VISIBLE CHANGES IN RESPIRATORY RHYTHM Cheyne-Stokes Respiration.-This is characterized by visible irregularity of breathing. The respirations, shallow at first, gradually increase in depth and rapidity, to be followed after gradually diminishing excursions by complete apnea, lasting sometimes nearly 30 seconds (Fig. 37). It occurs in the coma of uremia, apoplexy, meningitis, opium poisoning, etc. Blood-pressure is higher during the hyperpneic periods, in cases associated with increased intracranial tension. It is due to an obtunded sensibility of the medulla to CO2. Deep breathing carries off the excess of this substance and the respiratory center remains inactive until another FIG. 38-Tracing from a child of 8 years, showing typical Biot's breathing. Note the pauses which occur at irregular intervals and vary in length, the frequent deep sighs, and the constant irregularity of the respirations in force and rhythm. (Conner and Stillman.) over-accumulation of this gas has taken place. Cheyne-Stokes respiration is of grave, but not necessarily fatal, import. In children, if associated with other suggestive symptoms, it points gravely toward a meningitis. Biot's Breathing. This type of breathing differs from that just described, in that a series of rapid but equally deep respiratory movements is followed by a sudden apnea. There is no gradual increase and decrease in the depth of respirations (Fig. 38). It may be regarded as almost pathognomonic of meningitis (Conner and Stillman'). CONNER and STILLMAN: "A Pneumographic Study of Respiratory Irregularities in Meningitis." Arch. Int. Med., ix, 1912, 203. CHAPTER II PALPATION By palpation we refer to the use of the sense of touch for the determination of the physical character of the tissues. It is employed: 1. To elicit tenderness, or rigidity. 2. To determine the presence of the cardiac impulse, pulsations or thrills, and to feel the pulse (see Chap. XIII). 3. To determine the character of the skin (temperature, moisture, texture, edema). 4. To discover local swelling, induration, softening, etc., of the tissues, especially as regards the lymph nodes. FIGS. 39 AND 40.-Palpation to determine expansion and vocal fremitus. 5. To estimate the degree and equality of chest expansion. 7. To determine the presence of hepatic or splenic enlargement, pulsation of the liver, etc. Chest Expansion. The bilateral equality of chest expansion can often be satisfactorily determined by laying the hands lightly upon the patient's chest during the act of respiration. Some examiners prefer this method to simple inspection. ZONES OF CUTANEOUS HYPERESTHESIA (HEAD'S AREAS), AND REFLEX PAIN "The nerves supplying the skin and skeletal muscles have become so educated that any injury to them is accurately located. Such is not the case with nerves of the internal organs. A painful irritation of the viscera finds expression, not necessarily over the site of the organ, but in a painful area of the skin often remote from it. Head has shown that the painful stimulus in the organ travels in a centripetal direction to the posterior part of the cord and there sets up excitation of the nerves which in the same and in the adjoining segments supply the peripheral surfaces with sensation. The pain is referred to the skin because therein the pain sense reaches its highest development. "1 FIG. 41. Referred pleural pain. The horizontal lines indicate the location of intercostal nerve pain; the dots represent phrenic nerve pain, on the anterior surface of the body. "Referred pain from the viscera has these characteristics to differentiate it from pain of peripheral origin: (1) It is often remote from the site of irritation. (2) It follows the lines on the skin of the spinal segmentation rather than the course of the peripheral nerves. (3) It is usually associated with cutaneous hyperesthesia and tenderness to pressure. (4) Often the pain fails to involve the whole segmental area of the skin, but finds expression in one or more points of maximal tenderness and spontaneous pain." Examples. The pain of biliary colic is felt at the angle of the scapula, that of renal colic in the testicles, while heart pain is referred to the arm or the neck. Hyperesthesia of the skin is determined by light pressure with a dull object such as the head of a pin, or by slight pinching. Muscular rigidity 1 CAPPS: Arch. Int. Med., December, 1911.; or spasm which may have a similar genesis is elicited by estimating the degree of muscular tonus by means of our sense of touch. PLEURAL PAIN The parietal pleura and outer part of diaphragm receive their nerve supply from the lower six intercostal nerves. Lesions in this region produce pain in the overlying skin, which may be regarded as the result of a peripheral neuritis. Cutaneous hyperesthesia is absent. Irritation FIGS. 42 AND 43.-Referred cardiac pain. Showing the area of pain and cutaneous hyperesthesia requently met with in angina pectoris. The segmental distribution (third cervical, to the third dorsal) is indicated by the Roman numerals. Other segments may, however, be involved, the sixth dorsal causing epigastric pain, and the upper cervical roots, pain in the neck and back of the head. The characteristic sense of thoracic constriction has been explained as resulting from reflex stimulation of the intercostal muscles, and the sense of impending dissolution has been likened to the violent stimulation of the nervous system produced by excitation or injury of other viscera, as by a blow on the testicles or over the solar plexus. (Mackenzie.) In pulmonary disease cutaneous hyperalgesia occurred in 3 per cent. of the 460 cases studied by Langstroth and in 13 per cent. of those who complained of pain. In disease of the heart and aorta the hyperalgesia was noted in 7 per cent.; and in 18 per cent. of the cases having pain. As a diagnostic aid the occurrence of Head's hyperalgesic zones is generally disappointing, owing to the large number of areas over which disease of a given viscus may cause sensory changes. of the posterior part produces pain in lower chest, abdomen or lumbar region. This is a referred pain-by way of the seventh to the twelfth dorsal segments. The visceral pleura is devoid of the pain sense. The central diaphragmatic pleura is supplied by the phrenic nerve. Irritation of this region produces pain and tenderness in the neck, especially along the ridge of the trapezius muscle, often with a surrounding zone of hyperesthesia (Fig. 41). This is a true referred pain-by way of the third and fourth spinal segments. The pericardial pleura when irritated may produce similar pain, because its nerve supply is mainly if not entirely phrenic in origin (Capps). Pleural pain may be referred to the abdominal wall and lack of a careful examination of the lungs has led to unwarranted celiotomies in patients who a day or two later have developed well-marked signs of the pneumonia which was the cause of the original abdominal pain and rigidity. Vice versa, although less frequently, abdominal lesions may occasionally produce thoracic pain. TACTILE OR VOCAL FREMITUS Fremitus is the tactile perception of vibrations, which may be produced by (1) phonation (vocal fremitus), (2) coughing (tussive fremitus), (3) breathing (rhoncal fremitus) produced by exudation into or stenosis of the air passages. FIG. 44.-Ulnar palpation. The lower pulmonary border can be accurately determined by laying the ulnar surface of the hand and little finger against the chest wall while the patient counts one-one-one-. (See Fig. 50.) These phenomena set up vibrations within the bronchi and lungs, which under favorable conditions are accompanied by objectively sensible vibrations of the chest wall, which can be felt when the hand is laid upon it, as a faint vibration or trembling of its surface. The sensation thus obtained has been likened to that derived from a purring cat, but in the case of human fremitus the vibrations are much finer and more rapid. Vocal fremitus, which only is of practical utility, is elicited by laying the ulnar surface of the hand or fingers upon the chest or in the inter |
