Bilateral Morgagni hernia: operative discovery of appendix lying on superior pulmonary vein.

A patient presented having an acute abdomen on a background of a twelve-month history of worsening asthma. Computed tomography showed giant bilateral intrathoracic hernias extending to both thoracic apices. Our case was unusual as the defect was bilateral and left-sided. Surgical repair revealed each hernia sac measuring >20 cm and to contain the entirety of the small bowel and colon (including retroperitoneal bowel). The appendix was discovered adjacent to right superior pulmonary vein. Both sacs were excised and the defects dissected and transfixed in a single stage operation. In the post-operative stage, he developed a 6.3 cm fluid collection anterior to the right atrium and a left-sided pleural effusion. Morgagni hernias can escape detection and be attributed to other diagnoses courtesy of false localising signs on clinical examination and symptoms in the history.

Systemic local anaesthetic toxicity from continuous thoracic paravertebral block.

Continuous paravertebral block is commonly used for post-thoracotomy analgesia and compares favourably with other systemic and regional methods with regard to safety and efficacy. No major complications of continuous paravertebral block for post-thoracotomy analgesia have been reported previously. We report here a case of systemic local anaesthetic toxicity from continuous paravertebral block administration after thoracotomy and lobectomy leading to seizure, aspiration, and ultimately, death. Potential contributing factors in this case included small patient size, concomitant antifungal therapy, extensive surgical disruption of the pleurae, and inappropriate paravertebral bolus administration. Postoperative delirium was a diagnostic confounder. We discuss the potential causes and means of avoiding similar complications in the future.

Continued experience with thoracoscopic major pulmonary resection.

Between April 1992 and March 1995, 83 patients underwent video-assisted (VATS) thoracoscopic major pulmonary resection (lobectomy: 72, bilobectomy: 4, or pneumonectomy: 7). Conversion to open thoracotomy was required in a further 21 cases (rate=20.2%). There was no in unit mortality; 2 patients died within 30 days (1.9% overall). Analysis (median values) of the VATS lobectomy cases demonstrated; operation time - 135 minutes; blood loss - 80 mls; High Dependency stay - 38 hours; total postoperative stay - 7 days. Comparison between 70 VATS lobectomies and a simultaneous group of 110 open thoracotomy cases confirmed reduced postoperative morphine consumption (83 mg open vs 57 mg VATS; p<0.001). One pneumonectomy patient exhibited a transient sympathetic dysaesthesia and one lobectomy patient developed a mild post thoracotomy pain syndrome. Long-term follow-up of VATS lobectomy for patients with primary bronchogenic carcinoma (49) revealed 1 bronchogenic cancer related death during an overall mean follow-up of 16.5 months.

Effect of hyperoxia at 1 and 2 ATA on hypoxia and hypercapnia in human skin during experimental inflammation.

Transcutaneous PO2 and PCO2 measurements and estimates of skin respiration were monitored at different levels of inspired PO2 in 20 healthy adults during the first 4 days of the tuberculin reaction, a convenient model of acute inflammation. Hyperoxia at 1 and 2 ATA significantly increased transcutaneous PO2 levels in undisturbed and in inflamed skin but did not fully correct the relative hypoxia at the site of inflammation. Hypercapnia was reduced with O2 breathing at 2 ATA. The apparent rate of O2 consumption at the reaction site was raised during hyperoxia, most prominently at 2 ATA. The most intense reactions showed a central relative slowing of laser-Doppler blood flow indicative of microcirculatory impairment. The extent of the relative hypoxia and hypercapnia was greatest in these strongest reactions. The density of lymphocytes and monocytes in biopsies of 48-h reactions was loosely related to the corresponding transcutaneous PO2 measurements. The present study provides evidence that diffusion barriers, in addition to increased local respiration, can contribute to the apparent hypoxia and hypercapnia of this inflammatory model.

Efficacy of video assisted thoracoscopic lung biopsy: an historical comparison with open lung biopsy.

BACKGROUND: Video assisted thoracoscopic lung biopsies were compared with historical controls undergoing open lung biopsy to determine the diagnostic accuracy, effect on length of postoperative stay, and cost effectiveness of the new thoracoscopic technique. METHODS: The first 25 video assisted thoracoscopic lung biopsies performed in the Edinburgh Thoracic Unit were compared with 25 historical controls for complications, diagnostic accuracy, and length of postoperative stay. RESULTS: Statistical comparison showed equal diagnostic accuracy in both groups (96% v 92%), but mean (SD) inpatient stay was reduced in the video assisted thoracoscopic group (1.4 (0.7) days) compared with those undergoing open lung biopsy (3.1 (1.8) days). No postoperative complications were reported in the group which underwent video assisted thoracoscopic lung biopsies but three patients had postoperative complications in the open lung biopsy group. CONCLUSIONS: Video assisted thoracoscopic lung biopsy is as effective in providing histological diagnosis as is open lung biopsy. All postoperative complications were related to post thoracotomy pain and occurred only in patients undergoing open lung biopsy. Reduced postoperative disability in the video assisted thoracoscopic group decreased hospital stay, offsetting the increased cost in disposables. The overall cost of video assisted thoracoscopic and open lung biopsy was 712 pounds and 1114 pounds, respectively.

Thoracoscopic pulmonary lobectomy. Early operative experience and preliminary clinical results.

Thoracoscopic video-assisted lobectomy procedures were performed in 11 patients (7 men, 4 women; age range 40 to 74 years, mean 66 years). Ten patients had peripheral pulmonary opacities: eight of these were bronchogenic carcinomas, one was an atypical carcinoid lesion, and one was a pulmonary infarct. All of these cases had preoperative evaluation by computed tomographic scanning to exclude mediastinal lymphadenopathy. The remaining patient had preoperatively diagnosed lobar bronchiectasis. Surgical access was gained via three stab (1 cm) incisions and one short (7 cm) submammary incision, which was made without rib separation and was used for specimen delivery. Lobes resected were the left upper (n = 4), left lower (n = 2), right upper (n = 2), and right lower (n = 3). All patients survived. Overall mean operative time was 3.3 hours and blood loss 263 ml. For the latter five cases, however, these figures were reduced to 2.3 hours and 100 ml, respectively, indicating improvement with experience. In no cases was ventilatory assistance required. Mean high-dependency unit time was 41 hours. In each case, it was possible to perform a standard dissectional lobectomy with lobar lymph node clearance equal to that obtained at open thoracotomy. Comparison with a series of 33 open lobectomy procedures demonstrated reduced postoperative pain, morphine consumption, and high-dependency unit stay. This preliminary experience supports the development of video-assisted thoracoscopic pulmonary lobectomy for patients with small peripheral opacities or known benign disease.

Thoracoscopy assisted pulmonary lobectomy.

BACKGROUND: This report describes a preliminary experience with six patients undergoing video imaged thoracoscopic pulmonary lobectomy. METHODS: Three left upper lobectomies, and one each of right upper, right lower and left lower lobectomy were undertaken. The resections were performed as orthodox dissectional lobectomy procedures but were carried out under videothoracoscopic imaging with instruments introduced through two stab incisions. The entire resected lobe was delivered through a 7 cm submammary intercostal incision. RESULTS: There were no operative deaths or complications attributable to the technique. In three other patients conversion to an open thoracotomy was required because of bleeding (two cases) or obscure anatomy (one case). Post-operative pain in those undergoing thoracoscopic resection was less than that encountered with standard thoracotomy and early clinic review showed the patients to be pain free with excellent shoulder movement. CONCLUSIONS: Major pulmonary resection according to standard cancer practices is feasible with videothoracoscopic techniques. This approach is likely to offer considerable functional benefit to patients. Specimen delivery through the submammary incision imposes a 5 cm primary lesion size limitation. Detailed mediastinal assessment is necessary to exclude N2 status before undertaking thoracoscopic surgery.

Circulatory adaptation to the increased metabolism in the skin at the site of the tuberculin reaction.

The sequence of changes at the site of a positive tuberculin test response were studied in 19 healthy young adults who had been immunised with BCG in childhood. The development of erythema preceded that of induration and both were most intense at 48-72 h. The strongest reactions showed higher laser Doppler (LD) flux at the periphery than at the center (central relative slowing). All showed a substantial reduction in steady-state (ss) tcpO2 from 24 h onwards and the oxygen consumption rate (mlO2.kg-1.min-1), calculated from the rate of fall in tcpO2 during temporary cuff occlusion of arterial input, was raised (greater than two-fold) throughout the period of study (to 96 h). The density of lymphocytes and macrophages in the inflammatory infiltrate in the dermis was related to the fall in tcpO2.ss and to the extent of thickening of the dermis. These experiments showed that the previously healthy dermal microcirculation can adapt to temporary increase in metabolic demands of leucocytes emigrated from the circulation into the tissue: in intense delayed hypersensitivity (DHS) reactions there is considerable hypoxia and respiratory debt, but maintenance of viability in the short-term. It is likely that similar adaptations occur in the period of establishment of microbial infection.

The effect of oxygen supplementation on post-occlusive reactive hyperaemia in human forearm skin.

The effects of raised tissue oxygen levels on reactive hyperaemia (RH) in the skin following arterial occlusion of short duration were investigated. Oxygen levels were increased by breathing 100% oxygen at 1 and 2 atmospheres absolute (ATA) in a hyperbaric chamber. Superficial skin blood flow and oxygen tension were measured throughout using a laser Doppler flowmeter and a transcutaneous oxygen monitor. The basal pre-occlusion and the maximum post-occlusion blood flows (Flb and Flmax), the time taken for flow to fall to half maximum (TR1/2), and the time for flow to return to its basal level (TR) were measured. Pre- and end-occlusion transcutaneous oxygen levels were also recorded. Oxygen breathing at 1 ATA significantly reduced TR1/2 (p less than 0.05) and at 2 ATA significantly reduced TR1/2 and TR (p less than 0.005 and p less than 0.0001) compared with control measurements during air breathing at 1 ATA. Flmax was not significantly reduced breathing oxygen at 1 or 2 ATA. These findings support the view that maximum post-occlusion blood flow in superficial skin is determined mainly by myogenic mechanisms, whereas the recovery of blood flow to basal levels is influenced largely by oxygen tension. We conclude that the direct vasoconstrictor effect of high oxygen levels is small and that the faster recovery at high tissue oxygen tensions may result from a decrease in vasodilators formed during hypoxia.

Assessment of the respiratory metabolism in the skin from transcutaneous measurements of pO2 and pCO2: potential for non-invasive monitoring of response to tuberculin skin testing.

A method is described for non-invasive transcutaneous (tc) measurement of tissue respiratory gas tensions in the skin on the forearm for study of delayed hypersensitivity reactions in man. Steady state values for tcpO2 and tcpCO2 were measured, and the skin respiratory rate (oxygen consumption) and the tissue pH were estimated from the changes in tcpO2 and tcpCO2 observed after interruption of the arterial circulation by cuff occlusion for 4 minutes. The extent of within-experiment and between subject variation in the steady-state measurements was not great (coefficient of variation 10%): tcpCO2.ss (steady state) was higher in men and tcpO2.ss was higher in women, but the extent of these sex differences was also small. Reference ranges have been established for tc measurements and calculated indices of tissue respiration in the undisturbed forearm skin of normal volunteers, against which the changes induced by tuberculin testing can be assessed. Severe changes, indicative of profound hypoxia and acidosis, are seen in intense delayed hypersensitivity reactions. Similar, but less severe changes were seen at the site of skin tests on BCG-vaccinated subjects who were 'negative' by conventional criteria of measurement of dermal induration and they became greatly exaggerated after successful re-vaccination. Intradermal injection of saline did not induce hypoxia or local acidosis. These new methods are very sensitive indicators of the tissue response in the DHS reaction.

The influence of histamine and PGE2-induced hyperaemia and oedema on respiratory metabolism in normal human forearm skin.

Transcutaneous measurements of pO2 and pCO2 were made on the forearm skin after intradermal injection of histamine, PGE2, and saline. The mediators, used at concentrations which induce intense hyperaemia, did not modify the steady state tcpO2/pCO2 levels measured with a sensor head temperature of 44 degrees C when breathing air or hyperbaric (2ATA) oxygen. It was deduced that gas transport is unaffected by mediator-induced conditions in the skin. The rates of fall of tcpO2 and of rise of tcpCO2 after arresting the forearm circulation by cuff occlusion of the arm were significantly less at the histamine site than at the PGE2 and saline sites. The values over the PGE2 and saline injection sites were less than those over undisturbed skin. The dynamic tests of respiratory gas exchange indicate that the skin metabolic rate is reduced at all injection sites and the greatest effect was seen with histamine. Measurement of dermal thickness after saline injection has shown that the excess interstitial fluid persists at the time of maximal hyperaemia: this is further accentuated at the histamine site through active oedema formation. Accumulation of excess interstitial fluid (persistence of aqueous injection or oedema generated by the action of mediator) separates the tissue cells. The reduction in the number of cells per unit volume is sufficient to explain the observed reduction in oxygen consumption per unit volume of skin. It is concluded that the increased diffusional distances in mediator-induced oedema are unimportant for the respiration of otherwise normal tissues, but that oedema by reducing oxygen flux may contribute appreciably to the hypoxia of inflamed tissue infiltrated with metabolically active cells.