Reversal of hyperdynamic response to continuous endotoxin administration by inhibition of NO synthesis

1992 ◽  
Vol 73 (1) ◽  
pp. 324-328 ◽  
Author(s):  
J. Meyer ◽  
L. D. Traber ◽  
S. Nelson ◽  
C. W. Lentz ◽  
H. Nakazawa ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Methyl Ester ◽  
Arterial Pressure ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Resistance Index ◽  
Volume Index ◽  
Systemic Vascular Resistance Index ◽  
Cardiovascular Performance

Septic shock is characterized by an increase in cardiac output and a fall in systemic vascular resistance index and mean arterial pressure. Endotoxin alters the smooth muscle function of blood vessels, probably by means of an increased production of the potent vasodilator nitric oxide (NO). The present study was accomplished to determine how the inhibition of NO synthesis influences cardiovascular performance in an ovine model of hyperdynamic endotoxemia. Endotoxemia was induced in five range ewes (41 +/- 2 kg) by continuous infusion of Escherichia coli endotoxin (LPS, 10 ng.kg-1.min-1) over the entire study period. After 24 h of LPS infusion, cardiac output increased from 5.2 +/- 0.3 to 7.9 +/- 0.6 (SE) 1/min (P less than 0.05) and mean arterial pressure and systemic vascular resistance index fell from 92 +/- 5 to 79 +/- 6 mmHg (P = 0.08) and from 1,473 +/- 173 to 824 +/- 108 dyn.s.cm-5.m2 (P less than 0.05), respectively. The pulmonary shunt fraction increased from 0.23 +/- 0.03 to 0.32 +/- 0.03 (P less than 0.05). The intravenous administration of the NO synthase inhibitor N omega-nitro-L-arginine methyl ester (25 mg/kg) 24 h after the start of the LPS infusion changed these values to approximately baseline levels over the subsequent 4 h. Although N omega-nitro-L-arginine methyl ester increased pulmonary arterial pressure and pulmonary vascular resistance (P less than 0.05), right and left ventricular stroke volume index showed no significant changes. It is concluded that NO has a major function in cardiovascular performance in endotoxemia.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Mechanisms contributing to hypotension after anesthetic induction with sufentanil, propofol, and rocuronium: a prospective observational study

2021 ◽  
Author(s):  
Bernd Saugel ◽  
Elisa-Johanna Bebert ◽  
Luisa Briesenick ◽  
Phillip Hoppe ◽  
Gillis Greiwe ◽  
...  
Keyword(s):  
Heart Rate ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Resistance Index ◽  
Stroke Volume Index ◽  
Volume Index ◽  
Systemic Vascular Resistance Index ◽  
Anesthetic Induction

AbstractIt remains unclear whether reduced myocardial contractility, venous dilation with decreased venous return, or arterial dilation with reduced systemic vascular resistance contribute most to hypotension after induction of general anesthesia. We sought to assess the relative contribution of various hemodynamic mechanisms to hypotension after induction of general anesthesia with sufentanil, propofol, and rocuronium. In this prospective observational study, we continuously recorded hemodynamic variables during anesthetic induction using a finger-cuff method in 92 non-cardiac surgery patients. After sufentanil administration, there was no clinically important change in arterial pressure, but heart rate increased from baseline by 11 (99.89% confidence interval: 7 to 16) bpm (P < 0.001). After administration of propofol, mean arterial pressure decreased by 23 (17 to 28) mmHg and systemic vascular resistance index decreased by 565 (419 to 712) dyn*s*cm−5*m2 (P values < 0.001). Mean arterial pressure was < 65 mmHg in 27 patients (29%). After propofol administration, heart rate returned to baseline, and stroke volume index and cardiac index remained stable. After tracheal intubation, there were no clinically important differences compared to baseline in heart rate, stroke volume index, and cardiac index, but arterial pressure and systemic vascular resistance index remained markedly decreased. Anesthetic induction with sufentanil, propofol, and rocuronium reduced arterial pressure and systemic vascular resistance index. Heart rate, stroke volume index, and cardiac index remained stable. Post-induction hypotension therefore appears to result from arterial dilation with reduced systemic vascular resistance rather than venous dilation or reduced myocardial contractility.

scholarly journals Hemodynamic Changes Associated with Spinal Anesthesia for Cesarean Delivery in Severe Preeclampsia

2008 ◽  
Vol 108 (5) ◽  
pp. 802-811 ◽  
Author(s):  
Robert A. Dyer ◽  
Jenna L. Piercy ◽  
Anthony R. Reed ◽  
Carl J. Lombard ◽  
Leann K. Schoeman ◽  
...  
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Spinal Anesthesia ◽  
Cesarean Delivery ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Severe Preeclampsia

Background Hemodynamic responses to spinal anesthesia (SA) for cesarean delivery in patients with severe preeclampsia are poorly understood. This study used a beat-by-beat monitor of cardiac output (CO) to characterize the response to SA. The hypothesis was that CO would decrease from baseline values by less than 20%. Methods Fifteen patients with severe preeclampsia consented to an observational study. The monitor employed used pulse wave form analysis to estimate nominal stroke volume. Calibration was by lithium dilution. CO and systemic vascular resistance were derived from the measured stroke volume, heart rate, and mean arterial pressure. In addition, the hemodynamic effects of phenylephrine, the response to delivery and oxytocin, and hemodynamics during recovery from SA were recorded. Hemodynamic values were averaged for defined time intervals before, during, and after SA. Results Cardiac output remained stable from induction of SA until the time of request for analgesia. Mean arterial pressure and systemic vascular resistance decreased significantly from the time of adoption of the supine position until the end of surgery. After oxytocin administration, systemic vascular resistance decreased and heart rate and CO increased. Phenylephrine, 50 mug, increased mean arterial pressure to above target values and did not significantly change CO. At the time of recovery from SA, there were no clinically relevant changes from baseline hemodynamic values. Conclusions Spinal anesthesia in severe preeclampsia was associated with clinically insignificant changes in CO. Phenylephrine restored mean arterial pressure but did not increase maternal CO. Oxytocin caused transient marked hypotension, tachycardia, and increases in CO.

scholarly journals Effects of Different Doses of Magnesium Sulfate on Pneumoperitoneum-related Hemodynamic Changes in Patients Undergoing Gastrointestinal Laparoscopy: a randomized, double-blind, controlled trial

2019 ◽  
Author(s):  
Wei Tan ◽  
Dong-chen Qian ◽  
Meng-meng Zheng ◽  
Xuan Lu ◽  
Yuan Han ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Central Venous Pressure ◽  
Magnesium Sulfate ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Venous Pressure ◽  
Control Group ◽  
Central Venous

Abstract Background: The infusion of magnesium sulfate is well known to reduce arterial pressure and attenuate hemodynamic response to pneumoperitoneum. This study aimed to investigate whether different doses of magnesium sulfate can effectively attenuate the pneumoperitoneum-related hemodynamic changes and the release of vasopressin in patients undergoing laparoscopic gastrointestinal surgery. Methods: Sixty-nine patients undergoing laparoscopic partial gastrectomy were randomized into three groups: group L received magnesium sulfate 30 mg/kg loading dose and 15 mg/kg/h continuous maintenance infusion for 1 h; group H received magnesium sulfate 50 mg/kg followed by 30 mg/kg/h for 1 h; and group S (control group) received same volume 0.9% saline infusion, immediately before the induction of pneumoperitoneum. Systemic vascular resistance (SVR), cardiac output (CO), mean arterial pressure (MAP), heart rate (HR), central venous pressure(CVP), serum vasopressin and magnesium concentrations were measured. The extubation time, visual analogue scale were also assessed. The primary outcome is the difference in SVR between different groups. The secondary outcome is the differences of other indicators between groups, such as CO, MAP, HR, CVP, vasopressin and postoperative pain score. Results: Pneumoperitoneum instantly resulted in a significant reduction of cardiac output and an increase in mean arterial pressure, systemic vascular resistance, central venous pressure and heart rate in the control group (P < 0.01). The mean arterial pressure (T2 – T4), systemic vascular resistance (T2 – T3), central venous pressure(T3-T5) and the level of serum vasopressin were significantly lower (P < 0.05) and the cardiac output (T2 – T3) was significantly higher (P < 0.05) in group H than those in the control group. The mean arterial pressure (T4), systemic vascular resistance (T2), and central venous pressure(T3-T4) were significantly lower in group H than those in group L (P < 0.05). Furthermore, the visual analog scales at 5 min and 20 min, the level of vasopressin, and the dose of remifentanil were significantly decreased in group H compared to the control group and group L (P < 0.01). Conclusion: Magnesium sulfate could safely and effectively attenuate the pneumoperitoneum-related hemodynamic instability during gastrointestinal laparoscopy and improve postoperative pain at serum magnesium concentrations above 2 mmol/L.

scholarly journals Effects of Different Doses of Magnesium Sulfate on Pneumoperitoneum-related Hemodynamic Changes in Patients Undergoing Gastrointestinal Laparoscopy

2019 ◽  
Author(s):  
Wei Tan ◽  
Dong-chen Qian ◽  
Meng-meng Zheng ◽  
Xuan Lu ◽  
Yuan Han ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Central Venous Pressure ◽  
Magnesium Sulfate ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Venous Pressure ◽  
Control Group ◽  
Central Venous

Abstract Background: The infusion of magnesium sulfate is well known to reduce arterial pressure and attenuate hemodynamic response to pneumoperitoneum. This study aimed to investigate whether different doses of magnesium sulfate can effectively attenuate the pneumoperitoneum-related hemodynamic changes and the release of vasopressin in patients undergoing laparoscopic gastrointestinal surgery. Methods: Sixty-nine patients undergoing laparoscopic partial gastrectomy were randomized into three groups: group L received magnesium sulfate 30 mg/kg loading dose and 15 mg/kg/h continuous maintenance infusion for 1 h; group H received magnesium sulfate 50 mg/kg followed by 30 mg/kg/h for 1 h; and group S (control group) received same volume 0.9% saline infusion, immediately before the induction of pneumoperitoneum. Systemic vascular resistance (SVR), cardiac output (CO), mean arterial pressure (MAP), heart rate (HR), central venous pressure(CVP), serum vasopressin and magnesium concentrations were measured. The extubation time, visual analogue scale were also assessed. The primary outcome is the difference in SVR between different groups. The secondary outcome is the differences of other indicators between groups, such as CO, MAP, HR, CVP, vasopressin and postoperative pain score. Results: Pneumoperitoneum instantly resulted in a significant reduction of cardiac output and an increase in mean arterial pressure, systemic vascular resistance, central venous pressure and heart rate in the control group (P < 0.01). The mean arterial pressure (T2 – T4), systemic vascular resistance (T2 – T3), central venous pressure(T3-T5) and the level of serum vasopressin were significantly lower (P < 0.05) and the cardiac output (T2 – T3) was significantly higher (P < 0.05) in group H than those in the control group. The mean arterial pressure (T4), systemic vascular resistance (T2), and central venous pressure(T3-T4) were significantly lower in group H than those in group L (P < 0.05). Furthermore, the visual analog scales at 5 min and 20 min, the level of vasopressin, and the dose of remifentanil were significantly decreased in group H compared to the control group and group L (P < 0.01). Conclusion: Magnesium sulfate could safely and effectively attenuate the pneumoperitoneum-related hemodynamic instability during gastrointestinal laparoscopy and improve postoperative pain at serum magnesium concentrations above 2 mmol/L.

Circulatory responses to onset of exercise: role of arterial and cardiac baroreflexes

1985 ◽  
Vol 248 (4) ◽  
pp. H457-H467 ◽  
Author(s):  
J. Ludbrook ◽  
W. F. Graham
Keyword(s):  
Arterial Pressure ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Resistance Index ◽  
Systemic Vascular Resistance Index ◽  
Receptor Input ◽  
Cardiovascular Variables ◽  
Tonic Reflex ◽  
Cardiac Receptors

Six rabbits were exercised on a moving belt at 13 m/min for 60's. Heart rate (HR), mean arterial pressure (MAP), cardiac index (CI), and systemic vascular resistance index (SVRI) were measured. Exercise was done under the following four permutations of input from baroreceptors (B) and cardiac receptors (C): BC, both inputs present; B, only baroreceptor input (intrapericardial procaine); C, only cardiac receptor input (surgical barodenervation); 0, both inputs deleted. The reflex effects on SVRI of the two inputs were calculated as (B - 0) and (C - 0) and their interaction as (BC - 0) - [(B - 0) + (C - 0)]. The effects of baroreceptor input plus interaction on all cardiovascular variables were also calculated, as (BC - C). At rest, (B - 0) and (C - 0) each tonically depressed SVRI without interacting, and (BC - C) tonically depressed SVRI, MAP, and HR. Within 10 s of the start of exercise these tonic effects were abolished, although a small, SVRI-lowering interaction appeared. Suppression of the tonic reflex effects of arterial baroreceptor and cardiac receptor input supported systemic vascular resistance at the onset of exercise and contributed to the rise of arterial pressure.

scholarly journals Effects of Different Doses of Magnesium Sulfate on Pneumoperitoneum-related Hemodynamic Changes in Patients Undergoing Gastrointestinal Laparoscopy

2019 ◽  
Author(s):  
Wei Tan ◽  
Dong-chen Qian ◽  
Meng-meng Zheng ◽  
Xuan Lu ◽  
Yuan Han ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Magnesium Sulfate ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Control Group ◽  
Hemodynamic Changes ◽  
The Mean ◽  
Different Doses

Abstract Background The infusion of magnesium sulfate is well known to reduce arterial pressure and attenuate hemodynamic response to pneumoperitoneum. This study aimed to investigate whether different doses of magnesium sulfate can effectively attenuate the pneumoperitoneum-related hemodynamic changes and the release of vasopressin in patients undergoing laparoscopic gastrointestinal surgery. Methods Sixty-nine patients undergoing laparoscopic partial gastrectomy were randomized into three groups: group L received magnesium sulfate 30 mg/kg loading dose and 15 mg/kg/h continuous maintenance infusion for 1 h; group H received magnesium sulfate 50 mg/kg followed by 30 mg/kg/h for 1 h; and group S (control group) received same volume 0.9% saline infusion, immediately before the induction of pneumoperitoneum. Systemic vascular resistance (SVR), cardiac output (CO), mean arterial pressure (MAP), heart rate (HR), serum vasopressin and magnesium concentrations were measured. The extubation time, visual analogue scale were also assessed. The primary outcome is the difference in SVR between different groups. The secondary outcome is the differences of other indicators between groups, such as CO, MAP, HR, vasopressin and postoperative pain score. Results Pneumoperitoneum instantly resulted in a significant reduction of cardiac output and an increase in mean arterial pressure, systemic vascular resistance, and heart rate in the control group (P < 0.01). The mean arterial pressure (T2 – T4), systemic vascular resistance (T2 – T3) and the level of serum vasopressin were significantly lower (P < 0.05) and the cardiac output (T2 – T3) was significantly higher (P < 0.05) in group H than those in the control group. The mean arterial pressure (T4) and systemic vascular resistance (T2) were significantly lower in group H than those in group L (P < 0.05). Furthermore, the visual analogue scales at 5 min and 20 min, the level of vasopressin, and the dosage of remifentanil were significantly decreased in group H compared to the control group and group L (P < 0.01). Conclusion Magnesium sulfate could safely and effectively attenuate the pneumoperitoneum-related hemodynamic instability during gastrointestinal laparoscopy and improve postoperative pain at serum magnesium concentrations above 2 mmol/L.

scholarly journals Effects of different doses of magnesium sulfate on pneumoperitoneum-related hemodynamic changes in patients undergoing gastrointestinal laparoscopy: a randomized, double-blind, controlled trial

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Wei Tan ◽  
Dong-chen Qian ◽  
Meng-meng Zheng ◽  
Xuan Lu ◽  
Yuan Han ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Central Venous Pressure ◽  
Magnesium Sulfate ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Venous Pressure ◽  
Control Group ◽  
Central Venous

Abstract Background The infusion of magnesium sulfate is well known to reduce arterial pressure and attenuate hemodynamic response to pneumoperitoneum. This study aimed to investigate whether different doses of magnesium sulfate can effectively attenuate the pneumoperitoneum-related hemodynamic changes and the release of vasopressin in patients undergoing laparoscopic gastrointestinal surgery. Methods Sixty-nine patients undergoing laparoscopic partial gastrectomy were randomized into three groups: group L received magnesium sulfate 30 mg/kg loading dose and 15 mg/kg/h continuous maintenance infusion for 1 h; group H received magnesium sulfate 50 mg/kg followed by 30 mg/kg/h for 1 h; and group S (control group) received same volume 0.9% saline infusion, immediately before the induction of pneumoperitoneum. Systemic vascular resistance (SVR), cardiac output (CO), mean arterial pressure (MAP), heart rate (HR), central venous pressure (CVP), serum vasopressin and magnesium concentrations were measured. The extubation time, visual analogue scale were also assessed. The primary outcome is the difference in SVR between different groups. The secondary outcome is the differences of other indicators between groups, such as CO, MAP, HR, CVP, vasopressin and postoperative pain score. Results Pneumoperitoneum instantly resulted in a significant reduction of cardiac output and an increase in mean arterial pressure, systemic vascular resistance, central venous pressure and heart rate in the control group (P <  0.01). The mean arterial pressure (T2 – T4), systemic vascular resistance (T2 – T3), central venous pressure(T3-T5) and the level of serum vasopressin were significantly lower (P <  0.05) and the cardiac output (T2 – T3) was significantly higher (P <  0.05) in group H than those in the control group. The mean arterial pressure (T4), systemic vascular resistance (T2), and central venous pressure(T3-T4) were significantly lower in group H than those in group L (P <  0.05). Furthermore, the visual analog scales at 5 min and 20 min, the level of vasopressin, and the dose of remifentanil were significantly decreased in group H compared to the control group and group L (P <  0.01). Conclusion Magnesium sulfate could safely and effectively attenuate the pneumoperitoneum-related hemodynamic instability during gastrointestinal laparoscopy and improve postoperative pain at serum magnesium concentrations above 2 mmol/L. Trial registration The study was retrospectively registered at Chinese Clinical Trial Registry; the registration number is ChiCTR-IPD-17011145, principal investigator: D.Y. Q., date of registration: April 13, 2017.

Abstract 11340: Increasing Mean Arterial Pressure or Cardiac Output in Comatose Out-of-Hospital Cardiac Arrest Patients Undergoing Targeted Temperature Management: Effects on Cerebral Tissue Oxygenation

Circulation ◽  
2021 ◽  
Vol 144 (Suppl_2) ◽  
Author(s):  
Johannes Grand ◽  
Sebastian Wiberg ◽  
Jesper Kjaergaard ◽  
Christian Hassager
Keyword(s):  
Cardiac Output ◽  
Intensive Care ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Oxygen Saturation ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Cerebral Oxygen Saturation ◽  
Cerebral Oxygen ◽  
Cardiac Intensive Care

Introduction: There are few data regarding the effects of norepinephrine-uptitration on global and regional hemodynamics in cardiac intensive care patients. Methods: We prospectively studied 10 OHCA patients at our cardiac intensive care unit. The trial consisted of 5 phases. The first 4 phases were achieved by titrating norepinephrine to reach targets of mean arterial pressure (MAP). First a MAP of 65 mmHg, second 75 mmHg, third 85 mmHg, fourth 65 mmHg again. The fifth phase was with a constant MAP of 65 mmHg but aiming at an increased PaCO2 from 6.5-7.3 kPa to increase cardiac output. During each phase, 20 minutes steady state was achieved before measurements. We measured hemodynamic variables with a Swan-Ganz catheter, arterial and mixed venous blood gases, and near-infrared spectroscopy at the forehead (cerebral oxygen saturation). Results: To obtain a MAP at 85 mmHg, norepinephrine was increased from 0.11±0.02 to 0.18±0.02 μg · kg–1 · min–1 (P < 0.001). Norepinephrine uptitration significantly increased MAP, systemic vascular resistance and pulmonary artery pressure, without affecting cardiac output or heart rate. After phase 3, norepinephrine was decreased to basal values, and all variables returned to baseline. Increasing pCO2, resulted in a significant increase in cardiac output and cerebral oxygen saturation, while decreasing systemic vascular resistance. MAP (and NE dose) was unaffected by increasing pCO2. Conclusions: A short-term increase in MAP with norepinephrine in resuscitated OHCA-patients is associated with increased SVR and PVR without affecting cardiac output or NIRS of the brain. An increase in CO caused by an increase in pCO2 and thereby a decreased SVR increased NIRS potentially improving brain oxygenation.

scholarly journals Effects of Different Doses of Magnesium Sulfate on Pneumoperitoneum-related Hemodynamic Changes in Patients Undergoing Gastrointestinal Laparoscopy

2019 ◽  
Author(s):  
Wei Tan ◽  
Dong-chen Qian ◽  
Meng-meng Zheng ◽  
Xuan Lu ◽  
Yuan Han ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Central Venous Pressure ◽  
Magnesium Sulfate ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Venous Pressure ◽  
Control Group ◽  
Central Venous

Abstract Background: The infusion of magnesium sulfate is well known to reduce arterial pressure and attenuate hemodynamic response to pneumoperitoneum. This study aimed to investigate whether different doses of magnesium sulfate can effectively attenuate the pneumoperitoneum-related hemodynamic changes and the release of vasopressin in patients undergoing laparoscopic gastrointestinal surgery. Methods: Sixty-nine patients undergoing laparoscopic partial gastrectomy were randomized into three groups: group L received magnesium sulfate 30 mg/kg loading dose and 15 mg/kg/h continuous maintenance infusion for 1 h; group H received magnesium sulfate 50 mg/kg followed by 30 mg/kg/h for 1 h; and group S (control group) received same volume 0.9% saline infusion, immediately before the induction of pneumoperitoneum. Systemic vascular resistance (SVR), cardiac output (CO), mean arterial pressure (MAP), heart rate (HR), central venous pressure(CVP), serum vasopressin and magnesium concentrations were measured. The extubation time, visual analogue scale were also assessed. The primary outcome is the difference in SVR between different groups. The secondary outcome is the differences of other indicators between groups, such as CO, MAP, HR, CVP, vasopressin and postoperative pain score. Results: Pneumoperitoneum instantly resulted in a significant reduction of cardiac output and an increase in mean arterial pressure, systemic vascular resistance, central venous pressure and heart rate in the control group (P < 0.01). The mean arterial pressure (T2 – T4), systemic vascular resistance (T2 – T3), central venous pressure(T3-T5) and the level of serum vasopressin were significantly lower (P < 0.05) and the cardiac output (T2 – T3) was significantly higher (P < 0.05) in group H than those in the control group. The mean arterial pressure (T4) , systemic vascular resistance (T2) and central venous pressure(T3-T4) were significantly lower in group H than those in group L (P < 0.05). Furthermore, the visual analogue scales at 5 min and 20 min, the level of vasopressin, and the dosage of remifentanil were significantly decreased in group H compared to the control group and group L (P < 0.01). Conclusion: Magnesium sulfate could safely and effectively attenuate the pneumoperitoneum-related hemodynamic instability during gastrointestinal laparoscopy and improve postoperative pain at serum magnesium concentrations above 2 mmol/L.

scholarly journals Effects of vagotomy on cardiovascular response to periodic apneas in sedated pigs

1999 ◽  
Vol 86 (6) ◽  
pp. 1890-1896 ◽  
Author(s):  
D. Slamowitz ◽  
L. Chen ◽  
S. M. Scharf
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Stroke Volume ◽  
Systemic Vascular Resistance ◽  
Vascular Resistance ◽  
Cardiovascular Response ◽  
Pressor Response ◽  
Mechanical Effects

There are few studies investigating the influence of vagally mediated reflexes on the cardiovascular response to apneas. In 12 sedated preinstrumented pigs, we studied the effects of vagotomy during apneas, controlling for apnea periodicity and thoracic mechanical effects. Nonobstructive apneas were produced by paralyzing and mechanically ventilating the animals, then turning the ventilator off and on every 30 s. Before vagotomy, relative to baseline, apnea caused increased mean arterial pressure (MAP; +19 ± 25%, P < 0.05), systemic vascular resistance (SVR; +33 ± 16%, P < 0.0005), and heart rate (HR; +5 ± 6%, P < 0.05) and decreased cardiac output (CO) and stroke volume (SV; −16 ± 10% P < 0.001). After vagotomy, no significant change occurred in MAP, SVR, and SV during apneas, but CO and HR increased relative to baseline. HR was always greater (∼14%, P < 0.01) during the interapneic interval compared with during apnea. We conclude that vagally mediated reflexes are important mediators of the apneic pressor response. HR increases after apnea termination are related, at least in part, to nonvagally mediated reflexes.

Sign in / Sign up

Export Citation Format

Share Document