Dexmedetomidine, a centrally acting α2-adrenoceptor agonist, has been used as an adjunct to anesthesia and in sedation because of its efficient sympatholytic, analgesic, and anxiolytic properties. Recently, several studies have focused on the potential neuroprotective and renoprotective effects of dexmedetomidine in patients undergoing different surgical procedures.
Coronary artery bypass grafting (CABG) with cardiopulmonary bypass is associated with a high incidence of perioperative renal dysfunction that is believed to be caused partly by the increased sympathetic nervous system activity leading to compromised hemodynamics and attenuated renal function.
To test the hypothesis that dexmedetomidine would exert a renal protective effect and prevent the development of acute kidney injury in patients with mild to moderate renal dysfunction undergoing elective CABG during the early postoperative days.
A double-blind randomized placebo-controlled study was carried out. Eighty adult patients with mild to moderate renal impairment (serum creatinine between 1.5–2 mg/dl) and scheduled for elective CABG with cardiopulmonary bypass were randomly allocated to either dexmedetomidine infusion or placebo infusion groups. Infusion was started after induction of anesthesia and continued until the end of surgery. The primary outcome variables measured for assessment of renal functions included serum creatinine, creatinine clearance, and urinary output in the 72 h postoperatively.
No significant difference was detected for any indicators of renal function between both groups, except for an increase in urinary output in the dexmedetomidine infusion group in the first 24 h after surgery (P=0.007).
The use of dexmedetomidine infusion did not alter renal function in terms of serum creatinine or creatinine clearance but was associated with an increase in urinary output in the first 24 h.
Hepatorenal syndrome (HRS) is a functional renal failure complicating end-stage liver disease. Management of HRS is based on therapy with vasoconstrictors and albumin. The aim of this prospective, randomized, comparative study was to evaluate the efficacy of norepinephrine versus terlipressin in the management of patients with type 1 HRS refractory to treatment with octreotide, midodrine, and albumin.
This study included 60 patients with type 1 HRS refractory to treatment with octreotide, midodrine, and albumin for 72 h. Patients were randomized to receive norepinephrine or terlipressin plus albumin. The outcomes assessed were as follows: kidney functions, reversal of HRS, survival rate at day 30, and cost of the study medications.
The final statistical analysis included 51 patients; 26 in the terlipressin group and 25 in the norepinephrine group. Demographic data and baseline patient characteristics were comparable in the two groups. The incidences of HRS reversal were comparable in the two groups. In both groups, there was an improvement in kidney functions. The responders in both groups showed a significant improvement in kidney functions at the end of the study compared with baseline. There was a significant progressive decrease in serum creatinine (P⩽0.05) levels and a significant progressive increase in creatinine clearance (P⩽0.05) and urine output (P⩽0.05) compared with baseline. Both groups were comparable throughout the study. The survival rates at day 30 were comparable in the two groups. The cost of norepinephrine therapy was significantly lower than that of terlipressin therapy (57 560±16 870 vs. 13 492±7694 Egyptian pounds; P⩽0.05).
The results of this study suggested that norepinephrine is as effective as terlipressin in the management of patients with type 1 HRS.
Patients with long-standing mitral valve disease are at risk of developing pulmonary hypertension, which may present a formidable challenge for the cardiac anesthetist (perioperatively) during cardiac surgery. Pulmonary hypertension is an important risk factor for the development of acute right-sided heart failure during cardiac surgery. Even with early and adequate therapy, right ventricular (RV) failure is associated with increased morbidity and mortality. Adequate treatment of RV failure consists of different strategies. The main goal is to decrease RV afterload using vasodilating agents and reducing the pulmonary vascular tone. In this review, we will present an overview of the most recent management protocols used in the management of patients with secondary pulmonary hypertension.
This study was carried out to evaluate the effects of sildenafil in perioperative management of parturients with pulmonary hypertension undergoing cesarean section in Kasr El Aini hospitals.
Twenty-four parturients subjected to elective cesarean section were anesthetized with epidural anesthesia. Incremental doses (5 ml) of lidocaine (1%) and bupivacaine (0.25%) mixture (up to 20 ml) were administered to attain sensory block at the T4 level. Patients were randomized to receive either oral sildenafil 50 mg 1 h before anesthesia and then 25 mg three times daily postpartum for 1 month (sildenafil group) (n=12 patients) or placebo tablets (control group) (n=12 patients). An epicardial transthoracic echocardiography was performed postoperatively daily for 3 days and then after 1 month to obtain information on pulmonary blood pressure and ejection fraction (EF), hemodynamic parameters, and arterial blood gases analysis, and maternal and neonatal outcomes were compared between the groups.
There were no significant differences in mean arterial pressure and heart rate between the two groups or from the baseline. The sildenafil group showed a significant improvement in maternal oxygenation and the pulmonary artery pressure (PAP) decreased from 47.33±6.80 to 34.50±4.92 mmHg after 1 month of treatment. In the sildenafil group, EF increased from 56.00±1.95 to 62.83±3.80% after 1 month. However, in the control group, there were no statistically significant changes in maternal oxygenation, PAP, or EF. There were no significant differences between the two groups in neonatal outcomes using the APGAR score at 1 and 5 min.
The use of oral sildenafil has promising results in parturient with pulmonary hypertension as it is effective in improving maternal oxygenation, decreasing PAP, and increasing EF.
To investigate the analgesia of a continuous transversus abdominis plane (TAP) block over the first 24 postoperative hours in renal transplanted patients.
This prospective randomized study included 40 adult patients scheduled for living-related kidney transplantation. They were randomized into two equal groups: group I underwent a ultrasound-guided continuous TAP block with 20 ml bupivacaine 0.5% bolus, followed by a continuous infusion of 10 ml/h of bupivacaine (0.25%) for 24 h and group II received the same block with the same volume and infusion rate as isotonic saline. Pain at rest and on sitting, sedation, and nausea and vomiting were assessed at 2, 6, 12, and 24 h postoperatively. The total intraoperative analgesic requirement, time for the first request for analgesia, and total postoperative meperidine over 24 h were assessed.
Postoperative Visual Analogue Scale scores at rest were significantly lower in the Bupivacaine group between 2 and 12 h postoperatively and Visual Analogue Scale scores on movement were significantly lower in the Bupivacaine group at 2, 6, 12, and 24 h postoperatively. Postoperative sedation scores were significantly higher in the Control group at 4 and 6 h. The total meperidine requirement was significantly higher in the Control group (161±31 mg) compared with the Bupivacaine group (57±30 mg) (P<0.001). There was no significant effect of TAP on postoperative nausea.
TAP block appears to be a good alternative for postoperative analgesia following living-related kidney transplantation. It reduced pain scores and opioid consumption in the first 24 h.
The respiratory function is impaired in off-pump coronary artery bypass (OPCAB). This study was carried out to detect whether a positive end expiratory pressure (PEEP) is essential to improve lung compliance and arterial pressure of oxygen (PaO2) in patients undergoing OPCAB.
Sixty patients scheduled for undergoing OPCAB were randomized to receive either peak inspiratory pressure (PIP) at 30 cm H2O with PEEP at 10 cm H2O for 1 min, after which PIP was raised to 40 cm H2O together with PEEP at 15 cm H2O for another minute (group P) or PIP at 30 cm H2O for 1 min, followed by PIP at 40 cm H2O for another minute without any PEEP (group NP). Both lung compliance and PaO2 were measured at four time points: T1, after induction of general anesthesia; T2, before raising the PIP and PEEP; T3, 30 min after raising the PIP and PEEP; and T4, at the end of surgery. In the ICU, PaO2 was measured 30 min after admission to ICU (T5), 1 h after raising the PIP to 30 cm H2O (T6), and 4 h later (T7).
As regards pulmonary compliance and intraoperative and postoperative PaO2, there was no statistically significant difference between the two groups. However, the mean arterial pressure after applying PEEP was significantly lower in group P than in group NP, both during surgery and in the ICU (P<0.05).
Both recruitment strategies, PEEP and high PIP, are protective and tolerable in patients undergoing OPCAB.
Acute kidney injury (AKI) after cardiac surgery is associated with increased morbidity and mortality. The aim of the study is to assess the effect of N-acetylcysteine (NAC) on postoperative AKI in patients with rheumatic heart disease undergoing valve replacement while excluding other risk factors (clinical trials gov identifier NCT01704482).
In this prospective, randomized, placebo-controlled, double-blinded clinical trial, conducted in Assiut University Hospital, 60 patients with rheumatic valvular heart disease who underwent heart surgery were randomized to either group N (n=30) 24 h of high dose N-acetylcysteine infusion (300 mg/kg body weight in 5% glucose) or group C (n=30) equivalent volume of 5% glucose over the same period. The primary outcome was maximum change in creatinine from baseline within 5 days after surgery. The secondary outcome and other data collected were: operative time, bypass time, clamping time, intraoperative urine output, invasive mean arterial blood pressure (5 min after induction, before going on bypass, lowest on bypass and before discharge to ICU), colloids and crystalloids given at the first 24 h, blood products given in the first 48 h, furosemide for the first 48 h, urine output for the first 48 h post-operatively, duration of mechanical ventilation, length of ICU stay and hospital stay.
Creatinine increased in both groups (32.26±29 μmol/l in group N vs. 39.97±29.38 μmol/l in group C, P=0.32) and peaked on postoperative day 3. Acute kidney injury occurred in 25 patients (9 patients in group N vs. 16 patients in group C; P=0.07). There was no difference in lengths of stay in the intensive care unit, hospital stay, and duration of mechanical ventilation. There were no significant differences between both groups as regard operative time, bypass time, clamping time, intraoperative urine output, invasive mean arterial blood pressure, colloids and crystalloids given at the first 24 h, blood products given in the first 48 h, furosemide for the first 48 h and urine output for the first 48 h post-operatively.
NAC was no more effective than placebo in decreasing acute renal dysfunction in patients with Rheumatic Heart disease undergoing valve replacement.