comparison of crystalloid preloading versus crystalloid coloading to prevent hypotension and...

7/30/2019 Comparison of Crystalloid Preloading Versus Crystalloid Coloading to Prevent Hypotension and Bradycardia Followi

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The administration of large volumes of

intravenous crystalloids, 15-20 minutes before spinal

anaesthesia, to prevent hypotension is a common

practice.1 Recently a more rational approach to applyfluid loading at the time that the local anaesthesia

block is starting to take effect has been advocated.2

This might maximize intravascular volume expansion

during vasodilatation from the sympathetic blockade

and limit fluid redistribution and excretion. We designed

this study to test the hypothesis that rapid administration

of crystalloid at the time of induction of spinal

anaesthesia (Coload) is associated with less hypotension

and bradycardia than the administration of an equivalent

volume of preload.

Comparison of Crystalloid Preloading Versus Crystalloid Coloadingto Prevent Hypotension and Bradycardia following Spinal Anaesthesia

Manu Bose, Gurudas Kini, Krishna H. M.

ABSTRACT

Background: We compared the effect of preloading against coloading with 15 mlkg -1 of Lactated Ringer solutionin preventing hypotension and bradycardia following subarachnoid block.

Patients & Methods: Fifty four adult ASA physical status 1 and 2 patients scheduled for elective knee and anklearthroscopies were randomized into 2 groups after informed consent. Group P received Ringers lactate 20minutes before spinal anaesthesia. Group C received equal volume over 20 minutes after spinal block. Baselineheart rate, systolic, diastolic and mean arterial pressures were recorded. The same parameters were thenrecorded at 2, 4, 6, 8, 10 minutes after spinal anaesthesia and thereafter every 5 minutes for 45 minutes.Decrease in heart rate >20%, mean arterial pressure >30% from baseline was considered significant clinicallyand number of such episodes recorded. Dosage of mephentermine and atropine used to treat hypotension andbradycardia was recorded in both the groups. Incidence of giddiness and nausea were recorded. Quantitativedata were compared with Students t test and qualitative data with Chi square or Fisher exact test. P


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PATIENTS & METHODS

This prospective randomized study was conducted

after obtaining approval from institutional review board.

Fifty four patients were enrolled into the study after

obtaining their written informed consent. ASA physical

status 1 or 2 patients, aged between 18-60 years, weighing

50-90 kgs scheduled to undergo elective knee or ankle

arthroscopies were included in the study. Patients with

height


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hypotension was comparable between the two groups

(Table 4). Cumulative dose of 7.8 mg atropine was

used to treat bradycardia in both the groups. Total dose

of mephentermine used in group P was 15 mg and in

group C 9 mg. In group P, 3 patients had giddiness and

2 patients had nausea. In group C none had giddiness

or nausea. Incidence of nausea and giddiness werecomparable between the two groups (P=0.239 and 0.491

for giddiness and nausea respectively).

DISCUSSION

We found that coloading was only as effective as

preloading the patient with crystalloids to prevent spinal

induced hypotension and bradycardia.

Though preloading is a common practice to

prevent spinal induced hypotension, the efficacy of

crystalloid before spinal block has been tested mostlyin obstetric patients and its benefits have been small.3-

6 Only few studies have evaluated the value of

crystalloid administration before spinal block versus no

crystalloids in general surgical population.7-10 They

found no significant difference in the incidence of

spinal induced hypotension between patients receiving

and not receiving crystalloids before spinal anaesthesia.

Since studies did not consistently prove the efficacy

of preloading, interest was focused on coloading. A

sustained rise in cardiac output was demonstrated in

a group of patients who received Ringers lactate after

initiation of spinal anaesthesia.11 Kinetic analysis ofintravenous infusion of Ringers lactate as preload

suggested that rapid fluid administration over two

minutes after induction of spinal or general anaesthesia

for non obstetric surgery might prevent hypotension

caused by central hypovolaemia.12

Our observations contradict the findings of an

earlier study which found that significantly more patients

in the coloading group did not require vasopressor

Table 2

Trend of heart rate. Data are mean

(standard deviation)

Time (minutes) Group P - Group C -heart rate heart rate

(beats per min.) (beats per min.)

Baseline 74 (15) 77 (16)

2 76 (17) 78 (15)

4 75 (18) 74 (16)

6 74 (18) 70 (13)

8 71 (18) 69 (12)

10 68 (18) 68 (11)

15 67 (18) 66 (10)

20 64 (14) 66 (9)25 64 (12) 65 (9)

30 63 (10) 65 (9)

35 63 (9) 65 (9)

40 63 (11) 66 (9)

45 64 (10) 67 (9)

Table 3

Trend of mean arterial pressure. Data are mean

(standard deviation)

Time (minutes) Group P Group C(mm Hg) (mm Hg)

Baseline 96 (15) 96 (12)

2 88 (15) 90 (11)

4 82 (19) 85 (10)

6 81 (15) 82 (11)

8 83 (14) 83 (10)

10 82 (13) 83 (9)

15 83 (14) 84 (8)

20 82 (12) 82 (9)

25 83 (14) 84 (9)30 84 (13) 82 (13)

35 85 (13) 83 (9)

40 84 (12) 84 (10)

45 84 (13) 85 (8)

Table 4

Comparison of episodes of clinically significant

decrease in heart rate and mean arterial pressure

Group P Group C(number of (number of

episodes) episodes)

Significant decrease 13 13

in heart rate

Significant decrease in 5 3

mean arterial pressure

J Anaesth Clin Pharmacol 2008; 24(1): 53-56


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therapy.13 They found that the coloading group required

a lower median dose and a lower median number of

ephedrine doses for treatment of maternal hypotension.

However, their study was conducted on pregnants

undergoing elective caesarian section. This differencecould probably be attributable to the difference in

physiology between the pregnant population and general

surgical population. In our study, we found that the

dosage of vasopressor and atropine administered to the

patients during first 45 minutes was comparable.

Our study confirms the findings of Baustita, Mojica

et al, but we did not include a placebo or control group

(with neither preloading nor coloading) in our study for

ethical reasons.14 We have compared coloading with

preloading, the utility of which itself has been questioned.

This is one of the lacunae in our study. Due to absence

of control group in our study, the efficacy of preloading

in preventing spinal induced hypotension cannot be

commented upon.

In busy operating room schedules with rapid

turnover of cases coloading would be a more efficient

method to prevent spinal induced hypotension than

preloading. However caution needs to be exercised to

extrapolate this to pregnants or ASA physical status 3

and 4 patients.

We conclude that coloading with 15 mlkg-1 oflactated Ringer solution is as effective as preloading

with same volume over 20 minutes before subarachnoid

block to prevent hypotension and bradycardia.

REFERENCES

1. Covino BG, Scott DB, Lambert DH. Handbook ofspinal anesthesia and analgesia. Philadelphia: WBSaunders, 1994

2. Pouta AM, Karinen J, Vuolteenaho OJ, LaatikainenTJ. Effect of intravenous fluid preload on vasoactivepeptide secretion during caeserian section underspinal anaesthesia. Anaesthesia 1996; 51: 128-32

3. Rout CC, Rocke DS, Levin J et al. A revaluation ofthe role of crystalloid administration for theprevention of hypotension associated with spinalanesthesia for elective caeserian section.Anesthesiology 1993; 79: 262-9

4. Rout CC, Akoojee SS, Rocke DA, Gouws E. Rapid

administration of crystalloid preload does not

decrease the incidence of hypotension after spinal

anesthesia for elective caeserian section. Br J Anaesth

1992; 68: 394-75. Rocke DA, Rout CC. Volume preloading, spinal

hypotension and caeserian section. Br J Anaesth

1995; 75: 257-9

6. Jackson P, Reid JA, Thorburn J. Volume preloading

is not essential to prevent spinal-induced hypotension

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7. Venn PJ, Simpson DA, Rubin AP, Edstrom HH.

Effect of fluid preloading on cardiovascular variables

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bupivacaine. Br J Anaesth 1989; 63: 682-7

8. Coe AJ, Revanas B. Is crystalloid preloading useful

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9. Buggy D, Higgins P, Moran C, et al.Prevention of

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Analg 1997; 84: 106-10

10. Casati A, Fanelli G, Berti M, et al. Cardiac

performance during unilateral lumbar spinal block

after crystalloid preload. Can J Anaesth 1997;

44:623-8

11. Kamenik M, Paver-Erzen V. The effect of lactated

Ringers solution infusion on cardiac output changes

after spinal anesthesia. Anesth Analg 2001; 92: 710-

14

12. Ewaldsson CA, Hahn RG. Volume kinetics of Ringers

solution during induction of spinal and general

anaesthesia. Br J Anaesth 2001; 87:406-14

13. Dyer RA, Farina Z. Crystalloid preload versus rapid

crystalloid administration after induction of spinal

anesthesia (coload) for elective caesarean section.Obstetric Anesthesia Digest 2005; 25: 44-45

14. Mojica JL, Melendez HJ, Bautista LE. The timing

of intravenous crystalloid administration and

incidence of cardiovascular side effects during

spinal anesthesia: the results from a randomized

controlled trial. Anesth Analg 2002; 94:432-37

BOSE M; ET AL: COMPARISON OF CRYSTALLOID PRELOADING VERSUS CRYSTALLOID COLOADING

comparison of crystalloid preloading versus crystalloid coloading to prevent hypotension and...

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