Postoperative urinary retention following hip or knee arthroplasty under spinal anaesthesia with intrathecal morphine: a retrospective cohort study.

Introduction: Postoperative urinary retention (POUR) frequently complicates the course of patients following hip and knee arthroplasty. Intrathecal morphine (ITM) was identified as a significant risk factor for POUR. The objective of this study was to investigate the incidence and risk factors for POUR in fast-track total joint arthroplasty (TJA) under spinal anaesthesia (SA) with ITM. Methods: We conducted a retrospective study of our institutional joint registry of patients who underwent primary TJA under SA with ITM between October 2017 and May 2021. Preoperative (baseline demographics) and perioperative data were collected. The primary outcome was the incidence of POUR after 8 h or earlier, either due to lack of voiding or according to patient's complaints of bladder distension. Univariate and adjusted analyses were performed to identify predictors of POUR. Results: Sixty-nine patients who underwent total knee arthroplasty (TKA) and 36 patients who underwent total hip arthroplasty (THA) under SA with ITM were included in the study. POUR requiring bladder catheterisation was diagnosed in 21% of patients. Independent predictors of POUR were age over 65 years and male gender. Conclusions: SA with ITM for TJA is associated with high rates of POUR in males older than 65 years of age. Other previously identified risk factors such as intraoperative fluid administration or comorbidities may not be as influential.

Thiamine Administration and the Prevalence of Delirium in the Intensive Care Unit: A Retrospective Before and After Interventional Study.

BACKGROUND: Thiamine is an essential co-factor for aerobic intracellular respiration, nerve conduction, and muscle contraction. Thiamine deficiency is common in the intensive care unit (ICU). Delirium is a frequent unwanted symptom among critical ill patients. Although the exact cause of ICU-associated delirium is unknown, abnormal nutrition and thiamine deficiency may contribute to the etiology. OBJECTIVES: To compare the prevalence of delirium among ICU patients who received thiamine with those who did not and to compare morbidity and mortality. METHODS: A retrospective study was conducted among ICU patients admitted 2014-2018. Routine thiamine administration began in 2016. Collected data included patient demographics, medical history, indication for ICU admission, hospital admission times, ventilation days, inotropic therapy, hemodialysis, tracheostomy, 28-day mortality, and need for anti-psychotic therapy. Group A received thiamine, group B did not. All data were statistically analyzed according to type. RESULTS: The study included 930 patients: 465 patients in group A and 465 in group B. At admission and throughout the hospitalization severity of disease parameters was worse in group A compared to group B, including acute physiology and chronic health evaluation (APACHE) score, admission lactate level, ventilation days, inotropic support, renal replacement therapy, tracheostomy, and ICU hospitalization. Group A had fewer delirium events without difference of maximal delirium score. No difference in mortality rate was observed. CONCLUSIONS: Thiamine administration was associated with lower delirium prevalence despite longer ICU admission times and higher disease severity parameters at admission and during ICU stay.

Drug allergy in hospitalized perioperative patients: the contribution of a structured questionnaire for accurate diagnosis.

AIMS: History of drug allergy is a major cause for deviation from standard of care, as well as prescribing expensive medications. We aimed to evaluate drug allergy-related history taking by surgery interns and compare it with history taking by an allergist and an anesthetist using a simple, structured questionnaire. METHODS: Patients with a declared drug allergy were prospectively recruited from surgical wards. The interns' drug allergy diagnosis was compared with that of the allergy specialist and anesthetist that used a structured questionnaire. RESULTS: A total of 195 patients with 305 reports of drug allergy were included; 52% of the reactions labeled by the surgical interns as allergic were tagged as not allergic by the anesthetist assisted by the questionnaire. The allergist found that 51% of these reactions represented either side effects or were nonrelated to the culprit drug. CONCLUSION: Inconsistency between drug allergy diagnosis of surgery interns and anesthetists and allergists are common. The use of a simple structured questionnaire by the ward physicians may be accessible and beneficial for more precise diagnosis of drug allergies.

Perioperative patient safety: correct patient, correct surgery, correct side--a multifaceted, cross-organizational, interventional study.

BACKGROUND: It is important to ensure a patient-safe environment in the perioperative setting. With this in mind, a "patient-safety first" philosophy was adopted within our operating room service. METHODS: During the first phase of the interventional study (2001-2002), we defined and executed the organizational and educational aspects of the intervention. Thereafter, the implementation phase (2003-2005) was performed. According to our zero tolerance policy, in the event that a major error in patient readiness for anesthesia and surgery was found in the operating room holding area, the patient would be returned to the parent department ("failure") and the surgical procedure delayed until the major error was corrected. RESULTS: The data of 15,856 patients were recorded. During the 3-yr implementation period, 112 patients (0.71%) were returned to the department. A statistically significant (P < 0.002) reduction in major errors was recorded when comparing the year 2003 to the years 2004 and 2005 (1.04, 0.59, and 0.49% for the years 2003, 2004, and 2005, respectively). Furthermore, stepwise logistic regression demonstrated a time-dependant significant decrease in the incidence of a major error that resulted from inadequate patient preparation (odds ratio = 1.48, 95% CI: 1.16-1.87). In addition, the mean time between failures was 6.6, 11.2, and 14.7 days for the years 2003, 2004, and 2005, respectively (P < 0.03). Finally, a significant (P < 0.0001) improvement in patient preparation over time, as well as the overall probability that the patient preparation score = 100% (P < 0.001), were demonstrated. CONCLUSIONS: Education and increased awareness can decrease perioperative errors. However, even with a carefully designed policy in place, an error-free environment was not achieved. Therefore, monitoring and system analysis should be performed on a continuing basis.

Intrathecal anesthesia for elderly patients undergoing short transurethral procedures: a dose-finding study.

One hundred elderly men (> or =65 yr) undergoing transurethral procedures (<45 min) received bupivacaine 7.5 mg, or bupivacaine 5 mg + fentanyl 20 mug, or bupivacaine 4 mg + fentanyl 20 mug, or bupivacaine 3 mg + fentanyl 20 mug, intrathecally. Intraoperative "rescue" fentanyl requirements were higher (P < 0.03) in group bupivacaine 3 mg + fentanyl. Times (min) to ambulation eligibility were decreased in a dose-dependant manner (157 +/- 50 vs 147 +/- 37 vs 128 +/- 40 vs 116 +/- 29, respectively). Of the techniques studied, intrathecal bupivacaine 4 mg + fentanyl 20 mug provided adequate analgesia and was associated with hemodynamic stability and a favorable recovery profile.

Postcesarean analgesia: the efficacy of bupivacaine wound instillation with and without supplemental diclofenac.

STUDY OBJECTIVE: To assess the analgesic efficacy of diclofenac when administered as an adjuvant to bupivacaine wound instillation. DESIGN: Prospective, randomized, double blind, placebo-controlled study. SETTING: Large referral hospital. PATIENTS: 90 women recovering from cesarean delivery performed via a Pfannenstiel incision. INTERVENTIONS: A standard intrathecal anesthetic was administered. On completion of surgery, a multiorifice 20-gauge epidural catheter was placed within the surgical wound. Postoperatively, the catheter was attached to a patient-controlled analgesia (PCA) device programmed to deliver 9 mL with a 60-minute lockout time and no basal infusion. In group bupivacaine-diclofenac, the PCA device delivered 0.25% bupivacaine, and 20 minutes before the end of surgery, patients received intravenous diclofenac (75 mg/100 mL saline). Thereafter, oral diclofenac (50 mg) was administered every 8 hours. In group bupivacaine-placebo, 0.25% bupivacaine and an equal volume of intravenous saline or oral placebo were administered 20 minutes before the end of surgery and every 8 hours thereafter. In group placebo-diclofenac, wound instillation was with sterile water, and 20 minutes before the end of surgery, patients received intravenous diclofenac (75 mg/100 mL saline) and thereafter oral diclofenac (50 mg) at 8-hour intervals. During the first 6 postoperative hours, a coinvestigator administered "rescue" morphine (2 mg, intravenously). Thereafter, subcutaneous morphine (0.05 mg/kg) was administered on patient request for additional analgesia. MEASUREMENTS AND MAIN RESULTS: The number of attempts to activate the PCA device was significantly higher in group bupivacaine-placebo (39 +/- 32) when compared with group bupivacaine-diclofenac (24 +/- 28). During the first 6 postoperative hours, the number of patients requiring rescue morphine and the total rescue morphine administered were significantly different between the groups. During the subsequent 18 hours, subcutaneous morphine administration was significantly higher in group bupivacaine-placebo. Postoperative pain scores were significantly higher in group bupivacaine-placebo when compared with those recorded in groups placebo-diclofenac and bupivacaine-diclofenac. Finally, patient satisfaction was significantly lower in group bupivacaine-placebo. CONCLUSION: In the context of this study, the bupivacaine wound instillation with adjuvant diclofenac administration is associated with similar postoperative analgesia to that induced by diclofenac alone.

The hyponatramia of multiple myeloma is true and not pseudohyponatramia.

The hyponatremia found in multiple myeloma and which is associated with a reduced anion gap (ag) is considered to be pseudohyponatremia due to the displacement of water by the high globulin content in the blood. Serum proteins participate in acid-base balance. Stewart and other authors in their approach to acid-base interpretation acknowledge electrical neutrality as a fundamental characteristic of body fluids. Furthermore, they have shown that both the strong ion difference (SID) and protein, specifically, negatively-charged albumin affect hydrogen ion concentration (H(+)) in the body--i.e., for example an increase in SID leads to a decrease in H(+) and a decrease in albumin leads to a similar effect. The M proteins of multiple myeloma are positively charged. As a result they cause a decrease in sodium levels and the anion gap and thus a true hyponatremia.

Bispectral index monitoring does not improve early recovery of geriatric outpatients undergoing brief surgical procedures.

PURPOSE: To assess if titration of sevoflurane using the bispectral index (BIS) monitor improves the early and intermediate recovery in geriatric outpatients undergoing brief urologic procedures under general anesthesia without muscle relaxants. METHODS: After a standardized induction with propofol and fentanyl, a laryngeal mask airway was inserted and sevoflurane was administered in combination with 60% nitrous oxide in oxygen for maintenance of anesthesia in spontaneously breathing outpatients. In the Control group (n = 25), sevoflurane and fentanyl were titrated according to standard clinical practice. In the BIS-directed group (n = 25), sevoflurane was titrated to maintain a BIS value between 50 and 60, and supplemental fentanyl, 25 mug iv boluses were administered to treat tachypnea. The intraoperative anesthetic and analgesic requirements, as well as the times to eye opening, removal of the laryngeal mask airway device, response to simple commands, orientation to person and place, and postanesthesia care unit discharge eligibility (fast-track score of 14) were assessed at specific time intervals. RESULTS: The minimum alveolar concentration-hour of sevoflurane (0.25 +/- 0.15 and 0.31 +/- 0.2) and end-tidal concentrations of sevoflurane at the end of surgery (0.3 +/- 0.3 and 0.4 +/- 0.20%) did not differ significantly between the Control and BIS-directed groups, respectively. Although the percentage of patients requiring supplemental boluses of fentanyl was reduced in the BIS-directed group (16 vs 48%, P <0.05), the intraoperative BIS values and recovery times were similar in the two groups. CONCLUSION: In this non-paralyzed elderly outpatient surgery population, the use of BIS monitoring for titrating the maintenance anesthetic (sevoflurane) failed to improve the early recovery process.

The frequency and timing of respiratory depression in 1524 postoperative patients treated with systemic or neuraxial morphine.

STUDY OBJECTIVE: To describe the frequency and timing of intravenous patient-controlled analgesia (IV-PCA) or neuraxial morphine-induced postoperative respiratory depression. DESIGN: Audit of data captured by routine quality assurance of the acute pain protocols that were implemented by nurses performing routine postoperative care. SETTING: The surgical wards of a university-affiliated, 700-bed, tertiary hospital. PATIENTS AND INTERVENTIONS: In real time, the data of all patients enrolled into our Acute Pain Service (APS) were entered and stored in the APS database. Thereafter, patients who had received IV morphine via a PCA device or neuraxial morphine between January 1999 and December 2002 were isolated. From this subset, all patients in whom a respiratory rate (RR) less than 10 breaths per minute was recorded were retrieved. MEASUREMENTS AND MAIN RESULTS: From a total of 4500 patients, IV or neuraxial morphine was administered to 1524 patients. Eighteen (1.2%) cases of an RR less than 10 breaths per minute were recorded (13 patients, 4 patients, and 1 patient in the IV-PCA, daily epidural morphine, and single-dose intrathecal morphine groups, respectively). A direct correlation between intraoperative fentanyl administration and postoperative respiratory depression was demonstrated between the IV-PCA (P = 0.03) and epidural groups (P = 0.05). The time from IV-PCA initiation or last neuraxial morphine administration until the diagnosis of respiratory depression ranged between 2 hours and 31.26 hours and 2 hours and 12.15 hours, respectively. Ten (55.6%) patients received naloxone. CONCLUSION: Morphine-induced respiratory depression may occur at any time during the APS admission. However, the optimal frequency of intermittent RR monitoring is unknown. Furthermore, because multiple variables (age, sex, prior opioid administration, site of operation) may affect morphine-induced respiratory depression, further investigation must be performed to determine the ideal monitoring protocol.

The effects of general vs spinal anesthesia on frontal cerebral oxygen saturation in geriatric patients undergoing emergency surgical fixation of the neck of femur.

STUDY OBJECTIVE: To assess the effect of regional vs general anesthesia on transcranial cerebral oxygen saturation (rSo2). DESIGN: Prospective, randomized, open-label study. SETTING: Large referral hospital. PATIENTS: Sixty American Society of Anesthesiologists physical status I, II, and III geriatric patients at least 60 years of age, undergoing surgical fixation of the neck of femur. INTERVENTIONS: Patients were randomized to receive either general (group GA) or spinal (group S) anesthesia. In all cases, frontal rSo2 was measured for a 10-minute preoperative control period, throughout the surgical procedure, and for 10 minutes postoperatively. MEASUREMENT AND MAIN RESULTS: The frequency of a decrease in rSo2 below baseline preoperative levels was significantly (P < .0001) higher in group S. However, the number of patients in whom at least one dip below baseline was recorded was similar between the groups. By contrast, general anesthesia was associated with a significantly higher rSo2 when compared with spinal anesthesia. Logistic regression revealed no correlation between changes in blood pressure, heart rate, or peripheral oxygen saturation and the frequency of rSo2 dips below baseline. CONCLUSION: Cerebral oxygen saturation is likely patient specific and independent of the anesthetic technique administered. Spinal anesthesia is associated with a higher incidence of cerebral desaturation. However, the number of patients in whom at least one dip below baseline was recorded was similar between the groups.

The role of sonography in detecting radial head subluxation in a child.

Injuries around the elbow joint in children can be difficult to diagnose on the basis of findings on physical examination and radiographs. We present the case of a 4-year-old girl with a probable subluxation of the radial head, based on the findings on physical examination and radiographs. Radiography raised the possibility of a radial head subluxation. Sonography demonstrated displacement of the cartilaginous head of the radius away from the capitellum in the affected elbow. The child underwent corrective surgery. During fluoroscopy, results of an ulnar stress test were positive for lateral ligament tears. The patient's arm was put in a cast for 6 weeks. At 1-year follow-up, the patient had full range of motion of the elbow without pain. We present the findings of sonographic studies used to confirm the diagnosis.

The postoperative blood-sparing efficacy of oral versus intravenous tranexamic acid after total knee replacement.

To assess the blood-sparing efficacy of tranexamic acid (TA) administered orally or via a variable IV infusion, 80 healthy patients undergoing elective total knee replacement were studied according to a prospective, controlled, randomized, single-blinded study design. Patients were allocated to one of four treatment groups. In group TA-long, 30 min before deflation of the limb tourniquet, an IV bolus dose of TA 15 mg/kg was administered over 30 min. Thereafter, a constant IV infusion of 10 mg . kg(-1) . h(-1) was administered until 12 h after final deflation of the limb tourniquet. In group TA-short, a similar regimen was followed; however, the constant IV infusion was discontinued 2 h after final deflation of the limb tourniquet (time of discharge from the postanesthesia care unit). Thereafter, oral TA 1 g was administered after 6 and 12 h. In group TA-oral, 60 min before surgery an oral dose of TA 1 g was administered. After surgery, a similar dose of TA was administered every 6 h for the next 18 h. In the control group, TA was not administered. At patient discharge, postoperative allogeneic blood administration was significantly more in group Control when compared with each of the three TA treatment groups. Because oral drug administration is simple and does not require specific infusion equipment, the authors suggest that oral TA is a superior blood-sparing strategy compared with IV drug administration.

The postoperative analgesic efficacy of wound instillation with ropivacaine 0.1% versus ropivacaine 0.2%.

STUDY OBJECTIVES: To assess the influence of ropivacaine concentration on wound instillation-induced postoperative analgesia following total abdominal hysterectomy with bilateral salpingo-oophorectomy. DESIGN: Prospective, randomized, double-blind study. SETTING: Large referral hospital. PATIENTS: 40 ASA physical status I and II patients undergoing total abdominal hysterectomy with bilateral salpingo-oophorectomy. INTERVENTIONS: A standard general anesthetic was administered. In all cases surgery was performed via a Pfannenstiel incision. On completion of the surgery, a multi-orifice, 20-gauge epidural catheter was placed above the fascia such that the tip was sited at the point that demarcated 50% of the length of the surgical wound. Thereafter, the catheter was connected to an electronic patient-controlled analgesia (PCA) device programmed to deliver 9 mL of drug, with a lockout time of 60 minutes and no basal infusion. Patients were randomized to receive PCA with ropivacaine 0.1% (Group 0.1) or ropivacaine 0.2% (Group 0.2). During the first 6 postoperative hours, a co-investigator administered "rescue" morphine (2 mg IV). Thereafter, "rescue" meperidine 1 mg/kg was administered on patient request. MEASUREMENTS AND MAIN RESULTS: The number of attempts to activate the PCA device and actual PCA instillations during the 24 hour study period were similar between the groups. The number of 2 mg "rescue" morphine dosages administered was 4.3 +/- 1.7 versus 4.4 +/- 2.5 for the Group 0.1 and Group 0.2, respectively. For Group 0.1 and Group 0.2, the total dose of "rescue" morphine administered during the first 6 postoperative hours was 8.7 mg +/- 3.6 versus 9.1 mg +/- 5, respectively. "Rescue" meperidine administration during the subsequent 18 hours was similar between the groups. Throughout the study period, pain scores were similar between the groups. CONCLUSION: With a pre-set volume, varying the concentration of ropivacaine (0.1% versus 0.2%) does not affect the analgesic efficacy of wound instillation following total abdominal hysterectomy with bilateral salpingo-oophorectomy.

Establishing a nurse-based, anesthesiologist-supervised inpatient acute pain service: experience of 4,617 patients.

STUDY OBJECTIVE: To describe our nurse-based Acute Pain Services (APS) and present the results of 4617 patients treated by our service. DESIGN: Descriptive audit. SETTING: Large referral hospital. PATIENTS: 4617 patients treated by the APS. MEASUREMENT AND MAIN RESULTS: Analgesic regimens [basic pain treatment, patient-controlled analgesia (PCA), epidural analgesia, spinal analgesia, and wound instillation], as well as the associated patient monitoring and event-response algorithms are detailed. The mean visual analog score (VAS) for pain was low. A VAS for pain greater than 30 mm was noted in 15.3% of all pain scores recorded. Bradypnea (respiratory rate < 10 breaths/min) was recorded in 19 patients (overall incidence = 0.4%). No complications resulting in sustained morbidity or mortality occurred. Of the patients, 96% described their overall satisfaction with the APS as either good or excellent. CONCLUSION: A nurse-based APS provides effective and safe postoperative pain management.

Economic consequences of operative delay for hip fractures in a non-profit institution.

This retrospective study evaluated the economic consequences of delaying hip fracture surgery in 191 elderly patients. Data was collected regarding fracture type, surgery, timing of surgery, background diseases, postoperative hospital stay, and complications. In addition, calculation of the drugs administered to the patients, cost of the surgery, blood transfusion, physiotherapy, laboratory examinations, radiographs, and any financial data were evaluated. Spending more resources for performing hip surgery within 48 hours is more cost-effective than delaying surgery past the third day.

The second hip fracture--an analysis of 84 elderly patients.

OBJECTIVES: Evaluation of patients with a second hip fracture, which means a fracture of the contralateral hip. DESIGN: Retrospective database analysis. SETTINGS: Academic teaching hospital. PATIENTS: All patients who were admitted for their second hip fractures between November 1999 and September 2001 and had their first hip fracture treated in our institution. INTERVENTION: In this study, we epidemiologically analyzed the fracture types, the interval between the two fractures, general status of the patients, type of operation performed, and the postfracture independence level. RESULTS: This survey comprises 84 patients (65 females and 19 males). Their ages ranged from 57 to 91 years (mean: 79) and 58 to 93 years (mean: 82) for the first and the second operation, respectively. The interval between the operations ranged from 2 to 297 months (mean: 35 months, median: 30 months). Twenty-three patients had subcapital fractures in both hips. In 54 patients, bilateral intertrochanteric fractures were noted. Only 7 patients had a previous subcapital fracture and a second intertrochanteric fracture. The general status of the patients' health was defined by the number of pre-existing major medical conditions and was found to be between 0 and 4 (mean: 2.15). Thirty-two patients (38%) had additional fractures somewhere between 1 and 8 years prior to the hip fracture (vertebra, proximal humerus, or distal radius). Sixty-eight and 56 out of the 84 patients reached the same mobility status after the first and second operation, respectively. CONCLUSIONS: A tendency was found for the second hip fracture to be of the same type as the previous one. Most patients showed a good potential for rehabilitation and for maintaining their prefall functional level.

A comparison of three techniques for acute postoperative pain control following major abdominal surgery.

STUDY OBJECTIVES: To compare the analgesic efficacy of a nonsteroidal antiinflammatory drug (NSAID) alone (basic pain treatment) with that of NSAID in conjunction with either intravenous (IV) patient-controlled analgesia (IV-PCA) or intermittent epidural morphine (epidural morphine), among patients recovering from major intraabdominal surgery; and to assess the fixed and variable costs of providing the respective acute pain treatment modalities. DESIGN: Prospective, nonrandomized study. SETTING: Postanesthesia care unit (PACU) and surgical departments of a large referral hospital. PATIENTS: All patients (n = 358) treated by our Acute Pain Service (APS) who were recovering from major intraabdominal surgery (colectomy, cholecystectomy, colostomy, gastrectomy, splenectomy). MEASUREMENTS AND MAIN RESULTS: The structure of our APS, analgesic regimens, and the associated patient monitoring and event-response algorithms are detailed. Data of 358 patients recovering from major intraabdominal surgery and treated according to one of the three treatment protocols were collected and analyzed. The cost of providing our APS and the nursing time required to monitor and treat patients in each treatment group were also calculated. The median visual analog scale (VAS) scores were low in all three treatment groups (23.5 mm vs. 6 mm vs. 4, for the basic pain treatment, IV-PCA, and epidural morphine groups, respectively). However, the median VAS was significantly (p < 0.04) lower among patients who received epidural morphine than either the IV-PCA or basic pain treatment groups. Similarly, the number of patients who had at least one episode of a pain VAS >30 mm was significantly (p < 0.04) lower in the epidural morphine group than either of the other two groups. The frequency of nausea and vomiting was similar among the groups. However, the frequency of postoperative pruritus was significantly (p < 0.001) higher in the epidural morphine group than the other two groups. Patient satisfaction was unaffected by group allocation. Institutional costs per patient and the nursing time required to provide the APS were lowest in the basic pain treatment group. CONCLUSIONS: Considering the respective pain profiles, complication rates, and institutional costs associated with the three analgesic regimens analyzed, the basic pain Treatment alone constitutes a useful alternative to the other two analgesic regimens assessed.

Surgical management of spinal stenosis: a comparison of immediate and long term outcome in two geriatric patient populations.

This retrospective study was performed to assess and compare the immediate safety and long term outcome of surgical decompression of spinal stenosis when performed for geriatric patients aged 65-74 years (Group A) and those >75 years (Group B) of age. Some 283 patients were studied (179 and 104 patients in Groups A and B, respectively). The mean follow-up time was 41.5 months (range: 9-115) and 42.9 months (range: 9-106) for Groups A and B, respectively. Within both treatment groups, there was a significant (P<0.0001) subjective improvement in low back and radicular pain, as well as the ability to perform daily activities. When compared to preoperative levels, the oral scores for pain while performing daily activities were significantly (P<0.001) improved in both treatment groups. The overall postoperative complication rate was similar between the groups. Age is not a contraindication for decompressive lumbar spine surgery. However, since both Group A and B patients are likely to suffer minor perioperative complications, increased vigilance and careful monitoring are essential for this high risk population.

Patient-controlled bupivacaine wound instillation following cesarean section: the lack of efficacy of adjuvant ketamine.

STUDY OBJECTIVE: To assess the analgesic efficacy of ketamine when administered as an adjuvant to bupivacaine for patient-controlled wound instillation following cesarean section. DESIGN: Prospective, randomized, double-blind study. SETTING: Large referral hospital. PATIENTS: 50 term parturients undergoing cesarean section. INTERVENTION: In all cases, a standard spinal anesthetic was administered. On completion of the surgery, a multihole 20 G epidural catheter (B. Braun, Melsungen, Germany) was placed above the fascia such that the tip was sited at the point which demarcated 50% of the length of the surgical wound. Thereafter, the catheter was connected to a patient-controlled drug delivery device. The device was filled with either 0.125% bupivacaine (bupivacaine group) or 0.125% bupivacaine and ketamine (1 mg/mL) (bupivacaine-ketamine group). Postoperatively, wound instillation was performed via the patient-controlled analgesia device. During the first 6 postoperative hours, a co-investigator administered "rescue" morphine (2 mg IV). Thereafter, "rescue" dipyrone (1 g) was administered on patient request. MEASUREMENTS AND MAIN RESULTS: At all time intervals, visual analog scale (VAS) for pain at rest, on coughing, and during leg raise were similar between the groups. All patients (100%) in both treatment groups received "rescue" morphine. Similarly, the number of doses of 2 mg "rescue" morphine administered was unaffected by patient randomization. The total "rescue" morphine administered during the first 6 postoperative hours was 11.2 +/- 4.6 mg versus 11.3 +/- 5.6 mg for the bupivacaine group and bupivacaine-ketamine group, respectively. The number of pump infusions during the 24-hour study period was 9 +/- 2 and 9 +/- 3 for the bupivacaine group and bupivacaine-ketamine group, respectively. The volume infused via the delivery device was similar between the groups (81 +/- 18 mL vs. 85 +/- 24 mL for the bupivacaine group and bupivacaine-ketamine group, respectively). Psychomental and cognitive function as measured by the Digit Symbol Substitution and Mini Mental Tests were unaffected by adjuvant ketamine administration. Patient satisfaction was similar between the groups. CONCLUSION: Adjuvant local ketamine does not enhance bupivacaine-induced wound instillation following cesarean section.