Effect of preemptive multimodal analgesia for arthroscopic knee ligament repair.

BACKGROUND AND OBJECTIVES: Administration of analgesic medication before surgery, rather than at the completion of the procedure, may reduce postoperative pain. Similarly, administration of multiple analgesics, with different mechanisms of action, may provide improved postoperative pain control and functional recovery. The purpose of our study was to compare pain scores and intravenous opioid consumption after outpatient anterior cruciate ligament (ACL) reconstruction in patients who received a multimodal drug combination (intravenous [IV] ketorolac, intra-articular morphine/ropivacaine/epinephrine, and femoral nerve block with ropivacaine) either before surgery or immediately at the completion of the surgical procedure. METHODS: Forty patients presenting for same-day arthroscopic ACL repair using a semitendinosis tendon graft were included in this study. The patients were randomized to receive the following drugs either 15 minutes before skin incision or immediately after skin closure: (1) Ketorolac 30 mg IV. (2) Intra-articular injection of 20 mL ropivacaine 0.25% + morphine 2 mg and epinephrine 1:200,000. (3) Femoral nerve block with 20 mL ropivacaine 0.25%. Verbal pain scores were obtained in the postanesthesia care unit (PACU) and on postoperative days 1, 3, and 7. IV patient controlled analgesia (PCA) morphine consumption in the PACU was also recorded. RESULTS: Verbal pain rating scores were lower in group I (preemptive) for 2.0 hours after arrival in the PACU. There was no difference between groups in pain scores on postoperative days 1, 3, and 7. Mean IV PCA morphine consumption in the PACU was lower in group I (6.4 mg) versus group II (12.3 mg), P <.05. CONCLUSION: Preemptive, multimodal administration of our 3-component analgesic drug combination resulted in lower pain scores during the initial stay in the PACU unit and lower consumption of IV PCA morphine in the PACU. However, pain scores were similar in both groups on postoperative days 1, 3, and 7; thus, there was no measurable long-term advantage associated with preemptive multimodal drug administration.

Adding low dose meperidine to spinal lidocaine prolongs postoperative analgesia.

PURPOSE: To investigate the effects of the addition of low dose meperidine to spinal lidocaine on the sensory and motor blockade profile, and the quality and duration of postoperative analgesia. METHODS: In a randomized double blind prospective dose finding study 40 patients undergoing transurethral prostatectomy with spinal anesthetic were allocated to receive 75 mg lidocaine 5% intrathecally as the sole agent (group A), or co-administered with 0.15 mg x kg(-1) meperidine (group B) or 0.30 mg x kg(-1) meperidine (group C). Sensory and motor blockade profiles were documented. Postoperatively, the amount of analgesics required, time to first analgesic, visual analogue scores and adverse events were recorded. RESULTS: Sensory blocks at or above T10 was maintained for 128, 156 and 145 minutes in groups A, B and C respectively. There was no difference in the latency or duration of the motor block among the three groups. Patients in group C had lower visual analogue pain scores (VAPS) over time than did those in groups A and B (P < 0.05). Time to first analgesia was longer (429 +/- 197 minutes) in group C than in group A (254 +/- 157 minutes) (P < 0.05). Fewer patients in group C required parenteral opioid postoperatively than in group A (P < 0.05). The incidence of bradycardia was higher in the groups receiving meperidine. No symptoms of transient radicular irritation (TRI) were reported in the groups receiving meperidine. CONCLUSION: The addition of 0.3 mg x kg(-1) of meperidine to spinal lidocaine prolongs postoperative analgesia without delaying discharge from post anesthetic care unit (Table II) and reduces the requirement for parenteral analgesics (Table III).

Pre-incision infiltration with lidocaine reduces pain and opioid consumption after reduction mammoplasty.

BACKGROUND AND OBJECTIVES: To determine the analgesic efficacy of preoperative tumescent infiltration with lidocaine for reduction mammoplasty. METHODS: Women with mammary hypertrophy were randomly allocated to one of two study groups in a double-blind clinical trial. Patients in group 1 received preincision infiltration with 5 mL/kg of 0.35% lidocaine with 1:1,000,000 epinephrine into each breast after induction of general anesthesia. Group 2 patients received similar injections of 5 mL/kg of saline with 1:1,000,000 epinephrine. Intravenous patient-controlled analgesia (PCA) morphine (1.0 mg bolus with 5-minute lockout) was available for 9.5 hours in the postoperative period. Visual analog pain scores were recorded during the postoperative period, and hourly morphine consumption data were retrieved from the PCA apparatus. Fitness for discharge was evaluated by the postanesthesia care unit nurse using standardized discharge criteria. RESULTS: Visual analog pain scores were higher in group 2 patients until 3.5 hours after surgery. Patients in the saline group had higher intravenous morphine consumption during all 1-hour postoperative intervals, although the differences between groups were statistically significant only until 4.5 hours after the operation. Total intravenous morphine consumption during the first 9.5 hours after surgery in group 1 was 16.9+/-11.9 mg versus 31.1+/-18.0 mg in group 2 (P < .05). Postoperative nausea and vomiting occurred with equal frequency (87%) in both study groups, and there was no difference between groups in time to achieve fitness for discharge, i.e., a postanesthesia discharge score of > or = 9. CONCLUSION: Preoperative tumescent infiltration with lidocaine results in reduced pain and lower postoperative opioid requirements in the initial hours after reduction mammoplasty.

Densities of cerebrospinal fluid and spinal anaesthetic solutions in surgical patients at body temperature.

PURPOSE: To determine the densities of cerebrospinal fluid (CSF) in patients for surgery under spinal anaesthesia. The densities of the CSF were compared with the densities of local anaesthetic solutions and their mixtures with commonly used spinal opioids. METHOD: One ml of CSF was collected from 131 consecutive patients that consented to the study at the time of spinal anaesthesia. Densities were measured at 37 degrees C in a Density Meter that displayed density to the fourth decimal point and was accurate to 0.00003 g.ml-1. The densities of a selection of spinal anaesthetic drugs were also measured. RESULTS: The mean CSF density in the study population was 1.00059 +/- SD 0.00020. In men of all ages, the mean CSF density was 1.00067 +/- 0.00018 g.ml-1; in postmenopausal women 1.00060 +/- 0.00015 g.ml-1; in premenopausal non-pregnant women 1.00047 +/- 0.00076 g.ml-1; and in pregnant women 1.00033 +/- 0.00010 g.ml-1. There were differences between the CSF densities in pregnant women compared with men (P = 0.0001), postmenopausal women (P = 0.0001) and non-pregnant premenopausal women (P = 0.03). Local anaesthetic solutions that contain sugar (glucose or dextrose) were all hyperbaric. In the absence of sugar, all local anaesthetic solutions were hypobaric except for lidocaine CO2 which was slightly hyperbaric. Opioids were all hypobaric except meperidine which was hyperbaric. CONCLUSION: Pregnant women have slightly lower CSF densities than do men and postmenopausal women, and non-pregnant premenopausal women. In the absence of sugar all spinal anaesthetic solutions measured were hypobaric except for lidocaine CO2 and meperidine, both of which were hyperbaric.

Peri-operative multimodal pain therapy for caesarean section: analgesia and fitness for discharge.

PURPOSE: To compare, the efficacy of a multi-modal analgesic regimen and single drug therapy with iv PCA morphine alter Caesarean delivery with spinal anaesthesia. METHODS: Forty ASA 1-2 parturients presenting for elective Caesarean section were randomized to receive multimodal pain treatment with intrathecal morphine, incisional bupivacaine and ibuprofen+acetaminophen po until hospital discharge (Group 1) or conventional therapy with iv PCA morphine weaned to acetaminophen+codeine po (Group 2). Both groups received spinal anaesthesia with 1.7 ml hyperbaric bupivacaine 0.75%. Visual analog pain scores at rest (RVAPS) and with movement (DVAPS) were recorded q 2 hr during the first 24 hr, then q 4 hr until discharge. Time to first walking, eating solid food, flatus, bowel movement, voiding and hospital discharge were recorded. RESULTS: Pain scores were lower in Group 1 patients during the first 24 hr after spinal injection RVAPS 0.6 +/- 0.1 in Group 1 vs 2.1 +/- 0.1 in Group 2 (mean +/- SEM), DVAPS 1.9 +/- 0.1 in Group 1 vs 4.1 +/- 0.1 in Group 2 (P < 0.0001). Times to first flatus, 36.1 hr +/- 2.9 vs 20.5 +/- 1.8 (P < 0.05) and to first bowel movement, 74.8 hr +/- 5.6 vs 57.4 +/- 4.7 (P < 0.0001) were longer in Group 2 patients. There was no difference between groups in time to eating solid food, walking or hospital discharge. CONCLUSION: Multi-modal pain therapy resulted in improved early post-operative analgesia during the first 24 hr after Caesarean delivery. Patients receiving iv PCA morphine followed by acetaminophen+codeine po were more likely to develop decreased bowel mobility. All patients, with one exception, achieved discharge criteria (eating solid food, absence of nausea, normal lochia, dry incision and DVAPS < 4) at 48 hr after spinal injection.

Airway and respiratory management following non-lethal hanging.

PURPOSE: To review the literature on airway and respiratory management following non-lethal (suicidal) hanging and to describe the anatomy, injury and pathophysiological sequelae and their impact on patient care. SOURCE: A Medline literature search of English-language and English-abstracted papers for 1990-96. Keywords were hanging; strangulation; airway obstruction; pulmonary oedema. Filters were applied to limit the search to relevant citations. (i.e., keywords = pulmonary oedema; filters = postobstructive, neurogenic). Citations were then hand-culled to obtain current and relevant papers about an unusual cohort of patients. A hand search of the bibliographies of relevant papers supplemented the Medline search. A review of our experience at the University of Ottawa adult hospitals over the last decade was also undertaken to determine the relevance of the literature to our clinical experiences. PRINCIPAL FINDINGS: Most victims are young men and survivors are uncommon. Laryngo-tracheal injuries, although reported in 20-50% of postmortem examinations, are infrequent in survivors and have little impact on airway management. Spinal injuries are rare in survivors but should be excluded. Pulmonary complications including pulmonary oedema and bronchopneumonia are implicated in most in-hospital deaths. Pulmonary oedema is likely due to neurogenic factors or negative intrathoracic pressure. Although neurological injury determines outcome following hanging, initial neurological presentation is of limited prognostic value: a poor initial condition does not exclude a good recovery. CONCLUSION: Airway injuries severe enough to interfere with airway management are uncommon after attempted suicide by hanging. Irrespective of the initial neurological assessment, aggressive and early resuscitation to optimize cerebral oxygenation is recommended.

Postarthroscopy analgesia with intraarticular bupivacaine/morphine. A randomized clinical trial.

BACKGROUND: Postarthroscopy analgesia has been provided with intraarticular bupivacaine, but the duration of analgesia may be only a few hours. More recently, longer-lasting analgesia has been achieved using intraarticular morphine, although the onset of analgesia may be delayed. The combination of intraarticular morphine and bupivacaine has been suggested as an ideal analgesic after knee arthroscopy. METHODS: One hundred and twenty ASA Physical Status 1-2 outpatients, age 18-60 yr, having knee arthroscopy, were randomized into one of four treatment groups. Exclusion criteria included relevant drug allergy, extensive debridement or synovectomy, arthrotomy, postoperative intraarticular drainage, tracheal intubation, and patient refusal. All patients received general anesthesia with intravenous fentanyl, propofol, N2O, O2, and isoflurane. At the end of surgery, before tourniquet release, the following were injected intraarticularly through the arthroscope: group 1, 0.25% bupivacaine; group 2, 1 mg morphine in saline; group 3, 2 mg morphine in saline; and group 4, 1 mg morphine in 0.25% bupivacaine. The volume injected was 30 ml, and all solutions contained 1:200,000 epinephrine. Postoperative analgesia was provided with intravenous fentanyl and/or oral acetaminophen/codeine, and was recorded for 24 h. Visual analog pain scale (VAPS) scores and the McGill Pain Questionnaire (MPQ) were performed hourly from 1-6 h, and at 24 h postoperatively. RESULTS: Visual analog pain scale and MPQ scores were lowest in groups 1 and 4 at 1-6 h, but at 24 h, VAPS scores were lowest in groups 2, 3, and 4. Analgesic requirements were lower for the first 12 h in groups 1 and 4, but no difference was seen between groups over the 24-h study period. No adverse effects were noted. CONCLUSIONS: Morphine, 1 mg intraarticular, in 30 ml 0.25% bupivacaine, with 1:200,000 epinephrine, may provide superior postoperative analgesia for up to 24 h versus bupivacaine or morphine alone.

Baricity and the distribution of lidocaine in a spinal canal model.

The role of the baricity of local anaesthetic solutions in determining the distribution of local anaesthetics injected into the subarachnoid space (and hence the level of anaesthesia) has been challenged. A recent study found no difference in the extent of cephalad spread of hyperbaric and isobaric solutions and concluded that density had no effect on the spread of local anesthetics. The present study, to determine the validity of this conclusion, utilized a spinal model filled with a "cerebrospinal fluid equivalent." Following the injection of hyperbaric lidocaine, the local anaesthetic was most concentrated at the lower end of the column, whereas following the injection of isobaric solution the local anaesthetic was most concentrated around the site of injection. Therefore, baricity is an important determinant of local anaesthetic distribution in the subarachnoid space.

Site specific endonuclease from Fusobacterium nucleatum.

Four different isolates of Fusobacterium nucleatum (A,C,D and E) contain restriction endonucleases of differing specificity. Whilst many of the endonucleases are isochizomers of known enzymes, two novel activities are Fnu DII which recognizes and cleaves the sequence 5'-CGCT-3'/3'-GCGC-5' AND Fnu EI which recognizes and cleaves the sequence 5'-GATC-3'/3'-CTAG-5' irrespective of the extent of methylation of the adenine residues.

A restriction enzyme from Fusobacterium nucleatum 4H which recognizes GCNGC.

A site-specific restriction endonuclease Fnu4H I isolated from Fusobacterium nucleatum 4H recognizes the DNA nucleotide sequence 5'G C N G C-3'/3'-C G N C G-5' and cleaves as indicated by the arrows.