Anesth Pain Med. 2021 February; 11(1):e111483. doi: 10.5812/aapm.111483.

Published online 2021 February 27. Research Article

Comparative Study of Effect of Spinal Anesthesia in Sitting and Lateral

Positions on the Onset Time of Sensory Block and Hemodynamic
Condition in Cesarean Section: A Randomized Clinical Trial
1, *
Nahid Manouchehrian , Abbas Moradi 2 and Leyla Torkashvand 2
1
Department of Anesthesiology, Hamadan University of Medical Sciences, Hamadan, Iran
2
Medical Sciences Faculty, Hamadan University of Medical Sciences, Hamadan, Iran
*
Corresponding author: Department of Anesthesiology, Fatemi Medical Center, Hamadan University of Medical Sciences, Pasdaran St, Hamadan, Iran. Email:
manuchehriann@gmail.com

Received 2020 November 27; Revised 2021 January 29; Accepted 2021 January 31.

Abstract

Background: Spinal anesthesia is the method of choice for the cesarean section. Hypotension is a common complication of this
method.
Objectives: This study aimed to compare the effect of spinal anesthesia in the sitting and lateral positions on the onset time of
sensory block and hemodynamic condition in cesarean sections.
Methods: In this clinical trial, 106 elective cesarean section candidates under spinal anesthesia were selected and randomly divided
into two groups: spinal anesthesia in the sitting position (group S) and the lateral position (group L). The onset time of the sensory
block, quality of sensory and motor block, hemodynamic condition, frequency of hypotension, nausea, and vomiting, and the doses
of ephedrine and atropine were compared between both groups. Data were analyzed with SPSS version 16 software at a 95% confi-
dence level.
Results: There was no statistically significant difference between the two groups in terms of age. The frequency of hypotension in
L and S groups was 24.5% and 57.7%, respectively (P = 0.001), in minute 6 after spinal anesthesia and 5.7% and 36.5%, respectively (P
< 0.001), in minute 8 after spinal anesthesia. The mean time to reach the sensory level of T6 was 1.30 ± 0.43 min versus 4.54 ± 2.12
min (P < 0.001), motor block score in minute 5 was 2.98 ± 0.14 versus 2.82 (P = 0.044), and ephedrine dose was 11.5 mg and 16.92 mg
in the L and S groups, respectively (P = 0.010). The maximum sensory-motor block and satisfaction of women with spinal anesthesia
were significantly higher in the lateral position than in the sitting position (P < 0.05).
Conclusions: Cesarean sections under spinal anesthesia in the lateral position than in the sitting position lead to a more rapid
sensory and motor block, reduced ephedrine consumption, and enhanced satisfaction of women.

Keywords: Cesarean Section, Spinal Anesthesia, Hemodynamic Changes, Sitting Position, Lateral Position, Sensory Block

1. Background but keeping the sitting position is very difficult for some
patients (like those who received sedatives, emergency pa-
Spinal anesthesia is the most common method for a
tients, multiple pregnancies, umbilical cord prolapse, and
cesarean section at the current time (1-4). Hypotension
restless patients). In these cases, placing the patient in the
is the most common complication of spinal anesthesia
lateral position is more suitable. Therefore, it is important
that occurs with a 30-60% incidence (5-10). Hypotension
to know how the patient’s hemodynamic status changes af-
following spinal anesthesia is more common in pregnant
ter spinal anesthesia in the lateral position (16, 17).
women, which is related partly to the cephalad dissemina-
tion of topical analgesics in subarachnoid space and partly Sympathectomy caused by spinal anesthesia, along
to the pressure imposed on aortocaval by the uterus of the with intensifying the peripheral blood accumulation
pregnant woman (11-14). caused by gravity, leads to considerable hypotension in
Spinal anesthesia is done in the sitting and lateral posi- the sitting position (15, 18). Hypotension creates problems
tions, each of which has advantages and disadvantages (15, for the mother and fetus, including vomiting, nausea, and
16). Spinal anesthesia in pregnant women is easier in the dizziness in the mother and acidemia in the fetus (19-21).
sitting position due to the obesity and unclear landmarks According to the above explanation, in theory, spinal

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(http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly
cited.
 Manouchehrian N et al.

anesthesia in the lateral position may be associated with sitting and lateral positions (according to randomization),
less hypotension. Various studies have been conducted in and an anesthesiologist who was unaware of the random-
this regard with different results about the incidence of ization and classification of the groups collected informa-
hypotension and onset time of anesthesia in the sitting tion.
and lateral positions for the cesarean section (16, 17). In all patients, 10 ml/kg Ringer solution was injected by
a peripheral venous catheter no.18 after entering the op-
eration room, and systolic and diastolic blood pressures,
2. Objectives
mean arterial pressure, heart rate, and initial SpO2 of pa-
This randomized study was conducted to compare the tients were measured by a non-invasive monitoring sys-
effect of spinal anesthesia in the sitting and lateral posi- tem (Saadat, Novin S1800 model, Iran). Then, patients
tions on the onset time of sensory block and hemodynamic in groups S and L underwent spinal anesthesia with a 25
condition in the cesarean section. gauge Quincke needle (Mekon Medical Devices Co. Shang-
hai, China) at the L3-L4 space in the midline in the sitting
and left lateral positions. After Cerebrospinal Fluid (CSF)
3. Methods aspiration, 10 mg hyperbaric bupivacaine 0.5% (2 mL, As-
traZeneca, Austria) with 2.5 µg Sufentanil (Sufiject Aburai-
3.1. Study Population
han Co., Iran) was injected into the subarachnoid space,
This clinical trial was conducted after approval and immediately, the patient was placed in the supine po-
by the Ethics Committee of Hamadan University of sition. Then, systolic and diastolic blood pressures, Mean
Medical Sciences (IR.UMSHA.REC.1397.414 and IRCT Arterial Pressure (MAP), Heart Rate (HR), and SpO2 were
20120915010841N13) and obtaining written informed recorded in both groups every two minutes until 10 min-
consent of patients in Fatemieh Hospital, Hamadan. Data utes (minutes 2, 4, 6, 8, and 10), followed by every five min-
collection tools included a researcher-made question- utes until 30 minutes (minutes 15, 20, 25, and 30) and every
naire in agreement with the research goals and variables. 10 minutes until 60 minutes (minutes 40, 50, and 60), by a
A convenience sampling method was used to form a sam- nurse of anesthesia.
ple of 106 patients (53 patients in each group). Patients The sensory block was evaluated with a pinprick in
were selected from among cesarean section candidates each minute, and the time of beginning the sensory block
under spinal anesthesia who met the inclusion criteria. (time to reach T6 sensory level) was recorded in the ques-
The inclusion criteria were 18-45-years-old, ASA class 1 tionnaire. The quality of sensory-motor block in minutes
or 2, not suffering from diabetes, hypertension, cardiac 5 and 10 after spinal anesthesia, ephedrine and atropine
diseases, kidney diseases, eclampsia, pre-eclampsia, and doses, nausea and vomiting, and Apgar score of the new-
spinal anesthesia contraindications (increased ICP, shock, born (minutes 1 and 5) were evaluated and recorded in
coagulation problems, and anemia). The exclusion criteria the questionnaire. After the operation, the satisfaction of
were lack of consent to participate in the study, an emer- the patient was asked (in percent) and recorded. Hypoten-
gency cesarean, multiple pregnancies, and failed spinal sion was defined as systolic blood pressure lower than 90
anesthesia. mmHg, and 10 mg ephedrine was used to treat it. Bradycar-
dia was defined as a heart rate lower than 60 per minute
3.2. Study Design and treated with 0.5 mg atropine. The Bromage score was
The sample size was calculated with a 0.05 alpha, 0.8 used to evaluate the quality of the motor block, and the fol-
power, 34% P1, and 56% P2 (incidence of hypotension in lowing scale was used for the quality of sensory block: Pain-
spinal anesthesia in the sitting and lateral positions based less: excellent, Mild tolerable pain: good, Moderate pain
on ref. No. 28). Finally, a total of 106 women were in- requiring sedatives: acceptable, and Severe pain requiring
cluded in two groups, including 53 subjects in the sitting general anesthesia: poor. On the Bromage scale, 0 = the
position (group S) and 53 subjects in the lateral position patient could raise the legs, 1 = the patient could flex the
(group L). Patients were divided randomly into two groups. knees, 2 = the patient could move only toes, and 3 = the pa-
Randomization was carried out by block randomization tient could not move the legs.
using quadruple blocks. We choose a block at random, and The classification of patients based on their physical
the first four treatments were allocated according to the condition was done according to the guidelines of the
block. Then, a new block was chosen at random, and the American Society of Anesthesiologists (ASA) from class 1 to
next four treatments were allocated. We kept going until class 6. A pinprick was used to determine the sensory block
the required sample size was collected. To blind the study, by a needle. The satisfaction of patients was determined
an anesthesia resident performed spinal anesthesia in the based on 0 to 100 scores, as follows: < 80%: not satisfied,

2 Anesth Pain Med. 2021; 11(1):e111483.

 Manouchehrian N et al.

80-90%: satisfied, and > 90%: very satisfied. in terms of atropine dosage. There was also no significant
difference in patients under spinal anesthesia in the sitting
3.3. Statistical Analysis and lateral positions in terms of the frequency of nausea
and vomiting, the maximum height of sensory block, and
Data obtained from completed questionnaires were
the mean time of returning to the T10 sensory level.
entered into SPSS-16 software and analyzed. The qualitative
The mean Apgar score of the newborn in minutes one
data were described as ratios and percentages. An indepen-
and five in the sitting and lateral positions was similar, and
dent t-test was used to compare the mean of systolic and di-
there was no significant difference (8.90 ± 0.36 in minute
astolic blood pressures, MAP, HR, and SpO2 in both groups.
one compared to 9.88 ± 0.38 in minute 5). The satisfac-
Repeated-measures analysis of variance was used to com-
tion of women under spinal anesthesia in the lateral posi-
pare between different times of measurement. A P value of
tion was significantly higher than in the sitting position (P
less than 0.05 was considered statistically significant.
= 0.001). There was no significant difference between the
two groups in terms of sensory and motor block quality,
4. Results and both groups were the same.

In this research, 106 women, including 53 women in

group S (spinal anesthesia in the sitting position) and 53 5. Discussion
women in group L (spinal anesthesia in the left lateral posi-
tion) were studied. One woman was excluded from group This study aimed at comparing the effect of spinal
S due to failure in spinal anesthesia and repeated spinal anesthesia in the sitting and lateral positions on the onset
anesthesia. Thus, 105 patients in group S (n = 52) and group time of the sensory block and hemodynamic condition in
L (n = 53) were studied (Figure 1). C/S. In the current study, mean systolic and diastolic blood
The mean ages of women in spinal anesthesia in the sit- pressures, Mean Arterial Pressure (MAP), and SpO2 of pa-
ting and lateral positions were 31.00 ± 5.013 and 30.28 ± tients under spinal anesthesia in the sitting position in
6.86, respectively. There was no statistically significant dif- minutes 6 and 8 after anesthesia were significantly lower
ference between the groups in age. than those of patients in the lateral position. The onset
According to Table 1, mean systolic and diastolic blood time of the sensory block was lower in the lateral position
pressures and MAP in minutes 6 and 8 after spinal anesthe- than in the sitting position.
sia were significantly lower in patients in the sitting po- Satisfaction with spinal anesthesia in the lateral posi-
sition than in patients in the lateral position (P < 0.05). tion was significantly higher than that in the sitting po-
Based on Table 2, the mean SpO2 in minutes 6 and 8 after sition, but there was no statistically significant difference
spinal anesthesia was significantly lower in patients in the between the groups in terms of heart rate, quality of sen-
sitting position than in patients in the lateral position (P < sory and motor block, the maximum height of the sensory
0.05). Hence, the mean heart rate in both sitting and lat- block, mean atropine and ephedrine doses, frequency of
eral positions 60 minutes after spinal anesthesia showed nausea and vomiting, and mean Apgar score in minutes 1
no significant difference. In minutes 6 and 8 after spinal and 5.
anesthesia, the frequency of hypotension in patients un- The study by Muhammad et al. (22), which was per-
der the cesarean section with spinal anesthesia in the sit- formed on 130 pregnant women undergoing cesarean sec-
ting position was significantly higher than that in patients tions under spinal anesthesia using hyperbaric bupiva-
in the lateral position (P < 0.05). Regarding Table 3, in pa- caine in the sitting and lateral positions, showed that the
tients under spinal anesthesia in the lateral position, the occurrence of hypotension in the lateral position was sig-
mean onset time of sensory block (time to reach the sen- nificantly less frequent than that in the sitting position
sory level of T6) was significantly lower (P < 0.001), and the (30.7% vs. 52.3%). The findings of this study about the inci-
mean motor block score in minute 5 was higher (P = 0.04) dence of hypotension in minutes 6 and 8 after spinal anes-
when compared to patients in the sitting position. There thesia are consistent with the results of Muhammad et al.
was no statistically significant difference between the two study.
groups in the motor block score in minute 10. In Ortiz-Goez et al. study (23) of 252 pregnant women
According to Table 4, the mean ephedrine dose in pa- candidates for elective cesarean sections under spinal
tients under spinal anesthesia in the sitting position (11.59 anesthesia in three positions of sitting and lateral (right
± 10.99) was significantly higher than that in patients in and left sides), the incidence of hypotension was 50.7% in
the lateral position (16.92 ± 11.94) (P = 0.010). There was no the sitting position, 60% in the lateral position (left side),
statistically significant difference between the two groups and 69.2% in the lateral position (right side). There was

Anesth Pain Med. 2021; 11(1):e111483. 3

 Manouchehrian N et al.

Enrollment Assessed for eligibility (n = 130)

Excluded (n = 24)
• Not meeting inclusion criteria (n = 20)
• Declined to participate (n = 4)
• Other reasons (n = 0)

Randomized (n = 106)

Allocation

Allocated to intervention (n = 53) Allocated to intervention (n = 53)

• Received allocated intervention (n = 53) • Received allocated intervention (n = 53)
• Did not receive allocated intervention (n = 0) • Did not receive allocated intervention (n = 0)

Follow-Up
Lost to followup(n = 1) Lost to followup (n = 0)
Sitting Position Lateral Position

Analysis
Analysed (n = 52 ) Analysed (n = 53)
• Excluded from analysis (n = 0) • Excluded from analysis (n = 0)

Figure 1. Consort diagram

no difference between the three groups regarding the in- sensory block in the sitting position group in minutes 1
cidence of hypotension and the need to use vasopressin and 5 had a delay when compared to the lateral position
(ephedrine or phenylephrine). In the current study, the group, but there was no significant difference in the qual-
mean ephedrine dosage in women under spinal anesthesia ity and level of the sensory block between both groups.
in the sitting position was significantly higher than that in There was also no significant difference in hypotension in-
women in the lateral position. cidence and satisfaction between both groups. Consistent
with Chevuri et al. study (25), the onset time of the sensory
A randomized clinical trial conducted by Atashkhooei
block in the lateral position was lower than that in the sit-
et al. (24) about the effect of women’s positions during
ting position in our study, but the satisfaction of women
spinal anesthesia in the cesarean section on hemodynamic
in this group was also higher than that of women in the
condition showed that there was no statistically signifi-
sitting position.
cant difference between both groups, as the current study
and hypotension was significantly lower in the lateral po- In a study conducted by Inglis et al. (26) on 40 preg-
sition than in the sitting position. The study by Chevuri nant women candidates for cesarean sections under spinal
et al. (25) on 40 pregnant women candidates for elective anesthesia in the lateral and sitting positions, the sensory
cesarean sections under spinal anesthesia in the sitting block up to T6 developed faster in the lateral group than
and lateral positions indicated that the onset time of the in the sitting group. The maximum block height, mo-

4 Anesth Pain Med. 2021; 11(1):e111483.

 Manouchehrian N et al.

Table 1. Comparison of Systolic, Diastolic, and Mean Arterial Pressure in Sitting and Lateral Groups Based on Measurement Time

Measurement Time Systolic Blood Pressure (mmHg) Diastolic Blood Pressure (mmHg) MAP (mmHg)

S Group, Mean ± SD L Group, Mean ± SD P Value S Group, Mean ± SD L Group, Mean ± SD P Value S Group, Mean ± SD L Group, Mean ± SD P Value

Before spinal 121.87 ± 10.82 125.30 ± 11.79 0.123 75.51 ± 11.26 78.98 ± 09.98 0.096 89.83 ± 11.10 93.56 ± 08.90 0.059
anesthesia

After spinal anesthesia 119.65 ± 13.72 120.32 ± 14.08 0.806 71.77 ± 14.82 71.92 ± 14.53 0.957 87.08 ± 14.01 86.09 ± 14.48 0.726

Minute 2 105.44 ± 18.18 102.55 ± 18.39 0.419 61.60 ± 16.58 61.92 ± 16.36 0.919 74.73 ± 16.26 75.32 ± 15.77 0.851

Minute 4 96.44 ± 17.45 94.68 ± 17.50 0.919 56.46 ± 16.21 57.23 ± 13.56 0.794 68.48 ± 15.70 68.79 ± 13.93 0.915

Minute 6 93.83 ± 16.57 102.24 ± 17.04 0.012a 52.50 ± 11. 70 59.72 ± 14.46 0.006a 65.83 ± 15.40 72.00 ± 16.64 0.022a

Minute 8 100.58 ± 17.65 109.08 ± 14.20 0.008a 55.65 ± 15.07 61.94 ± 13. 72 0.027a 69.94 ± 15.40 76.72 ± 13.70 0.019a

Minute 10 108.79 ± 14.09 109.26 ± 12.08 0.853 60.21 ± 14.50 60.04 ± 10.79 0.945 75.00 ± 15.29 75.47 ± 10.69 0.855

Minute 15 109.35 ± 14.34 110.81 ± 13.06 0.585 59.36 ± 11.84 59.72 ± 12.31 0.882 75.77 ± 13.34 76.04 ± 12.52 0.915

Minute 20 109.09 ± 14.80 109.49 ± 11.97 0.881 57.67 ± 12.27 58.23 ± 09.22 0.794 73.44 ± 12.04 74.08 ± 09.29 0.763

Minute 25 107.69 ± 15.37 106.85 ± 08.50 0.728 56.31 ± 10.35 56.62 ± 09.07 0.869 72.94 ± 13.15 71.96 ± 08.73 0.653

Minute 30 109.46 ± 12.56 107.08 ± 09.69 0.278 56.63 ± 11. 18 56.23 ± 08.62 0.834 73. 73 ± 11.58 71. 92 ± 09.22 0.378

Minute 40 109.04 ± 11.05 108.54 ± 08.72 0.798 56.67 ± 09.55 57.19 ± 07.09 0.754 72.88 ± 09.49 72.90 ± 07.32 0.991

Minute 50 108.53 ± 09.44 108.37 ± 08.32 0.917 56.88 ± 08. 94 57.40 ± 06.89 0.741 71.47 ± 13.09 73.27 ± 06.99 0.384

Minute 60 108.76 ± 07.82 108.98 ± 08.15 0.888 57.16 ± 07.64 59.71 ± 07.09 0.085 73.33 ± 08.10 75.33 ± 06.57 0.131

a Significant.

Table 2. Comparison of SpO2 , Heart Rate, and Hypotension in Sitting and Lateral groups Based on Measurement Time

Measurement Time SpO2 (%) Heart Rate (Per Minute) Hypotension (Number of Patients)

S Group, Mean ± SD L Group, Mean ± SD P Value S Group, Mean ± SD L Group, Mean ± SD P Value S Group (n) L Group (n) P Value

Before spinal anesthesia 97.02 ± 1.27 97.64 ± 1.29 0.121 93.51 ± 16.42 94.63 ± 14.84 0.713
¯ ¯ ¯
After spinal anesthesia 97.43 ± 1.39 97.83 ± 1.28 0.131 95.54 ± 17.51 100.13 ± 16.17 0.165 1 (1.9) 0 (0) 0.495

Minute 2 97.67 ± 1.39 98.04 ± 1.34 0.17 94.40 ± 24.97 93.72 ± 20.08 0.877 11 (21.2) 17 (32.1) 0.206

Minute 4 97.78 ± 1.38 98.19 ± 1.32 0.129 9.261 ± 22.38 94.98 ± 22.58 0.591 26 (50) 25 (47.2) 0.772

Minute 6 97.69 ± 1.59 98.32 ± 1.25 0.026a 92.04 ± 24.32 95.60 ± 19.84 0.412 30 (57.7) 13 (24.5) 0.001a

Minute 8 97.63 ± 1.52 98.36 ± 1.16 0.007a 95.83 ± 22.70 98.02 ± 18.60 0.589 19 (36.5) 3 (5.7) 0.001a

Minute 10 97.67 ± 1.53 98.23 ± 1.44 0.059 98.90 ± 17.15 97.47 ± 19.69 0.692 4 (7.7) 2 (3.8) 0.387

Minute 15 97.83 ± 1.41 98.23 ± 1.34 0.137 100.27 ± 20.16 98.47 ± 17.56 0.627 3 (5.8) 0 (0) 0.118

Minute 20 97.79 ± 1.36 98.23 ± 1.37 0.103 99.52 ± 19.84 99.11 ± 15.89 0.908 5 (9.6) 0 (0) 0.027a

Minute 25 97.79 ± 1.44 98.24 ± 1.33 0.093 101.23 ± 16.57 98.34 ± 14.62 0.345 4 (7.7) 1 (1.9) 0.205

Minute 30 97.85 ± 1.42 98.23 ± 1.39 0.169 100.09 ± 17.76 98.79 ± 13.70 0.674 3 (5.8) 1 (1.9) 0.363

Minute 40 97.90 ± 1.33 98.17 ± 1.44 0.324 100.36 ± 14.05 97.81 ± 14.53 0.364 1 (1.9) 0 (0) 1

Minute 50 97.90 ± 1.33 98.23 ± 1.32 0.211 99.04 ± 13.23 96.09 ± 11.68 0.234 0 (0) 0 (0) 0.211

Minute 60 98.04 ± 1.17 98.19 ± 1.34 98.19 ± 1.34 96.14 ± 11.07 93.85 ± 11.85 0.317 0 (0) 0 (0) 0.559

a Significant.

Table 3. Comparison of Onset of Sensory Block and Motor Block Score in Minutes 5 and 10 in Sitting and Lateral groups

Variable Sitting Lateral P Value

Onset of sensory block 4.54 ± 2.12 1.30 ± 0.43 < 0.001

Motor block in minute 5 2.82 ± 0.52 2.98 ± 0.14 0.044

Motor block in minute 10 2.90 ± 0.36 3.00 ± 0.00 0.058

tor block, and hemodynamic condition in both groups nant women candidates for elective cesarean sections un-
showed no difference. Consistent with the Inglis et al. der spinal anesthesia in the sitting and lateral positions.
study, the sensory block up to T6 formed faster in the lat- Consistent with Obasuyi et al, study (28), hypotension oc-
eral position than in the sitting position in our study. Con- curred less frequently in the lateral than the sitting posi-
trary to our study, in a study conducted by Xu et al. (27), tion but the onset of hypotension was similar between the
there was no significant difference in hypotension inci- two groups.
dence and mean arterial pressure reduction between preg- In Shahzad et al. study (16) of 70 patients older than 60

Anesth Pain Med. 2021; 11(1):e111483. 5

 Manouchehrian N et al.

Table 4. Comparison of Ephedrine and Atropine Doses in Sitting and Lateral Groups

Variable Sitting Lateral P Value

Ephedrine 16.92 ± 11.94 11.51 ± 10.99 0.010

Atropine 0.134 ± 0.10 0.153 ± 0.15 0. 467

years (male and female) who were candidates for lower ab- reduced ephedrine consumption, and enhanced satisfac-
domen and pelvis surgery under spinal anesthesia in the tion of women when compared to spinal anesthesia in the
sitting and lateral (right) positions, the two groups were sitting position.
similar in the heart rate, systolic and diastolic blood pres-
sures 20 minutes after spinal anesthesia, but contrary to
Acknowledgments
our study, the onset time of anesthesia was faster in the sit-
ting position group. Patients felt more comfortable in the
This research was derived from a thesis that was sup-
lateral position and were more satisfied.
ported by the Hamadan University of Medical Sciences,
Hallworth et al. (29), in a study of the effect of baric-
Hamadan, Iran.
ity and position of the patient on the dissemination of
bupivacaine on 150 pregnant women candidates for elec-
tive cesarean sections under spinal anesthesia in the sit- Footnotes
ting and lateral positions showed that in the lateral posi-
tion, Trendelenburg positioning did not affect the sensory Authors’ Contribution: 1. Study concept and design:
block when compared to the sitting position. In our study, Nahid Manouchehrian. 2. Analysis and interpretation of
the mean onset time of the sensory block in the lateral po- data: Abbas Moradi and Nahid Manouchehrian. 3. Draft-
sition was significantly lower and satisfaction was signifi- ing of the manuscript: Nahid Manouchehrian. 4. Critical
cantly higher than those in the sitting position. revision of the manuscript for important intellectual con-
Manouchehrian et al. (30) studied the effect of hemo- tent: Nahid Manouchehrian. 5. Statistical analysis: Abbas
dynamic changes from the lateral position (left side) to Moradi. 6. Administrative, technical, and material sup-
the sitting position before spinal anesthesia on hypoten- port: Nahid Manouchehrian and Leyla Torkashvand.
sion incidence during surgery in 63 patients who were Clinical Trial Registration Code:
candidates for cesarean sections under spinal anesthesia. IRCT20120915010841N13.
This study showed that systolic blood pressure in the lat- Conflict of Interests: We declare that there is no conflict
eral position was lower than that in the sitting position. of interest in this paper.
The increased range of changes in systolic blood pres- Ethical Approval: This study was approved by the Ethics
sure from the lateral to sitting position before performing Committee of Hamadan University of Medical Sciences
spinal anesthesia showed higher hypotension during the (permit no. IR.UMSHA.REC. 1397.414), in adherence to the
cesarean section that could act as a predictor for hypoten- Declaration of Helsinki guidelines.
sion after spinal anesthesia. In this study, contrary to our
Funding/Support: The study received no financial sup-
study, systolic blood pressure in the lateral position before
port.
spinal anesthesia was lower than that in the sitting posi-
tion. Informed Consent: All subjects signed informed consent
forms regarding the use of their samples and basic infor-
The strengths of the present study included the suffi-
mation when they were hospitalized.
cient sample size, evaluation made by the researcher (eval-
uation was not dependent on patient’s response), and ac-
curate monitoring of the patient’s hemodynamics. The References
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