Sanaa Helmy - Academia.edu (original) (raw)

Papers by Sanaa Helmy

Research paper thumbnail of The Effect of the Preemptive Use of the NMDA Receptor Antagonist Dextromethorphan on Postoperative Analgesic Requirements

Anesthesia and Analgesia, 2001

Both central sensitization after peripheral tissue injury and the development of opiate tolerance... more Both central sensitization after peripheral tissue injury and the development of opiate tolerance involve activation of N-methyl-D-aspartate receptors. In this double-blinded, randomized study, we investigated the preemptive versus postincisional effects of dextromethorphan, an N-methyl-D-aspartate receptor antagonist, on postoperative pain management. Sixty ASA I and II patients undergoing elective upper abdominal surgery were randomly allocated to three equally sized groups. The Preincisional group patients received dextromethorphan (120 mg) IM 30 min before skin incision and a placebo (isotonic saline) 30 min before the end of surgery. The Postincisional group received the same dose of dextromethorphan 30 min before the end of surgery and a placebo 30 min before skin incision, and the Control group received a placebo both 30 min before skin incision and 30 min before the end of surgery. A standard general anesthetic technique including fentanyl, propofol, isoflurane, and atracurium was used. Postoperative meperidine patient-controlled analgesia (PCA) was used. There were no significant group differences in the median pain scores except in the visual analog scale at 6 h both at rest and on movement; these were significantly lower in the Preincisional group than the other two groups (P < 0.05). The mean time to initiation of PCA was significantly longer in the Preincisional than in the Postincisional and Control groups (mean [SD]: 10.7 [2.2 h], 5.4 [2.1 h], and 3.7 [1.6 h], respectively; P < 0.001]. The 24-h PCA-meperidine consumption was significantly less in the Preincisional than in the Postincisional and Control groups (mean [SD]: 140 [60 mg], 390 [80 mg], and 570 [70 mg], respectively; P < 0.001]. The incidence of postoperative hypoxemia (SpO(2) < 90%) and nausea was significantly less in the Preincisional group (P < 0.05). In conclusion, preincisional IM 120 mg dextromethorphan compared with the same postincisional dose significantly reduced postoperative meperidine consumption. IM administration of preincisional dextromethorphan (120 mg), allowing the use of a larger dose sufficient to block the central sensitization caused by activation of the N-methyl-D-aspartate receptors, provides preemptive analgesia and has a supportive role in postoperative pain relief, as shown by a significant decrease in 24-h meperidine consumption.

Research paper thumbnail of Prophylactic anti-emetic efficacy of ondansetron in laparoscopic cholecystectomy under total intravenous anaesthesiaA randomised, double-blind comparison with droperidol, metoclopramide and placebo

Anaesthesia, 1999

The prophylactic anti-emetic efficacy and safety of pre-operative intravenous ondansetron was eva... more The prophylactic anti-emetic efficacy and safety of pre-operative intravenous ondansetron was evaluated in a randomised, double-blind, comparison with droperidol, metoclopramide and placebo in 160 ASA grade 1 and 2 patients undergoing laparoscopic cholecystectomy under total intravenous anaesthesia. The patients were randomly allocated to receive ondansetron (4 mg), droperidol (1.25 mg), metoclopramide (10 mg) or placebo given as a single intravenous dose immediately before induction of a standardised general anaesthetic. There were no significant differences between the four study groups with regard to the demographic and anaesthetic data, postoperative analgesia, postoperative sedation scores, duration of postoperative hospital stay and incidence of adverse events. The incidence of nausea and vomiting was significantly lower (p`0.05) between 1 h and 4 h after surgery in the ondansetron group compared with the droperidol, metoclopramide and placebo groups. The incidence of nausea was similar in the four groups in the other study periods: 0-1 h and 4-24 h. The incidence of vomiting was lower in the ondansetron, droperidol and metoclopramide groups than in the placebo group between 1 and 4 h but was the same between 4 and 24 h. As a result of the lower incidence of nausea and vomiting between 1 h and 4 h in the ondansetron group, the overall incidence of nausea and vomiting was lower during the first 24 h after surgery in this group than in the other three groups.

Research paper thumbnail of The immunomodulatory effects of prolonged intravenous infusion of propofol versus midazolam in critically ill surgical patients

Anaesthesia, 2001

Both propofol and midazolam are known to inhibit immune function. The aim of this study was to in... more Both propofol and midazolam are known to inhibit immune function. The aim of this study was to investigate cytokine production in critically ill surgical patients as early markers of immune response to prolonged infusion of propofol and midazolam. The study enrolled 40 elective patients who were to receive long-term sedation for more than 2 days. Patients were randomly allocated to one of two equally sized groups. Central venous blood samples for measurement of interleukin-1b (IL-1b), interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-8 (IL-8), tumour necrosis factor-a (TNF-a) and interferon-g (IFN-g) were drawn prior to the start and after 48 h of infusion. After 48 h, propofol caused significant increases in IL-1b (24%), IL-6 (23%) and TNF-a (4.8 times) levels, while midazolam caused significant decreases in IL-1b (21%), IL-6 (21%) and TNF-a (19%). Both agents caused significant decreases in IL-8 levels (propofol: 30%, midazolam: 48%, p , 0.05). Propofol caused significant decreases in IL-2 levels (68%, p , 0.001) but increases in IFN-g (30%, p , 0.05), whereas there was no significant change with midazolam compared with the pre-infusion level. In conclusion, during 48 h of continuous infusion, propofol stimulated, while midazolam suppressed, the production of the pro-inflammatory cytokines IL-1b, IL-6 and TNF-a, and both caused suppression of IL-8 production. Propofol inhibited IL-2 production and stimulated IFN-g production, whereas midazolam failed to do so. Therefore, sedative agents may have clinical implications in high-risk and immunocompromised patients.

Research paper thumbnail of The effect of halothane and isoflurane on plasma cytokine levels

Anaesthesia, 2000

The aim of this study was to investigate the effect of halothane vs. isoflurane on cytokine produ... more The aim of this study was to investigate the effect of halothane vs. isoflurane on cytokine production during minor elective surgery. Forty adult patients, ASA I-II were randomly allocated to receive halothane or isoflurane. Venous samples for interleukin (IL)-1beta, IL-2, IL-6, tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) were taken before anaesthesia, before incision, at the end of anaesthesia and 24 h postoperatively. In both groups, IL-6 and TNF-alpha levels remained low throughout the study period. Before incision, in both groups IL-1beta and IFN-gamma showed a decrease (p<0.01 for IL-1beta in isoflurane group and p<0.05 for the others) compared with pre-induction. By the end of anaesthesia and surgery, IL-1beta had increased significantly (p<0.05) and IFN-gamma had decreased significantly (p<0.05) in both groups compared with pre-incisional levels. By 24 h postoperatively in both groups, IL-1beta had decreased significantly (p<0.05), whereas IFN-gamma had increased significantly (p<0.05) compared with the end of anaesthesia and surgery level. Pre-incisionally, IL-2 increased in the halothane group (p<0.01), whereas it decreased significantly in the isoflurane group (p<0.001) compared with the pre-induction level. By the end of anaesthesia and surgery and by 24 h postoperatively, IL-2 had decreased significantly in the halothane group (p<0.001), whereas it increased significantly in the isoflurane group (p<0.001) compared with pre-incision and end of anaesthesia and surgery levels, respectively.

Research paper thumbnail of The effect of anaesthesia and surgery on plasma cytokine production

Anaesthesia, 1999

The aim of this study was to investigate cytokine production in response to anaesthesia [total in... more The aim of this study was to investigate cytokine production in response to anaesthesia [total intravenous anaesthesia (TIVA) with propofol, sufentanil and atracurium] and surgery (laparoscopic vs. open cholecystectomy). Forty adult patients, ASA I-II, undergoing elective laparoscopic (group 1) or open (group 2) cholecystectomy were studied. Venous blood samples for measurement of interleukin (IL)-1b, IL-2, IL-4, IL-6, tumour necrosis factor-a (TNF-a) and interferon-g (IFN-g) were taken before the induction of anaesthesia, pre-incisionaly, at the end of anaesthesia and surgery and 24-h postoperatively. Pre-incisionaly, in both groups, IL-1b, IL-4, IL-6, TNF-a and IFN-g did not show a significant change, whereas IL-2 showed a significant decrease (p < 0.005 in group 1 and p < 0.001 in group 2) compared with pre-induction levels. By the end of anaesthesia and surgery, IL-1b, IL-2, IL-4, IL-6 and TNF-a showed a significant increase in group 2 (p < 0.005 for IL-1b, IL-2 and IL-4, and p < 0.05 for IL-6 and TNF-a); while in group 1, only IL-2 showed a significant increase (p < 0.01) and IFN-g showed a significant decrease (p < 0.05) compared with pre-incisional levels. By 24-h postoperatively, IL-1b, IL-4, IL-6 and TNF-a had decreased significantly in group 2 (p < 0.005 for IL-4 and p < 0.05 for the others); whereas in group 1, IL-2 and IFN-g showed a significant increase (p < 0.005) compared with the end of anaesthesia and surgery level. In conclusion, TIVA with propofol, sufentanil and atracurium does not seem to have a significant effect on IL-1b, IL-4, IL-6, TNF-a and IFN-g release. IL-2 was the only cytokine to show a significant decrease due to the effect of anaesthesia alone in both groups. The cytokine response to open cholecystectomy stimulated both the pro-inflammatory (IL-1b, IL-6 and TNF-a) and the anti-inflammatory (IL-4) components, while this response was absent in laparoscopic cholecystectomy.

Research paper thumbnail of The Effect of the Preemptive Use of the NMDA Receptor Antagonist Dextromethorphan on Postoperative Analgesic Requirements

Anesthesia and Analgesia, 2001

Both central sensitization after peripheral tissue injury and the development of opiate tolerance... more Both central sensitization after peripheral tissue injury and the development of opiate tolerance involve activation of N-methyl-D-aspartate receptors. In this double-blinded, randomized study, we investigated the preemptive versus postincisional effects of dextromethorphan, an N-methyl-D-aspartate receptor antagonist, on postoperative pain management. Sixty ASA I and II patients undergoing elective upper abdominal surgery were randomly allocated to three equally sized groups. The Preincisional group patients received dextromethorphan (120 mg) IM 30 min before skin incision and a placebo (isotonic saline) 30 min before the end of surgery. The Postincisional group received the same dose of dextromethorphan 30 min before the end of surgery and a placebo 30 min before skin incision, and the Control group received a placebo both 30 min before skin incision and 30 min before the end of surgery. A standard general anesthetic technique including fentanyl, propofol, isoflurane, and atracurium was used. Postoperative meperidine patient-controlled analgesia (PCA) was used. There were no significant group differences in the median pain scores except in the visual analog scale at 6 h both at rest and on movement; these were significantly lower in the Preincisional group than the other two groups (P &amp;amp;lt; 0.05). The mean time to initiation of PCA was significantly longer in the Preincisional than in the Postincisional and Control groups (mean [SD]: 10.7 [2.2 h], 5.4 [2.1 h], and 3.7 [1.6 h], respectively; P &amp;amp;lt; 0.001]. The 24-h PCA-meperidine consumption was significantly less in the Preincisional than in the Postincisional and Control groups (mean [SD]: 140 [60 mg], 390 [80 mg], and 570 [70 mg], respectively; P &amp;amp;lt; 0.001]. The incidence of postoperative hypoxemia (SpO(2) &amp;amp;lt; 90%) and nausea was significantly less in the Preincisional group (P &amp;amp;lt; 0.05). In conclusion, preincisional IM 120 mg dextromethorphan compared with the same postincisional dose significantly reduced postoperative meperidine consumption. IM administration of preincisional dextromethorphan (120 mg), allowing the use of a larger dose sufficient to block the central sensitization caused by activation of the N-methyl-D-aspartate receptors, provides preemptive analgesia and has a supportive role in postoperative pain relief, as shown by a significant decrease in 24-h meperidine consumption.

Research paper thumbnail of Prophylactic anti-emetic efficacy of ondansetron in laparoscopic cholecystectomy under total intravenous anaesthesiaA randomised, double-blind comparison with droperidol, metoclopramide and placebo

Anaesthesia, 1999

The prophylactic anti-emetic efficacy and safety of pre-operative intravenous ondansetron was eva... more The prophylactic anti-emetic efficacy and safety of pre-operative intravenous ondansetron was evaluated in a randomised, double-blind, comparison with droperidol, metoclopramide and placebo in 160 ASA grade 1 and 2 patients undergoing laparoscopic cholecystectomy under total intravenous anaesthesia. The patients were randomly allocated to receive ondansetron (4 mg), droperidol (1.25 mg), metoclopramide (10 mg) or placebo given as a single intravenous dose immediately before induction of a standardised general anaesthetic. There were no significant differences between the four study groups with regard to the demographic and anaesthetic data, postoperative analgesia, postoperative sedation scores, duration of postoperative hospital stay and incidence of adverse events. The incidence of nausea and vomiting was significantly lower (p`0.05) between 1 h and 4 h after surgery in the ondansetron group compared with the droperidol, metoclopramide and placebo groups. The incidence of nausea was similar in the four groups in the other study periods: 0-1 h and 4-24 h. The incidence of vomiting was lower in the ondansetron, droperidol and metoclopramide groups than in the placebo group between 1 and 4 h but was the same between 4 and 24 h. As a result of the lower incidence of nausea and vomiting between 1 h and 4 h in the ondansetron group, the overall incidence of nausea and vomiting was lower during the first 24 h after surgery in this group than in the other three groups.

Research paper thumbnail of The immunomodulatory effects of prolonged intravenous infusion of propofol versus midazolam in critically ill surgical patients

Anaesthesia, 2001

Both propofol and midazolam are known to inhibit immune function. The aim of this study was to in... more Both propofol and midazolam are known to inhibit immune function. The aim of this study was to investigate cytokine production in critically ill surgical patients as early markers of immune response to prolonged infusion of propofol and midazolam. The study enrolled 40 elective patients who were to receive long-term sedation for more than 2 days. Patients were randomly allocated to one of two equally sized groups. Central venous blood samples for measurement of interleukin-1b (IL-1b), interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-8 (IL-8), tumour necrosis factor-a (TNF-a) and interferon-g (IFN-g) were drawn prior to the start and after 48 h of infusion. After 48 h, propofol caused significant increases in IL-1b (24%), IL-6 (23%) and TNF-a (4.8 times) levels, while midazolam caused significant decreases in IL-1b (21%), IL-6 (21%) and TNF-a (19%). Both agents caused significant decreases in IL-8 levels (propofol: 30%, midazolam: 48%, p , 0.05). Propofol caused significant decreases in IL-2 levels (68%, p , 0.001) but increases in IFN-g (30%, p , 0.05), whereas there was no significant change with midazolam compared with the pre-infusion level. In conclusion, during 48 h of continuous infusion, propofol stimulated, while midazolam suppressed, the production of the pro-inflammatory cytokines IL-1b, IL-6 and TNF-a, and both caused suppression of IL-8 production. Propofol inhibited IL-2 production and stimulated IFN-g production, whereas midazolam failed to do so. Therefore, sedative agents may have clinical implications in high-risk and immunocompromised patients.

Research paper thumbnail of The effect of halothane and isoflurane on plasma cytokine levels

Anaesthesia, 2000

The aim of this study was to investigate the effect of halothane vs. isoflurane on cytokine produ... more The aim of this study was to investigate the effect of halothane vs. isoflurane on cytokine production during minor elective surgery. Forty adult patients, ASA I-II were randomly allocated to receive halothane or isoflurane. Venous samples for interleukin (IL)-1beta, IL-2, IL-6, tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) were taken before anaesthesia, before incision, at the end of anaesthesia and 24 h postoperatively. In both groups, IL-6 and TNF-alpha levels remained low throughout the study period. Before incision, in both groups IL-1beta and IFN-gamma showed a decrease (p&amp;amp;lt;0.01 for IL-1beta in isoflurane group and p&amp;amp;lt;0.05 for the others) compared with pre-induction. By the end of anaesthesia and surgery, IL-1beta had increased significantly (p&amp;amp;lt;0.05) and IFN-gamma had decreased significantly (p&amp;amp;lt;0.05) in both groups compared with pre-incisional levels. By 24 h postoperatively in both groups, IL-1beta had decreased significantly (p&amp;amp;lt;0.05), whereas IFN-gamma had increased significantly (p&amp;amp;lt;0.05) compared with the end of anaesthesia and surgery level. Pre-incisionally, IL-2 increased in the halothane group (p&amp;amp;lt;0.01), whereas it decreased significantly in the isoflurane group (p&amp;amp;lt;0.001) compared with the pre-induction level. By the end of anaesthesia and surgery and by 24 h postoperatively, IL-2 had decreased significantly in the halothane group (p&amp;amp;lt;0.001), whereas it increased significantly in the isoflurane group (p&amp;amp;lt;0.001) compared with pre-incision and end of anaesthesia and surgery levels, respectively.

Research paper thumbnail of The effect of anaesthesia and surgery on plasma cytokine production

Anaesthesia, 1999

The aim of this study was to investigate cytokine production in response to anaesthesia [total in... more The aim of this study was to investigate cytokine production in response to anaesthesia [total intravenous anaesthesia (TIVA) with propofol, sufentanil and atracurium] and surgery (laparoscopic vs. open cholecystectomy). Forty adult patients, ASA I-II, undergoing elective laparoscopic (group 1) or open (group 2) cholecystectomy were studied. Venous blood samples for measurement of interleukin (IL)-1b, IL-2, IL-4, IL-6, tumour necrosis factor-a (TNF-a) and interferon-g (IFN-g) were taken before the induction of anaesthesia, pre-incisionaly, at the end of anaesthesia and surgery and 24-h postoperatively. Pre-incisionaly, in both groups, IL-1b, IL-4, IL-6, TNF-a and IFN-g did not show a significant change, whereas IL-2 showed a significant decrease (p < 0.005 in group 1 and p < 0.001 in group 2) compared with pre-induction levels. By the end of anaesthesia and surgery, IL-1b, IL-2, IL-4, IL-6 and TNF-a showed a significant increase in group 2 (p < 0.005 for IL-1b, IL-2 and IL-4, and p < 0.05 for IL-6 and TNF-a); while in group 1, only IL-2 showed a significant increase (p < 0.01) and IFN-g showed a significant decrease (p < 0.05) compared with pre-incisional levels. By 24-h postoperatively, IL-1b, IL-4, IL-6 and TNF-a had decreased significantly in group 2 (p < 0.005 for IL-4 and p < 0.05 for the others); whereas in group 1, IL-2 and IFN-g showed a significant increase (p < 0.005) compared with the end of anaesthesia and surgery level. In conclusion, TIVA with propofol, sufentanil and atracurium does not seem to have a significant effect on IL-1b, IL-4, IL-6, TNF-a and IFN-g release. IL-2 was the only cytokine to show a significant decrease due to the effect of anaesthesia alone in both groups. The cytokine response to open cholecystectomy stimulated both the pro-inflammatory (IL-1b, IL-6 and TNF-a) and the anti-inflammatory (IL-4) components, while this response was absent in laparoscopic cholecystectomy.