Surgical Field Conditions Research Articles

A comparative study between dexmedetomidine versus magnesium sulphate for controlled hypotensive anesthesia in rhinoplasty surgeries

Background: Rhinoplasty, a widely performed surgical procedure globally, necessitates hypotensive anesthesia to minimize bleeding, which can otherwise compromise surgical outcomes. Controlled hypotension anesthesia enhances the bloodless surgical area, reduces postoperative edema and ecchymosis, and can shorten the duration of the procedure. Many drugs have been used to attain hypotensive anesthesia, including magnesium sulfate, volatile anesthetics, and beta-adrenergic blocking agents. We compared dexmedetomidine with magnesium sulfate for producing hypotensive anesthesia in patients undergoing rhinoplasty. Methodology: We included 42 patients, aged 18-60 y, undergoing rhinoplasty and allocated into Group D and Group M. Group D received dexmedetomidine 1 µg/kg diluted in 50 mL of normal saline, administered IV over 10 min prior to anesthesia. Group M received magnesium sulfate 40 µg/kg diluted as infusion. Both groups received continued infusions afterwards. General anesthesia was induced with propofol and atracurium, intubation done and maintained on sevoflurane in N2O and O2. Vital signs were monitored continuously. The efficacy of hypotensive anesthesia was assessed, along with the recording of postoperative complications and the surgeons’ satisfaction. Results: Group D and Group M showed no significant variation in mean arterial pressure. However, significant variation was observed in heart rate (P < 0.05). Group D had better operating area score compared to Group M. Surgeons; satisfaction was notably elevated in the Group D than in the Group M (P < 0.05). Opioids needed were significantly less in the Group D in contrast to the Group M. The amount of atropine needed was higher in the Group D than in the Group M (P < 0.05). Conclusion: Dexmedetomidine proved to be better than magnesium sulfate in achieving hypotensive anesthesia together with providing optimal surgical field conditions. Although magnesium sulfate necessitated additional nitroglycerine, dexmedetomidine increased the risk of bradycardia but reduced the analgesic requirements compared to magnesium sulfate. These factors are crucial when considering the use of dexmedetomidine in rhinoplasty surgery. Trial Registry: PACTR202408620568675. Keywords: hypotensive anesthesia; magnesium sulphate; dexmedetomidine Citation: Abd Elhalem SAA, Ahmed Abd ElAala El-Shawarby AE, Hakim KYK, Abdel Rahman YA, Khalifa AAG. A comparative study between dexmedetomidine versus magnesium sulphate for controlled hypotensive anesthesia in rhinoplasty surgeries. Anaesth. pain intensive care 2024;28(5):894−900; DOI: 10.35975/apic.v28i5.2537 Received: August 21, 2024; Reviewed: September 6, 2024; Accepted: September 9, 2024

Comparative evaluation of oral premedication with clonidine and metoprolol on surgical field conditions and intraoperative hemodynamics during functional endoscopic sinus surgery

Abstract Background and Aims: Bloodless surgical field during functional endoscopic sinus surgery (FESS) is an essential part, and research continues to find simple and effective regime for it. This study was aimed to compare the efficacy of oral clonidine versus oral metoprolol as premedicants regarding surgical field condition and controlled hypotension in patients undergoing FESS. Material and Methods: Sixty-eight patients of American Society of Anesthesiologists (ASA) physical status (PS) I and II aged 18–60 years, of both genders, scheduled for FESS under general anesthesia were randomly allocated in two groups. Group C (n = 34) received oral clonidine 300 μg and group M (n = 34) received oral metoprolol 50 mg, 2 h before surgery. Controlled hypotension (mean arterial pressure [MAP] 65–75 mmHg) was achieved by titrating sevoflurane (1%–3%). Primary outcome measured was surgical field visualization by Average Category Scale (ACS 0–5), and the secondary outcomes measured were hemodynamic parameters, sevoflurane requirement, recovery, and side effects. Categorical, continuous, and ordinal data were compared using Chi-square test, t-test, and Mann–Whitney test, respectively. P < 0.05 was considered as statistically significant. Results: ACS was significantly less in group C compared to group M up to 60 min, (P < 0.05). Mean systolic blood pressure (SBP), diastolic blood pressure (DBP), and MAP were significantly less in group C compared to group M at all time intervals (P < 0.05) Intraoperative sevoflurane requirement (vol %) was significantly less in group C (1.21 ± 0.42) compared to group M (1.68 ± 0.53) (P = 0.000). Conclusions: Premedication with oral clonidine was found to be superior to oral metoprolol as it provided significantly better surgical field condition during FESS with much efficient controlled hypotension and anesthetic-sparing effect. Standardized Study Reporting Requirements: CONSORT: http://www.consort-statement.org/.

A prospective-randomized placebo-controlled trial comparing the effects of nebulized dexmedetomidine v/s dexmedetomidine-lignocaine mixture on intraoperative hemodynamics and surgical field quality in patients undergoing endoscopic transnasal transsphenoidal pituitary tumor surgery

Background: During transnasal transsphenoidal pituitary surgery (TNTSS), the primary objective is to maintain stable hemodynamics while ensuring ideal surgical conditions. This study aimed to investigate the effect of nebulized dexmedetomidine on hemodynamic parameters and the quality of the surgical field during TNTSS. Methods: Seventy-five patients scheduled for TNTSS were randomized into three groups of 25 each and received preoperative nebulization with 5 mL of nebulizing fluid consisting of 1.5 μg/kg of dexmedetomidine with saline in dexmedetomidine (D) group; 1.5 μg/kg of dexmedetomidine with 2% lignocaine in dexmedetomidine-lignocaine (DL) group and normal saline in the control (S) group. Heart rate (HR), mean blood pressure, Formmers score, anesthetic requirement, and emergence were evaluated for each group. Results: Group S had significantly higher HR and mean arterial pressure than the other two groups across various time points during surgery (P < 0.01). The total requirements for fentanyl, propofol, sevoflurane, and labetalol and the incidence of delayed emergence were significantly higher in the S group compared to the other two groups (P < 0.01). The D and DL groups exhibited significantly better surgical field conditions than the S group. In all the parameters assessed, patients in the D group outperformed those in the DL group. Conclusion: The administration of nebulized dexmedetomidine, both alone and in combination with lignocaine, resulted in stable hemodynamics, favorable operative conditions, reduced anesthetic requirement, and facilitated prompt emergence during TNTSS. Nebulized dexmedetomidine proved superior to its combination with lignocaine across all evaluated parameters.

Propofol versus Desflurane in Moyamoya Disease Patients-A Pilot Study.

Objectives The choice of inhalational or intravenous anesthetic agents is debatable in neurosurgical patients. Desflurane, a cerebral vasodilator, may be advantageous in ischemic cerebral pathologies. Hence, we planned to compare desflurane and propofol in patients with moyamoya disease (MMD) with the objective of comparing neurological outcomes. Materials and Methods This prospective pilot trial was initiated after institutional ethics committee approval. Patients with MMD undergoing revascularization surgery were randomized into two groups receiving either desflurane or propofol intraoperatively. Neurological outcomes were assessed using a modified Rankin score (mRS) at discharge and an extended Glasgow outcome score (GOS-E) at 1 month. Intraoperative parameters, including hemodynamic parameters, end-tidal carbon dioxide, entropy, intraoperative brain relaxation scores (BRS), and rescue measures for brain relaxation, were compared. Statistical Analysis The normality of quantitative data was checked using Kolmogorov-Smirnov tests of normality. Normally distributed data were compared using unpaired t -tests, skewed data using Mann-Whitney U tests, and categorical variables using chi-squared tests. Results A total of 17 patients were randomized, 10 in the desflurane and 7 in the propofol group. mRS (1.3 ± 0.6 and 1.14 ± 0.4, p = 0.450) and GOS-E (6.7 ± 0.6 and 6.85 ± 0.5, p = 0.45) were comparable between desflurane and propofol groups, respectively. BRS was significantly higher in the desflurane group (3.6 ± 0.5) compared to the propofol group (2.1 ± 0.3, p = 0.001), with a significant number of patients requiring rescue measures in the desflurane group (70%, p < 0.001). Other outcome parameters were comparable ( p > 0.05). Conclusion We conclude that postoperative neurological outcomes were comparable with using either an anesthetic agent, desflurane, or propofol in MMD patients undergoing revascularization surgery. Maintenance of anesthesia with propofol had significantly superior surgical field conditions.

Perioperative outcome of ultrasound-guided pterygopalatine fossa block in functional endoscopic sinus surgery: A randomized controlled trial

ABSTRACT Background Ultrasound (US)-guided pterygopalatine fossa (PPF) block helps to improve the field of surgery and control hemodynamic fluctuations during functional endoscopic sinus surgery (FESS). Patients and methods 120 eligible patients (60 per group) members of the American Society of Anesthesiologists class I or II aged 18 to 50 were randomly classified by closed envelope method. Group C: Patients in the control group received only general anesthesia (GA). Group PFB: Patients received bilateral PPF block with 4 ml 0.25% bupivacaine after induction of GA. Results Heart rate (HR) was significantly lower in PFB than in the control group at 15 min after induction of GA to 105 min intraoperatively. Between the two groups, there was no statistically significant difference in mean arterial blood pressure (MABP). Fentanyl and propranolol were less significantly used intraoperatively in the PFB group. Nitroglycerine was not needed in the PFB group while ten patients in group C received it. The total intraoperative isoflurane consumption and the mean consumption per minute used intraoperatively were significantly higher in the control group. There was a significant statistical difference between the two groups at 15 min only where the endoscopic surgical field condition in group PFB was more visible than in group C. The mean time to extubation and recovery time in group C was significantly longer than in group PFB. Conclusion US-guided PPF block controls the hemodynamics and improves surgical field conditions during FESS, reduces perioperative anesthetics consumption, and enhances good recovery patterns.

Randomized comparison of effects of two different remifentanil dose on surgical conditions during endoscopic sinus surgery

BackgroundThe combination of propofol and remifentanil results in better surgical field conditions during endoscopic sinus surgery than inhalation anesthesia. This study compared surgical field conditions between two groups receiving low or high concentration of remifentanil and hemodynamic variables using non-invasive cardiac monitoring.MethodsFifty-four patients between ASA I or II, were randomly assigned to either the high-concentration remifentanil group (HR), effect-site concentration of 8 ng/mL or the low-concentration remifentanil group(LR), effect-site concentration of 4 ng/mL. Surgical condition was evaluated using the Boezaart Surgical Field Grading Scale presented by Boezaart. Cardiac output was measured using non-invasive cardiac monitoring (CSN-1901).ResultsIn terms of surgical conditions, the HR group showed significantly lower values than the LR group (p = 0.021) at 90 min after the start of surgery. Heart rate was significantly lower in the HR group than the LR group at 30, 60, and 90 min after the start of surgery (30 min; p = 0.005, 60 min; p = 0.002, 90 min; p = 0.001). There was a statistically significant decrease of cardiac output in the HR group compared to the LR group immediately after endotracheal intubation and at 30, 60, and 90 min after the start of surgery (Base; P = 0.222, Intubation; P = 0.016, 30 min; p = 0.014, 60 min; P = 0.012, 90 min; P = 0.008). However, in the case of stroke volume, there was no significant difference between the two groups in all measurements.ConclusionWhen comparing the HR group and the LR group, the surgical condition was improved at 90 min after the start of surgery. MAP was lower in the HR group and this was a result of reduction in cardiac output primarily attributed to the decrease in heart rate rather than a decrease in stroke volume.Trial registrationClinical Trial Registry of the Republic of Korea (KCT0006453).

Controlled Hypotension for Functional Endoscopic Sinus Surgery With Two Different Doses of Fentanyl.

Background and Objectives Functional endoscopic sinus surgery (FESS) is a type of minimally invasive surgery done for acute and chronic sinus diseases or paranasal illnesses. The idea of FESS is to preserve the normal anatomy, which is non-obstructing and mucous membranewhile removing tissue obstructing OMC (osteo metal complex) and facilitating drainage. The critical structures, including the brain, orbit, and carotid veins, the lack of adequate operating room, and bleeding that obscures endoscopic vision throughout the procedure may increase the likelihood of unfavorable surgical results.This study seeks to examine the hemodynamic effects of intubation and extubation as well as the impact of fentanyl infusion on lowering blood pressure during FESS procedures. Materials and Methods Sixty-eight patients from the American Society of Anesthesiologistsclasses 1 and 2 who were planned for functional endoscopic sinus operations were randomly split into two groups for this randomized prospective trial. Group 1 patient belonging to the fentanyl 2 mcg per kg bolus 30 minutes before induction followed by 2 mcg per kg per hr infusion for 90 minutes of surgery, and Group 2 patient belonging to fentanyl 1 mcg per kg bolus 30 minutes before induction followed by 1 mcg per kg per hr infusion for 90 minutes of surgery. The significance of the difference in quantitative measures was measured using the student-t test, and the Chi-square test was used to measure upthe difference in proportion. Statistically significant was set at P<0.05. Results Mean systolic blood pressure was higher in members of Group 2 than in Group 1. In contrast to Group 2, Group 1 had considerably better surgical field conditions, surgeon satisfaction on the AONO'S scale, post-operative nausea and vomiting, and a post-operative VAS Score during the first 24 hours. Conclusion Pre-induction Fentanyl with infusion can effectively control hypotension during functional endoscopic sinus surgery.

ASSESSMENT OF TOTAL INTRAVENOUS ANAESTHESIA BY PROPOFOL AND INHALATIONAL ANAESTHESIA WITH ISOFLURANE FOR CONTROLLED HYPOTENSION IN FUNCTIONAL ENDOSCOPIC SINUS SURGERY

Objective: The key objective of the study is to compare the Propofol-based total intravenous anaesthesia (TIVA) with Isoflurane-based inhalational anaesthesia for controlled hypotension during functional endoscopic sinus surgery (FESS). Materials and Methods: This is a prospective randomized, controlled single-blinded clinical study. The study involved 40 patients posted for elective FESS surgery, selected randomly from the ENT department. Anesthesia was induced with Inj. Midazolam 2 mg, Inj. Fentanyl 2 µg/kg, Inj. Propofol 2 mg/kg, Inj. Vecuronium 0.1 mg /kg and ventilated using oxygen, air, and Isoflurane (FiO2 of 0.5) in isofurane group patients. Injections of 2 mg of midazolam, 2 µg/kg of fentanyl, 2 mg/kg propofol, and 0.1 mg /kg vecuronium, as well as oxygen and air for ventilation, were used to induce anaesthesia (FIO2 of 0.5) in TIVA group patients. Fromme boezaart scale was used as an evaluation scale for surgical site bleeding. Results: The average blood loss in the isoflurane group was 134.25 ± 4.65ml and in the propofol group was 66.95 ± 4.28ml. The quality of the surgical field in the propofol group is (3.13 ± 0.9), and the isoflurane group is (3.13 ± 0.8). The results are significant. Conclusion: Total intravenous anesthesia using propofol provides notable advantages over the traditionally used inhalational anesthetic technique using isoflurane in surgical field conditions and intraoperative blood loss.

Modified Two-Surgeon Technique for Laparoscopic Liver Resection.

While minimizing intraoperative blood loss during liver resection is one of the most important tasks, it is more difficult to control the refractory bleeding during laparoscopic liver resection than with an open approach. We herein provide a modification of the two-surgeon technique that enables laparoscopic liver parenchymal transection to be performed as quickly and securely as open liver resection. To achieve proper "role sharing," the "transection mode" and the "hemostatic mode" are independent sets in place in this procedure, and these modes are switched rigidly according to the surgical field condition. By thoroughly sharing the roles, rapid laparoscopic liver parenchymal transection comparable to open liver resection can be accomplished. The present modified approach achieves satisfactory transection and hemostasis of the liver parenchyma and is also advantageous for teaching young surgeons and the entire surgical team.

Effect of preoperative systemic corticosteroids on intraoperative bleeding during sinonasal polyposis surgery

This prospective study was done to evaluate the effect of preoperative systemic corticosteroids on intraoperative bleeding during sinonasal polyposis surgery. Materials and Methods: A Total of 70 patients with age between 10-60 years were studied from the in-patient department. All the cases meeting the inclusion and exclusion criteria underwent Diagnostic Nasal endoscopy, CT scan and were divided into 2 groups of 35 each. Group A (35) received oral prednisolone 1mg/kg/day for 5 days prior to surgery and Group B (35) severed as control. The patients were operated under general anaesthesia, the bleeding volume and surgical field visibility was recorded. Postoperatively patients were followed up once weekly for 4 weeks. Results: Better surgical field conditions were the results of the powerful anti-inflammatory and antiedematous activity of the drug, which facilitated blood and secretion evacuation from the operated area providing a better surgical field visibility. Conclusion: In conclusion pre-operative administration of oral steroids reduces intra-operative bleeding and early post-operative complications.

Effect of Different Loading Doses of Dexmedetomidine on Controlled Hypotension and the Incidence of Bradycardia During Rhinoplasty: A Clinical Trial.

Controlled hypotension, with a mean arterial pressure (MAP) of 60 mmHg - 70 mmHg, provides a bloodless and visible surgical field during rhinoplasty. It has been shown that dexmedetomidine, an α2-adrenoreceptor agonist, is a suitable choice in this regard. One of the disadvantages of this drug is the possibility of severe bradycardia during infusion. Therefore, we compared lower intravenous (IV) loading doses to determine whether the hypotensive effect of the drug was preserved and the bradycardia incidence decreased. In this randomized, double-blinded clinical trial, 81 patients aged 18 to 50 years with the American Society of Anesthesiologists physical status (ASA-PS) class I and II, scheduled for rhinoplasty randomly received 1.0, 0.9, and 0.8 µg/kg (named as groups 1.0, 0.9, and 0.8, respectively) of IV dexmedetomidine before the induction of anesthesia followed by infusion (0.3 - 0.7 µg/kg/h) during operation. The patients’ heart rate (HR), MAP, the requirements for nitroglycerin (NTG) and extra fentanyl, as well as the incidence of bradycardia, were recorded. Bleeding and visibility of the surgical field were scored by the surgeon using a 6-point visual scale. MAPs, HRs, and consumption of NTG and extra fentanyl were similar in the studied groups. The surgical field was more visible and bloodless in group 1.0 compared to group 0.8 (P < 0.001); the differences were not significant between groups 1.0 and 0.9 (P = 0.605). The incidence (P = 0.027) and the severity of bradycardia (P = 0.017) were higher in the groups with higher loading doses. We concluded that dexmedetomidine is an acceptable agent to provide controlled hypotension. A loading dose of 0.9 µg/kg, but not 0.8 µg/kg, provides similar surgical field conditions as the dose of 1 µg/kg. Furthermore, despite the decrease in the incidence of bradycardia, the hypotensive effect of the drug is preserved.

Comparisons of surgical conditions of deep and moderate neuromuscular blockade through multiple assessments and the quality of postoperative recovery in upper abdominal laparoscopic surgery

Study objectiveTo determine the effect of deep neuromuscular blockade (NMB) on surgical field conditions through multiple assessments during pneumoperitoneum and evaluate the effect of the depth of intraoperative NMB on the quality of postoperative recovery over multiple time periods. DesignProspective randomized study. SettingOperating room of a university hospital. PatientsEighty non-morbidly obese patients (ASA physical status 1–2) who were scheduled to undergo laparoscopic gastrectomy in the reverse Trendelenburg position. InterventionsPatients were allocated to either the deep or moderate NMB group. The depth of NMB was maintained at a post-tetanic count of 1 for deep NMB with a continuous infusion of rocuronium and at a train-of-four count of 1 for moderate NMB with a small intermittent bolus of cisatracurium. MeasurementsSingle-blinded scoring of the quality of the surgical field condition was performed by a surgeon using a five-point scale in a 15-min interval during pneumoperitoneum. The quality of postoperative recovery was assessed using the Postoperative Quality of Recovery Scale (PostopQRS) on the day before surgery (baseline) and 1 h, 1 day, and 6 days after surgery. Main resultsOptimal surgical field condition was rated in 87.0% (449/516) and 72.3% (370/512) of all measurements during deep and moderate NMB, respectively (P < 0.001). The percentage of patients maintaining a good-to-optimal condition throughout pneumoperitoneum was higher in the deep NMB group than in the moderate NMB group. There were no significant differences in the percentage of recovered patients between the two groups for all domains and all timepoints. ConclusionsMultiple assessments of the surgical field condition demonstrated that deep NMB provided a more satisfactory surgical field condition than moderate NMB during laparoscopic gastrectomy. However, the quality of postoperative recovery, assessed using the PostopQRS, was not different between the two groups according to the depth of NMB.

Comparison of different methods of general anaesthesia for controlled hypotension in functional endoscopic sinus surgery (FESS)

Introduction and Aims: Functional Endoscopic Sinus Surgery (FESS) is minimal invasive technique for management of chronic sinusitis. Controlled hypotension is required in FESS for bloodless field, better visualization, reduce operative time and bleeding. Various agents like ? blockers, ?+? blockers, magnesium sulfate etc. used to achieve controlled hypotension. The aim of study was to produce controlled hypotension with propofol and isoflurane and to compare intraoperative blood loss, duration of surgery, operative field condition. Materials and Methods: Sixty patients were assigned in either group by computer generated random number table. Patients in Group A received propofol infusion and in group B received isoflurane in concentration to achieve MBP between 60 to 70 mmHg. Bispectral index value was also maintained between 40 to 60. Statistical difference between two groups was determined using unpaired student t test except for surgical field condition, for which Median test for two populations was used. A “p” value Result: There was no statistically significant difference in MBP between both groups. Mean intra-operative blood loss was less in group A (115.17±12.07 ml) compared to group B (140.5±15.83 ml). Mean duration of surgery was shorter in group A (109±9.32 min) compared to group B (131.67±12.82 min). Operative field condition was better in Group A compared to Group B (p=0.0026). Conclusion: Both propofol and isoflurane effective in producing controlled hypotension, but anaesthesia with propofol is associated with less blood loss, shorter duration of surgery and better surgical field condition compared to isoflurane. Keywords: Bispectral Index, Controlled hypotension, Functional endoscopic sinus surgery, Isoflurane, Propofol.

Comparison of Labetalol and Nitroglycerine,s Effects on Deliberate Hypotension in Septo-Rhinoplasty Ssurgery, a Randomized Clinical Trial

Introduction:Bleeding during ENT surgeries may contribute to impaired view. The less blood in surgical filed, the better quality and more surgeon�s satisfaction is expected. Deliberate hypotension is a technique to achieve this goal. Current study aimed to evaluate effects of Labetalol andNitroglycerinein deliberate hypotension. Methods: It is a double blind RCT,conducted on 68 septo-rhinoplastypatients in ENT ward, Imam Reza Hospital, Mashhad, during 2017 after obtaining written consent. Patients were assigned to receive Nitroglycerine (n=32) or Labetalol (n=36) randomly. Mean arterial pressure and HR monitored. Total blood loss was estimated and recorded at a Boezaart Surgical Field Grading Scale. Surgeon�s satisfaction with surgical field condition was measured after the procedures using a questionnaire at a 5-point Likert scale. Results: Two studied groups were similar in demographic characteristics. Heart rate was lower in Labetalol group (P <0.001) significantly, but there was no significant difference between two groups regarding mean arterial pressure variations (P = 0.12). Surgeon�s satisfaction with the operation condition was not significantly different (P= 0.28). According to Boezaart scale, no statistically significant difference was found between groups with regard to bleeding volume (P= 0.75). Patients in Labetalol group received less additive drugs to maintain hypotension than another group (P=0.025). Conclusion: Although Labetalol and Nitoglycerine are not much different in reducing blood loss or providing a better view of surgical field but Labetalol is superior in maintaining heart rate and hypotension and noneed toadditive drug.

Dexmedetomidine versus remifentanil infusion for controlled hypotension in shoulder arthroscopy: a comparative study

Study objectiveThe correct performance of the shoulder arthroscopic technique requires appropriate visualization through a video camera which raises the need for providing satisfactory bloodless surgical field. The current study was conducted to evaluate the clinical efficacy of dexmedetomidine infusion compared to that of remifentanil for controlled hypotension in patients undergoing shoulder arthroscopy.Patients and methodsForty patients undergoing elective arthroscopic shoulder surgery under general anesthesia were enrolled in the current study. Patients were randomly distributed into one of two equal groups: dexmedetomidine group (D group) and remifentanil group (R group) according to the agent used for controlled hypotension. In group D, IV dexmedetomidine l μg/kg was infused over 10 min before anesthesia induction, followed by a continuous infusion of 0.3-0.6 μg/kg/h during the operation. In group R, 1 μg/kg remifentanil IV bolus was administered before induction of anesthesia and continued 0.25-0.50 μg/kg/min during the operation. In both groups, the drug infusion was titrated to achieve a mean arterial pressure (MAP) of 60-70 mmHg. Hemodynamic parameters, surgical field condition, recovery profile, and the incidence of perioperative adverse events were assessed.ResultsControlled hypotension was achieved successfully in both study groups. There was no intergroup significant difference as regards the intraoperative MAP and heart rate (HR) recordings (P > 0.05) except for the significantly lower HR recorded after extubation,30 min and 1 h postoperative in group D when compared with group R (P < 0.05). The surgical field condition was satisfactory on surgeon assessment in both groups (P > 0.05). Extubation time, time to reach modified Aldrete score ≥ 9 and time to 1st postoperative analgesic requirement were significantly longer in the group D when compared with group R (P < 0.05). Postoperative Ramsay sedation score recordings were significantly higher in the group D when compared with group R (P < 0.05) except at 2 h postoperative recordings and all the VAS score recordings were significantly lower in group D when compared with group R (P < 0.05). There was no intergroup significant difference as regards the incidence of perioperative adverse events.ConclusionBoth remifentanil and dexmedetomidine can induce adequate levels of hypotensive anesthesia and satisfactory surgical field visibility in patients undergoing shoulder arthroscopy under general anesthesia. Patients treated with dexmedetomidine had better quality and more extended postoperative analgesia but longer postoperative anesthesia recovery and higher postoperative sedation scores when compared with remifentanil.

A Comparative Study between Nitroglycerin and Magnesium Sulfate during Shoulder Arthroscopic Surgery in the Beach Chair Position

AbstractBackground: This study was designed to compare the efficacy of intravenous infusion of nitroglycerin versus mag-nesium sulfate for controlled hypotensive anesthesia during arthroscopic shoulder surgery in Beach Chair Position (BCP).Aim of Study: To compare the efficacy of nitroglycerin versus magnesium sulfate in inducing deliberate hypotension and satisfactory surgical field in patients undergoing arthro-scopic shoulder surgery.Material and Methods: Fourty patients scheduled for arthroscopic shoulder surgery under general anesthesia in BCP, randomly assigned into two equal groups, nitroglycerin group (NTG group, n=20) received infusion of 0.5-5μg/kg/min and magnesium group (Mg group, n=20) received 40mg/kg, as slow bolus before induction in 100mL saline solution over 10min then 15mg/kg/h by infusion during the operation to achieve a mean arterial blood pressure (MAP) of about 50 to 65mmHg.Results: Controlled hypotension was achieved in both groups. There was no significant difference in MAP between two groups in first 30mins after infusion then magniseum group produced significantly lower MAP values till stopping of infusion. Heart Rate (HR) was significantly lower in mg group compared with the NTG group. More patients required fentanyl consumption intraoperative (p<0.0001) and frequent administration of rocuronium (p=0.001) in NTG group. How-ever, there was longer extubation time and recovery time in Mg group compared with the NTG group. Bleeding score was insignificantly lower in Mg group and surgeon's satisfaction score was significantly better (p=0.035) in the Mg group.Conclusions: Nitroglycerin and magnesium sulfate can effective in achieving hypotensive anesthesia during arthro-scopic shoulder surgery. However, MgSO4 provide a favorable surgical field condition and better surgeon's satisfaction.

Pre-induction fentanyl dose-finding study for controlled hypotension during functional endoscopic sinus surgery.

Background and Aims:Fentanyl can facilitate controlled intraoperative hypotension by its sympatholytic effect in patients undergoing functional endoscopic sinus surgery (FESS). We investigated the effects of different doses of pre-induction fentanyl on controlled hypotension profile during FESS.Methods:This prospective, randomised study included 120 patients randomly allocated to three groups (40 each) based on administration of pre-induction fentanyl; 2 μg/kg group, 3 μg/kg group and 4 μg/kg group. The primary objective was to assess effect on intraoperative heart rate and mean arterial pressure. Use of additional hypotensive agents, surgical field condition and surgeon satisfaction were also analysed.Results:Controlled hypotension was achieved adequately in all participants. Patients belonging to fentanyl 4 μg/kg group had significantly lower heart rate for the duration of controlled hypotension intraoperatively versus fentanyl 2 μg/kg group (P < 0.05). Trinitroglycerin [TNG] and metoprolol were administered to 3 [7.5%] and 9 [22.5%] patients respectively in the fentanyl 3 μg/kg group, and to 3 [7.5%] and 5 [12.5%] patients respectively in the 4 μg/kg group, compared to 14 [35%] and 20 [50%] in the fentanyl 2 μg/kg group, respectively (TNG, P < 0.001). Surgical field conditions and surgeon satisfaction scores were significantly superior in fentanyl 3 μg/kg and 4 μg/kg groups than in fentanyl 2 μg/kg group.Conclusion:Pre-induction fentanyl 3 μg/kg and 4 μg/kg group showed superior controlled hypotension facilitation than 2 μg/kg fentanyl during FESS in terms of measurable haemodynamic endpoints and favourable operative conditions, surgeon's satisfaction and sparing of additional hypotensive agents.

Unilateral cervical plexus block for prosthetic laryngoplasty in the standing horse.

Locoregional anaesthetic techniques can facilitate certain surgeries being performed under standing procedural sedation. The second and third spinal cervical nerves (C2, C3) are part of the cervical plexus and provide sensory innervation to the peri-laryngeal structures in people; block of these nerves might permit laryngeal lateralisation surgery in horses. To describe the anatomical basis for an ultrasound-guided cervical plexus block in horses. To compare this block with conventional local anaesthetic tissue infiltration in horses undergoing standing prosthetic laryngoplasty. Cadaveric study followed by a double-blinded prospective clinical trial. A fresh equine cadaver was dissected to characterise the distribution of C2 and C3 to the perilaryngeal structures on the left side. A second cadaver was utilised to correlate ultrasound images with the previously identified structures; a tissue marker was injected to confirm the feasibility of an ultrasound-guided approach to the cervical plexus. In the clinical study, horses were assigned to two groups, CP (n = 17; cervical plexus block) and INF (n = 17; conventional tissue infiltration). Data collection and analyses included time to completion of surgical procedure, sedation time, surgical field conditions and surgeon's perception of block quality. We confirmed that C2 and C3 provided innervation to the perilaryngeal structures. The nerve root of C2 was identified ultrasonographically located between the longus capitis and the cleidomastoideus muscles, caudal to the parotid gland. The CP group was deemed to provide better (P<0.0002) surgical conditions with no differences in the other variables measured. Further studies with larger numbers of horses may be necessary to detect smaller differences in surgical procedure completion time based on the improved surgical filed conditions. For standing unilateral laryngeal surgery, a cervical plexus block is a viable alternative to tissue infiltration and it improves the surgical field conditions.

Controlled Hypotension During Rhinoplasty: A Comparison of Dexmedetomidine with Magnesium Sulfate.

ObjectiveThe current study aimed at comparing the efficacy of dexmedetomidine and magnesium sulfate to control blood pressure (BP) during rhinoplasty and the resultant effects on the quality of surgical field in terms of bleeding and visibility.MethodsThe current randomized, prospective, double-blind study was conducted on 60 patients aged 18 to 50 years classified as ASA (American Society of Anesthesiologists) physical status I who were candidates for rhinoplasty. Patients were randomly divided into 2 groups: (1) group Dex, received 1 µg/kg dexmedetomidine in 10 minutes before induction of anesthesia, followed by 0.4 - 0.6 µg/kg/hour during the maintenance of anesthesia, and (2) group Mg, received 40 mg/kg in 10 minutes before anesthesia induction followed by 10 - 15 mg/kg/hour during anesthesia maintenance. In both groups, the goal was to achieve a mean arterial pressure (MAP) of 60 - 70 mmHg. Hemodynamic variables, anesthetic, opioid, muscle relaxant requirements, and surgical field condition were recorded. Sedation score, time to reach modified Aldrete score ≥ 9, and adverse effects including nausea and vomiting (N&V) and shivering were recorded.ResultsControlled hypotension was achieved in both groups. There was no significant difference in MAP between the groups, but heart rate (HR) was significantly lower in the Dex group (P < 0.001), compared with that of the Mg group. Bleeding score was lower (P < 0.001) and surgeon’s satisfaction score was higher (P < 0.001) in the Dex group. More patients required fentanyl (P < 0.001) or nitroglycerin (P < 0.001) and the mean fentanyl (P = 0.005) or nitroglycerin (P < 0.001) required doses were higher in the Mg group. Patients in the Dex group required more frequent administration of cisatracurium (P = 0.004). Five patients in the Dex group versus no patients in the Mg group received atropine (P = 0.023). Ramsay sedation score and time to reach modified Aldrete score ≥ 9 were significantly higher in the Dex group (P < 0.001 and P < 0.001, respectively). The incidence rate of N&V and shivering were similar in both groups.ConclusionDexmedetomidine was more effective than magnesium to achieve controlled hypotension, and provide a favorable surgical field condition. However, dexmedetomidine also heightened the risk of induced bradycardia and prolonged sedation. These are 2 important points to consider when applying this drug as a hypotensive agent during operation.

A Novel Use of a Novel Drug: Preoperative Nasal Preparation with Dexmedetomidine for Transnasal Transsphenoidal Neurosurgery Approach in Skull Base Neurosurgery

Introduction Transnasal transsphenoidal (TNTS) approach is preferred for surgical excision of the pituitary gland. Despite its numerous merits, the TNTS approach creates wide fluctuations in hemodynamic parameters that are attributed to the routine application of adrenaline-soaked nasal packing and the intense noxious stimulus during the surgery. Aims To evaluate the effect of dexmedetomidine for preoperative nasal passage preparation on the surgical field visualization and hemodynamic profile of patients during TNTS surgery. Material and Methods Cotton strips soaked in dexmedetomidine were used for nasal preparation. The primary outcomes studied were the quality of surgical field visualization through the endoscope and the amount of bleeding that occurred while raising the nasal mucosal flap. The secondary outcomes assessed were the intraoperative anesthetic and analgesic requirement and the hemodynamic profile. Statistical Analysis Data from the study were summarized as mean and SD. Associations were tested using chi-square test for nonparametric data and for continuous variables ANOVA for repeated measures. A p-value &lt; 0.05 was considered as statistically significant and &lt; 0.01 as highly significant. SPSS 17.0 was used for analysis. Results Seventeen (85%) patients had a Formmer's score of 1, which was an excellent surgical field quality. Two (10%) patients had a Formmer's score of 2, and one (5%) had a Formmer's score of 3. There were no statistically significant variations in heart rate and blood pressure with reduced anesthetic requirement. Conclusion Intranasal dexmedetomidine provides good surgical field conditions with the added advantage of lesser hemodynamic fluctuations.