Assessment of postoperative pain: impact of clinical experience and professional role

Background: Unrelieved postoperative pain is still reported to be a rather common clinical problem which may be related to inadequate routines for pain assessment. Therefore, the aim of the study was to describe strategies used by experienced and less experienced nurses and physicians in their assessment of postoperative pain and to relate different approaches, clinical experience, and professional role to the accuracy of the pain ratings.
Methods: Data collection was based on repeated interviews with nurses (n=30) and physicians (n=30) in connection with clinical pain assessments (n=180) including VASscoring
Results: Commonly used strategies in the pain assessment were: - how the patient looks, - what the patient says, - the manner of talking, and - past experience of similar circumstances. The mean VAS-score given by the patients (6.1±21.1) was significantly (P<0.001) higher than that rated by the staff members (4.9±21.2). Nurses as well as physicians overestimated low and underestimated high levels of pain indicated by the patients. The accuracy of the ratings by nurses, especially by more experienced ones (≤10 years in nursing), was found to be less precise than that of physicians. The pain assessment of these very experienced nurses was characterized by a systematic underestimation.
Conclusions: The present study emphasizes a need for definition of more precise strategies for clinical postoperative pain assessment which better take into consideration the pain experiences and needs of individual patients     

Percutaneous radiofrequency rhizotomy of lumbar spinal facets: The results of 46 cases

The results of percutaneous radiofrequency rhizotomy of lumbar spinal facets in 46 patients followed at least three months (mean 15 months) are reported and compared with those reported previously. Satisfactory pain relief three months after the procedure was achieved in 36.4 percent of patients without operations and in 41.7 percent of patients with operations other than fusion.No patient had previously undergone fusion.Treatment of low-back pain by using radio-frequency thermocoagulation of spinal facets is a simple, safe, and well-tolerated procedure. It can be used to relief of pain in spite of decreasing rates of success within the follow-up period.     

Bilateral continuous paravertebral block used for postoperative analgesia in an infant having bilateral thoracotomy

We describe the successful postoperative pain management in an 11-month-old infant who underwent bilateral thoracotomy, using continuous infusions of bupivacaine into two directly placed paravertebral catheters. Haemodynamic parameters and pain scores were measured 1–2 h for 60 h while the infusions were continued and, intermittently, blood samples were taken for subsequent measurement of serum bupivacaine concentrations. The technique provided effective pain relief and the infant required no other analgesia postoperatively. There were no adverse haemodynamic consequences or complications relating to either catheter placement or drug infusions. Serum concentrations of bupivacaine remained below toxic levels throughout the study period, though accumulation did occur.     

Convergence of occipital nerve and superior sagittal sinus input in the cervical spinal cord of the cat

Co-existence of facial and occipital pain may occur in occipital neuralgia, migraine and cluster headache; suggesting convergence of trigeminal and cervical afferents. Such convergence has been shown in humans and other animals, but the site and extent of this are uncertain. In anaesthetized adult cats, the superior sagittal sinus and occipital nerve were stimulated electrically, and extracellular recordings made in the dorsolateral area of the upper cervical cord using glass-coated tungsten electrodes. Of 49 units in 10 cats, 33 (67%) had input from the superior sagittal sinus and the occipital nerve. Thirteen (27%) had superior sagittal sinus input and 3 (6%) had occipital nerve input. Convergent receptive fields were identified mechanically in 7 units. These experiments in cats show convergent input from occipital nerve and superior sagittal sinus on dorsolateral area units in two-thirds of cases studied. This experimental site of trigeminocervical convergence may relate to referral of pain in occipital neuralgia and other headaches.     

痛力克对癌症疼痛镇痛效果的临床观察

应用印度ＬＵＰＩＮ公司提供的痛力克（酮酷酸氨丁三醇 ）对中重度癌症疼痛３０例进行镇痛效果的临床观察，有效率９３％，平均显效时间９ｍｉｎ，均数缓解时间５．１ｈ，并用哌替啶做了同期交叉自身镇痛对比研究，结果表明：两药的镇痛效果相似（Ｐ＞０．０５），但痛力克的不良反应发生率明显低于哌替啶。     

Initial cranial CT scan for the assessment of prognosis in head injury

Summary A total of 208 multiple trauma patients with head injury (HI) were investigated who had been treated in the period from 1990 to 1995. The average age was 35.2 ± 17.7 years; the injury severity according to ISS was 30.2 ± 8.6 points; 20.5 % died as a result of the HI; the mortality of all patients was 26.5 %. The Glasgow Coma Scale (GCS) was determined at an average of 22 min after trauma (8.0 ± 4.3 points) at the scene of accident. The patients were classified according to GCS into minor HI (group 1: 14–15 points), moderate HI (group 2: 9–13 points) and severe HI (group 3: 3–8 points). Patient outcome was assessed by the Glasgow Outcome Scale (GOS) and was classified as good (GOS 4 and 5) and poor (GOS 1, 2 and 3) outcome. At the latest, 2 h after trauma, a CT scan of the head (CCT) was done. The HI groups are compared regarding frequency of types of injury. In all HI groups the fractures of the bony face occurred at the same frequency (36.0–38.9 %). The frequency of calotte fractures (Kal-Fx) increased from group 1 (8.0 %) to 2 (19.2 %) and 3 (25.6 %); fractures of the skull base significantly differed between group 1 (16.0 %), 2 (7.8 %) and 3 (33.4 %). Epidural hemorrhage (EDB) appeared only in group 2 (7.8 %) and 3 (6.7); subdural hemorrhage was found in group 1 (2.7 %), 2 (7.8 %) and 3 (10.0 %). Subarachnoid hemorrhage (SAB) was significantly more frequently seen, dependent on HI severity, in group 3 (26.7 %) compared to group 2 (11.7 %) and 1 (8.0 %). Intracerebral contusion (ICK) significantly increased from group 1 (12.0 %) to 2 (27.3) and 3 (45.6 %). Brain swelling (BS) also significantly increased from group 1 (8.0 %) to 2 (19.5 %) and 3 (49.0 %) and lesions of ventricles (VL) from group 1 (2.7 %) to 2 (11.7 %) and 3 (20.0 %). Midline shift (13.4 %) and signs of herniation (4.5 %) only occurred in group 3. The analysis of correlation/regression and receiver operating characteristics was able to predict 79 % of patients' outcome accurately using GCS (r 0.54; P < 0.0001) alone, using CCT (r 0.65; P < 0.0001) 87 % were correctly predicted with significant variables Cal-Fx, EDB, SAB and BS. CCT with GCS (r 0.74; P < 0.0001) were able to predict 88 % accurately with significant variables Cal-Fx, EDB, BS and GCS. The combination of CCT with GCS, age and ISS (r 0.78; P < 0.0001) was able to predict only 87 % correctly, although the r value was the highest; significant variables were Kal-Fx, EDB, BS, VL, GCS, age and ISS.      

β-endorphin in the brain. A role in nociception

We have known the endogenous opioid peptide β-endorphin for 20 years. Surprisingly, our knowledge of the physiological role of this peptide and its receptors in modulation of pain perception is still fragmentary. Whereas most studies have tried to elucidate the physiological role of β-endorphin by reversing evoked responses by the opioid antagonist naloxone, this review focuses on quantification of release of β-endorphin in the brain as the approach to define physiological and pathophysiological roles of β-endorphin in relation to nociception. Using a lateral ventricle-cisterna magna perfusion model in the anesthetized rat, it was shown that depolarization of neurons in the arcuate nucleus of the hypothalamus, where β-endorphin is produced, was followed by release of β-endorphin to the cerebrospinal fluid compartment. Intense activation of spinal nociceptive pathways by intrathecal capsaicin injections also led to β-endorphin release. It is concluded that there may still be good reason to quantify β-endorphin in human cerebrospinal fluid to elucidate the role of β-endorphin in pain perception.