.5% isobaric bupivacaine. The two techniques were similar with regard to the level of sensory blockade (T8), degree of hypotension and perioperative haemorrhage. Differences occurred in the degree of motor blockade (mean Bromage score of 1 in the spinal group vs 3.86 in the epidural group) (P less than 0.05), time to achieve maximal cephalad spread (13 min in the spinal group vs 21 min in the epidural group) (P less than 0.05) and the dose of propofol required to produce adequate hypnosis (1.95 mg.kg-1.hr-1 in the spinal group vs 2.89 mg.kg-1.hr-1 in the epidural group) (P less than 0.05). Only seven patients required urethral catheterization in this spinal group compared with 14 in the epidural group (P less than 0.05). Spinal anaesthesia also proved advantageous by providing better operating conditions for the surgeon, with a lower incidence of patient movement.     

Prevention of hypotension during spinal anaesthesia for caesarean section

Twenty-six parturients scheduled to receive spinal anaesthesia for caesarean section were randomized to receive either isotonic saline 750 ml plus 20 ml/kg (group A) or 750 ml plus 500 ml (group B) before subarachnoid administration of bupivacaine 13 mg. Ephedrine 0.15 mg/kg i.v. followed by an infusion 0.4 mg.kg(-1) h(-1) were then administered in group B. In both groups ephedrine 10 mg/min i.v. was given if the mean arterial blood pressure decreased more than 10 mmHg. Despite the fluid preload and large doses of ephedrine noted {median (range), group A 30 mg (10-80), group B 92 mg (25-194)}, hypotension, sometimes accompanied by nausea, still occurred. Mean maternal arterial was significantly lower in group A than in group B 5-10 min after induction of spinal anaesthesia (P < 0.05). There was no difference in the frequency of nausea or vomiting, Apgar score, or pH in umbilical cord blood. One neonate in group A and 2 in group B were acidotic. In conclusion, a reduced volume loading could be compensated with an increased ephedrine administration after induction of spinal anaesthesia, without increasing the incidence of hypotension or other maternal or neonatal complications. However, the fluid volumes and/or ephedrine doses used were not sufficient to prevent hypotension altogether.     

Hydroxyethylstarch 10% is superior to Ringer’s solution for preloading before spinal anesthesia for Cesarean section

PURPOSE: To compare the preloading effect of 500 ml hydroxyethylstarch (HES) 10% with 1 L Lactated Ringer's solution (LR). METHODS: In 40 healthy women undergoing elective Cesarean section HES, 500 ml (n = 20), or LR, IL (n = 20), was administered during 10 min before spinal anesthesia. The incidence of hypotension, (systolic blood pressure < 80% of baseline and < 100 mm Hg), and the amount of ephedrine used to treat it were compared. Also, the incidence of nausea and/or vomiting were recorded. Neonatal outcome was assessed using Apgar scores and umbilical venous and arterial blood gases. RESULTS: The incidence of hypotension was higher in the LR than in HES group (80% vs 40%). Mean minimum systolic blood pressure was lower in the LR than in the HES group (86.1 +/- 12.7 mm Hg vs 99.6 +/- 9.7 mm Hg P < 0.05). Systolic blood pressure < 90 mmHg occurred in two of 20 patients (10%) who received HES vs 11 of 20 patients (55%) who received LR (P < 0.05). More doses of ephedrine were required to treat hypotension in the LRthan in the HES group (35.3 +/- 18.4 mg vs 10.6 +/- 8.6 mg; P < 0.05). The incidence of nausea and/or vomiting was lower in the HES than in the crystalloid group. Neonatal outcome was good and similar in both groups. CONCLUSION: Preloading patients undergoing elective Cesarean section with 500 ml HES 10%, decreases the incidence and severity of spinal-induced hypotension more than preloading with 1 L of LR solution.     

Effect of injection rate on hypotension associated with spinal anesthesia for cesarean section

Maternal hypotension is a common problem during cesarean section under spinal anesthesia. We evaluated in a prospective observational study the influence of injection speed on maternal hypotension. Hyperbaric bupivacaine 10 mg, sufentanil 2 microg and morphine 200 microg (total volume 4 mL) were injected either quickly (<15 s) or slowly (=120 s) in 50 women scheduled for elective cesarean section. Hypotension (systolic arterial pressure (SAP) <100 mmHg or <70% of baseline) was promptly treated with 5 mg ephedrine boluses. Slow injection significantly reduced the incidence of hypotension (68% in the 120 s group and 92% in the other, P =0.03). In addition, onset of hypotension was delayed, had a shorter duration and required less ephedrine for hypotension in the 120 s group (11.6 mg vs. 19.6 mg, P =0.019). Anesthesia was satisfactory for all women. We conclude that a 2 mL/min injection rate may be a simple and effective way to reduce the incidence and severity of hypotension during cesarean section under spinal anesthesia.     

Xenon anaesthesia may preserve cardiovascular function in patients with heart failure

BACKGROUND: The hypothesis that xenon anaesthesia provided haemodynamic stability was tested in patients with heart failure in a prospective, randomized, single-blind design. METHODS: Twenty-six patients scheduled for implantation of a cardioverter-defibrillator (ICD) received xenon 60-65% in oxygen (xenon group, n = 12) or propofol 3 mg/kg/h (propofol group, n = 14), both combined with remifentanil 0.2 microg/kg/min. After induction of anaesthesia with etomidate and remifentanil, heart rate (HR), mean arterial pressure (MAP) and left ventricular ejection fraction (LVEF) were recorded. After 60 min of propofol or xenon anaesthesia, the same parameters were recorded. RESULTS: While HR decreased in both groups, MAP was unchanged with xenon (73 vs. 76 mmHg) and decreased with propofol (from 78 to 64 mmHg, P < 0.02). LVEF was stable in both groups [32% vs. 37%, xenon (NS), and 30% vs. 34%, propofol (NS)]. Preload, as measured by end-diastolic volume (EDV), did not change (66 vs. 63 ml with xenon; 79 vs. 81 ml with propofol, both NS). Afterload, as determined by end-systolic pressure-volume product (ESPV), decreased with propofol (6760 vs. 4920 ml mmHg) but not with xenon (4060 vs. 3780 ml mmHg, P < 0.01 between groups). CONCLUSION: With propofol, MAP is reduced and LVEF is not increased in spite of reduced afterload. In contrast, MAP and LVEF are maintained with xenon.     

The effect of 10 degrees head-up tilt in the right lateral position on the systemic blood pressure after subarachnoid block for Caesarean section

Forty women presenting for elective Caesarean section under spinal anaesthesia were randomly assigned to have anaesthesia induced in the right lateral position either in the horizontal position or with 10 degrees head-up tilt. Hyperbaric bupivacaine 2 ml 0.5% with 0.1 mg of morphine was injected intrathecally before the parturients were placed in the supine position with 15 degrees left lateral tilt. Blood pressure and heart rate were monitored every minute and the sensory level (loss of sharp sensation to pinprick) was monitored every 3 min until clamping of the umbilical cord. Ephedrine 6 mg was given every minute that the systolic blood pressure decreased below 90 mmHg. The mean systolic blood pressure during the first 5 min after induction of spinal anaesthesia was lower in the control group compared to the tilted group (99 mmHg vs. 109 mmHg; p = 0.043). The upper limit of block was higher in the control group compared to the tilted group (p = 0.002). The use of 10 degrees head-up tilt resulted in a reduced incidence of hypotension initially and less extensive sensory block.     

Anaesthesia for 1131 patients undergoing proximal femoral fracture repair: a retrospective, observational study of effects on blood pressure, fluid administration and perioperative anaemia

Intra-operative hypotension is a frequent occurrence during anaesthesia for hip fracture surgery in older patients with co-morbidities. We analysed retrospective data from the Brighton Hip Fracture Database to determine the intra-operative fall in systolic blood pressure, and the incidence of absolute (lowest systolic blood pressure < 90 mmHg) and relative (> 20% fall in systolic blood pressure from baseline) hypotension during general or spinal anaesthesia among 1131 non-consecutive patients with hip fracture. General anaesthesia for 489 patients (43.2%) produced a greater mean (SD) fall in systolic blood pressure than spinal anaesthesia for 578 patients (51.1%): 34.2% (13.0%) vs 29.7% (10.8%), respectively (p < 0.0001), mean difference 4.5% (95% CI 3.1-5.9%), and was associated with greater mean (SD) intra-operative fluid administration (1555 (801) ml vs 1375 (621) ml, respectively, p < 0.0001). We observed a correlation between the volume of subarachnoid hyperbaric bupivacaine 0.5% and fall in systolic blood pressure (p = 0.004): compared with patients receiving > 1.5 ml (n = 463), fewer patients receiving ≤ 1.5 ml bupivacaine 0.5% (n = 97) experienced episodes of absolute (31.1% vs 11.3%, p < 0.0001) or relative (83.9% vs 26.8%, p < 0.0001) hypotension. Both mean (SD) intravenous fluid administration (1097 ml (439) vs 1431 ml (638), p < 0.0001) and mean peri-operative fall in haemoglobin concentration (2.1 (1.8) g.dl(-1) vs 2.6 (1.7) g.dl(-1), p = 0.009) were lower in the low-dose spinal group. If these data are confirmed by other researchers, intra-operative hypotension (and consequent haemodilution secondary to reactive fluid administration) in this patient group may be reduced by the simple expedient of administering more cautious general anaesthesia, or reduced volumes of subarachnoid local anaesthetic.     

Intravenous ketamine for prevention of severe hypotension during spinal anaesthesia

Spinal block causes paralysis of preganglionic sympathetic fibres, while ketamine induces activation of the sympathetic nervous system. Hypotension is a frequent complication during spinal anaesthesia and is associated with an increased risk of postoperative mortality. The aim of our study was to compare circulatory changes in patients who received either fentanyl or ketamine during spinal anaesthesia. Thirty patients (ASA I-III) scheduled to undergo spinal anaesthesia for osteosynthesis of hip fractures were allocated to receive either ketamine or fentanyl intravenously during the procedure. Immediately before anaesthesia, 7 ml/kg BW of an isotonic NaCl solution was administered i.v. Patients received either fentanyl 1.5 mg/kg BW i.v. before anaesthesia, or ketamine 0.7 mg/kg BW i.v. before anaesthesia, and 0.35 mg/kg BW 15 and 30 min after the first dose. No prophylactic vasopressor was used. During the first 40 min of anaesthesia a fluid load of 14 ml/kg BW was given i.v. If the mean arterial pressure (MAP) fell more than 20%, the infusion rate was increased. If the reduction in MAP exceeded 33% or if the systolic pressure decreased to less than 80 mmHg, patients were registered as haemodynamically unstable. In both groups the spinal anaesthesia caused a reduction in MAP. The MAP was lower in the fentanyl group than in the ketamine group at all times. In the fentanyl group six subjects developed a haemodynamically unstable condition, while only one subject in the ketamine group was registered as such (P less than 0.05). There was no significant change in heart rate in either group. We conclude that during spinal anaesthesia patients can in part be kept haemodynamically stable by intravenous administration of ketamine.     

Analgesia before a spinal block for femoral neck fracture: fascia iliaca compartment block

Background: In this prospective randomized study, the authors compared the analgesic effect of a fascia iliaca compartment (FIC) block with that of intravenous (i.v.) alfentanil when administered to facilitate positioning for spinal anaesthesia in elderly patients undergoing surgery for a femoral neck fracture.
Methods: The 40 patients were randomly assigned to one of two groups, namely, the FIC group (fascia iliaca compartment block, n =20) and the IVA group (intravenous analgesia with alfentanil, n =20). Group IVA patients received a bolus dose of i.v. alfentanil 10 μg/kg, followed by a continuous infusion of alfentanil 0.25 μg/kg/min starting 2 min before the spinal block, and group FIC patients received a FIC block with 30 ml of ropivacaine 3.75 mg/ml (112.5 mg) 20 min before the spinal block. Visual analogue pain scale (VAS) scores, time to achieve spinal anaesthesia, quality of patient positioning, and patient acceptance were compared.
Results: VAS scores during positioning (mean and range) were lower in the FIC group than in the IVA group [2.0 (1–4) vs. 3.5 (2–6), P =0.001], and the mean (± SD) time to achieve spinal anaesthesia was shorter in the FIC group (6.9 ± 2.7 min vs. 10.8 ± 5.6 min; P =0.009). Patient acceptance (yes/no) was also better in the FIC group (19/1) than in the IVA group (12/8)( P =0.008).
Conclusions: An FIC block is more efficacious than i.v. alfentanil in terms of facilitating the lateral position for spinal anaesthesia in elderly patients undergoing surgery for femoral neck fractures.     

Volume preloading is not essential to prevent spinal-induced hypotension at Caesarean section

We have compared the protective effect of 1000 ml preload with 200 ml preload of crystalloid solution, administered during the 10 min before spinal anaesthesia was induced, in 60 healthy women with no fetal compromise undergoing elective Caesarean section. The spinal anaesthetic was managed identically in both groups by an anaesthetist who was unaware of the volume of fluid administered. A prophylactic infusion of ephedrine 60 mg in Hartmann's solution 500 ml was given according to maternal arterial pressure. Hypotension was defined as > or = 30% reduction from baseline or < 90 mm Hg, and was treated by i.v. ephedrine bolus doses. There was no significant difference in ephedrine requirements between the two groups or in the incidence, severity or duration of hypotension: 10 women in the 1000-ml group, five episodes lasting > or = 3 min compared with nine women in the 200-ml group, four lasting > or = 3 min. There was no difference between neonates in each group. We have now abandoned the routine of preloading before regional anaesthesia.      

Effect of hypercapnia on arterial hypotension after induction of anaesthesia

We evaluated the effectiveness of intentional hypercapnia against hypotension after induction of anaesthesia with thiopental and isoflurane (TI) or propofol (P). For each group, 24 patients were anaesthetized with thiopental 4 mg kg(-1) (TI) or propofol 2 mg kg(-1) (P) for tracheal intubation and then lightly anaesthetized with isoflurane at 0.6% end-expiratory concentration (TI) or by 6 mg kg(-1) h(-1) infusion of propofol (P). In both anaesthesia groups, patients were randomly assigned to either normocapnia (end-tidal CO(2) = 35 mmHg) or hypercapnia (end-tidal CO(2) = 45 mmHg), which were achieved through adjusting the tidal volume. Systolic arterial pressure (SAP) 15 min after intubation was compared with the preanaesthetic baseline value. Under normocapnia, both TI and P induced a comparable, statistically significant suppression of SAP by approximately 20 mmHg from baseline. Hypercapnia prevented the decrease in SAP in TI but not in P. No patient in the TI-hypercapnia group experienced SAP below 100 mmHg, unlike those in the other groups. In conclusion, mild hypercapnia was effective in the prevention of hypotension in patients receiving thiopental followed by 0.6% end-expiratory isoflurane, but not in patients receiving 6 mg kg(-1) h(-1) propofol.     

A comparison between epidural anaesthesia using alkalinized solution and spinal (combined spinal/epidural) anaesthesia for elective caesarean section

In a double-blind investigation, 40 women undergoing elective lower segment caesarean section were randomly divided into two groups. Group I (n = 20) received spinal anaesthesia with 2.0 ml hyperbaric 0.5% bupivacaine using a single space combined spinal epidural technique. Group II (n = 20) received epidural anaesthesia with a local anaesthetic mixture consisting of 0.5% bupivacaine plain 10 ml and 2% lignocaine plain 10 ml to which was added 0.1 ml of adrenaline 1 in 1000 and 2 ml of 8.4% sodium bicarbonate. The mean onset times of sensory block to T4 and grade 3 motor blockade were 7.9 min and 9.5 min respectively in the spinal group, compared to 13.1 min and 16.3 min in the epidural group. These differences were both significant (P < 0.05). There was no difference between the two groups in the quality of analgesia or the incidence of hypotension and nausea. The relatively rapid onset of the pH adjusted epidural solution may provide an attractive alternative to spinal anaesthesia. Moreover, this study underlines the important role of pH adjusted epidural solutions in parturients progressing to emergency caesarean section with epidural catheters previously inserted for labour analgesia.     

The effect of oral etilefrine premedication on the incidence of hypotension during spinal anaesthesia

This study was designed to determine the efficacy of oral etilefrine in preventing hypotension induced by spinal anaesthesia. Forty patients, ASA grade I or II, aged 23-60 years, scheduled for orthopaedic surgery involving the lower extremity under spinal anaesthesia were studied. The patients were randomly allocated to one of two groups; the etilefrine group (n = 20) received oral etilefrine 15 mg (30 drops), 60 min before the subarachnoid block, and the control group (n = 20) received no etilefrine. Patients were given 0.5% isobaric bupivacaine intrathecally. Hypotension was defined as a 30% decrease from base-line for systolic arterial pressure and mean arterial pressure or systolic value <90 mmHg, and was treated with intravenous boluses of etilefrine 2 mg. The overall incidence of spinal anaesthesia induced hypotension was 25%, ranging from 20% in the etilefrine group to 30% in the control group. The fall in systolic arterial pressure and mean arterial pressure was significantly greater in the control group than in the etilefrine group (P < 0.05). The patients in the etilefrine group received less etilefrine supplement than those in control group and no subject in the etilefrine group required repeat etilefrine doses, while in the control group five patients received multiple etilefrine doses (P < 0.05). The mean heart rate remained fairly stable throughout the study periods. We conclude that oral etilefrine, given 60 min before surgery, reduces the fall in blood pressure during spinal anaesthesia.     

A prospective randomised trial comparing spinal anaesthesia using hyperbaric cinchocaine with general anaesthesia for lower limb vascular surgery

One hundred and one patients were randomly allocated to have their peripheral vascular surgery performed under general anaesthesia (51 patients) or spinal anaesthesia (50 patients). Intraoperative haemodynamic changes were markedly different between the two groups with a higher incidence of hypotension in the spinal group (72% vs 31%) and a higher incidence of hypertension in the general anaesthesia group (22% vs 0%). Blood loss was significantly less in the spinal group (560, SD 340, ml vs 792, SD 440, ml). Postoperatively three patients from the general anaesthesia group died from causes unrelated to the anaesthesia, and one had a myocardial infarct. Two patients in the spinal group had myocardial infarcts, both had been treated for bradycardia and hypotension intraoperatively, and one died. There was a significantly higher incidence of postoperative chest infection in the general anaesthesia group (33% vs 16%). There was no significant difference between the groups in the incidence of postoperative confusion, or lower limb amputation rate or need for further surgery prior to hospital discharge.     

Practice of spinal anesthesia in a developing country: usefulness of vascular preloading with a 7.5% hypertonic saline solution]

OBJECTIVE: To assess the efficacy of hypertonic saline for prevention of arterial hypotension in patients undergoing spinal anaesthesia in Niger. STUDY DESIGN: Prospective, randomized, double-blinded study. PATIENTS: Fifty adults undergoing scheduled surgery under spinal anaesthesia, allocated either to a hypertonic saline group (HSG) or a isotonic saline group (ISG). METHODS: Over the 15 min prior to anaesthesia, 100 mL of 7.5% saline were infused in patients of HSG, and 100 mL of 0.9% saline in those of ISG respectively. Spinal anaesthesia was performed at the L3-L4 or L4-L5 interspace using either lidocaine 5%, or bupivacaine 0.5% or a mixture of both supplemented with fentanyl. Arterial pressure (AP) and heart rate (HR) were measured the day before surgery, prior to and after spinal anaesthesia, thereafter every 5 min over 30 min and every 10 min thereafter until completion of surgery. Hypotension (30% decrease of systolic AP control value was treated with 500 mL of Ringer lactate solution and in case of failure with ephedrine (5-30 mg i.v.). An isolated bradycardia (HR < 60 b.min-1) was treated with atropine (0.5-1 mg i.v.). RESULTS: Hypotension occurred in two out of 24 patients of the HSG and eight out of 24 of the ISG (P < 0.05). The mean infused volumes of Ringer lactate solution were 387 +/- 218 mL vs 623 +/- 318 mL respectively (P < 0.05). Ephedrine and/or atropine were not required in HSG, however in 7 out of the 24 patients of the ISG. Adverse clinical effects did not occur. CONCLUSION: Hypertonic saline prevents efficiently the occurrence of hypotension during spinal anaesthesia. Considering its ease of preparation, the lack of adverse effects, in patients not suffering arterial hypertension or congestive heart failure, and low cost, hypertonic saline is well adapted for use in a developing country, if isotonic solutions are not available.     

A dose-response study of prophylactic intravenous ephedrine for the prevention of hypotension during spinal anesthesia for cesarean delivery

We performed a randomized, double-blinded dose-finding study of IV ephedrine for prophylaxis for hypotension in 80 women who received an IV crystalloid preload and spinal anesthesia for elective cesarean delivery. One minute after the intrathecal injection, patients were given saline control or ephedrine 10, 20, or 30 mg IV for 30 s. Systolic arterial pressure (SAP) in the first 12 min after the spinal injection was greater in the 30-mg group compared with other groups (P < 0.05). Hypotension occurred in 7 patients (35%) in the 30-mg group compared with 19 (95%), 17 (85%), and 16 (80%) patients in the control and 10- and 20-mg groups, respectively (P < 0.0001). Maximum decrease in SAP was smaller in the 30-mg group (mean lowest SAP 87% of baseline, range 58%-105%) compared with other groups (P < 0.01). Reactive hypertension occurred in 9 patients (45%) in the 30-mg group (mean highest SAP 120% of baseline, range 104%-143%) compared with 2 (10%), 1 (5%), and 5 (25%) patients in the other groups (P = 0.009). Heart rate changes, total ephedrine requirement, incidence of nausea and vomiting, and neonatal outcome were similar among groups. The proportion of patients with umbilical arterial pH < 7.2 was 10.5%, 25%, 42%, and 22% in the control, 10-, 20-, and 30-mg groups, respectively (P = 0. 12). We conclude that the smallest effective dose of ephedrine to reduce the incidence of hypotension was 30 mg. However, this dose did not completely eliminate hypotension, nausea and vomiting, and fetal acidosis, and it caused reactive hypertension in some patients. Implications: We investigated different doses of IV ephedrine as prophylaxis for hypotension during spinal anesthesia for cesarean delivery and found that the smallest effective dose was 30 mg. However, this dose did not completely eliminate hypotension, caused reactive hypertension in some patients, and did not improve neonatal outcome.