The efficacy of the psoas compartment block versus the intrathecal combination of morphine, fentanyl and bupivacaine for postoperative analgesia after primary hip arthroplasty: a randomized single-blinded study

PURPOSE

Intrathecal morphine and psoas compartment block represent two accepted techniques to provide postoperative analgesia after hip arthroplasty. We designed a prospective, randomized, single-blinded study to compare these two techniques.

METHODS

Forty patients scheduled for primary hip arthroplasty under general anesthesia were randomized to receive either an intrathecal administration of 0.1 mg morphine, 0.015 mg fentanyl and 15 mg hyperbaric bupivacaine (Group I, n = 20) or a psoas compartment block with ropivacaine 0.475% 25 mL (Group II, n = 20). Pain scores, morphine consumption, associated side-effects were assessed for 48 hr postoperatively. In addition, patient's satisfaction and acceptance of the postoperative analgesic technique were also recorded.

RESULTS

During the first 24 hr, pain scores (12 +/- 27 vs 24 +/- 25 at H + 12, 12 +/- 46 vs 20 +/- 26 mm at H + 24, 16 +/- 19 vs 20 +/- 29 mm at H + 36) and tramadol consumption (30 +/- 70 vs 210 +/- 400 mg at H + 12, 180 +/- 120 vs 320 +/- 100 mg at H + 24) were slightly lower in Group I than in Group II, but there were no statistically significant differences. Itching was the most frequent side-effect occurring in 45% of cases in Group I vs 10% in Group II (P < 0.05). No major complication occurred. There was no difference in satisfaction scores between the two groups.

CONCLUSION

Intrathecal administration of a combination of morphine, fentanyl and bupivacaine and single-shot psoas compartment block both provide very good postoperative analgesia after primary hip arthroplasty.

Ropivacaine induced acute neurotoxicity after epidural injection

Ropivacaine is an amide-type long acting local anaesthetic. According to experimental and human data, its toxicity for Central Nervous System (CNS) and Cardiovascular System (CVS) is considered lower than toxicity related to bupivacaine, the now-a-days accepted golden standard for long acting local anaesthetics. Nevertheless, reports about this kind of accidents are fairly numerous. Aim of this short paper is to describe, primarily from a subjective point of view, CNS symptoms a patient (one of the Authors) suffered by an acute toxic reaction during an epidural block, and to stress the need to pay attention to safety measures in the practice of loco-regional anaesthesia and epidural blockade.

Midazolam as an anti-emetic

Benzodiazepines have been involved during the years in the prevention and treatment of Post-Operative Nausea and Vomiting (PONV). Midazolam, a short acting benzodiazepine widely used as a premedicant before surgery, for induction of anaesthesia, and for conscious sedation, has been particularly studied, sometimes with conflicting results. This paper will discuss the possible mechanisms of action of midazolam in PONV management and its fields of application (adults and children undergoing surgery, treatment of persistent postoperative emesis), as far as potentialities of other non-traditional anti-emetics, maybe ready to get out the arena of case reports, and the need of further studies on postoperative anti-emetics in their efficacy in treating established PONV.

A runny nose: an unexpected ferromagnetic foreign body in an unexpected place

A case report about a small child scheduled to undergo brain Magnetic Resonance (MR) imaging first and Computed Tomography (CT) scan next in the same session for coeliachia and possible associate malformative diseases is described. Only by chance the MR procedure has not been carried out, and the CT scan scout view revealed unexpectedly a metallic paper clip deeply embedded in a nasal fossa. The potential of unwelcome side effects and effective safety degree of MR imaging are discussed.

A new method of orotracheal intubation in mice

A new method of orotracheal intubation in mice is described. After intraperitoneal induction of anaesthesia, 36 male animals, belonging to common laboratory strains, have been intubated with the aid of a straight, small bore arthroscope, connected to a video-camera. After the insertion of a guide wire of appropriate size across the vocal cords, a polyethylene (PE) cannula has been introduced over it as an endotracheal tube. Success rate has been 100% both in first intubations and in re-intubations; all procedures have been performed in a mean time of about 3 min. Post-mortem examination of mice did not show any significant damage to upper airway mucosae related to the technique.

An update on Intravenous Regional Anaesthesia of the arm

Intravenous Regional Anaesthesia (IVRA) has been first described in 1908 by the german surgeon August KG Bier. Although the technique was easy to perform and effective in giving surgical anaesthesia, the newer plexus block techniques largely replaced in a short time the "Bier block", because of time limitations of IVRA and safety considerations. Throughout the years modifications in procedure and new pharmacologic adjuvants have been shown to prevent toxic reactions to anaesthetics and mitigate limitations of IVRA. This paper rewiews the technique itself, its historical background, procedural modifications to improve its safety and efficiency, pharmacologic adjuvants acting on onset time of anaesthesia and on tourniquet pain, and drugs improving postoperative analgesia and muscle relaxation. The economic side of IVRA is also discussed.

Anaesthesia for shock wave therapy in musculoskeletal disorders: a preliminary report

The potential for using external applied energy to rectify or ameliorate musculoskeletal disorders has been explored for decades. A shock wave is a pressure disturbance: tissue effect is cavitation, producing microtrauma or microfracture and haematoma formation, inducing, as to date is thought, increase in vascularization, increased soft callus and faster enchondral ossification. Anaesthesiological interest in this field is focused in non-union or delayed osseous union, joint stiffness or osteochondrosis and femoral head necrosis in adults. Actually, because of the pain associated with high energy extracorporeal shock wave therapy on bones, anaesthesia is necessary, but, since almost all patients have no complaint after treatment, there is no need of postoperative analgesia. Therefore, short duration anaesthetic techniques and agents should be preferred. Loco-regional anaesthesia or general anaesthesia are both suitable to the purpose. Fifty patients have been treated nowadays in our Institution with shock wave therapy needing anaesthesia. 18 patients (36%) received general anaesthesia. Since patient's stay in hospital was expected to be short, short duration agents have been used, avoiding those causing unpleasent side effects, first emesis. We used Propofol or Remifentanil by continuous infusion, titrated to maintain stable haemodynamics and an appropriate level of anaesthesia. The short duration of action of Propofol depends on its rapid elimination, whereas Remifentanil undergoes rapid biotransformation to minimally active metabolites. 32 patients (64%) received regional anaesthesia. We avoided long acting agents or high concentration drugs. Spinal blocks have been performed with 0.5% hyperbaric bupivacaine; brachial plexus blocks, sciatic-femoral blocks and an epidural block have been performed with 0.5-1% xylocaine or 1% mepivacaine. Shock Wave Therapy has been done during a 3-day hospital stay. With suitable anaesthesiological treatment and preparation, almost all patients could be treated as outpatients or with an overnight hospital stay.

Intra-articular analgesia following arthroscopic surgery of the shoulder

Shoulder surgery is very often followed by severe postoperative pain. Loco-regional anaesthesia has greatly contributed as a solution of this problem. Nevertheless most of surgery is still performed under general anaesthesia. In this case many different methods have been proposed in order to mitigate postoperative pain. Intra-articular administration of local anaesthetics after shoulder surgery is not yet in routinely clinical practice. In this study efficacy of intra-articular administration of Ropivacaine versus Bupivacaine has been evaluated. Analysis of results showed both drugs to share the same effectiveness within four hours postoperatively. In subsequent period (6-24 hours) Ropivacaine demonstrated to provide a statistically significant better postoperative pain relief. Furthermore Ropivacaine group patients needed postoperative analgesics to a lesser extent than Bupivacaine group. The long-losting satisfactory level of analgesia, particularly with Ropivacaine, could recommend the use of intra-articular analgesia even for day-hospital or one-day surgery procedures.

Wake-up test during major spinal surgery under remifentanil balanced anaesthesia

Damage to spinal cord and subsequent neurological deficit is a recognised complication of major spinal surgery. It may be produced by a number of causes, not last excessive stretching when surgical instrumentation is positioned; it is easy to understand that early intraoperative warning of potential damage is highly desiderable. Wake-up test is a simple, safe and reliable method of recognition of such a complication, allowing rapid neurological recovery by reduction of spinal distraction. Remifentanil belongs to a new pharmacokinetic class of opioids (EMO: Esterase Metabolised Opioid) undergoing rapid biotransformation to minimally active metabolites, showing a short and predictable duration of action with no effect of accumulation. Authors describe a first 10 patient series subjected to wake-up-test during spinal surgery under remifentanil balanced anaesthesia. The protocol the authors set up allowed a very rapid intraoperative neurological examination (in average less than 5 min), without pain and/or disagreement for the patient and no complication related to the test was observed. Authors conclude that the use of Remifentanil for intraoperative awakening during major spinal surgery seems to be a safe, reliable and pratictical method to detect very quickly any potential neurological damage during the operation.

Detection of arrhythmogenic cellular magnesium depletion in hip surgery patients

The use of high-dose magnesium infusions in critically ill and surgical patients is increasing. This practice is associated with considerable risk of toxicity, as no reliable criteria are currently available to detect significant intracellular magnesium depletion. We have evaluated, before and after surgery, 33 elderly patients with hip fracture, by 24-h Holter ECG monitoring, Doppler echocardiography and serum chemistry; lymphocyte magnesium was measured using atomic absorption spectrophotometry. The severity of ventricular arrhythmias increased, and serum and mononuclear magnesium concentrations decreased significantly after surgery. Decreases in either serum magnesium concentrations > 0.125 mmol litre-1 or cellular magnesium > 6 nmol mg-1, but not serum or lymphocyte absolute magnesium concentrations, were associated with postoperative development of repetitive arrhythmias. Variations in serum magnesium concentrations correlated with intracellular decreases, and yielded good accuracy in predicting the postoperative worsening of arrhythmias. Thus perioperative differences in serum magnesium concentrations reflected intracellular variations and allowed us to identify patients with clinically relevant cellular magnesium depletion.

Cost effective prophylaxys of postoperative nausea and vomiting by anesthetic premedication

Postoperative emesis is a common daily problem in anesthetic practice. Authors report their experience about prevention of PONV (postoperative nausea and vomiting) with the association of different drugs in premedication, and suggest Promethazine as an effective and inexpensive medication to prevent PONV in orthopedic surgery.

Intubating conditions with propofol under muscle relaxation with vecuronium bromide. A time-related comparison with thiopental

In the present study a comparison has been made between intubating condition obtainable after anesthesia induction with Thiopental or Propofol, using Vecuronium Bromide to achieve muscle relaxation. Data were collected about hemodynamic parameters, vocal cords position, coughing or bucking, and involuntary movements. Three-hundred patients, males and females, ASA classes I and II, not premedicated, were included in the study; they all had to undergo surgery requiring tracheal intubation. The patients were divided in six different groups, and in each of them intubation was performed at different times from injection of inducing agents (2-2, 30-3-4-5-6 minutes). Overall results show a lack of satisfying intubating conditions on the extreme of selected times (2 and 5-6 minutes), with no significant difference between Thiopental and Propofol, except for a minimal unlike behaviour in hemodynamics. Therefore, on the basis of our data, as far as intubating conditions are considered, we can conclude that there is no reason to prefer one of the two inducing agents.

Intravenous premedication with atropine and postanesthetic delirium. Report of two cases

The authors report two cases of postanesthetic delirium in patients receiving intravenous atropine sulphate before surgery. In the first case the diagnosis of atropinic syndrome has been suggested by a cause effect relationship; in the second case the diagnosis has been supported by the prompt resolution after intravenous physostigmine salycilate administration. Since such syndrome was never observed in patients receiving atropine sulphate as i.m. premedicant, authors are prone to consider the i.m. route a safer approach to premedication with this drug.

[An unusual cause of obstruction of the anesthesia circuit ]

The authors report an unusual accident, uneventful for the patient, due to the mobilization of a foreign body (a piece of tape) inside the anaesthesia circuit, following Emergency Oxygen administration. The accident dynamics and the safety of anaesthesia equipment are discussed.

[Cerebral amino acid metabolism in acute barbiturate poisoning]

An experimental study on the protein and aminoacid cerebral metabolism in Barbiturate poisoning coma has been carried out. Some significant alterations in central aminoacid pattern have been found. These changes suggested Hypothesis on particular biochemical pathways of brain tissue related to the pathological status. An attempt of correlation between the aminoacid alterations and cerebral energetic need is also reported.

Changes in plasma and cerebrospinal fluid electrolytes in hypercapnia

A study on two groups of patients in acute respiratory failure with hypercapnia (18 subjects) and in hypercapnic coma (18 subjects) has been carried out to determine the related changes in sodium ion, potassium ion, chloride ion, urea and osmolality in blood and cerebrospinal fluid. There were significant differences between the two pathological states and particularly in coma, changes in transmembrane active transport of electrolytes are significantly related to high concentrations of CO2 in the brain.