Prevention of spinal anesthesia-induced hypotension in the elderly: comparison between preanesthetic administration of crystalloids, colloids, and no prehydration

The influence of the infusion of ephedrine and phenylephrine on the hemodynamic stability after subarachnoid anesthesia in senior adults - a controlled randomized trial

Background

We studied the influence of ephedrine or phenylephrine infusion administered immediately after spinal anesthesia (SA) on hemodynamics in elderly orthopedic patients.

Methods

A prospective, randomized, double-blind, placebo-controlled study.

After a subarachnoid injection of 15 mg of levobupivacaine, the participants received an infusion of either ephedrine 20 mg (E group), phenylephrine 250 mcg (P group) or saline (C group) within 30 min. We measured blood pressure, cardiac index (CI) and heart rate (HR) from 15 min before to 30 min after SA.

Results

Seventy patients were included in the final analysis. At the end of measurements, mean arterial pressure (MAP) decreased significantly after SA in comparison to the baseline value in the C group but was maintained in the P and E group, with no significant differences between the groups. CI decreased after SA in the C group, was maintained in the P group, and increased significantly in the E group with significant differences between the C and E group (p = 0.049) also between the P and E (p = 0.01) group at the end of measurements. HR decreased significantly after SA in the C and P group but was maintained in the E group, with significant differences between the P and E group (p = 0.033) at the end of measurements.

Conclusions

Hemodynamic changes after SA in elderly orthopedic patients can be prevented by an immediate infusion of phenylephrine or ephedrine. In addition to maintaining blood pressure, the ephedrine infusion also maintains HR and increases CI after SA.

Trial registration

ISRCTN registry with registration number ISRCTN44377602, retrospectively registered on 15 June 2017.

Hypobaric Unilateral Spinal Anaesthesia versus General Anaesthesia in Elderly Patients Undergoing Hip Fracture Surgical Repair: A Prospective Randomised Open Trial

Objective

Intraoperative hypotension during hip fracture surgery is frequent in the elderly. No study has compared the haemodynamic effect of hypobaric unilateral spinal anaesthesia (HUSA) and standardised general anaesthesia (GA) in elderly patients undergoing hip fracture surgical repair.

Methods

We performed a prospective, randomised open study, including 40 patients aged over 75 years, comparing the haemodynamic effects of HUSA (5 mg isobaric bupivacaine with 5 μg sufentanil and 1 mL sterile water) and GA (induction with etomidate/remifentanil and maintenance with desflurane/remifentanil). An incidence of severe hypotension, defined by a decrease in systolic blood pressure of >40% from baseline, was the primary endpoint.

Results

The incidence of severe hypotension was lower in the HUSA group compared with that in the GA group (32% vs. 71%, respectively, p=0.03). The median [IQR] ephedrine consumption was lower (p=0.001) in the HUSA group (6 mg, 0-17 mg) compared with that in the GA group (36 mg, 21-57 mg). Intraoperative muscle relaxation and patients' and surgeons' satisfaction were similar between groups. No difference was observed in 5-day complications or 30-day mortality.

Conclusion

This study shows that HUSA provides better haemodynamic stability than GA, with lower consumption of ephedrine and similar operating conditions. This new approach of spinal anaesthesia seems to be safe and effective in elderly patients undergoing hip fracture surgery.

Effect of hydroxyethyl starch on blood glucose levels

Background

Hydroxyethyl starch (HES), a commonly used resuscitation fluid, has the property to induce hyperglycemia as it contains large ethyl starch, which can be metabolized to produce glucose. We evaluated the effect of 6% HES-130 on the blood glucose levels in non-diabetic patients undergoing surgery under spinal anesthesia.

Methods

Patients scheduled to undergo elective lower limb surgery were enrolled. Fifty-eight patients were divided into two groups according to the type of the main intravascular fluid used before spinal anesthesia (Group LR: lactated Ringer's solution, n = 30 vs. Group HES: 6% hydroxyethyl starch 130/0.4, n = 28). Blood glucose levels were measured at the following time points: 0 (baseline), 20 min (T1), 1 h (T2), 2 h (T3), 4 h (T4), and 6 h (T6).

Results

Mean blood glucose levels at T5 in the LR group and T4, T5 in the HES group, increased significantly compared to baseline. There were no significant changes in the serial differences of mean blood glucose levels from baseline between the two groups.

Conclusions

Administration of 6% HES-130 increased blood glucose levels within the physiologic limits, but the degree of glucose increase was not greater than that caused by administration of lactated Ringer's solution. In conclusion, we did not find evidence that 6% HES-130 induces hyperglycemia in non-diabetic patients.

Co-loading or pre-loading for prevention of hypotension after spinal anaesthesia! a therapeutic dilemma

Neuraxial blockade such as spinal anaesthesia can cause severe hypotension due to pharmacological sympathectomy resulting in potential deleterious consequences for the patient. Prevention of this spinal anaesthesia induced hypotension is of utmost importance especially in pregnant population as the life of mother as well as fetus is at risk. Several techniques and methodologies have been adopted for the prevention of this neuraxial hypotension with varying degree of success. The administration of intravenous fluids to optimize the blood volume during sympathectomy has been the most popular and widely used as the first line of therapy among these techniques. The intravenous fluids can be used both before and during the administration of spinal anaesthesia, the techniques appropriately named as pre-loading and co-loading respectively. Numerous research studies and available literary evidence suggests that both of these techniques can be equally effective in prevention of hypotension. The use of colloids has been observed to be more effective for pre-loading due to their longer half-life in the intravascular compartment. However, it has also been suggested that no technique is efficient in preventing the hypotension alone and has to be coupled with judicious use of vasopressors.

Crystalloid and colloid preload for maintaining cardiac output in elderly patients undergoing total hip replacement under spinal anesthesia

The aim of the present study was to compare the effects of colloid and crystalloid preload on cardiac output (CO) and incidence of hypotension in elderly patients under spinal anesthesia (SA). A randomized, double-blinded study was conducted including 47 elderly patients undergoing scheduled total hip replacement (THR), who were randomized to three groups: the control group (C group, n = 15), crystalloid (RS group, n =16) and colloid group (HES group, n = 16). An intravenous preload of 8 mL/kg of either lactated Ringer's solution in the RS group or 6% hydroxyethyl starch in the HES group was infused within 20 min before SA induction, while no intravenous preload was given in the C group. There was a trend of decrease in CO and systolic blood pressure after SA with time in the C group. In the RS and HES groups, CO increased significantly after fluid preloading as compared with baseline (P < 0.01). Thereafter, CO remained higher than baseline until 30 min after SA in the HES group. The change of systolic blood pressure was similar to CO, but no significant difference from baseline was observed in each group. Hypotension occurred in 3 patients in the C group and one each in the RS and HES group, respectively (P = 0.362). Intravascular volume preload with colloid is more effective than crystalloid solution in maintaining CO, which may be improved the hemodynamic stability in elderly patients during SA.

Comparison Between the Effects of Ringer`s Lactate and Hydroxyethyl Starch on Hemodynamic Parameters After Spinal Anesthesia: A Randomized Clinical Trial

BACKGROUND

Hypotension during spinal anesthesia is common and can lead to severe injuries and even death. Administration of crystalloid fluids is advised to prevent occurrence of hypotension; however its effectiveness is still the matter of arguments.

OBJECTIVES

This study was designed to compare the effects of Ringer`s lactate and hydroxyethyl starch 6% on hemodynamic parameters after spinal anesthesia in patients undergoing orthopedic surgeries on lower limbs.

PATIENTS AND METHODS

This randomized clinical trial was performed in Rasoul Akram Hospital, Tehran, Iran. 60 patients undergoing elective femoral fracture surgeries with spinal anesthesia were included in this study. Fitted patients were randomly divided into two equal groups. After entrance to the operation room and before spinal anesthesia, patients' hemodynamic parameters including systolic blood pressure (SBP), cardiac output (CO), and cardiac index (CI) were evaluated using monitoring electro-velocimetry set. In both groups, spinal anesthesia was performed using needle no. 25 and 3 mL of marcaine 0.5% in the sterile situation. None of the treatment group was aware of investigated group during the study.

RESULTS

The baseline values of mentioned variables did not show a significant difference between two groups using t-test (P > 0.05). Also SBP, CI, and CO after intervention was not significantly different between two groups using t-test (P > 0.05).

CONCLUSIONS

The result of present study on patients undergoing femoral fracture surgeries who received Hetastarch or Ringer`s lactate solutions showed that Hetastarch was not significantly more effective in compensation of hypotension induced by spinal anesthesia.

Effect of 6% hydroxyethyl starch-450 and low molecular weight dextran on blood sugar levels during surgery under subarachnoid block: A prospective randomised study

Dextrans and hydroxyethyl starches produce significant levels of free glucose residues following metabolism. The following study was designed to compare 6% hydroxyethyl starch-450 with Dextran 40, both used as preloading fluids, for their potential to raise peri-operative blood glucose levels. After taking an informed consent, 180 non-diabetic adult patients, posted for elective surgery under spinal anaesthesia, were randomly divided into three groups, to receive Ringer’s Lactate 20 ml/kg (group 1), Dextran 40,10 ml/kg (group 2) and Hestar 6%-450, 10 ml/kg (group 3), over half an hour, prior to the subarachnoid block, as preloading fluid, and serial capillary blood glucose measurements were taken thereafter at regular intervals up to 240 minutes from the baseline reading. All the three preloading fluids, including Ringer’s Lactate used as control, were seen to significantly increase the capillary blood glucose levels intra-operatively (P < 0.05), but the rise with Dextran-40 was seen to be sustained and highly significant (P < 0.001). We thus conclude that, Dextran40 causes a sustained and significant rise in peri-operative blood glucose levels.

A comparative evaluation of intrathecal bupivacaine alone, sufentanil or butorphanol in combination with bupivacaine for endoscopic urological surgery

BACKGROUND

The objective of the present study was to compare the onset, degree and recovery time of sensory and motor block and hemodynamic effects of intrathecal bupivacaine alone and bupivacaine with sufentanil or butorphanol in endoscopic urological surgeries.

METHODS

In a randomized, double-blind study, 90 patients of either sex and age, belonging to ASA Grades I and II, scheduled for elective endoscopic urological surgeries under spinal anesthesia, were allocated into three groups of 30 each. Patients received either 2.5 ml of 0.5% hyperbaric buypivacaine 12.5 mg (Group A), 1.5 ml of 0.5% hyperbaric bupivacaine 7.5 mg with 10 μg sufentanil (Group B) or 1.5 ml of 0.5% hyperbaric bupivacaine 7.5 mg with 25 μg butorphanol (Group C). Vital parameters, level, duration and regression of sensory block and motor block and side-effects were recorded and compared.

STATISTICAL ANALYSIS

Analysis of variance (ANOVA), post hoc test and Chi-square test were used.

RESULTS

Intrathecal addition of sufentanil/butorphanol prolonged the duration of sensory block (DOSB) compared with bupivacaine alone (DOSB being 156.83±23.83 min, 170.87 ± 22.21 min and 171.17 ± 23.99 min in groups A, B and C, respectively) without altering the duration of motor blockade. Bromage score 3 was achieved in 100%, 90% and 54.4% patients in groups A, B and C, respectively. The time to first request for analgesia was 112 ± 46.3 min, 323 ± 65.0 min and 299 ± 73.9 min in groups A, B and C, respectively. Complications were reduced by the addition of butorphanol, which also has a lower tendency than sufentanil to produce pruritus (60%).

CONCLUSIONS

The analgesia was significantly prolonged in groups B and C; group C had a less-intense motor block. Complications were reduced by the addition of butorphanol, which also has a lower tendency than sufentanil to produce pruritus. Thus, this combination of butorphanol with low-dose bupivacaine is especially beneficial in the geriatric group of patients who have multiple co-morbid conditions.

Issues in the perioperative management of the elderly patient with cardiovascular disease

The elderly patient may show normal physiological changes of the cardiovascular and respiratory systems that accompany aging, as well as features of intrinsic cardiac disease. The latter include: a past history of myocardial infarction or ischaemic heart disease; history of congestive cardiac failure; angina; arterial hypertension (BP >140/90mm Hg); and conduction disorders. A key aspect to the safe and effective anaesthetic management of the elderly patient with cardiac disease is a careful preoperative assessment and optimisation of pre-existing drug therapies. All cardiac medications should be continued up to and including the morning of surgery with the exception of anticoagulation involving warfarin, and perhaps large doses of angiotensin converting enzyme inhibitors and angiotensin II receptor antagonists in patients with hypertension or heart failure. Anaesthetic techniques used in these patients should avoid episodes of excessive hypotension after induction of anaesthesia or large blood loss, or the combination of hypertension and tachycardia after noxious stimulation. The latter physiological disturbances are pivotal for the development of myocardial ischaemia. Both premedication (if used) and anaesthesia should avoid excessive sedation and respiratory depression. The choice of anaesthetic technique may vary between: a balanced technique involving an opiate and a volatile agent; an intravenous technique utilising infusions of propofol; or regional anaesthesia with or without additional sedation. There are no good data to suggest any one technique is better than the rest. The occurrence of ischaemia in the perioperative period may precede the postoperative development of significant cardiac morbidity and mortality (including myocardial infarction or unstable angina, congestive cardiac failure, cerebrovascular accidents, and severe arrhythmias). A number of strategies have been examined to reduce these adverse outcomes. The effect of acute beta-adrenoceptor blockade in treatment-naive patients is associated with reduction in the haemodynamic response to noxious stimuli and decreased ECG evidence of myocardial ischaemia, as well as a reduction in the number of cardiac adverse events. Other drugs (calcium channel antagonists, alpha(2)-agonists and adenosine modulators) have a less predictable influence on both myocardial ischaemia and hard cardiac outcomes. There is inadequate evidence at present to define the optimal time course for acute beta-blockade, or the groups of patients in whom preoperative beta-blockade should be initiated in the absence of contraindications. Nevertheless, addition of beta-blockers to the preoperative regimen should be considered in patients with evidence of or at risk for coronary disease undergoing major surgery. There is also evidence that long-term beta-adrenoceptor or calcium channel blockade or nitrate therapy for the high-risk cardiac patient offers little protection against silent myocardial ischaemia, nonfatal infarction, cardiac failure and cardiac death.