Controlled-release oxycodone is better tolerated than intravenous tramadol/metamizol for postoperative analgesia after retinal-surgery

PURPOSE

We assessed the clinical efficacy and tolerance of controlled-release oxycodone (CRO), comparing it with intravenous tramadol/metamizol combination in this prospective, randomised, double-blind study of 35 ASA physical status I-III patients undergoing retinal-surgery.

METHODS

General anaesthesia using remifentanil and propofol was performed for surgery. On arrival in the recovery room patients were randomly allocated to two groups. The controlled-release oxycodone group (CRO Group) received 10 mg CRO. 12 h after the initial dose another 10 mg CRO were administered. Simultaneously with the initial CRO dose, and every 4 h up to 24 h postoperatively, the CRO Group received intravenous isotonic saline infusion. On arrival in the recovery room the tramadol/metamizol group (TM Group) received a placebo tablet, and 12 h later a second placebo. Simultaneously 100 mg tramadol combined with 1 g metamizol were administered intravenously every 4 h until 24 h postoperatively. All patients had access to intravenous opioid rescue medication.

RESULTS

The AUC for quality of analgesia was significantly higher in the CRO Group than in the TM Group (p = 0.0023). Patient rated quality of analgesia significantly higher in the CRO Group than in the TM Group 8 h (p = 0.048), 16 h (p = 0.009) and 24 h (p = 0.001) postoperatively. There was no statistical difference in AUC for pain scores between groups (p = 0.205). The CRO Group experienced significantly less nausea than the TM Group (p = 0.012). Six patients in the TM Group in contrast to none in the CRO Group interrupted the study before finishing the study protocol (p = 0.022).

CONCLUSIONS

We conclude that CRO administered twice in the first 24 h postoperatively is superior to intravenous tramadol/metamizol for postoperative analgesia after retinal surgery, with fewer adverse events and greater patient satisfaction.

Antiplatelet therapy preceding coronary artery surgery

BACKGROUND AND OBJECTIVE

Bleeding after cardiac surgery correlates with morbidity and mortality. The aim of this study was to determine the influence of antiplatelet therapy on bleeding and transfusion rates in coronary artery bypass grafting.

METHODS

Forty patients receiving aspirin and/or clopidogrel/ticlopidine within 7 days prior to surgery were retrospectively compared to 40 control patients lacking antiplatelet therapy for at least 8 preoperative days. Blood loss was assessed as chest-tube drainage during the first 12 h after surgery. Units transfused were recorded intraoperatively and during stay in the intensive care unit.

RESULTS

Both groups were comparable for pre- and intraoperative data. Irrespective of single or combined antiplatelet therapy, treated patients demonstrated lower fractions of the creatine-kinase isoenzyme MB (5.8 +/- 3.1 vs. 8.2 +/- 4.1%; P = 0.004) and infarction rates (0 vs. 3; P = 0.240) than control patients, but had significantly more haemorrhages (940 +/- 861 mL vs. 412 +/- 590 mL; P = 0.002) and transfusion requirements (red cells: 4.5 +/- 4.9 vs. 1.5 +/- 2.3, plasma: 4.9 +/- 6.4 vs. 1.3 +/- 2.5, platelets: 1.5 +/- 1.3 vs. 0.1 +/- 0.2; all P < or = 0.001). The differences to control patients were more pronounced for only short antiplatelet therapy free intervals or ongoing antiplatelet therapy (P < or = 2 days < or = 0.019). For antiplatelet therapy free intervals longer than 2 days, bleeding and transfusion rates (except for platelets) were nonsignificantly higher as compared to control patients (P > or = 0.058).

CONCLUSIONS

To overcome increased blood loss and transfusion rates, antiplatelet therapy should be discontinued for at least 2 days before elective coronary surgery. Whether patients at high risk for myocardial infarction might benefit from ongoing antiplatelet therapy remains to be investigated.

Interleukin-6 enhancement after direct autologous retransfusion of shed thoracic blood does not influence haemodynamic stability following coronary artery bypass grafting

BACKGROUND

Direct autologous retransfusion of shed thoracic blood is carried out to reduce homologous transfusion after cardiac surgery, but it contains high concentrations of inflammatory mediators. The purpose of the study was to investigate whether retransfusion of shed thoracic blood induces plasma interleukin-6 (IL-6) expression and influences haemodynamics.

METHODS

Following uncomplicated coronary artery bypass graft surgery, forty-four patients were randomised in case postoperative blood loss via thoracic drains exceeded 350 ml. The course of plasma IL-6 levels and haemodynamics including cardiac output, extravascular lung water and intrathoracic blood volume were investigated prior to (T0), 30 minutes (T1), 1 (T2), 3 (T3) and 12 hours (T4) after retransfusion of 350 ml shed blood in comparison to 350 ml saline.

RESULTS

Plasma IL-6 levels at T1 (1892 +/- 202 vs. 485 +/- 30 pg/ml) and T2 (1059 +/- 119 vs. 413 +/- 30 pg/ml) were significantly higher in the verum group (n = 20) compared to controls (n = 24) ( P < 0.01). Severe haemodynamic side effects were not detected.

CONCLUSION

This study found significantly elevated plasma IL-6 levels following direct autologous retransfusion of shed thoracic blood but failed to show severe adverse effects affecting haemodynamic stability.

Rahmenbedingungen für eine intakte Hämostase

A coagulopathy is an independent predictor of perioperative mortality. Therefore, maintenance of a functional coagulation system is an essential precondition to reduce morbidity and mortality in the perioperative setting. Sound coagulability also depends on prerequisites such as body temperature, acid-base balance, plasma calcium concentration and haematocrit. Severe trauma or perioperative bleeding can gravely influence these factors and boost the blood loss. Common global tests of coagulation are not helpful in this setting because they are conducted on plasma with a normalised temperature of 37 degrees C, an excess of calcium and a stabile acid-base balance. Hence, knowledge of the effects of altered prerequisites is a premise to avoid a possibly lethal coagulopathy. According to the current literature, an increased risk for clinically significant coagulopathy exists with a body temperature <or=34 degrees C, an acidosis <or=7.15, ionised calcium under 0.9 mmol/l or a haematocrit under 30-35%. A combination of these factors deteriorates the coagulopathy and hypothermia in addition to acidosis is especially harmful. Prevention of derangement of these factors should start as early as possible, i.e. in trauma patients at the scene of the accident and should be continued in the operating room.

Risk stratification models fail to predict hospital costs of cardiac surgery patients

BACKGROUND

The aim of this prospective study was to determine if commonly used risk stratification models can predict total hospital costs in cardiac surgical patients.

METHODS

Between October 1st and December 31st 2003, all consecutive adult patients undergoing cardiac surgery on CPB at our institution were classified using seven risk stratification scoring systems: EuroSCORE, Cleveland, Parsonnet, Ontario, French, Pons, and CABDEAL. Total hospital costs for each patient were calculated on a daily basis including preoperative diagnostic tests, operating room costs, disposable materials, drugs, blood components, costs for personnel, and hospital fixed-costs. Linear regression analysis was used to determine the correlation between costs and the seven risk stratifications models as well as length of stay (LOS) on ICU. The Spearman correlation coefficient was calculated from the regression line, and an analysis of residuals was performed to determine the quality of the regression.

RESULTS

A total of 252 patients were operated for CABG (n=175), valve (n=39), CABG plus valve (n=21), thoracic aorta (n=13) and miscellaneous (2 myxoma, 1 ASD, 1 pulmonary embolism). Mean age of the patients was 66.0+/-11.4 years, 29.4% were female. LOS on ICU was 3.3+/-6.3 days and the 30-day mortality rate was 6.7%. Spearman correlation between the seven risk stratification models and hospital costs was below r=0.32 (p=0.0001), but was r=0.94 (p=0.0001) between ICU LOS and costs.

CONCLUSIONS

Total hospital costs can be identified by length of ICU stay. None of the common risk stratification models accurately predicted total hospital costs in cardiac surgical patients.

A survey of autologous blood transfusion practices in Germany

This survey was designed to evaluate the use of autologous blood transfusion techniques in Germany in 2000 and to identify how the use of these techniques has changed over the past 5 years. Questionnaires were mailed to the chief anaesthesiologists of 400 randomly selected German hospitals with > or =25 surgical beds. Information was sought about the current and past use of preoperative autologous blood donation (PABD), acute preoperative haemodilution and peri-operative blood salvage. Data were requested for the calendar year 2000. Three hundred and forty-three (86%) completed questionnaires were returned. PABD, haemodilution and peri-operative blood salvage were used by 85, 54 and 67% of respondents, respectively. Thirty-seven per cent of PABD users reported that PABD use declined, 28% reported that it increased and 34% reported that it remained unchanged over the past 5 years. The proportions of those reporting declining vs. increasing use of PABD did not differ significantly (P = 0.09). Sixty per cent of users of haemodilution reported that its use declined, 10% reported that it increased and 29% reported that it remained unchanged over the past 5 years. Sixteen per cent of hospitals that were equipped with cell-washing devices reported that the use of these devices declined, 47% reported that it increased and 37% reported that it remained unchanged over the past 5 years. The results indicate that autologous blood transfusion techniques were widely used in Germany in 2000, with PABD being the most common technique. The use of PABD did not change significantly, the use of haemodilution declined markedly and the use of peri-operative cell salvage increased markedly during the past 5 years before the survey.

["Relaxant" awake but still relaxed]

We report on a 23-year-old female patient who underwent removal of the implants after maxillary surgery. At the end of surgery the administration of anaesthetic agents was discontinued. During the following 30 min several attempts were made to wake the patient, but she did not respond to verbal or pain stimuli. No changes in heart rate, blood pressure vegetative reactions such as sweating, lacrimation, or mydriasis were noted. Protective reflexes like coughing could not be elicited. After 30 min neuromuscular monitoring was applied and indicated residual muscle paralysis after the use of mivacurium. The patient was again sedated and transferred to the ICU, where she was mechanically ventilated for an additional 9 h. An atypical cholinesterase was determined as the underlying reason for the prolonged action of mivacurium. Retrospectively, the patient remembered the attempted wake-up period in detail. However, she reported no feelings of fear or helplessness because she had faith in the anaesthesiologist, a close friend of the patient's family for many years, who kept her calm and comfortable by talking to her during the entire period. Several months after the incident, the patient reported having neither increased fear of surgery nor any negative psychological effects on her life following this incident of awareness.

Accidental tenfold overdose of propofol in a 6-month old infant undergoing elective craniosynostosis repair

We report a 6-month-old male infant undergoing elective craniosynostosis repair who accidentally received a tenfold dose of propofol over a 4-h operative period. Myocardial dysfunction was observed after nearly 3 h of infusion; this could not solely be explained by the propofol overdose.

The effect of preoperative antiplatelet therapy in coronary artery surgery: blood transfusion requirements for patients on cardiopulmonary bypass

INTRODUCTION

Bleeding after heart operations remains a common complication and contributes to morbidity and death. Recent studies have suggested that antiplatelet therapy (APT) may not increase homologous blood requirements in coronary bypass surgery. The purpose of this study was to examine the influence of APT therapy on haemorrhage and transfusion requirements in patients undergoing coronary artery bypass (CABG) on cardiopulmonary bypass (CPB).

MATERIALS AND METHODS

Records from 290 consecutive patients who underwent CABG with CPB were retrospectively reviewed, including 145 patients who received APT within 5 days prior to surgery and 145 control patients (CON). Blood loss was measured up to 24 h. Demographic and clinical patient data were collected until hospital discharge.

RESULTS

Both groups were well matched with respect to demographic and intra-operative data. There was significantly (p < 0.0005) more mediastinal tube drainage at 24 h in the APT group (1123 mL +/- 537 mL) compared to CON patients (874 mL +/- 351 mL). In addition, the APT group received significantly more units of blood (APT: 2.6 +/- 2.5 vs CON: 1.6 +/- 1.8; p < 0.0005), platelet units (APT: 1.2 +/- 1.8 vs CON: 0.2 +/- 0.8; p < 0.0005), and fresh frozen plasma units (APT: 2.0 +/- 2.2 vs CON: 1.3 +/- 2.0; p = 0.01).

CONCLUSION

This study suggests consideration should be given to delaying elective CABG for patients who have received APT treatment until APT is discontinued for at least 5 days.

Tinnitus nach An�sthesie

Possible connections between different forms of anaesthesia and the occurrence of tinnitus or increasing levels of tinnitus are described. After general anaesthesia no increase in the occurrence or level of tinnitus is to be expected, but there exists a very rare, but specific form of low frequency tinnitus combined with low frequency sensory hearing loss following spinal anaesthesia. Reversible tinnitus and hearing disorders following local anaesthesia normally occur in cases of central nervous system toxicity.

Impact of tranexamic acid vs. aprotinin on blood loss and transfusion requirements after cardiopulmonary bypass: a prospective, randomised, double-blind trial

INTRODUCTION

Aprotinin (AP) reduces blood loss and transfusions after cardiopulmonary bypass (CPB), but may sensitise patients and is expensive. Tranexamic acid (TA) has less side-effects, but data regarding its efficacy are controversial. The aim of our prospective, randomised, double-blind study was to compare the impact of AP vs. TA on drainage blood loss and transfusion requirements in patients undergoing first time CABG on CPB.

MATERIALS AND METHODS

One hundred and twenty adult patients were randomised to receive either high-dose AP according to Hammersmith or a total of 2 g TA. Perioperative blood products were transfused in a standardised fashion. Blood loss was measured up to 24 h. Demographic and clinical patient data were collected until hospital discharge.

RESULTS

The data from 118 patients (TA: n = 58, AP: n = 60) who completed the study according to protocol were analysed. Blood loss at 24 h postoperation in TA patients was significantly higher (896 +/- 354 ml) as compared to AP patients (756 +/- 347 ml; p = 0.03). TA patients received 1.5 +/- 1.5 units of red blood cells (AP: 1.5 +/- 1.7, p = 1.0), 1.3 +/- 2.0 units of fresh frozen plasma (AP: 1.0 +/- 2.0, p = 0.38) and 0.5 +/- 1.4 units of platelets (AP: 0.2 +/- 0.7, p = 0.15). Clinical data, including perioperative myocardial infarction rate, acute renal failure, mechanical ventilation, hospital stay and mortality, were not significantly different between either group.

CONCLUSION

Our data show a difference in blood loss between TA and high-dose AP. Although statistically significant, it has little clinical relevance, because perioperative transfusion requirements were similar for both groups. Thus, TA appears to be a cost-effective alternative to AP in primary CABG patients.

Pharmacological characteristics and side effects of a new galenic formulation of propofol without soyabean oil*

We compared the pharmacokinetics, pharmacodynamics and safety profile of a new galenic formulation of propofol (AM149 1%), which does not contain soyabean oil, with a standard formulation of propofol (Disoprivan 1%). In a randomised, double-blind, cross-over study, 30 healthy volunteers received a single intravenous bolus injection of 2.5 mg.kg-1 propofol. Plasma propofol levels were measured for 48 h following drug administration and evaluated according to a three-compartment model. The pharmacodynamic parameters assessed included induction and emergence times, respiratory and cardiovascular effects, and pain on injection. Patients were monitored for side effects over 48 h. Owing to a high incidence of thrombophlebitis, the study was terminated prematurely and only the data of the two parallel treatment groups (15 patients in each group) were analysed. Plasma concentrations did not differ significantly between the two formulations. Anaesthesia induction and emergence times, respiratory and cardiovascular variables showed no significant differences between the two treatment groups. Pain on injection (80 vs. 20%, p < 0.01) and thrombophlebitis (93.3 vs. 6.6%, p < 0.001) occurred more frequently with AM149 than with Disoprivan. Although both formulations had similar pharmacokinetic and pharmacodynamic profiles the new formulation is not suitable for clinical use due to the high incidence of thrombophlebitis produced.

Intracranial placement of a nasotracheal tube after transnasal trans-sphenoidal surgery

Intracranial misplacement of a tracheal tube during attempted nasotracheal intubation is a rare, usually lethal complication. Such incidents are associated with fractures of the face and base of the skull. We report inadvertent intracranial placement of a nasotracheal tube in a patient who had 2 weeks previously undergone transnasal trans-sphenoidal surgery for a pituitary tumour. One should be aware that transnasal trans-sphenoidal surgery leaves a bony defect in the skull, which is susceptible to perforation by nasally introduced tubes.

Concept for postoperative analgesia after pedicled TRAM flaps: continuous wound instillation with 0.2% ropivacaine via multilumen catheters. A report of two cases

Pedicled TRAM flap surgery is a complex procedure characterised by an extensive wound site. We present two patients with efficient postoperative pain relief by continuous wound instillation of ropivacaine 0.2% via two multilumen catheters. The catheters were placed subcutaneously before the wound closure through the umbilicus into the abdominal wound, and under the autologous flap into the breast. Each multilumen catheter provides even distribution for local anaesthetics over 12.5 cm. At the end of surgery, patients received a single shot dose of local anaesthetic via the pain catheters. After surgery the continuous infusion of ropivacaine 0.2% was commenced at a rate of 10 ml/h per catheter. Pain scores at rest and on coughing were low on the first postoperative day, and later zero. No medication for breakthrough pain was required throughout the recovery period, and the patients experienced no adverse events linked to the analgesia scene. Patient satisfaction was excellent, and quality of recovery score was superior.

Epidural combination of ropivacaine with sufentanil for postoperative analgesia after total knee replacement: a pilot study

BACKGROUND AND OBJECTIVE

We assessed the analgesic efficacy of postoperative epidural infusions of ropivacaine 0.1 and 0.2% combined with sufentanil 1 microg mL(-1) in a prospective, randomized, double-blinded study.

METHODS

Twenty-two ASA I-III patients undergoing elective total-knee replacement were included. Lumbar epidural blockade using ropivacaine 0.75% was combined with either propofol sedation or general anaesthesia for surgery. After surgery, the epidural infusion was commenced. Eleven patients in each group received either an epidural infusion of ropivacaine 0.1% with 1 microg mL(-1) sufentanil (Group 1) or ropivacaine 0.2% with 1 microg mL(-1) sufentanil (Group 2) at a rate of 5-9 mL h(-1). All patients had access to intravenous pirinatrimide (piritramide) via a patient-controlled analgesia (PCA) device.

RESULTS

Motor block was negligible for the study duration in both groups. There was no significant difference with the 100 mm visual analogue scale (VAS) scores, with the consumption of rescue analgesia or with patient satisfaction. Patients in Group 1 experienced significantly less nausea (P < 0.05) than those in Group 2. Both treatment regimens provided effective postoperative analgesia with only a minimal use of supplemental opioid PCA.

CONCLUSIONS

We recommend the use of ropivacaine 0.1% with 1 microg mL(-1) sufentanil for postoperative analgesia after total knee replacement as it provides efficient pain relief with no motor block of the lower limbs. In addition, compared with 0.2% ropivacaine with sufentanil, the mixture reduces local anaesthetic consumption without compromise in patient satisfaction or VAS scores. Patients even experience less nausea.

[Mydriasis not reacting to light during an uneventful esophagectomy--drug-related side effect of Akrinor?]

We present a 72 year old patient who underwent an esophagectomy uneventfully. At the end of the procedure the anaesthetist diagnosed a mydriasis not reacting to light. The mydriasis lasted for 3 hours. 30 minutes after diagnosis a cranial computed tomography scan showed no abnormalities. The tracheal tube was removed after 16 h of artificial ventilation, the patient was awake and responded to questions. The neurological examination was normal, as well as the control CT scan. With regard to a mydriasis the following differential diagnosis have to be considered: cerebral ischemia, cerebral hematoma, metabolic encephalopathy, shock, and a drug side effect. We state that an alpha-mimetic effect of the drug mixture Akrinor, the patient had received shortly before diagnosis of the mydriasis, is the most likely explanation. One 2 mls syringe contents of 200 mg norephedrine-ethyl-theophylline and 10 mg noradrenaline-ethyl-theophylline.

[Cesarian section and local anaesthesia: insufficient spread of spinal anaesthesia with hyperbaric bupivacaine 0.5%/5% glucose compared to hyperbaric bupivacaine 0.5%/8% glucose?]

In our hospital hyperbaric Carbostesin 0.5% (AstraZeneca) had been substituted by hyperbaric Bucain 0.5% (Curasan) and both drugs were believed to be identical in their actions.However, both local anaesthetics differ in the amount of glucose they contain. We report about three patients who underwent cesarian section under spinal anaesthesia. In two patients we observed an insufficient spread of spinal anaesthesia after administration of hyperbaric Bucain 0.5%. The third patient received the normally used combination of hyperbaric Carbostesin 0.5% and fentanyl and the subarachnoid block proceeded completely uneventfully. According to the literature the clinical efficacy of hyperbaric Carbostesin 0.5% and hyperbaric Bucain 0.5% should be identical and therefore a critical dilution of the Bucain should not have occurred because of the addition of fentanyl.

Comparison of continuous epidural infusion of ropivacaine and sufentanil with intravenous patient-controlled analgesia after total hip replacement

We assessed the efficacy of an epidural infusion of ropivacaine 0.1% and sufentanil 1 microg x ml(-1), comparing it with intravenous patient-controlled analgesia using piritramide in this prospective, randomised, double-blind study of 24 ASA physical status I-III patients undergoing elective total hip replacement. Lumbar epidural block using ropivacaine 0.75% was combined with either propofol sedation or general anaesthesia for surgery. Epidural infusion and patient-controlled analgesia were started after surgery. Twelve patients received an epidural infusion of ropivacaine 0.1% and sufentanil 1 microg x ml(-1) at a rate of 5-9 ml x h(-1) and an intravenous patient-controlled analgesia device loaded with saline. Eleven patients received an epidural infusion of saline at the same rate and intravenous piritramide via the patient-controlled analgesia device. Motor block was negligible in both groups. The epidural ropivacaine group had significantly lower visual analogue pain scores at rest 4 h after surgery (p < 0.01), and on movement 4 h (p < 0.01) and 8 h (p < 0.05) after surgery, than the intravenous piritramide group. The piritramide group experienced significantly more adverse events than the epidural group (p < 0.001), especially hypotension (p < 0.01) and vomiting (p < 0.05). Patients in the epidural ropivacaine group were more satisfied with the pain management (p < 0.05). We conclude that the epidural infusion of ropivacaine 0.1% and sufentanil 1 microg x ml(-1) is superior to intravenous opioid by patient-controlled analgesia in preventing pain after total hip replacement, with fewer adverse effects and greater patient satisfaction.

Evaluation of a new hydroxyethyl starch solution (HES 130/0.4) in patients undergoing preoperative autologous blood donation

STUDY OBJECTIVE

To compare the tolerance and efficacy of the new hydroxyethyl starch (HES) 130/0.4 with a current HES solution (HES 200/0.5) in patients undergoing preoperative autologous blood donation as a model of surgical blood loss. HES 130/0.4 is expected to be a plasma substitute as efficacious as current HES solutions while offering such advantages as more complete renal elimination and reduced tissue storage.

DESIGN

Controlled, randomized, double-blind, phase II clinical trial.

SETTING

1500-bed university hospital.

PATIENTS

60 ASA physical status II and III patients scheduled for elective cardiac and noncardiac surgery, and meeting selection criteria for autologous blood donors.

INTERVENTIONS

Collection of 500 mL of blood with simultaneous intravenous (IV) infusion of 500 mL of either HES 130/0.4 or HES 200/0.5 (mean molecular weight 130 kD and 200 kD, degree of substitution 0.4 and 0.5, respectively).

MEASUREMENTS

Noninvasive measurements of heart rate and arterial blood pressure were obtained every 5 minutes until 1 hour after blood donation and infusion of the study drugs; laboratory studies (complete blood counts, electrolytes, markers of renal and liver function) were performed; and follow-up assessment of adverse events was undertaken by questionnaire 24 hours after blood donation and infusion of the study drugs.

MAIN RESULTS

Both hemodynamics and laboratory test results did not differ significantly between the groups at any time. Hemodynamics remained stable in each group, and no adverse event was observed in any patient until one hour after blood donation and infusion of the study drugs. Adverse events elicited by postphlebotomy questionnaire were mild and probably unrelated to HES infusion.

CONCLUSIONS

Intravenous infusion of 500 mL of the new HES 130/0.4 was tolerated well and maintained cardiovascular stability in patients undergoing preoperative autologous blood donation. HES 130/0.4 proved equivalent to HES 200/0.5 in every measured respect. Its pharmacokinetic profile may render HES 130/0.4 an attractive alternative to current HES solutions.

Survival from a lethal blood concentration of cyanide with associated alcohol intoxication

We present a patient with a lethal blood concentration of cyanide. Additionally, he was found to have an alcohol blood level of 270 mg. dl-1, but made a complete recovery following administration of the antidotes dimethylaminophenol and thiosulphate. It is postulated that the patient may have been able to detoxify himself as a result of metabolism of cyanide to the non-toxic form, thiocyanate.

Postoperative analgesia with no motor block by continuous epidural infusion of ropivacaine 0.1% and sufentanil after total hip replacement

We assessed the analgesic efficacy of postoperative epidural ropivacaine 0.1% with and without sufentanil 1 microgram/mL in this prospective, randomized, single-blinded study of 30 ASA physical status I-III patients undergoing elective total hip replacement. Lumbar epidural block using 0.75% ropivacaine was combined with either propofol sedation or general anesthesia for surgery. After surgery, the epidural infusion was commenced. Fifteen patients in each group received either an epidural infusion of 0.1% ropivacaine with 1 microgram/mL sufentanil (R + S) or 0.1% ropivacaine without sufentanil (R) at a rate of 5-9 mL/h. All patients had access to i.v. piritramide via a patient-controlled analgesia device. The R + S group consumed six times less piritramide over a 48-h infusion period than the R group (median 12.7 vs 73.0 mg; P < 0.001). Motor block was negligible for the study duration in both groups. Patient satisfaction was excellent. The incidence of adverse events, such as nausea, was similar. We conclude that a continuous epidural infusion of 0.1% ropivacaine with 1 microgram/mL sufentanil is more effective than ropivacaine alone in treating pain after elective hip replacement without motor block.

IMPLICATIONS

This is the first randomized study comparing the efficacy of the epidural combination of ropivacaine 0.1% and sufentanil 1 microgram/mL versus plain ropivacaine 0.1% in treating pain after hip replacement. We found that ropivacaine 0.1% and sufentanil 1 microgram/mL led to a sixfold reduction in opioid requirements after total hip replacement by producing a negligible motor block.

Effects of hypertonic saline hydroxyethyl starch solution on collagen-induced platelet aggregation and ATP secretion

OBJECTIVE

The purpose of this study was to investigate the effect of hypertonic (NaCl 7.5%) hydroxyethyl starch (HES 6%, molecular weight 200,000) (HHES) as used for small-volume resuscitation on global coagulation parameters and platelet function.

DESIGN

Randomized, controlled clinical trial.

SETTING

Intraoperative volume loading after induction of general anesthesia.

PATIENTS

27 consecutive patients [mean age 59 (22-76) years, mean body weight 69.8 (46-98) kg] undergoing abdominal surgery were studied.

INTERVENTIONS

Global coagulation tests (aPTT: activated partial thromboplastin time; PT: prothrombin time; platelet count; thrombelastography: TEG), platelet aggregation and ATP release were measured before and 10 min after the application of 4 ml.kg-1 of HHES (study group H, n = 14) or HES (control group C, n = 13).

RESULTS

The aPTT was prolonged and platelet count was significantly reduced in both study groups. In contrast to the HES group, clot formation time in the TEG was significantly prolonged and the maximum amplitude was reduced in the HHES group. Furthermore, platelet aggregation was significantly slowed down, whereas ATP release significantly increased in the HHES group.

CONCLUSION

The changes in global coagulation parameters can be explained by dilutional effects of the infused solution. The hyperosmolar saline compound of the HHES solution obviously contributes to the slowing down of platelet aggregation. Osmotic stress and membrane pleating may aggravate HES-induced changes in membrane fluidity and microviscosity and thus explain this impaired interaction. The increase in ATP release suggests a change in receptor-second messenger interaction for delta granule release.