First Hour Of Surgery Research Articles

Effect of the prone position on mechanical power in elective surgical patients under general anesthesia: A prospective observational study.

To evaluate how the prone position influences mechanical power (MP) during elective surgical procedures. In this prospective study carried out at Karadeniz Ereğli Government Hospital, Zonguldak, Turkey, from January 2024 to February 2024, 76 patients under general anesthesia were evaluated at different time points during the surgical procedure. Hemodynamic, laboratory, and mechanical ventilation data were also recorded. The MP increased in the prone position at the beginning of surgery. Transitioning to the supine position at the end of surgery led to a decrease in MP. At the end of surgery, the mean MP in supine and prone positions was found to be higher compared to those measured in the first hour of surgery. Mechanical power and body mass index (BMI) exhibited a significant positive correlation. Position changes influence MP. Returning to the prone position increases MP. An increase in BMI is associated with an increase in MP.ANZCTR Reg. No.: ACTRN12623001281684.

#3065 Factors associated with recurrence or persistently high parathormone levels after parathyroidectomy in patients with CKD

Abstract Factors associated with recurrence or persistently high parathormone levels after parathyroidectomy in patients with secondary hyperparathyroidism receiving renal replacement therapy Background and Aims Resistant hyperparathyroidism that indicates surgery usually occurs in patients with CKD who receive renal replacement therapy (RRT). This study aims to evaluate the factors associated with persistent or recurrent high levels of PTH after parathyroidectomy due to SHPT in patients receiving RRT. Method In this retrospective study, we included 66 adult patients (mean age: 46.86 ± 13.79) with parathyroidectomy for SHPT receiving renal replacement therapy. Clinicopathological features, laboratory parameters (preoperatively, at the first hour of surgery, at least every three months for at least two years after surgery), type of surgery and pathologic diagnosis were recorded from the medical records. Persistence was defined as failure to achieve a decrease in PTH level of more than fifty percent of preoperative PTH level. Recurrence was defined as elevated PTH levels after six months post-operation (>600 pg/mL). Results The demographics and clinical characteristics of the study population are described in Table 1. High PTH levels were observed in nineteen patients, while recurrence was observed in nine. Persistence was associated with lower preoperative ALP levels (455.27 ± 296.23, 619.72 ± 593.18, p = 0.017). Recurrence was associated with higher preoperative CRP levels (22.89 ± 6.82, 6.82 ± 5.35, p:0,046) and postoperative high phosphorus levels (4.93 ± 0.99, 4.16 ± 1.09, p = .049). Conclusion In our study persistence of high parathormone levels were more common in patients with lower preoperative ALP levels and recurrence was associated with higher preoperative CRP levels and postoperative inadequate phosphorus control. In conclusion, patients with lower ALP and higher CRP levels can be suitable for total parathyroidectomy, which is associated with a lower recurrence rate in SHPT. Also, postoperative phosphorus control can be a key point for preventing the patients' recurrence of high PTH level.

Intra-Operative Hypotension is an Important Modifiable Risk Factor for Major Complications in Spinal Fusion Surgery.

Retrospective observational cohort. This study explores the impact of Intraoperative hypotension (IOH)on post-op complications for major thoracolumbar spine fusion procedures. IOH with mean arterial pressure (MAP) < 65mmHg is associated with post-op acute kidney injury (AKI) in general surgery. In spinal deformity surgery, IOH is a contributing factor to MEP changes and spinal cord dysfunction with deformity correction. 539 thoracolumbar fusion cases, > 6 surgical levels and > 3 hours duration were identified. Anesthetic/surgical data included OR time, fluid volume, blood loss, blood product replacement and use of vasopressors. Arterial-line based MAP data was collected at 1 min intervals. Cummulative duration of MAP < 65mmHg was recorded. IOH within the first hour of surgery vs. the entire case was determined. Post-op course and complications including SSI, GI complications, pulmonary complications, MI, DVT, PE, AKI and encephalopathy were noted. Cumulative complications were grouped as none, 1-2 complications, or >3 complications. There was a significant association between occurrence of complications and duration of IOH within the first hour of surgery (8.2 vs. 5.6 min, P<0.001) and across the entire procedure (28.1 vs. 19.3 min, P=0.008). This association persisted for individual major complications including SSI, acute respiratory failure, PE, ileus requiring NGT and post-operative cognitive dysfunction. Comparison of patients with 0 vs. 1-2 vs. 3 or more complications demonstrated that patients with 3 or more complications had a longer duration of IOH in the first hour of the surgery and that patients who had no complications received less vasopressor than patients who had 1-2 or 3 or more complications. This study identifies duration of IOH during the first hour of surgery as a previously unrecognized modifiable risk associated with major complications for multi-level lumbar fusion surgery.

Digital thermography complements Laser Speckle Contrast Imaging for the diagnosis of quantified severe mesenteric traction syndrome — A prospective cohort study

IntroductionThe diagnosis of severe mesenteric traction syndrome (MTS) is based on assessing the developed degree of facial flushing. Only one validated objective diagnostic method, Laser Speckle Contrast Imaging (LSCI), exists. However, this method is sensitive to distance, motion, and angulation. Digital thermography is known to correlate well with LSCI without the same limitations, but has never been tested in relation to MTS. This study aimed to examine the thermographic changes during the development of severe MTS and to calculate a cut-off value for identifying severe MTS. MethodsA prospective cohort study was performed on patients planned for open esophagectomy and pancreatic surgery from March 2021 to April 2022. All patients underwent continuous measurement on their forehead using LSCI and digital thermography during the first hour of surgery. The validated LSCI cut-off value was used to grade the severity of MTS. Blood samples and hemodynamics were collected at predefined time points. ResultsFifty-seven patients were included. Patients developing severe MTS had increased facial skin temperature 15 min (p = 0.002) and 30 min into surgery (p < 0.001). A cut-off value for identifying severe MTS using thermography was identified (35.55 °C, p < 0.001). Patients identified as developing severe MTS using this cut-off value had a higher level of prostacyclin (p = 0.001) and lower systemic vascular resistance (p < 0.001) 15 min into surgery, as compared with patients not developing severe MTS. ConclusionThis study shows that digital thermography may complement LSCI in the objective identification of severe MTS.

Analgesic and hemodynamic effects of intravenous magnesium sulfate infusion versus lidocaine infusion in patients undergoing thyroid surgery for toxic goiter resection: a randomized controlled study

Background Anesthesia for toxic goiter resection is challenging as manipulation of the thyroid gland and inadequate postoperative pain control could lead to hemodynamic instability due to stress and a neurohormonal response. Both magnesium sulfate and lidocaine are known for their analgesic effects and decreasing stress response. Herein, we compared the previous two medications regarding intraoperative hemodynamics and postoperative analgesia. Patients and methods 57 patients who underwent toxic goiter resection were enrolled in this prospective randomized trial (group M received magnesium sulfate, group L received lidocaine, and group C received normal saline). Intraoperative hemodynamics and postoperative analgesic profiles were assessed. Results Both injection groups expressed significantly lower pain scores compared with control group at Post anaesthesia care unit (PACU) and one-hour postoperative. Postoperative fentanyl consumption was significantly lower, and the time to first analgesic request was significantly prolonged in Magnesium and Lidocaine groups than in the control group. The previous beneficial effects were more prominent in the Magnesium Group compared with the Lidocaine Group. There was no significant difference in mean arterial pressure (MAP) and heart rate (HR) among the three study groups at the baseline, after the end of infusion, and after induction. Nonetheless, there was a significant rise in mean arterial pressure and heart rate values in the control group compared with the Magnesium and Lidocaine Groups with intubation and during the first hour of surgery. Conclusion Both magnesium sulfate and lidocaine have beneficial hemodynamic stabilizing and analgesic effects in patients undergoing thyroid surgery for toxic goiter, with a slight superiority for magnesium.

EEG pre-burst suppression: characterization and inverse association with preoperative cognitive function in older adults.

The most common complication in older surgical patients is postoperative delirium (POD). POD is associated with preoperative cognitive impairment and longer durations of intraoperative burst suppression (BSup) - electroencephalography (EEG) with repeated periods of suppression (very low-voltage brain activity). However, BSup has modest sensitivity for predicting POD. We hypothesized that a brain state of lowered EEG power immediately precedes BSup, which we have termed "pre-burst suppression" (preBSup). Further, we hypothesized that even patients without BSup experience these preBSup transient reductions in EEG power, and that preBSup (like BSup) would be associated with preoperative cognitive function and delirium risk. Data included 83 32-channel intraoperative EEG recordings of the first hour of surgery from 2 prospective cohort studies of patients ≥age 60 scheduled for ≥2-h non-cardiac, non-neurologic surgery under general anesthesia (maintained with a potent inhaled anesthetic or a propofol infusion). Among patients with BSup, we defined preBSup as the difference in 3-35 Hz power (dB) during the 1-s preceding BSup relative to the average 3-35 Hz power of their intraoperative EEG recording. We then recorded the percentage of time that each patient spent in preBSup, including those without BSup. Next, we characterized the association between percentage of time in preBSup and (1) percentage of time in BSup, (2) preoperative cognitive function, and (3) POD incidence. The percentage of time in preBSup and BSup were correlated (Spearman's ρ [95% CI]: 0.52 [0.34, 0.66], p < 0.001). The percentage of time in BSup, preBSup, or their combination were each inversely associated with preoperative cognitive function (β [95% CI]: -0.10 [-0.19, -0.01], p = 0.024; -0.04 [-0.06, -0.01], p = 0.009; -0.04 [-0.06, -0.01], p = 0.003, respectively). Consistent with prior literature, BSup was significantly associated with POD (odds ratio [95% CI]: 1.34 [1.01, 1.78], p = 0.043), though this association did not hold for preBSup (odds ratio [95% CI]: 1.04 [0.95, 1.14], p = 0.421). While all patients had ≥1 preBSup instance, only 20.5% of patients had ≥1 BSup instance. These exploratory findings suggest that future studies are warranted to further study the extent to which preBSup, even in the absence of BSup, can identify patients with impaired preoperative cognition and/or POD risk.

Laser Speckle Contrast Imaging-based diagnosis of severe mesenteric traction syndrome: Hemodynamics and prostacyclin - A prospective cohort study.

Today, the diagnosis and grading of mesenteric traction syndrome relies on a subjective assessment of facial flushing. However, this method has several limitations. In this study, Laser Speckle Contrast Imaging and a predefined cut-off value are assessed and validated for the objective identification of severe mesenteric traction syndrome. Severe mesenteric traction syndrome (MTS) is associated with increased postoperative morbidity. The diagnosis is based on an assessment of the developed facial flushing. Today this is performed subjectively, as no objective method exists. One possible objective method is Laser Speckle Contrast Imaging (LSCI), which has been used to show significantly higher facial skin blood flow in patients developing severe MTS. Using these data, a cut-off value has been identified. This study aimed to validate our predefined LSCI cut-off value for identifying severe MTS. A prospective cohort study was performed on patients planned for open esophagectomy or pancreatic surgery from March 2021 to April 2022. All patients underwent continuous measurement of forehead skin blood flow using LSCI during the first hour of surgery. Using the predefined cut-off value, the severity of MTS was graded. In addition, blood samples for prostacyclin (PGI2) analysis and hemodynamics were collected at predefined time points to validate the cut-off value. Sixty patients were included in the study. Using our predefined LSCI cut-off value, 21 (35%) patients were identified as developing severe MTS. These patients were found to have higher concentrations of 6-Keto-PGFaα (p=0.002), lower SVR (p<0.001), lower MAP (p=0.004), and higher CO (p<0.001) 15min into surgery, as compared with patients not developing severe MTS. This study validated our LSCI cut-off value for the objective identification of severe MTS patients as this group developed increased concentrations of PGI2 and more pronounced hemodynamic alterations compared with patients not developing severe MTS.

The Effectiveness of Intraoperative Ketamine and Fentanyl as Preemptive Analgesia Assessed with qNOX Score

Background: Inadequate management of intraoperative pain poses a risk of postoperative chronic pain complications. The use of preemptive analgesia before the onset of surgical incision stimulation was considered to prevent central sensitization. Clinical research around the terms of preemptive analgesia needs to be proven by nociception-based intraoperative monitoring. An objective modality with EEG guidance can provide information on noxious stimuli.Objective: To determine the effectiveness of ketamine and fentanyl administration as preemptive analgesia measured by qNOX scores through the CONOX tool.Methods: This study is a single-blinded randomized experiment with the division of two groups: control and treatment. The control group received preemptive fentanyl, and the treatment group received preemptive ketamine and fentanyl. Then the qNOX score was assessed during operation.Result: The qNOX score of the treatment group in minute-15 and 30 was lower than the control group (p = 0.007; p = 0.025), while in the minute-90 it was higher than the control group (p = 0.001). The mean first 1-hour qNOX score was lower in the treatment group (p &lt;0.001), while in the second 1-hour was higher in the treatment group (p = 0.003). The mean total dose of fentanyl supplementation in the treatment group was lower than in the control group (71.3 ± 25.1 grams vs. 92.0 ± 28.3 grams; p = 0.044).Conclusion: The administration of combined ketamine and fentanyl as preemptive analgesia is more effective in the first hour of surgery compared to single preemptive fentanyl measured by qNOX score. Preemptive ketamine and fentanyl decrease the total dose of intraoperative fentanyl supplementation compared with single-dose preemptive fentanyl administration.

English

BACKGROUND Managing pain and stress during and after any surgical procedure is a real challenge and a matter of concern for both surgeons and anaesthesiologists. Various analgesics like tramadol and nalbuphine have been used as adjuncts to anaesthetic agents with different efficacy. We wanted to do a comparative assessment of efficacy between intravenous (IV) administration of tramadol and nalbuphine in managing perioperative pain and stress. METHODS This was a single blinded randomised control trial, which included 60 female adult patients in the age group of 30 - 50 years who were posted for surgical procedures like elective vaginal hysterectomy under spinal block. Patients with comorbidities like diabetes, obesity, hypertension, impaired pulmonary function, recent history of medication with selective serotonin reuptake inhibitors were excluded from the study. Study participants were divided into two groups - group tramadol (TR) and group nalbuphine (NA) with 30 patients in each group. Group TR was given tramadol 0.5 - 0.7 mg / Kg whereas group NA was given nalbuphine 0.1 - 0.2 mg / Kg after an hour of spinal block. Both drugs were administered intravenously. Midazolam 0.01 - 0.05 mg / Kg was administered intravenously within first hour of surgery for sedation. Pain, stress and sedation score, requirement of rescue analgesics and occurrence of adverse drug reactions (ADRs) over 12 hours postoperatively were compared. RESULTS Significant lowering of pain and stress scores and higher sedation score was observed in group NA in comparison to group TR. The requirement of rescue analgesic and occurrence of side effects like nausea and vomiting were less in group NA. CONCLUSIONS Intravenous administration of nalbuphine was found to be more effective in perioperative control of pain and stress and can be a better choice than intravenous tramadol. KEYWORDS Efficacy, Tramadol, Nalbuphine, Rescue Analgesia

Management of massive blood loss in a dog under general anaesthesia during a sternotomy

A 2-year-old male neutered American Staffordshire Terrier was presented collapsed, with tachycardia, dyspnoea and pale mucous membranes. An emergency sternotomy and lateral thoracotomy was performed. Before surgery the dog's blood was typed and found to be DEA negative. The dog lost the equivalent of its entire blood volume (estimated) during the first hour of surgery. Cardiovascular parameters initially responded to boluses of crystalloids and colloids. He also received transfusions of DEA negative packed red blood cells and fresh frozen plasma. Due to ongoing haemorrhage, the dog's clinical condition, and a lack of availability of any more DEA negative blood products, the decision was made to give a unit of DEA positive packed red blood cells. The dog recovered uneventfully, although following diagnosis of an aggressive soft tissue sarcoma the dog was later euthanased. This report discusses the management of massive blood loss in veterinary medicine and the implications, potential options for management, and treatment of these cases perioperatively.

Administration of HES in elderly patients undergoing hip arthroplasty under spinal anesthesia is not associated with an increase in renal injury

BackgroundHydroxyethyl starch (HES) is applied to achieve volume expansion during surgery; however, nephrotoxicity may be induced in patients with sepsis. Simultaneously, neutrophil gelatinase-associated lipocalin (NGAL) and IL-18 have been illustrated as pivotal indicators to diagnose the acute kidney injury (AKI) early. This multi-center, randomized, double-blinded, placebo-controlled study aimed to investigate whether 6% HES 130/0.4 administration caused postoperative AKI, which can be revealed by urinary and plasma NGAL and IL-18 estimations in elderly patients with normal renal function undergoing hip arthroplasty under spinal anesthesia.Methods120 ASA I–III, patients aged >65 y undergoing hip arthroplasty under spinal anesthesia randomly received 6% HES 130/0.4 or sodium lactate Ringer’s solution 7.5 mL/kg during the first hour of surgery. 118 patients completed the study. Blood pressure, NGAL concentrations, IL18, β2 micro-albumin and albumin in urine and creatinine, NGAL and IL-18 in plasma were repeatedly measured before, during, and after surgery.ResultsThe groups were balanced in mean arterial pressure, urine and plasma NGAL, plasma IL-18 and creatinine, urine β2 microalbumin and albumin (P > 0.05). Urine IL-18 was dramatically elevated in both groups after surgery (P < 0.05), but did not vary significantly between the groups (P > 0.05).ConclusionElderly patients undergoing surgery under spinal anesthesia are a high-risk population in AKI. These patients with normal renal function receiving a spinal anesthesia for a short duration surgery would not develop AKI when 500 mL (small volume) HES is infused.Trial registrationIdentifier: NCT02361736. Registration date was 2 February 2015.

Fluid Retention is Alleviated by Crystalloid but Not by Colloid Fluid after Induction of General Anesthesia: An Open-Labeled Clinical Trial

Background: Renal fluid conservation, which is possible to quantify by urine analysis, is often caused by dehydration. The present study aimed to determine whether such fluid retention could be reversed by crystalloid and/or colloid fluid during surgery. Methods: Urine colour, specific weight, osmolality and creatinine concentration were used to calculate a “fluid retention index” (FRI) in 108 patients undergoing major abdominal surgery. Urine was collected at baseline and after flow-guided fluid volume optimisation with hydroxyethyl starch 130/0.4 (n=86) or Ringer's lactate (n=22). The third sample was taken after one hour of surgery. Results: The mean preoperative FRI was 3.4 (SD 1.1) and did not change during the volume optimization. The FRI was unchanged from starch during the first hour of surgery, whereas it decreased from 3.6 to 2.9 in response to Ringer´s lactate (P<0.01). The urine became more concentrated when the urinary excretion was below 100 ml/hour. Preoperative fluid retention (FRI ≥ 4.0), which is cut-off for renal fluid conservation consistent with a body fluid deficit amounting to 3% of the body weight, was present in 32% of the patients. Such retention increased the risk of a minor postoperative increase in serum creatinine (n=15, odds ratio 6.4) despite a higher creatinine clearance during the surgery (155 versus 80 ml/min; P<0.02). Conclusions: Ringer´s lactate, but not hydroxyethyl starch, decreased the urinary markers of fluid retention in the perioperative setting. Fluid retention increased the risk of a postoperative increase in serum creatinine.

Lack of nephrotoxicity by 6% hydroxyethyl starch 130/0.4 during hip arthroplasty: a randomized controlled trial.

Hydroxyethyl starch (HES) is commonly used as plasma expander during surgery but may be nephrotoxic as seen in studies in patients with sepsis. The authors hypothesized that the possible nephrotoxicity of 6% HES 130/0.4 could be revealed by measurements of urinary excretion of neutrophil gelatinase-associated lipocalin (u-NGAL) in patients with normal renal function during hip arthroplasty. In this randomized, double-blinded, placebo-controlled study, 40 patients referred for hip arthroplasty received either 6% HES 130/0.4 or isotonic saline 0.9%; 7.5 ml/kg during the first hour of surgery and 5 ml/kg during the following hours; 38 patients completed the study. U-NGAL, urine albumin, blood pressure, and plasma concentrations of creatinine, renin, NGAL, albumin, angiotensin-II, and aldosterone were measured before, during, and after surgery. U-NGAL was defined as primary outcome. There were no significant differences in U-NGAL (mean difference and 95% CI), plasma creatinine, and urine albumin during the study. U-NGAL and urine albumin increased significantly in both groups the morning after surgery but was normalized at follow-up after 10 to 12 days. Mean arterial pressure was significantly higher during the recovery period in the HES group compared with that in the control group (91 [13] and 83 [6] mmHg, mean [SD], P < 0.03). Plasma renin and angiotensin-II were nonsignificantly different in both groups, whereas plasma aldosterone was significantly lower in the HES group. Plasma albumin was reduced in both groups, but to a significantly lower level in the HES group. The study showed no evidence of a harmful effect of intraoperative infusion of 6% HES 130/0.4 on renal function in patients during hip arthroplasty.

A proposed methodology to control body temperature in patients at risk of hypothermia by means of active rewarming systems.

Hypothermia is a common complication in patients undergoing surgery under general anesthesia. It has been noted that, during the first hour of surgery, the patient's internal temperature (T core) decreases by 0.5–1.5°C due to the vasodilatory effect of anesthetic gases, which affect the body's thermoregulatory system by inhibiting vasoconstriction. Thus a continuous check on patient temperature must be carried out. The currently most used methods to avoid hypothermia are based on passive systems (such as blankets reducing body heat loss) and on active ones (thermal blankets, electric or hot-water mattresses, forced hot air, warming lamps, etc.). Within a broader research upon the environmental conditions, pollution, heat stress, and hypothermia risk in operating theatres, the authors set up an experimental investigation by using a warming blanket chosen from several types on sale. Their aim was to identify times and ways the human body reacts to the heat flowing from the blanket and the blanket's effect on the average temperature T skin and, as a consequence, on T core temperature of the patient. The here proposed methodology could allow surgeons to fix in advance the thermal power to supply through a warming blanket for reaching, in a prescribed time, the desired body temperature starting from a given state of hypothermia.

An oxychlorine solution changes the time‐course of peritoneal cytokine production associated with surgical adhesion formation

The goal of the study was to determine the time‐course of peritoneal inflammatory (IL‐1 beta, IL‐6 and TNF‐alpha) and antiinflammatory (IL‐4 and IL‐10) cytokines in male Wistar rats (12–14 week‐old) subjected to an experimental model of surgical adhesions, with or without a peritoneal treatment with a proprietary anti‐adhesion oxychlorine solution (OS, 100 ppm). All the cytokines but IL‐1 beta increased significantly within the first hour of surgery returning to the basal concentration 11 hours later. IL‐1 beta had a delayed increase (12 h), which returned to basal concentrations 12 h later. OS significantly reduced the production of TNF‐alpha, IL‐1 beta, IL‐10 and IL‐6. The strongest effect was on IL‐10. IL‐4 increased with OS (first hour). The early production of IL‐6, TNF‐alpha, IL‐10 and IL‐4 indicates that macrophages 1 M1 (inflammatory) and M2 (repairing) are simultaneously activated from the beginning of the surgery and both probably play a role in adhesion formation. OS could be interfering with the early stimuli that activate M1 and M2 macrophages, which could explain its anti‐adhesion suppression effect (supported by grant SIP20121039).

Comparison of melatonin and oxytocin in the prevention of critical illness polyneuropathy in rats with experimentally induced sepsis

BackgroundCritical illness polyneuropathy is an acute neuromuscular disorder of critically ill patients and is characterized by limb and respiratory muscle weakness. The purpose of the study was to evaluate the neuroprotective effects of melatonin (MEL) and oxytocin (OT) on the early stage of sepsis by recording compound muscle action potentials and measuring plasma tumor necrosis factor (TNF)-α levels, lipid peroxidation (malondialdehyde; MDA), and total antioxidant capacity. Materials and methodsOne hundred adult male Sprague-Dawley rats were included in the study. The cecal ligation and puncture (CLP) procedure was performed to induce the sepsis model. MEL (10, 20, and 40 mg/kg), OT (0.4, 0.8, and 1.6 mg/kg), and a combination of MEL (20 mg/kg) and OT (0.8 mg/kg) were administered intraperitoneally in the first hour of surgery. Electromyography (EMG) studies were achieved 24 h after CLP surgery and then blood samples were collected for biochemical measurements. ResultsEMG findings revealed that compound muscle action potential amplitude was significantly decreased and distal latency was prolonged in the CLP group compared with the sham group (P < 0.05 and P < 0.0005). Moreover, the animals that received CLP surgery showed significantly higher TNF-α and MDA levels and lower total antioxidant capacity values than the sham group. The administration of MEL and OT to rats significantly abolished the EMG alterations and suppressed oxidative stress and TNF-α release in CLP-induced rats. ConclusionsThe inflammatory processes and imbalance in oxidative/antioxidative status play important roles in the pathogenesis of critical illness polyneuropathy. We suggest that both oxytocin and melatonin may have beneficial effects against sepsis-induced polyneuropathy in critical illness.

A Double-Blind Randomized Controlled Clinical Trial to Assess the Effect of Doppler Optimized Intraoperative Fluid Management on Outcome Following Radical Cystectomy

Cardiovascular optimization via esophageal Doppler can minimize gastrointestinal hypoperfusion, reducing the risk of multiple organ dysfunction and postoperative complications during major surgery. We assessed the effect of esophageal Doppler guided cardiovascular optimization in patients undergoing radical cystectomy. We conducted a prospective, randomized, double-blind controlled trial at a United Kingdom teaching hospital between 2006 and 2009. A total of 66 patients were randomized to a control arm (34) and an intervention arm (32). The control group received standard intraoperative fluids. The intervention group received (additional) Doppler guided fluid. Primary outcomes were markers of gastrointestinal morbidity such as ileus, flatus and bowel opening. Secondary outcomes were postoperative nausea and vomiting, wound infection and operative intravenous fluid volumes (total and hourly). There were significant reductions in the control and intervention arms in the incidence of ileus (18 vs 7, p <0.001), flatus (5.36 vs 3.55 days, p <0.01) and bowel opening (9.79 vs 6.53 days, p = 0.02), respectively. Nausea and vomiting were significantly reduced in the study group at 24 and 48 hours postoperatively (11 vs 3, p <0.01 and 13 vs 1, p <0.0001). Wound infection rates were significantly reduced (8 vs 1 superficial, p <0.01 and 10 vs 2 combined, p <0.01). Study patients received significantly higher volumes (ml/kg per minute) of intravenous fluid (0.19 vs 0.23, p <0.01) related to a significantly higher volume (ml/kg) in the first hour of surgery (14.1 vs 21.0, p = 0.0001). Cardiovascular optimization using esophageal Doppler significantly improved postoperative markers of gastrointestinal function.

Nitric oxide production in the sphenoidal sinus

Problem: Nitric oxide (NO) is considered to prevent local infections in paranasal sinus. As sphenoidal sinusitis is rare our hypothesis was that NO concentration is higher in spenoidal sinus than in maxillary sinus. The sphenoidal sinus is not easily accessible and NO concentration in this sinus has been reported in one patient. We studied the presence of NO and NO-synthesizing enzymes (NOS), in the maxillary and sphenoidal sinus. Methods: Ten patients (3 male; mean age, 55 years) undergoing surgery for pituitary adenomas were examined perioperatively. Patients were orally intubated and gas samples were taken during the first hour of surgery. By using chemiluminiscence technique the presence of NO gas in the maxillary and sphenoidal sinus was measured. Distribution of different NOS and NADPH-diaphorase in mucosal biopsies was also studied. Results: The individual concentration of NO was approximately half in the sphenoidal sinus compared to the maxillary sinus. Mean value of NO in the sphenoidal sinus was 2575 ppb and in the maxillary sinus 6792 ppb. Morphological analyses revealed presence of the isozymes: inducible NOS, neuronal NOS, and endothelial NOS, as well as NADPH-diaphorase, in the mucosa of the maxillary and sphenoidal sinus. Most abundant was inducible NOS. Conclusion: In this small study we found lower concentrations of NO in the sphenoidal sinus than the maxillary sinus. Significance: The concentration of NO, and the abundant presence of inducible NOS in the sphenoidal sinus in these nonallergic, noninfected patients will be discussed. Support: None reported.

Circulating leptin and the perioperative neuroendocrinological stress response after pediatric cardiac surgery

Leptin may be involved in the acute stress response, regulating inflammatory parameters of major importance after cardiopulmonary bypass (CPB) surgery. Critically ill patients demonstrated significant increases in leptin levels in response to stress-related cytokines (tumor necrosis factor, interleukin [IL]-1) and abolishment of the circadian rhythm of leptin secretion. We characterized the pattern of leptin secretion in the acute postoperative period in children undergoing cardiac surgery and compared the changes in leptin levels with concomitantly occurring changes in cortisol levels, IL-8, and clinical parameters. Investigative study. University-affiliated tertiary care hospital. Twenty-nine consecutive patients, aged 6 days to 15 yrs, operated upon for the correction of congenital heart defects were studied. Surgery in 20 patients (group 1) involved conventional CPB techniques, and 9 (group 2) underwent closed-heart surgery. The time courses of leptin, cortisol, and IL-8 levels were determined. Serial blood samples were collected preoperatively, on termination of CPB, and at six time points postoperatively. Plasma was recovered immediately, aliquoted, and frozen at -70 degrees C until use. The leptin levels in group 1 decreased during CPB to 51% of baseline (p <.001), then gradually increased, reaching 120% of baseline levels at 12-18 hrs postoperatively (p <.001), returning to baseline levels at 24 hrs (p <.01). In patients undergoing closed-heart surgery (group 2), leptin levels displayed a pattern resembling the first group: they decreased during surgery to 71% of baseline levels (p =.002) and showed a tendency to return to baseline thereafter. All group 1 patients' cortisol levels increased significantly during the first hour of surgery, then decreased, returning to baseline levels at 18-24 hrs postoperatively. There was a significant negative correlation between leptin and cortisol levels (r = -2.8, p <.01). In group 2, cortisol levels increased during and after surgery, peaking 4 hrs postoperatively and decreasing thereafter. IL-8 levels determined in 15 group 1 patients increased significantly during CPB, peaked at the end of surgery, and then decreased but remained slightly elevated even at 48 hrs postoperatively. There was a significant correlation between cortisol and IL-8 levels (r = 2.55, p <.05). Children with leukocytosis, tachycardia, and hypotension had lower leptin levels and less variation over time as opposed to those with an uncomplicated course. CPB is associated with acute changes in circulating leptin levels. These changes parallel those in cortisol, demonstrating an inverse relationship between leptin and cortisol. Further studies of the prognostic and therapeutic roles of leptin after CPB should be investigated.

An ergonomic evaluation of surgeons’ axial skeletal and upper extremity movements during laparoscopic and open surgery

Background: Many surgeons have complained of fatigue and musculoskeletal pain after laparoscopic surgery. We evaluated differences in surgeons’ axial skeletal and upper extremity movements during laparoscopic and open operations. Methods: Five surgeons were videotaped performing 16 operations (8 laparoscopic and 8 open) to record their neck, trunk, shoulder, elbow, and wrist movements during the first hour of surgery. We also compared postprocedural complaints of pain, stiffness, or numbness between the two groups. Results: Compared with surgeons performing open surgery, surgeons performing laparoscopic surgery exhibited less lateral neck flexion; less trunk flexion; more internal rotation of the shoulders; more elbow flexion; more wrist supination and wrist ulnar and radial deviation. There was a trend of more shoulder stiffness after laparoscopic operations than after open operations. Conclusions: Laparoscopic surgery involves a more static posture of the neck and trunk, but more frequent awkward movements of the upper extremities than open surgery. Ergonomic changes in the operating room environment and instrument design could ease the physical stress imposed on surgeons during laparoscopic operations.