Is there a role for endothelin-1 in the hemodynamic changes during hemodialysis?

Background  The etiology of hemodialysis (HD)-induced hypotension and hypertension remains speculative. There is mounting evidence that endothelin-1 (ET-1) may play a vital role in these hemodynamic changes. We examined the possible role of intradialytic changes of ET-1 in the pathogenesis of hypotension and rebound hypertension during HD. Methods  The present study included 45 patients with end-stage renal disease (ESRD) on regular HD. They were divided according to their hemodynamic status during HD into three groups (group I had stable intradialytic hemodynamics, group II had dialysis-induced hypotension, and group III had rebound hypertension during HD). In addition, 15 healthy volunteers were included as a control group. Pulse and blood pressure were monitored before, during (every half hour), and after HD session. ET-1 level was measured at the beginning, middle, and end of HD. ET-1 was measured in the control group for comparison. Results  Pre-dialysis levels of ET-1 were significantly higher in dialysis patients compared to the controls (P < 0.001); however, they were comparable in the three HD groups. The post-dialysis ET-1 level was not changed significantly in group I compared with predialysis values (14.49 ± 2.04 vs. 14.33 ± 2.23 pg/ml; P = NS), while the ET-1 concentration decreased significantly in group II and increased in group III in comparison to predialysis values (8.56 ± 1.44 vs. 11.75 ± 2.51; 16.39 ± 3.12 vs. 11.93 ± 2.11 pg/ml, respectively; P < 0.001). Conclusion  Altered ET-1 levels may be involved in the pathogenesis of rebound hypertension and hypotension during HD.     

Analysis of intracranial pressure changes during early versus late percutaneous tracheostomy in a neuro-intensive care unit

Background  We aimed to investigate intracranial pressure (ICP) changes during early versus late bedside percutaneous tracheostomy (PT) in a neuro-intensive care unit (NICU). Methods  This study included 30 patients admitted to our NICU for head trauma, subarachnoid haemorrhage, intracerebral haematoma or brain tumour with a Glasgow Coma Score (GCS) less than 8. These patients also underwent ICP monitoring. Bedside PT was performed either early (within 7 days of ventilation) or late (after 7 days of ventilation) via the Griggs system. In all patients; ICP, systemic blood pressure, heart rate, oxygen saturation (Sat O₂) and arterial blood gases were recorded 5 min before the procedure, during skin incision, during tracheal cannulation, as well as 5 min and 10 min after the procedure. Findings  Thirty patients, 18 male and 12 female, with various intracranial pathologies between ages 18 and 78 (mean 38.7 ± 20) were identified. The admission GCS ranged between 4 and 11 (median 7). Physiological variables did not differ significantly between the two groups. In the early group, ICP values measured 5 min before the procedure, during skin incision, during tracheal cannulation, as well as 5 min and 10 min after the procedure were 15.1 ± 5.2, 22 ± 10.1, 28.4 ± 13.7, 17.3 ± 7.1, 13.8 ± 5.0 mmHg, respectively. In the late group, these values were 14.2 ± 4.5, 17.2 ± 5.5, 21.5 ± 8.0, 15.1 ± 5.3 and 12.4 ± 4.1 mmHg. There was no significant difference between the early or late groups in terms of ICP increases during these predetermined 5 time points. Conclusions  In patients with decreased intracranial compliance, a relatively minimally invasive procedure such as PT may lead to significant increases in ICP. The timing of PT does not seem to influence ICP, mortality, pneumonia or early complications. During the PT procedure, ICP should be closely monitored and preventive strategies should be instituted in an attempt to prevent secondary insult to an already severely injured brain.     

Metabolic Changes In Living Kidney Donors After Donation In University Malaya Medical Centre

The short- and long-term outcome of donations from living donors of kidneys (LKDs) remains controversial. Information regarding metabolic changes after donation in Malaysia remains limited despite Malaysia having the highest record prevalence of diabetes, obesity, and hypertension in Asia. There were 159 LKDs in our center from 2010 to 2020. We analyzed pre and post donation clinical data and laboratory results from 140 LKDs, retrospectively, from electronic medical records and looked for any metabolic changes. Among these 140 LKDs, 99 were women (70.7%), with a mean age of 47.23 ± 11.67 before donation. The median follow-up was 4 years (range, 2-6 years). Median body mass index increased from 24.35 kg/m² (range, 22.11-26.93) to 25.56 kg/m² (range, 22.78-28.57; Z=-3.934, P = .000) after donation. Prevalence of obesity increased from 24.18% to 30.77%. Only 2.8% of LKDs developed proteinuria postnephrectomy (P = .250). Serum creatinine increased from 60 mmol/L (range, 52-74) to 87 mmol/L (range, 74-108) 1 year after donation (P = .000), and the latest results decrease to 83 mmol/L (range, 73-101; P = .000). Systolic blood pressure increased from 127.83 ± 12.25 mm Hg to 131.30 ± 18.16 mm Hg, (t[97] = –2.012; P = .047); and prevalence of hypertension increased from 19.81% to 23.58% (P = .125), with 22.64% requiring treatment. We noted that 22.54% of the LKDs had dyslipidemia before donation, a number that increased to 50% after donation (P = .000). LKDs with hyperuricemia increased significantly from 7.92% to 34.65%, with uric acid level increasing from 311.94 ± 78.51umol/L to 381.87 ± 86.96 umol/L (t[94] = –10.805; P = .000). Fasting blood glucose and glycated hemoglobin level recorded no significant changes after donation. Post donation kidney function of LKDs compensated well and stable in short term. We noted statistically significant increment of weight, post donation body mass index, systolic blood pressure, uric acid, and lipids. We suggest prospective studies with longer follow-up and more subjects for clinical correlation.     

Sedation practices during high dose rate brachytherapy for children with urogenital and perianal rhabdomyosarcoma

BackgroundA novel concept for an organ-preserving treatment of pediatric urogenital and perianal rhabdomyosarcoma includes high dose rate brachytherapy following surgical tumor resection. For the duration of the brachytherapy of 6 days plus 2-day recovery break the patients are not allowed to move and are kept under deep sedation, which can lead to difficult weaning from mechanical ventilation, withdrawal, delirium, and prolonged hospital stay. The aim of this study was to evaluate a protocol which includes a switch from fentanyl to ketamine 3 days prior to extubation to help ensure a rapid extubation and transfer from PICU.MethodsPatients who underwent surgical tumor resection of rhabdomyosarcoma and subsequent brachytherapy were treated according to a standardized protocol. We evaluated doses of fentanyl, midazolam and clonidine, time of extubation, length of PICU stay and occurrence of withdrawal symptoms and delirium. We compared fentanyl dose at time of extubation, duration of weaning from mechanical ventilation and time to discharge from PICU with patients after isolated severe traumatic brain injury.ResultsTwentytwo patients (age 39.9 ± 29.8 months) were treated in our PICU to undergo brachytherapy. Extubation was performed 21.6 ± 13.5 h after the last brachytherapy session with an average fentanyl dose of 1.5 ± 0.5 µg/kg/h and patients were discharged from PICU 58.4 ± 30.3 h after extubation, which all is significantly lower compared to the control group (extubation after 88.0 ± 42.2 h, p < 0.001; fentanyl dose at the time of extubation 2.5 ± 0.6 µg/kg/h, p < 0.001; PICU discharge after 130.1 ± 148.4 h, p < 0.009). Withdrawal symptoms were observed in 9 patients and delirium in 13 patients.ConclusionA standardized analgesia and sedation protocol including an opioid break, scoring systems to detect withdrawal symptoms and delirium, and tapering plans contributes to successful early extubation and discharge from PICU after long-term deep sedation.     

Randomized blinded trial shows relative thrombocytopenia in natural orifice translumenal endoscopic surgery compared with standard laparoscopy in a porcine survival model

Background  Anecdotal reports of natural orifice translumenal endoscopic surgery (NOTES) procedures in patients are emerging. Whether the new procedure truly is less invasive is not known. Perioperative hematologic parameters during NOTES was compared with those during standard laparoscopy. Methods  For this study, 12 swine were randomized to transgastric peritoneoscopy with air or diagnostic laparoscopy using carbon dioxide. Arterial and venous catheters provided cardiopulmonary parameters and blood draws at baseline and up to 7 days postoperatively. The animals survived for 14 days. Data were analyzed by an investigator blinded to the procedure performed. Treatments were contrasted in terms of the mean outcome using a repeated measures linear model. Results  All experiments were successfully completed. No gastric leak or peritonitis resulted. One NOTES animal died of hemorrhagic gastritis on postoperative day 3 due to bleeding distant from the gastrotomy site. Two animals in the laparoscopy group and one animal in the endoscopy group experienced respiratory compromise requiring disinflation. A widening pulse pressure and lower bladder pressure were observed in the NOTES group compared with the laparoscopy group (p < 0.001). Pre- and postoperative laboratory results showed an increase in the white blood cell count (1,000/ml) from 16.83 ± 1.94 in the laparoscopy group and 15.17 ± 0.41 in the NOTES group at baseline to 24.17 ± 3.25 and 23.33 ± 3.88, respectively, on postoperative day 7, but no difference between the groups (p = 0.6). The platelet count (1,000/ml) showed a difference between the two groups, changing from 422.5 ± 97.49 to 446.33 ± 89.86 in the laparoscopy group and from 368 ± 105 to 299.5 ± 161.9 in the NOTES group (p = 0.03). Conclusion  Significant differences in measured but not clinically apparent parameters were encountered. A potentially significant thrombocytopenia clinically was encountered in the NOTES group. The physiologic impact of NOTES procedures beyond the absence of abdominal incisions should be investigated further. Presented at the 2nd international conference on NOTES, Boston, MA, 13–14 July, 2007.     

Le midazolam intraveineux comme agent hynotique d'une neuroleptanalgésie

42 patients are given, before any neuroleptanalgesia mixture, 0.2 mg · kg^?1 of IV midazolam. Pain during the injection is reported in two cases. The loss of conversation onset is 38 ± 18 seconds and of the lid reflex is 75 ± 43 seconds. The only clinical variation is a drop of the systolic blood pressure from 121.4 ± 19.5 mmHg to 114.8 ± 19.6 mmHg, p <0.005. Apnea occurs in nine patients (21 per cent). It lasts 29 ± 35 seconds. But in a steady ventilatory state, the minute ventilation, the tidal volume and the respiratory rate are unchanged from the control values. At the end of the procedure, the answer to simple orders and the space and time orientation come back after 10 ± 13 minutes and 33 ± 28 minutes. The punctured vein is free of any reaction up to the third day.In conclusion, midazolam is a useful hypnotic drug mainly in the debilitated patient.     

Comparison of unilateral renal artery embolization versus bilateral for treatment of severe refractory hypertension in hemodialysis patients

Objective

Hypertension in ESRD patients is common, and often refractory to common medical interventions. Bilateral renal embolization (BRE) is an alternative to nephrectomy in treating severe refractory hypertension in hemodialysis patients, but has drawbacks in residual renal function preservation and post-infarction syndrome. We evaluated the efficacy and safety of unilateral renal embolization (URE) for the treatment of severe refractory hypertension in hemodialysis patients.

Patients and methods

From January 2000 to May 2007, 16 hemodialysis patients with severe refractory hypertension were randomized to URE or BRE group, and received percutaneous transcatheter unilateral or bilateral renal embolization, respectively. The efficacy and complications of these two procedures were compared. The plasma renin activity (PRA), plasma angiotensin II, aldosterone and endothelin-1 (ET-1) were measured pre- and post-renal embolization in both groups.

Results

The procedures were completed successfully without severe immediate complications. The blood pressure decreased from 211/122 to 127/81 mmHg in URE group (P < 0.0001), and in BRE group from 208/117 to 124/76 mmHg (P < 0.0001) with significantly reduced need for antihypertensive medications. The residual renal function was reasonably kept and post-infarction syndrome was milder in URE group compared with BRE group. No activation of RAS was observed in this series and no RAS activity dynamic change occurred post-procedure. Decreased circulating ET-1 was accompanied with the lowering of blood pressure after the procedure (P < 0.0001).

Conclusions

Unilateral renal embolization is as effective as BRE in treating severe refractory hypertension in hemodialysis patients, with advantages over BRE in residual renal function preservation and milder post-infarction syndrome.     

Renal cell carcinoma and arterial hypertension

Background  The association between renal cell carcinoma and arterial hypertension has been the subject of various studies. These studies have not been consistent in clarifying the relationship between the two. Some authors contend that arterial hypertension is a consequence of renal cell carcinoma, which secretes vasoactive peptides. Others claim that arterial hypertension is a risk factor for the development of renal cell carcinoma. The purpose of our study is to assess if there is a direct connection between arterial hypertension and renal cell carcinoma. Methods  Out of 16,755 patients who were examined by ultrasonography, 40 were diagnosed with renal tumors. Of the 40 patients, 29 had malignant renal tumors, and 11 had benign renal tumors. These diagnoses were confirmed by CT scan, renal biopsy, and histology. Most of the patients with renal cell carcinoma (79.3%) had arterial hypertension. The group with benign renal tumors served as a control group. Out of the 29 patients with malignant renal cell carcinoma, 24 patients were treated with total nephrectomy, one had a partial nephrectomy, and four patients were too unwell for surgical intervention. In the group of those with benign renal tumors, seven patients had partial nephrectomies for the removal of angiomyolipomas. The personal histories were taken at the initiation of the study, and vital signs were obtained before and after surgery. Statistical analyses were performed using the Statistical Package for Social Sciences, version 10.0. Results  In the malignant group, the systolic blood pressure (SBP) before surgery was 157.41 ± 27.86 mmHg, and the diastolic blood pressure (DBP) was 97.24 ± 15.33 mmHg, while in the benign group, SBP was 134.55 ± 17.53 mmHg, and DBP was 88.18 ± 14.01 mmHg. In the malignant group in those who had undergone nephrectomies, the mean systolic pressure was 136.82, and the diastolic pressure was 85.90. In the benign group, the systolic and diastolic blood pressures were normal before and after surgery. Conclusion  In the group of patients with both renal cell carcinoma and arterial hypertension, their hypertension was resolved after they underwent nephrectomies. In conclusion, our data suggest that renal cell carcinomas may cause arterial hypertension.     

Acute stunning effect of hemodialysis on myocardial performance: A three-dimensional speckle tracking echocardiographic study

The effects of acute changes during hemodialysis (HD) on the myocardium are not yet known. The invention of three-dimensional speckle tracking echocardiography (3DSTE) has offered clinicians a new method to assess the movements of ventricular segments simultaneously in three spatial directions. The aim of this study was to evaluate the effect of first weekly standard HD process on the left ventricle (LV) and right ventricle (RV) global and regional myocardial function in patients with normal left ventricle ejection fraction using 3DSTE-derived indices. Patients (n=38) receiving maintenance HD in our clinic who have no known cardiovascular disease are examined just before and after a HD session using 3DSTE. Demographic and comorbidity data, renal replacement treatment characteristics, and laboratory test results are recorded. 3DSTE analysis is performed to calculate the LV global longitudinal, circumferential area and radial peak systolic strain, as well as RV septum and free-wall longitudinal strain and fractional area change. Patients are aged 52.8 ± 13.6 years and 52.6% of them are male. Mean dialysis duration is 56 months. The LV strain values of the patients changed markedly before and after HD (GLS: −14.2 ± 5.2, −11.1 ± 4.6 [P < .001], GCS: −14.8 ± 4.2, −12.4 ± 5.28 [P < .009]; GRS: 41.5 ± 16, 33.3 ± 16.5 [P = .003]; AREA −24.7 ± 7.2, −20.1 ± 7.6 [P = .001], respectively). We could not demonstrate any improvement in RV strain values before or after HD. LV strain values are positively correlated with blood pressure variability during the dialysis sessions. LV function is preserved better after HD in patients on beta or calcium channel blocker therapy compared to those who do not use these agents (P < .001, P < .01, respectively). HD treatment results in deterioration in all LV strain directions but not in RV. Strain assessment may improve vascular risk stratification of patients on chronic HD.     

Percutaneous transluminal angioplasty alone versus stent placement for the treatment of transplant renal artery stenosis

PurposeThe purposes of this retrospective study were to assess the efficacy of endovascular techniques for the treatment of transplant renal artery stenosis (TRAS) by analyzing technical and clinical success and to compare the results of percutaneous transluminal angioplasty (PTA) alone to those of stenting.Materials and methodsA retrospective analysis was conducted on 31 patients who underwent endovascular treatment for TRAS between January 2012 and December 2017. There were 23 men and 8 women with a mean age of 60.5 ± 14 (SD) years (range: 24–81 years). Ten patients (10/31; 32%; 8 men, 2 women; median age, 63 years) were treated with PTA alone and 21/31 (68%; 15 men, 6 women; median age, 65 years) with metallic stent placement. Several variables including serum creatinine level, glomerular filtration rate, arterial blood pressure value, antihypertensive medication obtained before and after treatment were compared. Technical success was assessed for each procedure. Clinical success was defined as a 15% drop in serum creatinine level, a decrease greater than 15% in mean blood pressure values or a decrease greater than 10% in mean blood pressure values with a reduction in the number of antihypertensive drugs needed for hypertension control.ResultsTechnical success was obtained in all patients [31/31; 100%; 95% confidence interval (CI): 89–100%] and clinical success in 27/31 patients (87%; 95%CI: 71–95%). Four patients (4/31; 13%; 95%CI: 5–29%) underwent repeat endovascular intervention. Mean serum creatinine level and mean arterial blood pressure values were significantly lower after treatment (177.4 and 93.8 μmol/l, respectively) compared to before treatment (319.4 and 106.7 μmol/l, respectively) in the stent group but not in the group treated with PTA alone (P = 0.0012 and P = 0.002, respectively).ConclusionThe endovascular approach is safe and effective in the management of TRAS and stenting, depending on the morphology of the stenosis, should be the treatment of choice when possible.     

Differential effects of ketamine and midazolam on heart rate variability

Alterations in autonomic activity caused by anaesthesia can be assessed by spectral analysis of heart rate variability (HRV). This study examined the effects of ketamine and midazolam on HRV. Thirty patients of ASA PS 1 were studied. Fifteen were given ketamine (2 mg · kg^?1) and 15 received midazolam (0.3 mg · kg^?1), m The RR intervals of ECG were measured before and after induction of anaesthesia for ten minutes during spontaneous respiration. Power spectral density of the data was computed using fast Fourier transform. The spectral peaks within each measurement were calculated: low frequency area (LF, 0.04–0.15 Hz), high frequency area (HF, 0.15–0.5 Hz), and total power (TP, 0.04–0.5 Hz). Normalized unit power was derived as follows: low frequency area (nuLF): LF/ TP × 100%, high frequency area (nuHF): HF/TP × 100%. Both ketamine and midazolam caused reductions in all measurements of HRV power (P < 0.05). However, ketamine increased nuLF from 64 ± 14% to 75 ± 13% (P < 0.05) and decreased nuHF from 36 ± 14% to 25 ± 13% (P < 0.05), while midazolam decreased nuLF from 66 ± 15% to 54 ± 14% (P < 0.05) and increased nuHF from 34 ± 15% to 46 ± 14% (P < 0.05). These results documented that both ketamine and midazolam reduced the total power and all frequency components of power in spite of their opposing effects on autonomic nervous activity. However, normalized unit power showed the expected sympathetic activation with ketamine and sympathetic depression with midazolam since ketamine increased nuLFand midazolam decreased nuLF.     

Effets hémodynamiques comparés du midazolam et du flunitrazépam chez les traumatisés crâniens en ventilation contrôlée

The haemodynamic effects of midazolam were compared with those of flunitrazepam in 10 patients with severe head injury under controlled ventilation. Right atrial pressure, pulmonary pressure, pulmonary capillary wedge pressure and cardiac output were measured using a Swan-Ganz thermodilution catheter. Arterial pressure (P?a) was recorded by radial arterial canulation. All patients in this cross-over study received midazolam (0.15 mg · kg^?1) and flunitrazepam (0.02 mg · kg^?1) intravenously randomly, with 24 h between the two injections. The measurements were first carried out before and then 5, 10, 20, 30 and 60 min after injection. The only significant variations after midazolam and flunitrazepam were a fall in P?a (from 93±12 to 81±11 mmHg for midazolam and from 89±14 to 78±20 mmHg for flunitrazepam) and in cardiac index (from 4.80±1.03 to 4.17±1.14 l · min^?1 · m^?2 for midazolam and from 5.18±1.32 to 4.54±1.03 l · min^?1 · m^?2 for flunitrazepam). The small decrease in heart rate was not significant. The cardiovascular changes after midazolam and flunitrazepam were small and similar for both drugs. It seemed that midazolam and flunitrazepam were safe for sedating head injured patients under controlled ventilation.     

Mild Renal Artery Stenosis Can Induce Renovascular Hypertension and is Associated with Elevated Renal Vein Renin Secretion

Renovascular hypertension is a syndrome which encompasses the physiological response of the kidney to changes in renal blood flow and renal perfusion pressure. Such physiological changes can occur with renal artery occlusion irrespective of the severity of the lesion. We have analyzed hypertensive patients with mild renal artery stenosis and compared them to patients with no stenosis. Renal vein renin sampling from catheterization of the renal vein was performed in all these patients. Patients with mild stenosis had higher renal vein renin ratio (3.01 ± 1.5) than the patients with no stenosis (1.10 ± 0.29; p = 0.002). Patients with mild stenosis were also found to have higher diastolic blood pressure and renal artery resistive indices when compared to patients with no stenosis. We therefore conclude that mild stenosis can precipitate renin‐mediated hypertension in renovascular stenosis and also emphasis that parameters pertinent to renal physiology need to be evaluated before considering treatment options in patients with renal artery stenosis and medical management with RAAS blockade is the preferred modality of therapy for patients with renin‐mediated hypertension.     

The influence of ureteral stent on renal pelvic pressure in vivo

The objective of this study was to explore the influence of ureteral stent on renal pelvic pressure by urodynamic study. 41 patients (with unilateral renal and/or ureteral calculi) after minimally invasive percutaneous nephrolithotomy (MPCNL) were placed a 4.7-Fr ureteral stent and 16-Fr nephrostomy tube. Renal pelvic pressure of these patients was measured by urodynamic study at the 5–7 days after MPCNL. Renal pelvic pressure (RPP), intraabdominal pressure (IAP), and vesical pressure (VP) during the filling and voiding phases were detected by urodynamic study with intravesical perfusion. At the baseline, intraabdominal pressure (IAP₀) was 27.52 ± 7.03 cmH₂O, renal pelvic pressure (RPP₀) was 33.07 ± 7.04 cmH₂O; at the maximum cystometric bladder capacity (MCBC) during the filling phase, vesical pressure (VP_vol) was 41.61 ± 10.34 cmH₂O, renal pelvic pressure (RPP_vol) was 39.44 ± 7.33 cmH₂O; at the maximum vesical pressure during the voiding phase, vesical pressure (VP_max) was 74.95 ± 12.79 cmH₂O, renal pelvic pressure (RPP_max) was 65.68 ± 17.03 cmH₂O. (1) There was a strong relationship between RPP₀ and IAP₀ (P = 0.0001); (2) There was statistical significance among RPP₀, RPP_vol and RPP_max (P = 0.0001); (3) RPP was higher than 40 cmH₂O during the voiding phase, and it was obviously relevant to the VP (P = 0.0001) but not to the MCBC (P = 0.2696). RPP increased mildly during the filling phase and dramatically during the voiding phase after stenting. RPP increased higher than the level required for a backflow (40 cmH₂O) during the voiding phase. So it was encouraged to remove the stent at earlier stage or decrease using the ureteral stent if possible.     

The use of phenylephrine to obtund oxytocin-induced hypotension and tachycardia during caesarean section

BackgroundOxytocin causes clinically significant hypotension and tachycardia. This study examined whether prior administration of phenylephrine obtunds these unwanted haemodynamic effects.MethodsForty pregnant women undergoing elective caesarean section under spinal anaesthesia were randomised to receive either an intravenous 50 μg bolus of phenylephrine (Group P) or saline (Group S) immediately before oxytocin (3 U over 15 s). Systolic blood pressure, diastolic blood pressure, mean arterial pressure and heart rate were recorded using a continuous non-invasive arterial pressure device. Baseline values were averaged for 20 s post-delivery. Between-group comparisons were made of the mean peak changes in blood pressure and heart rate, and the mean percentage changes from baseline, during the 150 s after oxytocin administration.ResultsThe mean ± SD peak percentage change in systolic blood pressure was −16.9 ± 2% in Group P, and −19.0 ± 1.9% in Group S and the estimated mean difference was 2.1% (95% CI −3.5% to 7.8%; P=0.44); corresponding changes in heart rate were 13.5 ± 2.3% and 14.0 ± 1.5% and the mean estimated difference was 0.5% (95% CI −6.0% to 5%; P=0.87). The mean percentage change from the baseline measurements during the 150 s period of measurement was greater for Group S than Group P: systolic blood pressure −5.9% vs −3.4% (P=0.149); diastolic blood pressure −7.2% vs −1.5% (P=0.014); mean arterial pressure −6.8% vs −1.5% (P=0.007); heart rate 2.1% vs −2.4% (P=0.033).ConclusionIntravenous phenylephrine 50 μg immediately before 3 U oxytocin during elective caesarean section does not prevent maternal hypotension and tachycardia.     

Low‐pressure pneumoperitoneum during laparoscopic donor nephrectomy to optimize live donors’ comfort

Nowadays, laparoscopic donor nephrectomy (LDN) has become the gold standard to procure live donor kidneys. As the relationship between donor and recipient loosens, it becomes of even greater importance to optimize safety and comfort of the surgical procedure. Low‐pressure pneumoperitoneum has been shown to reduce pain scores after laparoscopic cholecystectomy. Live kidney donors may also benefit from the use of low pressure during LDN. To evaluate feasibility and efficacy to reduce post‐operative pain, we performed a randomized blinded study. Twenty donors were randomly assigned to standard (14 mmHg) or low (7 mmHg) pressure during LDN. One conversion from low to standard pressure was indicated by protocol due to lack of progression. Intention‐to‐treat analysis showed that low pressure resulted in a significantly longer skin‐to‐skin time (149 ± 86 vs. 111 ± 19 min), higher urine output during pneumoperitoneum (23 ± 35 vs. 11 ± 20 mL/h), lower cumulative overall pain score after 72 h (9.4 ± 3.2 vs. 13.5 ± 4.5), lower deep intra‐abdominal pain score (11 ± 3.3 vs. 7.5 ± 3.1), and a lower cumulative overall referred pain score (1.8 ± 1.9 vs. 4.2 ± 3). Donor serum creatinine levels, complications, and quality of life dimensions were not significantly different. Our data show that low‐pressure pneumoperitoneum during LDN is feasible and may contribute to increase live donors’ comfort during the early post‐operative phase.     

Patient versus anesthesiologist controlled analgesia in cirrhotic patients undergoing percutaneous radiofrequency ablation of hepatic tumors

Background and aimsPatients may experience pain during Radiofrequency thermal ablation (RFTA) of hepatic tumors. The aim was to compare the use of fentanyl administered through the patient controlled analgesia (PCA) machine with the same drug given intermittently by the anesthesiologist.MethodsIn this prospective, randomized, double-blind study, eighty cirrhotic patients underwent RFTA of hepatic tumors were enrolled. All patient received midazolam 10 μg/kg and fentanyl 1 μg/kg IV, then 5–10 mL of 2% lidocaine were injected from the skin to the liver capsule along a specified insertion route, then the RFTA electrode was advanced into the tumor. For maintenance of analgesia bolus doses of fentanyl were then administered either by patient himself (PCA group, n = 40) with each bolus dose contained 10 μg of fentanyl with a 1 min lock-out time or by the anesthesiologist (ACA group, n = 40).ResultsPCA group received significantly higher doses of fentanyl with a mean value of 53.5 ± 13.5 μg/session, while it was 36.7 ± 13.4 μg/session in the ACA group. Patient satisfaction rates were higher in the PCA than ACA with mean values of 8.32 ± 0.62 and 7.85 ± 0.73, respectively. The mean pain score was statistically lower in the PCA group than the ACA group with mean value 3.37 ± 0.70 and 3.97 ± 0.89, respectively. There was significant difference in the mean values of the demand/ delivered ratio between groups to be 1.47 ± 0.28 and 2.50 ± 0.73 in PCA and ACA groups, respectively.ConclusionPCA with fentanyl proved to be a better alternative than ACA in terms of patient comfort and satisfaction.     

Optimal fentanyl dosage for attenuating systemic hemodynamic changes, hormone release and cardiac output changes during the induction of anesthesia in patients with and without hypertension: a prospective, randomized, double-blinded study

Purpose

The purpose of this study was to compare the dose-related effects of fentanyl on systemic hemodynamics, hormone release and cardiac output in response to endotracheal intubation in patients with and without hypertension.

Methods

Forty-five patients without hypertension and 45 patients with hypertension (total 90 patients) undergoing elective general surgical, urological or gynecological procedures under general anesthesia were studied. The patients were randomly divided into three groups to receive either saline (control), 2.0 μg/kg fentanyl or 4.0 μg/kg fentanyl before tracheal intubation. Anesthesia was induced via intravenous target controlled infusion of propofol (plasma concentration, 4.0 μg/mL) followed by administration of the three drugs. Heart rate, blood pressure, and cardiac output were continuously monitored using Flo Trac/Vigileo system? and Bispectral index from before anesthetic induction until 10 min after tracheal intubation.

Results

In patients without hypertension, there was a significant difference in mean arterial pressure (MAP) among the three groups 2 min after intubation. Cardiac index (CI) in all three groups decreased before intubation compared with that in the awake period, returning to awake values after intubation in all three groups. There was a significant difference in CI between the 4 μg/kg fentanyl group and the other two groups immediately and 1 min after intubation. In patients with hypertension, a differential time course of MAP changes was observed among the three groups after intubation. CI in the three groups decreased after the induction of anesthesia and increased after intubation in control and 2 μg/kg fentanyl groups compared with that in the awake period.

Conclusions

The present study shows that it is preferable to administer 2 μg/kg fentanyl in patients without hypertension and 4 μg/kg fentanyl in patients with hypertension in order to minimize the changes in heart rate, systolic blood pressure and cardiac output associated with tracheal intubation.     

Conventional or minimized cardiopulmonary bypass support during coronary artery bypass grafting? – An analysis by means of perfusion and body mass index

The use of minimized cardiopulmonary bypass support to reduce the side effects of extracorporeal circulation is still contradictorily discussed. This study compares perfusion operated by conventional (CCPB) and minimized (MCPB) cardiopulmonary bypass support during coronary artery bypass grafting (CABG). This study includes the data of 5164 patients treated at our department between 2004 and 2014. Tissue perfusion during cardiopulmonary bypass support and cardiac arrest was assessed by means of body mass index, hemodilution, blood pressure with corresponding pump flow and venous oxygen saturation, serum lactate, and serum pH. Hemodilution was more pronounced after CCPB: hemoglobin had dropped to 4.47 ± 0.142 g/dL after CCPB and to 2.77 ± 0.148 g/dL after MCPB (P = 0.0022). Despite the higher pump flow in conventional circuits (4.86–4.95 L/min vs. 4.1–4.18 L/min), mean blood pressure was higher during minimized bypass support (53 ± 10 vs. 56 ± 13 mm Hg [aortic clamping], 57 ± 9 vs. 61 ± 12 mm Hg [34°C], 55 ± 9 vs.59 ± 11 mm Hg [aortic clamp removal], P < 0.0001) at all time points. Venous oxygen saturation remained on comparable levels of >70% during both conventional and minimized cardiopulmonary bypass support. The increase in serum lactate was more pronounced after CCPB (8.98 ± 1.28 vs. 3.66 ± 1.25 mg/dL, P = 0.0079), corresponding to a decrease in serum pH to acidotic levels (7.33 ± 0.06 vs. 7.35 ± 0.06, P < 0.0001). These effects were evident in all BMI ranges. Minimized cardiopulmonary bypass support provides efficient perfusion in all BMI ranges and is thus equivalent to conventional circuits.     

Haemodynamic,electrolyte and metabolic changes during percutaneous nephrolithotomy

Objectives The objectives were to evaluate haemodynamic, electrolyte and metabolic changes in patients undergoing percutaneous nephrolithotomy when normal saline was used for irrigation; and to correlate these changes with irrigation time, volume of irrigation fluid absorbed and number of percutaneous interventions. Methods Twenty adults undergoing percutaneous nephrolithotomy were studied. Heart rate, systolic and diastolic blood pressure, arterial blood gases, electrolytes and temperature were monitored before, during and after irrigation. Haemoglobin, urea and creatinine values were recorded before and 24 h after the procedure. Durations of anaesthesia and irrigation; volumes of irrigation fluid used and effluent fluid; and number of percutaneous interventions during the procedure were also recorded. Results No significant changes occurred in mean heart rate, systolic and diastolic blood pressure, electrolytes, haemoglobin, urea and creatinine. There was a significant fall in mean pH in post-operative period (P = 0.003) and bicarbonate values showed a negative correlation with duration of irrigation. Number of percutaneous interventions had positive correlations with duration of irrigation and volume of irrigant fluid absorbed. Conclusions No significant changes occurred in haemodynamics and electrolytes, but there was a trend towards metabolic acidosis. Arterial blood gases should be monitored during and after PCNL in cases with prolonged irrigation time, repeated percutaneous interventions and patients having compromised renal function and metabolic status.