Enhanced recovery program (ERP) in major laryngeal surgery: building a protocol and testing its feasibility

Enhanced recovery programs (ERP) represent a multimodal approach to perioperative patient care. The benefits of ERP are well demonstrated in colorectal surgery and Enhanced Recovery After Surgery (ERAS®) programs, that epitomise the ERP concept, have being introduced in different specialties, including vascular, gastric, pancreatic, urogynecologic and orthopaedic surgery. However, no ERP has been proposed for head and neck surgery. We developed an expert-opinion-based ERP for laryngeal surgery based on the key principles of colorectal surgery ERAS®. Twenty-four patients undergoing major laryngeal surgery (total and partial laryngectomies or surgical removal of oropharyngeal tumour with muscle flap reconstruction) were treated according to such an ERP protocol, which differed under several respects from our previous standard practice (described in 70 consecutive patients who underwent major laryngeal surgery before ERP implementation. The adherence rate to the different ERP items is reported. Adherence to ERP items was high. Nutritional assessment, antibiotic prophylaxis, postoperative nausea and vomit (PONV) prophylaxis and postoperative speech therapy targets were applied as required in 100% of cases. Some ERP items (antibiotic prophylaxis, intraoperative infusion rate, and postoperative speech therapy) were already frequently implemented before ERP adoption. Postoperative medical complications occurred in 8.3% of patients. Our expert opinion-based ERP protocol for major laryngeal surgery proved feasible. The degree of benefit deriving from its implementation has yet to be assessed.

A randomised controlled trial of intrathecal blockade versus peripheral nerve blockade for day-case knee arthroscopy

We allocated 100 patients scheduled for day-case knee arthroscopy to unilateral spinal anaesthesia with 40 mg intrathecal hyperbaric prilocaine or to ultrasound-guided femoral-sciatic nerve blockade with 25 ml mepivacaine 2%, 50 participants each. The median (IQR [range]) time to walk was 285 (240-330 [160-515]) min after intrathecal anaesthesia vs 328 (280-362 [150-435]) min after peripheral nerve blockade, p = 0.007. The median (IQR [range]) time to home discharge was 310 (260-350 [160-520]) min after intrathecal anaesthesia vs 335 (290-395 [190-440]) min after peripheral nerve blockade, p = 0.016. There was no difference in time from anaesthetic preparation to readiness for surgery.

Systemic adverse events during 2005 phacoemulsifications under monitored anesthesia care: a prospective evaluation

BACKGROUND

The aim of the study was to evaluate the systemic adverse events triggering on-call anesthesiologist's intervention during 2005 phacoemulsification under topical anesthesia on a day-surgery monitored anesthesia care regimen.

METHODS

Adverse events triggering an anesthesiologist call by the attending nurse were registered. Comorbidities (7 categories), age, gender, body mass index, ASA status, length of surgery, time of the day of surgery and operated eye (first/second) were analyzed as potentially predictive factors. Odds Ratios are expressed as OR (95% CI).

RESULTS

The anesthesiologist was called in 433 (21.6%) cases: age (5-yr-OR 0.95 [0.91-0.99]), ASA status 3-4 (OR 1.37 [1.02-1.85]), positive neurological history (OR 1.60 [1.06-2.40]), positive psychiatric history (OR 2.56 [1.34-4.93]) and length of surgery (OR 1.03 [1.01-1.06]) were predictive of the anesthesiologist call. Arterial hypertension (10.3%) and agitation (9.5%) were the most frequent adverse events. Age (5-yr-OR 1.27 [1.16-1.38]) and ASA status 3-4 (OR 1.83 [1.30-2.56]) were predictive of arterial hypertension. Age (5-yr-OR 0.80 [0.76-0.85]), positive neurological history (OR 1.86 [1.10-3.14]) and positive psychiatric history (OR 4.48 [2.26-8.88]) were predictive of agitation. Interruption of surgery was never required.

CONCLUSION

One-day cataract surgery performed under topical anesthesia with monitored anesthesia care required anesthesiologist intervention in 21.6% of cases, mainly because of agitation or hypertension. Agitation occurred more often in younger patients with neurological or psychiatric comorbidities. Hypertension occurred more often in older patients with higher ASA scores.

Influence of operating conditions on ceramic ultrafiltration membrane performance when treating textile effluents

This work studies the performance of three commercial ceramic ultrafiltration membranes (ZrO(2)-TiO(2)) treating raw effluent from a textile industry. The effect of crossflow velocity at 3, 4 and 5 m s(-1) as well as membrane characteristics, such as molecular weight cut-off (30, 50 and 150 kDa), on process performance were studied. Experiments were carried out in concentration mode in order to observe the effect of volume reduction factor simultaneously. Results showed a combined influence of both crossflow velocity and molecular weight cut-off on flux performance. TOC and COD removals up to 70% and 84% respectively were reached. On the other hand, almost complete color (>97%) and turbidity (>99%) removals were achieved for all the membranes and operating conditions.

Midazolam and pethidine versus propofol and fentanyl patient controlled sedation/analgesia for upper gastrointestinal tract ultrasound endoscopy: a prospective randomized controlled trial

BACKGROUND AND OBJECTIVES

The aim of this prospective, randomized study was to compare the standard regimen of midazolam and pethidine administered by the gastroenterologist versus patient controlled sedation with a propofol-fentanyl mixture during upper gastrointestinal tract endoscopic ultrasonography. Our primary end-points were patient satisfaction and patient cooperation assessed by endoscopist.

METHODS

Fifty-four consecutive patients, undergoing endoscopic ultrasonography, received sedation with midazolam and pethidine (Group M: n=27) or propofol and fentanyl (Group P: n=27). Group M: pethidine 0.7mg/kg midazolam 0.04mg/kg before examination; boluses of same drugs if the sedation was insufficient plus a sham patient controlled sedation analgesia; Group P: propofol 17mg plus fentanyl 15microg before examination and a patient controlled sedation analgesia pump containing 170mg propofol plus 150microg fentanyl injecting 0.5ml every time the patient pressed the button (no "lock out"). Boluses of 1ml of the same mixture if the sedation was insufficient.

RESULTS

Group M: mean dosage of pethidine and midazolam 88.6 and 5mg, respectively. Group P: mean dosage of propofol and fentanyl 119.7mg and 106microg, respectively. Both groups were similar for duration and difficulty of the procedure, the grade of sedation (Observer's Assessment of Alertness/Sedation Score) and judgement by endoscopist and patient about cooperation and satisfaction. The only difference between groups was about the extra boluses administered during the procedure.

CONCLUSION

This study demonstrated that a patient controlled sedation analgesia with propofol and fentanyl is an effective and safe technique for upper gastrointestinal tract endoscopic ultrasonography procedures and results in a high level of satisfaction both for patients and operator.

Muscle enzyme elevation after elective neurosurgery

BACKGROUND

Serum creatine kinase and myoglobin elevation has been described involving muscle manipulation after surgery and also after bariatric, urologic and gynaecologic procedures. It encompasses a wide range of severity, reflecting in the worst cases true rhabdomyolysis. We occasionally noted creatine kinase elevations after intracranial neurosurgery, an occurrence that has not yet been described. To assess whether the issue of postoperative muscle enzyme elevation is relevant to neurosurgery, we prospectively measured serum creatine kinase and myoglobin in a series of neurosurgical patients submitted to craniotomy.

MATERIALS AND METHODS

We studied 30 patients aged 22-69 yr submitted to craniotomy. Blood samples were taken prior to the procedure, at the end of anaesthesia and on the first, second and third postoperative days. Blood was checked for creatine kinase, myoglobin, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, creatinine and serum electrolytes. We recorded the patient's age, sex, height, weight and body mass index. Throughout surgery, we recorded the highest and the lowest body temperature and sampled the mean arterial pressure at 5 min intervals. We performed backwards stepwise logistic regression analysis to identify the elements that best correlate with the development of cell muscle damage.

RESULTS

On the first postoperative day creatine kinase peaked from baseline (305 (107-1306) UI L(-1) vs. 59 (42-94) UI L(-1); P < 0.001) while myoglobin rose significantly from baseline to the end of surgery (70 (42-147) ng mL(-1) vs. 36 (3044) ng mL(-1); P = 0.002). Logistic regression showed that length of surgery was the only factor clearly influencing peak creatine kinase (P < 0.001; R2 0.7) and myoglobin (P = 0.011; R2 0.41) concentration.

CONCLUSIONS

Creatine kinase and myoglobin elevation may occur after intracranial neurosurgery. In our series, length of surgery was a risk factor.

An Italian survey of severe head trauma management during extracranial surgery

BACKGROUND AND OBJECTIVE

Anaesthetic drugs and procedures interfere with secondary brain injury following severe head trauma, yet studies regarding the anaesthetic management of these patients are lacking. We investigated the behaviour of Italian anaesthetists regarding this topic.

METHODS

A questionnaire investigating the approach to a patient with severe head trauma requiring an urgent splenectomy for ruptured spleen was sent to 250 Italian anaesthetists. Questions regarded the pre-, intra- and postoperative phases, and concerned the rationale use and availability of specific monitoring systems, and indications for invasive procedures and use of drugs, fluids and blood products.

RESULTS

There were 162 (64.8%) responders. Seventy-five percent believed that early tracheal intubation within the emergency room was necessary, while 25% postponed it to the operating room. Basic monitoring was defined as essential by all responders, 147 (90.7%) considered invasive arterial pressure monitoring to be essential. Fifty-seven (84%) anaesthetists working in hospitals without neurosurgical facilities would have transferred the patient after splenectomy. Prophylactic hyperventilation was frequently used (36%). Sixty-eight percent of responders would have preferred in intracranial pressure monitoring inserted before laparotomy, but only 35% actually had this possibility. In case of acute intraoperative arterial hypotension after splenectomy, 54% of the responders advocated the use of blood or blood products to optimize peripheral oxygen transport.

CONCLUSIONS

More widespread knowledge of certain areas of severe head trauma management such as early tracheal intubation, avoidance of prophylactic hyperventilation, adequate invasive monitoring, appropriate use of blood products, and timing of transfer to hospitals with neurosurgical facilities is needed.

Surgical tracheostomy versus percutaneous dilatational tracheostomy. A prospective-randomized study with long-term follow-up

BACKGROUND

To compare surgical tracheostomy (ST) versus percutaneous dilatational tracheostomy (PDT) in terms of complication rates. In particular we specifically studied the late tracheal complications of both methods by means of endoscopic controls of patients up to 6 months after the procedures.

METHODS

DESIGN

prospective-randomized clinical study.

SETTING

University-affiliated tertiary care referral hospital.

PATIENTS

50 consecutive translaryngeally intubated patients with respiratory failure were randomized to undergo either ST (25 patients) or endoscopic guided PDT (25 patients).

RESULTS

ST was performed in 41+/-14 min versus 14+/-6 min for PDT (p<0.0001). There was no procedure-related death. In the ST group there were no intraoperative complications. In the PDT group 2 intraoperative complications (minor hemorrhages) were observed. In the ST group 9 early postoperative complications occurred: one minor bleeding, 7 stomal infections and one accidental decannulation. In the PDT group only one early postoperative complication (minor bleeding) occurred. Early postoperative complication rates were 36% for ST and 4% for PDT. In the ST group there were no late tracheal complications. In the PDT group 2 late tracheal complications (one segmental malacia and one stenosis at the level of the stoma) were observed.

CONCLUSIONS

This study confirms that PDT is a simpler and quicker procedure than ST and that it has a lower rate of early postoperative complications. Late tracheal complications were more frequent, although the difference was not statistically-significant, in the PDT group. Further investigations of long-term outcome following PDT are therefore necessary.

[Percutaneous or surgical trachetomy. Prospective, randomized comparison of the incidence of early and late complications]

BACKGROUND

To compare early and late complications after either conventional surgical or percutaneous dilatational tracheostomy.

DESIGN

Prospective, randomized study.

SETTING

General intensive care unit and neuro-surgical intensive care unit in a university hospital.

PATIENTS

50 consecutive patients, requiring tracheostomy for prolonged mechanical ventilation.

INTERVENTIONS AND MEASUREMENTS

Patients were randomly allocated to receive either surgical (surgical group, n = 25) or percutaneous dilatational tracheostomy (percutaneous group, n = 25). Occurrence of perioperative complication were carefully evaluated during ICU stay. Late complications were evaluated with both physical and endoscopic examination at 1, 3 to 6 months after tracheostomy.

RESULTS

All surgical and percutaneous tracheostomies were successfully completed and no deaths directly related to the tracheostomy procedures were reported. Completion of the procedure required 41 +/- 14 min in the surgical group and 14 +/- 6 min in the percutaneous one (p < 0.0001). The incidence of early perioperative complications was higher in the surgical group (36%) than in percutaneous one (12%), (p < 0.05). The endoscopic follow-up demonstrated one segmental malacia and one stenosis of the trachea in the percutaneous group only (p = n.s.). Skin repair was better after percutaneous tracheostomy than in the surgical group (p < 0.01).

CONCLUSIONS

In experienced hands, percutaneous dilatational tracheostomy is as safe and effective as the conventional surgical tracheostomy. The percutaneous technique is less time-consuming and has a lower rate of early infectious complications with better cosmetic results than the surgical technique.

Complications of internal jugular vein retrograde catheterization

We report on the incidence of complications of 172 internal jugular vein retrograde catheterizations (IJVRCs) performed on 126 patients. Standard cannulation and X-ray control of the catheter tip placement were performed. Difficulties encountered during the manouvre were registered. Patients with a jugular catheter in place for more than one day had neck echography on catheter removal and one week later. Carotid artery puncture occurred in 20 (12%) cases and lymphatic vessel puncture in one. In 13 (8%) cases IJVRC failed due to difficulties in advancing the guide. X-ray films documented catheter misplacement in 39 (23%) cases: loop into the internal jugular vein in 11 (6%); paravertebral venous plexus cannulated in one; other extracranial jugular afferent cannulated in 4 (2%); catheter tip into the jugular lumen in 10 (6%); catheter tip beyond the jugular bulb in 13 (8%). First neck echography documented: one perivascular hematoma (absent one week later); 3 (4%) jugular vein thrombosis (2 asymptomatic and absent one week later; one symptomatic and still evident one week later). Positive neck echography was not associated with difficulties, length of catheterization, diameter of the catheter. IJVRC is a simple and safe procedure with a low incidence of serious complications.

[Seizures associated with acute subarachnoid hemorrhage. Emergency diagnosis and treatment]

Seizures and convulsive status in patients with subarachnoid haemorrhage are an emergency. They are not only known to increase cerebral metabolic rate but also cerebral blood flow and intracranial pressure and rebleeding can occur in patients with an unclipped aneurysm. The goal of therapy is to stop the seizures minimizing the risk of secondary brain damage (hypoxia, hypotension, hypercarbia, hyperthermia). Several active drugs are available for treating seizures, it is important to identify the cause, prompt administration, monitoring the patients and choosing the one with less side effects.

7.5% hypertonic saline versus 20% mannitol during elective neurosurgical supratentorial procedures

This prospective randomized clinical study was designed to compare the effects of equal volumes of 7.5% hypertonic saline solution (HS) or 20% mannitol (M) on brain bulk and lumbar cerebrospinal fluid pressure (CSFP) during elective neurosurgical procedures (aneurysm, arteriovenous malformation, or tumor). After informed consent, 50 American Society of Anesthesiologists physical Status I (ASA I) patients were randomly assigned to M (n = 25) or HS (n = 25) groups. Anesthesia protocol was identical for both, and variables monitored included mean arterial blood pressure (MAP), heart rate (HR), central venous pressure (CVP), CSF pressure (CSFP), arterial blood gases (PaCO2 30-35 mm Hg), serum sodium, potassium, and osmolality, and diuresis. The study period started before hypertonic solution administration (T0) and ended at the opening of the dura mater or 60 min after T0. Data were assessed with repeated measures analysis of variance and Student t test with Bonferroni correction (p < or = 0.05). MAP and CVP were the same in the two groups. After treatment, osmolality increased, and the increase at T15 was higher in HS-treated patients [316.6 +/- 9.3 vs. 304.0 +/- 12.0 (SD) mOsmol/kg; p < 0.001]. Sodium decreased after M and increased after HS. During the study, brain bulk was always considered satisfactory. CSFP was not different between M and HS groups and significantly decreased overtime (p = 0.0056) with no difference between treatments. The results of the present study demonstrate that hypertonic saline is as effective as mannitol in reducing the brain bulk and the CSFP during elective neurosurgical procedures under general anesthesia.

Hypertonic saline fluid therapy following brain stem trauma

Intravenous hypertonic fluid therapy has been proposed to improve secondary ischemic injury after cerebrospinal trauma. We report the case of a 14-year-old boy with vasospasm of the intracranial vertebral arteries and ischemic brain stem damage following head trauma. The patient presented with severe tetraparesis and somatosensory (SSEPs) and brain stem auditory evoked potentials (BAEPs) impairment. The patient was treated with two subsequent hypertonic saline (HS) infusions, 2.7% and 5.4%, respectively, for a period of 48 sp, followed by standard hypervolemic therapy. After the first treatment with 2.7% HS, improvement of SSEPs without neurological improvement was apparent. Relative hypervolemia was subsequently maintained by administration of crystalloids and 20% albumin for 48 h. During standard hypervolemic therapy, no clinical and/or electrophysiological change occurred. The second infusion of 5.4% HS was concomitant with further amelioration of SSEPs and improvement of motor performance. Twelve hours after the second HS infusion, the neurological status returned to preinfusion levels, while SSEPs showed no further changes. BAEPs never changed during fluid therapy. No complication occurred secondary to the infusion of HS. This case report suggests that local improvement of brain stem perfusion following hypertonic fluid therapy accounts for or relevantly contributes to the neurological and SSEPs improvement of the patient.

Neurologic symptoms after epidural anaesthesia. Report of three cases

We describe 3 patients, who exhibited neurological symptoms after single dose epidural anaesthesia. In patient 1 an unrecognized spinal arteriovenous fistula (AVF) caused paraparesis following epidural block. The dilated veins draining an AVF are space-occupying structures and the injection of the anaesthetic solution may have precipitated latent ischaemic hypoxia of the spinal cord due to raised venous pressure. In patient 2, epidural block was followed by postoperative permanent saddle pain and hypoaesthesia. The injection of the anaesthetic in a narrow spinal canal with multiple discal protrusions and restriction of interlaminar foramina may have acutely produced mechanical compression of the spinal cord or roots. Patient 3 exhibited post-epidural block spinal arachnoiditis. Although the few reported cases of this syndrome exhibit severe neurological damage, our patient presented with scarse symptoms. Our cases point out the importance of accurate neurological history and examination of candidates for epidural anaesthesia and of accurate anaesthetic history for neurological patients.

Combined central and peripheral acute demyelination

We describe a patient with multiple sclerosis who had a bout of central demyelination associated with an acute inflammatory demyelinating polyneuropathy. The contemporary involvement of central and peripheral nervous system due to a demyelinating disease has been reported anecdotically in humans, and can be induced experimentally in animals. It may be sustained by a common pathogenetic factor.

Neurological examination in patients recovering from general anesthesia

We performed serial neurological evaluations on 86 patients who underwent surgery for herniated lumbar disk during the first 3 hours after the end of anesthesia (isoflurane-N20-02 for 25 patients, halothane-N20-02 for 38, fentanyl-droperidol-N20-02 for 23). At time 0, the idiomuscular response to percussion of the extensor carpi muscle was present in every patient, while tendon reflexes were always absent. Hyperreflexia was as frequent as shivering, but it took place earlier; we could determine no correlation between these two phenomena. There was no correlation between shivering and rectal temperature of the patients. Although almost all the patients were cooperative and could correctly calculate 100-7, the post-hyperventilation-apnea test was positive in 35 patients at time 120 minutes: this suggests that many patients considered "awake" still exhibit neurological abnormalities, such as inadequate respiratory drive.

[General anesthesia for magnetic resonance. Experience on 100 cases]

The diffusion of magnetic resonance imaging as a powerful non-invasive diagnostic procedure has led to an increasing request for general anaesthesia in patients who cannot lie still and/or who cannot guarantee adequate spontaneous breathing during the procedure. We report our own experience in 100 patients of this kind, in whom the need for general anaesthesia was due to neurological problems and/or tender age. Anaesthesia and monitoring devices were either devoted of ferromagnetic properties (allowing their location near the patient; as the ARM-S88 portable ventilator, which we used for adult patients) or connected to the patient with long connectors (allowing their location outside the resonance magnetic field; as the Draeger-Babylog pressometric ventilator, which we used in pediatric patients). On these bases administration of intravenous (86 patients) and inhalation (14 patients) anaesthesia during magnetic resonance proved safe in our experience.

[Labetalol in the prophylaxis of postoperative arterial hypertension in surgery of the posterior cranial fossa]

Increased catecholamines are one of the factors responsible for post-operative arterial hypertension. In order to prevent this severe complication labetalol, an alpha and beta blocking drug, was infused following the closure of the dura mater in half of the patients studied. For two hours after surgery blood pressure values in treated patients were constantly lower than those recorded in the control group, thus confirming the efficacy of this drug in preventing the cardiocirculatory effects of increased adrenalin and noradrenalin.

Submaximal nerve stimulation with the Datex relaxograph NMT monitor in myasthenia gravis

Recently submaximal train-of-four stimulation of motor nerves has been reported as a reliable technique for monitoring the neuromuscular function in patients awakening from anaesthesia, in order to prevent residual curarization. On the basis of the similarity between curarization and Myasthenia Gravis, we studied the neuromuscular impairment of four myasthenic patients by means of a commercially available monitor, which has been designed for routine application in the operating room. We demonstrate that the cardinal features of Myasthenia Gravis can be easily detected with this simple and painless method.

Sensitivity to curare in patients with upper and lower motor neurone dysfunction

Sensitivity to the action of nondepolarising relaxants was compared in muscles of upper and lower limbs in four syringomyelic patients undergoing elective neurosurgical procedures. It was observed that muscles with signs of lower motor neurone dysfunction are supersensitive to the action of nondepolarising relaxants. Terminal sprouting of motor axons and the occurrence of newly formed neuromuscular junctions may be responsible for a low synaptic efficacy and may explain the high sensitivity to factors that reduce the safety margin of neuromuscular transmission.

A short plasma exchange protocol is effective in severe myasthenia gravis

Plasma exchange has been reported to be a successful therapeutic procedure for the treatment of severely compromised myasthenic patients, but the optimal regimen in terms of costs or clinical benefit has not so far been determined. We have investigated the efficacy of a short plasmapheresis protocol of two exchanges 1 day apart in a series of 70 patients with severe forms of myasthenia gravis. Patients were evaluated before and 7 days after the first exchange. A positive outcome was observed in 70% of the plasma exchange cycles performed. Disease severity did not seem to be a negative prognostic factor for the efficacy of this short protocol, which was well tolerated by patients. In only 1 case were major side-effects observed. In spite of its short duration, the exchange treatment plus concomitant immunosuppressive drug therapy was not followed by early clinical deterioration.

Abnormal responses to succinylcholine and pancuronium in a patient with hemiparesis

Supersensitivity to depolarization produced by succinylcholine and resistance to pancuronium were observed in paretic muscles of a patient with a right frontoparietal tumor. The abnormal sensitivity to relaxants is compared with observations reported in patients with myasthenia gravis and hemiparesis. We hypothesize that upper motoneuron dysfunction may be followed by the appearance of "new" junctional receptors, which may occasional a supersensitivity to depolarization and a poor affinity for both curare and anti-acetylcholine-receptor antibodies. A decrease in acetylcholinesterase activity of "decentralized" muscles should also be considered.

Spinal arteriovenous fistula. A possible cause of paraparesis after epidural anaesthesia

A 62-year-old male suddenly developed a severe paraparesis after epidural anaesthesia. He recovered gradually over the next few months. He had an acute relapse one year later and a selective spinal angiography showed a dural T8 arteriovenous fistula with large draining veins. Intravascular embolisation of the fistula produced immediate and sustained clinical improvement. The mechanism commonly held responsible for neurological disturbances in spinal dural arteriovenous fistulas is cord hypoxia secondary to venous hypertension. The 20-ml of local anaesthetic solution injected into a narrow spinal canal with osteophytosis may have caused further venous engorgement, cord hypoxia and acute neurological deficit.

[Pre- and postoperative evaluation of plasma creatine kinase in 142 children subjected to "uncomplicated" anesthesia in muscle biopsy]

Pre- and postoperative serum CK activity is evaluated in 142 children submitted, "uneventfully", to diagnostic muscle biopsy under halothane (77 patients), ketamine (50 patients) or "local" (15 patients) anaesthesia. The purpose was to ascertain whether or not anaesthesia-induced-rhabdomyolysis (AR) was an asymptomatic (and unrecognized) complication of "uneventful" anaesthesia. The majority of patients with low preoperative CK values showed a slight increase of serum CK activity on the first postoperative day. On the contrary, a postoperative decrease was observed in the majority of patients with high preoperative values (namely in almost all ketamine patients and in 2/3 of halothane-patients). In no case postoperative increase reached a value suggesting the occurrence of AR even though a postoperative value of 16480 U/I was observed in a patient with Duchenne muscular dystrophy after halothane anaesthesia. Sudden interruption of motor activity induced by general anaesthesia seems to be the most important factor in reducing the release of CK from muscle. When preoperative release is low, any further postoperative reduction is not sufficient to balance the moderate increase of CK produced by the surgical procedure; the opposite should happen in patients presenting with high preoperative release. So far as anaesthetics are concerned, our data seem to suggest that ketamine has a higher "protective" role compared to halothane.

Calcium entry blocker: treatment in acute pain in cluster headache patients

15 chronic cluster headache patients in whom pain was induced by nitroglycerin received acute intravenous treatment with a calcium entry blocker. At the time of peak pain we noted a sudden decrease after the Verapamil injection. The mechanism by which the calcium entry blocker afforded relief is unlikely to have been vasodilatation in patients whose blood vessels had just been dilated by nitroglycerin. A more probable mechanism is blockade of the release of the pain-inducing neurotransmitters. The vasodilatation phase is not a primary factor in the onset of pain.