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Biomedical subjects

H Kehlet

Publications and source records attributed to H Kehlet.

At least 253 records · Page 14Linked to original sources

The surgical stress response: should it be prevented?

Postoperative complications such as myocardial infarction, pulmonary infection, thromboembolism and fatigue are probably related to increased demands, hypermetabolism, catabolism and other physiologic changes included in the global "surgical stress response." Strategies have been developed to suppress the detrimental components of the stress response so as to improve postoperative outcome. Of the various techniques to reduce the surgical stress response, afferent neural blockade with regional anesthesia to relieve pain is the most effective, although not optimal. Data from numerous controlled clinical trials have demonstrated a reduction in various aspects of postoperative morbidity by such a nociceptive blockade. Although a causal relationship has still to be demonstrated, these findings strongly argue the concept of "stress-free anesthesia and surgery" as an important instrument in improving surgical outcome.

Humans↗

Ranitidine improves certain cellular immune responses in asymptomatic HIV-infected individuals.

Human immunodeficiency virus (HIV) infection is characterized by a progressive impairment in immunocompetence leading to severe opportunistic infections and malignancies. In a double-blind, placebo-controlled study, the potential impact of immunomodulation by oral ranitidine, 600 mg daily, for 28 days was studied in 18 HIV-positive patients (CDC group II). All were without clinical signs of infections and were not treated with other known immunomodulating agents. Several immunological parameters related to HIV infection were studied and confirmed to be impaired early in HIV infection. Spontaneous and in vitro interleukin-2- and interferon-alpha-stimulated natural killer cell activity improved in the ranitidine-treated patients in contrast to a decrease in nontreated patients (#p less than 0.03, #p less than 0.01, #p less than 0.02 between groups, respectively). Furthermore, T-cell blastogenesis to phytohemagglutinin stimulation and soluble interleukin-2 receptors in serum increased in ranitidine-treated patients compared with nontreated patients (#p less than 0.01). However, ranitidine treatment did not change CD4+ cell counts. Although the significant improvement in immunocompetence shown in this study is small, the present result indicates the need for further trials with immunomodulation by ranitidine in HIV-infected individuals.

Adult↗

Comparison of the effects of SAG-M and whole-blood transfusions on postoperative suppression of delayed hypersensitivity.

The influence of perioperative whole-blood transfusion and transfusion with erythrocyte suspension (SAG-M blood) on postoperative depression of cell-mediated immunity (CMI) was investigated in 67 patients who underwent elective resection for colorectal cancer. Cell-mediated immunity was assessed pre- and postoperatively by skin testing with seven common delayed-type hypersensitivity (DTH) antigens. The postoperative skin-test response decreased more in the patients who received whole blood (15 patients) than in those who received SAG-M blood (16 patients) (60% versus 42%, p less than 0.001) and in those who did not receive a blood transfusion (36 patients) (60% versus 40%, p less than 0.001). The enhanced postoperative immunosuppression in patients who received whole-blood transfusions persisted after matching according to age, sex, height, weight, hemoglobin and serum albumin levels, duration of surgery and diagnosis. Thus, perioperative transfusion with SAG-M blood does not enhance surgically induced immunosuppression as effectively as does transfusion with whole blood.

Adult↗

[Treatment of postoperative pain].

Intensive research during recent years concerning treatment of postoperative pain has demonstrated that the majority of operation patients can be rendered free from pain but that this is far from being the case in clinical practice. This article reviews the physiological mechanisms of acute pain and the methods available for treatment of pain related to acute physiology of pain. Postoperative treatment of pain should be aggressive with the object of preventing pain and normalizing the vital functions with the object of reducing the perioperative morbidity and mortality. A series of recommendations are given for treatment of pain after surgical intervention.

Analgesia↗

[Assessment of early postoperative convalescence by a simple scoring system].

Fifty patients in classes 1-2 of the American Society of Anaesthesiologists (ASA) were submitted to major elective abdominal surgery. They were anaesthetised with a balanced technique and were assessed preoperatively and daily until the tenth postoperative day by a simple scoring system based on self-care. The total score fell significantly to a minimum on the first postoperative day and remained significantly decreased but with an increasing tendency until the tenth postoperative day. Patients with wound or respiratory complications had significantly lower scores than patients without complications on the sixth to ninth days. It is concluded that this simple scoring system is useful for monitoring early postoperative morbidity and it may prove of value in future investigations of surgical therapeutic regimes.

Convalescence↗

Skeletal muscle enzyme activities and metabolic substrates during exercise in patients with postoperative fatigue.

Subjective fatigue was quantified before and 20 days after uncomplicated elective abdominal surgery in 12 patients and compared with changes in heart rate, enzyme activities and skeletal muscle substrates before and after bicycle exercise for 10 min at 65 per cent of patients' preoperative maximum work capacity. Fatigue increased from a mean(s.e.m.) preoperative level of 2.5(0.5) arbitrary units to 4.6(0.5) on postoperative day 20 (P less than 0.01). Body-weight, triceps skinfold thickness and arm circumference decreased postoperatively (P less than 0.02). Postoperative values of muscle enzyme activities indicative of oxidative phosphorylation capacity (citrate synthase and 3-OH-acyl coenzyme A dehydrogenase) were lower than preoperative values (P less than 0.05). Lactate dehydrogenase was unaltered and resting values of muscle glycogen and adenosine triphosphate were higher after operation (P less than 0.05). In response to exercise, heart rate, muscle glucose, glucose-6-phosphate and lactate increased (P less than 0.05), while muscle glycogen and creatine phosphate decreased (P less than 0.05). Increase in postoperative fatigue correlated with the increase in heart rate (P less than 0.05), while no significant correlations were found between fatigue and muscle parameters. Our results suggest that lack of exercise and malnutrition may be of importance in the decrease in work capacity and in fatigue after operation.

Abdomen↗

Prevention of postoperative pain by balanced analgesia.

Fourteen patients undergoing colorectal surgery received an intraoperative afferent neural block with combined intrathecal and extradural local anaesthetics plus a balanced postoperative low-dose regimen of extradural bupivacaine 10 mg h-1-morphine 0.2 mg h-1 and systemic piroxicam 20 mg/24 h. Postoperative pain, assessed repeatedly during the initial 48 h, was prevented during rest, mobilization from the supine to the sitting position and during walking, in all but one patient; slight pain was observed intermittently during coughing in four patients.

Adult↗

Effect of surgery on sensory threshold and somatosensory evoked potentials after skin stimulation.

We have studied the effect of surgical injury on cutaneous sensitivity and somatosensory evoked potentials (SSEP) to dermatomal electrical stimulation in 10 patients undergoing hysterectomy. Forty-eight hours after surgery, sensory threshold increased from 2.2 (SEM 0.3) mA to 4.4 (1.1) mA (P less than 0.01) and SSEP amplitudes in P1, N1, P2 and the peak-to-peak amplitudes decreased (P less than 0.05). Latency was prolonged only in the N3 component (P less than 0.05). No changes were seen in threshold and SSEP in a control group studied over the same interval. The results suggest that surgical injury activates antinociceptive modulatory systems.

Adult↗

Late postoperative episodic and constant hypoxaemia and associated ECG abnormalities.

Twenty-two patients without cardiopulmonary disease and undergoing elective major abdominal surgery were monitored continuously with a Holter tape recorder and a pulse oximeter on one night before operation and the first two nights after operation (23:00 to 07:00), without oxygen therapy. Mean heart rate increased 16 beat min-1 (P less than 0.001) and mean oxygen saturation (SaO2) decreased 2.6% (P less than 0.001) after operation. Episodic oxygen desaturation to less than 80% occurred in four patients before operation, but in 13 patients after operation (P less than 0.05). ECG abnormalities were observed in 10 patients before operation and in 16 patients after operation (ns). Individual maximum ST depression was more pronounced after than before operation (P less than 0.05). Episodic desaturation was related closely to tachycardia in six patients before operation and one patient after operation; before operation to atrioventricular block in one patient, and after operation to ST depression in two patients. Mean SaO2 on the second night after operation correlated with total dose of opioid for pain relief (rs = -0.48; P less than 0.05), and postoperative decrease in SaO2 correlated with postoperative increase in heart rate (rs = -0.43; P less than 0.05). No patient had postoperative cardiac complications indicating treatment.

Aged↗

The effect of 0.5% ropivacaine on epidural blood flow.

Twenty patients scheduled for elective abdominal surgery received epidural analgesia with 20 ml 0.5% ropivacaine or 0.5% bupivacaine. Epidural blood flow was measured by an epidural 133Xe clearance technique on the day before surgery (no local anaesthetic) and again 1 h before surgery, 30 min after injection of the local anaesthetic during continuous infusion (8 ml/h). Median initial blood flow was 5.0 ml/min and 6.0 ml/min per 100 g tissue in patients receiving ropivacaine and bupivacaine, respectively. After epidural bupivacaine, blood flow increased in 8 of 10 patients to 6.9 ml/min per 100 g tissue (P less than 0.05) in contrast to a decrease in 9 of 10 patients to 3.3 ml/min per 100 g tissue after ropivacaine (P less than 0.05), (P less than 0.01 between groups). The median level of sensory analgesia was T3.5 and T4.5 in the ropivacaine and bupivacaine group, respectively (P greater than 0.05). The demonstrated vasoconstrictor effect of epidural ropivacaine may influence the duration of its local anaesthetic effect.

Adult↗

Pressure pain thresholds in volunteers and herniorrhaphy patients.

Pressure algometry is a method to estimate pressure pain sensitivity in tissues. The aim of the present study was to evaluate the reproducibility of pressure pain thresholds (PPT) in the abdominal integument and to evaluate the use of pressure algometry as a measure of wound tenderness following surgery. PPT was determined in 20 healthy volunteers on two separate examinations, and in 14 patients at the incisional site before and following inguinal herniotomy. In volunteers, PPT was higher for men than for women, and no difference was observed between the first and second day of examination. In surgical patients a significant decrease in PPT was observed following operation. Morphine 0.07 mg/kg caused a slight but significant increase in PPT. Pressure algometry may be useful to study nociceptive mechanisms and the dynamics of wound pain in surgical patients.

Abdomen↗

Endocrine, metabolic and cardiovascular responses to adrenaline after abdominal surgery.

Adrenaline-induced changes in heart rate, blood pressure, plasma adrenaline and noradrenaline, cortisol, glucagon, insulin, cAMP, glucose lactate, glycerol and beta-hydroxybutyrate were studied preoperatively and 4 and 24 h after skin incision in 8 patients undergoing elective cholecystectomy. Late postoperative responses of blood glucose, plasma cAMP, lactate and glycerol to adrenaline infusion were reduced, whereas other responses were unaffected. Blood glucose appearance and disappearance rate as assessed by [3H]3-glucose infusion was unchanged pre- and postoperatively. The increase in glucose appearance rate following adrenaline was similar pre- and postoperatively. These findings suggest that several beta-receptor-mediated responses to adrenaline are reduced after abdominal surgery.

Adult↗

Continuous assessment of oxygen saturation and subcutaneous oxygen tension after abdominal operations.

Ten patients undergoing abdominal operations had oxygen saturation (SpO2) and transcutaneous (PtcO2) and subcutaneous (PscO2) oxygen tensions monitored continuously during the second and third postoperative nights from 11 pm to 7 am. At the end of the second postoperative night an oxygen stimulation test (10 l/min by face mask) was carried out in eight of the 10. Median SpO2 was 91% (range 82-95) on the second, and 91% (86-95) on the third, postoperative nights, respectively. Six patients had intermittent episodes of desaturation to less than 80%, each of less than one minute's duration. PtcO2, but not PscO2, followed the episodic variations in SpO2. PscO2 was 58 mmHg (46-69) on the second postoperative night and 61 mmHg (48-71) on the third postoperative night. PscO2 correlated with SpO2 in all but one patient who had lower PscO2 than expected from the measured SpO2 and estimated PaO2. Oxygen treatment increased individual PscO2 by 14 mmHg (9-49), PtcO2 by 38 mmHg (10-104), and SpO2 to 99% (95-100), but stable PscO2 was not achieved within the 20 minute period of treatment. These results obtained during continuous measurements show pronounced intersubject differences in oxygen tensions near the surgical wound in the late postoperative period. The results suggest that pulmonary oxygenation is the most important determinant of mean subcutaneous oxygen tension after uncomplicated elective abdominal operations.

Abdomen↗

Effect of combined prednisolone, epidural analgesia and indomethacin on pain, systemic response and convalescence after cholecystectomy.

Twelve patients undergoing elective cholecystectomy received as analgesic medication a single dose of methylprednisolone (30 mg/kg) preoperatively and thoracic epidural analgesia with plain bupivacaine for 48 hours + epidural morphine 4 mg and systemic indomethacin 100 mg, both every 8 hours for 96 hours. Assessments of pain, various parameters of response to injury, peak flow and subjective fatigue were made preoperatively, before and 3 and 6 hours after skin incision and 1, 2, 4 and 8 days postoperatively. These patients were matched with 24 from a previous study who were treated with either intermittent nicomorphine and acetaminophen or with epidural analgesia + systemic indomethacin as analgesic medication. Preoperative methylprednisolone resulted in improved pain relief, with concomitantly reduced need for epidural bupivacaine, prevention of hyperthermic response, improved postoperative pulmonary function and lessened fatigue, while the leucocytic and acute phase responses were unmodified. There were no side effects. These results may be explained by inhibition of various trauma-induced inflammatory mediators.

Adult↗

[Late episodic hypoxemia and variation in heart rate following major abdominal surgery].

In thirteen patients who were submitted to elective major abdominal surgery, the heart rate and arterial oxygen saturation were monitored continuously on the preoperative night-to-day prior to operation and the first and second postoperative nights (from 11 pm till 7.30 am). The heart rate increased by an average of approximately 22 beats/minute (p less than 0.005) and the oxygen saturation decreased approximately 4.5% (median) (p less than 0.003) after the operation. During the second postoperative night, two patients had 120 and 372 episodes respectively of sudden decrease in saturation to less than 80%. On the morning of the third day, the second of these patients developed cardiac arrhythmia requiring treatment. In one of these patients, the episodes were closely correlated with increase in the heart rate. No connection was observed between administration of opiates and disturbances in oxygen saturation or heart rate. The clinical relevance of episodic decrease in saturation in the late postoperative phase is still unknown but may be of significance for the development of cardiac and cerebral dysfunctions.

Abdomen↗